JP4110691B2 - Keyboard instrument sensor data conversion apparatus and sensor data conversion method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sensor data conversion device and a sensor data conversion method for a keyboard musical instrument, and particularly to a keyboard musical instrument capable of performing an automatic performance, and outputs the key sensor or pedal sensor for detecting the operating state of the key or pedal. The present invention relates to a sensor data conversion device and a sensor data conversion method for a keyboard instrument for converting a detection signal or detection data (sensor data) corresponding to the detection signal.
[0002]
[Prior art]
In the performance of the piano, when the performer depresses the key, the damper moves away from the string in conjunction with this, and the hammer rotates and the string is struck. When the key is released, the damper touches the string and the sound is muted. As described above, a musical tone is usually generated by a series of operations of key pressing → stringing → key release → mute.
For this reason, in an automatic piano that performs automatic performance, performance information is generated and recorded based on the series of operations described above, and the operation of keys or pedals is controlled based on the read performance information during playback. Is called.
In the control of the key or pedal in this case, based on the performance information, the solenoid, which is an actuator, is excited on one side to drive the key, and the hammer rotates in response to hitting the string, and the solenoid is turned on the other side. Excitation is applied to drive the pedal, and the sound is extended (sustained), weak (softened), or muted (muted).
[0003]
By the way, in such an automatic piano, there is known a mute automatic piano that can perform a normal performance in which a string is struck when a key is pressed during performance recording and a mute performance in which a string is not struck even when the key is pressed. Yes.
This automatic mute piano is provided with a mechanism for preventing further rotation of the hammer assembly before the hammer rotated by pressing the key hits the string. In a mute performance using such a mute mechanism, instead of generating a stringed sound, the operation of a key or the like is detected by a sensor, and a musical tone having a pitch and strength corresponding to the key depression is generated electronically. It can be done.
In a conventional automatic mute piano, for example, a sensor such as an optical sensor is arranged below each key, and a key sensor method is employed in which the sensor detects the timing and speed of operation of the shutter attached to the lower surface of the key. ing.
For example, Japanese Patent Laid-Open No. 9-54584 discloses an automatic piano technique using a continuous key sensor that continuously detects the key position.
[0004]
[Problems to be solved by the invention]
JP-A-9-54584 In In this case, since the output bit length of the A / D converter for A / D converting the output signal of the continuous key sensor is fixed, it is saturated when the output signal level of the continuous key sensor is too large with respect to the output bit length. This causes the problem of end up. On the contrary, when the output signal level of the continuous key sensor is too small with respect to the output bit length, there arises a problem that the effective data dynamic range is reduced. In order to cope with this, if the output bit length is increased, a new problem arises that the RAM capacity in the subsequent data processing system increases. In addition, the processable bit length of the downstream processor is usually 2 ⁿ Therefore, when the output bit length is increased, the processable bit length is at least doubled at once.
[0005]
On the other hand, a method of securing the dynamic range by optimizing the characteristics of the key sensor according to the output bit length of the A / D converter at the time of shipment from the factory is also conceivable, but it is impossible to cope with aging and aging. It becomes.
Accordingly, a first object of the present invention is to obtain sensor data or a sensor output signal having a dynamic range appropriate for the bit length used in the processing system without increasing the RAM capacity of the subsequent data processing system. An object of the present invention is to provide a sensor data conversion device, a sensor data conversion method, a sensor signal conversion device, and a sensor signal conversion method for a keyboard instrument.
The second object of the present invention is to provide a keyboard instrument sensor data conversion device, a sensor data conversion method, a sensor signal conversion device, and a sensor signal conversion method capable of coping with changes over time and changes over time. is there.
[0006]
[Means for Solving the Problems]
In order to solve the above problem, the configuration according to claim 1 is a sensor data corresponding to an output signal of a sensor for detecting an operation state of a key or pedal of a keyboard instrument. Sensor data whose data bits are a certain bit length A sensor data conversion device for a keyboard instrument that generates conversion sensor data by performing conversion on the basis of a signal level range of a detection signal of the sensor output in an operating state of the key or the pedal. Data data The bit is less than the bit length of the data bits of the sensor data Predetermined number of bits Use data bits It is characterized by having data conversion means for performing data conversion.
