JP2018036640A - Electronic percussion instrument - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic percussion instrument, which can resolve a so-called hotspot by approximately uniformizing distribution of beat sensitivity on a percussion surface, without delaying a sound production instruction for a beat sound.SOLUTION: In an electronic drum 1, when a central sensor 10 detects a beat before peripheral sensors (a first peripheral sensor 20 to a third peripheral sensor 40) detect it, a velocity is calculated by weighting operation between the peak of the beat detected by the central sensor 10 and the peak of the beat detected by the peripheral sensors after completion of a scanning time by the central sensor 10. On the other hand, when the beat is detected by the peripheral sensors earlier, and the central sensor 10 does not detect the beat within the scanning time by the peripheral sensors, a velocity is calculated from the peak of the beat detected by the peripheral sensors. Since a generation instruction for a musical sound is made based on these velocities, a so-called hotspot can be resolved by approximately uniformizing distribution of beat sensitivity on a percussion surface, without delaying a generation instruction for the musical sound.SELECTED DRAWING: Figure 9

Description

  The present invention relates to an electronic percussion instrument, and more particularly to an electronic percussion instrument that can eliminate a so-called hot spot by making the distribution of hitting sensitivity of a hitting surface substantially uniform, and that does not delay the instruction to generate a hitting sound.

  Various electronic percussion instruments such as an electronic drum have been developed. In the electronic percussion instruments of Patent Documents 1 and 2, only one hit sensor for detecting hit is provided at the center of the hitting surface. However, the impact sensitivity of the impact sensor is higher as it is closer to the sensor, and lower as it is farther from the sensor. Therefore, in an electronic percussion instrument having only one batting sensor in the center of the hitting surface, a so-called hot spot region in which the hitting sound becomes abnormally large is generated in the center of the hitting surface where the hitting sensor is located. On the other hand, since the hitting sensitivity is remarkably reduced at the periphery of the hitting surface away from the central hitting sensor, it is not possible to detect a weak hit at the peripheral part when the hitting face diameter is increased.

  On the other hand, in the electronic percussion instruments disclosed in Patent Documents 3 to 7, a plurality of hitting sensors are arranged on the hitting surface, and the hitting strength is calculated based on the detection result of each hitting sensor, whereby the hitting sensitivity distribution of the hitting surface is calculated. So as to eliminate so-called hot spots. Similarly, in the electronic percussion instruments disclosed in Patent Documents 8 to 11, a central sensor is disposed at the center of the striking surface, and peripheral sensors are disposed at the periphery of the striking surface, so that the impact sensitivity distribution on the striking surface is substantially uniform.

Japanese Patent Laid-Open No. 10-020854 JP-A-10-111690 Japanese Patent Laid-Open No. 62-501653 Japanese Patent Laid-Open No. 05-232943 JP 2005-037922 A JP2011-158594A JP 2014-119664 A Japanese Utility Model Publication No. 54-172726 JP 2012-203191 A JP 2009-186886 A Special table 2014-524008 gazette

  However, according to the electronic percussion instrument having a plurality of hitting sensors, it is possible to eliminate so-called hot spots by making the hitting sensitivity distribution substantially uniform. Since it takes a long time to detect the sound, there is a problem that the instruction to pronounce the hit sound is delayed.

  The present invention has been made in order to solve the above-described problems. An electronic device that can eliminate a so-called hot spot by making the distribution of the hitting sensitivity of the hitting surface substantially uniform, and that does not delay the instruction to pronounce the hitting sound. The purpose is to provide percussion instruments.

  In order to achieve this object, an electronic percussion instrument according to claim 1 comprises a striking surface and a striking sensor for detecting striking on the striking surface, and the striking sensor is disposed at the center of the striking surface. A central sensor and a peripheral sensor disposed in a peripheral portion of the hitting surface, and when the central sensor detects a hit prior to the peripheral sensor, A first weight means for executing a weight process for a predetermined time; and a second weight for executing a weight process for a second predetermined time from the detection of a hit by the peripheral sensor when the peripheral sensor detects a hit before the central sensor. When the weighting means and the first weighting means are in operation, after the end of the weighting process by the first weighting means, the impact strength is calculated based on the detection results of the central sensor and the peripheral sensor, In the operation of the two-weight means, if the central sensor does not detect the impact within the period of the weight processing by the second weight means, the strength calculating means for calculating the impact strength based on the detection result of the peripheral sensor, and Sound generation instruction means for instructing sound generation of the hitting sound based on the hitting intensity calculated by the intensity calculating means. The striking strength by the striking strength calculating means is calculated by, for example, the striking speed (velocity).

  According to a second aspect of the present invention, in the electronic musical instrument according to the first aspect, when the central sensor detects an impact within the period of the weight processing by the second weight means during the operation of the second weight means, Third weight means for executing weight processing for a third predetermined time from hit detection is provided, and the strength calculating means is based on detection results of the central sensor and the peripheral sensor after completion of the weight processing by the third weight means. To calculate the impact strength.

  According to a third aspect of the present invention, in the electronic musical instrument according to the second aspect, the first predetermined time and the third predetermined time are the same time.

  According to a fourth aspect of the present invention, in the electronic musical instrument according to any one of the first to third aspects, when the hitting surface is viewed in plan, the hitting surface is formed in a circular shape, and the center sensor is arranged at the center of the hitting surface. In addition, at least three of the peripheral sensors are arranged at equal intervals on a circumference centered on the central sensor.

  According to the electronic percussion instrument of the first aspect, the percussion sensor has a center sensor disposed at the center of the striking surface and a peripheral sensor disposed at the periphery of the striking surface. . When the central sensor detects a hit prior to the peripheral sensor, the first weight means executes a weight process for a first predetermined time from the hit detection of the central sensor. After the end of the weight process, the strength calculation means calculates the impact strength based on the detection results of the central sensor and the peripheral sensor, and the sound generation instruction means instructs the pronunciation of the hit sound based on the calculated impact strength. .

  Thus, the impact strength is calculated based on the detection results of the central sensor disposed at the center of the striking surface and the peripheral sensor disposed at the periphery of the striking surface. So that the so-called hot spot can be eliminated. Even if the time difference between hitting detection by the central sensor and the peripheral sensor becomes large as a result of the large hitting surface being formed, the calculation of the hitting strength is performed when the central sensor detects hitting before the peripheral sensor. Since it is performed after the elapse of the first predetermined time from the hit detection of the central sensor, the instruction for sound generation of the hitting sound is not delayed.

  On the other hand, when the peripheral sensor detects a hit prior to the central sensor, the second weight means executes a weight process for a second predetermined time from the hit detection of the peripheral sensor. If the central sensor does not detect a hit within the weight processing period, the strength calculating means calculates the hit strength based on the detection results of the peripheral sensors, and the sound generation instruction means hits based on the calculated hit strength. Sound generation is instructed.

  Therefore, even when a weak hit that cannot be detected by the central sensor is made at the periphery of the hitting surface, the peripheral sensor can detect the weak hit and control the sound generation. In addition, if the center sensor does not detect the hit within the second predetermined time after the peripheral sensor detects the hit, the sound generation instruction is issued without waiting for the hit detection by the center sensor. Therefore, even in such a case, the instruction for sound generation of the hitting sound is not delayed.

  According to the electronic percussion instrument of claim 2, in addition to the effect of claim 1, the following effect is provided. When the peripheral sensor detects a hit prior to the central sensor, the second weight means executes the weight processing for the second predetermined time from the detection of the peripheral sensor hit, and the central sensor detects the hit within the weight processing period. Then, the weight process for the third predetermined time is executed by the third weight means from the hit detection of the center sensor. After the end of the weight processing by the third weight means, the strength calculating means calculates the striking strength based on the detection results of the central sensor and the peripheral sensor, and based on the calculated striking strength, the sound generation instruction means generates the hit sound. Instructions are given.

  Now, since the amount of deformation (deflection) of the striking surface is larger in the center of the striking surface than in the periphery of the striking surface, the central sensor disposed in the central portion of the striking surface is the periphery disposed in the perimeter of the striking surface. Compared to sensors, the output range for impact is wide, and impact detection sensitivity is good. Therefore, even when the peripheral sensor detects a hit prior to the central sensor, if the central sensor detects a hit within the second predetermined time, the central sensor can secure the hit detection time for the third predetermined time, The striking strength is calculated based on the detection results of the sensor and the peripheral sensor. Therefore, even when the peripheral sensor detects a hit before the center sensor, the hit strength can be calculated using the detection result of the center sensor with good sensitivity.

  In this case, the sound generation instruction for the hit sound is delayed by the time from the hit detection of the peripheral sensor to the hit detection of the central sensor. However, since the determination period of whether or not there is a hit detection of the central sensor is within the second predetermined time from the hit detection of the peripheral sensors, the delay time of the sound generation instruction is stopped within a predetermined time (second predetermined time). be able to. That is, by adjusting the second predetermined time, the delay time of the sound generation instruction can be stopped within the range of the design value.

  According to the electronic percussion instrument of claim 3, in addition to the effect of claim 2, the following effect is provided. Since the first predetermined time and the third predetermined time are the same time, if the central sensor detects an impact, the central sensor may detect whether the impact is detected before or after the peripheral sensor. It is possible to calculate the striking strength using the detection result of the central sensor with good sensitivity.

