JP2017161858A - Sound production controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique capable of more accurately detecting a trigger in sound production control of a performance sound of a percussion instrument by an electronic sound source such as an MIDI sound source.SOLUTION: A sound production controller for an electronic percussion instrument comprises: movement detection means; vibration detection means; sound production control means; and threshold update means. The movement detection means detects a movement of an impact body such as a stick, and outputs a signal indicating the detection result. The vibration detection means detects vibration generated on a percussion surface, and outputs a signal expressing a wave form of the vibration. The sound production control means causes an electronic sound source to produce a sound with a fact that, an amplitude of an envelope of the output signal of the vibration detection means exceeds a first threshold, as a momentum, in a silent state, and causes the electronic sound source to stop a sound production, with a fact that, the amplitude becomes lower than a second threshold in a sound production state. The threshold update means updates the second threshold to a larger value when it is determined that, at least one impact body is moving to a percussion surface in the sound production state.SELECTED DRAWING: Figure 1

Description

  The present invention relates to sound generation control of percussion instrument performance sounds using an electronic sound source such as a MIDI sound source.

  In general, an electronic percussion instrument such as an electronic drum has a sensor that detects vibration generated on a hitting surface such as a pad by hitting (hereinafter referred to as an attack) and outputs an audio signal. Sound control in electronic percussion instruments is realized as follows. The electronic percussion instrument transitions from the sound emission stop state to the sound emission state by giving a note-on signal to a MIDI sound source or the like when the amplitude of the envelope of the output signal of the sensor exceeds a predetermined threshold in the sound emission stop state. In the sound emission state, when the amplitude of the envelope falls below the threshold value, the sound emission state is changed to the sound emission stop state. As an example of the prior art relating to this type of sound generation control technique, there is a technique disclosed in Patent Document 1.

JP 2010-271428 A

  In this type of sound generation control technique, various problems occur due to a trigger detection error. For example, this type of sound generation control technique has a problem that sound omission (missing note-on) due to attack detection omission is likely to occur when the hitting surface is continuously hit. This is because when the hitting surface is continuously hit, a situation in which the amplitude of the envelope of the output signal of the sensor tends to increase before it falls below the threshold is likely to occur. If the amplitude of the envelope of the sensor output signal starts to increase before falling below the threshold, a transition from the sound emission state to the sound emission stop state does not occur, and an event that triggers the output of the next note-on signal (i.e., This is because the amplitude of the envelope of the sensor output signal does not exceed the threshold value in the silent state.

  This type of sound generation control technique is also used in a mute performance in which a raw drum is muted and played, but the above-mentioned sound omission may become more noticeable in a live drum mute performance. The mute performance refers to a performance mode in which sound generation of an electronic sound source is controlled according to the vibration while muting the head of the raw drum to suppress the vibration. According to such a performance mode, the performer plays the live drum while wearing the headphones, and gives the output signal of the electronic sound source to the headphones, so that the performance of playing the live drum is not disturbed. It can be performed. The reason why the above-mentioned sound omission becomes more noticeable in the mute performance of a live drum is that the pads of the electronic drum are often made of a material having a large vibration attenuation, such as urethane foam, and the frequency of omission of sound is relatively low. This is because the vibration of the raw drum head is more gradual.

  Further, this type of sound generation control technique has a problem that a delay (hereinafter referred to as latency) is likely to occur when a note-on signal is supplied to a MIDI sound source or the like. The reason for this is as follows. Normally, when giving a note-on signal to a MIDI sound source or the like, information indicating the intensity of sound, that is, velocity is added to the note-on signal. The velocity is determined based on the slope of the envelope at the time when the amplitude of the envelope of the sensor output signal exceeds a predetermined threshold. More specifically, the inclination is expressed as a ratio of a change in the amplitude of the envelope at a time point when a value in the vicinity of the threshold value (hereinafter, a predetermined value) is exceeded with respect to an amplitude value of the envelope at a time point when the predetermined threshold value is exceeded. expressed. In this type of sound generation control technique, when a small value is set as the predetermined value, there is a possibility that an erroneous determination due to noise may occur in determining whether or not the amplitude of the envelope exceeds the value. For this reason, a large value is usually set as the predetermined value. However, in this case, after the amplitude of the envelope exceeds a predetermined threshold, it takes a long time to determine that the amplitude of the envelope exceeds the predetermined value. As a result, it takes a long time to calculate the velocity after the attack occurs, and the above problem occurs.

  The present invention has been made in view of the above problems, and provides a technique that makes it possible to detect a trigger with higher accuracy than before in the sound generation control of percussion instrument performance sounds using an electronic sound source such as a MIDI sound source. For the purpose.

  In order to solve the above-mentioned problems, the present invention detects motion of one or a plurality of percussion bodies for striking the percussion surface of a percussion instrument, and outputs a signal indicating the detection result, and one or a plurality of percussion objects A vibration detection unit that detects vibration generated on the hitting surface in response to a hit by the hitting body and outputs a signal representing a waveform of the vibration, and an amplitude of an envelope of an output signal of the vibration detection unit exceeds a first threshold. In response to this, a transition is made to a sounding state and sound generation is instructed to the electronic sound source, and when the amplitude of the envelope falls below the second threshold value, a soundless state is entered and the electronic sound source is instructed to stop sounding. When the output signals of the sound generation control means and the motion detection means are analyzed and it is determined that at least one striking body is moving toward the hitting surface in the sound generation state, the second threshold value is set to a larger value. Sound generation control apparatus comprising: a threshold updating means for updating, and provides.

  A specific example of an electronic sound source is a MIDI sound source. As a specific example of a sound generation instruction (sound generation control signal) when a MIDI sound source is used as an electronic sound source, a signal or note for instructing the MIDI sound source to turn on a note. For example, a signal that indicates turning off may be used. Specific examples of the striking body include a player's fingertip and stick. According to the present invention, when it is determined that at least one impacting body is moving toward the percussion surface of the percussion instrument in the sounding state, it is determined whether or not a transition from the sounding state to the silent state is generated. The second reference threshold value is updated to a larger value. When hitting the hitting surface repeatedly, the hitting body moves toward the hitting surface of the percussion instrument in the sounding state. Therefore, when consecutive hitting occurs, the second threshold value is updated to a larger value, Even if the vibration generated on the hitting surface is not sufficiently attenuated by the preceding hit, the transition from the sounding state to the silent state occurs, and the electronic sound source changes from the sound emitting state to the sound emitting stop state, and the above-mentioned sound omission occurs. Is prevented. As described above, according to the present invention, it is possible to prevent sound omission due to repeated hits from occurring in sound generation control in which a percussion instrument performance sound is generated by an electronic sound source such as a MIDI sound source.

  In a more preferred aspect, the apparatus has velocity calculation means for calculating a velocity based on the amplitude when the amplitude of the envelope exceeds a first threshold, and the sound generation control means includes the velocity calculated by the velocity calculation means. Is added to the pronunciation instruction, and the threshold value updating means updates the first threshold value to a smaller value when it is determined that at least one percussion body is moving toward the percussion surface of the percussion instrument. Features. According to such an aspect, since a small value is set for the first threshold value, it is necessary to detect the amplitude that exceeds the threshold value in determining whether or not the amplitude of the envelope exceeds the predetermined threshold value. Time is shortened. Therefore, it is possible to prevent the occurrence of latency when a note-on signal is supplied to a MIDI sound source or the like.