[0007]
According to a second aspect of the present invention, in the configuration of the first aspect, the data conversion means sets the sensor data at a predetermined position of the key or the pedal as X, and sets the number of bits of the converted sensor data to B1. When the number of bits of the sensor data is B2 (B2 = B1 + n; n is a natural number), the sensor data X is
2 ^{(Z + B1)} ≦ X <2 ^{(Z + B1 + 1)} (However, Z is an integer satisfying 0 ≦ Z <n)
When satisfying the above, among the data bits of the sensor data, the data bits of the (Z + 1) th bit to the (B1 + Z) th bit are the 0th bit to the (B1-1) th bit of the converted sensor data. A bit shift means for performing bit shift processing is provided.
[0008]
The configuration according to claim 3 is the configuration according to claim 1, wherein the data conversion means sets the sensor data at a predetermined position of the key or the pedal to X, sets the number of bits of the converted sensor data to B1, and When the number of bits of sensor data is B2 (B2 = B1 + n; n is a natural number of 2 or more), the sensor data X is
2 ^{(Z + B1)} ≦ X <2 ^{(Z + B1 + 1)} (However, Z is an integer satisfying −1 ≦ Z <n)
When satisfying the above, among the data bits of the sensor data, the data bits of the (Z + 1) th bit to the (B1 + Z) th bit are the 0th bit to the (B1-1) th bit of the converted sensor data. A bit shift means for performing bit shift processing is provided.
[0009]
According to a fourth aspect of the present invention, in the configuration of the second or third aspect, the bit shift unit stores rank data corresponding to the value of Z for each key or each pedal. And shift control means for reading the rank data when one of the keys or one of the pedals is operated, and controlling the bit shift amount in the bit shift processing.
[0010]
According to a fifth aspect of the present invention, in the configuration according to any of the second to fourth aspects, the predetermined position is a rest position.
[0011]
According to the sixth aspect of the present invention, there is provided sensor data corresponding to an output signal of a sensor for detecting an operation state of a key or pedal of a keyboard instrument. Sensor data whose data bits are a certain bit length A sensor data conversion method for a keyboard instrument that generates conversion sensor data by performing conversion on the basis of a signal level range of a detection signal of the sensor that is output in an operating state of the key or the pedal. Data data The bit is less than the bit length of the data bits of the sensor data Predetermined number of bits Use data bits A data conversion process for performing data conversion is provided.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
[1] Embodiment
[1.1] Overall configuration of the embodiment
FIG. 1 shows a schematic configuration diagram of a main part of the automatic piano according to the embodiment.
The automatic piano includes an action mechanism 3 that transmits the movement of the key 1 to the hammer 2, a string 4 that is struck by the hammer 2, a solenoid 5 that drives the key 1, and a damper 6 that stops vibration of the string 4. , And is configured.
In addition, the automatic piano generates key trajectory data based on performance data supplied from a recording medium or a real-time communication device, and uses the trajectory data to generate a key original velocity instruction value (t, Vr) before reproduction. Based on the processing unit 10, the supplied original speed instruction value (t, Vr), the motion controller 11 that generates and outputs the speed instruction value Vr corresponding to the position of the key 1 at each time, and the speed instruction value Vr A servo controller 12 that supplies a corresponding exciting current to the solenoid 5 and compares the output speed Vy as a feedback signal supplied from the solenoid 5 with the speed instruction value Vr and performs servo control so that both coincide with each other. It is prepared for.
[0013]
Furthermore, the automatic piano measures the stringing speed, a sensor box 25 constituting a key sensor, a plate-like shutter 26 constituting the key sensor and attached to the lower surface of the key 1, a hammer shutter 27 attached to the action mechanism 3, and the like. The speed of the hammer 2, that is, the string striking speed (sounding speed) is measured by measuring the movement speed of the hammer shutter 27 based on the sensor SE and the output signal of the sensor SE. And a performance recording unit 30 that detects the passage start time as a string striking time (sounding time) through the sensor SE.
[0014]
[1.2] Control system
FIG. 2 shows a schematic block diagram of the control system of the present embodiment.
The control system is provided with a CPU 201 that controls the entire control system, a ROM 202 that stores control programs, control data, and the like, a RAM 203 that temporarily stores various data, and various control switches. A panel switch unit 204, an actuator drive circuit 208 for driving an unillustrated actuator and setting the mute performance mode in which the hammer 2 does not contact the string 4, a key number (= key code) supplied from the CPU 201, and a velocity (key press) Sound source circuit 210 that generates a musical sound signal based on performance control data such as a key-on signal and a key-off signal and supplies the musical sound signal to the speaker SP or the headphone HH.
