JPH10232671A - Automatic piano - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reproduce the actions of keys with good accuracy by canceling the load fluctuation by pedals (dampers) while decreasing a memory capacity. SOLUTION: When the position information detected by a pedal (damper) position sensor 24 is supplied to a driving parameter correcting section 25, the driving parameter correcting section 25 forms correction data HD by referencing the position information. A driving parameter changing direction 26 forms corrected position data KD' by adding the correction data HD to the position data KD of the key. As a result, the target value as a driving parameter is corrected. A key driving section 27 drives a key solenoid 28 in such a manner that the corrected position data KD' and the position data of the key from a key solenoid position sensor 29 coincide. As a result, the actions of the keys are reproduced while the load fluctuation of the pedals (dampers) are canceled.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic piano suitable for reproducing performance information performed using a loud petal.

[0002]

2. Description of the Related Art In an automatic piano, when a player presses a key, an action mechanism operates in conjunction with the key, and the damper moves away from the string and the hammer rotates to strike the string. Also, when the key is released, the damper comes into contact with the strings and the sound is muted. In this way, the musical tone is depressed → string strike → key release →
It is usually generated by a series of operations called silence. Therefore, at the time of recording, performance information is generated and recorded based on each of the above operations, and at the time of reproduction, the operation of the key is controlled based on the read performance information. In the control of the key in this case, the key is driven by exciting the solenoid based on the performance information, and the hammer is rotated and the string is struck accordingly.

Some automatic pianos include a loud pedal. The loud pedal is interlocked with the damper via a piano mechanism, and when the player depresses the loud pedal, the damper is simultaneously moved away from the strings in response to this. As a result, even after the key is completely released, the sound can be resonated without being silenced. Also,
The timing of pressing the loud pedal should be before or after the sound,
Or, depending on whether they are done at the same time, the way the sound resonates differs.
Therefore, musicians often use loud pedals to express their interpretation of the work. For this reason, some automatic pianos record not only information on the key operation but also information on the loud pedal as performance information, and reproduce the information to reproduce the actual performance.

In an automatic piano reproduction system, position data indicating a key position is calculated for each unit time based on performance information, and the position of the key is controlled using the position data as a target value. Will be As a key control method, the key position is detected by a sensor, the key position is compared with a target value,
In many cases, a feedback control method for performing control so that the two coincide with each other is performed.

[0005] Incidentally, since the key is linked to the action mechanism, the action mechanism acts as a load on the key. Further, since the loud pedal is interlocked with the damper which is a part of the action mechanism, the load on the key varies depending on the degree of depression of the loud pedal. Therefore, when the key is controlled during reproduction, the load fluctuation due to the loud pedal acts as a disturbance. In this case, in the feedback control, the effect of disturbance can be reduced by increasing the servo gain. But,
Increasing the servo gain has the disadvantage that the phase margin decreases and the servo system becomes unstable. Therefore, the servo gain is determined based on a balance between suppression of disturbance and stability of the servo system. For this reason, the servo gain could not be made sufficiently high so that the position of the key would not fluctuate due to the load fluctuation of the loud pedal.

In order to improve this point, in a conventional automatic piano, when generating drive data for driving a solenoid, a drive data table is referred to. Two types of drive data tables are prepared, one corresponding to the state in which the loud pedal is depressed and the other in the original state. When a drive command value is input, the table is selected according to the state of the loud pedal, and the corrected drive data is output. It is supposed to be.

[0007]

By the way, the state of the loud pedal in the actual performance includes not only the fully depressed state and the original state but also an intermediate state, and the load applied to the key varies depending on the degree of depression. Therefore, if only two types of driving data tables are provided, there is a problem that the key operation cannot be accurately reproduced by canceling the load in the intermediate state.

In this case, if the number of driving data tables is increased to cope with an intermediate state, the memory capacity increases. For example, if the depression state of the loud pedal is represented by 7 bits, 128 drive data tables are required.
On the other hand, if the intermediate state is calculated by interpolation processing to reduce the memory capacity, a special operation means is required for the interpolation processing, and furthermore, an error occurs and the key cannot be driven accurately. There is.