  According to the electronic percussion instrument of the fourth aspect, in addition to the effect of any one of the first to third aspects, the following effect is achieved. When the striking surface is viewed in plan, the striking surface is formed in a circular shape, the central sensor is disposed at the center of the striking surface, and the peripheral sensors are equally spaced on the circumference centered on the central sensor. Are arranged at least three. Therefore, it is possible to appropriately detect the hit and calculate the hit strength of the entire hitting surface formed in a circle.

It is a disassembled perspective view of the electronic drum in one Embodiment of this invention. It is sectional drawing of an electronic drum. It is a top view showing each sensor arrangement of an electronic drum typically. It is a block diagram which shows the electric constitution of an electronic drum. (A) is a figure showing a central sensor hitting position table typically, (b) is a figure showing a peripheral sensor hitting position table typically, (c) is a sensor value ring buffer. It is the figure represented typically. (A) is a voltage-time graph of a voltage waveform (output waveform from the central sensor) based on an impact at the central sensor, and (b) is detected for a certain impact on the impact surface of the electronic drum. FIG. 5 is a voltage-time graph of voltage waveforms in the first peripheral sensor, the second peripheral sensor, and the third peripheral sensor. (A) is a flowchart of the initialization process, and (b) is a flowchart of the MIDI reception process. It is a flowchart of a regular process. It is a flowchart of a center sensor hit process. It is a flowchart of a periphery sensor impact process.

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

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

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

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

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

  The rim 4 is an annular member that applies tension to the head 3. The rim 4 includes a cylindrical frame contact portion 4a whose lower end (end portion on the fixed portion 5 side, lower end portion in FIG. 2) contacts the frame portion 3b, and an upper end (frame portion) of the frame contact portion 4a. An annular elastic member 4b disposed along the entire circumference at the end opposite to the end in contact with 3b), and an annular flange projecting radially outward from the lower end of the frame contact portion 4a. Part 4c.

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

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

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

  The frame 6 is a bowl-shaped member for supporting various members such as the central sensor 10 and the first peripheral sensor 20 to the third peripheral sensor 40 on the inner peripheral side of the shell 2, and is formed of a synthetic resin. The frame 6 includes a bottom portion 6a arranged to face the head 3 with a predetermined distance, a side wall portion 6b erected from an outer edge of the bottom portion 6a, and a plurality of centers erected from the bottom portion 6a to the head 3 side. The protrusion 6c, a connecting part 6d for connecting the plurality of central protruding parts 6c, a plurality of ribs 6e extending radially from the central protruding part 6c and the connecting part 6d to the side wall part 6b, and the rib 6e And a peripheral protrusion 6f formed integrally.

  A curved portion 6b1 that protrudes outward in the radial direction and curves downward is formed at the upper end of the side wall portion 6b. The curved portion 6 b 1 is engaged along the edge of the upper end of the shell 2, so that the frame 6 is supported on the edge of the opening on the upper end side of the shell 2.

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

  The plurality of ribs 6e are respectively formed so as to stand up from the bottom 6a in a flat plate shape, and are arranged at equal intervals along the circumferential direction of the shell 2. Of the plurality of ribs 6e, three ribs 6e are provided. A pair of peripheral projections 6f is formed in each of the two.

  The peripheral projections 6f are formed as a pair along the extending direction of the rib 6e, and female screw holes are formed at the upper ends of the pair of peripheral projections 6f. The pair of peripheral protrusions 6f are disposed at three locations along the circumferential direction of the shell 2, and the first peripheral sensor 20 to the third peripheral sensor 40 are disposed at the three peripheral protrusions 6f, respectively. . Therefore, the first peripheral sensor 20 to the third peripheral sensor 40 are arranged at equal intervals along the circumferential direction of the shell 2.

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

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

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

  The first peripheral sensor 20, the second peripheral sensor 30, and the third peripheral sensor 40 are sensors that detect that the hitting surface has been hit, and are equally spaced on the circumference with the central sensor 10 as the center in plan view. It is arranged.

  In addition, the 1st surrounding sensor 20, the 2nd surrounding sensor 30, and the 3rd surrounding sensor 40 are comprised as the same sensor except the position arrange | positioned. Therefore, the second peripheral sensor 30 and the third peripheral sensor 40 are denoted by the same reference numerals as those of the first peripheral sensor 20, and detailed description thereof is omitted.

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

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

  The head sensor 23 is a disk-shaped sensor that detects that the hitting surface has been hit, and is composed of a piezoelectric element. The head sensor 23 is disposed at a position closer to the hitting surface than the head sensor 13 of the central sensor 10 (that is, the head sensor 23 and the film member 3a are more spaced apart from each other than the facing distance between the head sensor 13 and the film member 3a). The facing distance is shorter).

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

  That is, the first peripheral sensor 20 to the third peripheral sensor 40 are sensors having substantially the same structure as the central sensor 10 (the cushion members 14 and 24 are in contact with the membrane member 3a, and the lower surfaces of the cushion members 14 and 24 are The head sensors 13 and 23 are provided as sensors). Thereby, compared with the case where the center sensor 10 and the 1st periphery sensor 20-the 3rd periphery sensor 40 are comprised from a sensor of another structure, the manufacturing cost of the electronic drum 1 can be reduced. Further, since it is not necessary to match the hit output characteristics of the central sensor 10 with the hit output characteristics of the first peripheral sensor 20 to the third peripheral sensor 40, the design can be facilitated accordingly.

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

  Thereby, since the opposing space | interval of the head sensor 23 and a hitting surface can be shortened, when the center part (vicinity where the cushion member 14 contact | abuts) of a hitting surface is hit | damaged, the hit of the head of the center sensor 10 is carried out. The time from detection by the sensor 13 to detection by the head sensor 23 of the first peripheral sensor 20 to the third peripheral sensor 40 can be shortened. That is, the head sensor 23 of the first peripheral sensor 20 to the third peripheral sensor 40 detects a hit as compared with the case where the central sensor 10 and the first peripheral sensor 20 to the third peripheral sensor 40 are provided with cushion members having the same thickness. Since the time until the time (ie, the time until the necessary information such as signal arrival time and peak level can be acquired) can be shortened, the delay time of sound generation control by the control device 7 can be shortened.

  Further, when the center portion of the striking surface is hit, the vibration of the striking (amplitude of the film member 3a) is larger in the peripheral portion (outside in the radial direction of the shell 2 than the central portion in the film member 3a) compared to the central portion of the striking surface. Therefore, the hit detection sensitivity decreases accordingly.

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

  Further, since the head sensors 13 and 23 are disposed on the back side of the striking surface via the cushion members 14 and 24, even if the head sensors 13 and 23 are hit directly above the head sensors 13 and 23, The impact can be absorbed by the cushion members 14 and 24. Therefore, it is possible to protect the head sensors 13 and 23 from impact of hitting and to suppress the breakage.

  Here, in order to increase the sensitivity of hit detection, it is preferable that the thickness of the cushion members 14 and 24 is set to be thin, and the head sensors 13 and 23 are disposed as close as possible to the hitting surface. However, if the thickness of the cushion members 14 and 24 is reduced and the head sensors 13 and 23 are too close to the hitting surface, the hitting surface is hit hard to hit the head sensors 13 and 23. That is, the cushion members 14 and 24 cannot absorb the impact caused by the impact, and the head sensors 13 and 23 are substantially directly hit. Therefore, the head sensors 13 and 23 are damaged.

  Therefore, it is preferable that the cushion members 14 and 24 are formed to have a thickness that does not contact the head sensors 13 and 23 when the hitting surface is hit hard. In this case, in order to set the thickness of the cushion members 14 and 24 so as not to contact the bottom of the head sensors 13 and 23, first, the cushion members 14 and 24 are placed in the vicinity where the cushion members 14 and 24 abut against the striking surface. The struck with a stick in a detached state, and the maximum deflection amount of the striking surface (film member 3a) is measured. The amount of deflection changes depending on the tension of the hitting surface, but is measured in a state where the hitting surface is stretched with the lowest tension in the assumed range (playable range).

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

  That is, the head sensors 13 and 23 are damaged by forming the cushion members 14 and 24 to have a thickness approximately 1.5 to 2 times the maximum deflection of the hitting surface when the hitting surface is hit hard. This can increase the detection sensitivity.

  In the present embodiment, the maximum deflection amount of the striking surface at the time of striking is 20 mm near the center of the striking surface (near the cushion member 14 abuts), and 14 mm near the periphery (near the cushion member 24 abuts). there were. Therefore, the thickness of the cushion member 14 was set to 35 mm (1.75 times the maximum deflection amount 20 mm), and the thickness of the cushion member 24 was set to 25 mm (1.78 times the maximum deflection amount 14 mm). Thereby, even when the hitting surface is hit hard, it is possible to suppress bottom contact with the head sensors 13 and 23 and to increase the detection sensitivity of the head sensors 13 and 23.

  In this way, since the striking surface is stretched with tension applied to its outer peripheral edge, the maximum deflection amount of the striking surface at the time of striking is large near the center, and the peripheral side is smaller than that near the center. Become. Therefore, according to the maximum deflection amount, the cushion member 14 is formed thicker than the cushion member 24 (the cushion member 24 is formed thinner than the cushion member 14). It can be disposed at a position close to the hitting surface.

  Accordingly, by setting the thickness of the cushion members 14 and 24 in accordance with the deflection amount of the striking surface at the time of impact (in this embodiment, the thickness is set to about 1.75 times the deflection amount), the cushion members 14 and 24 are set. Thus, while the head sensors 13 and 23 are protected, the arrangement positions of the head sensors 13 and 23 from the striking surface (opposite distance from the film member 3a) can be appropriately adjusted.