  In another preferred embodiment, the output signal of the vibration detection means is subjected to interpolation processing, envelope extraction means for outputting envelope data representing the envelope, and the output signal of the motion detection means is analyzed, and the at least one impacting body Is further provided with interpolation speed updating means for updating the interpolation speed in the envelope extraction means to a smaller value when it is determined that the movement is toward the percussion surface of the percussion instrument. According to such an aspect, since the probability that noise is included in the envelope waveform is reduced, even if a small value is set for the first threshold, it is possible to determine whether the envelope amplitude exceeds a predetermined value. It is possible to prevent an erroneous determination due to the occurrence of the error.

  In a further preferred aspect, the sound generation control device of the present invention comprises a recording means for recording an output signal output from the motion detection means or a feature amount indicating the feature of the output signal while the impacting body is moving toward the hitting surface. The threshold update means is characterized in that it is determined whether or not at least one striking body is moving toward the hitting surface in the sounding state with reference to the recorded content of the recording means. According to such an aspect, by recording a performance action peculiar to the performer prior to the performance of the percussion instrument, sound omission caused by repeated strikes can be surely prevented while taking into account the individual performance characteristics of the performer. It becomes possible to do.

It is a block diagram which shows the structural example of the sound generation control apparatus 1 which is 1st Embodiment of this invention. It is a block diagram which shows the structural example of 1 A of sound generation control apparatuses which are 2nd Embodiment of this invention. It is a figure which shows the structure of the envelope extraction part 24b in the same embodiment. In the same embodiment, it is a figure which shows the detail of the various data which change according to the envelope waveform which the envelope extraction part 24b produces | generates the envelope waveform B and the said envelope data B change. In the same embodiment, it is a flowchart which shows the content of the well-known trigger detection process. In the same embodiment, it is a figure which shows a mode that noise is superimposed on the envelope waveform which the envelope data B which the envelope extraction part 24b produces | generates represents. In the same embodiment, it is a flowchart which shows the content of the threshold value update process which the threshold value update part 26c performs. In the same embodiment, it is a flowchart which shows the content of the interpolation speed update process which the interpolation speed update part 26d performs. In the same embodiment, it is a figure which shows the detail of the various data which change according to the envelope waveform which the envelope extraction part 24b produces | generates the envelope waveform B and the said envelope data B change.

<First Embodiment>
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing a configuration example of a sound generation control device 1 according to the first embodiment of the present invention. The sound generation control device 1 is for realizing a mute performance of a percussion instrument 2 such as a raw drum, and is connected to a sound system 3. The sound system 3 includes an electronic sound source and a speaker that emits sound in accordance with an audio signal output from the electronic sound source. In the present embodiment, a MIDI sound source is adopted as the electronic sound source.

  The sound generation control device 1 is a device that outputs a sound generation control signal to the sound system 3 in accordance with a performance operation with respect to the percussion instrument 2. The performance operation with respect to the percussion instrument 2 refers to the operation of hitting the percussion surface of the percussion instrument 2 with an impacting body such as a stick. This is the MIDI signal to be used. The sound generation control device 1 according to the present embodiment is configured so that no sound is lost even when a performance operation is performed such that the percussion surface of the percussion instrument 2 is repeatedly hit. There are features. More specifically, the sound generation control device 1 includes a motion detection means 10, a vibration detection means 12, a sound generation control means 14, and a threshold update means 16, as shown in FIG. The role and specific configuration of each means constituting the sound generation control device 1 are as follows.

  The motion detection means 10 detects the movement of the hitting body for hitting the hitting surface of the percussion instrument 2 and outputs data indicating the detection result to the threshold update means 16. As described above, in the present embodiment, a stick is used as a hitting body for hitting the hitting surface of the percussion instrument 2. The motion detection means 10 is a three-axis acceleration sensor 10a built in the stick, and A / D conversion is performed on the output signal of the acceleration sensor 10a to convert it into digital waveform data, which is supplied to the threshold update means 16 D converter 10b. The acceleration sensor 10a periodically repeats the process of detecting the acceleration generated on the stick in accordance with the performance operation of the performer and outputting an analog signal indicating the magnitude and direction of the acceleration along the three axes.

  The vibration detecting means 12 detects the vibration generated on the percussion surface of the percussion instrument 2 in accordance with the player's performance of the percussion instrument 2, and the signal representing the vibration waveform falls within the range of 0 to 1. So that the output is normalized. As shown in FIG. 1, the vibration detection means 12 is attached to the hitting surface of the percussion instrument 2, and the vibration sensor 12 a periodically repeats the process of outputting an analog signal indicating the waveform of the vibration generated on the hitting surface. And an A / D converter 12b that performs A / D conversion on the output signal of the sensor 12a to convert it into digital waveform data and supplies it to the sound generation control means 14.

  The sound generation control unit 14 performs sound generation control of the sound system 3 according to the output data of the vibration detection unit 12. The sound generation control means 14 performs the following processing in each of the sound emission stop state where sound emission (sound generation) is not performed by the sound system 3 and the sound emission state where the sound emission is performed. In the sound emission stop state, the sound generation control unit 14 changes the internal state of the sound generation control device 1 to the silent state when the amplitude of the envelope of the waveform represented by the output data of the vibration detection unit 12 exceeds the first threshold value. , The sound generation instruction signal is output to the sound system 3 to generate sound. On the other hand, in the sound emission state, the sound generation control unit 14 causes the internal state to transition from the sound generation state to the silence state when the amplitude falls below the second threshold value, and a stop instruction for instructing the sound generation to stop. The signal is output to the sound system 3 and the sound generation of the sound system 3 is stopped. In order to fulfill such a role, the sound generation control means 14 includes a storage unit 14a, an envelope extraction unit 14b, a threshold value determination unit 14c, and a sound generation control signal generation unit 14d as shown in FIG.

The storage unit 14a includes a volatile memory such as a RAM (Random Access Memory) and a flash ROM (Read
Non-volatile memory such as “Only Memory”. The volatile memory stores state data S representing the internal state of the sound generation control device 1 and threshold data Th1 and Th2 representing the first and second threshold values described above. In the nonvolatile memory, initial values of the state data S and the threshold data Th1 and Th2 are stored. In the present embodiment, a value representing a silent state is stored in the nonvolatile memory as an initial value of the state data S, and a value Th0 representing each initial value of the threshold data Th1 and Th2 is stored. Each data representing these initial values is read from the nonvolatile memory by the threshold value determination unit 14c when the sounding control device 1 is turned on, and is stored in the volatile memory as the state data S and threshold value data Th1 and Th2.

  The envelope extraction unit 14b is, for example, a full-wave rectifier circuit and a low-pass filter. The envelope extraction unit 14b generates envelope data representing an envelope (envelope) of the waveform represented by the output data from the output data of the vibration detection unit 12, and sends the envelope data to the threshold determination unit 14c. give. The threshold determination unit 14c executes different processes depending on whether the internal state of the sound generation control device 1 is a silent state or a sound generation state. When the internal state of the sound generation control device 1 is a silent state, the threshold value determination unit 14c receives the envelope data and has the amplitude value represented by the envelope data exceed the first threshold value represented by the threshold data th1? If the determination result is Yes, the internal state is updated from the silent state to the sounding state, and the sounding control signal generating unit 14d is instructed to generate the sounding instruction signal. The sound generation control signal generation unit 14d generates a sound generation instruction signal and gives it to the sound system 3 under the control of the threshold value determination unit 14c. On the other hand, when the internal state of the sound generation control device 1 is the sound generation state, the threshold value determination unit 14c receives the second envelope data, and the amplitude value represented by the envelope data represents the second value represented by the threshold data th2. If the determination result is Yes, the internal state is updated from the sounding state to the silent state, and the sounding control signal generation unit 14d is instructed to generate a stop instruction signal. The sound generation control signal generation unit 14d generates a stop instruction signal and gives it to the sound system 3 under the control of the threshold determination unit 14c.

