JP2915435B2 - Information processing apparatus and information processing method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an ultrasonic distance measuring apparatus, or an information processing apparatus in general, and various information processing apparatuses incorporating a distance measuring technique using the propagation of ultrasonic waves. It is about.

[Related Art] An ultrasonic coordinate input device is one of devices devised as an application device for ultrasonic distance measurement. Hereinafter, the present invention will be described using this apparatus as an example.

FIG. 8 is a schematic view of a generally devised ultrasonic coordinate input device. Reference numeral 1 denotes a coordinate pointing device (hereinafter referred to as a pen), which has a piezoelectric element incorporated therein and is an oscillator that emits a desired ultrasonic signal from its tip. 2a to 2c are senses, which are receivers that receive an ultrasonic signal emitted from a pen via a propagator. Reference numeral 3 denotes a propagation body, which is a propagation medium of ultrasonic waves, and is made of glass, an aluminum plate, or the like. Reference numeral 4 denotes a vibration isolator, which is set for the purpose of preventing reflected waves other than the waves from the pen 1 from entering the sensors 2a to 2c. In the ultrasonic coordinate input device having the above-described configuration, the coordinates of the designated point are calculated from the distances between the two or more sensors and the designated point.

Various methods for calculating the distance between the sensor and the designated point have been devised, but basically, the distance is calculated based on the arrival time of the ultrasonic signal emitted from the pen to the sensor. When using transverse ultrasonic waves having different group velocities and phase velocities, the envelope of the received waveform is used to determine the group arrival time and rough distance measurement is performed. Phase arrival time by detecting the phase of
It has finer precision.

Next, a procedure for calculating the distance r between the pen and the sensor from two pieces of time information of the group arrival time and the phase arrival time will be described.
First, when a voltage as shown in FIG. 9 is applied to the piezoelectric element in the pen, the received signal of the sensor becomes as shown in FIG. On the other hand, when the peak position is detected as the group arrival position _tg, as shown in FIG. 11, the circuit of the first-stage amplifier 5, the full-wave rectifier 6, the low-pass filter 7, and the differentiating circuit 8 is applied to the sensor output signal. After that, the zero crossing of the differential signal is detected by the comparator 9 and the time is taken as the group arrival time.
Recognized as t _g .

Thus, if the group velocity and upsilon _g, but can be r calculated by r = υ _g · t _g, because due to the method of detecting the time based on the envelope of the signal output size and the filter characteristics Inevitably, some fluctuation Δ
t occurs. Generally, detecting a specific phase zero crossing point and determining the time can obtain a value with less fluctuation.

Therefore, since when defining the detection point as that phase zero cross just after the group arrival time t _g determined, the phases of the group with upsilon _g ≠ upsilon distance for is a _p r deviates, the a phase arrival time t _p Stepwise ones as shown in Fig. 12 are observed. This stage indicates the movement of the phase detection point, and the joint between the stages is a parallel movement of the signal period T. If υ _g and υ _p are equal and a constant phase detection point can always be observed, such a step cannot be performed and a phase arrival time t _p as shown by a straight line a is obtained.

Accordance connexion, may be converted to a phase arrival time t _p given to stepped to the original straight line a.

That is, t _pa ≒ (υ _g / υ _p ) t _g −t _of (t _of : offset value). However, since the group arrival time t _g has a large fluctuation, t _pi = nT ≒ (υ _g / υ _g Using the property _of t _g −t _of −t _p (n is an integer), t _pa = t _p + T × Int (t _pi /T+0.5)=t _p + T × Int [｛(υ _g / υ _p ) t _g −t _of −t _p ｝ /T+0.5], and t _pa is obtained. Finally, r is calculated by the following equation.

