JP4606362B2 - Engine simulation sound generating apparatus and method - Google Patents

Description

  The present invention relates to an engine simulation sound generating apparatus and method for simulating engine sounds generated in a vehicle such as a two-wheeled vehicle or a four-wheeled vehicle equipped with an engine.

Conventionally, engine sounds that generate engine simulation sounds by actually recording mechanical sounds, exhaust sounds, and intake sounds as engine element sounds and synthesizing these recorded sounds according to engine specifications and operating conditions A sound generator is known (for example, refer to Patent Document 1).
JP 10-277263 A (No. 3-7, FIG. 1-10)

  By the way, the engine simulation sound generating device disclosed in Patent Document 1 needs to actually record mechanical sound, exhaust sound, and intake sound, so that it takes a lot of trouble to generate engine simulation sound. there were. Naturally, because the engine simulation sound changes depending on the type of engine (number of cylinders, shape), vehicle type, etc. (performance of two-wheeled vehicle, four-wheeled vehicle, muffler, etc.), in order to generate a more realistic engine simulated sound The recording work corresponding to each is required. Also, since the environment for recording machine sounds etc. is different from the environment for actually listening to engine sounds, engine simulated sounds synthesized using recorded machine sounds etc. will not necessarily be realistic sounds that reproduce engine sounds. Not exclusively. For example, it is thought that the actual engine sound is often heard while driving, but in this case the engine is loaded, so the sound recorded in the no-load (or light-load) state when the vehicle is stopped Will be different.

  The present invention has been created in view of the above points, and an object of the present invention is to provide an engine simulation sound generating apparatus and method that can generate engine simulation sound with less effort.

In order to solve the above-described problems, an engine simulation sound generator according to the present invention includes basic waveform storage means for storing basic waveform data for each cylinder corresponding to one explosion in each cylinder of the engine, and engine cylinders. Ignition condition storage means for storing the number and the ignition timing indicating the explosion timing for each cylinder as ignition conditions, engine speed setting means for setting the engine speed, and engine speed set by the engine speed setting means On the basis of the ignition conditions stored in the ignition condition storage means and the waveform synthesis means for synthesizing the basic waveform data corresponding to each cylinder, and the engine simulation sound is generated based on the waveform data synthesized by the waveform synthesis means an engine simulating sound output means, the creation of the basic waveform data stored in the basic waveform storage means, use the recorded actual explosion Rukoto Ru made without.

The engine simulation sound generation method of the present invention includes an engine rotation setting step for setting an engine rotation speed, an engine rotation speed set in the engine rotation setting step, an engine cylinder number, and an explosion timing for each cylinder. based on the ignition condition that includes the ignition timing illustrated, the waveform synthesis step of synthesizing the basic waveform data of each cylinder corresponding to each cylinder, generating an engine mock sound based on the waveform data synthesized in the waveform synthesis step The basic waveform data is created without using the recorded actual explosion sound .

  By using the engine simulation sound generating apparatus or method of the present invention, engine simulation sound can be generated by synthesizing basic waveform data based on ignition conditions, so that mechanical sound, exhaust sound, and intake sound are actually generated. There is no need to record, and engine simulation sounds can be generated with little effort.

  In addition, it is desirable to further include a noise processing means for performing a process of adding random noise to the waveform data synthesized by the waveform synthesis means described above. Alternatively, it is desirable that the engine rotation setting means described above gives fluctuations to the engine speed. As a result, it is possible to generate engine simulation sound close to actual engine sound.

  Further, it is desirable that the engine rotation setting means described above changes the engine speed in accordance with an accelerator signal indicating the accelerator opening or the throttle opening. As a result, the engine speed can be changed in accordance with the accelerator signal, and engine simulation sound linked to the changed engine speed can be generated.

  The engine rotation setting means described above preferably changes the engine speed in accordance with a shift signal indicating the gear ratio of the transmission. Thereby, the engine simulation sound can be changed in conjunction with the shift-up operation or the shift-down operation of the transmission.

  Further, it is desirable that the waveform synthesis means described above varies the peak value of the synthesized waveform in accordance with an accelerator signal indicating the accelerator opening or the throttle opening. Thereby, the output level of engine simulation sound can be changed according to the level of engine output.

  Moreover, it is desirable to further include sound quality processing means for changing the sound quality of the engine simulated sound output from the engine simulated sound output means by changing the frequency characteristic of the waveform synthesized by the waveform synthesis means described above. As a result, it is possible to consider the influence on the sound quality due to elements other than the explosion sound, such as the engine block shape and the muffler, and it is possible to generate engine simulation sounds close to actual engine sounds.