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

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

  The cushion member 24 has a thickness of 2 ms after a hit signal (peak described later) when the center of the hitting surface is hit is detected by the head sensor 23 for a predetermined time (in this embodiment, the center sensor 10 detects the hit). ) Is set to a thickness that can be detected within. This 2 ms is a scan time by the central sensor 10 described later. By causing the first peripheral sensor 20 to the third peripheral sensor 40 to detect the peak of the hit within this scan time (that is, the presence / absence of the hit and its intensity are detected), the first peripheral sensor 20 to the third peripheral sensor 40 are detected. The hit position near the center of the hitting surface can be detected from the time difference between the peaks detected in step. Therefore, the hitting position can be detected in a shorter time compared to the case where the hitting position near the center of the hitting surface is detected by the central sensor 10 based on the initial half-wave pitch described later.

  Next, a control for performing the performance of the drum sound by calculating the striking position and velocity of the electronic drum 1 according to the sensor output values of the central sensor 10 and the first peripheral sensor 20 to the third peripheral sensor 40. Describe the program.

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

  Note that the first peripheral sensor 20 to the third peripheral sensor 40 have sensor output values of the same hit during the 2 ms wait process (hereinafter referred to as “scan time by the central sensor 10”) from the hit detection by the central sensor 10. The maximum absolute value (hereinafter referred to as “peak”) can be detected by all of the first peripheral sensor 20 to the third peripheral sensor 40 and the central sensor 10 detects a hit, and then the scan by the central sensor 10 is performed. Within the time, it is arranged at a position where the waveform of the first minus value in the impact by the sensor output value of the central sensor 10, that is, the initial half wave can be detected. Specifically, the first peripheral sensor 20 to the third peripheral sensor 40 are disposed at a position “100” in FIG.

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

  When the initial half wave in the central sensor 10 is completely detected within the scan time by the central sensor 10 and the peaks of the first peripheral sensor 20 to the third peripheral sensor 40 due to the same hit are detected, The striking position is calculated by weighting the striking position calculated by the sensor 10 and the striking positions by the first peripheral sensor 20 to the third peripheral sensor 40.

  On the other hand, in the case of hitting near the center of the hitting surface, that is, near the center sensor 10 (inner side from the position “75” in FIG. 3), the pitch of the initial half-wave detected by the center sensor 10 is large, and the center There is a case where it does not fall within the scan time by the sensor 10, and at that time, an accurate hitting position by the central sensor 10 cannot be calculated. That is, the area where the hitting position can be calculated based on the pitch of the initial half-wave detected by the center sensor 10 is limited to the outer peripheral side rather than the vicinity of the center of the hitting surface.

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

  Here, if the distance between the central sensor 10 and the first peripheral sensor 20 to the third peripheral sensor 40 is large, the first peripheral sensor 20 to the third peripheral sensor 40 are detected after the central sensor 10 detects a hit. The time until the hit is detected becomes longer. Accordingly, when the first peripheral sensor 20 to the third peripheral sensor 40 are arranged on the outer peripheral side from the position where the hit can be detected within the scan time by the central sensor 10, the first peripheral sensor 20 to the third peripheral sensor 40 are within the scan time by the central sensor 10. The hit is not detected by the peripheral sensor 20 to the third peripheral sensor 40, and the hit position cannot be calculated. Furthermore, when the vicinity of the center of the hitting surface is hit at the positions where the first peripheral sensor 20 to the third peripheral sensor 40 are disposed, the first peripheral sensor 20 to the third peripheral sensor 40 are within the scan time of the central sensor 10. In addition to being able to calculate the hit position, as described above, the center sensor 10 cannot also calculate the correct hit position. That is, there is an area in which the hitting position cannot be accurately calculated within the scan time by the central sensor 10.

  Therefore, the first peripheral sensor 20 to the third peripheral sensor 40 in the present embodiment, when the hitting surface is hit, after the central sensor 10 detects the hit, the hit within the scan time by the central sensor 10. It is possible to detect and within the scan time by the central sensor 10, it is disposed at a position (position “100” in FIG. 3) where the initial half wave of the hit can be detected. Thereby, even if the hit is near the center of the hitting surface, the hit positions by the first peripheral sensor 20 to the third peripheral sensor 40 can be calculated within the scan time by the central sensor 10. When it is determined that the striking position detected by the first peripheral sensor 20 to the third peripheral sensor 40 is near the center of the hitting surface, the first peripheral sensor 20 to the third peripheral sensor 40 that can be calculated. The striking position is calculated from only the striking position. Thereby, an accurate hitting position can be acquired.

  Further, the calculation of the striking strength (velocity) is performed according to a weighting calculation based on the peak of the central sensor 10 and the peaks of the first peripheral sensor 20 to the third peripheral sensor 40 detected by the striking. Although details will be described later, when a hit is detected by the central sensor 10 and the first peripheral sensor 20 to the third peripheral sensor 40 within the scan time by the central sensor 10, the peak of the central sensor 10 and the first peripheral sensor The velocity is calculated from the 20th to the third peripheral sensor 40 peaks. Thereby, since the velocity is calculated from the central sensor 10 having high hitting sensitivity and the first peripheral sensor 20 to the third peripheral sensor 40, the velocity can be calculated more accurately.

  On the other hand, in the case where no hit is detected by the central sensor 10 within the 2 ms wait process (hereinafter referred to as “scan time by the peripheral sensor”) from the detection of the hit by the first peripheral sensor 20 to the third peripheral sensor 40. The velocity is calculated from the peaks of the first peripheral sensor 20 to the third peripheral sensor 40. As a result, even if the impact is so weak that the central sensor 10 cannot detect the impact at the outer periphery of the impact surface, the velocity is reliably calculated, and a tone generation instruction is issued based on the velocity.

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

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

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

  FIG. 6A is a voltage-time graph of a voltage waveform (an output waveform from the central sensor 10) based on the hit in the central sensor 10. FIG. The vertical axis represents voltage and the horizontal axis represents time. The voltage waveform between the start time Ts of the voltage waveform based on the strike output by the central sensor 10 and the time Te that becomes the zero cross point of the voltage waveform immediately after that is a negative value. This is because the striking surface “bends” in the negative direction when the striking surface of the electronic drum is hit. In the present embodiment, the negative voltage waveform output from time Ts to Te at the start of detection of the hit is referred to as “initial half wave”. In general, the initial half-wave pitch ΔThw detected by the central sensor 10, that is, the time difference between the time Te and the time Ts changes according to the distance between the central sensor 10 and the hitting position. Specifically, the closer the hitting position is to the center sensor 10, the larger the initial half-wave pitch ΔThw, and the farther the hitting position is from the center sensor 10, the smaller the initial half-wave pitch ΔThw. A central sensor hitting position table 72b is a table in which this relationship is calculated from actual measurement values. With reference to Fig.5 (a), the center sensor hitting position table 72b is demonstrated.

  FIG. 5A is a diagram schematically showing the central sensor hitting position table 72b. The central sensor hitting position table 72b is a table in which hitting positions calculated from actual measurement values are stored in accordance with the initial half-wave pitch ΔThw. The initial half-wave pitch ΔThw calculated from the voltage waveform based on the hit in the central sensor 10 is referred to as the initial half-wave pitch ΔThw in the central sensor hitting position table 72b, and the corresponding hit position is acquired. The hitting position is calculated using the acquired hitting position and the hitting position obtained from the first peripheral sensor 20 to the third peripheral sensor 40 described later, and the performance information of the electronic drum 1 is generated based on the calculated hitting position. In addition, each numerical value of the central sensor hitting position table 72b in FIG. 5A is not necessarily limited to this, the material and characteristics of the head 3, the central sensor 10, and the cushion member 14, the arrangement of the central sensor 10, You may set suitably according to the height of the cushion member 14, etc.

  Returning to FIG. The peripheral sensor hitting position table 72c is a table that acquires the hitting position of the electronic drum 1 based on the time difference of hit detection in the first peripheral sensor 20 to the third peripheral sensor 40. Here, the time difference of the hit detection in the 1st periphery sensor 20-the 3rd periphery sensor 40 is demonstrated with reference to FIG.6 (b).

  6B is a voltage-time graph of voltage waveforms in the first peripheral sensor 20, the second peripheral sensor 30, and the third peripheral sensor 40, which are detected in response to a certain hit on the hitting surface of the electronic drum 1. FIG. It is. In each case, the vertical axis represents voltage and the horizontal axis represents time. The time at which the first peripheral sensor 20 detects a peak due to a certain hit is the peak time Tm1, and the time at which the same peripheral peak detected by the second peripheral sensor 30 and the third peripheral sensor 40 is detected. The peak times are Tm2 and Tm3, respectively. The time difference between the peak time Tm1 and the peak time Tm2 is ΔT1, and the time difference between the peak time Tm1 and the peak time Tm3 is ΔT2. The first peripheral sensor 20, the second peripheral sensor 30, and the third peripheral sensor 40 are disposed at equal intervals from the center of the striking surface at a position of “100” (see FIG. 3). When hit, the detected peak times Tm1, Tm2, and Tm3 are equal. On the other hand, when hitting other than the center of the hitting surface, the detected peak times Tm1, Tm2, and Tm3 change according to the hitting position. That is, ΔT1 and ΔT2 change according to the striking position. Therefore, in the present embodiment, with the first peripheral sensor 20 as the base point of the peripheral sensor, the hit position according to the time difference ΔT1, ΔT2 of the hit peak with the second peripheral sensor 30 and the third peripheral sensor 40 is determined from the actual measurement value. What is calculated and tabulated is a peripheral sensor hitting position table 72c. With reference to FIG.5 (b), the periphery sensor hitting position table 72c is demonstrated.

