JP6986387B2 - Electronic percussion instrument - Google Patents

Description

The present invention relates to an electronic percussion instrument, and more particularly to an electronic percussion instrument capable of quickly calculating a striking position.

In an electronic percussion instrument typified by an electronic drum or the like, a striking sensor for detecting a striking is provided, and the striking position is detected based on the waveform detected by the striking sensor. Specifically, when the striking surface is struck, the farther the striking position is from the striking sensor, the shorter the initial half wave of the waveform detected by the striking sensor, and as the striking position approaches the striking sensor, the initial half wave. The waves get longer.

Under such circumstances, in the electronic percussion instruments of Patent Documents 1 and 2, one striking sensor is provided in the center of the striking surface, and the striking position from the striking sensor is detected by the length of the initial half wave of the waveform detected by the striking sensor. ing. However, when a hit is made near the center of the hitting surface where the hitting sensor is arranged, the initial half wave of the waveform becomes long, so it is necessary to sufficiently lengthen the detection time in order to detect the hitting position in such a case. Therefore, the pronunciation instruction of the striking sound is delayed by that amount. On the contrary, if the hit detection time is shortened in order to avoid the delay of the sounding instruction of the hitting sound, only the hitting position around the hitting surface can be detected.

On the other hand, in the electronic percussion instruments of Patent Documents 3 to 7, a plurality of hitting sensors are arranged on the hitting surface, and the hitting position is calculated based on the detection result of each hitting sensor, so that the vicinity of the hitting sensor is hit. Even in this case, the striking position is calculated quickly, and the delay in the pronunciation instruction of the striking sound is eliminated. Similarly, in the electronic percussion instruments of Patent Documents 8 to 11, a central sensor is arranged in the center of the striking surface and peripheral sensors are arranged around the striking surface to quickly calculate the striking position and instruct the sound of the striking sound. The delay of is eliminated.

Japanese Unexamined Patent Publication No. 10-020854 Japanese Unexamined Patent Publication No. 10-11169 Japanese Unexamined Patent Publication No. 62-501653 Japanese Unexamined Patent Publication No. 05-232943 Japanese Unexamined Patent Publication No. 2005-037922 Japanese Unexamined Patent Publication No. 2011-158594 Japanese Unexamined Patent Publication No. 2014-119664 Jikkai Sho 54-172726 Japanese Unexamined Patent Publication No. 2012-203191 Japanese Unexamined Patent Publication No. 2009-186886 Japanese Patent Publication No. 2014-524008

However, even with an electronic percussion instrument equipped with these multiple striking sensors, if the diameter of the striking surface becomes large, it takes a long time for the striking sensor located away from the striking position to detect the striking. There is a problem that the calculation of the hitting position is delayed, and as a result, the pronunciation instruction of the hitting sound is delayed.

The present invention has been made to solve the above problems, and an object of the present invention is to provide an electronic percussion instrument capable of quickly calculating a striking position.

The electronic striking instrument according to claim 1 includes a striking surface and a striking sensor that detects an impact on the striking surface, and the striking sensor is the center of the striking surface when the striking surface is viewed in a plan view. When the central sensor arranged in the portion and one or more peripheral sensors are configured, and the initial half wave of the impact waveform is detected within a predetermined time after the central sensor detects the impact. , The first position calculating means for calculating the impact position from the central sensor based on the initial half wave, and the impact detection of a plurality of sensors in the central sensor or the peripheral sensor including at least one peripheral sensor. It is provided with a second position calculating means for calculating the striking position based on the difference, and a sounding instruction means for instructing the sounding of the striking sound based on the striking position calculated by the first and second position calculating means. When the striking surface is hit, the sensor is within a region where the peripheral sensor can detect the hit within a predetermined time after the central sensor detects the hit, and the central sensor hits the hit. Within a predetermined time after detection, the central sensor is arranged in a region where the initial half wave of the impact waveform can be detected.

The electronic hitting instrument according to claim 2, wherein, in claim 1, at least three peripheral sensors are arranged at equal intervals on the circumference centered on the central sensor, and the three peripheral sensors are used. When any position in the formed circumference is hit, the hit surface is within the region where the peripheral sensor can detect the hit within a predetermined time after the central sensor detects the hit. The second position calculation means is arranged in a region where the central sensor can detect the initial half wave of the impact waveform within a predetermined time after the central sensor detects the impact when the impact is applied. Based on the difference in impact detection of each peripheral sensor, the impact position in the circumference in which each peripheral sensor is arranged is calculated.

The electronic percussion instrument according to claim 3 is provided with a striking position table in which the difference in striking detection of each peripheral sensor is used as a variable and the striking position corresponding to the variable is stored. , The striking position is calculated based on the striking position table.

The electronic hitting instrument according to claim 4, wherein in claim 1, the peripheral sensor is composed of a ring sensor formed in a circular shape centered on the central sensor, and the circumference formed by the ring sensor. When any of the positions is within the region where the ring sensor can detect the impact within a predetermined time after the central sensor detects the impact, and the striking surface is impacted. Within a predetermined time after the central sensor detects the impact, the central sensor is arranged in a region where the initial half wave of the impact waveform can be detected, and the second position calculation means is the same as the central sensor. Based on the difference in impact detection from the ring sensor, the impact position in the circumference in which the ring sensor is arranged is calculated.

The electronic percussion instrument according to claim 5 performs a weighting operation on the striking position calculated by the first position calculating means and the striking position calculated by the second position calculating means in any one of claims 1 to 4. A third position calculating means for calculating a striking position is provided, and the sounding instruction means instructs the sounding control means to pronounce a striking sound based on the striking position calculated by the third position calculating means. Is.

According to the electronic percussion instrument according to claim 1, when the striking surface is hit, the first position calculating means calculates the hitting position from the central sensor based on the initial half wave detected by the central sensor, and the second position is calculated. The calculation means calculates the striking position based on the difference in striking detection of a plurality of sensors among the central sensor or the peripheral sensor including at least one peripheral sensor. The pronunciation of the striking sound is instructed by the sounding instruction means based on the striking positions calculated by the first and second position calculating means.

Now, when the striking surface is impacted, if the central sensor can detect the initial half wave of the impact waveform within a predetermined time after detecting the impact, the impact position is calculated by the first position calculation means. can. Here, when the striking surface is struck, the problem is that the central sensor cannot detect the initial half wave of the striking waveform within a predetermined time after detecting the striking.

However, when the striking surface is hit, the peripheral sensor is within the region where the peripheral sensor can detect the hit within a predetermined time after the central sensor detects the hit, and the central sensor detects the hit. Within a predetermined time after the detection, the central sensor is arranged in the region where the initial half wave of the impact waveform can be detected. Therefore, when the striking surface is hit, the central sensor or the peripheral sensor is predetermined even if the initial half wave of the hitting waveform cannot be detected within a predetermined time after the central sensor detects the hit. Since the impact can be detected in time, the impact position can be calculated by the second position calculation means based on the difference in impact detection of the central sensor or a plurality of sensors among the peripheral sensors including at least one peripheral sensor. By disposing the central sensor and the peripheral sensor in this way, the striking position can be calculated based on the detection result within a predetermined time. Therefore, even when the striking surface is formed to be large, the striking position can be calculated quickly, so that the pronunciation instruction of the striking sound is not delayed.

According to the electronic percussion instrument according to claim 2, in addition to the effect of claim 1, the following effects are exhibited. That is, within the circumference in which the three peripheral sensors are arranged, the striking position in the circumference centered on the central sensor is calculated based on the detection result of the central sensor or the peripheral sensor, and the circle is calculated. The striking position outside the circumference is calculated based on the detection result of the central sensor. That is, the second position calculation means calculates the impact position in the circumference based on the difference in impact detection of each peripheral sensor. Here, each peripheral sensor is arranged in a region where each peripheral sensor can detect an impact within a predetermined time after the central sensor detects the impact regardless of the position in the circumference. Has been done. Therefore, it is possible to perform detection by each peripheral sensor within a predetermined time and calculate the striking position within the circumference. On the other hand, the first position calculation means calculates the impact position from the central sensor based on the initial half wave of the impact waveform detected by the central sensor. Here, each peripheral sensor is arranged in a region where the central sensor can detect the initial half wave of the striking waveform within a predetermined time after the central sensor detects the striking surface when the striking surface is hit. There is. Therefore, when the region outside the circumference is hit, the central sensor can detect the initial half wave of the hitting waveform within a predetermined time. Therefore, the detection by the central sensor can be performed within a predetermined time, and the striking position outside the circumference can be calculated.

In this way, the striking position inside the circumference in which at least three peripheral sensors are arranged is calculated based on the detection result of the central sensor or the peripheral sensor, and the striking position outside the circumference is used as the detection result of the central sensor. By calculating based on the above, it is possible to calculate the striking position inside and outside the circumference based on the detection result within a predetermined time. Therefore, even when the striking surface is formed to be large, the striking position can be calculated quickly, so that the pronunciation instruction of the striking sound is not delayed.

The shape of the striking surface may be circular, rectangular, or any shape. Further, the area for calculating the striking position based on the detection result of the central sensor and the area for calculating the striking position based on the detection result of each peripheral sensor may be arranged adjacent to each other, or a part thereof. May be arranged so as to overlap.

According to the electronic percussion instrument according to claim 3, in addition to the effect of claim 2, the following effects are exhibited. That is, each peripheral sensor is arranged by using the difference in impact detection of each peripheral sensor as a variable, providing an impact position table that stores the impact position corresponding to the variable, and calculating the impact position based on the impact position table. It is possible to quickly calculate the striking position within the circumference to be set.

According to the electronic percussion instrument according to claim 4, in addition to the effect of claim 1, the following effects are exhibited. That is, within the circumference in which the ring sensor, which is a peripheral sensor, is arranged, the striking position in the circumference centered on the center sensor is calculated based on the detection results of the central sensor and the ring sensor. The striking position outside the circumference is calculated based on the detection result of the central sensor. That is, the second position calculation means calculates the impact position in the circumference based on the difference in impact detection between the central sensor and the ring sensor. Here, the ring sensor is arranged in a region where the ring sensor can detect the impact within a predetermined time after the central sensor detects the impact regardless of the position in the circumference. There is. Therefore, the detection by the ring sensor can be performed within a predetermined time, and the striking position in the circumference can be calculated. On the other hand, the first position calculation means calculates the impact position from the central sensor based on the initial half wave of the impact waveform detected by the central sensor. Here, the ring sensor is arranged in a region where the central sensor can detect the initial half wave of the striking waveform within a predetermined time after the central sensor detects the striking surface when the striking surface is hit. .. Therefore, when the region outside the circumference is hit, the central sensor can detect the initial half wave of the hitting waveform within a predetermined time. Therefore, the detection by the central sensor can be performed within a predetermined time, and the striking position outside the circumference can be calculated.

In this way, the striking position inside the circumference where the ring sensor is arranged is calculated based on the detection results of the central sensor and the ring sensor, and the striking position outside the circumference is calculated based on the detection result of the central sensor. Therefore, the striking positions inside and outside the circumference can be calculated based on the detection result within a predetermined time. Therefore, even when the striking surface is formed to be large, the striking position can be calculated quickly, so that the pronunciation instruction of the striking sound is not delayed.

The shape of the striking surface may be circular, rectangular, or any shape. Further, the area for calculating the striking position based on the detection result of the central sensor and the area for calculating the striking position based on the detection result of the ring sensor may be arranged adjacent to each other, and a part thereof may be arranged adjacent to each other. It may be arranged so as to overlap.

According to the electronic percussion instrument according to claim 5, in addition to the effect achieved by any one of claims 1 to 4, the following effects are exhibited. That is, the striking position calculated by the first position calculating means and the striking position calculated by the second position calculating means are weighted by the third position calculating means to calculate the striking position. Therefore, it is possible to calculate the striking position more accurately.

It is an exploded perspective view of the electronic drum in one Embodiment of this invention. It is sectional drawing of an electronic drum. It is a top view schematically showing each sensor arrangement of an electronic drum. It is a block diagram which shows the electric structure of an electronic drum. (A) is a diagram schematically showing the central sensor impact position table, (b) is a diagram schematically showing the peripheral sensor impact position table, and (c) is a diagram showing the sensor value ring buffer. It is the figure which represented schematically. (A) is a voltage-time graph of a voltage waveform (output waveform from the central sensor) based on the impact at the central sensor, and (b) is detected for a certain impact on the striking surface of the electronic drum. , The voltage-time graph of the voltage waveform in the first peripheral sensor, the second peripheral sensor, and the third peripheral sensor. (A) is a flowchart of the initialization process, and (b) is a flowchart of the MIDI reception process. It is a flowchart of periodic processing. It is a flowchart of a central sensor blow processing. It is a flowchart of the peripheral sensor blow processing.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. First, the overall configuration of the electronic drum 1 will be described with reference to FIGS. 1 and 2. FIG. 1 is an exploded perspective view of the electronic drum 1 according to the embodiment of the present invention, and FIG. 2 is a cross-sectional view of the electronic drum 1. In addition, in FIGS. 1 and 2, a part of the electronic drum 1 is omitted for ease of understanding. Further, the upper side of FIGS. 1 and 2 is the upper side of the electronic drum 1, and the lower side thereof is the lower side of the electronic drum 1.

As shown in FIG. 1, the electronic drum 1 is an electronic percussion instrument simulating a drum played by using a stick or the like held by a performer. The electronic drum 1 has a shell 2 having an opening at the upper end (upper end of FIGS. 1 and 2), a head 3 covering the opening at the upper end of the shell 2, and a rim 4 connected to the outer edge of the head 3. A fixed portion 5 to which the rim 4 is attached, a frame 6 arranged to face the head 3 and arranged on the inner peripheral side of the shell 2, a control device 7 supported by the frame 6, the head 3, and the head 3. A central sensor 10 interposed between the frames 6 and arranged on the center side of the striking surface (film member 3a described later) in a plan view, and a peripheral side of the striking surface (a peripheral side of the striking surface in a plan view) than the central sensor 10. It includes a plurality of peripheral sensors (first peripheral sensor 20, second peripheral sensor 30, and third peripheral sensor 40) arranged on the outer side in the radial direction of the film member 3a.

When the performer hits the striking surface with a stick or the like (not shown), the electronic drum 1 detects the detection results from the central sensor 10 and the first peripheral sensor 20 to the third peripheral sensor 40 based on the hit. It is output to the sound source 76 (see FIG. 4), and a musical sound signal based on the detection result is generated by the sound source 76. The musical tone signal is output to the speaker 78 via the amplifier 77 (see FIG. 4), and the electronic musical tone based on the musical tone signal is emitted from the speaker 78.

The shell 2 is formed in a cylindrical shape in which both ends in the axial direction (both upper and lower ends) are open, and the outer diameter thereof is 14 inches. The outer diameter of the shell 2 is not limited to 14 inches, and the outer diameter may be set to an outer diameter of less than 14 inches or larger than 14 inches.