[0015]
Further, the control system includes an LED driver 220 for driving the LED 224 that emits detection light, and a light emission side on which the detection light emitted from the LED 224 is input via an optical fiber and is emitted to a light receiving side sensor head 222 described later. A sensor head 221; a light receiving side sensor head 222 that receives detection light and outputs it via an optical fiber; and a photodiode 225 that performs photoelectric conversion of the detection signal output from the light receiving side sensor head 222 and outputs it as a detection signal. The A / D conversion circuit 223 that performs A / D conversion of the detection signal and outputs it as detection data, the flexible disk driver 250 that writes / reads performance information to / from the flexible disk 251, and the RAM 203 temporarily. Based on the stored performance information, a solenoid drive signal is generated and the solenoid 5 By driving the Renoidopin 5P it is configured to include the servo controller 12 for performing an automatic performance by driving the hammer 2, the.
In this case, the light emitting side sensor head 221, the light receiving side sensor head 222, the LED 224, the photodiode 225, and the shutter 26 constitute a key sensor.
[0016]
[1.3]
FIG. 3 is a schematic configuration diagram showing the configuration of the key sensor of this embodiment.
In FIG. 3, detection light is supplied from an LED 224 via an optical fiber, and a light emission side sensor head 221 that emits detection light having a diameter of about 5 mm to detect the position of the shutter 26, and a light emission side sensor head 221. And a light receiving side sensor head 222 that receives the detection light emitted from the light source and sends it to the photodiode 225 via an optical fiber.
Detection light is sent to the photodiode 225 by the light receiving side sensor head 222 and converted into an output signal Sa corresponding to the amount of light by the photodiode 225.
In this case, the detection light emitted from the light emission side sensor head 221 is shielded according to the insertion state of the shutter 26 in the detection light optical path, and the light reception amount of the light reception side sensor head 222 is the position of the shutter 26, that is, , And changes depending on the position of the key 1.
[0017]
Therefore, the output signal Sa of the photodiode 225 is a signal having an analog amount corresponding to the position of the key 1.
For example, the change in the output signal Sa is between the position (= end position) in the state where the key 1 is pressed to the position where the key 1 is pressed from the position where the key 1 is not pressed (= rest position). As shown in FIG. 4, it is expressed in a substantially linear state.
Between the rest position and the end position, a first reference position K1 to a fourth reference position K4, which will be described later, corresponding to a detection position for referring to the output signal of the sensor are set.
[0018]
[1.4] Operation of the embodiment
[1.4.1] Processing routine
First, various processing routines for performing the operation of the embodiment will be described.
FIG. 5 is a timing chart showing the relationship between the processing routines.
The processing routine of this embodiment is roughly classified into a main routine, an A / D interrupt routine, and a timer interrupt routine.
The main routine is a routine for performing main processing in sound generation control, and most of the processing is performed by this main routine.
The A / D interrupt routine performs processing for reading the output signal of the photodiode 225 in units of four keys. This A / D interrupt routine is set to be started approximately every 40 [μsec] in the present embodiment.
The timer interrupt routine performs a timer update process for updating a timer value used for time measurement, a process for subtracting a count value, and the like. This timer interrupt routine is set to be started every 100 [μsec] in this embodiment.
In this case, when the A / D interrupt routine and the timer interrupt routine compete with each other, the timer interrupt routine is activated with priority. This is because if the timer interrupt routine is not started at a constant period, an error occurs in the timer value and other controls are disturbed.
Note that FIG. 5 schematically shows the operation timing of each processing routine, and does not accurately represent the ratio of the actual processing time.
[0019]
[1.4.2] A / D interrupt processing
Here, the A / D interrupt process will be described with reference to FIG. In this case, the output data bit length of the A / D converter 223 is 10 bits, and the processing data bit length in the CPU 201 is 8 bits.
The A / D converter 223 operates in parallel with the CPU 201, and generates an A / D interrupt request when the A / D conversion of the output signals of the key sensors corresponding to the four keys is completed. In this case, the four keys are always handled as one set (one channel), and channel numbers 0 to 23 (in the case of 88 keys) are assigned to each channel.
As a result, the CPU 201 starts A / D interrupt processing corresponding to the A / D interrupt processing routine.