Further, the apparatus may further include an operation unit operable by the user, and an ignition condition setting unit configured to set the content of the ignition condition stored in the ignition condition storage unit according to the operation content of the user using the operation unit. desirable. Alternatively, it is desirable to further include an operation means that can be operated by the user and a basic waveform setting means for setting the basic waveform data to be stored in the basic waveform storage means in accordance with the operation contents of the user using the operation means. In addition, it is desirable to further include an operation means that can be operated by the user, and a sound quality setting means for setting the contents for changing the frequency characteristics by the sound quality processing means in accordance with the operation contents of the user using the operation means. Thereby, the engine simulation sound can be changed according to the user's operation, and the preference for each user can be reflected.

  Hereinafter, an engine simulation sound generator according to an embodiment to which the present invention is applied will be described in detail with reference to the drawings. FIG. 1 is a diagram illustrating an overall configuration of an engine simulation sound generator according to an embodiment. As shown in FIG. 1, the engine simulation sound generating apparatus 100 according to the present embodiment includes an engine rotation setting unit 10, an ignition condition setting unit 20, an ignition condition storage unit 22, a basic waveform setting unit 30, a basic waveform storage unit 32, and a waveform. The composition unit 40 includes a noise processing unit 42, a sound quality processing unit 44, a sound quality setting unit 50, a setting operation unit 60, a digital-analog converter (D / A) 70, an amplifier 72, and a speaker 74. The engine simulation sound generator 100 can be applied to, for example, a game device or a driving simulator.

  The engine speed setting unit 10 receives an accelerator signal and a shift signal, and sets the engine speed that is assumed as a target for generating engine simulation sound. The accelerator signal is a signal indicating the accelerator opening of the vehicle. In the case of a two-wheeled vehicle, since it is often expressed as “throttle” instead of “accelerator” of a four-wheeled vehicle or the like, the accelerator opening can be replaced with the throttle opening. In the present embodiment, the throttle signal indicating the throttle opening is also collectively referred to as an “accelerator signal”. The shift signal indicates a gear ratio of a vehicle transmission (manual transmission or automatic transmission). A case where the gear ratio continuously changes is also conceivable.

  The ignition condition setting unit 20 sets the content of the engine ignition condition in accordance with a user operation instruction. For example, as the ignition condition, the number of cylinders of the engine and an ignition timing indicating an explosion timing for each cylinder are set.

  FIG. 2 is a diagram showing an ignition condition setting screen. This setting screen is created and displayed by a control unit (not shown) that controls the engine simulation sound generator 100 as a whole. The user can set the ignition condition by operating the setting operation unit 60 and inputting necessary items in the setting screen. In the ignition condition setting screen shown in FIG. 2, a check box (a square frame on the reading side of the numbers 1 to 12) for setting the number of cylinders in a range of up to 12 cylinders and ignition timings corresponding to the respective cylinders are displayed. An input field for input is provided. For example, in the case of a four-cylinder engine, check boxes corresponding to each of 1 to 4 may be checked with a pointing device provided in the setting operation unit 60 (the check box changes color, X mark). In addition, an ignition timing for each cylinder expressed by an angle is input to the input frame. In the case of a typical four-stroke engine, one explosion process is included corresponding to each cylinder while the engine rotates twice, so that the input frame corresponding to each of 1 to 4 includes 0 to 720 °. The ignition timing is input within the range. This input is also performed using the setting operation unit 60. When the setting operation unit 60 has a numeric keypad, the ignition timing value can be directly input. When the setting operation unit 60 is provided with two or more arrow keys, a joystick, or the like, the ignition timing value may be increased or decreased in a predetermined direction to display a desired value. In the setting screen shown in FIG. 2, it is possible to set ignition timings for up to 12 cylinders. However, for engines with more cylinders, the range of 1 to 12 is expanded to increase the ignition timings for more cylinders. Can be entered. The ignition condition set by the ignition condition setting unit 20 is stored in the ignition condition storage unit 22.

  The basic waveform setting unit 30 sets the shape of the basic waveform corresponding to one explosion in each cylinder in accordance with a user operation instruction. The basic waveform may be recorded as an actual explosive sound, but more simply, an appropriate shape may be created while viewing the setting screen.