The head 3 includes a film member 3a formed as a striking surface and an annular frame portion 3b to which the outer edge of the film member 3a is adhered. The membrane member 3a is formed in a disk shape by a mesh-like material obtained by knitting synthetic fibers or a film-like material formed of a synthetic resin. The frame portion 3b is formed of a synthetic resin or a metal material, and the film member 3a is fixed to the frame portion 3b.

The rim 4 is an annular member that applies tension to the head 3. The rim 4 has a cylindrical frame contact portion 4a in which the lower end (the end on the fixed portion 5 side; the lower end in FIG. 2) contacts the frame portion 3b, and the upper end (frame portion) of the frame contact portion 4a. An annular elastic member 4b arranged along the entire circumference at the end opposite to the end in contact with 3b) and an annular flange protruding radially outward from the lower end of the frame contact portion 4a. A unit 4c is provided.

The frame contact portion 4a is a portion for applying the fastening force of the bolt B1, which will be described later, to the frame portion 3b to stretch the film member 3a. The inner diameter of the frame contact portion 4a is set to a dimension larger than the outer diameter of the shell 2 and smaller than the outer diameter of the frame portion 3b. The elastic member 4b is a portion to be hit by the performer, and is formed of an elastic material such as sponge, rubber, or a thermoplastic elastomer. A plurality of through holes for inserting the bolts B1 are formed in the flange portion 4c at positions corresponding to the fastened portions 5c described later.

The fixing portion 5 is a member for fixing the head 3 and the rim 4 to the shell 2. The fixing portion 5 includes an annular portion 5a fixed to the lower end of the shell 2 (lower end portion in FIG. 2) and a plurality of overhanging portions 5b formed by projecting radially outward from the annular portion 5a. , A plurality of fastened portions 5c erected upward from the plurality of overhanging portions 5b.

The annular portion 5a is formed in an annular shape by using a synthetic resin or a metal material, and the annular portion 5a and the overhanging portion 5b are integrally formed. A fastened portion 5c is fixed to the overhanging portion 5b by a screw (not shown), the fastened portion 5c is formed in a cylindrical shape by a metal material, and a female screw is formed on the inner peripheral surface thereof. The head 3 and the rim 4 are fixed to the shell 2 by screwing the bolt B1 inserted into the flange portion 4c into the fastened portion 5c.

The frame 6 is a bowl-shaped member for supporting various members such as the central sensor 10 and the first peripheral sensor 20 to the third peripheral sensor 40 on the inner peripheral side of the shell 2, and is formed of synthetic resin. The frame 6 has a bottom portion 6a arranged to face the head 3 at a predetermined distance, a side wall portion 6b erected from the outer edge of the bottom portion 6a, and a plurality of centers erected from the bottom portion 6a toward the head 3. A protrusion 6c, a connecting portion 6d connecting the plurality of central protrusions 6c to each other, a plurality of ribs 6e radially extending from the central protrusion 6c and the connecting portion 6d to the side wall portion 6b side, and the ribs 6e thereof. It is provided with a peripheral protrusion 6f integrally formed with the above.

At the upper end of the side wall portion 6b, a curved portion 6b1 that projects outward in the radial direction and curves downward is formed. The frame 6 is supported by the edge of the opening on the upper end side of the shell 2 by engaging the curved portion 6b1 along the edge of the upper end of the shell 2.

The central protrusion 6c is a portion to which the central sensor 10 is attached, and its base end is integrally formed with the bottom portion 6a, and a plurality of (three in this embodiment) are arranged along the circumferential direction of the shell 2. .. A connecting portion 6d is formed in such a manner that the plurality of central protrusions 6c are connected to each other along the circumferential direction of the shell 2, and a plurality of (12 in this embodiment) ribs are formed on the central protrusions 6c and the connecting portion 6d. 6e are connected.

The plurality of ribs 6e are formed so as to stand upright from the bottom portion 6a in a flat plate shape, and are arranged at equal intervals along the circumferential direction of the shell 2, and three of the plurality of ribs 6e are three ribs 6e. A pair of peripheral protrusions 6f are formed in each of the above.

The peripheral protrusions 6f are formed in pairs along the extending direction of the ribs 6e, and female screw holes are formed at the upper ends of the pair of peripheral protrusions 6f. The pair of peripheral protrusions 6f are arranged at three points along the circumferential direction of the shell 2, and the first peripheral sensor 20 to the third peripheral sensor 40 are respectively arranged at the peripheral protrusions 6f at these three places. .. Therefore, the first peripheral sensor 20 to the third peripheral sensor 40 are arranged at equal intervals along the circumferential direction of the shell 2.

The central sensor 10 is a sensor that detects that the striking surface has been hit, and is arranged at the center of the frame 6 in a plan view. The central sensor 10 is attached to the plate 11 attached to the tip of the central protrusion 6c, the head sensor 13 bonded to the head 3 side of the plate 11 via the double-sided tape 12, and the head 3 side of the head sensor 13. A cushion member 14 to be adhered is provided.

The plate 11 is formed in a disk shape by a metal material, and three fixed portions 11a projecting outward in the radial direction of the shell 2 are formed on the outer edge thereof. The fixed portion 11a is fixed to the tip of the central protrusion 6c by the bolt B2.

The head sensor 13 is a disk-shaped sensor that detects that the striking surface has been hit, and is composed of a piezoelectric element. The cushion member 14 is a truncated cone-shaped cushioning material formed of an elastic material such as sponge, rubber, or a thermoplastic elastomer, and its upper end is arranged in contact with the membrane member 3a.

The first peripheral sensor 20, the second peripheral sensor 30, and the third peripheral sensor 40 are sensors that detect that the striking surface has been hit, and are evenly spaced on the circumference centered on the central sensor 10 in a plan view. Arranged in.

The first peripheral sensor 20, the second peripheral sensor 30, and the third peripheral sensor 40 are configured as the same sensor except that the positions in which they are arranged are different. Therefore, the second peripheral sensor 30 and the third peripheral sensor 40 are designated by the same reference numerals as those of the first peripheral sensor 20, and detailed description thereof will be omitted.

The first peripheral sensor 20 (second peripheral sensor 30 and third peripheral sensor 40) has a plate 21 attached to the tip of a pair of first peripheral protrusions 6f and a double-sided tape 22 on the surface of the plate 21 on the head 3 side. The head sensor 23 is bonded to the head sensor 23 via the head sensor 23, and the cushion member 24 is bonded to the surface of the head sensor 23 on the head 3 side.

The plate 21 is formed in a disk shape by a metal material, and two fixed portions 21a projecting along the extending direction of the rib 6e are formed on the outer edge thereof. The fixed portion 21a is fixed to the peripheral protrusion 6f by the bolt B3.

The head sensor 23 is a disk-shaped sensor that detects that the striking surface has been hit, and is composed of a piezoelectric element. The head sensor 23 is arranged at a position closer to the striking surface than the head sensor 13 of the central sensor 10 (that is, the head sensor 23 and the film member 3a are arranged rather than the facing distance between the head sensor 13 and the film member 3a. The facing distance is formed shorter).

The cushion member 24 is a truncated cone-shaped cushioning material formed of an elastic material such as sponge, rubber, or a thermoplastic elastomer, and is formed of the same elastic material as the cushion member 14 of the central sensor 10.

That is, the first peripheral sensor 20 to the third peripheral sensor 40 are sensors having substantially the same structure as the central sensor 10 (the cushion members 14 and 24 are in contact with the film member 3a, and the cushion members 14 and 24 are abutted on the lower surface of the cushion members 14 and 24. It is configured as a sensor in which the head sensors 13 and 23 are arranged). As a result, the manufacturing cost of the electronic drum 1 can be reduced as compared with the case where the central sensor 10 and the first peripheral sensor 20 to the third peripheral sensor 40 are composed of sensors having different structures. Further, since it is not necessary to match the characteristics of the impact output of the central sensor 10 with the characteristics of the impact output of the first peripheral sensor 20 to the third peripheral sensor 40, the design can be facilitated accordingly.

Here, the thickness of the cushion member 24 (standing height from the head sensor 23) is set to be thinner (lower standing height) than the thickness of the cushion member 14 (standing height from the head sensor 13). (That is, the cushion member 14 is formed thicker than the cushion member 24). That is, the central sensor 10 is arranged at a position farther from the striking surface than the first peripheral sensor 20 to the third peripheral sensor 40.

As a result, the facing distance between the head sensor 23 and the striking surface can be shortened. Therefore, when the central portion of the striking surface (near where the cushion member 14 abuts) is hit, the hit is hit by the head of the central sensor 10. The time from the detection by the sensor 13 to the detection by the head sensor 23 of the first peripheral sensor 20 to the third peripheral sensor 40 can be shortened. That is, compared to the case where the central sensor 10 and the first peripheral sensor 20 to the third peripheral sensor 40 are provided with cushion members having the same thickness, the head sensor 23 of the first peripheral sensor 20 to the third peripheral sensor 40 detects a blow. Since the time until the signal arrives (that is, the time until the necessary information such as the signal arrival time and the peak level can be acquired) can be shortened, the delay time of the sound control by the control device 7 can be shortened.

Further, when the central portion of the striking surface is hit, the vibration of the striking (amplitude of the membrane member 3a) is larger in the peripheral portion (diameterally outside the shell 2 than the central portion in the film member 3a) as compared with the central portion of the striking surface. Therefore, the sensitivity of impact detection is reduced accordingly.

On the other hand, according to the electronic drum 1 of the present embodiment, the head sensor 23 is arranged at a position closer to the striking surface than the head sensor 13 (more than the facing distance between the head sensor 13 and the film member 3a). Since the facing distance between the head sensor 23 and the film member 3a is formed shorter), such a decrease in detection sensitivity can be compensated for.

Further, since the head sensors 13 and 23 are arranged on the back surface side of the striking surface via the cushion members 14 and 24, even if the head sensors 13 and 23 are hit directly above the head sensors 13 and 23, the hitting is performed. The impact can be absorbed by the cushion members 14, 24. Therefore, the head sensors 13 and 23 can be protected from the impact of impact and their damage can be suppressed.

Here, in order to increase the sensitivity of impact detection, it is preferable that the thicknesses of the cushion members 14 and 24 are set thin, and the head sensors 13 and 23 are arranged at positions as close as possible to the striking surface. However, if the thickness of the cushion members 14 and 24 is reduced and the head sensors 13 and 23 are brought too close to the striking surface, the striking surface is struck and hits the bottom of the head sensors 13 and 23. That is, the cushion members 14 and 24 cannot completely absorb the impact caused by the impact, and the head sensors 13 and 23 are substantially directly struck, so that the head sensors 13 and 23 are damaged.

Therefore, it is preferable that the cushion members 14 and 24 are formed to have a thickness that does not hit the head sensors 13 and 23 when the striking surface is struck. In this case, in order to set the thickness of the cushion members 14 and 24 to a thickness that does not hit the head sensors 13 and 23 at the bottom, first, the cushion members 14 and 24 are placed near the contact between the cushion members 14 and 24 and the striking surface. In the removed state, bang with a stick to measure the maximum amount of deflection of the striking surface (membrane member 3a). This amount of deflection varies depending on the tension of the striking surface, but it is measured with the striking surface stretched at the lowest tension in the assumed range (playable range).

In this case, it is preferable that the thickness of the cushion members 14 and 24 is set to a thickness of about 1.5 to 2 times the maximum amount of deflection of the cushion members 14 and 24 with respect to the maximum amount of deflection of the striking surface when the striking surface is struck. .. When the thickness of the cushion members 14 and 24 is thinner than 1.5 times the maximum amount of deflection of the striking surface at the time of banging, the cushion members 14 and 24 are likely to hit the bottom of the head sensors 13 and 23. Further, when the thickness of the cushion members 14 and 24 is thicker than twice the maximum amount of deflection of the striking surface at the time of strong striking, the thickness becomes excessive, so that the detection sensitivity of the head sensors 13 and 23 is lowered.

That is, the head sensors 13 and 23 are damaged by forming the thickness of the cushion members 14 and 24 to be about 1.5 to 2 times the maximum amount of deflection of the striking surface when the striking surface is struck. It is possible to increase the detection sensitivity while suppressing the above.

In the present embodiment, the maximum amount of deflection of the striking surface during a bang is 20 mm near the center of the striking surface (near where the cushion member 14 abuts) and 14 mm on the peripheral side (near where the cushion member 24 abuts). there were. Therefore, the thickness of the cushion member 14 was set to 35 mm (1.75 times the maximum deflection amount of 20 mm), and the thickness of the cushion member 24 was set to 25 mm (1.78 times the maximum deflection amount of 14 mm). As a result, even when the striking surface is struck hard, it is possible to prevent the head sensors 13 and 23 from hitting the bottom, and it is possible to increase the detection sensitivity of the head sensors 13 and 23.

In this way, since the striking surface is stretched by applying tension to the outer peripheral edge, the maximum amount of deflection of the striking surface at the time of striking is large near the center and smaller on the peripheral side than near the center. Become. Therefore, by forming the cushion member 14 thicker than the cushion member 24 (forming the cushion member 24 thinner than the cushion member 14) according to the maximum amount of deflection, the head sensor 23 can be made thicker than the head sensor 13. It can be arranged near the striking surface.

Therefore, by setting the thickness of the cushion members 14 and 24 according to the amount of deflection of the striking surface at the time of striking (in the present embodiment, the thickness is set to about 1.75 times the amount of deflection), the cushion members 14 and 24 are set. The arrangement position of the head sensors 13 and 23 from the striking surface (distance facing the film member 3a) can be appropriately adjusted while protecting the head sensors 13 and 23.

That is, if the heights of the cushion members 14 and 24 are set in advance according to the amount of deflection of the striking surface and the head sensors 13 and 23 are arranged on the lower surfaces of the cushion members 14 and 24, the head sensors 13 and 23 do not hit the bottom and do not hit the bottom. The head sensors 13 and 23 can be arranged at a height that can increase the detection sensitivity.

Further, when the striking surface is viewed in a plan view, one central sensor 10 arranged in the center of the striking surface and the central sensor 10 are arranged at equal intervals along the circumference centered on the circle. Since a plurality of (three in this embodiment) peripheral sensors are arranged, when the inside of the circumference in which the three peripheral sensors are arranged is hit, each of the three peripheral sensors is used. The striking position from the center of the striking surface can be detected by the detection time difference of the detected striking signal (peak, falling or rising of the voltage waveform described later). Further, the hitting signal detection waveform by the central sensor 10 can detect the hitting position from the center of the hitting surface outside the circumference in which the three peripheral sensors are arranged. Therefore, the central sensor 10 and the three peripheral sensors can appropriately detect the striking position from the center of the striking surface.

Further, the thickness of the cushion member 24 is 2 ms after the hit signal (peak described later) when the center of the hitting surface is hit is transmitted by the head sensor 23 for a predetermined time (in the present embodiment, the central sensor 10 detects the hit). ) Is set to a thickness that can be detected within. This 2 ms is the scan time by the central sensor 10 described later. The first peripheral sensor 20 to the third peripheral sensor 40 detect the peak of the impact (that is, detect the presence or absence of the impact and its intensity) by the first peripheral sensor 20 to the third peripheral sensor 40 within this scan time. From the time difference of the peaks detected in, the striking position near the center of the striking surface can be detected. Therefore, the hitting position can be detected in a shorter time than when the hitting position near the center of the hitting surface is detected by the central sensor 10 based on the initial half-wave pitch described later.