  The threshold update unit 16 analyzes the output data of the motion detection unit 10 and sets the second threshold as an initial value when it is determined that at least one percussion body is moving toward the percussion surface of the percussion instrument 2 in the sounding state. Update to a value greater than the value. In order to fulfill such a role, the threshold update unit 16 includes a motion detection unit 16a, an operation determination unit 16b, and a threshold update unit 16c, as shown in FIG. The role of each part is as follows.

  The motion detection unit 16a calculates the magnitude of the speed obtained by integrating the acceleration represented by the output data of the motion detection means 10, and only when the calculated value exceeds a predetermined threshold value, the motion detection unit 16b. As described above, the acceleration sensor included in the motion detection means 10 is a triaxial acceleration sensor, and the output data is data representing the magnitude and direction of the velocity component obtained by integrating the acceleration along each axis. The motion detection unit 16a calculates the sum of squares of each speed component (or the square root of the sum of the squares), and gives the output data to the motion determination unit 16b only when the calculation result exceeds the threshold value. The reason for providing such a motion detection unit 16a is to avoid erroneously determining that a fine movement of the impacting body that is unrelated to the performance operation is a performance operation.

The motion determination unit 16b refers to the state data S stored in the storage unit 14a and the output data provided from the motion detection unit 16a, the former indicates a sound generation state, and the vertical speed indicated by the latter is It is determined whether or not it is a positive value (that is, vertically downward). Then, when the determination result is “Yes”, the operation determination unit 16b provides the threshold update unit 16c with a control signal instructing the update of the second threshold. The threshold update unit 16c is triggered by the reception of this control signal to update the threshold data Th2 stored in the volatile memory of the storage unit 14a to a value larger than the initial value Th0 by a predetermined amount Δ (Δ> 0). . It should be noted that the second threshold update amount Δ may be appropriately tested and set to a suitable value (that is, a value that can reliably prevent sound leakage during repeated hits).
The above is the configuration of the sound generation control device 1.

  When the player performs a continuous hitting of the percussion surface of the percussion instrument 2 using a stick, the internal state of the sound generation control device 1 is in a sounding state at the time of the first hitting, and the stick is used for a hit following the hitting. At the stage of swinging down, the determination result of the operation determination unit 16b is “Yes”, and the second threshold th2 is updated to a value larger by a predetermined amount Δ than the initial value th0. Since the second threshold th2 is updated to a value larger than the initial value th0 by a predetermined amount Δ, a transition from the sound generation state to the silence state is likely to occur. For this reason, if the amplitude value represented by the envelope data output from the envelope detector 14b falls below the second threshold value (ie, th0 + Δ), the internal state of the sound generation control device 1 is updated to the silent state, and the above-described subsequent hitting causes the above-described impact to occur. A sound generation instruction signal is output to the sound system 3 when the amplitude value exceeds the first threshold value.

  As described above, according to the present embodiment, it is possible to avoid the occurrence of sound removal due to the hitting of the hitting surface in the sound generation control of the percussion instrument performance sound by the electronic sound source. In the present embodiment, an example of application to sound generation control during mute performance of a live drum has been described. However, the sound generation control device 1 is incorporated in an electronic percussion instrument such as an electronic drum, and the sound generation control device 1 is used for sound generation control in the electronic percussion instrument. Of course, it may be applied.

<B: Second Embodiment>
FIG. 2 is a block diagram illustrating a configuration example of the sound generation control device 1A according to the second embodiment of the present invention. The sound generation control device 1A of the second embodiment is configured to be able to quickly output a sound generation instruction signal to which velocity has been added after exceeding the first threshold value Th1. There are features. As is clear from the comparison between FIG. 2 and FIG. 1, the sound generation control device 1 </ b> A has a sound generation control means 24 instead of the sound generation control means 14, and has a threshold update means 26 instead of the threshold update means 16. However, the sound generation control device 1 is different.

  The sound generation control means 24 according to the second embodiment performs sound generation control on the storage unit 24a instead of the storage unit 14a, the envelope extraction unit 24b instead of the envelope extraction unit 14b, and the threshold value determination unit 24c instead of the threshold value determination unit 14c. It differs from the sound generation control means 14 in that it has a sound generation control signal generation section 24d in place of the signal generation section 14d, and further has a velocity calculation section 24e in addition to the above-mentioned sections. The envelope extraction unit 24b is, for example, an envelope follower, performs interpolation processing on the output data of the vibration detection means 12, generates envelope data representing the waveform envelope represented by the output data, and supplies the envelope data to the threshold determination unit 24c.

  FIG. 3 is a diagram illustrating a configuration of the envelope extraction unit 24b. As illustrated in FIG. 3, the envelope extraction unit 24 b includes a full wave rectification unit 241 and an interpolation unit 242. The full wave rectification unit 241 performs full wave rectification on the output data of the vibration detection unit 12 and outputs envelope data representing the envelope waveform to the interpolation unit 242. The interpolation unit 242 includes amplification units 2421 and 2422, addition units 2423 and 2424, and a delay processing unit 2425, and performs an interpolation process on the envelope data output from the full wave rectification unit 241.

  The amplifying unit 2421 multiplies the amplitude value of the envelope data received from the full-wave rectifying unit 241 by α (0 <α ≦ 1), and outputs the amplified envelope data to the adding unit 2423. The delay processing unit 2425 performs a delay process for one sample on the envelope data output from the adding unit 2423, and provides the envelope data after the delay processing to the amplifying unit 2422, the adding unit 2424, and the threshold value determining unit 24c. The amplifying unit 2422 multiplies the amplitude value of the envelope data output from the delay processing unit 2425 by (1−α), and outputs the amplified envelope data to the adding unit 2423. The adding unit 2423 adds the envelope data output from the amplifying unit 2421 and the amplifying unit 2422 and gives the calculation result to the delay processing unit 2425. That is, the envelope data output from the amplifying unit 2422 to the adding unit 2423 corresponds to the envelope data one sample before the envelope data output from the amplifying unit 2421 to the adding unit 2423. Accordingly, it is possible to generate envelope data representing a smooth envelope waveform by mixing the envelope data at a ratio corresponding to α. Hereinafter, each of the sample data constituting the envelope data generated by the interpolation unit 242 is referred to as “envelope data B”. Here, α is an index (interpolation coefficient) indicating the degree of smoothness of the envelope waveform represented by the envelope data B, and the closer α is to 1, the more one sample of the envelope data input to the adder 2423 The ratio of the envelope data is reduced, and the effect of the interpolation process is reduced. On the other hand, as α approaches 0, the ratio of envelope data one sample before the envelope data input to the adder 2423 increases, and the effect of the interpolation process increases. Therefore, the effect of the interpolation process can be optimized by appropriately setting the value of the interpolation coefficient α.

  In the present embodiment, a different value is set as the interpolation coefficient α at the time of attack and at the time of release. More specifically, as shown in FIG. 3, the envelope data output from the full-wave rectifying unit 241 and the envelope data output from the delay processing unit 2425 are output to the adding unit 2424, and the former envelope data and the latter Envelope data (data obtained by multiplying the amplitude value by -1) is added. When the amplitude value of the envelope data output from the adder 2424 increases, that is, when an attack is performed, the sign of the addition result is positive, and an interpolation coefficient (interpolation coefficient αi) at the time of attack is set. On the other hand, when the amplitude value of the envelope data output from the adding unit 2424 is lowered, that is, at the time of release, the sign of the addition result is negative, and the interpolation coefficient (interpolation coefficient αd) at the time of release is set.