  FIG. 3 is a diagram showing a basic waveform setting screen. Similar to the ignition condition setting screen, this setting screen is created and displayed by the control unit that controls the engine simulation sound generator 100 as a whole. The user can operate the setting operation unit 60 to define a basic waveform having an arbitrary shape in the setting screen. In the example shown in FIG. 3, a typical basic waveform is shown in advance, and the user can arbitrarily change the shape of the basic waveform by operating the setting operation unit 60. A basic waveform having an arbitrary shape may be defined by operating a pointing device or the like provided in the setting operation unit 60 to draw an arbitrary locus. In addition, when the explosion sound waveform actually recorded is used as the basic waveform, the setting screen shown in FIG. 3 is not necessarily displayed. Note that the actual explosion sound does not have a simple waveform in which the signal level suddenly rises at the time of explosion as shown in FIG. 3 and then monotonously decreases, but the basic waveform has a simple shape as shown in FIG. It is confirmed that an engine simulation sound that is close to the actual engine sound is generated even when using. The basic waveform data set by the basic waveform setting unit 30 is stored in the basic waveform storage unit 32.

  The waveform synthesis unit 40 synthesizes basic waveform data corresponding to each cylinder based on the engine speed set by the engine rotation setting unit 10 and the ignition condition stored in the ignition condition storage unit 22, Generate a waveform of the entire explosion sound (engine sound). Based on the engine speed and ignition conditions, the time interval for synthesizing the basic waveform corresponding to each cylinder is determined. By overlapping the basic waveform at this determined time interval, the waveform for the explosion sound of the entire engine Can be generated. An accelerator signal is input to the waveform synthesizer 40. If the accelerator opening is large and the fuel sucked into each cylinder of the engine increases, the explosion sound increases accordingly. In order to simulate this phenomenon, the waveform synthesizer 40 varies the peak value of the synthesized waveform in accordance with the accelerator signal. Thus, the peak value of the composite waveform is set so that a loud engine sound is obtained when the accelerator opening is large, and conversely, a small engine sound is obtained when the accelerator opening is small.

  The noise processing unit 42 performs processing for adding random noise to the waveform data synthesized by the waveform synthesis unit 40. The sound quality processing unit 44 is output from the engine simulation sound generator 100 by performing a filtering process for changing the frequency characteristics of the waveform data after being synthesized by the waveform synthesis unit 40 and added with random noise by the noise processing unit 42. Change the sound quality of the engine simulation sound. For example, it is formed by an FIR filter, and the frequency specification can be changed by changing the filter coefficient. The sound quality setting unit 50 sets contents for changing the frequency characteristics by the sound quality processing unit 44 in accordance with a user operation instruction.

  FIG. 4 is a diagram illustrating a frequency characteristic setting screen. This setting screen shows the current frequency characteristics. The horizontal axis indicates the frequency f, and the vertical axis indicates the signal level in each frequency band. This frequency characteristic is not the frequency characteristic of the synthesized waveform but the frequency characteristic (filter characteristic) of the filter when the synthesized waveform is passed through the filter. In the example shown in FIG. 4, the case where the frequency characteristic corresponding to an audible frequency band is flat is shown. The user can specify each frequency band indicated by A to G and vary the corresponding signal level. The setting of the frequency band and the variable operation of the signal level can be performed using the setting operation unit 60.

  The digital-analog converter 70 converts the synthesized waveform data after the frequency characteristic variable output from the sound quality processing unit 44 into an analog sound signal. This sound signal is amplified by the amplifier 72 and output from the speaker 74.

  The basic waveform storage unit 32 described above is the basic waveform storage unit, the ignition condition storage unit 22 is the ignition condition storage unit, the engine rotation setting unit 10 is the engine rotation setting unit, the waveform synthesis unit 40 is the waveform synthesis unit, and the digital- The analog converter 70, amplifier 72, and speaker 74 correspond to engine simulation sound output means, respectively. The noise processing unit 42 is a noise processing unit, the sound quality processing unit 44 is a sound quality processing unit, the setting operation unit 60 is an operation unit, the ignition condition setting unit 20 is an ignition condition setting unit, and the basic waveform setting unit 30 is a basic operation. The sound quality setting unit 50 corresponds to the waveform setting means, and corresponds to the sound quality setting means. Further, the operation by the engine rotation setting unit 10 is the operation of the engine rotation setting step, the operation by the waveform synthesis unit 40 is the operation of the waveform synthesis step, and the operations by the digital-analog converter 70, the amplifier 72, and the speaker 74 are engine simulation sounds. Each corresponds to the operation of the output step.