Next, the hitting position and velocity of the hitting on the electronic drum 1 are calculated according to the sensor output values of the central sensor 10 and the first peripheral sensor 20 to the third peripheral sensor 40, and the drum sound is played. Describe the program.

First, the arrangement of each sensor of the electronic drum 1 will be described with reference to FIG. FIG. 3 is a plan view schematically showing the sensor arrangement of the electronic drum 1. The electronic drum 1 has a circular striking surface when the striking surface is viewed in a plane, the central sensor 10 is arranged in the center of the striking surface, and the first peripheral sensor 20 to the third peripheral sensor 40 are arranged. , The central sensor 10 is arranged at equal intervals on the circumference of a concentric circle centered on the circle. Therefore, it is possible to appropriately detect the impact on the entire area of the striking surface formed in a circle and calculate the velocity. Further, since the amount of deformation (deflection) of the striking surface is larger in the center of the striking surface than in the peripheral portion of the striking surface, the central sensor 10 disposed in the center of the striking surface is arranged in the peripheral portion of the striking surface. Compared with the first peripheral sensor 20 to the third peripheral sensor 40, the range of the sensor output value with respect to the impact is wider, and the impact detection sensitivity is good.

It should be noted that the first peripheral sensor 20 to the third peripheral sensor 40 have the sensor output value due to the same impact during the weight processing of 2 ms from the detection of the impact by the central sensor 10 (hereinafter referred to as “scan time by the central sensor 10”). The maximum value of the absolute value (hereinafter referred to as "peak") can be detected by all of the first peripheral sensor 20 to the third peripheral sensor 40, and after the central sensor 10 detects the impact, the scan by the central sensor 10 Within the time, it is arranged at a position where the waveform of the first negative value in the impact by the sensor output value of the central sensor 10, that is, the initial half wave can be detected. Specifically, the first peripheral sensor 20 to the third peripheral sensor 40 are arranged at the position of "100" in FIG.

In the present embodiment, the striking position near the center of the striking surface is detected by the sensor output values of the first peripheral sensor 20 to the third peripheral sensor 40, and the other striking positions are detected by the sensor output value of the central sensor 10. And the sensor output values of the first peripheral sensor 20 to the third peripheral sensor 40. Although the details will be described later, the striking position by the central sensor 10 is calculated by the waveform of the first negative value in the striking by the sensor output value of the central sensor 10, that is, the magnitude of the pitch of the initial half wave. On the other hand, in the detection of the striking position of the first peripheral sensor 20 to the third peripheral sensor 40, the time difference between the peak of the first peripheral sensor 20 and the second peripheral sensor 30 and the time difference between the first peripheral sensor 20 and the third peripheral sensor 30 are detected. It is calculated from the time difference for detecting the peak from 40.

If the initial half wave in the central sensor 10 is completely detected within the scan time by the central sensor 10, and the peaks of the first peripheral sensor 20 to the third peripheral sensor 40 due to the same impact are detected, the center is detected. The striking position is calculated by a weighting calculation between the striking position calculated by the sensor 10 and the striking position by the first peripheral sensor 20 to the third peripheral sensor 40.

On the other hand, in the case of hitting near the center of the striking surface, that is, near the center sensor 10 (inner peripheral side from the position of "75" in FIG. 3), the pitch of the initial half wave detected by the center sensor 10 is large and the center. It may not be within the scan time by the sensor 10, and in that case, the accurate hitting position by the central sensor 10 cannot be calculated. That is, the region where the striking position can be calculated based on the size of the pitch of the initial half wave detected by the central sensor 10 is limited to the outer peripheral side of the vicinity of the center of the striking surface.

On the other hand, the striking positions of the first peripheral sensor 20 to the third peripheral sensor 40 are the time difference between the first peripheral sensor 20 and the second peripheral sensor 30 for detecting the peak, and the first peripheral sensor 20 and the third peripheral. It is calculated from the time difference between the sensor 40 and the peak detected. Further, as described above, the first peripheral sensor 20 to the third peripheral sensor 40 are located at positions where the initial half wave of the impact can be detected within the scan time by the central sensor 10 after the impact of the central sensor 10 is detected. Arranged.

Here, if the distance between the central sensor 10 and the first peripheral sensor 20 to the third peripheral sensor 40 is large, the central sensor 10 detects a hit, and then the first peripheral sensor 20 to the third peripheral sensor 40 change. It takes longer to detect the impact. Therefore, when the first peripheral sensor 20 to the third peripheral sensor 40 are arranged on the outer peripheral side from the position where the impact can be detected within the scan time by the central sensor 10, the first peripheral sensor 10 is placed within the scan time by the central sensor 10. The impact is not detected by the peripheral sensors 20 to the third peripheral sensor 40, and the impact position cannot be calculated. Further, when the vicinity of the center of the striking surface is hit at the arrangement positions of the first peripheral sensor 20 to the third peripheral sensor 40, the first peripheral sensor 20 to the third peripheral sensor 40 are used within the scan time by the central sensor 10. The striking position cannot be calculated, and as described above, the striking position cannot be calculated accurately by the central sensor 10. That is, within the scan time by the central sensor 10, there is a region where the striking position cannot be calculated accurately.

Therefore, in the first peripheral sensor 20 to the third peripheral sensor 40 in the present embodiment, when the striking surface is hit, the central sensor 10 detects the hit, and then the hit is made within the scan time by the central sensor 10. It is arranged at a position (position "100" in FIG. 3) that can be detected and that the initial half wave of the impact can be detected within the scan time by the central sensor 10. As a result, even if the impact is near the center of the striking surface, the striking position can be calculated by the first peripheral sensor 20 to the third peripheral sensor 40 within the scan time by the central sensor 10. Then, when it is determined that the striking position detected by the first peripheral sensor 20 to the third peripheral sensor 40 is near the center of the striking surface, the first peripheral sensor 20 to the third peripheral sensor 40 that can be calculated are used. The striking position is calculated only from the striking position. This makes it possible to obtain an accurate hitting position.

Further, the impact strength (velocity) is calculated according to the weighting calculation by the peak of the central sensor 10 and the peaks of the first peripheral sensor 20 to the third peripheral sensor 40, which are detected by the impact. Details will be described later, but if a hit is detected by the central sensor 10 and the first peripheral sensor 20 to the third peripheral sensor 40 within the scan time by the central sensor 10, the peak of the central sensor 10 and the first peripheral sensor The velocity is calculated from the peaks of the 20th to 3rd peripheral sensors 40. As a result, the velocity is calculated from the central sensor 10 having high impact sensitivity and the first peripheral sensor 20 to the third peripheral sensor 40, so that the velocity can be calculated more accurately.

On the other hand, when the central sensor 10 does not detect the impact within the weight processing of 2 ms (hereinafter referred to as "scan time by the peripheral sensor") from the detection of the impact by the first peripheral sensor 20 to the third peripheral sensor 40. , The velocity is calculated from the peaks of the first peripheral sensor 20 to the third peripheral sensor 40. As a result, even if a weak hit is made on the outer peripheral portion of the hitting surface so that the hit cannot be detected by the central sensor 10, the velocity is surely calculated, and a musical tone generation instruction is given based on the velocity.

In the present embodiment, the position at the center of the striking surface is set to "0", and the position of the outermost circumference on the striking surface is set to "127". Further, the first peripheral sensor 20 to the third peripheral sensor 40 are arranged at equal intervals at the position of "100" (that is, the first peripheral sensor 20 to the third peripheral sensor 40 are the positions of the vertices of an equilateral triangle. ). Further, the threshold value of whether or not to calculate the striking position only at the striking position detected by the first peripheral sensor 20 to the third peripheral sensor 40 is set to the position of "75".

Next, the electrical configuration of the electronic drum 1 will be described with reference to FIG. FIG. 4 is a block diagram showing an electrical configuration of the electronic drum 1. The electronic drum 1 includes a control device 7 for controlling each part of the electronic drum 1. The control device 7 has a CPU 71, a ROM 72, and a RAM 73, and each is connected via a bus line 74. Further, the central sensor 10, the first peripheral sensor 20, the second peripheral sensor 30, the third peripheral sensor 40, and the external input / output terminal 75 are connected to the bus line 74, respectively. A sound source 76 or an inspection PC 79 is connected to the external input / output terminal 75 (the drawing shows a state in which both the sound source 76 and the inspection PC 79 are connected for the sake of explanation). An amplifier 77 is connected to the sound source 76, and a speaker 78 is connected to the amplifier 77.

The CPU 71 is an arithmetic unit that controls each unit connected by the bus line 74. The ROM 72 is a non-rewritable memory, and stores the control program 72a, the central sensor hitting position table 72b, and the peripheral sensor hitting position table 72c. When the control program 72a is executed by the CPU 71, the initialization process (FIG. 7A) is executed. The central sensor impact position table 72b is a table for acquiring the impact position of the electronic drum 1 from the pitch ΔThw of the initial half wave based on the output value of the impact on the central sensor 10. Here, the pitch ΔThw of this initial half wave will be described with reference to FIG. 6A.

FIG. 6A is a voltage-time graph of a voltage waveform (output waveform from the central sensor 10) based on the impact at the central sensor 10. The vertical axis shows the voltage and the horizontal axis shows the time. The voltage waveform between the time Ts at the start of the voltage waveform based on the impact output by the central sensor 10 and the time Te at the zero crossing point of the voltage waveform immediately after that is a negative value. This is because the striking surface of the electronic drum is hit and the striking surface "deflects" in the negative direction. In the present embodiment, the negative voltage waveform output from the time Ts to Te at the start of detection of the impact is referred to as an "initial half wave". Generally, the pitch ΔThw of the initial half wave detected by the central sensor 10, that is, the time difference between the time Te and the time Ts changes according to the distance between the central sensor 10 and the striking position. Specifically, the closer the striking position is to the central sensor 10, the larger the pitch ΔThw of the initial half wave, and the farther the striking position is from the central sensor 10, the smaller the pitch ΔThw of the initial half wave. The central sensor impact position table 72b is a table obtained by calculating this relationship from the measured values. The central sensor impact position table 72b will be described with reference to FIG. 5A.

FIG. 5A is a diagram schematically showing the central sensor impact position table 72b. The central sensor striking position table 72b is a table in which the striking position calculated from the measured value is stored according to the pitch ΔThw of the initial half wave. The initial half-wave pitch ΔThw calculated from the voltage waveform based on the impact in the central sensor 10 is referred to as the initial half-wave pitch ΔThw of the central sensor impact position table 72b, and the corresponding impact position is acquired. The striking position is calculated using the acquired striking position and the striking position obtained from the first peripheral sensor 20 to the third peripheral sensor 40, which will be described later, and the performance information of the electronic drum 1 is generated based on the calculation. The numerical values of the central sensor impact position table 72b in FIG. 5A are not necessarily limited to these, and the materials and characteristics of the head 3, the central sensor 10, and the cushion member 14, the arrangement of the central sensor 10, and the arrangement of the central sensor 10. It may be appropriately set according to the height of the cushion member 14 and the like.

Return to FIG. The peripheral sensor impact position table 72c is a table for acquiring the impact position of the electronic drum 1 by the time difference of impact detection in the first peripheral sensor 20 to the third peripheral sensor 40. Here, the time difference of impact detection in the first peripheral sensor 20 to the third peripheral sensor 40 will be described with reference to FIG. 6 (b).

FIG. 6B is a voltage-time graph of voltage waveforms in the first peripheral sensor 20, the second peripheral sensor 30, and the third peripheral sensor 40, which are detected for a certain impact on the striking surface of the electronic drum 1. Is. The vertical axis represents voltage and the horizontal axis represents time. The peak time Tm1 is the time when the peak due to a certain impact is detected by the first peripheral sensor 20, and the time when the peak due to the same impact is detected by the second peripheral sensor 30 and the third peripheral sensor 40 is set. The peak time is Tm2 and the peak time is Tm3, respectively. Further, the time difference between the peak time Tm1 and the peak time Tm2 is ΔT1, and the time difference between the peak time Tm1 and the peak time Tm3 is ΔT2. Since the first peripheral sensor 20, the second peripheral sensor 30, and the third peripheral sensor 40 are arranged at equal intervals at positions "100" from the center of the striking surface (see FIG. 3), the center of the striking surface is located. When hit, the detected peak times Tm1, Tm2, and Tm3 are equal. On the other hand, when the ball is hit other than the center of the hitting surface, the detected peak times Tm1, Tm2, and Tm3 change according to the hitting position. That is, ΔT1 and ΔT2 change according to the striking position. Therefore, in the present embodiment, with the first peripheral sensor 20 as the base point of the peripheral sensor, the impact position is determined from the measured value according to the time difference ΔT1 and ΔT2 of the impact peak between the second peripheral sensor 30 and the third peripheral sensor 40. The calculated and table is the peripheral sensor impact position table 72c. The peripheral sensor impact position table 72c will be described with reference to FIG. 5 (b).

FIG. 5B is a diagram schematically showing the peripheral sensor impact position table 72c. The peripheral sensor impact position table 72c stores the impact position calculated from the measured value according to the time difference ΔT1 and ΔT2 of the impact peak between the first peripheral sensor 20, the second peripheral sensor 30, and the third peripheral sensor 40. It is a table to be done. The time difference ΔT1 and ΔT2 of the peak of the impact is referred to as the time difference ΔT1 and ΔT2 of the peripheral sensor impact position table 72c, and the corresponding impact position is acquired. As a result, the striking position by the first peripheral sensor 20 to the third peripheral sensor 40 can be obtained more quickly than in the case of calculating from the time difference ΔT1 and ΔT2 of the striking peak each time. The striking position is calculated using the acquired striking position and the striking position obtained from the central sensor 10, and the performance information of the electronic drum 1 is generated based on the calculation. It should be noted that the striking position due to the time difference ΔT1 and ΔT2 of the striking peak cannot be calculated on the outer peripheral side from the positions of the first peripheral sensor 20 to the third peripheral sensor 40. This is, for example, on the extension line connecting the time difference ΔT1 and ΔT2 of the hit peaks when hit at the position (position A) of the first peripheral sensor 20 and the position A and the center of the hitting surface, and the first peripheral sensor 20. This is because the time difference ΔT1 and ΔT2 of the peak of the impact when the impact is made at the position on the outer peripheral side of the above is the same value. Therefore, even in the peripheral sensor striking position table 72c, due to the time difference ΔT1 and ΔT2, the storage position when the peripheral sensor 20 to the third peripheral sensor 40 is on the outer peripheral side is set to the first peripheral sensor 20 to the third peripheral. The same "100" as the position of the sensor 40 is stored.

The numerical values of the peripheral sensor impact position table 72c in FIG. 5B are not necessarily limited to this, and the materials and characteristics of the head 3, the first peripheral sensor 20 to the third peripheral sensor 40, and the cushion member 24. , The first peripheral sensor 20 to the third peripheral sensor 40 are appropriately set according to the arrangement, the height of the cushion member 24, and the like.