  In the volatile memory of the storage unit 24a, threshold data Th1 representing a first threshold, an increase flag IncFlag, a minimum value Bmin, a coefficient Bmul, a maximum value Bmax, a trigger detection flag TrigFlag, an attack interpolation speed AtkItpSpeed, and a release interpolation speed RelItSpeed Stored. The initial value of each data is stored in the nonvolatile memory. The increase flag IncFlag is a flag indicating whether or not the amplitude value represented by the envelope data B is in an increasing state until immediately before the trigger is detected. The minimum value Bmin is data indicating the minimum value of the envelope data B. The coefficient Bmul is data indicating how many times the amplitude value represented by the envelope data B is larger than the minimum value Bmin. The maximum value Bmax is data indicating the maximum value of the envelope data B. The trigger detection flag TrigFlag is a flag indicating whether or not a trigger is detected. More specifically, in the trigger detection flag TrigFlag, the amplitude value represented by the envelope data B exceeds the predetermined value (Bmul × Bmin) larger than the first threshold value represented by the threshold data Th1 (corresponding to Bmin1 and Bmin2 in FIG. 4). Indicates whether or not The attack interpolation speed AtkItpSpeed is a value corresponding to the interpolation coefficient αi set when the envelope extraction unit 24b executes the interpolation process when the amplitude value represented by the envelope data B after the attack is in an increasing state. The release interpolation speed RelItpSpeed is a value corresponding to the interpolation coefficient αd set when the envelope extraction unit 24b executes the interpolation process when the amplitude value represented by the envelope data B after the occurrence of the attack is in a decreasing state. In the present embodiment, the initial value of each data is 0.0001 for the threshold data Th1, 0 for the increase flag IncFlag, 1.0 for the minimum value Bmin, and 0.0 for the maximum value Bmax. Further, 0 is stored in the trigger detection flag TrigFlag, and predetermined values are stored in the nonvolatile memory of the storage unit 24a for the coefficient Bmul, the attack interpolation speed AtkItpSpeed, and the release interpolation speed RelItpSpeed.

  Every time the threshold value determination unit 24c receives envelope data B, the threshold value value is compared with the threshold value data Th1, the minimum value Bmin, the maximum value Bmax, and Bmul × Bmin, and the value of each flag is determined based on the comparison result. . Further, when the threshold detection unit 24c updates the trigger detection flag TrigFlag to 1, the threshold value determination unit 24c notifies the velocity calculation unit 24e of the amplitude value B at that time and instructs the calculation of the velocity Vel. When the velocity calculation unit 24e receives the notification, the velocity calculation unit 24e calculates the velocity Vel by substituting the amplitude value v (where v = B) into a predetermined expression f (v), and the calculation result is used as the sound generation control signal generation unit 24d. To give. The sound generation control signal generation unit 24d monitors the trigger detection flag TrigFlag, and when the value is updated to 1 and the calculation result of the velocity Vel is received from the velocity calculation unit 24e, the sound generation instruction signal to which the calculation result is added Is generated and given to the sound system 3.

The threshold update unit 26 according to the second embodiment includes a motion detection unit 26a instead of the motion detection unit 16a, an operation determination unit 26b instead of the operation determination unit 16b, and a threshold update unit 26c instead of the threshold update unit 16c. In addition to the above-described units, the difference from the threshold update unit 16 is that an interpolation speed update unit 26d is provided. The motion detection unit 26a calculates speed data Vmotion obtained by integrating the speeds in the X, Y, and Z axial directions represented by the output data of the motion detection unit 10 for each axis, and gives the calculation result to the motion determination unit 26b. The motion determination unit 26b refers to the speed data Vmotion given from the motion detection unit 26a, and whether the speed in the vertical direction (Z-axis direction) indicated by the speed data is a negative value (that is, vertically downward). Determine whether or not. If the determination result is Yes, the operation determination unit 26b provides the threshold update unit 26c with a control signal (hereinafter referred to as a threshold update instruction signal) instructing the update of the coefficient Bmul. If the determination result is Yes, the operation determination unit 26b gives a control signal (hereinafter referred to as an interpolation speed update instruction signal) for instructing the update of the attack interpolation speed AtkItpSpeed to the interpolation speed update unit 26d. The threshold update unit 26c updates the set value of the coefficient Bmul stored in the storage unit 24a to a value smaller than the initial value by a predetermined amount, triggered by reception of the threshold update instruction signal. The interpolation speed update unit 26d updates the set value of the attack interpolation speed AtkItpSpeed stored in the storage unit 24a to a value that is smaller by a predetermined amount when receiving the interpolation speed update instruction signal. Note that the update amount of the coefficient Bmul may be appropriately set to a suitable value by performing an experiment. Similarly, the update amount of the attack interpolation speed AtkItpSpeed may be appropriately tested and set to a suitable value (that is, a value that does not cause erroneous determination due to the noise).
The above is the configuration of the sound generation control device 1A.

  Next, trigger detection processing executed by the sound generation control device 1A will be described. In the following, in order to facilitate understanding of the features of the sound generation control device 1A, a case where the conventional sound generation control device 1A is first executed will be described. FIG. 4 is a diagram showing details of the envelope waveform represented by the envelope data B generated by the envelope extraction unit 24b and various data that transitions according to changes in the envelope data B. FIG. 4A is a diagram illustrating a temporal change in the amplitude value represented by the envelope data B generated by the envelope extraction unit 24b. In this figure, “Attack 1” indicates the time when the first strike was applied to the strike surface of the percussion instrument 2 by the striker. “Attack 2” indicates the time at which the second strike was given to the strike surface of the percussion instrument 2 by the striker. FIG. 4B is a diagram showing a time change of the increase flag IncFlag. FIG. 4C is a diagram showing the change over time of the minimum value Bmin. FIG. 4D is a diagram showing the change over time of the maximum value Bmax. FIG. 4E is a diagram showing a change over time of the trigger detection flag TrigFlag. When the sound generation control device 1 is turned on, the threshold determination unit 24c reads initial values of various data from the nonvolatile memory of the storage unit 24a and sets them in a predetermined area of the volatile memory. As a result, as shown in FIGS. 4B to 4E, the initial values are set in the increase flag IncFlag, the minimum value Bmin, the maximum value Bmax, and the trigger detection flag TrigFlag at the time before the occurrence of the attack 1, respectively. Is done.

  The threshold value determination unit 24c performs a trigger detection process every time the envelope data B is received. FIG. 5 is a flowchart showing the contents of a conventional trigger detection process. The threshold determination unit 24c first determines whether or not the amplitude value represented by the envelope data B has increased across the first threshold represented by the threshold data Th1 (step SA10). Specifically, the threshold value determination unit 24c has an amplitude value represented by the received envelope data B that is greater than or equal to the first threshold value represented by the threshold data Th1, and the amplitude value represented by the previously received envelope data B (hereinafter, Bold). ) Is less than the first threshold value. If the determination result in step SA10 is “Yes”, the threshold determination unit 24c updates the increase flag IncFlag to 1, and further updates the minimum value Bmin and the maximum value Bmax to the current amplitude value B (step SA20). ), The process of step SA30 is executed. If the determination result of step SA10 is “No”, the threshold determination unit 24c executes the process of step SA30 without executing the process of step SA20.