The present invention has been made in view of the above circumstances, and has as its object to reduce the memory capacity and cancel the load fluctuation caused by the loud pedal to accurately reproduce the key operation.

[0010]

According to a first aspect of the present invention, there is provided an automatic piano for performing an automatic performance based on performance information indicating a key state and a loud pedal state. In, data generation means for generating the position data of the key based on performance information indicating the state of the key, and servo-driven the key so that the position of the key is the position indicated by the position data, Driving means for setting the characteristics of the servo system using the driving parameters;
State detecting means for detecting the state of the loud pedal, storage means for storing correction data for correcting the drive parameter in association with the state of the loud pedal, and the storage means based on a detection result of the state detecting means. Correction means for reading out the correction data and correcting the drive parameters based on the correction data.

Further, in the invention according to claim 2,
A data generating means for generating position data of the key based on performance information indicating a key state, in an automatic piano performing automatic performance based on performance information indicating a key state and a loud pedal state; Driving means for servo-driving the key so that the position of the key becomes the position indicated by the position data, and setting the characteristics of the servo system using driving parameters; and correcting data for correcting the driving parameters to the state of the loud pedal. Storage means for associating and storing the correction data, and correction means for reading the correction data from the storage means based on performance information indicating the state of the loud pedal, and correcting the drive parameter based on the correction data. Features.

Further, in the invention according to claim 3,
The state detecting means detects the position of the loud pedal, and the storage means stores the correction data in association with the position of the loud pedal.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION

1. Hereinafter, a configuration of an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of an automatic piano according to an embodiment of the present invention. In FIG. 1, 1 is a key, and 3 is a hammer action mechanism for transmitting the movement of the key 1 to the hammer 2. 4 is a string struck by the hammer 2, 28 is a key solenoid for driving the key 1, and the position of the plunger is detected by a key solenoid position sensor 29 formed integrally therewith. I have.
In this case, when the plunger of the key solenoid 28 protrudes, the key 1 rotates around the balance pin P and descends toward the player (hereinafter, this state is referred to as a key pressed state). The action mechanism 3 operates, the damper 6 separates from the string 4, and the hammer 2 rotates and strikes the string. On the other hand, when the player plays, by pressing the key 1 with a finger, the same operation as described above occurs, and the string is struck. A damper mechanism 100 transmits the movement of the loud pedal 101 to the damper 6. In this case, when the player depresses the loud pedal 101, the damper 6 is pushed upward, and the damper 6 separates from the string 4. On the other hand, the player releases his / her foot from the loud pedal 101 and
When the step 1 returns from the depressed state to the original state, the damper 6 comes into contact with the string 4 as shown.

In the figure, SE1 and SE2 are sensors for measuring the string striking speed.
Measures the speed of the hammer 2, that is, the stringing speed (sounding speed), by measuring the time that the hammer 2 passes between these sensors SE1 and SE2.
The time when the string passes the sensor SE1 is the stringing time (the sounding time)
Detected as

Reference numeral 7 denotes a plate-shaped shutter attached to the lower surface of the key 1. Reference numeral 8 denotes a key sensor composed of two pairs of photosensors SF2 and SF3 provided at a predetermined distance in the vertical direction. When the key 1 starts being pressed, the upper photosensor SF2 is first shielded from light, and then Of the photo sensor SF3 is shielded from light. At the time of key release, the lower photo sensor SF3 enters a light receiving state, and then the upper photo sensor SF2 enters a light receiving state.

The output signal of the key sensor 8 is transmitted to the performance recording section 3.
0 is supplied. When the key is pressed, the performance recording unit 30
Measures the time from when the upper photo sensor SF2 enters the light-shielded state until the lower photo sensor SF3 enters the light-shielded state, and detects the key-depression speed. Further, the performance recording unit 30 detects the time at which the lower photo sensor SF2 enters the light blocking state as the key pressing time.

On the other hand, at the time of key release, the performance recording unit 30
Measures the time from when the lower photo sensor SF3 enters the light receiving state to when the upper photo sensor SF2 enters the light receiving state, and detects the key release speed therefrom. The performance recording unit 30 detects the time at which the upper photo sensor SF2 enters the light receiving state as the key release time.