Further, in the peripheral sensor hitting position table 72c in FIG. 5B, the hitting position is calculated with respect to the absolute value of the time difference ΔT1 and ΔT2, but the hitting position includes the positive and negative signs of the time difference ΔT1 and ΔT2. It may be calculated. That is, the calculated striking position (distance from the central sensor 10) may be different depending on the positive and negative signs of the striking peak time differences ΔT1 and ΔT2.

Return to FIG. The RAM 73 is a memory in which the CPU 71 rewritably stores various work data, flags, and the like when a program such as the control program 72a is executed. The sensor value memory 73a, the sensor value ring buffer 73b, the sensor peak value memory 73c, and the like. The central sensor scan flag 73d, the peripheral sensor scan flag 73e, the central sensor impact position gain memory 73f, the central sensor impact position memory 73g, the peripheral sensor impact position memory 73h, the impact position memory 73i, the velocity memory 73j, and the like. A test mode flag 73k and a test mode flag 73k are provided respectively.

The sensor value memory 73a is a memory that stores the sensor output values (without a unit) of the A / D converted central sensor 10 and the first peripheral sensor 20 to the third peripheral sensor 40. Although not shown, the sensor output values of the central sensor 10, the first peripheral sensor 20 to the third peripheral sensor 40 are individually stored in the sensor value memory 73a. The sensor value memory 73a is initialized with "0" when the power of the electronic drum 1 is turned on and immediately after the initialization process of FIG. 7A is executed. Then, in the periodic processing of FIG. 8, the sensor output values at the time when the periodic processing is executed in the central sensor 10, the first peripheral sensor 20 to the third peripheral sensor 40 are stored in the corresponding sensor value memory 73a. (FIG. 8, S10).

The sensor value ring buffer 73b is a buffer that stores the past 5 ms of each A / D converted sensor output value in the central sensor 10 and the first peripheral sensor 20 to the third peripheral sensor 40. The sensor value ring buffer 73b will be described with reference to FIG. 5 (c).

FIG. 5C is a diagram schematically showing the sensor value ring buffer 73b. The sensor value ring buffer 73b has a central sensor value memory 73b1, a first peripheral sensor value memory 73b2, a second peripheral sensor value memory 73b3, and a third peripheral sensor value memory 73b4, each of which is associated with each other. It will be remembered. The central sensor value memory 73b1 is a memory that stores the sensor output value (without a unit) of the central sensor 10 that has been A / D converted, and the first peripheral sensor value memory 73b2 to the third peripheral sensor value memory 73b4, respectively. , A memory that stores the A / D converted sensor output values (no unit) of the first peripheral sensor 20 to the third peripheral sensor 40, and is used when the power of the electronic drum 1 is turned on and the initialization of FIG. 7A. Immediately after the process is executed, it is initialized with "0". Then, in the periodic processing of FIG. 8, the sensor output values of the central sensor 10, the first peripheral sensor 20 to the third peripheral sensor 40 at the time when the periodic processing is executed are the corresponding central sensor value memory 73b1 and the first. 1 Peripheral sensor value memory 73b2 is added to the third peripheral sensor value memory 73b4 (FIG. 8, S10).

The sensor value ring buffer 73b is provided with a memory for storing 50 sensor output values. This is because the periodic processing of FIG. 8 described later is executed every 100 microseconds (hereinafter referred to as “μs”), and each sensor output value for the past 5 ms is stored. First, the sensor value ring buffer 73b is No. The acquired sensor output values are stored in the order of 1 to 50. And No. When each sensor output value is stored in 50, No. Sensor output values are stored in order from 1. As a result, the sensor output value for the maximum past 5 ms is stored in the sensor value ring buffer 73b. Using the value of the sensor value ring buffer 73b, the peak of each sensor output value is acquired and the pitch ΔThw of the initial half wave of the central sensor 10 is acquired.

Return to FIG. The sensor peak value memory 73c is a memory that stores the peaks (maximum absolute values) of the sensor output values of the central sensor 10 and the first peripheral sensor 20 to the third peripheral sensor 40. Although not shown, the sensor peak value memory 73c individually stores the peaks of the sensor output values of the central sensor 10, the first peripheral sensor 20 to the third peripheral sensor 40, respectively. The value of the sensor peak value memory 73c is initialized to "0" when the power of the electronic drum 1 is turned on and immediately after the initialization process of FIG. 7A is executed. Then, in the periodic processing of FIG. 8, when a hit is detected by the central sensor 10, the first peripheral sensor 20 to the third peripheral sensor 40, the central sensor 10, the first peripheral sensor 20 to the third from the sensor value ring buffer 73b. The peak of the sensor output value in the peripheral sensor 40 is stored in the sensor peak value memory 73c (FIGS. 8, S16, S19). After that, the value of the sensor value memory 73a in the central sensor 10, the first peripheral sensor 20 to the third peripheral sensor 40 is compared with the value of the corresponding sensor peak value memory 73c, and the larger one becomes the sensor peak value memory 73c. It is stored (FIGS. 8, S21, S25). Velocity due to impact is calculated by a weighting operation based on the values of the sensor peak value memory 73c of the central sensor 10, the first peripheral sensor 20 to the third peripheral sensor 40 (FIGS. 9, S33, 10, S53).

The central sensor scan flag 73d is a flag indicating that the scan time by the central sensor 10, which is a weight process of 2 ms, is in progress. The central sensor scan flag 73d is set to off, which indicates that the scan time by the central sensor 10 is not in progress when the power of the electronic drum 1 is turned on and immediately after the initialization process of FIG. 7A is executed. Then, when it is determined that a hit is detected in the central sensor 10 in the periodic processing of FIG. 8, the central sensor scan flag 73d is set to ON (FIGS. 8 and S17), and in the central sensor impact processing of FIG. 9, the center is set. When the scan time of the sensor 10 ends, the central sensor scan flag 73d is set to off (FIGS. 9, S31).

The peripheral sensor scan flag 73e is a flag indicating that the scan time by the peripheral sensor, which is a weight process of 2 ms, is in progress. The peripheral sensor scan flag 73e is set to off, which indicates that the scan time by the peripheral sensor is not in progress when the power of the electronic drum 1 is turned on and immediately after the initialization process of FIG. 7A is executed. Then, when it is determined that a hit is detected in any of the first peripheral sensor 20 to the third peripheral sensor 40 in the periodic processing of FIG. 8, the peripheral sensor scan flag 73e is set to ON (FIGS. 8, S20). In the peripheral sensor impact processing of FIG. 10, when the scan time of the first peripheral sensor 20 to the third peripheral sensor 40 is completed, the peripheral sensor scan flag 73e is set to off (FIGS. 10, S51). Further, when the peripheral sensor scan flag 73e is on and the impact by the central sensor 10 is detected, the peripheral sensor scan flag 73e is set to off (FIGS. 8, S24). The details will be described later, but if a hit by the central sensor 10 is detected within the scan time by the peripheral sensor, the scan time by the peripheral sensor is stopped, the scan time by the central sensor 10 is performed again, and the central sensor 10 is used. This is because the striking position and velocity are calculated by the central sensor 10 and the first peripheral sensor 20 to the third peripheral sensor 40 after the scan time according to the above.

The central sensor striking position gain memory 73f is a memory used for calculating the striking position and storing a weighting coefficient with respect to the striking position by the central sensor 10. The central sensor striking position gain memory 73f is initialized with "0" when the power of the electronic drum 1 is turned on and immediately after the initialization process of FIG. 7A is executed. In the central sensor striking position gain memory 73f in the present embodiment, the ratio (value of 0 or more and 1 or less) indicating how much the striking position by the central sensor 10 is considered for the calculation of the striking position is a weighting coefficient. Is remembered as. On the other hand, the value obtained by subtracting the value of the central sensor striking position gain memory 73f from 1 indicates how much the striking position by the first peripheral sensor 20 to the third peripheral sensor 40 is taken into consideration in the calculation of the striking position. It is a ratio (weight coefficient).

That is, in the central sensor striking process of FIG. 9, the threshold value of whether or not the striking position by the first peripheral sensor 20 to the third peripheral sensor 40 is performed only by the striking position detected by the first peripheral sensor 20 to the third peripheral sensor 40. If it is "75" or more, "0.5" is set in the central sensor striking position gain memory 73f, and if the striking position by the first peripheral sensor 20 to the third peripheral sensor 40 is smaller than "75", it is "75". 0 ”is set (FIGS. 9, S38, S39). Then, the value of the central sensor striking position gain memory 73f, the striking position by the central sensor 10 (that is, the value of the central sensor striking position memory 73g described later), and the striking position by the first peripheral sensor 20 to the third peripheral sensor 40 (that is, the value of the central sensor striking position memory 73g). That is, the striking position is calculated by the weighting calculation based on the peripheral sensor striking position memory 73h (value in FIG. 9, S40).

The central sensor striking position memory 73g is a memory that stores the striking position acquired by the central sensor 10, and is “0” when the electronic drum 1 is turned on and immediately after the initialization process of FIG. 7A is executed. It is initialized with. Then, in the central sensor impact processing of FIG. 9, the pitch ΔThw of the initial half wave of the central sensor 10 calculated from the sensor value ring buffer 73b is referred to by the central sensor impact position table 72b, and the acquired impact position is the center. It is stored in the sensor impact position memory 73g (FIGS. 9, S34).

The peripheral sensor striking position memory 73h is a memory that stores the striking position acquired by the first peripheral sensor 20 to the third peripheral sensor 40, and is used when the electronic drum 1 is turned on and the initialization process of FIG. 7A is performed. Immediately after it is executed, it is initialized with "0". Then, the peripheral sensor determines the peak time difference ΔT1 between the first peripheral sensor 20 and the second peripheral sensor 30 and the peak time difference ΔT2 between the first peripheral sensor 20 and the third peripheral sensor 40 calculated from the sensor value ring buffer 73b. The striking position referred to by the striking position table 72c and acquired is stored in the peripheral sensor striking position memory 73h (FIGS. 9, S36).

The striking position memory 73i is a memory that stores the striking position calculated based on the detection result of the striking of the electronic drum 1 on the striking surface, and is performed when the power of the electronic drum 1 is turned on and the initialization process of FIG. 7A. Immediately after it is executed, it is initialized with "0". When the central sensor 10 detects an impact, the impact position is calculated from the impact position by the central sensor 10 and the impact position by the first peripheral sensor 20 to the third peripheral sensor 40 after the scan time by the central sensor 10 ( FIG. 9, S40).

On the other hand, if the first peripheral sensor 20 to the third peripheral sensor 40 detect the impact and the central sensor 10 does not detect the impact within the scan time by the peripheral sensor, "100" is stored in the impact position memory 73i. To. That is, when the central sensor 10 does not detect the impact, such as when the outer peripheral portion of the striking surface is weakly impacted, while the first peripheral sensor 20 to the third peripheral sensor 40 detect the impact, the first peripheral sensor Assuming that the sensor 40 is hit at the positions of the 20th to the third peripheral sensors 40 (FIGS. 10, S54), an instruction to generate a musical tone is given based on the hitting position. As a result, it is possible to give an instruction to generate a musical tone by a weak hit on the outer peripheral portion of the striking surface, and the instruction to generate a musical tone is not delayed. When the central sensor 10 does not detect a hit, the value stored in the hit position memory 73i is not necessarily limited to "100", and any value in the range of "100" to "127" can be used. It may be remembered.

The velocity memory 73j is a memory that stores the velocity (impact strength) calculated based on the detection result of the impact on the striking surface of the electronic drum 1, and is the memory when the power of the electronic drum 1 is turned on and the initialization of FIG. 7A. Immediately after the process is executed, it is initialized with "0". In the central sensor impact processing of FIG. 9, it was calculated by weighting the peaks of the sensor output values of the central sensor 10 and the first peripheral sensor 20 to the third peripheral sensor 40 stored in the sensor peak value memory 73c. The velocity is stored in the velocity memory 73j (FIGS. 9, S33). Further, in the peripheral sensor impact processing of FIG. 10, the velocity calculated by weighting the peaks of the sensor output values of the first peripheral sensor 20 to the third peripheral sensor 40 stored in the sensor peak value memory 73c is the velocity. It is stored in the memory 73j (FIG. 10, S53). Then, an instruction to generate a musical tone according to the value of the velocity memory 73j and the value of the striking position memory 73i is given to the sound source 76 described later (FIGS. 9, S41, 10, S55).

The test mode flag 73k is a flag indicating that the electronic drum 1 is in the test mode, and is not in the test mode when the power of the electronic drum 1 is turned on and immediately after the initialization process of FIG. 7A is executed. Set to off to indicate that. In the MIDI reception process of FIG. 7 (b), the test mode flag 73k is set to ON when a message for switching to the test mode is received (FIGS. 7 (b) and S3). In the present embodiment, when the electronic drum 1 in the test mode detects a hit by the central sensor 10 or the first peripheral sensor 20 to the third peripheral sensor 40, the central sensor 10 and the first peripheral sensor 20 to the third peripheral sensor 20 to th after 320 ms. 3 The sensor output value of the peripheral sensor 40, that is, the value of the sensor peak value memory 73c included in the MIDI system exclusive (hereinafter referred to as “SysEx”) message is transmitted via the external input / output terminal 75 described later. do. The inspection PC 79, which will be described later, connected to the external input / output terminal 75 analyzes the received SysEx message, and from the sensor output values of the central sensor 10 and the first peripheral sensor 20 to the third peripheral sensor 40 contained therein, Determine if each sensor is operating normally.

The external input / output terminal 75 is an interface for transmitting / receiving data between the electronic drum 1 and the sound source 76, the inspection PC 79, which will be described later, or another computer. The music sound generation instruction generated by the electronic drum 1 is transmitted to the sound source 76 via the external input / output terminal 75, and MIDI SysEx including the value of the sensor peak value memory 73c via the external input / output terminal 75. Send the message to the inspection PC79. Also, a MIDI SysEx message is received from the inspection PC 79.

The sound source 76 is a device that controls the tone color and various effects of a musical tone (striking sound) according to an instruction from the CPU 71. The sound source 76 has a built-in DSP (Digital Signal Processor) 76a that performs arithmetic processing such as a waveform data filter and an effect. The musical tone processed by the sound source 76 is output as an analog musical tone signal.

The amplifier 77 is a device that amplifies the analog musical tone signal output by the sound source 76, and outputs the amplified analog musical tone signal to the speaker 78. The speaker 78 sounds (outputs) an analog musical tone signal amplified by the amplifier 77 as a musical tone.