  In step SA30, the threshold determination unit 24c determines whether the amplitude value represented by the envelope data B has decreased across the first threshold represented by the threshold data Th1. Specifically, the threshold value determination unit 24c has an amplitude value represented by the received envelope data B that is equal to or smaller than a first threshold value represented by the threshold data Th1, and an amplitude value represented by Bold is greater than the first threshold value. It is determined whether or not. If the determination result in step SA30 is “Yes”, the threshold determination unit 24c updates the increase flag IncFlag to 0, the trigger detection flag TrigFlag to 0, the minimum value Bmin to 1.0, and the maximum value Bmax to 0.0, respectively. (Step SA40), the process of step SA50 is executed. If the determination result of step SA30 is “No”, the threshold determination unit 24c executes the process of step SA50 without executing the process of step SA40.

  In step SA50, the threshold determination unit 24c determines whether or not the amplitude value represented by the envelope data B has changed from increasing to decreasing (whether or not it has reached a maximum). Specifically, the threshold determination unit 24c determines whether or not the amplitude value represented by the envelope data B is less than the maximum value Bmax, and that Bold is equal to the maximum value Bmax. If the determination result of step SA50 is “Yes”, the threshold determination unit 24c updates the minimum value Bmin to the initial value (1.0) (step SA60), and executes the process of step SA70. If the determination result of step SA50 is “No”, the threshold determination unit 24c executes the process of step SA70 without executing the process of step SA60.

  In step SA70, the threshold determination unit 24c determines whether or not the amplitude value represented by the envelope data B has started to increase from a decrease (whether or not it has become a minimum). Specifically, the threshold value determination unit 24c determines whether the amplitude value represented by the envelope data B is greater than the minimum value Bmin and whether Bold is equal to the minimum value Bmin. If the determination result in step SA70 is “Yes”, the threshold determination unit 24c updates the maximum value Bmax to 0.0, the increase flag IncFlag to 1, and the trigger detection flag TrigFlag to 0 (step SA80), and step SA90. Execute the process. If the determination result of step SA70 is “No”, the threshold determination unit 24c executes the process of step SA90 without executing the process of step SA80.

  In step SA90, the threshold determination unit 24c determines whether or not the amplitude value represented by the envelope data B is equal to or greater than the first threshold represented by the threshold data Th1. If the determination result in step SA90 is “No”, the threshold determination unit 24c determines whether or not the value of the increase flag IncFlag is “1” (step SA140). On the other hand, if the determination result in step SA90 is “Yes”, the threshold determination unit 24c determines whether or not the amplitude value represented by the envelope data B is smaller than the minimum value Bmin (step SA100). If the determination result in step SA100 is “Yes”, the threshold determination unit 24c updates the minimum value Bmin to the current amplitude value B (step SA110), and executes the process in step SA120. If the determination result of step SA100 is “No”, the threshold determination unit 24c executes the process of step SA120 without executing the process of step SA110.

  In step SA120, the threshold determination unit 24c determines whether or not the amplitude value represented by the envelope data B is greater than or equal to the maximum value Bmax. If the determination result of step SA120 is “Yes”, the threshold determination unit 24c updates the maximum value Bmax to the current amplitude value B (step SA130), and executes the above-described processing of step SA140. If the determination result of step SA120 is “No”, the threshold determination unit 24c executes the process of step SA140 described above without executing the process of step SA130.

If the determination result in step SA140 is “Yes”, the threshold determination unit 24c determines whether or not the amplitude value represented by the envelope data B is greater than or equal to Bmul × Bmin (step SA150). If the determination result in step SA150 is “No”, the threshold determination unit 24c updates Bold to the amplitude value represented by the envelope data B (step SA170), and ends the trigger detection process. On the other hand, if the determination result in step SA150 is “Yes”, the trigger detection flag TrigFlag is updated to 1 and the increase flag IncFlag is updated to 0 (step SA160), and then the process of step SA170 is executed.
The above is the flow of the trigger detection process.

  In FIG. 4A, only the update of the Bold is performed in the section (section S0) from the occurrence of attack 1 to the time t1. In this section, although the amplitude value represented by the envelope data B sequentially increases with the passage of time, it is less than the first threshold value represented by the threshold data Th1, so the determination result in step SA10 is “No”, and the determination result in step SA30 is also “No”. Therefore, the increase flag IncFlag is not updated, and the increase flag IncFlag remains at the initial value (0) (see FIG. 4B: section S0). Further, in the section S0, the amplitude value represented by the envelope data B does not become the maximum or the minimum, so the determination result in Step SA50 is “No”, and the determination result in Step SA70 is also “No”. Further, since the amplitude value represented by the envelope data B is less than the first threshold value represented by the threshold data Th1, the determination result in step SA90 is also “No”. Also, since the value of the increase flag IncFlag is 0, the determination result in step SA140 is also “No”.

  When the amplitude value represented by the envelope data B reaches the first threshold value represented by the threshold data Th1 at time t1, the determination result in step SA10 is “Yes”, and step SA20 is executed, so the increase flag IncFlag is updated to 1. Then, each value of the minimum value Bmin and the maximum value Bmax is updated to the amplitude value Th1 (= B) at that time (see FIGS. 4B, 4C, and 4D). In the section from time t1 to time t2 (section S1), the amplitude value represented by the envelope data B does not become maximum or minimum, the determination result in step SA50 is “No”, and the determination result in step SA70 is also “No”. Thus, the process of step SA90 is executed without executing the processes of steps SA60 and 80. In the section S1, the amplitude value represented by the envelope data B is equal to or greater than the first threshold value represented by the threshold data Th1, so that the determination result in step SA90 is “Yes”, and the processing in step SA100 is executed. In the section S1, the amplitude value represented by the envelope data B is equal to or greater than Bmin (in this section, Bmin = Th1). Therefore, the determination result in step SA100 is “No”, and the processing in step SA120 is not performed without executing the processing in step SA110. Processing is executed. In the section S1, since the amplitude value represented by the envelope data B is equal to or greater than the maximum value Bmax, the determination result in step SA120 is always “Yes”, and in step SA130 to be executed next, Bmax is the amplitude represented by the envelope data B at that time. The value is updated, and the process of step SA140 is executed. In the section S1, since the value of the increase flag IncFlag is 1, the determination result in step SA140 is “Yes”, and the process in step SA150 is executed. Since the amplitude value represented by the envelope data B is less than Bmul × Bmin (Bmin = Th1), the determination result at step SA150 is “No”, and the process at step SA170 is executed without executing the process at step SA160. Then, the update process of the Bold is performed. That is, in the section S1, the increase flag IncFlag is maintained at 1, the minimum value Bmin is maintained at Th1, the trigger detection flag TrigFlag is maintained at 0, and only the maximum values Bmax and Bold are updated (FIGS. 4B and 4C). ), (E), (d): see section S1).

  After time t1, the amplitude value represented by the envelope data B does not increase across the first threshold value represented by the threshold data Th1, and hence the determination result in step SA10 is always “No”. Since the amplitude value represented by the envelope data B does not decrease across the first threshold value represented by the threshold data Th1 until the time t7, the determination result in step SA30 is always “No” until the time t7. It becomes. Further, since the amplitude value represented by the envelope data B is always equal to or greater than the first threshold value represented by the threshold data Th1 until the time t7, the determination result in step SA90 is always “Yes”. Also, except for the times t3 and t6, the amplitude value represented by the envelope data B does not become maximal, so the determination result in step SA50 is always “No”. Since the amplitude value represented by the envelope data B does not become minimum except for the time t4, the determination result in step SA70 is always “No”.