  FIG. 5B is a diagram schematically illustrating the peripheral sensor hitting position table 72c. The peripheral sensor hitting position table 72c stores the hitting positions calculated from the measured values according to the time differences ΔT1 and ΔT2 of the hitting peaks between the first peripheral sensor 20, the second peripheral sensor 30, and the third peripheral sensor 40. Is a table to be played. The time difference ΔT1 and ΔT2 of the hitting peak are referred to as the time difference ΔT1 and ΔT2 of the peripheral sensor hitting position table 72c, and the corresponding hitting position is acquired. Thereby, the hit position by the 1st periphery sensor 20-the 3rd periphery sensor 40 can be acquired rapidly compared with the case where it calculates from time difference (DELTA) T1 and (DELTA) T2 of the peak of a hit each time. The hit position is calculated using the acquired hit position and the hit position obtained from the central sensor 10, and the performance information of the electronic drum 1 is generated based on the calculated hit position. It should be noted that the striking position by the time difference ΔT1 and ΔT2 of the striking peak cannot be calculated on the outer peripheral side from the positions of the first peripheral sensor 20 to the third peripheral sensor 40. This is, for example, on the extension line connecting the time difference ΔT1 and ΔT2 of the hitting peak when hit at the position (position A) of the first peripheral sensor 20 and the center of the hitting surface, and the first peripheral sensor 20. This is because the time difference ΔT1 and ΔT2 of the hitting peak when hitting at a position on the outer peripheral side is the same value. Accordingly, also in the peripheral sensor hitting position table 72c, the first peripheral sensor 20 to the third peripheral position are stored in the storage position in the outer peripheral side of the first peripheral sensor 20 to the third peripheral sensor 40 due to the time differences ΔT1 and ΔT2. The same “100” as the position of the sensor 40 is stored.

  5B is not necessarily limited to this, and the materials and characteristics of the head 3, the first peripheral sensor 20 to the third peripheral sensor 40, and the cushion member 24 are not necessarily limited thereto. The first peripheral sensor 20 to the third peripheral sensor 40, the height of the cushion member 24, and the like are set as appropriate.

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

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

  The sensor value memory 73a is a memory for storing the sensor output values (the unit is none) of the central sensor 10 and the first peripheral sensor 20 to the third peripheral sensor 40 that have been A / D converted. Although not shown, the sensor value memory 73a individually stores the sensor output values of the central sensor 10, the first peripheral sensor 20 to the third peripheral sensor 40. The sensor value memory 73a is initialized with “0” when the electronic drum 1 is powered on and immediately after the initialization process of FIG. In the periodic process of FIG. 8, the sensor output value at the time when the periodic process is executed in the central sensor 10 and the first peripheral sensor 20 to the third peripheral sensor 40 is stored in the corresponding sensor value memory 73a. (FIG. 8, S10).

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

  FIG. 5C is a diagram schematically showing the sensor value ring buffer 73b. The sensor value ring buffer 73b has a central sensor value memory 73b1, a first peripheral sensor value memory 73b2, a second peripheral sensor value memory 73b3, and a third peripheral sensor value memory 73b4, which are associated with each other. Remembered. The central sensor value memory 73b1 is a memory for storing the sensor output value (no unit) of the A / D converted central sensor 10, and the first peripheral sensor value memory 73b2 to the third peripheral sensor value memory 73b4 are respectively , A memory for storing A / D converted sensor output values (no unit) of the first peripheral sensor 20 to the third peripheral sensor 40, when the electronic drum 1 is powered on and initialized in FIG. It is initialized with “0” immediately after the processing is executed. In the periodic process of FIG. 8, the sensor output values at the time when the periodic process is executed in the central sensor 10 and the first peripheral sensor 20 to the third peripheral sensor 40 are the corresponding central sensor value memory 73b1 and the first The data is added to the first peripheral sensor value memory 73b2 to the third peripheral sensor value memory 73b4 (S10 in FIG. 8).

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

  Returning to FIG. The sensor peak value memory 73c is a memory for storing the peak (maximum absolute value) of the sensor output values of the central sensor 10 and the first peripheral sensor 20 to the third peripheral sensor 40. Although not shown, the sensor peak value memory 73c individually stores the peak of each sensor output value of the central sensor 10 and the first peripheral sensor 20 to the third peripheral sensor 40. The value in the sensor peak value memory 73c is initialized to “0” when the electronic drum 1 is powered on and immediately after the initialization process of FIG. Then, in the periodic process of FIG. 8, when a hit is detected by the central sensor 10, the first peripheral sensor 20 to the third peripheral sensor 40, the central sensor 10, the first peripheral sensor 20 to the third sensor from the sensor value ring buffer 73 b. The sensor output value peak in the peripheral sensor 40 is stored in the sensor peak value memory 73c (FIG. 8, S16, S19). Thereafter, the value of the sensor value memory 73a in the central sensor 10, the first peripheral sensor 20 to the third peripheral sensor 40 is compared with the value of the corresponding sensor peak value memory 73c, and the larger one is stored in the sensor peak value memory 73c. Stored (FIG. 8, S21, S25). Velocity due to impact is calculated by weighting calculation based on the values in the sensor peak value memory 73c of the central sensor 10, the first peripheral sensor 20 to the third peripheral sensor 40 (FIGS. 9, S33, 10, and S53).

  The center sensor scan flag 73d is a flag indicating that the scan time by the center sensor 10 is in a 2 ms wait process. The center sensor scan flag 73d is set to OFF, indicating that the scan time by the center sensor 10 is not in progress, when the electronic drum 1 is turned on and immediately after the initialization process of FIG. When the central sensor 10 determines that a hit is detected in the periodic process of FIG. 8, the central sensor scan flag 73d is set to ON (FIG. 8, S17). In the central sensor hit process of FIG. When the scan time of the sensor 10 ends, the central sensor scan flag 73d is set to OFF (FIG. 9, S31).

  The peripheral sensor scan flag 73e is a flag indicating that the scan time by the peripheral sensor is in the 2 ms wait process. The peripheral sensor scan flag 73e is set to OFF indicating that the scan time by the peripheral sensor is not in effect when the electronic drum 1 is turned on and immediately after the initialization process of FIG. Then, in the periodic process of FIG. 8, when it is determined that any one of the first peripheral sensor 20 to the third peripheral sensor 40 has detected a hit, the peripheral sensor scan flag 73e is set to ON (FIG. 8, S20). In the peripheral sensor hitting process of FIG. 10, the peripheral sensor scan flag 73e is set to OFF when the scan time of the first peripheral sensor 20 to the third peripheral sensor 40 is over (FIG. 10, S51). Further, when a hit by the central sensor 10 is detected in a state where the peripheral sensor scan flag 73e is on, the peripheral sensor scan flag 73e is set to off (FIG. 8, S24). Although details will be described later, this is because when the hit by the central sensor 10 is detected within the scan time by the peripheral sensor, the scan time by the peripheral sensor is stopped, the scan time by the central sensor 10 is performed again, and the central sensor 10 This is because the hitting position and velocity are calculated by the central sensor 10 and the first peripheral sensor 20 to the third peripheral sensor 40 after the scan time.

  The central sensor hitting position gain memory 73f is a memory for storing a weighting coefficient for the hitting position by the central sensor 10 used when calculating the hitting position. The central sensor impact position gain memory 73f is initialized to “0” when the electronic drum 1 is powered on and immediately after the initialization process of FIG. In the present embodiment, the central sensor hitting position gain memory 73f stores a ratio (a value between 0 and 1) indicating how much the hitting position by the central sensor 10 is considered in calculating the hitting position. Is remembered as On the other hand, the value obtained by subtracting the value of the central sensor hitting position gain memory 73f from 1 indicates how much the hitting positions by the first peripheral sensor 20 to the third peripheral sensor 40 are considered in calculating the hitting position. It is a ratio (weight coefficient).

  That is, in the central sensor hitting process of FIG. 9, a threshold value as to whether or not the hit positions by the first peripheral sensor 20 to the third peripheral sensor 40 are only hit positions detected by the first peripheral sensor 20 to the third peripheral sensor 40. Is equal to or greater than “75”, “0.5” is set in the central sensor impact position gain memory 73f, and when the impact position by the first peripheral sensor 20 to the third peripheral sensor 40 is smaller than “75”, 0 "is set (FIG. 9, S38, S39). Then, the value of the central sensor hitting position gain memory 73f, the hitting position by the central sensor 10 (that is, the value of the central sensor hitting position memory 73g described later), and the hitting positions by the first peripheral sensor 20 to the third peripheral sensor 40 ( That is, the hitting position is calculated by a weighting calculation using the peripheral sensor hitting position memory 73h) (FIG. 9, S40).