The inspection PC 79 is a computer for analyzing the sensor output values of the central sensor 10 and the first peripheral sensor 20 to the third peripheral sensor 40 included in the MIDI SysEx message received from the electronic drum 1 in the test mode. The inspection PC 79 transmits a MIDI SysEx message including a test mode switching message to the electronic drum 1 via the external input / output terminal 75. When the electronic drum 1 receives the test mode switching message, the electronic drum 1 shifts to the test mode, and when the electronic drum 1 detects a hit, the value of the sensor peak value memory 73c is included in the MIDI SysEx message after 320 ms. , Send to inspection PC79. Then, the inspection PC 79 analyzes the MIDI SysEx message including the value of the received sensor peak value memory 73c on the inspection jig application executed by the inspection PC 79, and analyzes the central sensor 10 and the first peripheral sensors 20 to the third. It is determined whether the peripheral sensor 40 is operating normally.

The initialization process executed by the CPU 71 of the electronic drum 1 will be described with reference to FIG. 7A. FIG. 7A is a flowchart of the initialization process. The initialization process is executed immediately after the power of the electronic drum 1 is turned on, and each memory value and flag on the RAM 73 are initialized (S1).

Next, the MIDI reception process executed by the CPU 71 of the electronic drum 1 will be described with reference to FIG. 7 (b). The MIDI reception process is executed by an interrupt process performed when the MIDI data is received via the external input / output terminal 75.

FIG. 7B is a flowchart of MIDI reception processing. In the MIDI reception process, first, the received MIDI data is analyzed, and it is confirmed whether the result is a switching message to the test mode (S2). If the received MIDI data is a message for switching to the test mode (S2: Yes), the test mode flag 73k is set to ON (S3). On the other hand, if the received MIDI data is not a message for switching to the test mode (S2: No), the process of S3 is skipped. After the processing of S2 and S3, the MIDI reception processing is terminated. As a result, when the MIDI data received from the inspection PC 79 is a message for switching to the test mode, the electronic drum 1 shifts to the test mode. Then, when the electronic drum 1 detects a hit, the electronic drum 1 transmits the value of the sensor peak value memory 73c included in the MIDI SysEx message to the inspection PC 79 after 320 ms. The test mode flag 73k set to ON is kept on until the power of the electronic drum 1 is turned off, and the process of S1 in FIG. 7A immediately after the next power-on of the electronic drum 1 is performed. Is set to off.

Next, with reference to FIGS. 8 to 10, periodic processing executed by the CPU 71 of the electronic drum 1 will be described. In the periodic processing, the sensor output values of the central sensor 10 and the first peripheral sensor 20 to the third peripheral sensor 40 at the time when the periodic processing is executed are acquired, and when the scan time has elapsed, the striking position and velocity are determined. The central sensor striking process (FIG. 9) or the peripheral sensor striking process (FIG. 10), which is calculated and instructed to generate a musical tone, is executed. The periodic processing is repeatedly executed every 100 μs by the interval interrupt process every 100 μs.

FIG. 8 is a flowchart of periodic processing. In the periodic processing, first, the sensor output values of the central sensor 10 and the first peripheral sensor 20 to the third peripheral sensor 40 are acquired, stored in the sensor value memory 73a, and added to the sensor value ring buffer 73b (S10). To the sensor value ring buffer 73b, first, No. 1 in FIG. 5 (c). 1 is the storage position of the sensor output value. After that, No. 2, No. The storage position moves in ascending order to 3 ..., and the sensor output value is stored in that area. No. If it is stored up to 50, No. It is stored in 1. Since the periodic processing is executed every 100 μs, the value of the sensor value memory 73a and the value of the sensor value ring buffer 73b are also updated every 100 μs.

After the processing of S10, it is confirmed whether the central sensor scan flag 73d is on (S11). When the central sensor scan flag 73d is off (S11: No), that is, when the scan time by the central sensor 10 is not in progress, it is confirmed whether the peripheral sensor scan flag 73e is on (S12).

When the peripheral sensor scan flag 73e is off (S12: No), that is, when the scan time by the peripheral sensor is not in progress, it is confirmed whether the central sensor 10 has detected a hit (S13). The detection of the impact by the central sensor 10 is determined by whether or not a falling edge (or rising edge) is detected in the voltage waveform by the sensor value ring buffer 73b of the central sensor 10.

When the central sensor 10 detects a hit (S13: Yes), 0 is set in the sensor peak value memory 73c of the central sensor 10 and the first peripheral sensor 20 to the third peripheral sensor 40 (S15). Since the sensor peak value memory 73c may store the peak of the sensor output value stored before the previous time, the value of the sensor peak value memory 73c is set to "0" when the central sensor 10 detects a hit. Initialize with.

After the processing of S15, the peak of the sensor peak value memory 73c of the central sensor 10 and the first peripheral sensor 20 to the third peripheral sensor 40 is acquired from the value of the sensor value ring buffer 73b, and the sensor peak value of the corresponding sensor is acquired. It is saved in the memory 73c (S16).

After the processing of S16, the central sensor scan flag 73d is set to ON, and the time counting of the scan time is started from 0 (S17). After that, the scan time is timed each time the periodic process is executed. As a result, the timing of the "scan time by the central sensor 10" is started.

If the central sensor 10 does not detect a hit in the process of S13 (S13: No), it is confirmed whether any of the first peripheral sensor 20 to the third peripheral sensor 40 detects the hit (S14). The impact detection by the first peripheral sensor 20 to the third peripheral sensor 40 also detects the falling edge (or rising edge) in the voltage waveform by the sensor value ring buffer 73b of any one of the first peripheral sensor 20 to the third peripheral sensor 40. It is judged by whether or not it was done.

When any one of the first peripheral sensor 20 to the third peripheral sensor 40 detects a hit (S14: Yes), the sensor peak value memory 73c of the central sensor 10 and the first peripheral sensor 20 to the third peripheral sensor 40 0 is set (S18), the peak of the sensor peak value memory 73c of the central sensor 10 and the first peripheral sensor 20 to the third peripheral sensor 40 is acquired from the value of the sensor value ring buffer 73b, and the sensor of the corresponding sensor is obtained. It is saved in the peak value memory 73c (S19).

After the processing of S19, the peripheral sensor scan flag 73e is set to ON, and the time counting of the scan time is started from 0 (S20). After that, the scan time is timed each time the periodic process is executed. As a result, the timing of the "scan time by the peripheral sensor" is started.

At the start of the scan time by the central sensor 10 or the scan time by the peripheral sensors, the peak of each sensor stored in the sensor value ring buffer 73b in the latest 5 ms is acquired and stored in the sensor peak value memory 73c. This means that even if the central sensor 10 or the first peripheral sensor 20 to the third peripheral sensor 40 detects a hit, any one of the first peripheral sensor 20 to the third peripheral sensor 40 or the central sensor 10 first hits. This is because there is a possibility that the peak in the voltage waveform due to the impact is stored in the sensor peak value memory 73c. First, at the start of each scan time, a peak is searched from the value of the sensor value ring buffer 73b, and the peak is stored in the sensor peak value memory 73c. After that, in the processes of S21 and S25 described later, each time the periodic process is executed during each scan time, the sensor output value at the time when the periodic process is executed is stored as the value of the sensor value memory 73a. , The value of the sensor peak value memory 73c is compared, and the value having a large maximum absolute value is stored in the sensor peak value memory 73c. As a result, the peak of the sensor output value before and after the scan time by the central sensor 10 is stored in the sensor peak value memory 73c.

On the other hand, if none of the first peripheral sensors 20 to the third peripheral sensor 40 detects an impact (S14: No), the processes of S18 to S20 are skipped.

In the process of S11, when the central sensor scan flag 73d is on (S11: Yes), the absolute value of the sensor peak value memory 73c of the central sensor 10 and the first peripheral sensor 20 to the third peripheral sensor 40 corresponds to the corresponding value. The absolute value of the sensor value memory 73a of the sensor is compared, and each large value is stored in the sensor peak value memory 73c (S21). The sensor peak value memory 73c stores the peak value in the sensor value ring buffer 73b of each sensor in the process of S16 immediately after the impact by the central sensor 10 is detected (S13: Yes). Since the peak value may be detected from each sensor even at the timing after this, the central sensor scan flag 73d is turned on, that is, during the scan time by the central sensor 10, it is acquired from each sensor at that time. The absolute value of the sensor output value (that is, the value of the sensor value memory 73a) is compared with the absolute value of the value of the sensor peak value memory 73c of the corresponding sensor, and the larger value is stored in the sensor peak value memory 73c. Will be done. After the processing of S21, the central sensor impact processing is executed (S22). The central sensor impact processing will be described later with reference to FIG.

In the process of S12, when the peripheral sensor scan flag 73e is on (S12: Yes), it is confirmed whether the central sensor 10 has detected a hit (S23). The method of confirming whether the central sensor 10 has detected a hit is the same as the process of S13. When the central sensor 10 detects a hit (S23: Yes), the peripheral sensor scan flag 73e is set to off, the time counting of the scan time is stopped (S24), and the processing after S16 is performed. That is, when a hit by the central sensor 10 is detected during the scan time by the peripheral sensor, the scan time by the central sensor 10 is started.

That is, since the amount of deformation (deflection) of the striking surface is larger in the center of the striking surface than in the peripheral portion of the striking surface, the central sensor 10 disposed in the center of the striking surface is disposed in the peripheral portion of the striking surface. Compared with the first peripheral sensor 20 to the third peripheral sensor 40, the range of the sensor output value with respect to the impact is wider, and the impact detection sensitivity is good. Therefore, even if the first peripheral sensor 20 to the third peripheral sensor 40 detect the impact before the central sensor 10, if the central sensor 10 detects the impact within the scan time by the peripheral sensor, the scan time by the central sensor 10 After that, the velocity is calculated based on the impact detection results of the central sensor 10 and the first peripheral sensor 20 to the third peripheral sensor 40. Therefore, even when the first peripheral sensor 20 to the third peripheral sensor 40 detect the impact before the central sensor 10, the first peripheral sensor 20 to the third peripheral sensor 40 detect the impact after the central sensor 10. In this case as well, the velocity can be calculated using the detection result of the central sensor 10 having good sensitivity.

In this case, the instruction to generate the musical tone is delayed by the time from the detection of the impact of the first peripheral sensor 20 to the impact of the third peripheral sensor 40 to the detection of the impact of the central sensor 10. However, since the period for determining whether or not the hit of the central sensor 10 is detected is within the scan time by the peripheral sensor from the detection of the hit of the first peripheral sensor 20 to the third peripheral sensor 40, the musical sound is generated. The delay time of the instruction can be stopped within the scan time (that is, 2 ms) by the peripheral sensor. That is, by adjusting the time counting time of the scan time by the peripheral sensor, the delay time of the musical tone generation instruction can be kept within the range of the design value.

When the central sensor 10 does not detect a blow in the processing of S23 (S23: No), the absolute value of the sensor peak value memory 73c of the central sensor 10 and the first peripheral sensor 20 to the third peripheral sensor 40 is used. , The absolute value of the sensor value memory 73a of the corresponding sensor is compared, and each large value is stored in the sensor peak value memory 73c (S25). After the processing of S25, the peripheral sensor impact processing is executed (S26). The peripheral sensor impact processing will be described later with reference to FIG. After the processing of S14, S17, S20, S22, S26, the periodic processing ends.

Next, with reference to FIG. 9, the central sensor impact processing (FIGS. 8, S22) executed during the scan time by the central sensor 10 will be described. In the central sensor impact processing, the impact position and velocity are calculated from the values of the sensor peak value memory 73c of the central sensor 10 and the first peripheral sensor 20 to the third peripheral sensor 40 and the values of the sensor value ring buffer 73b, and the impact is calculated. The sound source 76 is instructed to generate a musical sound according to the position and velocity, and the musical sound of the electronic drum 1 is generated.

First, the central sensor striking process confirms whether the scan time is 2 ms or more (S30). The scan time by the central sensor 10 in 2 ms after the central sensor 10 detects the impact is during the so-called "weight processing" in which the output value of each sensor due to the impact is monitored and the impact position and velocity due to the impact are not calculated. Therefore, check whether the scan time has passed.

When the scan time is 2 ms or more (S30: Yes), the scan time by the central sensor 10 has ended, so the central sensor scan flag 73d indicating that the scan time by the central sensor 10 is in progress is set to OFF. Stop timing the scan time (S31).

ここで、gain_c，gain_s1，gain_s2，gain_s3はゲイン定数であり、それぞれ、「０．３」，「０．２」，「０．２」，「０．２」である。また、gain_Mix_vは、ユーザによって設定される値であり、電子ドラム１の入力装置（図示せず）によって設定される値である。数式１で算出された、ベロシティＶｌがベロシティメモリ７３ｊに記憶される。なお、各ゲイン定数は、必ずしも上述した値に限られるものではなく、打面の大きさや素材、中央センサ１０や第１周辺センサ２０〜第３周辺センサ４０の感度等に応じて、適宜設定してもよい。 After the processing of S31, it is confirmed whether or not the test mode flag 73k is off (S32). That is, it is confirmed whether the electronic drum 1 is in the test mode. When the test mode flag 73k is off (S32: Yes), the value of the sensor peak value memory 73c of the central sensor 10 and the value of the sensor peak value memory 73c of the first peripheral sensor 20 to the third peripheral sensor 40 are weighted. The calculation is performed and the result is stored in the velocity memory 73j (S33). That is, the velocity due to the impact (impact intensity) in the central sensor impact processing is calculated by the weighting calculation of the peak value of each sensor. Assuming that the value of the sensor peak value memory 73c of the central sensor 10 is peak_c and the value of the sensor peak value memory 73c of the first peripheral sensor 20 to the third peripheral sensor 40 is peak_s1, peak_s2, peak_s3, respectively, the velocity Vl is given by Equation 1. It is calculated by the weighting operation of.

Here, gain_c, gain_s1, gain_s2, and gain_s3 are gain constants, which are "0.3", "0.2", "0.2", and "0.2", respectively. Further, gain_Mix_v is a value set by the user and is a value set by the input device (not shown) of the electronic drum 1. The velocity Vl calculated by the formula 1 is stored in the velocity memory 73j. It should be noted that each gain constant is not necessarily limited to the above-mentioned value, and is appropriately set according to the size and material of the striking surface, the sensitivity of the central sensor 10 and the first peripheral sensor 20 to the third peripheral sensor 40, and the like. You may.

After the processing of S33, the initial half wave due to the impact of the central sensor 10 is acquired from the value of the sensor value ring buffer 73b, and the pitch ΔThw of the initial half wave refers to the central sensor impact position table 72b and the corresponding impact. The position is stored in the central sensor striking position memory 73 g (S34). Specifically, the value of the central sensor value memory 73b1 of the sensor value ring buffer 73b is referred to, and the position where the minimum value is obtained is acquired. First, the value of the central sensor value memory 73b1 of the sensor value ring buffer 73b is referred to in the retroactive direction from that position, and the position where the value becomes 0 is acquired. That is, this time point is the time Ts in FIG. 6A.

Then, from the value of the central sensor value memory 73b1 of the sensor value ring buffer 73b, the value of the central sensor value memory 73b1 of the sensor value ring buffer 73b is referred to in the downward direction, and the position where the value becomes 0 is acquired. That is, this time point is the time Te in FIG. 6A. As a result of referring to the value of the central sensor value memory 73b1 of the sensor value ring buffer 73b in the downward direction of time, if there is no position to be 0, the current position of the sensor value ring buffer 73b is set as the time Te. This is a case where the vicinity of the center of the striking surface of the electronic drum 1 is hit, and all the initial half waves due to the vibration cannot be detected within the scan time by the central sensor 10. The correspondence in this case will be described later in the processes of S37 to S39.