  At time t2, since the amplitude value represented by the envelope data B is equal to or greater than the minimum value Bmin, the determination result of step SA100 is “No”, and the process of step SA120 is executed without executing the process of step SA110. . At time t2, since the amplitude value represented by the envelope data B is equal to or greater than the maximum value Bmax, the determination result in step SA120 is “Yes”, and Bmax is updated in step SA130 to be executed next, and step SA140 is executed. Each of the above processes is executed until time t3. At time t2, since the value of the increase flag IncFlag is 1, the determination result in step SA140 is “Yes”, and the process in step SA150 is executed. At time t2, since the amplitude value represented by the envelope data B reaches Bmul × Bmin (where Bmin = Th1), the determination result in step SA150 is “Yes”, and the processing in step SA160 is executed. That is, the trigger detection flag TrigFlag is updated to 1 and the increase flag IncFlag is updated to 0 (see FIGS. 4E and 4B). As a result, the internal state of the sound generation control device 1A transitions from the silent state to the sound generation state. At this time, the threshold determination unit 24c notifies the velocity calculation unit 24e of the amplitude value represented by the envelope data B at time t2. The velocity calculation unit 24e substitutes the notified value into a predetermined formula f (v) (where v = B), and calculates the velocity Vel, and gives the calculation result to the sound generation control signal generation unit 24d. The sound generation control signal generation unit 24d adds the calculation result to the sound generation instruction signal and outputs it to the sound system 3. When the process of step SA160 is executed, the process of step SA170 is then executed, and the Bold is updated.

  Since the increase flag IncFlag is updated to 0, in the section (section S2) from time t2 to time t3, the determination result of step SA140 is “No”, and the processing of steps SA150 and 160 is not performed, and step SA170 is performed. The process is executed. That is, in the section S2, the increase flag IncFlag is maintained at 0, the minimum value Bmin is maintained at the amplitude value (Th1) represented by the envelope data B at time t1, the trigger detection flag TrigFlag is maintained at 1, and the maximum values Bmax and Bold are updated. Only is performed (see FIGS. 4B, 4C, 4E, and 4D: section S2).

  At time t3, the amplitude value represented by envelope data B changes from increasing to decreasing. That is, since the amplitude value represented by the envelope data B is maximum, the determination result in step SA50 is “Yes”, and the value of the minimum value Bmin is updated to 1.0 in the process of step SA60 to be executed next (FIG. 4 (c)). In the section from time t3 to time t4 (section S3), the amplitude value represented by the envelope data B is less than the minimum value Bmin. Therefore, the determination result in step SA100 is “Yes”, and the minimum value Bmin is the current value. The amplitude value represented by the envelope data B is updated, and the process of step SA120 is executed. In the section S3, since the amplitude value represented by the envelope data B is less than the maximum value Bmax, the determination result of step SA120 is “No”, and the process of step SA140 is executed without executing the process of step SA130. In the section S3, since the value of the increase flag IncFlag is 0, the determination result of step SA140 is “No”, and the process of step SA170 is executed without executing the process of step SA150. That is, in the section S3, the increase flag IncFlag is maintained at 0, the maximum value Bmax is maintained at the amplitude value (1) represented by the envelope data B at time t3, the trigger detection flag TrigFlag is maintained at 1, and the minimum values Bmin and Bold are updated. Only (see FIGS. 4B, 4D, 4E, and 4C: section S3).

  At time t4, a second attack (attack 2) occurs, and the amplitude value represented by the envelope data B changes from decreasing to increasing. That is, at time t4, since the amplitude value represented by the envelope data B is minimal, the determination result of step SA70 is “Yes”, and the process of step SA80 is executed. That is, the maximum value Bmax is updated to 0.0, the increase flag IncFlag is updated to 1, and the trigger detection flag TrigFlag is updated to 0 (see FIGS. 4D, 4B, and 4E), and the internal state of the sound generation control device 1A is updated. Transitions from a sounding state to a silent state.

  At time t4, since the amplitude value represented by the envelope data B is equal to or greater than the minimum value Bmin, the determination result of step 100 is “No”, and the process of step SA120 is executed without executing the process of step 110. At time t4, since the amplitude value represented by the envelope data B is equal to or greater than the maximum value Bmax, the determination result in step SA120 is “Yes”. Next, in step 130, the maximum value Bmax is changed to the amplitude value B at that time. It is updated and the process of step SA140 is executed. Since the value of the increase flag IncFlag is updated to 1, the determination result in step SA140 is “Yes” at time t4, and the process in step SA150 is executed. At time t4, since the amplitude value represented by the envelope data B is less than Bmul × Bmin (where Bmin = Bmin2), the determination result at step SA150 is “No”, and the process at step SA160 is not executed. The above process is executed, and the Bold is updated.

  In a section from time t4 to time 5 (section S4), processing similar to the processing from step SA100 to step SA170 at time t4 is executed. That is, in the section S4, the increase flag IncFlag is maintained at 1, the trigger detection flag TrigFlag is maintained at 0, the minimum value Bmin is maintained at the amplitude value (Bmin2) represented by the envelope data B at time t4, and the maximum values Bmax and Bold are updated. Only (see FIGS. 4B, 4E, 4C, and 4D: section S4).

  At time t5, processing similar to the processing from step SA100 to step SA150 in the section S4 is executed. At time t5, since the amplitude value represented by the envelope data B reaches Bmul × Bmin (where Bmin = Bmin2), the determination result in step SA150 is “Yes”, and the process in step SA160 is executed. That is, the trigger detection flag TrigFlag is updated to 1 and the increase flag IncFlag is updated to 0 (see FIGS. 4E and 4B). As a result, the internal state of the sound generation control device 1A transitions from the silent state to the sound generation state. Thereafter, similar to the processing performed at time t2, the threshold value determination unit 24c notifies the velocity calculation unit 24e of the amplitude value represented by the envelope data B at time t5, the velocity calculation processing by the velocity calculation unit 24e, and the sound generation control signal generation. The sound generation instruction signal is output to the sound system 3 by the unit 24d.

  In a section from time t5 to time t6 (section S5), processing similar to that in section S2 is performed. Therefore, in the section S5, the increase flag IncFlag is maintained at 0, the minimum value Bmin is maintained at the amplitude value (Bmin2) represented by the envelope data B at the time t4, the trigger detection flag TrigFlag is maintained at 1, and the maximum values Bmax and Bold are maintained. Only updating is performed (see FIGS. 4B, 4C, 4E, and 4D: section S5).

  At time t6, the amplitude value represented by envelope data B changes from increasing to decreasing. That is, since the amplitude value represented by the envelope data B is maximum, the determination result in step SA50 is “Yes”, and the value of the minimum value Bmin is updated to 1.0 in the process of step SA60 to be executed next (FIG. 4 (c)). In the section from time t6 to time t7 (section S6), the amplitude value represented by the envelope data B is less than the minimum value Bmin. Therefore, the determination result in step SA100 is “Yes”, and the minimum value Bmin is the current value. The amplitude value represented by the envelope data B is updated, and the process of step SA120 is executed. In the section S6, since the amplitude value represented by the envelope data B is less than the maximum value Bmax, the determination result in step SA120 is “No”, and the process in step SA140 is executed without executing the process in step SA130. In section S6, since the value of the increase flag IncFlag is 0, the determination result in step SA140 is “No”, and the process in step SA170 is executed without executing the process in step SA150. That is, in the section S6, the increase flag IncFlag is maintained at 0, the maximum value Bmax is maintained at the amplitude value (1) represented by the envelope data B at time t6, the trigger detection flag TrigFlag is maintained at 1, and the minimum values Bmin and Bold are updated. Only (see FIGS. 4B, 4D, 4E, and 4C: section S6).