_{r = υ p · t pa -r} of (r of: offset _{value) = At p + B × Int} {Ct g + Dt p + E + 0.5} + F A: υ p B: υ p · T = λ C: (υ g _{/ υ p) / T = f} (υ s / υ p) D: -1 / T = -f E: -t of / TF: -r of [ problems invention is trying to solve] However, as described above In order to calculate the distance r between the pen and the sensor with high accuracy,
D, E, F) is a major premise. However,
Due to the nature of the method of utilizing the propagation of ultrasonic waves, such calculation constants are inevitably subject to subtle variations due to various physical constants of individual products, adjustment conditions, and the like. It is practically difficult to mass-produce products with coordinate accuracy.

The present invention eliminates the above-mentioned drawbacks of the related art, and makes it possible to determine the distance between the designated point and the sensor based on the arrival time of the ultrasonic wave, regardless of the subtle variations due to various physical constants and adjustment conditions of each device. An information processing apparatus and an information processing method for accurately calculating the information are provided.

[Means to be Solved by the Invention] In order to solve this problem, an information processing apparatus of the present invention is an information processing apparatus that calculates a distance between a designated point and a sensor based on an arrival time of an ultrasonic wave, Judgment means for judging the calibration mode, and calculation means for calculating a calibration parameter from arrival times of ultrasonic waves at a plurality of arbitrarily inputted continuous points when the judgment mode judges that the mode is the calibration mode. And updating means for updating a calibration parameter stored in advance to obtain the distance between the designated point and the sensor to the calibration parameter calculated by the calculating means.

Here, the calculating means, by substituting the group arrival time t _g and the phase arrival time t _p at a predetermined position on a predetermined arithmetic expression, the calculation parameters used to calculate the distance between the oscillation source and the sensor The group velocity υ _g , the phase velocity υ _p , and the frequency f are obtained. In addition, the calculating means performs a predetermined statistical calculation based on the group arrival time t _g and the phase arrival time t _p observed at arbitrary continuous positions, and calculates the group velocity { _g , phase velocity} of the calculation parameter.
_{Find p} and frequency f. Further, the calculating means calculates the group arrival time t _g and the phase arrival time t _p at a predetermined appropriate position.
Into a predetermined equation to calculate the phase velocity 計算
_p arrival, group arrival time obtained at arbitrary continuous plural positions
Request group velocity upsilon _g of calculated pursuant parameter to a predetermined statistical computation by t _g and the phase arrival time t _p.

An information processing apparatus according to the present invention is an information processing apparatus that calculates a distance between an indicated point and a sensor based on an arrival time of an ultrasonic wave, wherein a determination unit that determines a calibration mode, and the calibration mode is determined by the determination unit. When it is determined that the sensor position is determined, the sensor mounting position is calculated using a calculation parameter set from the arrival time of the ultrasonic wave at a predetermined appropriate position, and the deviation amount from the normal position is calculated. It is characterized by comprising calculating means, and updating means for updating the position correction amount of the sensor stored in advance for obtaining the distance between the designated point and the sensor to the displacement amount calculated by the calculating means.

Here, the calculating means, group velocity upsilon _g of the initially set calculation parameters based on the group arrival time t _g and the phase arrival time t _p at an appropriate position predetermined phase velocity upsilon _p, the frequency f
Is used to calculate the sensor mounting position, and the amount of deviation from the normal position is calculated.

Also, the information processing method of the present invention is an information processing method in an information processing apparatus that calculates a distance between an indicated point and a sensor based on an arrival time of an ultrasonic wave, and has a calibration mode. Calculate the calibration parameters from the arrival times of the ultrasonic waves at a plurality of points that are arbitrarily input, and calculate the calibration parameters stored in advance to determine the distance between the designated point and the sensor. It is characterized by updating to calibration parameters.