The time difference between the time Ts and the time Te, that is, the value of the pitch ΔThw of the initial half wave, refers to the central sensor impact position table 72b, and stores the corresponding impact position in the central sensor impact position memory 73g.

After the processing of S34, the hit detection time of the first peripheral sensor 20 to the third peripheral sensor 40 is acquired from the value of the sensor value ring buffer 73b (S35). Specifically, the values of the first peripheral sensor value memory 73b2, the second peripheral sensor value memory 73b3, and the third peripheral sensor value memory 73b4 of the sensor value ring buffer 73b are referred to, respectively, and the position where the minimum value is obtained (that is, the figure). 5 (c) "No.") is acquired. Then, by multiplying the difference between that position and the storage position of the current sensor value ring buffer 73b (that is, the storage position stored in S10 of FIG. 8) by 100 μs, the time at which the minimum value is obtained, that is, FIG. 6 The peak times Tm1, Tm2, and Tm3 in (b) are calculated, respectively.

Then, the time difference ΔT1 between the peak times Tm1 and Tm2 and the time difference ΔT2 between the peak times Tm1 and Tm3 refer to the peripheral sensor impact position table 72c, and the corresponding impact position is stored in the peripheral sensor impact position memory 73h. (S36).

After the processing of S36, it is confirmed whether the value of the peripheral sensor impact position memory 73h is 75 or more (S37). When the value of the peripheral sensor striking position memory 73h is 75 or more (S37: Yes), “0.5” is set in the central sensor striking position gain memory 73f (S38). On the other hand, when the value of the peripheral sensor striking position memory 73h is smaller than 75 (S37: No), “0” is set in the central sensor striking position gain memory 73f (S39). As described above, when the electronic drum 1 is hit near the center of the striking surface, the central sensor 10 may not be able to detect the initial half wave within the scan time due to the large vibration near the center of the striking surface. .. The striking position by the central sensor 10 is acquired from the central sensor striking position table 72b by the pitch ΔThw of the initial half wave. Therefore, if the initial half wave cannot be completely detected, the striking position cannot be acquired.

However, even in this case, the striking position is accurately acquired due to the time difference of the striking detection of the first peripheral sensor 20 to the third peripheral sensor 40 described above in the process of S35. This is because the impact detection by the first peripheral sensor 20 to the third peripheral sensor 40 is faster than the complete detection of the pitch ΔThw of the initial half wave by the central sensor 10. Therefore, when the striking position (that is, the value of the peripheral sensor striking position memory 73h) due to the time difference of the striking detection of the first peripheral sensor 20 to the third peripheral sensor 40 is smaller than "75", that is, the striking surface of the electronic drum 1. When it is close to the center of the center sensor, “0” is set in the center sensor striking position gain memory 73f, and the striking position by the central sensor 10 is not taken into consideration in the calculation of the striking position by the weighting calculation described later. As a result, if the striking is performed near the center of the striking surface of the electronic drum 1 and there is a possibility that the striking position may not be accurately acquired by the central sensor 10, the striking position is acquired by the first peripheral sensor 20 to the third peripheral sensor 40. Since the striking position is calculated only by the striking position, an accurate striking position can be obtained.

On the other hand, when the value of the peripheral sensor striking position memory 73h is "75" or more, that is, when the value is far from the center of the striking surface of the electronic drum 1, the central sensor striking position gain memory 73f is "0.5". Is set, and the striking position by the central sensor 10 is taken into consideration in the calculation of the striking position by the weighting calculation described later. The striking position by the central sensor 10 is calculated accurately if the position is "75" or more, and the striking position by the first peripheral sensor 20 to the third peripheral sensor 40 is calculated if the position is less than "100". , The hitting position is calculated accurately. Therefore, by calculating the striking position by combining the striking position by the central sensor 10 and the striking position by the first peripheral sensor 20 to the third peripheral sensor 40, a more accurate striking position can be obtained. In this case, the value set in the central sensor striking position gain memory 73f is not necessarily limited to "0.5", and may be appropriately set according to the size of the striking surface, the material, and the like.

ここで、pre_gain_cは中央センサ打撃位置ゲインメモリ７３ｆの値である。また、1-pre_gain_cは第１周辺センサ２０〜第３周辺センサ４０による打撃位置への重み係数である。即ちpre_gain_cは、打撃位置の算出において、中央センサ１０による打撃位置がどの程度考慮されるかを示す割合なので、1-pre_gain_cは、打撃位置の算出において、第１周辺センサ２０〜第３周辺センサ４０による打撃位置が考慮される割合を示す割合（重み係数）である。また、gain_Mix_pは、ユーザによって設定される値であり、電子ドラム１の入力装置（図示せず）によって設定される値である。数式２で算出された、打撃位置positionが打撃位置メモリ７３ｉに記憶される。Ｓ４０の処理の後、打撃位置メモリ７３ｉの値およびベロシティメモリ７３ｊの値に応じた楽音の生成指示を音源７６に出力する（Ｓ４１）。 After the processing of S38 and S39, the striking position is calculated by weighting the value of the central sensor striking position memory 73g, the value of the peripheral sensor striking position memory 73h, and the value of the central sensor striking position gain memory 73f, and striking. It is saved in the position memory 73i (S40). Assuming that the value of the central sensor striking position memory 73g is position_center and the value of the peripheral sensor striking position memory 73h is position_sub, the striking position position is calculated by the weighting operation of Equation 2.

Here, pre_gain_c is the value of the central sensor striking position gain memory 73f. Further, 1-pre_gain_c is a weighting coefficient for the striking position by the first peripheral sensor 20 to the third peripheral sensor 40. That is, since pre_gain_c is a ratio indicating how much the striking position by the central sensor 10 is taken into consideration in the calculation of the striking position, 1-pre_gain_c is the first peripheral sensor 20 to the third peripheral sensor 40 in the calculation of the striking position. It is a ratio (weighting coefficient) indicating the ratio in which the striking position is taken into consideration. Further, gain_Mix_p is a value set by the user and is a value set by an input device (not shown) of the electronic drum 1. The striking position position calculated by the formula 2 is stored in the striking position memory 73i. After the processing of S40, a musical tone generation instruction corresponding to the value of the striking position memory 73i and the value of the velocity memory 73j is output to the sound source 76 (S41).

In the process of S32, when the test mode flag 73k is on (S32: No), the values of the sensor peak value memory 73c of the central sensor 10 and the first peripheral sensor 20 to the third peripheral sensor 40 are included in the MIDI SysEx message. Is output (S42). If the scan time is smaller than 2 ms in the process of S30, the process of S31 to S42 is skipped. Then, after the processing of S30, S41, and S42, the central sensor impact processing is completed, and the process returns to the periodic processing of FIG.

Next, referring to FIG. 10, the peripheral sensor impact processing (FIG. 8) is executed when the central sensor 10 does not detect the impact during the scan time by the peripheral sensor, such as when the outer peripheral side of the impact surface is weakly impacted. , S26) will be described. In the peripheral sensor impact processing, the impact position and velocity are calculated from the values of the sensor value ring buffer 73b of the first peripheral sensor 20 to the third peripheral sensor 40. The striking position in this case is "100 (fixed value)" (see FIG. 3). Then, the sound source 76 is instructed to generate a musical tone according to the striking position and velocity, and the musical tone of the electronic drum 1 is generated.

First, the peripheral sensor impact processing confirms whether the scan time is 2 ms or more (S50). The scan time by the peripheral sensor in 2 ms after the first peripheral sensor 20 to the third peripheral sensor 40 detects the impact monitors the output value of each sensor due to the impact and does not calculate the impact position and velocity due to the impact. Since the so-called "weight processing" is in progress, it is confirmed whether the scan time has elapsed.

When the scan time is 2 ms or more (S50: Yes), the scan time by the first peripheral sensor 20 to the third peripheral sensor 40 has elapsed, so that the first peripheral sensor 20 to the third peripheral sensor 40 are in the scan time. The peripheral sensor scan flag 73e indicating that the sensor is set to off is set to off, and the time counting of the scan time is stopped (S51).

ここで、gain_s1，gain_s2，gain_s3はゲイン定数であり、それぞれ、「０．２」，「０．２」，「０．２」である。なお、各ゲイン定数は、必ずしも上述した値に限られるものではなく、打面の大きさや素材、第１周辺センサ２０〜第３周辺センサ４０の検出感度等に応じて、適宜設定してもよい。また、gain_Mix_vは、ユーザによって設定される値であり、電子ドラム１の入力装置（図示せず）によって設定される値である。なお、gain_Mix_vは、数式１におけるgain_Mix_vと同じ値に限られるものではなく、別の値が設定されてもよい。 After the processing of S51, it is confirmed whether or not the test mode flag 73k is off (S52). When the test mode flag 73k is off (S52: Yes), the value of the sensor peak value memory 73c of the first peripheral sensor 20 to the third peripheral sensor 40 is weighted, and the result is stored in the velocity memory 73j (S53). ). That is, the velocity (impact strength) due to impact in the peripheral sensor impact processing is calculated by weighting the peak values of the first peripheral sensor 20 to the third peripheral sensor 40. Assuming that the values of the sensor peak value memory 73c of the first peripheral sensor 20 to the third peripheral sensor 40 are peak_s1, peak_s2, and peak_s3, respectively, velocity Vl is calculated by the weighting operation of the formula 3.

Here, gain_s1, gain_s2, and gain_s3 are gain constants, which are "0.2", "0.2", and "0.2", respectively. It should be noted that each gain constant is not necessarily limited to the above-mentioned value, and may be appropriately set according to the size and material of the striking surface, the detection sensitivity of the first peripheral sensor 20 to the third peripheral sensor 40, and the like. .. Further, gain_Mix_v is a value set by the user and is a value set by an input device (not shown) of the electronic drum 1. Note that gain_Mix_v is not limited to the same value as gain_Mix_v in Equation 1, and another value may be set.

After the processing of S53, "100" is stored in the striking position memory 73i (S54). The conditions for executing this S54 are that the peripheral sensor scan flag 73e is on (FIG. 8, S12: Yes), the central sensor 10 does not detect a hit (FIG. 8, S22: No), and the scan time. Is 2 ms or more (S50: Yes). That is, there is a case where the impact is detected by any one of the first peripheral sensor 20 to the third peripheral sensor 40, but the impact is not detected by the central sensor 10 within the scan time. In other words, it is a case where the striking surface of the electronic drum 1 is weakly striked in the peripheral portion of the striking surface. This is not only when the outer peripheral side of the first peripheral sensor 20 to the third peripheral sensor 40 is weakly struck, but also when the inner peripheral side of the first peripheral sensor 20 to the third peripheral sensor 40 is weakly struck, and the central sensor 10 is struck. The case where the blow is not detected is also included. When the inner peripheral side of the first peripheral sensor 20 to the third peripheral sensor 40 is weakly hit, the hitting position is accurately calculated from the time difference ΔT1 and ΔT2 of the hit peaks. On the other hand, when the outer peripheral side is weakly hit, as described above, the hitting position is not accurately calculated from the time difference ΔT1 and ΔT2 of the hitting peak, and the positions of the first peripheral sensor 20 to the third peripheral sensor 40 are the hitting positions. It is said that. Further, since the central sensor 10 does not detect the impact, the impact position cannot be calculated from the pitch ΔThw of the initial half wave of the central sensor 10. Therefore, in the present embodiment, for the sake of simplification of processing, a hit is detected by any of the first peripheral sensor 20 to the third peripheral sensor 40, but if the hit is not detected by the central sensor 10, the hit position is reached. Is set to "100", which is the same as the position of the first peripheral sensor 20 to the third peripheral sensor 40, and the striking position is used as an instruction to generate a musical tone.

After the processing of S54, a musical tone generation instruction corresponding to the value of the striking position memory 73i and the value of the velocity memory 73j is output to the sound source 76 (S55).

If no hit is detected by the central sensor 10 within the scan time by the peripheral sensor, such as a weak hit that cannot be detected by the central sensor 10 in the peripheral portion of the striking surface, the first peripheral sensor 20 to The weak hit is detected by the third peripheral sensor 40, and an instruction to generate a musical tone is given. That is, if the hit is not detected by the central sensor 10 within the scan time by the peripheral sensor after the hit of the first peripheral sensor 20 to the third peripheral sensor 40 is detected, the hit is not detected by the central sensor 10 without waiting. An instruction to generate a musical tone is given. Therefore, even in this case, the instruction to generate the musical tone is not delayed.

In the process of S52, when the test mode flag 73k is on (S52: No), the values of the sensor peak value memory 73c of the central sensor 10 and the first peripheral sensor 20 to the third peripheral sensor 40 are included in the MIDI SysEx message. Is output (S56). If the scan time is smaller than 2 ms in the process of S50, the process of S51 to S56 is skipped. Then, after the processing of S50, S55, and S56, the peripheral sensor impact processing is completed, and the process returns to the periodic processing of FIG.

From the above, when the striking position by the first peripheral sensor 20 to the third peripheral sensor 40 is 0 to 75, the striking is performed by the central portion of the striking surface of the electronic drum 1, and in the central sensor 10, the pitch ΔThw of the initial half wave. Since there is a possibility that the hitting position cannot be completely detected, the hitting position is calculated only by the hitting position by the first peripheral sensor 20 to the third peripheral sensor 40. That is, "0" is set in pre_gain_c (value of the central sensor striking position gain memory 73f) of the formula 2. When the striking position by the first peripheral sensor 20 to the third peripheral sensor 40 is between 75 and 100, the striking position is detected for both the central sensor 10 and the first peripheral sensor 20 to the third peripheral sensor 40. Therefore, the striking position is calculated by the weighting calculation of both. At this time, "0.5" is set in the pre_gain_c (value of the central sensor impact position gain memory 73f) of the mathematical formula 2. The value of pre_gain_c set in this case is not necessarily limited to "0.5", and may be appropriately set according to the size of the striking surface, the material, and the like.

When the striking position by the first peripheral sensor 20 to the third peripheral sensor 40 is 100 or more, that is, the outer periphery from the position of the first peripheral sensor 20 to the third peripheral sensor 40 (the position of "100" in FIG. 3). On the side. In the present embodiment, as shown in FIG. 5B, when the striking position by the first peripheral sensor 20 to the third peripheral sensor 40 is on the outer peripheral side of the first peripheral sensor 20 to the third peripheral sensor 40, the first peripheral sensor The position is "100", which is the same as the position of the 20th to 3rd peripheral sensors 40. On the other hand, since the striking position by the central sensor 10 is accurately acquired, the striking position is calculated by the weighting calculation of both.