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

  The peripheral sensor hitting position memory 73h is a memory for storing hitting positions acquired by the first peripheral sensor 20 to the third peripheral sensor 40, and the initialization process shown in FIG. 7A is performed when the electronic drum 1 is turned on. It is initialized with “0” immediately after execution. Then, the peak time difference ΔT1 between the first peripheral sensor 20 and the second peripheral sensor 30 and the peak time difference ΔT2 between the first peripheral sensor 20 and the third peripheral sensor 40 calculated from the sensor value ring buffer 73b are calculated as peripheral sensors. The hit position obtained by referring to the hit position table 72c is stored in the peripheral sensor hit position memory 73h (FIG. 9, S36).

  The striking position memory 73i is a memory for storing the striking position calculated based on the detection result of striking the striking surface of the electronic drum 1, and the initialization process shown in FIG. It is initialized with “0” immediately after execution. When the central sensor 10 detects a hit, the hit position is calculated from the hit position by the central sensor 10 and the hit positions by the first peripheral sensor 20 to the third peripheral sensor 40 after the scan time by the central sensor 10 ( FIG. 9, S40).

  On the other hand, when the first peripheral sensor 20 to the third peripheral sensor 40 detect a hit and the central sensor 10 does not detect the hit within the scan time by the peripheral sensor, “100” is stored in the hit position memory 73i. The That is, when the outer periphery of the hitting surface is hit weakly, the first peripheral sensor 20 does not detect the hit while the first peripheral sensor 20 to the third peripheral sensor 40 detect hits. Assuming that the player is hit at the position of the 20th to third peripheral sensors 40 (FIG. 10, S54), an instruction to generate a musical tone is issued based on the hit position. As a result, it is possible to issue a musical sound generation instruction by weakly striking the outer periphery of the hitting surface, and the musical sound generation instruction is not delayed. When the central sensor 10 does not detect a hit, the value stored in the hit position memory 73i is not necessarily limited to “100”, and any value in the range of “100” to “127” can be set. It may be stored.

  The velocity memory 73j is a memory for storing the velocity (striking strength) calculated based on the detection result of the impact on the striking surface of the electronic drum 1, and is initialized when the electronic drum 1 is powered on and in FIG. It is initialized with “0” immediately after the processing is executed. In the central sensor hitting process of FIG. 9, the calculation is performed by weighting the peak of the sensor output values of the central sensor 10 and the first peripheral sensor 20 to the third peripheral sensor 40, which are stored in the sensor peak value memory 73c. The velocity is stored in the velocity memory 73j (S33 in FIG. 9). Further, in the peripheral sensor hitting process of FIG. 10, the calculated velocity is calculated by weighting the peak of the sensor output values of the first peripheral sensor 20 to the third peripheral sensor 40 stored in the sensor peak value memory 73c. It is stored in the memory 73j (S53 in FIG. 10). Then, an instruction to generate a musical tone according to the value in the velocity memory 73j and the value in the hitting position memory 73i is given to the sound source 76 described later (FIGS. 9, S41, 10, and S55).

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

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

  The sound source 76 is a device that controls the tone color and various effects of a musical sound (striking sound) in accordance with an instruction from the CPU 71. The sound source 76 incorporates a DSP (Digital Signal Processor) 76 a that performs arithmetic processing such as filtering of waveform data and effects. The musical sound processed by the sound source 76 is output as an analog musical sound signal.

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

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

  With reference to Fig.7 (a), the initialization process performed by CPU71 of the electronic drum 1 is demonstrated. FIG. 7A is a flowchart of the initialization process. The initialization process is executed immediately after the electronic drum 1 is powered on, and initializes each memory value and flag on the RAM 73 (S1).

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

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

  Next, periodic processing executed by the CPU 71 of the electronic drum 1 will be described with reference to FIGS. In the periodic processing, when the periodic processing is executed, the sensor output values of the central sensor 10 and the first peripheral sensor 20 to the third peripheral sensor 40 are acquired, and when the scan time has passed, the hit position and velocity are calculated. The central sensor hitting process (FIG. 9) or the peripheral sensor hitting process (FIG. 10) is executed to calculate and issue a musical sound generation instruction. Periodic processing is repeatedly executed every 100 μs by interval interrupt processing every 100 μs.

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

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

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

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

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

  After the process of S16, the central sensor scan flag 73d is set to ON, and the scan time is started from 0 (S17). Thereafter, the scan time is counted every time the periodic process is executed. Thereby, the timing of “scan time by the central sensor 10” is started.

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

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

  After the process of S19, the peripheral sensor scan flag 73e is set to ON, and the scan time is started from 0 (S20). Thereafter, the scan time is counted every time the periodic process is executed. Thereby, the timing of “scan time by the peripheral sensor” is started.

  At the start of the scan time by the central sensor 10 or the scan time by the peripheral sensor, the peak of each sensor at the latest 5 ms stored in the sensor value ring buffer 73b is acquired and stored in the sensor peak value memory 73c. Even if the central sensor 10 or the first peripheral sensor 20 to the third peripheral sensor 40 detects a hit, either the first peripheral sensor 20 to the third peripheral sensor 40 or the central sensor 10 hits first. This is because there is a possibility that the peak in the voltage waveform due to the impact is stored in the sensor peak value memory 73c. First, at the start of each scan time, a peak is searched from the value of the sensor value ring buffer 73b, and the peak is stored in the sensor peak value memory 73c. Thereafter, in the processing of S21 and S25 described later, each time the periodic processing is executed during each scan time, the value of the sensor value memory 73a in which the sensor output value at the time when the periodic processing is executed is stored. The value in the sensor peak value memory 73c is compared, and the value having the largest absolute value is stored in the sensor peak value memory 73c. Thereby, the peak of the sensor output value before and after the scan time by the central sensor 10 is stored in the sensor peak value memory 73c.

  On the other hand, when none of the first peripheral sensor 20 to the third peripheral sensor 40 detects a hit (S14: No), the processing of S18 to S20 is skipped.

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

  In the process of S12, when the peripheral sensor scan flag 73e is on (S12: Yes), it is confirmed whether the central sensor 10 has detected a hit (S23). In addition, the method of confirming whether the center sensor 10 detected the hit is the same as the process of S13. If the central sensor 10 detects a hit (S23: Yes), the peripheral sensor scan flag 73e is set to OFF, the scan time is stopped (S24), and the processes after S16 are performed. In other words, when a hit by the central sensor 10 is detected during the scan time by the peripheral sensor, the scan time by the central sensor 10 is started.

  That is, the center of the striking surface has a larger deformation amount (deflection amount) of the striking surface than the peripheral portion of the striking surface, so the central sensor 10 disposed at the center of the striking surface is disposed at the peripheral portion of the striking surface. Compared with the first peripheral sensor 20 to the third peripheral sensor 40, the range of sensor output values with respect to impact is wide and the detection sensitivity of impact is good. Therefore, even when the first peripheral sensor 20 to the third peripheral sensor 40 detect a hit before the central sensor 10, if the central sensor 10 detects a hit within the scan time by the peripheral sensor, the scan time by the central sensor 10 Then, the velocity is calculated based on the hit detection results of the central sensor 10 and the first peripheral sensor 20 to the third peripheral sensor 40. Therefore, even when the first peripheral sensor 20 to the third peripheral sensor 40 detect a hit before the central sensor 10, the first peripheral sensor 20 to the third peripheral sensor 40 detect the hit after the central sensor 10. Even in this case, the velocity can be calculated using the detection result of the central sensor 10 with good sensitivity.

  In this case, the musical sound generation instruction is delayed by the time from the detection of the first peripheral sensor 20 to the third peripheral sensor 40 to the detection of the central sensor 10. However, since the period during which it is determined whether or not the hit of the central sensor 10 is detected is within the scan time by the peripheral sensor from the detection of the hit of the first peripheral sensor 20 to the third peripheral sensor 40, the generation of the musical sound The instruction delay time can be stopped within a scan time (ie, 2 ms) by the peripheral sensor. That is, the delay time of the musical sound generation instruction can be stopped within the range of the design value by adjusting the time measured by the peripheral sensor.

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

  Next, with reference to FIG. 9, the center sensor hitting process (FIG. 8, S22) executed during the scan time by the center sensor 10 will be described. The central sensor hitting process calculates the hit position and velocity from the values of the sensor peak value memory 73c of the central sensor 10 and the first peripheral sensor 20 to the third peripheral sensor 40 and the value of the sensor value ring buffer 73b. A musical sound generation instruction corresponding to the position and velocity is given to the sound source 76, and the musical sound of the electronic drum 1 is generated.

  First, in the central sensor impact process, it is confirmed whether the scan time is 2 ms or more (S30). The scan time by the central sensor 10 at 2 ms after the central sensor 10 detects a hit is during the so-called “weight processing” in which the output value of each sensor by the hit is monitored and the hitting position and velocity by the hit are not calculated. Therefore, it is confirmed whether the scan time has elapsed.

  When the scan time is 2 ms or more (S30: Yes), the scan time by the central sensor 10 is ended, so the central sensor scan flag 73d indicating that the scan time by the central sensor 10 is being set is set to OFF, Scan time measurement is stopped (S31).

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

Here, gain_c, gain_s1, gain_s2, and gain_s3 are gain constants, which are “0.3”, “0.2”, “0.2”, and “0.2”, respectively. Further, gain_Mix_v is a value set by the user, and is a value set by an input device (not shown) of the electronic drum 1. The velocity Vl calculated by Equation 1 is stored in the velocity memory 73j. Each gain constant is not necessarily limited to the value described above, and is appropriately set according to the size and material of the hitting surface, the sensitivity of the central sensor 10 and the first peripheral sensor 20 to the third peripheral sensor 40, and the like. May be.