A loud pedal solenoid 23 drives the loud pedal 101 during reproduction. Also 2
Reference numeral 4 denotes a loud pedal position sensor.
01 is detected. The output signal of the loud pedal position sensor 24 is supplied to the performance recording unit 30.

The recording post-processing section 31 performs normalization processing on various information supplied from the performance recording section 30 to convert the information into a predetermined data format, and then supplies the converted information to an external recording medium as performance information. . Here, the normalization process is a process for absorbing individual differences between pianos. That is,
Loud pedal position, string striking time / string striking speed, key depressing time / key depressing speed, key releasing time / key releasing speed, etc. are unique to each piano due to sensor position, structural difference, or mechanical error. Therefore, this is a process for assuming a standard piano and converting it into a string striking time, a string striking speed, and the like in the piano.

Numeral 20 denotes a reproduction system, and based on performance data ED supplied from a recording medium or an external real-time communication device, the key position data KD (t, X) and the loud pedal 101 for each unit time t are determined. Position data R
D (t, X) is created, and the key 1 and the loud pedal 101 are driven based on these.

2. Reproduction System FIG. 2 is a block diagram of a reproduction system of the automatic piano according to the present embodiment. FIG. 2 also shows the peripheral circuit in addition to the reproduction system 20. In the figure, a control unit 21 generates key trajectory data based on performance data ED, and obtains key position data KD from key trajectory data.
Create (t, X). In addition, the control unit 21 outputs the position data RD of the loud pedal 101 based on the performance data ED.
Create (t, X).

Reference numeral 22 denotes a loud pedal drive section, which generates a drive current for driving the loud pedal solenoid 23 based on the position data RD (t, X) of the loud pedal 101. When the drive current is supplied to the loud pedal solenoid 23, the solenoid coil is excited and the loud pedal 10
1 is driven. The position of the loud pedal 101 is detected by the loud pedal position sensor 24. This detection signal is supplied to the loud pedal drive unit 22 as a feedback signal. The loud pedal drive unit 22 receives the position data RD
And the feedback signal are compared, and the loud pedal solenoid 23 is driven so that the two coincide.

Reference numeral 25 denotes a drive parameter correction unit, which comprises a correction table or the like in which correction data HD is stored in association with a loud pedal position. The drive parameter correction unit 25 predicts a change in the damper load applied to the key 1 based on the output signal of the loud pedal position sensor 24, and generates correction data HD for canceling the change. The drive data, which is a parameter for controlling the key 1, is corrected by the correction data HD.

The drive parameters include key position data KD as a target value, servo gain, and fixed force data for giving an offset. In this example, the key position data KD (target value) is corrected. It is targeted.
The value of the correction data HD is a value measured by experiment so that when added to the target value, the fluctuation of the damper load is canceled and an accurate stringing result is obtained.

In this case, the correction table is constituted by a memory, in which correction data HD is stored in association with the position of the loud pedal 101. Therefore, the correction data HD can be stored not only in the state in which the loud pedal 101 is depressed and in the original state, but also in an intermediate state between them. The correction data HD is data for correcting a drive parameter, and does not indicate a drive command value itself. Therefore, according to this example, there is no need to prepare a drive data table according to the position of the loud pedal 101, so that the memory capacity can be significantly reduced.

Next, reference numeral 26 denotes a drive parameter changing unit for changing the drive parameters based on the correction data HD. Specifically, the correction data HD is added to the position data KD to generate corrected position data KD '. The corrected position data KD 'takes into account the load fluctuation of the damper.

Next, reference numeral 27 denotes a key drive unit, which generates a drive current based on the corrected position data KD '. When the key solenoid 28 is driven by this drive current, the position of the key is detected by the key solenoid position sensor 29,
This is fed back to the key drive unit 27 as a feedback signal.

3. Key Drive Unit Next, the key drive unit 27 will be described. FIG. 3 is a circuit diagram of the key driving unit 27. In the figure, the subtractor 271 has the corrected position data K
D ′ is supplied to the positive input terminal as a target value,
The actual position data JD of the key 1 is supplied from the key solenoid position sensor 29. The adder 271 subtracts the actually measured position data JD from the corrected position data KD ′ to generate error data.