[0020]
First, when an A / D interrupt request is input, the CPU 201 outputs an A / D stop request for stopping the A / D conversion process to the A / D converter 223, and in parallel therewith. The LED 224 of the key sensor corresponding to the four keys of the next channel is turned on (step S1).
Subsequently, the CPU 201 refers to the rank data in the key-rank table stored in advance in the RAM 203 corresponding to the four key numbers corresponding to the channel that has output the A / D stop request. The rank data calculation method will be described in detail later.
Based on the rank data of each key of the CPU 201, it is determined which of the data bits (10 bits in the above example) constituting the output data of the A / D converter 223 is used for processing. .
More specifically, it is assumed that a key-rank table is stored as shown in FIG.
[0021]
In this case, when processing output data corresponding to the 85th key, the 86th key, the 87th key, and the 88th key among all 88 keys constituting the automatic piano, the CPU 201 determines the 85th key. Since rank data = 2, as shown in FIG. 8C, among the output data of the A / D converter 223, the 2nd to 9th bits are treated as 8 processed data bits. decide.
Since the rank data = 0 for the 86th key, the CPU 201 converts the 0th to 7th bits of the output data of the AD converter 223 to 8 bits as shown in FIG. Decide to treat as processing data bits.
Furthermore, since the rank data = 1 for the 87th key, the CPU 201 converts the first bit to the eighth bit of the output data of the AD converter 223 to 8 bits as shown in FIG. Decide to treat as processing data bits.
Similarly, since the rank data = 1 for the 88th key as well, the CPU 201 outputs the first bit to the eighth bit in the output data of the A / D converter 223 as shown in FIG. 8B. Are treated as 8-bit processed data bits.
[0022]
Then, the CPU 201 stores a part of the output data of the A / D converter 223 determined as the processing data bits together with a timer value (= corresponding to the detection time of each channel) corresponding to the normal A / D conversion result data. And written in a predetermined area of the RAM 203 (step S2).
Next, the CPU 201 increments the detection target channel number by 1 (however, if the channel number = 23, the channel number = 0 is reset), and the A / D conversion process in the A / D converter 223 is restarted. Accordingly, an A / D start request is output to the A / D converter 223 (step S3), and the A / D interrupt process is terminated.
[0023]
[1.4.3] Main processing
Next, the main process of this embodiment will be described.
FIG. 9 shows a flowchart showing the processing contents of the main routine.
First, when the power is turned on, the CPU 201 performs initialization processing for initializing registers and RAM and setting interrupts (step S11).
Then, the output data of the A / D converter 223 at the rest position of each key (for example, in the case of an 88-key automatic piano, the first key to the 88th key) is acquired.
When the value of the output data of the A / D converter 223 corresponding to each key is X,
X <256 (= 2 ⁸ )
In this case, rank data is set to 0 and written to the area corresponding to the key in the key-rank table of the RAM 203, and 8 bits from the 0th bit to the 7th bit are output from the output data of the AD converter 223. The processing target output data of the AD converter 223 is calculated, the reference position data K1 to K4 are calculated based on the processing target output data, and the obtained processing target output data and the reference position data K1 to K4 are stored in the RAM 203 (step S12).
[0024]
Similarly,
256 ≦ X <512 (= 2 ⁹ )
In this case, the rank data is set to 1 and written in the area corresponding to the key in the key-rank table of the RAM 203, and 8 bits from the first bit to the eighth bit are output from the output data of the AD converter 223. The processing target output data of the AD converter 223 is calculated, the reference position data K1 to K4 are calculated based on the processing target output data, and the obtained processing target output data and the reference position data K1 to K4 are stored in the RAM 203 (step S12).
[0025]
Similarly,
512 ≦ X
In this case, rank data = 2 is written in the area corresponding to the key in the key-rank table of the RAM 203, and 8 bits from the second bit to the ninth bit are output from the output data of the AD converter 223. The processing target output data of the AD converter 223 is calculated, the reference position data K1 to K4 are calculated based on the processing target output data, and the obtained processing target output data and the reference position data K1 to K4 are stored in the RAM 203 (step S12).
When the storage of the processing target output data and the reference position data K1 to K4 at the rest position of all the keys (all 88 keys in the above example) is finished, the number of the processing target key (key) (the initial value is 87). 1 (corresponding to the 88th key) is added to the value of the processing target key register (however, it is set to 0 when the key number = 87) (step S13).