  The engine simulation sound generating apparatus 100 of the present embodiment has such a configuration, and the operation thereof will be described next. FIG. 5 is a flowchart showing an operation procedure until the synthesized waveform data is generated and stored. FIG. 6 is a flowchart showing an operation procedure until the stored synthetic waveform data is read and the engine simulation sound is output.

  When the engine speed is determined by the engine rotation setting unit 10 (step 100), the waveform synthesis unit 40 determines the basic waveform extraction range corresponding to each cylinder of the engine (step 101). For example, when the engine speed is determined, the time for which the crankshaft of each cylinder rotates once is determined, and therefore the portion corresponding to this time is extracted from the basic waveform. Next, the waveform synthesis unit 40 synthesizes a partially extracted basic waveform in accordance with the ignition timing of each cylinder stored in the ignition condition storage unit 22 (step 102). For example, the value of the composite waveform is calculated at time intervals corresponding to a predetermined sampling frequency. The noise processing unit 42 adds random noise to the composite waveform data calculated in this way (step 103). The combined waveform data to which the random noise is added is stored in a first-in first-out storage unit (not shown) in time-series order (step 104). Such synthetic waveform data generation operation is repeated.

  In parallel with the above-described generation and storage operations of the synthesized waveform data, the sound quality processing unit 44 reads the stored synthesized waveform data (step 200) and performs a filtering process corresponding to the frequency characteristics set by the sound quality setting unit 50. (Step 201). The combined waveform data after the filtering process is converted into an analog sound signal by the digital-analog converter 70 (step 202), amplified by the amplifier 72, and engine simulated sound is output from the speaker 74 (step 203). Such engine simulation sound generation and output operations are repeated.

  As described above, the engine simulation sound generation apparatus 100 according to the present embodiment can generate engine simulation sound by synthesizing basic waveform data based on the ignition conditions of the engine. There is no need to record the intake sound, and the engine simulation sound can be generated with little effort. Further, by adding random noise after waveform synthesis, it is possible to generate engine simulation sound close to actual engine sound. Further, by changing the engine speed in accordance with the accelerator signal indicating the accelerator opening (or throttle opening), it is possible to generate engine simulation sound that is linked to the changed engine speed. Further, by changing the engine speed according to the shift signal indicating the gear ratio of the transmission, the engine simulation sound can be changed in conjunction with the shift-up operation or the shift-down operation of the transmission.

  Further, by changing the peak value of the composite waveform according to the accelerator signal, the output level of the engine simulation sound can be changed according to the level of the engine output. By changing the frequency characteristics of the synthesized waveform and changing the sound quality of the engine simulation sound, it is possible to consider the effects on the sound quality due to factors other than explosion sounds, such as the shape of the engine block and the muffler. The engine simulation sound close to the sound can be generated.

  In addition, by setting the ignition characteristics, the basic waveform, and the frequency characteristics when performing the filtering process by the sound quality processing unit 44 according to the user's operation, the engine simulated sound can be changed, and the preference for each user can be changed. It can be reflected.

  In addition, this invention is not limited to the said embodiment, A various deformation | transformation implementation is possible within the range of the summary of this invention. For example, in the above-described embodiment, the engine speed setting unit 10 determines the engine speed based on the accelerator signal or the shift signal. However, the engine speed setting unit 10 increases or decreases the engine speed at a predetermined frequency to cause fluctuations. You may make it give. This makes it possible to generate engine simulation sounds that are closer to actual engine sounds.

  In the above-described embodiment, the user can arbitrarily set the ignition condition, the basic waveform, and the frequency characteristic of the filtering process by operating the setting operation unit 60. However, the game device or the driving simulator When the configuration of the present invention is used for generating engine simulation sound such as the above, the contents of the ignition condition, basic waveform, and frequency characteristics of filtering processing may be fixed. In this case, some or all of the ignition condition setting unit 20, the basic waveform setting unit 30, and the sound quality setting unit 50 shown in FIG. 1 may be omitted.

  In the above-described embodiment, the combined waveform data after adding random noise is temporarily stored, and after that, the stored combined waveform data is read out and then the filtering process is performed. The order of storing / reading and filtering processing may be changed. That is, the synthesized waveform data after the filtering process by the sound quality processing unit 44 is stored, and the stored synthesized waveform data is read out in time series and input to the digital-analog converter 70. Good. Alternatively, the data immediately after the waveform synthesis by the waveform synthesis unit 40 may be stored, and the stored synthesized waveform data may be read in time series in order to perform random noise addition and filtering processing.