Further, when the central sensor 10 detects a hit before the first peripheral sensor 20 to the third peripheral sensor 40, it is instructed to generate a musical tone after the scan time by the central sensor 10 for 2 ms. Even if the first peripheral sensor 20 to the third peripheral sensor 40 detect the impact before the central sensor 10, and then the central sensor 10 does not detect the impact, the musical sound is generated after the scan time by the peripheral sensor of 2 ms. You will be instructed. When the first peripheral sensor 20 to the third peripheral sensor 40 detect the impact before the central sensor 10, and then the central sensor 10 detects the impact, the scan time of up to 4 ms (scan time by the central sensor 10 + peripheral sensor). The generation of musical tones is not instructed until after the scan time). However, even in the prior art, it was instructed to generate a musical tone after a scan time of 2 ms after the central sensor 10 detected the impact. Also in the present embodiment, the point that the generation of the musical tone is instructed after the scan time by the central sensor 10 for 2 ms after the central sensor 10 detects the impact is the same as the conventional technique. The difference is that the first peripheral sensor 20 to the third peripheral sensor 40 detect the impact before the central sensor 10 detects the impact. Therefore, after the impact is detected by the central sensor 10 or the first peripheral sensor 20 to the third peripheral sensor 40, after the scan time by the central sensor 10 and / or the scan time by the peripheral sensor, that is, after a maximum of 4 ms, the impact position and velocity. Is calculated, so that the instruction to generate the musical tone is not delayed. Therefore, it is possible to play the electronic drum 1 with good response to a hit.

From the above, it is more accurate by changing the weighting of the impact by the central sensor 10, the first peripheral sensor 20 to the third peripheral sensor 40, which is used to calculate the impact position according to the detected impact position. The hitting position can be calculated.

As described above, the electronic drum 1 in the present embodiment has a central sensor 10 disposed in the center of the striking surface and first peripheral sensors 20 to third peripheral sensors 40 disposed in the peripheral portion of the striking surface. It is composed of and. Further, the first peripheral sensor 20 to the third peripheral sensor 40 are arranged at equal intervals on the circumference centered on the center sensor 10, and even if any position in the circumference is hit. Within the scan time by the central sensor 10 for 2 ms after the central sensor 10 detects the impact, the first peripheral sensor 20 to the third peripheral sensor 40 are all arranged at positions where the impact can be detected. Then, the velocity (strike strength) and the striking position are calculated according to the respective sensor output values detected by the striking of the electronic drum 1 against the striking surface, and based on the calculated velocity and the striking position, the velocity (strike strength) and the striking position are calculated. An instruction to generate a musical tone is given.

First, the velocity is calculated based on the peak of the impact detected by the central sensor 10 and the first peripheral sensor 20 to the third peripheral sensor 40. Specifically, when the central sensor 10 detects an impact before the first peripheral sensor 20 to the third peripheral sensor 40 due to the impact on the striking surface of the electronic drum 1, the central sensor 10 is detected from the impact detected by the central sensor 10. The scan time is timed according to the above, and after the end of the scan time, the velocity is calculated based on the peak of the impact detected by the central sensor 10 and the first peripheral sensor 20 to the third peripheral sensor 40.

In this way, since the velocity is calculated based on the impact peaks detected by the central sensor 10 and the first peripheral sensor 20 to the third peripheral sensor 40, the distribution of the impact sensitivity of the striking surface should be made substantially uniform. It is possible to eliminate the so-called hot spot where the striking sound becomes abnormally loud at the central portion of the striking surface where the central sensor 10 is located. Further, even if the time difference between the central sensor 10 and the first peripheral sensor 20 to the third peripheral sensor 40 for detecting the impact becomes large as a result of the large striking surface, the velocity is calculated from the first peripheral sensor 20 to. When the central sensor 10 detects an impact before the third peripheral sensor 40, it is performed after the scan time (that is, 2 ms) from the detection of the impact of the central sensor 10, so that the musical sound generation instruction is not delayed. ..

If no hit is detected by the central sensor 10 within the scan time by the peripheral sensor, such as a weak hit that cannot be detected by the central sensor 10 in the peripheral portion of the striking surface, the first peripheral sensor 20 to The weak hit is detected by the third peripheral sensor 40, and an instruction to generate a musical tone is given. That is, if the hit is not detected by the central sensor 10 within the scan time by the peripheral sensor after the hit of the first peripheral sensor 20 to the third peripheral sensor 40 is detected, the hit is not detected by the central sensor 10 without waiting. An instruction to generate a musical tone is given. Therefore, even in this case, the instruction to generate the musical tone is not delayed.

On the other hand, the striking position is calculated from the striking position by the central sensor 10 and the striking position by the first peripheral sensor 20 to the third peripheral sensor 40. Specifically, first, the striking position of the electronic drum 1 by the first peripheral sensor 20 to the third peripheral sensor 40 has a time difference ΔT1 for detecting the peak between the first peripheral sensor 20 and the second peripheral sensor 30, and the first. It is calculated by referring to the time difference ΔT2 for detecting the peak between the peripheral sensor 20 and the third peripheral sensor 40 in the peripheral sensor impact position table 72c. On the other hand, the striking position by the central sensor 10 is calculated by referring to the pitch ΔThw of the initial half wave of the striking detected by the central sensor 10 in the central sensor striking position table 72b. Then, the striking position is calculated by weighting the striking position by the first peripheral sensor 20 to the third peripheral sensor 40 and the striking position by the central sensor 10.

When any position in the circumference is hit, the first peripheral sensor 20 to the third peripheral sensor 40 have a second position within the scan time by the central sensor 10 of 2 ms after the central sensor 10 detects the hit. It is arranged at a position where a hit can be detected by all of the peripheral sensors 20 to the third peripheral sensor 40. Therefore, the impact detection by the first peripheral sensor 20 to the third peripheral sensor 40 is performed within the scan time by the central sensor 10, and the first peripheral sensor 20 to the third peripheral sensor 40 by the first peripheral sensor 20 to the third peripheral sensor 40. 3 It is possible to calculate the striking position in the circumference in which the peripheral sensor 40 is arranged. On the other hand, the striking position of the peripheral portion of the striking surface is calculated based on the pitch ΔThw of the initial half wave detected by the central sensor 10. Then, depending on the striking position indicated by the striking position calculated by the first peripheral sensor 20 to the third peripheral sensor 40, the striking position obtained from the first peripheral sensor 20 to the third peripheral sensor 40 and the striking position obtained from the central sensor 10 are obtained. The striking position is calculated by a weighting operation with the striking position. Since the striking position is calculated by this weighting calculation, it is possible to calculate the striking position more accurately.

Here, the first peripheral sensor 20 to the third peripheral sensor 40 have peaks due to the same impact within the scan time by the central sensor 10 of 2 ms after the central sensor 10 detects the impact when the impact surface is impacted. Is arranged at a position (position of "100" in FIG. 3) that can be detected by all of the first peripheral sensor 20 to the third peripheral sensor 40. Therefore, the detection by the first peripheral sensor 20 to the third peripheral sensor 40 is performed within the scan time by the central sensor 10, and the first peripheral sensor 20 to the third peripheral sensor 40 are arranged in the circumference. The striking position by the peripheral sensors 20 to the third peripheral sensor 40 can be calculated. On the other hand, the striking position by the central sensor 10 is calculated based on the pitch ΔThw of the initial half wave detected by the central sensor 10.

Here, the first peripheral sensor 20 to the third peripheral sensor 40 have a pitch ΔThw of the initial half wave within the scan time by the central sensor 10 after the central sensor 10 detects the impact when the striking surface is impacted. Is arranged at a position where it can be detected. Therefore, when a position outside the circumference is hit, the central sensor 10 can detect the pitch ΔThw of the initial half wave within the scan time by the central sensor 10, and based on this, the hit position by the central sensor 10 is calculated. To. Then, the striking position is calculated by weighting the striking position by the central sensor 10 and the striking position by the first peripheral sensor 20 to the third peripheral sensor 40. On the other hand, if the vicinity of the center of the striking surface of the electronic drum 1 is hit within the circumference, the pitch ΔThw of the initial half wave may not be completely detected by the central sensor 10. Therefore, when the striking position by the first peripheral sensor 20 to the third peripheral sensor 40 is near the center of the striking surface of the electronic drum 1 (that is, the position of "75" or less), the striking position after the scan time by the central sensor 10 In the calculation of, the striking position by the first peripheral sensor 20 to the third peripheral sensor 40 is defined as the striking position. Therefore, even when the pitch ΔThw of the initial half wave cannot be completely detected by the central sensor 10, the striking position can be calculated within the scan time by the central sensor 10.

In this way, the striking position in the circumference is around the peak time difference ΔT1 between the first peripheral sensor 20 and the second peripheral sensor 30 and the peak time difference ΔT2 between the first peripheral sensor 20 and the third peripheral sensor 40. The impact position outside the circumference is calculated by referring to the sensor impact position table 72c, and the initial half-wave pitch ΔThw detected by the central sensor 10 is calculated by referring to the central sensor impact position table 72b. The striking position inside and outside the circumference can be calculated based on the detection result of the striking within the scan time by the central sensor 10. Therefore, even when the striking surface is formed to be large, the striking position can be calculated quickly, so that the instruction to generate the musical tone is not delayed.

When only the central sensor 10 is used to detect the striking strength (velocity), a so-called hot spot appears near the center of the striking surface. In addition, if the area around the striking surface is struck weakly, the striking may not be detected. In order to alleviate this, in the present embodiment, the first peripheral sensor 20 to the third peripheral sensor 40 are added.

Further, when only the first peripheral sensor 20 to the third peripheral sensor 40 are used to detect the striking position, the striking position on the outer peripheral side of the first peripheral sensor 20 to the third peripheral sensor 40 cannot be detected. In order to solve this, when the first peripheral sensor 20 to the third peripheral sensor 40 are placed on the outermost circumference of the striking surface, it takes time for all the first peripheral sensors 20 to the third peripheral sensor 40 to detect the impact. In short, the instruction to generate a musical tone is delayed. If the peripheral sensor is placed on the inner peripheral side in order to reduce the delay, the striking position on the outer peripheral side cannot be detected from the first peripheral sensor 20 to the third peripheral sensor 40. Therefore, in the present embodiment, by using the central sensor 10 in addition to the first peripheral sensor 20 to the third peripheral sensor 40, the peripheral portion of the striking surface (that is, the first peripheral portion) is used while reducing the delay of the musical sound generation instruction. It is possible to detect the striking position of the sensors 20 to the outer peripheral side of the third peripheral sensor 40).

Although the present invention has been described above based on the embodiments, the present invention is not limited to the above-described embodiments, and it is easy that various improvements and changes can be made without departing from the spirit of the present invention. It can be inferred from.

In the above embodiment, the electronic drum 1 has been described as an example of the electronic percussion instrument. However, the present invention is not limited to this, and may be applied to the simulation of other percussion instruments such as bass drums, snares, toms, and cymbals.

In the above embodiment, the case where the cushion member 24 of the first peripheral sensor 20 to the third peripheral sensor 40 is formed of the same elastic material as the cushion member 14 of the central sensor 10 has been described. However, it is not always limited to this. For example, when the cushion member 24 is formed of an elastic material such as sponge, rubber, or a thermoplastic elastomer, it is preferable to use an elastic material having a hardness higher than that of the cushion member 14. As a result, when the central portion of the striking surface is hit, the time from the detection of the hit by the central sensor 10 to the detection by the first peripheral sensor 20 to the third peripheral sensor 40 can be shortened. The control delay time can be shortened.

In the above embodiment, the thickness of the cushion member 24 of the first peripheral sensor 20 to the third peripheral sensor 40 is made thinner than the thickness of the cushion member 14 of the central sensor 10 (the facing distance between the head sensor 23 and the striking surface is shortened). The case where the head sensor 23 of the first peripheral sensor 20 to the third peripheral sensor 40 shortens the time until the impact is detected has been described. However, it is not always limited to this. For example, the cushion member 14 and the cushion member 24 may be formed to have the same thickness (or the thickness of the cushion member 24 may be formed to be thicker than the thickness of the cushion member 14).

In this case, by increasing the hardness of the material of the cushion member 24 (the cushion member 24 is composed of a material that easily transmits the vibration of the impact), the head sensor 23 of the first peripheral sensor 20 to the third peripheral sensor 40 can be used. The time until the impact is detected can be shortened. That is, at least the first peripheral sensor 20 to the third peripheral sensor 40 may be configured so that the transmission time of the striking signal when striking the striking surface is shorter than that of the central sensor 10, and the means thereof is not limited. As a result, when the central portion of the striking surface is hit, the time from the detection of the hit by the central sensor 10 to the detection by the first peripheral sensor 20 to the third peripheral sensor 40 can be shortened. The control delay time can be shortened (the delay of the musical tone generation instruction can be shortened).

Further, when the hardness of the material of the cushion member 24 is higher than that of the cushion member 14, it is more preferable that the cushion member 14 and the cushion member 24 are made of an elastic material of the same material and only the hardness of the cushion member 24 is increased. .. As a result, even if there is a difference in hardness between the cushion member 14 and the cushion member 24 (compared to the case where there is a difference in both hardness and material), the central sensor 10 and the first peripheral sensors 20 to the third periphery The characteristics (waveform, level, reaction time, etc.) of the impact output of the sensor 40 can be easily matched.

In the above embodiment, the central sensor 10 and the first peripheral sensor 20 to the third peripheral sensor 40 are composed of piezoelectric elements. However, the present invention is not limited to this, and any sensor such as an acceleration sensor or a pressure sensor that can detect the impact of the striking surface can be applied to the central sensor 10 and the first peripheral sensor 20 to the third peripheral sensor 40.

In the above embodiment, the case where the striking surface (membrane member 3a) is formed in a disk shape has been described. However, the striking surface is not necessarily limited to this, and the striking surface may be formed in a rectangular shape, a polygonal shape, or a shape in which a curved line and a straight line are combined. That is, regardless of the shape of the striking surface, as in the present embodiment, one central sensor 10 and the central sensor 10 are arranged at equal intervals along the circumference centered on the circle. At least three first peripheral sensors 20 to third peripheral sensors 40 to be provided may be arranged in a region formed as a striking surface.

That is, thereby, from the time difference of the peaks detected by the first peripheral sensor 20 to the third peripheral sensor 40, the striking position in the circumference in which the first peripheral sensor 20 to the third peripheral sensor 40 is arranged is detected. can. Further, the striking position outside the circumference in which the first peripheral sensor 20 to the third peripheral sensor 40 are arranged can be detected by the detection waveform of the striking signal by one central sensor. Therefore, even when the striking surface is formed in a rectangular shape, a polygonal shape, or a shape obtained by combining curves and straight lines, the striking position from the center of the striking surface is determined by the central sensor 10 and the first peripheral sensors 20 to 1. 3 It can be appropriately detected by the peripheral sensor 40.

In this case, the central sensor 10 may be arranged at a position off the center, and at least the first peripheral sensor 20 to the third peripheral sensor 40 may be arranged at equal intervals on the circumference centered on the central sensor 10. It may be configured to be arranged in. As a result, the calculation of the striking position can be appropriately performed based on the detection results of the central sensor 10 and the first peripheral sensor 20 to the third peripheral sensor 40.