Here, in the calculating step, by substituting the group arrival time t _g and the phase arrival time t _p at a predetermined position on a predetermined arithmetic expression, the calculation parameters used to calculate the distance between the oscillation source and the sensor The group velocity υ _g , the phase velocity υ _p , and the frequency f are obtained. Further, in the calculation step, Yotsute a predetermined statistical computation by the group arrival time observed by any continuous multiple positions t _g and the phase arrival time t _p, the group velocity upsilon _g of calculation parameters, phase velocity upsilon _p , Frequency f. Further, in the calculating step calculates the phase velocity upsilon _p calculation by substituting the group arrival time t _g and the phase arrival time t _p of a suitable predetermined positions on a predetermined arithmetic expression parameter, any continuous Request group velocity upsilon _g of calculated pursuant parameter to a predetermined statistical computation by the time the group reached obtained at a plurality of positions t _g and the phase arrival time t _p.

Also, the information processing method of the present invention is an information processing method in an information processing apparatus that calculates a distance between an indicated point and a sensor based on an arrival time of an ultrasonic wave, and has a calibration mode. Calculate the mounting position of the sensor using the calculation parameters set from the arrival time of the ultrasonic wave at a predetermined appropriate position, calculate the amount of deviation from the normal position, between the designated point and the sensor It is characterized in that the position correction amount of the sensor stored in advance for obtaining the distance is updated to the calculated shift amount.

Here, in the calculating step, the group velocity upsilon _g of the initially set calculation parameters based on the group arrival time t _g and the phase arrival time t _p at an appropriate position predetermined phase velocity upsilon _p, the frequency f Is used to calculate the sensor mounting position, and the amount of deviation from the normal position is calculated.

[Operation] In such a configuration, the group arrival time observed at a predetermined appropriate position or any continuous plural positions.
Based on t _g and phase arrival time t _p , calculation parameters are newly set so that calibration can be performed, and optimum calculation parameters can be individually set and calibrated for each device. Further, it is possible to compensate for the secular change of the mounting position of the sensor.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

<First Embodiment> FIG. 1 is a diagram showing a configuration example of a calibration instruction point and an ultrasonic coordinate input device according to a first embodiment of the present invention.
In the figure, reference numeral 1 denotes a vibration pen, 2 denotes a sensor, 3 denotes a vibration plate, and 4 denotes an anti-vibration material. The vibration pen is controlled by a pen control unit 10, and a sensor control unit 20 includes each of the components shown in FIG. A circuit may be included. 100 is a CPU for arithmetic control, 101 is a ROM for storing a control program, and 102 is a RAM for auxiliary storage, which stores, for example, constants A, B, C, D, and E in this example. An output unit 103 outputs the input coordinates to a display screen or the like.

Pen and the sensor distance r as described above is obtained by _{r = A t p + B Int} {C t g + D t p + E + 0.5} + F, to integer within the second term of the equation {} term As long as the physical constant does not fluctuate such that the integer value shifts due to the conversion into an integer, the integer value n at a predetermined point should not fluctuate. Thus, for example, P
If (t _g , t _p ) at the three points 2,2, P3, P4 is known, the known n ^p2 , n
^p3, to n ^p4 than ^{_{C t g p2 + D t p}} p2 + E = n p2 C t g p3 + D t p p3 + E = n p3 C t g p4 + D t p p4 + E = n p4, C, D, and E It is possible to ask.

Similarly, regarding r, the known n ^p2 , n ^p3 , n ^p4 , r ^p2 , r
^p3, r ^p4 respect than _{^{A t p p2 + B n p2}} + F = r p2 A t p p3 + B n p3 + F = r p3 A t p p4 + B n p4 + F = r p4, A, B, be determined F It becomes possible.

It should be noted that, in carrying out the present embodiment, it is needless to say that each calibration instruction point and r, n correspond exactly. Therefore, the location of the calibration instruction point is
It is necessary to set a location which is shifted from the vicinity of a step in among the relationship between the phase arrival time t _p versus r as shown in FIG.
Incidentally, the step of phase arrival time t _p is approximately Occurs every time.

_{Examples, λ = 3mm, ν g =} 2350m / s, if υ _{p =} 1350m / s, it means that the step of phase arrival time t _p occurs about every 7 mm, a point to remove the vicinity well Set.