After the process of S33, an initial half wave due to the strike of the central sensor 10 is acquired from the value of the sensor value ring buffer 73b, and the corresponding strike is made with reference to the central sensor hit position table 72b with the pitch ΔThw of the initial half wave The position is stored in the central sensor hitting position memory 73g (S34). Specifically, referring to the value of the central sensor value memory 73b1 of the sensor value ring buffer 73b, the position that becomes the minimum value is acquired. First, from the position, the value in the central sensor value memory 73b1 of the sensor value ring buffer 73b is referred in the backward direction, and the position where the value becomes 0 is acquired. That is, this time is time Ts in FIG.

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

  With reference to the time difference between this time Ts and time Te, that is, the value of the initial half-wave pitch ΔThw, the central sensor impact position table 72b is referred to, and the corresponding impact position is stored in the central sensor impact position memory 73g.

  After the process of S34, the detection time of hitting of the first peripheral sensor 20 to the third peripheral sensor 40 is acquired from the value of the sensor value ring buffer 73b (S35). Specifically, referring to the values of the first peripheral sensor value memory 73b2, the second peripheral sensor value memory 73b3, and the third peripheral sensor value memory 73b4 of the sensor value ring buffer 73b, a position that is the minimum value (ie, the figure) 5 (c) “No.”) is acquired. Then, by multiplying the difference between the position and the current storage position of the sensor value ring buffer 73b (that is, the storage position stored in S10 of FIG. 8) by 100 μs, the time that becomes the minimum value, that is, FIG. Peak times Tm1, Tm2, and Tm3 in (b) are calculated.

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

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

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

  On the other hand, when the value of the peripheral sensor hitting position memory 73h is “75” or more, that is, when it is away from the center of the hitting surface of the electronic drum 1, “0.5” is stored in the central sensor hitting position gain memory 73f. Is set, and the hitting position by the central sensor 10 is taken into consideration in the calculation of the hitting position by weighting calculation described later. The hit position by the central sensor 10 is accurately calculated if the position is “75” or more, and the hit positions by the first peripheral sensor 20 to the third peripheral sensor 40 are less than “100”. The hitting position is accurately calculated. Therefore, by calculating the striking position by combining the striking position by the central sensor 10 and the striking positions by the first peripheral sensor 20 to the third peripheral sensor 40, it is possible to acquire a highly precise striking position. In this case, the value set in the central sensor hitting position gain memory 73f is not necessarily limited to “0.5”, and may be set as appropriate according to the size and material of the hitting surface.

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

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

  If the test mode flag 73k is ON in the process of S32 (S32: No), the values in the sensor peak value memory 73c of the central sensor 10 and the first peripheral sensor 20 to the third peripheral sensor 40 are included in the MIDI SysEx message. Is output (S42). If the scan time is shorter than 2 ms in the process of S30, the processes of S31 to S42 are skipped. Then, after the processes of S30, S41, and S42, the central sensor hitting process ends, and the process returns to the regular process of FIG.

  Next, referring to FIG. 10, a peripheral sensor hitting process (FIG. 8) that is executed when no hit is detected by the central sensor 10 during a scan time by the peripheral sensor, such as when the outer peripheral side of the hitting surface is weakly hit. , S26) will be described. In the peripheral sensor hitting process, the hitting position and velocity are calculated from the values of the sensor value ring buffer 73b of the first peripheral sensor 20 to the third peripheral sensor 40. In this case, the striking position is “100 (fixed value)” (see FIG. 3). Then, an instruction to generate a musical sound according to the hitting position and velocity is given to the sound source 76, and the musical sound of the electronic drum 1 is generated.

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

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

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

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

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

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

  If no hit is detected by the central sensor 10 within the scan time by the peripheral sensor, such as a weak hit that the central sensor 10 cannot detect at the peripheral portion of the hitting surface, the first peripheral sensor 20- The third peripheral sensor 40 detects the weak hit and issues a musical sound generation instruction. In other words, after the hit of the first peripheral sensor 20 to the third peripheral sensor 40 is detected, if no hit is detected by the central sensor 10 within the scan time by the peripheral sensor, without waiting for the hit detection by the central sensor 10. Music generation instructions are given. Therefore, in this case as well, the musical sound generation instruction is not delayed.

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

  From the above, when the hit position by the first peripheral sensor 20 to the third peripheral sensor 40 is between 0 and 75, the hit is due to the center of the hitting surface of the electronic drum 1, and the center sensor 10 has the initial half-wave pitch ΔThw. Therefore, the hitting position is calculated only by the hitting positions of the first peripheral sensor 20 to the third peripheral sensor 40. That is, “0” is set to pre_gain_c (the value of the central sensor hitting position gain memory 73f) of Expression 2. And when the hit position by the 1st periphery sensor 20-the 3rd periphery sensor 40 is between 75-100, it is the range in which a hit position is detected by the center sensor 10 and the 1st periphery sensor 20-the 3rd periphery sensor 40. Therefore, the hitting position is calculated by the weighting calculation of both. At this time, “0.5” is set to pre_gain_c (the value of the central sensor hitting position gain memory 73f) of Expression 2. Note that the value of pre_gain_c set in this case is not necessarily limited to “0.5”, and may be set as appropriate according to the size of the hitting surface, the material, and the like.

  And when the hit position by the 1st periphery sensor 20-the 3rd periphery sensor 40 is 100 or more, ie, an outer periphery rather than the position (position "100" of FIG. 3) of the 1st periphery sensor 20-the 3rd periphery sensor 40 On the side. In the present embodiment, as shown in FIG. 5B, when the hit position by the first peripheral sensor 20 to the third peripheral sensor 40 is on the outer peripheral side from the first peripheral sensor 20 to the third peripheral sensor 40, the first peripheral sensor The position of “100” is the same as the positions of the 20th to third peripheral sensors 40. On the other hand, since the hit position by the central sensor 10 is obtained accurately, the hit position is calculated by weighting calculation of both.

  When the central sensor 10 detects a hit before the first peripheral sensor 20 to the third peripheral sensor 40, generation of a musical tone is instructed after a scan time by the central sensor 10 of 2 ms. Even when the first peripheral sensor 20 to the third peripheral sensor 40 detect a hit before the central sensor 10 and the central sensor 10 does not detect a hit after that, the generation of a musical tone is performed after the scan time by the peripheral sensor of 2 ms. Instructed. When the first peripheral sensor 20 to the third peripheral sensor 40 detect an impact before the central sensor 10 and then the central sensor 10 detects an impact, a maximum scan time of 4 ms (scan time by the central sensor 10 + peripheral sensor) The tone generation is not instructed until after the scan time. However, even in the prior art, generation of a musical sound is instructed after a scan time of 2 ms after the central sensor 10 detects a hit. Also in this embodiment, the point that generation of a musical tone is instructed after a scan time by the central sensor 10 of 2 ms after the central sensor 10 detects a hit is the same as the prior art. Before the center sensor 10 detects a hit, the points from which the 1st periphery sensor 20-the 3rd periphery sensor 40 detect a hit differ. Therefore, after the hit is detected by the central sensor 10 or the first peripheral sensor 20 to the third peripheral sensor 40, the hit position and velocity after the scan time by the central sensor 10 and / or the scan time by the peripheral sensor, that is, after a maximum of 4 ms. Therefore, the musical sound generation instruction is not delayed. Therefore, it is possible to play the electronic drum 1 with good responsiveness to impact.

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

  As described above, the electronic drum 1 according to the present embodiment includes the central sensor 10 disposed in the center of the striking surface and the first peripheral sensor 20 to the third peripheral sensor 40 disposed in the periphery of the striking surface. And is configured. Further, the first peripheral sensor 20 to the third peripheral sensor 40 are arranged at equal intervals on the circumference with the center sensor 10 as the center of the circle, and when any position within the circumference is hit, The first peripheral sensor 20 to the third peripheral sensor 40 are all disposed at a position where a hit can be detected within a scan time of the central sensor 10 of 2 ms after the central sensor 10 detects a hit. Then, the velocity (striking strength) and the striking position are calculated according to each sensor output value detected by each sensor by striking the striking surface of the electronic drum 1, and based on the calculated velocity and striking position, Music generation instructions are given.

  First, the velocity is calculated based on the hitting peaks detected by the central sensor 10 and the first peripheral sensor 20 to the third peripheral sensor 40. Specifically, when the central sensor 10 detects a hit before the first peripheral sensor 20 to the third peripheral sensor 40 by hitting the hitting surface of the electronic drum 1, the central sensor 10 The scan time is measured, and after the end of the scan time, the velocity is calculated based on the hit peaks detected by the central sensor 10 and the first peripheral sensor 20 to the third peripheral sensor 40.

  In this way, the velocity is calculated based on the hitting peaks detected by the central sensor 10 and the first peripheral sensor 20 to the third peripheral sensor 40, so that the hitting sensitivity distribution on the hitting surface is made substantially uniform. It is possible to eliminate so-called hot spots in which the hitting sound is unusually loud at the center of the hitting surface where the center sensor 10 is located. Further, as a result of the formation of a large hitting surface, even if the time difference in hit detection between the central sensor 10 and the first peripheral sensor 20 to the third peripheral sensor 40 becomes large, the velocity is calculated by the first peripheral sensor 20. When the central sensor 10 detects a hit prior to the third peripheral sensor 40, it is performed after the scan time (that is, 2ms) from the detection of the hit of the central sensor 10, so that the musical sound generation instruction is not delayed. .