  When the amplitude value represented by the envelope data B reaches the first threshold value represented by the threshold data Th1 at time t7, the determination result in step SA30 is “Yes”, step SA40 is executed, the increase flag IncFlag is set to 0, and the trigger is detected. The flag TrigFlag is updated to 0, the minimum value Bmin is updated to 1.0, and the maximum value Bmax is updated to 0.0 (see FIGS. 4B, 4E, 4C, and 4D). At time t7, since the amplitude value represented by the envelope data B does not become maximum or minimum, the determination result of step SA50 is “No”, the determination result of step SA70 is also “No”, and the process of step SA90 is executed. Is done. Since the amplitude value represented by the envelope data B is equal to or less than the first threshold value represented by the threshold data Th1, the determination result in step SA90 is also “No”, and the process in step SA140 is executed. At time t7, since the value of the increase flag IncFlag is 0, the determination result in step SA140 is “No”, so that the process in step SA170 is executed and only the Bold is updated without executing the process in step SA150. .

  In the trigger detection process, noise may be superimposed on the envelope waveform represented by the envelope data B given by the envelope extraction unit 24b to the threshold determination unit 24c. FIG. 6 is a diagram illustrating a state in which noise is superimposed on the envelope waveform represented by the envelope data B generated by the envelope extraction unit 24b. In this figure, “Δt” is the time corresponding to the section S4 in FIG. 4, and Δt = t5−t4. In the example shown in FIG. 6, noise is superimposed on a region corresponding to the section S4 of the envelope waveform. In the conventional trigger detection process, an erroneous determination caused by noise in the process of step SA150 (see FIG. 5) executed by the threshold determination unit 24c, that is, whether or not the amplitude value represented by the envelope data B is greater than or equal to Bmul × Bmin. Is set to a large value for the coefficient Bmul. However, when a large value is set for the coefficient Bmul, the time Δt required until the determination result in step SA150 becomes “Yes” after the amplitude value represented by the envelope data B starts from decreasing to increasing increases. The same applies to the time required for the determination result in step SA150 to be “Yes” after the amplitude value represented by the envelope data B increases across the threshold data Th1. As described above, if a large value is set for the coefficient Bmul in order to avoid erroneous determination due to noise, a note-on signal with velocity cannot be output quickly, and a note-on signal is applied to a MIDI sound source or the like. Latency occurs.

  The sound generation control device 1A according to the present embodiment prevents the occurrence of the latency by executing a process that clearly shows the characteristics of the present invention. Hereinafter, the details of the processing that remarkably shows the features of the present invention will be described with reference to FIGS. FIG. 7 is a flowchart showing the contents of the threshold update process executed by the threshold update unit 26c. FIG. 8 is a flowchart showing the contents of the interpolation speed update process executed by the interpolation speed update unit 26d. FIG. 9 is a diagram showing details of the envelope waveform represented by the envelope data B generated by the envelope extraction unit 24b and various data that transition in accordance with the change of the envelope data B. FIG. 9A is a diagram showing an envelope waveform represented by envelope data B generated by the envelope extraction unit 24b. FIG. 9B is a diagram showing a time change of the speed data Vmotion output from the motion detection unit 26a. FIG. 9C is a diagram showing a change with time of the coefficient Bmul. FIG. 9D is a diagram showing a change over time in the attack interpolation speed AtkItpSpeed. The threshold update unit 26c and the interpolation speed update unit 26d according to the present embodiment execute step SB10 shown in FIG. 7 and step SC10 shown in FIG.

  More specifically, as shown in FIG. 9B, the velocity data output by the motion detection unit 26a when at least one percussion body is moving toward the percussion instrument 2 immediately before the attack 2 is generated. Vmotion changes in the negative direction. Whenever the speed data Vmotion is received from the motion detection unit 26a, the motion determination unit 26b determines whether or not the speed data Vmotion has changed in the negative direction. If the determination result is Yes, the threshold update unit 26c Is given a threshold update instruction signal. When the threshold update unit 26c receives the threshold update instruction signal, the threshold update unit 26c updates the coefficient Bmul to a smaller value as shown in FIG. 9C (FIG. 7: step SB10), and the value is stored in the storage unit 24a. Store in memory. For this reason, in the series of processing shown in FIG. 5 executed by the threshold determination unit 24c, the value represented by Bmul × Bmin is smaller than that before the coefficient Bmul is updated, and the amplitude value represented by the envelope data B has started to increase from the decrease. Thereafter, the time required until the determination result of step SA150 becomes “Yes” is shortened to Δt ′ (Δt ′ <Δt). This also applies to the time required for the determination result in step SA150 to be “Yes” after the amplitude value represented by the envelope data B increases across the threshold data Th1. Therefore, after the amplitude value represented by the envelope data B exceeds the first threshold value, the sound generation control signal generation unit 24d can quickly output the sound generation instruction signal to which the velocity is added. Thus, it is possible to prevent the latency that occurs when applying to the. If the threshold value update unit 26c determines that the speed data Vmotion received from the motion detection unit 26a has subsequently changed in the positive direction, the threshold value update unit 26c updates the coefficient Bmul to a larger value.

  If the coefficient Bmul is updated to a smaller value, an erroneous determination due to noise may occur in step SA150. Therefore, when the determination result of whether or not the speed data Vmotion received from the motion detection unit 26a has changed in the negative direction is Yes, the motion determination unit 26b sends an interpolation speed update instruction signal to the interpolation speed update unit 26d. give. When the interpolation speed update unit 26d receives the interpolation speed update instruction signal, the attack interpolation speed is updated by updating the attack interpolation speed AtkItpSpeed to a smaller value as shown in FIG. 9D (FIG. 8: step SC10). The time is delayed (the sampling time interval is increased), and the value is stored in the volatile memory of the storage unit 24a. Based on the updated attack interpolation speed AtkItpSpeed, the envelope extraction unit 24b performs an interpolation process on the output data of the vibration detection unit 12, and generates envelope data representing an envelope of a waveform represented by the output data after the interpolation process. This is given to the threshold determination unit 24c. As a result, the probability that the envelope data B given to the threshold value determination unit 24c includes noise is reduced, and the occurrence of the erroneous determination can be prevented even if the set value of the coefficient Bmul is updated to a smaller value. In addition, since the threshold value determination unit 24c executes step SA150 shown in FIG. 5 based on the envelope data B, it is possible to improve the accuracy of the value of the velocity Vel. If the interpolation speed update unit 26d determines that the velocity data Vmotion received from the motion detection unit 26a has subsequently changed in the positive direction, the interpolation velocity update unit 26d updates the attack interpolation speed AtkItpSpeed to a larger value.

  Thus, according to the present embodiment, it is possible to avoid the occurrence of latency in the sound generation control of the percussion instrument performance sound by the electronic sound source. In this embodiment, the application example to the sound generation control in the mute performance of the live drum has been described. However, the sound generation control device 1A is incorporated in an electronic percussion instrument such as an electronic drum, and the sound generation control device 1A is used for sound generation control in the electronic percussion instrument. Of course, it may be applied.