The flow of the system for realizing the above operation is shown in the flowchart of FIG. First, the system is put into the calibration mode by some switch operation. Then step
Three points are input in S1, calculation parameters are calculated in steps S2 and S3, and constants are switched in step S4. In addition,
The switching of the constants may be performed by means of rewriting on the RAM to be backed up, or by switching the setting of a dip switch which can be read by the microcomputer by some means.

Second Embodiment Next, a second embodiment of the present invention will be described.

A, B, and F are those that give absolute accuracy if the Int function gives a correct value in the r calculation formula. By the way, A, B, and F are parameters related to the phase velocity 及 び_p and the frequency f,
These are determined from the relationship between r and the phase arrival time t _p, but in general when obtaining the phase arrival time t _p the phase zero-cross detection, in relation r and a phase arrival time t _p, as shown in FIG. 3 each The linearity is good for each step, and the respective slopes そ れ ぞ れ_p are almost the same. In addition, T (= 1 / f) indicated by a break at each step is substantially uniform throughout. Therefore, even if these A, B, and F are determined by the method described in the first embodiment, a value close to the true value is obtained, and there is no practical problem.

However, C, D, and E in the Int function are parameters related to the group velocity υ _p . Generally, the relationship between r and the group arrival time t _g is observed as shown in FIG. It is very dangerous to determine C, D, and E by taking several points as in the example. That is, as shown in FIG.
When the relationship of the pair group arrival time t _g is obtained, which corresponds to be determined upsilon _p than two points as in FIG example is quite meaningless. Therefore, in general, to determine C, D, and E,
It is necessary to perform some statistical processing in addition to the above method.

Therefore, the following means is taken in this embodiment.
First, an arbitrary curve as shown in FIG. 4 is drawn at an appropriate speed at an arbitrary position on the propagator using an input pen, and (t _g , t _p )
Is input continuously. Then, as shown in FIG. 5, (t _g ,
t _p ) vs. r. In contrast, decide appropriately the initial value n of the integer value at the start point A (e.g. 0), then if the pen has occurred stepped phase arrival time t _p in a direction away from the sensor +1, in approaching direction -1 To associate an integer value n for each step. As a result, a data group as shown in FIG. 6 is created. Group arrival time independent variables it based on t _g, the phase arrival time t _p, the dependent variable was _{n n = C t g + D} t p + E '(E' = | E | -Int {| E | +0.5｝ −n _int ) Multiple regression is performed by the relational expression, and the optimal constants C, D, and E are statistically determined.

<Third Embodiment> As a reverse application example of the above-described embodiment, detection of a shift amount of a sensor position can be mentioned. Said first, second embodiment, and calculated back (t _g, t _p) to a constant when the distance calculated on the basis υ _g, υ _p, f when instructed appropriate position, R
The calibration was performed by means of an AM backup or a depth switch. However, υ _g , υ _p ,
f greatly depends on the variation of the thickness of the propagation body and the influence of the frequency characteristics of the ultrasonic transmission pen, and once it is set for each individual product, it is considered to be stable thereafter. It is the sensor position that is likely to change.
This is especially true in locations where the product itself is not in a static, stable environment and can be impacted frequently. Therefore, the sensor position is calculated backward using υ _g , υ _p , f which is initially set based on (t _g , t _p ) when the appropriate position is indicated,
By using a method of feeding back the result to a distance calculation formula, it is possible to correct the displacement of the sensor position.

Hereinafter, description will be made with reference to FIG. First, when the operation mode of the system is set to the calibration mode by some switch operation, the process proceeds from step S75 to step S76. Here, points P ₁ and P ₂ on the absolute coordinate x axis are pointed. Between P ₁ and the sensor S ₂ at that time, the distance between P ₂ and the sensor S _2, advance initially set upsilon _g, using upsilon _p, f, taken at step S77 (t _g
^p1, t _p ^p1), and calculates the ^{_{(t g p2, t p p2}} ) calculated in step S78 on the basis of, x component of the absolute coordinate of the sensor S ₂ based on the results. Similarly, point P ₆ and P ₇ on the absolute coordinate y axis, and based on (t _g ^P6 , t _p ^P6 ) and (t _g ^P7 , t _p ^P7 ) at that time,
Calculating the y component of the absolute coordinate of the sensor S _2. In this way, the absolute coordinates of all the sensors are obtained, the deviation from the original position is read, and the result is fed back to the coordinate calculation formula in the normal operation mode in step S79.