  If no hit is detected by the central sensor 10 within the scan time by the peripheral sensor, such as a weak hit that the central sensor 10 cannot detect at the peripheral portion of the hitting surface, the first peripheral sensor 20- The third peripheral sensor 40 detects the weak hit and issues a musical sound generation instruction. In other words, after the hit of the first peripheral sensor 20 to the third peripheral sensor 40 is detected, if no hit is detected by the central sensor 10 within the scan time by the peripheral sensor, without waiting for the hit detection by the central sensor 10. Music generation instructions are given. Therefore, in this case as well, the musical sound generation instruction is not delayed.

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

  The first peripheral sensor 20 to the third peripheral sensor 40 are within the scan time by the central sensor 10 of 2 ms after the central sensor 10 detects a hit, regardless of which position in the circumference is hit. All of the first peripheral sensor 20 to the third peripheral sensor 40 are disposed at positions where a hit can be detected. Therefore, the detection of hits by the first peripheral sensor 20 to the third peripheral sensor 40 is performed within the scan time by the central sensor 10, and the first peripheral sensor 20 to the first peripheral sensor 20 by the first peripheral sensor 20 to the third peripheral sensor 40 are detected. 3 The hit position within the circumference where the peripheral sensor 40 is disposed can be calculated. On the other hand, based on the initial half-wave pitch ΔThw detected by the central sensor 10, the hitting position of the peripheral portion of the hitting surface is calculated. Then, according to the striking position indicated by the striking position calculated by the first peripheral sensor 20 to the third peripheral sensor 40, the striking position obtained from the first peripheral sensor 20 to the third peripheral sensor 40 and the central sensor 10 are obtained. The hitting position is calculated by weighting the hitting position. Since the hitting position is calculated by this weighting calculation, the hitting position can be calculated more accurately.

  Here, in the first peripheral sensor 20 to the third peripheral sensor 40, when the hitting surface is hit, the peak due to the same hit is within the scan time by the central sensor 10 of 2 ms after the central sensor 10 detects the hit. Is disposed at a position (a position “100” in FIG. 3) that can be detected by all of the first peripheral sensor 20 to the third peripheral sensor 40. Therefore, the detection by the first peripheral sensor 20 to the third peripheral sensor 40 is performed within the scan time by the central sensor 10, and the first peripheral sensor 20 to the first peripheral sensor 40 in the circumference where the third peripheral sensor 40 is disposed. The hitting position by the peripheral sensor 20 to the third peripheral sensor 40 can be calculated. On the other hand, based on the initial half-wave pitch ΔThw detected by the central sensor 10, the hit position by the central sensor 10 is calculated.

  Here, the first peripheral sensor 20 to the third peripheral sensor 40 have their initial half-wave pitch ΔThw within the scan time of the central sensor 10 after the central sensor 10 detects the hit when the hitting surface is hit. It is arrange | positioned in the position which can detect. Therefore, when a position outside the circumference is hit, the central sensor 10 can detect the initial half-wave pitch ΔThw within the scan time by the central sensor 10, and based on this, the hit position by the central sensor 10 is calculated. The The hitting position is calculated by weighting the hitting position by the central sensor 10 and the hitting positions by the first peripheral sensor 20 to the third peripheral sensor 40. On the other hand, when the vicinity of the center of the hitting surface of the electronic drum 1 is hit within the circumference, the center sensor 10 may not be able to detect the initial half-wave pitch ΔThw completely. Therefore, when the hit position by the first peripheral sensor 20 to the third peripheral sensor 40 is near the center of the hitting surface of the electronic drum 1 (that is, a position of “75” or less), the hit position after the scan time by the central sensor 10. In the calculation, the hit position by the first peripheral sensor 20 to the third peripheral sensor 40 is set as the hit position. Therefore, even when the central sensor 10 cannot completely detect the initial half-wave pitch ΔThw, it is possible to calculate the striking position within the scan time of the central sensor 10.

  As described above, the hitting position within the circumference has the peak time difference ΔT1 between the first peripheral sensor 20 and the second peripheral sensor 30 and the peak time difference ΔT2 between the first peripheral sensor 20 and the third peripheral sensor 40 in the periphery. Since it is calculated with reference to the sensor hitting position table 72c, the hitting position outside the circumference is calculated with reference to the pitch ΔThw of the initial half wave detected by the central sensor 10 with reference to the central sensor hitting position table 72b. The hit positions inside and outside the circumference can be calculated based on the hit detection result within the scan time by the central sensor 10. Therefore, even when the striking surface is large, the striking position can be calculated quickly, so that the musical sound generation instruction is not delayed.

  When only the center sensor 10 is used to detect the impact strength (velocity), a so-called hot spot appears near the center of the hitting surface. Further, when the hitting surface is weakly hit, there is a possibility that the hit cannot be detected. In order to reduce this, the first peripheral sensor 20 to the third peripheral sensor 40 are added in the present embodiment.

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

  Although the present invention has been described based on the embodiments, the present invention is not limited to the above-described embodiments, and various improvements and modifications can be easily made without departing from the spirit of the present invention. Can be inferred.

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

  In the said embodiment, the case where the cushion member 24 of the 1st periphery sensor 20-the 3rd periphery sensor 40 was formed with the same elastic material as the cushion member 14 of the center sensor 10 was demonstrated. However, it is not necessarily limited to this. For example, when the cushion member 24 is formed of an elastic material such as sponge, rubber, or thermoplastic elastomer, it is preferable to use an elastic material having a higher hardness than the cushion member 14. Thereby, when the central part of the hitting surface is hit, it is possible to shorten the time from when the center sensor 10 detects the hit until the first peripheral sensor 20 to the third peripheral sensor 40 detect it. Control delay time can be shortened.

  In the above embodiment, the thickness of the cushion member 24 of the first peripheral sensor 20 to the third peripheral sensor 40 is made thinner than the thickness of the cushion member 14 of the central sensor 10 (the facing distance between the head sensor 23 and the hitting surface is shortened). The case where the time until the head sensor 23 of the first peripheral sensor 20 to the third peripheral sensor 40 detects a hit is shortened. However, it is not necessarily limited to this. For example, the cushion member 14 and the cushion member 24 may be formed with the same thickness (or the cushion member 24 is formed thicker than the cushion member 14).

  In this case, by increasing the hardness of the material of the cushion member 24 (the cushion member 24 is made of a material that can easily transmit the vibration of the impact), the head sensors 23 of the first peripheral sensor 20 to the third peripheral sensor 40 The time until the hit is detected can be shortened. That is, at least the first peripheral sensor 20 to the third peripheral sensor 40 may be configured so that the transmission time of the hit signal when hitting the hitting surface is shorter than that of the center sensor 10, and the means is not limited. Thereby, when the central part of the hitting surface is hit, it is possible to shorten the time from when the center sensor 10 detects the hit until the first peripheral sensor 20 to the third peripheral sensor 40 detect it. Control delay time can be shortened (musical sound generation instruction delay can be shortened).

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

  In the said embodiment, the center sensor 10 and the 1st periphery sensor 20-the 3rd periphery sensor 40 shall be comprised from a piezoelectric element. However, the present invention is not necessarily limited to this, and can be applied to the central sensor 10 and the first peripheral sensor 20 to the third peripheral sensor 40 as long as they can detect the hitting of the hitting surface, such as an acceleration sensor or a pressure sensor.

  In the said embodiment, the case where the hitting surface (film | membrane member 3a) was formed in disk shape was demonstrated. However, the present invention is not necessarily limited to this, and the striking surface may be formed in a rectangular shape, a polygonal shape, or a shape combining curves and straight lines. That is, regardless of the shape of the striking surface, as in the present embodiment, one central sensor 10 is arranged at equal intervals along the circumference with the central sensor 10 as the center of the circle. What is necessary is just to arrange | position the at least 3 1st periphery sensor 20-3rd periphery sensor 40 provided in the area | region formed as a hitting surface.

  That is, the hit position in the circumference where the first peripheral sensor 20 to the third peripheral sensor 40 are arranged is detected from the time difference between the peaks detected by the first peripheral sensor 20 to the third peripheral sensor 40. it can. Further, the hit position outside the circumference where the first peripheral sensor 20 to the third peripheral sensor 40 are arranged can be detected by the detection waveform of the hit signal by one central sensor. Therefore, even if the hitting surface is formed in a rectangular shape, a polygonal shape, or a shape that combines a curve and a straight line, the hit position from the center of the hitting surface is determined by the central sensor 10 and the first peripheral sensor 20-the first. 3 The peripheral sensor 40 can detect appropriately.

  In this case, the configuration may be such that the central sensor 10 is disposed at a position off the center, and at least the first peripheral sensor 20 to the third peripheral sensor 40 are equally spaced on the circumference centered on the central sensor 10. The configuration may be such that it is arranged in the above. Thereby, the calculation of the hitting position can be appropriately performed according to the detection results of the central sensor 10 and the first peripheral sensor 20 to the third peripheral sensor 40.