Although the first and second embodiments of the present invention have been described above, the following modifications may of course be added to this embodiment.
(1) In the above embodiment, as a performance mode of the percussion instrument 2, a mode in which the hitting surface is hit with a single stick, that is, a mode in which only one hitting body is used has been described. Also good. For example, the performer may hold one stick in each of his left and right hands and hit the percussion surface of the percussion instrument 2 using these two sticks. In such a mode, one of the two sticks moves toward the striking surface and the other moves away from the striking surface in the continuous striking phase. Therefore, in such a mode, when it is determined that one striking body is moving toward the striking surface and the other striking body is moving in a direction away from the striking surface in the sounding state, What is necessary is just to make the threshold value update means 16 perform the process which updates the threshold value of 2 to a larger value.

(2) In the above embodiment, the update amount Δ of the second threshold th2 by the threshold update unit 16 is a fixed value. However, according to the peak value of the envelope of the waveform of vibration generated on the hitting surface due to the most recent hit The update amount Δ may be determined. Specifically, the update amount Δ is increased as the peak value increases. The stronger the most recent impact, the larger the peak value and the smaller the vibration attenuation with time. For this reason, if the renewal amount Δ is set to a constant value regardless of the strength of the latest hit, the latest hit is strong, and the vibration of the hitting surface is not sufficiently attenuated until the next hit (that is, If the value does not fall below the second threshold th2), sound omission occurs. According to this aspect, occurrence of such sound omission can be prevented.

(3) In the above embodiment, when the vertical velocity indicated by the output data of the motion detector 14 is a positive value, it is determined that the impacting body is moving toward the hitting surface. However, it stores the output signal output from the motion detection means 10 or the feature quantity indicating the feature of the output signal under the situation where the impacting body is moving toward the hitting surface, and the motion determination unit according to the stored contents You may make it make 16b perform the said determination. For example, if the output signal output from the motion detection means 10 is stored, the cross-correlation value between the waveform represented by the recorded signal and the waveform represented by the output data of the motion detection unit 14 is calculated, and the cross-correlation value is calculated. Is equal to or greater than a predetermined value, it is determined that the hitting body is moving toward the hitting surface. According to such an aspect, by recording a performance action peculiar to the performer prior to the performance of the percussion instrument, sound omission caused by repeated strikes can be surely prevented while taking into account the individual performance characteristics of the performer. It becomes possible to do.

(4) In the above embodiment, the operation of detecting the movement of one or a plurality of percussion bodies (one stick in the above embodiment) for hitting the striking surface of the percussion instrument 2, and outputting a signal indicating the detection result Although the acceleration sensor built in the stick is used as the detection means, an acceleration sensor attached to the player's wrist using a wristband or the like may be used as the motion detection means. Further, a video camera that captures the state of the performer who plays the percussion instrument 1 may be used as the motion detection means. This is because the player's action can be determined by performing image analysis on the output signal of the video camera (a video signal representing the performance of the percussion instrument 1).

(5) Although the interpolation speed update unit 26d is provided in the sound generation control device 1A in the above embodiment, the interpolation speed update unit 26d may be omitted. According to this aspect, if the noise superimposed on the envelope waveform is small, the same effect as in the above embodiment can be obtained. Further, according to this aspect, it is possible to reduce the processing load and power consumption of the sound generation control device 1A.

(6) In the above embodiment, the sound generation control signal generation unit 24 adds the velocity Vel calculated by the velocity calculation unit 24e to the note-on signal based on the amplitude value represented by the envelope data B at the time of the process of step SA160 in FIG. However, a value obtained by weighting and adding the velocity Vel and the value of the velocity data Vmotion in the vicinity of the above time using a coefficient r (0 ≦ r ≦ 1), that is, Vmotion × r + Vel × (1-r) is a note-on signal. May be added.

(7) In the above embodiment, the acceleration sensor 10a is attached to the hitting body, and the movement of the hitting body when hitting the hitting surface of the percussion instrument 2 is detected. However, the acceleration sensor 10a is attached to the bass drum or hi-hat pedal. The movement of the pedal when striking the drum or cymbal striking surface may be detected. Also in this case, the same effect as the first and second embodiments can be obtained.

  DESCRIPTION OF SYMBOLS 1,1A ... Sound generation control apparatus, 10 ... Motion detection means, 12 ... Vibration detection means, 14, 24 ... Sound generation control means, 14a, 24a ... Memory | storage part, 14b, 24b ... Envelope extraction part, 241 ... Full wave rectification part, 242: Interpolation unit, 2421, 2422 ... Amplification unit, 2423, 2424 ... Addition unit, 2425 ... Delay processing unit, 14c, 24c ... Threshold determination unit, 14d, 24d ... Sound generation control signal generation unit, 16, 26 ... Threshold update means , 16a, 26a ... motion detection unit, 16b, 26b ... motion determination unit, 16c, 26c ... threshold update unit, 26d ... interpolation speed update unit, 2 ... percussion instrument, 3 ... sound system.

Claims (5)

Motion detecting means for detecting the movement of one or a plurality of hitting bodies for hitting the percussion surface of the percussion instrument, and outputting a signal indicating the detection result;
Vibration detecting means for detecting vibration generated on the hitting surface in response to hitting by the one or more hitting bodies, and outputting a signal representing a waveform of the vibration;
When the amplitude of the envelope of the output signal of the vibration detecting means exceeds the first threshold, the sound transitions to the sounding state and the sound source is instructed to sound, and the amplitude falls below the second threshold. Sound generation control means for instructing the electronic sound source to stop sound generation while transitioning to a silent state as
Threshold update that analyzes the output signal of the motion detection means and updates the second threshold value to a larger value when it is determined that at least one impacting body is moving toward the hitting surface in the sounding state Means,
A sound generation control device. Velocity calculating means for calculating the velocity based on the amplitude when the amplitude of the envelope exceeds the first threshold,
The sound generation control means adds the velocity calculated by the velocity calculation means to the sound generation instruction,
The threshold value updating means updates the first threshold value to a smaller value when it is determined that the at least one impacting body is moving toward the percussion surface of the percussion instrument. 2. The sound generation control device according to 1. Motion detecting means for detecting the movement of one or a plurality of hitting bodies for hitting the percussion surface of the percussion instrument, and outputting a signal indicating the detection result;
Vibration detecting means for detecting vibration generated on the hitting surface in response to hitting by the one or more hitting bodies, and outputting a signal representing a waveform of the vibration;
Velocity calculating means for calculating the velocity based on the amplitude when the amplitude of the envelope of the output signal of the vibration detecting means exceeds a first threshold;
Sound generation control means for giving an electronic sound source the sound velocity by adding the velocity calculated by the velocity calculation means to the sound generation instruction when the amplitude of the envelope exceeds the first threshold value,
Analyzing the output signal of the motion detection means, and when it is determined that at least one hitting body is moving toward the hitting surface, the threshold update means for updating the first threshold value to a smaller value;
A pronunciation control apparatus characterized by comprising: An envelope extracting means for performing an interpolation process on the output signal of the vibration detecting means and outputting envelope data representing the envelope;
The output signal of the motion detection means is analyzed, and when it is determined that the at least one impacting body is moving toward the percussion surface of the percussion instrument, the interpolation speed in the envelope extraction means is updated to a smaller value. The sound generation control device according to claim 1, further comprising an interpolation speed update unit. A recording means for recording an output signal output from the motion detection means while the impacting body is moving toward the hitting surface or a feature value indicating a feature of the output signal;
5. The sound generation control device according to claim 1, wherein the threshold value updating unit performs the determination with reference to a recording content of the recording unit.

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