  In the above-described embodiment, after the waveform synthesis is performed, the synthesized waveform data is passed through one digital-analog converter 70 to generate an analog engine simulation sound. However, a plurality of cylinders constituting the engine are grouped into a plurality of groups. Divide and synthesize the waveform for each group (there is no need to synthesize the waveform if one cylinder corresponds to one group, the basic waveform itself is used). -You may make it pass an analog converter. In this case, an analog sound signal output from each of the plurality of digital-analog converters may be synthesized, amplified by the amplifier 72, and output from the speaker 74.

It is a figure showing the whole engine simulation sound generating device composition of one embodiment. It is a figure which shows the setting screen of ignition conditions. It is a figure which shows the setting screen of a basic waveform. It is a figure which shows the setting screen of a frequency characteristic. It is a flowchart which shows the operation | movement procedure until it produces | generates and stores synthetic | combination waveform data. It is a flowchart which shows the operation | movement procedure until it reads the stored synthetic | combination waveform data and outputs engine simulation sound.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Engine speed setting part 20 Ignition condition setting part 22 Ignition condition storage part 30 Basic waveform setting part 32 Basic waveform storage part 40 Waveform synthesis part 42 Noise processing part 44 Sound quality processing part 50 Sound quality setting part 60 Setting operation part 70 Digital-analog conversion (D / A)
72 Amplifier 74 Speaker 100 Simulated engine generator

Claims (11)

Basic waveform storage means for storing basic waveform data for each cylinder corresponding to one explosion in each cylinder of the engine;
Ignition condition storage means for storing the number of cylinders of the engine and the ignition timing indicating the explosion timing for each cylinder as ignition conditions;
Engine speed setting means for setting the engine speed;
Waveform synthesizing means for synthesizing the basic waveform data corresponding to each cylinder based on the engine speed set by the engine rotation setting means and the ignition condition stored in the ignition condition storage means;
Engine simulation sound output means for generating engine simulation sound based on the waveform data synthesized by the waveform synthesis means;
Wherein the creation of the basic waveform data stored in the basic waveform storage means, engine simulated sound generating device according to claim Rukoto performed without using the recorded actual explosion. In claim 1,
An engine simulation sound generating apparatus, further comprising noise processing means for performing processing for adding random noise to the waveform data synthesized by the waveform synthesis means. In claim 1 or 2,
An engine simulation sound generating apparatus characterized in that the engine rotation setting means gives fluctuations to the engine speed. In claim 1 or 2,
The engine rotation setting means changes the engine rotation speed in accordance with an accelerator signal indicating an accelerator opening or a throttle opening. In claim 3 or 4,
The engine rotation setting means changes the engine rotation speed in accordance with a shift signal indicating a gear ratio of the transmission. In claim 1 or 2,
The engine-synthesized sound generator according to claim 1, wherein the waveform synthesizing unit varies a peak value of the synthesized waveform in accordance with an accelerator signal indicating an accelerator opening or a throttle opening. In any one of Claims 1-6,
The engine simulation sound further comprising sound quality processing means for changing the sound quality of the engine simulation sound output from the engine simulation sound output means by varying the frequency characteristic of the waveform synthesized by the waveform synthesis means. Generator. In any one of Claims 1-7,
Operation means that can be operated by the user;
Ignition condition setting means for setting the contents of the ignition condition stored in the ignition condition storage means according to the operation contents of the user using the operation means;
An engine simulation sound generator characterized by further comprising: In any one of Claims 1-7,
Operation means that can be operated by the user;
An engine simulation sound generating apparatus, further comprising basic waveform setting means for setting the basic waveform data stored in the basic waveform storage means in accordance with a user's operation content using the operation means. In claim 7,
Operation means that can be operated by the user;
An engine simulation sound generating apparatus, further comprising sound quality setting means for setting contents for changing frequency characteristics by the sound quality processing means in accordance with the user's operation contents using the operation means. An engine speed setting step for setting the engine speed;
Based on the engine speed set in the engine speed setting step, and the ignition condition including the number of cylinders of the engine and the ignition timing indicating the explosion timing for each cylinder, the basic for each cylinder corresponding to each cylinder A waveform synthesis step for synthesizing waveform data;
Engine simulation sound output step for generating engine simulation sound based on the waveform data synthesized in the waveform synthesis step;
Have a, the creation of the basic waveform data, engine simulated sound generating method comprising Rukoto performed without using the recorded actual explosion.

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