In the normal mode, the distance between the pen and the sensor is calculated in step S72, the designated coordinate is calculated in step S73, and then the correction is performed in step S74 based on the sensor shift correction amount set in step S79.

[Effects of the Invention] According to the present invention, the distance between the designated point and the sensor can be accurately calculated based on the arrival time of the ultrasonic wave, regardless of subtle variations due to various physical constants and adjustment conditions of each device. And an information processing method thereof.

That is, predetermined appropriate position or any successive plurality of positions in the observed group arrival time t _g, based on the phase arrival time t _p, the system configuration can be calibrated by setting the constant coefficient newly By taking, the optimal calculation constant can be set and calibrated individually for each product,
Variations in the physical constants of the components that make up the product, variations in the degree of mounting, and changes in the optimal calculation constants due to aging, etc., are easily absorbed not only at the time of factory shipment but also by servicemen and users calibrating in the market. And practical application of ultrasonic distance measurement application products that ensure stable accuracy.

[Brief description of the drawings]

FIG. 1 is a diagram showing the configuration of an instruction point for calibration and an ultrasonic coordinate input device in this embodiment. FIG. 2 is a flowchart showing a processing procedure in the first embodiment. FIG. 3 is a distance r and a group arrival time. t _g, shows a relationship between the phase arrival time t _p, Fig. 4 shows a calibration input example of the second embodiment, Figure 5 is a data number and the group arrival time in the second embodiment
t _g, diagram illustrating an example of the relationship between the phase arrival time t _p, Fig. 6 is a diagram showing the calibration data group in the second embodiment, Figure 7 is flow chart showing a processing procedure in the third embodiment, eighth FIG. 9 is a schematic diagram of a coordinate input device, FIG. 9 is a diagram showing a driving voltage of the pointing pen, FIG. 10 is a diagram showing a sensor output waveform, FIG. 11 is a diagram showing a configuration example of a signal processing circuit, FIG. The figure illustrates the distance calculation. In the figure, 1 ... coordinate indicating tool, 2,2a ~ 2c ... sensor, 3 ...
Propagator, 4… Vibration isolator, 5… First-stage amplifier, 6… Full-wave rectifier, 7… Low-pass filter, 8… Differentiation circuit, 9
...... Comparator, 10 ... Pen control unit, 20 ... Sensor control unit, 100 ... CPU, 101 ... ROM, 102 ... RAM, 103 ...
Output unit.

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields investigated (Int.Cl. ⁶ , DB name) G01S 5/22 G01B 17/00 G06F 3/03

Claims (12)