In the above embodiment, the first peripheral sensor 20 to the third peripheral sensor 40 are arranged at equal intervals along the circumference centered on the central sensor 10. However, the present invention is not limited to this, and the first peripheral sensor 20 to the third peripheral sensor 40 are not on the circumference centered on the central sensor 10, but have a polygonal shape or an elliptical shape surrounding the central sensor 10. It may be arranged on a line or may be arranged at irregular intervals. In this case, the peripheral sensor striking position table 72c corresponding to such an arrangement may be created by actual measurement or the like to calculate the striking position. Further, each gain constant in Equation 1 may be appropriately set by actual measurement or the like, and the velocity may be calculated.

In the above embodiment, one central sensor 10 is arranged in the center of the striking surface. However, the present invention is not limited to this, and a configuration in which two or more central sensors 10 are arranged may be used. In that case, instead of the impact detection result by one central sensor 10 in the above embodiment, the average value or the like of the impact detection results by the plurality of central sensors 10 may be used for calculating the velocity and the impact position.

In the above embodiment, the three peripheral sensors 20 to the third peripheral sensor 40 are arranged at equal intervals on the circumference centered on the central sensor 10. However, the present invention is not limited to this, and three or more peripheral sensors may be arranged. In this case, the peripheral sensors are arranged at equal intervals on the circumference centered on the center sensor 10, and the peak time difference of the impact in each peripheral sensor is set by the peripheral sensor impact position table 72c with the peripheral sensor as the base point. When a hit is detected, the hit position may be acquired by referring to the peak time difference of the hit in each peripheral sensor in the peripheral sensor hit position table 72c.

Further, two peripheral sensors may be arranged. Even in this case, the striking position in the linear direction connecting the two peripheral sensors can be detected. The striking position can be calculated by a weighting operation between the striking position obtained from the two peripheral sensors and the striking position obtained from the pitch ΔThw of the initial half wave of the central sensor 10. However, it is not possible to detect the striking position in the direction intersecting the straight line connecting the two peripheral sensors.

Further, one peripheral sensor may be arranged. In this case, the peripheral sensor is one circular ring sensor centered on the central sensor 10 (the sensor itself has a ring shape, or one sensor detects vibration of a ring-shaped member in contact with the head. Sensor). The velocity in this case is calculated by a weighting operation between the peak value of the impact detected by the central sensor 10 and the peak value of the impact detected by the ring sensor. Then, as for the striking position, first, the striking position (hereinafter referred to as “the striking position due to the time difference”) is calculated by the time difference between the striking peak detected by the ring sensor and the striking peak detected by the central sensor 10. This makes it possible to calculate the striking position within the circumference in which the ring sensor is arranged.

When the striking position due to this time difference is a position where the pitch ΔThw of the initial half wave of the central sensor 10 can be completely detected within the scan time by the central sensor 10 (for example, the outer peripheral side from the position “75” in FIG. 3). Is calculated by weighting the striking position due to the time difference and the striking position calculated by the pitch ΔThw of the initial half wave of the central sensor 10. On the other hand, when the result of the striking position due to the time difference is a position where the pitch ΔThw of the initial half wave of the central sensor 10 cannot be completely detected within the scan time by the central sensor 10, the striking position due to the time difference is set as the striking position.

In this way, the striking position in the circumference where the ring sensor is arranged is calculated from the time difference between the striking peak detected by the ring sensor and the striking peak detected by the central sensor 10, and is outside the circumference. By calculating the striking position based on the pitch ΔThw of the initial half wave of the central sensor 10, the striking position inside and outside the circumference can be calculated based on the detection result of the striking within the scan time by the central sensor 10. Therefore, even when the striking surface is formed to be large, the striking position can be calculated quickly, so that the instruction to generate the musical tone is not delayed.

Further, when the striking position due to the time difference is the position of the ring sensor, it cannot be determined whether the position of the ring sensor is striked or the outer peripheral side of the ring sensor is striked. In this case, the striking position calculated by the pitch ΔThw of the initial half wave of the central sensor 10 may be used as the striking position.

The striking position due to the time difference was calculated from the time difference between the striking peak detected by the ring sensor and the striking peak detected by the central sensor 10. The striking position may be calculated based on the difference or ratio with the peak value of striking. Further, the striking position may be calculated by the detection time difference (that is, the difference in the signal arrival time) between the ring sensor and the central sensor 10 for falling (or rising).

The striking position by the central sensor 10 is calculated by the pitch ΔThw of the initial half wave, but the striking position may be calculated based on the peak position of the initial half wave or the area of the initial half wave detected by the central sensor 10. ..

From the above, the impact position obtained from a plurality of sensors (difference or ratio of impact detection time or impact intensity) among the central sensor 10 and at least one peripheral sensor, and the initial half wave of the central sensor 10 were obtained. The striking position can be calculated by a weighting operation with the striking position.

In the above embodiment, the time measured by the central sensor 10 and the scan time by the peripheral sensors are both set to 2 ms. However, the time is not necessarily limited to this, and the time counting time may be 2 ms or more or 2 ms or less depending on the size of the striking surface and the material of the striking surface. Further, the time counting time of the scan time by the central sensor 10 and the scan time by the peripheral sensors may be different. For example, since the peak appearance of the central sensor 10 is slower than that of the first peripheral sensor 20 to the third peripheral sensor 40, the scan time is lengthened, and the peak appearance of the first peripheral sensor 20 to the third peripheral sensor 40 is early. It may be configured to shorten the scan time.

In the above embodiment, when a hit by the central sensor 10 is detected during the scan time by the peripheral sensor, the scan time by the peripheral sensor is stopped and the scan time by the central sensor 10 is started. However, the present invention is not limited to this, and even if a hit by the central sensor 10 is detected during the scan time by the peripheral sensor, the scan time by the central sensor 10 is not performed, and after the scan time by the peripheral sensor, by then. The velocity and the striking position may be calculated from the obtained sensor value ring buffer 73b value and the sensor peak value memory 73c value, and a musical tone generation instruction may be given. In this case, the velocity may be the value of the sensor peak value memory 73c of the central sensor 10 obtained within the scan time by the peripheral sensor as the peak value of the central sensor 10.

Further, regarding the striking position, the fact that any one of the first peripheral sensor 20 to the third peripheral sensor 40 detects the striking first means that the first peripheral sensor 20 to the third peripheral sensor 40 has a higher impact position than the central sensor 10. Since it is considered that a close position was hit, a predetermined position from the intermediate position (position of "50") between the central sensor 10 and the first peripheral sensor 20 to the third peripheral sensor 40 to the outermost circumference (position of "127"). (For example, the position of "100") may be set as the striking position. Alternatively, the difference in time from the start time of the initial half wave of the central sensor 10 obtained within the scan time by the peripheral sensor to the end of the scan time by the peripheral sensor is defined as the pitch ΔThw of the initial half wave of the central sensor 10 and is set to Equation 2. The pre_gain_c (that is, the value of the central sensor striking position gain memory 73f) may be set to a larger value (for example, 0.6) than usual, and the striking position may be calculated by the weighting calculation of Equation 2. As a result, since it is not necessary to wait for the scan time by the central sensor 10, the delay of the musical tone generation instruction is further reduced, and the responsiveness to the hit is improved.

In the above embodiment, when a hit by the central sensor 10 is detected during the scan time by the peripheral sensor, the scan time by the peripheral sensor is stopped and the scan time by the central sensor 10 is started. However, the present invention is not limited to this, and if a hit by the central sensor 10 is detected during the scan time by the peripheral sensor, the scan time by the peripheral sensor is stopped and "scan time by the central sensor 10 + peripheral sensor". May be started, and may be configured to be distinguished from the “scan time by the central sensor 10”. In this case, the delay of the musical tone generation instruction can be reduced by appropriately adjusting the scan time time by the central sensor 10 + peripheral sensor to be shorter than 2 ms.

In the above embodiment, when the striking position calculated by the first peripheral sensor 20 to the third peripheral sensor 40 is "75" or more, the striking position by the central sensor 10 and the first peripheral sensor 20 to the third peripheral sensor 40 The striking position was calculated by the weighting calculation with the striking position by, and when it was smaller than "75", the striking position was calculated only by the striking position calculated by the first peripheral sensor 20 to the third peripheral sensor 40. However, the present invention is not limited to this, and only the striking position calculated by the first peripheral sensor 20 to the third peripheral sensor 40 is used to determine the striking position and the striking surface area calculated by the central sensor 10. The configuration may be such that only the position is adjacent to the area of the striking surface for which the striking position is calculated.

In the above embodiment, the threshold value of whether or not to calculate the striking position only at the striking position detected by the first peripheral sensor 20 to the third peripheral sensor 40 is set to the position of “75”. However, the boundary value is not necessarily limited to this, and the boundary value is set to "75" or less according to the impact detection characteristics of the central sensor 10 and the first peripheral sensor 20 to the third peripheral sensor 40, such as the size and material of the striking surface. It may be a value of "75" or a value of "75" or more.

In the above embodiment, the striking position is acquired by referring to the central sensor impact position table 72b with the pitch ΔThw of the initial half wave of the voltage waveform due to the impact of the central sensor 10. However, the present invention is not limited to this, and the striking position may be acquired from the pitch ΔThw of the initial half wave by calculation. In that case, since the central sensor impact position table 72b can be omitted, the size of the ROM 72 can be reduced.

In the above embodiment, the striking position by the central sensor 10 is calculated by referring to the pitch ΔThw of the initial half wave detected by the central sensor 10 with the central sensor striking position table 72b. However, the present invention is not limited to this, and the striking position may be calculated based on the peak position of the initial half wave detected by the central sensor 10, the area of the initial half wave, and the like.

In the above embodiment, the impact position is acquired by referring to the peripheral sensor impact position table 72c by the time difference ΔT1 and ΔT2 of the impact peak between the first peripheral sensor 20, the second peripheral sensor 30, and the third peripheral sensor 40. I decided to do it. However, the present invention is not limited to this, and the impact position may be acquired by calculation from the time difference ΔT1 and ΔT2 of the impact peaks. In that case, the size of the ROM 72 can be reduced because the peripheral sensor impact position table 72c can be omitted.

In the above embodiment, the striking positions of the first peripheral sensor 20 to the third peripheral sensor 40 are the time difference ΔT1 of 30 peaks between the first peripheral sensor 20 and the second peripheral sensor, and the first peripheral sensor 20 and the third peripheral. The peak time difference ΔT2 from the sensor 40 was calculated by referring to the peripheral sensor impact position table 72c. However, the present invention is not limited to this, and the striking position may be calculated based on the difference in peak values between the first peripheral sensor 20 and the third peripheral sensor 40 and the ratio of peak values.

In the above embodiment, the peak time difference between the first peripheral sensor 20 and the second peripheral sensor 30 is ΔT1, and the peak time difference between the first peripheral sensor 20 and the third peripheral sensor 40 is ΔT2. However, the present invention is not limited to this, and the difference in detection time (that is, the difference in signal arrival time) between the first peripheral sensor 20 and the second peripheral sensor 30 for falling (or rising) is set to ΔT1 and the first peripheral sensor 20. The difference in detection time between the sensor 40 and the third peripheral sensor 40 is set to ΔT2, and the ΔT1 and ΔT2 are used from the peripheral sensor impact position table 72c to the first peripheral sensor 20 to the third peripheral sensor 40. The striking position may be calculated.

In the above embodiment, the striking position is acquired by the difference in the detection time of the striking between the first peripheral sensor 20 and the third peripheral sensor 40. However, the present invention is not limited to this, and the impact position may be acquired by the difference in impact detection time between the first peripheral sensor 20 to the third peripheral sensor 40 and the central sensor 10. In that case, the striking position corresponding to the peak time difference between the central sensor 10 and the first peripheral sensor 20 to the third peripheral sensor 40 may be added to the peripheral sensor striking position table 72c.

1 Electronic drum (electronic percussion instrument)
3a Membrane member (strike surface)
7 Control device 10 Central sensor (part of impact sensor)
20 First peripheral sensor (part of peripheral sensor, part of impact sensor)
30 Second peripheral sensor (part of peripheral sensor, part of impact sensor)
40 Third peripheral sensor (part of peripheral sensor, part of impact sensor)
72c Peripheral sensor hitting position table (hit position table)
S34 1st position calculation means S36 2nd position calculation means S40 3rd position calculation means S41, S55 Pronunciation instruction means

Claims (5)

In an electronic percussion instrument equipped with a striking surface and a striking sensor that detects a striking surface.
The striking sensor is configured to include a central sensor disposed at the center of the striking surface and one or more peripheral sensors when the striking surface is viewed in a plane.
First position calculation means for calculating the impact position from the central sensor based on the initial half wave when the initial half wave of the impact waveform is detected within a predetermined time after the central sensor detects the impact. When,
A second position calculating means for calculating the impact position based on the difference in impact detection of the central sensor or a plurality of sensors in the peripheral sensor, including at least one peripheral sensor.
It is provided with a pronunciation indicating means for instructing the pronunciation of the striking sound based on the striking position calculated by the first and second position calculating means.
When the striking surface is hit, the peripheral sensor is within a region where the peripheral sensor can detect the hit within a predetermined time after the central sensor detects the hit, and the central sensor is the center sensor. An electronic percussion instrument, characterized in that the central sensor is arranged in a region where the initial half wave of the striking waveform can be detected within a predetermined time after detecting the striking. At least three peripheral sensors are arranged at equal intervals on the circumference centered on the central sensor, and any position in the circumference formed by the three peripheral sensors is hit. Even in this case, the central sensor detects the impact within the region where the peripheral sensor can detect the impact within a predetermined time after the central sensor detects the impact, and when the striking surface is impacted. The central sensor is arranged in a region where the initial half wave of the impact waveform can be detected within a predetermined time.
Claim 1 is characterized in that the second position calculating means calculates a striking position in the circumference in which each peripheral sensor is arranged based on a difference in impact detection of each peripheral sensor. Described electronic percussion instrument. A hit position table is provided in which the difference in hit detection of each peripheral sensor is used as a variable and the hit position corresponding to the variable is stored.
The electronic percussion instrument according to claim 2, wherein the second position calculating means calculates a hitting position based on the hitting position table. The peripheral sensor is composed of a ring sensor formed in a circular shape with the central sensor as the center of the circle, and the center of the peripheral sensor is hit at any position in the circumference formed by the ring sensor. Within a predetermined time after the sensor detects a hit, and within a predetermined time after the central sensor detects the hit when the hit surface is hit. The central sensor is arranged in a region where the initial half wave of the impact waveform can be detected.
The second position calculating means is characterized in that it calculates the striking position in the circumference in which the ring sensor is arranged based on the difference in impact detection between the central sensor and the ring sensor. The electronic percussion instrument according to claim 1. A third position calculating means for calculating the hitting position by performing a weighting operation on each of the hitting position calculated by the first position calculating means and the hitting position calculated by the second position calculating means is provided.
The electronic percussion instrument according to any one of claims 1 to 4, wherein the sounding instruction means instructs the sound of a striking sound based on the striking position calculated by the third position calculating means.

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