Next, the A / D conversion result data acquired in the A / D interrupt processing for the key corresponding to the value of the processing target key register and written in a predetermined area of the RAM 203 and the corresponding timer value (= at the detection time of each channel) Equivalent) is read (step S14).
[0026]
Next, the CPU 201 acquires a key state stored in the RAM 203 in advance from the RAM 203 (step S15).
Here, the state of the key will be described.
The key state includes an UPPER state when the key is between the rest position and the reference position K1 (see FIG. 4), and a TOUCH-A state where the key exceeds the reference position K1 and does not reach the reference position K2. The COUNT-DOWN-0 state where the key exceeds the reference position K2 and does not reach the reference position K3, the COUNT-DOWN-1 state where the key exceeds the reference position K3 and does not reach the reference position K4, the key COUNT-DOWN-2 state in which the position exceeds the reference position K4, COUNT-DOWN-3 state in which a plurality of reference positions are passed in the key position sampling interval with a fast key pressing speed, and a sound is made The SOUND state, the key in the key release state, the HOLD state in which the key has passed the reference position K2, and the key in the HOLD state will not return to the rest position. , There is a TIME-OVER state is a state of maintaining again depressed by the reference position is a state beyond the K2 TOUCH-B state and TOUCH-B state became key preset predetermined time or more that state.
[0027]
Next, the CPU 201 determines whether or not the key state is the UPPER state (step S16). If the key state is the UPPER state (step S16; Yes), the sound generation control process corresponding to the UPPER state is performed. After executing the routine and rewriting the key state of the RAM 203 to the UPPER state (step S22), the process proceeds to step S13 again.
If it is determined in step S16 that the key is not in the UPPER state (step S16; No), the COUNT-DOWN-0 state, the COUNT-DOWN-1 state, the COUNT-DOWN-2 state, or the COUNT-DOWN-3. It is determined whether it is in one of the states (step S17), and the key state is any of the COUNT-DOWN-0 state, the COUNT-DOWN-1 state, the COUNT-DOWN-2 state, or the COUNT-DOWN-3 state. If it is (step S17; Yes), the sound generation control processing routine corresponding to the COUNT-DOWN-0 state, the COUNT-DOWN-1 state, the COUNT-DOWN-2 state, and the COUNT-DOWN-3 state is executed. , RAM 203 key status is COUNT-DOWN-0 , COUNT-DOWN-1 state, COUNT-DOWN-2 state or of COUNT-DOWN-3 state, after rewriting the corresponding state (step S23), the control goes back to the step S13 processing.
[0028]
If it is determined in step S17 that the key is not in the COUNT-DOWN-0 state, the COUNT-DOWN-1 state, the COUNT-DOWN-2 state, or the COUNT-DOWN-3 state (step S17; No) Then, it is determined whether or not the key state is the TOUCH-A state (step S18). If the key state is the TOUCH-A state (step S18; Yes), the sound corresponding to the TOUCH-A state is generated. After executing the control process routine (step S24), the process proceeds to step S13 again.
If it is determined in step S18 that the key state is not the TOUCH-A state (step S18; No), it is determined whether or not the key state is the SOUND state (step S19), and the key state is SOUND. If it is in the state (step S19; Yes), the sound generation control processing routine corresponding to the SOUND state is executed, the key state in the RAM 203 is rewritten to the SOUND state (step S25), and then the process returns to step S13. .
If it is determined in step S19 that the key state is not the SOUND state (step S19; No), it is determined whether or not the key state is the HOLD state (step S20), and the key state is in the HOLD state. If there is any (step S20; Yes), the sound generation control processing routine corresponding to the HOLD state is executed, the key state of the RAM 203 is rewritten to the HOLD state (step S26), and the process returns to step S13.
[0029]
If it is determined in step S20 that the key state is not the HOLD state (step S20; No), it is determined whether or not the key state is the TIME-OVER state (step S21), and the key state is TIME. If the state is the -OVER state (step S21; Yes), the sound generation control processing routine corresponding to the TIME-OVER state is executed, and after the key state of the RAM 203 is rewritten to the TIME-OVER state (step S27), the process is performed. The process proceeds to step S13 again.
If it is determined in step S21 that the key is not in the TIME-OVER state (step S21; No), it is considered that the key is in the TOUCH-B state, so the tone generation control processing routine corresponding to the TOUCH-B state is executed. Then, after the key state of the RAM 203 is rewritten to the TOUCH-B state (step S28), the process proceeds to step S13 again.