(57) [Claims] 1. An information processing apparatus for calculating a distance between an indicated point and a sensor based on an arrival time of an ultrasonic wave, comprising: a determination unit for determining a calibration mode; and the determination unit determines that the mode is the calibration mode. Calculation means for calculating a calibration parameter from arrival times of ultrasonic waves at a plurality of points that are arbitrarily input; and a calibration parameter stored in advance to obtain a distance between the designated point and the sensor. And an updating unit for updating the calibration parameters calculated by the calculating unit. Wherein said calculation means substitutes a group arrival time t _g and the phase arrival time t _p at a predetermined position in the predetermined arithmetic expression, calculation used to calculate the distance between the oscillation source and the sensor 2. The information processing apparatus according to claim 1, wherein a group velocity υ _g , a phase velocity υ _p , and a frequency f of parameters are obtained. Wherein said calculating means Yotsute a predetermined statistical computation by the group arrival time observed by any continuous multiple positions t _g and the phase arrival time t _p, the group velocity upsilon _g of calculation parameters, phase 2. The method according to claim 1, wherein the speed υ _p and the frequency f are obtained.
An information processing apparatus according to claim 1. Wherein said calculating means obtains the phase velocity upsilon _p of calculation parameters by substituting the group arrival time t _g and the phase arrival time t _p of a suitable predetermined positions on a predetermined arithmetic expression, any the information processing apparatus according to claim 1, wherein the determination of the group velocity upsilon _g continuous calculated pursuant parameter to a predetermined statistical computation by the group arrival time obtained t _g and the phase arrival time t _p at a plurality of positions. 5. An information processing apparatus for calculating a distance between an indicated point and a sensor based on an arrival time of an ultrasonic wave, comprising: a judging unit for judging a calibration mode; and the judging unit judges the calibration mode. Calculating means for calculating a mounting position of the sensor using a calculation parameter set from an arrival time of the ultrasonic wave at a predetermined appropriate position and calculating a deviation amount from a normal position; An information processing apparatus, comprising: updating means for updating a position correction amount of a sensor stored in advance for obtaining a distance between a point and a sensor to a displacement amount calculated by the calculating means. Wherein said calculating means, group velocity upsilon _g of the initially set calculation parameters based on the group arrival time t _g and the phase arrival time t _p of a suitable predetermined positions, phase velocity upsilon _p, 6. The information processing apparatus according to claim 5, wherein the sensor mounting position is calculated using the frequency f, and a shift amount from a normal position is calculated. 7. An information processing method in an information processing apparatus for calculating a distance between a designated point and a sensor based on an arrival time of an ultrasonic wave, the method including a calibration mode. The calibration parameters are calculated from the arrival times of the ultrasonic waves at a plurality of continuous points, and the calibration parameters stored in advance for obtaining the distance between the designated point and the sensor are updated to the calculated calibration parameters. An information processing method, comprising: The method according to claim 8, wherein the calculating step, by substituting the group arrival time t _g and the phase arrival time t _p at a predetermined position in the predetermined arithmetic expression, calculation used to calculate the distance between the oscillation source and the sensor 8. The information processing method according to claim 7, wherein a group velocity υ _g , a phase velocity υ _p , and a frequency f of parameters are obtained. 9. In the calculating step, the group velocity υ _g , the group velocity 計算_g , of the calculation parameter is obtained by a predetermined statistical calculation based on the group arrival time t _g and the phase arrival time t _p observed at arbitrary continuous positions.
8. The information processing method according to claim 7, wherein the phase velocity υ _p and the frequency f are obtained. The method according to claim 10, wherein the calculating step calculates the phase velocity upsilon _p of calculation parameters by substituting the group arrival time t _g and the phase arrival time t _p of a suitable predetermined positions on a predetermined arithmetic expression, any the information processing method according to claim 7, wherein the determination of the group velocity upsilon _g continuous calculated pursuant parameter to a predetermined statistical computation by the group arrival time obtained t _g and the phase arrival time t _p at a plurality of positions. 11. An information processing method in an information processing apparatus for calculating a distance between an indicated point and a sensor based on an arrival time of an ultrasonic wave, comprising a calibration mode, wherein a predetermined mode is set in the calibration mode. Using the calculation parameters set from the arrival time of the ultrasonic wave at the appropriate position, calculate the sensor mounting position, calculate the amount of deviation from the regular position, and obtain the distance between the indicated point and the sensor An information processing method comprising: updating a position correction amount of a sensor stored in advance to the calculated shift amount. The method according to claim 12, wherein the calculating step, the group velocity upsilon _g of the initially set calculation parameters based on the group arrival time t _g and the phase arrival time t _p of a suitable predetermined positions, phase velocity upsilon _p, 2. The method according to claim 1, further comprising calculating a mounting position of the sensor using the frequency f, and calculating an amount of deviation from a normal position.
11. The information processing method according to 11.