  In the above embodiment, the first peripheral sensor 20 to the third peripheral sensor 40 are arranged at equal intervals along a circumference with the central sensor 10 as the center of the circle. However, the present invention is not necessarily limited to this, and the first peripheral sensor 20 to the third peripheral sensor 40 are not on the circumference centered on the central sensor 10 but in a polygonal shape or an elliptical shape surrounding the central sensor 10. It may be arranged on a line or may be arranged at unequal intervals. In this case, the perimeter sensor hitting position table 72c corresponding to such an arrangement may be created by actual measurement or the like to calculate the hitting position. In addition, each gain constant in Formula 1 may be set as appropriate by actual measurement or the like to calculate the velocity.

  In the above embodiment, one central sensor 10 is arranged at the center of the hitting surface. However, the present invention is not necessarily limited to this, and two or more central sensors 10 may be provided. In that case, instead of the hit detection result by one central sensor 10 in the above-described embodiment, an average value of hit detection results by a plurality of central sensors 10 may be used for calculation of velocity and hit position.

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

  Two peripheral sensors may be provided. Even in this case, the striking position in the linear direction connecting the two peripheral sensors can be detected. The striking position can be calculated by weighting the striking position obtained from the two peripheral sensors and the striking position obtained from the initial half-wave pitch ΔThw of the central sensor 10. However, the striking position in the direction intersecting the straight line connecting the two peripheral sensors cannot be detected.

  Further, one peripheral sensor may be provided. In this case, the peripheral sensor is a single ring sensor with the center sensor 10 as the center of the circle (the sensor itself is ring-shaped, or one sensor that detects vibration of a ring-shaped member that contacts the head). Sensor). The velocity in this case is calculated by a weighting operation between the peak value of the hit detected by the central sensor 10 and the peak value of the hit detected by the ring sensor. The striking position is first calculated based on the time difference between the striking peak detected by the ring sensor and the striking peak detected by the central sensor 10 (hereinafter referred to as “striking position due to time difference”). Thereby, the striking position within the circumference where the ring sensor is disposed can be calculated.

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

  Thus, the hit position within the circumference where the ring sensor is arranged is calculated by the time difference between the hit peak detected by the ring sensor and the hit peak detected by the central sensor 10, and By calculating the striking position based on the initial half-wave pitch ΔThw of the central sensor 10, the striking positions inside and outside the circumference can be calculated based on the hit detection result within the scan time by the central sensor 10. Therefore, even when the striking surface is large, the striking position can be calculated quickly, so that the musical sound generation instruction is not delayed.

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

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

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

  From the above, it was obtained from the hit position obtained from a plurality of sensors (difference or ratio of hit detection time or hit intensity) of the center sensor 10 and at least one peripheral sensor, and the initial half wave of the center sensor 10. The hitting position can be calculated by weighting calculation with the hitting position.

  In the above embodiment, both the scan time by the central sensor 10 and the scan time by the peripheral sensor are 2 ms. However, the present invention is not necessarily limited to this, and the time counting time may be 2 ms or more or 2 ms or less depending on the size of the hitting surface and the material of the hitting surface. Moreover, the time measured by the scan time by the central sensor 10 and the scan time by the peripheral sensor may be different. For example, since the peak of the central sensor 10 is slower than the first peripheral sensor 20 to the third peripheral sensor 40, the scan time is lengthened, and the peak of the first peripheral sensor 20 to the third peripheral sensor 40 is early. The scan time may be shortened.

  In the above embodiment, when a hit by the central sensor 10 is detected during the scan time by the peripheral sensor, the scan time by the peripheral sensor is stopped and the scan time by the central sensor 10 is started. However, the present invention is not necessarily limited to this. Even when a hit by the central sensor 10 is detected during the scan time by the peripheral sensor, the scan time by the central sensor 10 is not performed, and after the scan time by the peripheral sensor, The velocity and striking position may be calculated from the obtained value of the sensor value ring buffer 73b and the value of the sensor peak value memory 73c, and a musical sound generation instruction may be issued. In this case, with respect to velocity, the value in the sensor peak value memory 73c of the central sensor 10 obtained within the scan time by the peripheral sensors may be used as the peak value of the central sensor 10.

  In addition, with respect to the striking position, that any one of the first peripheral sensor 20 to the third peripheral sensor 40 detects the striking first means that the first peripheral sensor 20 to the third peripheral sensor 40 are more sensitive than the central sensor 10. Since a close position is considered to have been hit, a predetermined position from an intermediate position (position “50”) to the outermost periphery (position “127”) between the central sensor 10 and the first peripheral sensor 20 to the third peripheral sensor 40 (For example, the position “100”) may be set as the hitting position. Alternatively, the difference in time from the start time of the initial half wave of the central sensor 10 obtained during the scan time by the peripheral sensor to the end of the scan time by the peripheral sensor is defined as the pitch ΔThw of the initial half wave of the central sensor 10, and Equation 2 The pre_gain_c (that is, the value of the central sensor hitting position gain memory 73f) is set to a larger value than usual (for example, 0.6), and the hitting position may be calculated by the weighting calculation of Formula 2. This eliminates the wait for the scan time by the central sensor 10, thereby further reducing the delay in the musical sound generation instruction and increasing the responsiveness to impact.

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

  In the above embodiment, when the hit position calculated by the first peripheral sensor 20 to the third peripheral sensor 40 is “75” or more, the hit position by the central sensor 10 and the first peripheral sensor 20 to the third peripheral sensor 40. The hitting position was calculated by weighting the hitting position with the hit position. When the hitting position was smaller than “75”, the hitting position was calculated using only the hitting positions calculated by the first peripheral sensor 20 to the third peripheral sensor 40. However, the present invention is not necessarily limited to this, and only the striking position calculated by the first peripheral sensor 20 to the third peripheral sensor 40 is used to calculate the striking surface area for calculating the striking position and the striking calculated by the central sensor 10. It is good also as a structure which adjoins the area | region of the hitting surface which calculates a striking position only by a position.

  In the above embodiment, the threshold for determining whether or not the hitting position is calculated only at the hitting positions detected by the first peripheral sensor 20 to the third peripheral sensor 40 is set to the position “75”. However, the present invention is not necessarily limited to this, and the boundary value is “75” or less according to the hitting detection characteristics of the central sensor 10 and the first peripheral sensor 20 to the third peripheral sensor 40, such as the size and material of the hitting surface. Or a value greater than or equal to “75”.

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

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

  In the above embodiment, the hitting position is obtained by referring to the peripheral sensor hitting position table 72c with the time difference ΔT1, ΔT2 of the hitting peak between the first peripheral sensor 20, the second peripheral sensor 30, and the third peripheral sensor 40. To do. However, the present invention is not necessarily limited to this, and the striking position may be obtained by calculation from the time difference ΔT1, ΔT2 of the striking peak. In that case, since the peripheral sensor impact position table 72c can be omitted, the size of the ROM 72 can be reduced.

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

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

  In the above-described embodiment, the hitting position is acquired from the hitting detection time difference of the first peripheral sensor 20 to the third peripheral sensor 40. However, the present invention is not necessarily limited to this, and the striking position may be acquired based on a striking detection time difference between the first peripheral sensor 20 to the third peripheral sensor 40 and the central sensor 10. In that case, what is necessary is just to set it as the structure which adds the impact position according to the time difference of the peak of the center sensor 10 and the 1st periphery sensor 20-the 3rd periphery sensor 40 to the periphery sensor impact position table 72c.

1 Electronic drum (electronic percussion instrument)
3a Membrane member (striking surface)
7 Control device 10 Central sensor (part of impact sensor)
20 1st surrounding sensor (a part of surrounding sensor, a part of impact sensor)
30 Second peripheral sensor (part of peripheral sensor, part of impact sensor)
40 Third peripheral sensor (part of peripheral sensor, part of impact sensor)
S17, S30, S31 First weight means, third weight means S20, S50, S51 Second weight means S33, S53 Strength calculation means S41, S55 Sound generation instruction means

Claims (4)

In an electronic percussion instrument comprising a striking surface and a striking sensor for detecting striking on the striking surface,
The impact sensor is configured to include a center sensor disposed in a central portion of the striking surface and a peripheral sensor disposed in a peripheral portion of the striking surface,
First weight means for executing a weight process for a first predetermined time from detection of hitting by the central sensor when the central sensor detects hitting prior to the peripheral sensor;
Second weight means for executing a weight process for a second predetermined time from the hit detection of the peripheral sensor when the peripheral sensor detects hit before the central sensor;
When the first weight means is activated, the impact strength is calculated based on the detection results of the central sensor and the peripheral sensor after the end of the weight processing by the first weight means, and when the second weight means is activated, A strength calculating means for calculating a striking strength based on a detection result of the peripheral sensor when the central sensor does not detect a striking within a period of the weight processing by the second weighting means;
An electronic percussion instrument comprising sound generation instruction means for instructing sound generation of a percussion sound based on the batting intensity calculated by the intensity calculation means. When the central sensor detects a hit within the period of the weight processing by the second weight means during the operation of the second weight means, the weight processing for the third predetermined time is executed after the hit detection of the central sensor. With 3 weight means,
2. The electronic apparatus according to claim 1, wherein the strength calculating means calculates a striking strength based on detection results of the central sensor and the peripheral sensor after completion of the weight processing by the third weight means. Percussion instrument.   The electronic percussion instrument according to claim 2, wherein the first predetermined time and the third predetermined time are the same time.   When the hitting surface is viewed in plan, the hitting surface is formed in a circular shape, the center sensor is disposed at the center of the hitting surface, and the peripheral sensor is a circle centered on the center sensor. The electronic percussion instrument according to any one of claims 1 to 3, wherein at least three are arranged at equal intervals on the circumference.

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