[1.5] Effects of the embodiment
As described above, according to the present embodiment, an appropriate dynamic range can be obtained based on the output data of the A / D converter without increasing the number of processing bits and the storage capacity of the processing system (CPU, RAM, etc.). Can be obtained, and measurement with high accuracy can be performed.
Furthermore, since the processing of the output data of the A / D converter can be dynamically changed, only the output bit length is lengthened, and the bit area (numbered bit from the first bit) to be used in the output bit for each key. Unlike the method in which the number of bits) is selected when the automatic piano is manufactured and the bit length of the processing target data is fixed, it is possible to easily cope with aging and secular change.
[0030]
[2] Modification of embodiment
[2.1] First modification
In the above description, the case where the output bit length of the A / D converter is 10 bits has been described, but more generally, sensor data that is output data of the A / D converter at a predetermined position is set to X When the number of bits of converted sensor data that can be processed by the CPU is B1, and the number of bits of sensor data is B2 (B2 = B1 + n; n is a natural number), the sensor data X is
2 ^{(Z + B1)} ≦ X <2 ^{(Z + B1 + 1)} (However, Z is an integer satisfying 0 ≦ Z <n)
Of the sensor data, the (Z + 1) -th to (B1 + Z) -th bit of the sensor data is used as the 0-th to (B1-1) -th bit of the converted sensor data. What is necessary is just to comprise so that a process may be performed.
[0031]
[2.2] Second modification
In the above description, the case where the output bit length of the A / D converter is 10 bits has been described. However, as in the first modification, sensor data that is output data of the A / D converter at a predetermined position is determined. Is X, the number of bits of converted sensor data that can be processed by the CPU is B1, and the number of bits of sensor data is B2 (B2 = B1 + n; n is a natural number of 2 or more). ,
2 ^{(Z + B1)} ≦ X <2 ^{(Z + B1 + 1)} (However, Z is an integer satisfying 1 ≦ Z <n)
Of the sensor data, the (Z + 1) -th to (B1 + Z) -th bit of the sensor data is used as the 0-th to (B1-1) -th bit of the converted sensor data. It is also possible to configure to perform processing.
[0032]
[2.3] Third modification
In the above description, the data bit position to be used is shifted among the data bits constituting the output data of the A / D converter according to the rank. For example, when rank data = 0 The same effect can be obtained by shifting 2 bits to the upper bit side and shifting 1 bit to the upper bit side when rank data = 1 and always using the second to ninth bits on the CPU side. can get.
Similarly, when rank data = 0, 1 bit is shifted to the upper bit side, and when rank data = 2, 1 bit is shifted to the lower bit side, and the first to eighth bits are always shifted to the CPU side. You may make it use in.
[0033]
[2.4] Fourth modification
In the above description, only the sensor data conversion process in the case of a key has been described, but the present invention can be similarly applied to a pedal.
[2.5] Fifth modification
In the above description, the rank data is set with the predetermined position as the rest position. However, the rank data may be set in real time for each A / D interrupt process.
[2.6] Sixth Modification
In the above description, rank data is set at the time of actual operation. However, rank data can be fixedly determined in advance if a sensor with little change with time and a small individual difference can be used.
[2.7] Seventh Modification
Although the automatic piano has been described in the above description, the present invention can be applied to other keyboard instruments.
[0034]
【The invention's effect】
According to the present invention, based on the signal level range of the detection signal of the sensor output in the operating state of the key or the pedal, the data conversion is performed so that the data range of the conversion sensor data becomes a predetermined data range. Alternatively, the conversion sensor signal is detected by detecting the signal level range of the detection signal of the sensor and amplifying the detection signal by changing the amplification factor so that the signal level range of the conversion sensor signal becomes a predetermined signal level range. Therefore, sensor data or sensor output signal having an appropriate dynamic range for the bit length used in the processing system can be obtained without increasing the storage capacity of the subsequent data processing system. Become.
In addition, since the data conversion method or the gain can be changed dynamically, it is possible to easily cope with changes over time and changes over time.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a main part of an automatic piano according to an embodiment.
FIG. 2 is a block diagram illustrating a schematic configuration of a control system of the automatic piano according to the embodiment.
FIG. 3 is a diagram illustrating a configuration of a key sensor.
FIG. 4 is an explanatory diagram of a relationship between a key stroke and a reference position.
FIG. 5 is a timing chart of each process according to the embodiment.
FIG. 6 is a processing flowchart of A / D interrupt processing.
FIG. 7 is an explanatory diagram of a storage state of rank data.
FIG. 8 is a diagram for explaining a relationship between rank data and actually used data bits;
FIG. 9 is a process flowchart of a main routine.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Key, 2 ... Hammer, 3 ... Action mechanism (hammer action), 4 ... String, 5 ... Solenoid, 5P ... Solenoid pin, 6 ... Damper (sound stop mechanism), 10 ... Reproduction pre-processing part, 11 ... Motion controller , 12 ... Servo controller, 25 ... Sensor box, 26 ... Shutter, 27 ... Hammer shutter, 30 ... Performance recording unit, 31 ... Post-recording processing unit, 201 ... CPU, 202 ... RAM, 203 ... ROM, 204 ... Panel switch unit 208 ... Actuator drive circuit, 210 ... Sound source circuit, 220 ... LED driver, 221 ... Light emitting side sensor head, 222 ... Light receiving side sensor head, 223 ... A / D conversion circuit, 224 ... LED, 225 ... Photodiode, 250 ... Flexible disk driver, 251... Flexible disk.

Claims (6)

A sensor of a keyboard instrument that generates sensor data corresponding to a sensor data corresponding to an output signal of a sensor that detects an operation state of a key or pedal of a keyboard instrument, and converts the sensor data having a data bit length. A data converter,
Based on the signal level range of the detection signal of the sensor output in the operation state of the key or the pedal, the data bit of the conversion sensor data is predetermined to be less than the bit length of the data bits of the sensor data. A sensor data conversion device for a keyboard instrument, comprising data conversion means for performing data conversion using data bits having a predetermined number of bits . The sensor data conversion device for a keyboard instrument according to claim 1, wherein the data conversion means sets the sensor data at a predetermined position of the key or the pedal as X, and sets the number of bits of the conversion sensor data as B1. When the number of bits of the sensor data is B2 (B2 = B1 + n; n is a natural number), the sensor data X is
2 ^{(Z + B1)} ≦ X <2 ^{(Z + B1 + 1)} (where Z is an integer satisfying 0 ≦ Z <n)
When satisfying the above, among the data bits of the sensor data, the data bits of the (Z + 1) th bit to the (B1 + Z) th bit are the 0th bit to the (B1-1) th bit of the converted sensor data. A keyboard instrument sensor data conversion device comprising bit shift means for performing bit shift processing. 2. The sensor data conversion device for a keyboard instrument according to claim 1, wherein the data conversion means sets the sensor data at a predetermined position of the key or the pedal to X, sets the number of bits of the converted sensor data to B1, and sets the sensor data. When the number of bits of B2 is B2 (B2 = B1 + n; n is a natural number of 2 or more), the sensor data X is
2 ^{(Z + B1)} ≦ X <2 ^{(Z + B1 + 1)} (where Z is an integer satisfying 1 ≦ Z <n)
When satisfying the above, among the data bits of the sensor data, the data bits of the (Z + 1) th bit to the (B1 + Z) th bit are the 0th bit to the (B1-1) th bit of the converted sensor data. A keyboard instrument sensor data conversion device comprising bit shift means for performing bit shift processing. The sensor data conversion device for a keyboard instrument according to claim 2 or claim 3,
The bit shift means; rank data storage means for storing rank data corresponding to the value of Z for each key or each pedal;
Shift control means for reading out the rank data at the time of operation of any one of the keys or any one of the pedals, and controlling a bit shift amount in the bit shift processing;
A sensor data conversion device for a keyboard instrument, comprising: In the keyboard musical instrument sensor data conversion device according to any one of claims 2 to 4,
A sensor data conversion device for a keyboard instrument, wherein the predetermined position is a rest position. A sensor of a keyboard instrument that generates sensor data corresponding to a sensor data corresponding to an output signal of a sensor that detects an operation state of a key or pedal of a keyboard instrument, and converts the sensor data having a data bit length. A data conversion method,
Based on the signal level range of the detection signal of the sensor output in the operation state of the key or the pedal, the data bit of the conversion sensor data is predetermined to be less than the bit length of the data bits of the sensor data. A method for converting sensor data of a keyboard instrument, comprising: a data conversion step for performing data conversion using data bits having a predetermined number of bits .

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