Thereafter, when the error data is supplied to the amplifier 272, the amplifier 272 amplifies and outputs the error data. The servo gain is determined by this degree of amplification. In this example, since the feedback control is performed using the corrected position data KD 'in consideration of the load fluctuation of the damper as the target value, it is not necessary to set the servo gain too high, and the servo system can be stabilized.

When the output data of the amplifier 272 is supplied to one input terminal of the adder 273, the adder 27
Numeral 3 adds the fixed force data supplied to the other input terminal and the output data to generate drive data. And
The drive data is converted into a drive current via a drive current generation circuit (not shown), and the drive current
Is driven.

4. Conclusion According to the above-described embodiment, the correction data HD corresponding to the position of the loud pedal 101 is previously stored in the drive parameter correction unit 2.
5 is stored in a correction table provided in the loud pedal 1 detected by the loud pedal position sensor 24.
The correction data HD was generated based on the position of No. 01, and the target value as the drive parameter was corrected using this. Therefore, the key 1 depends on how much the loud pedal 101 is depressed.
It is possible to predict the fluctuation of the load of the damper added to the above and cancel the fluctuation, so that the operation of the key 1 can be accurately reproduced. As a result, the musician turns the loud pedal 101
When expressing subtle nuances of music using
You can reproduce the actual performance.

According to the above-described embodiment, since the correction data table may store the correction data HD for correcting the drive parameters in association with the state of the loud pedal 101, the memory capacity is greatly increased. Can be reduced.

Further, since the loud pedal position sensor 25 for detecting the state of the loud pedal 101 is also used as a sensor for performing feedback control of the loud pedal 101, it is not necessary to provide a special sensor for generating the correction data HD. .

5. 2. Modifications Although the embodiment according to the invention has been described above, the invention is not limited to the embodiment described above, and various modifications described below are possible. In the above-described embodiment, the position of the loud pedal 101 is actually measured by the loud pedal position sensor 24. However, the loud pedal 101 at the time of reproduction is controlled based on the positional information of the loud pedal 101 included in the performance data ED. The drive parameter correction unit 25 includes:
The correction data HD may be generated based on the position information. Further, the drive parameter correction unit 25 may generate the correction data HD based on the position data RD of the loud pedal 101 generated by the control unit 21.

In the above-described embodiment, the correction data HD is generated based on the position of the loud pedal 101 so as to cancel the load fluctuation of the damper 6. However, the present invention is not limited to this.
The drive parameter may be changed based on the state of 1.
For example, the correction data HD may be generated based on the speed or acceleration of the loud pedal 101. Further, the correction data HD may be generated based on the combination of the position, speed, or acceleration of the loud pedal 101 as appropriate. In this case, a speed sensor or an acceleration sensor may be provided as means for detecting the speed and acceleration. However, the speed data is obtained by differentiating the position data output from the loud pedal position sensor 24, and the speed data is further differentiated. Alternatively, the acceleration data may be obtained.

The key driving section 27 drives the key 1 on the basis of error data which is a difference between the corrected position data KD 'and the actually measured position data JD. The driving mechanism is mechanically configured. For this reason, there is a time delay from when the driving parameter is changed to when the key 1 is actually driven, but the orbit of the key 1 may not be accurately reproduced due to the time delay.

For example, if the loud pedal 101 is suddenly returned from the depressed state to the original state, the damper 6
Touches the string 4 in a short time, and the load on the key 1 fluctuates rapidly. Here, it is assumed that the time delay of the key drive is Δt, and that the damper 6 is tied at time T. In this case, the correction data HD is based on only the position data of the loud pedal 101.
Is generated, at time T, the loud pedal 101 returns to the original state, and at this time, the correction data HD reflecting that the damper 6 is connected is generated. However,
The key 1 is actually driven based on the correction data HD generated at time T at time T + Δt. Therefore, if control is performed based only on the position data, it may not be possible to follow the load fluctuation.

On the other hand, when the correction data HD is generated based on the position data and the speed data, the position data after Δt time is predicted from the position data and the speed data,
The correction data HD can be generated based on this. Assuming that the value of the position data is P, the value of the speed data is V, and the value of the predicted position data is P ', P' can be calculated by the following equation. P ′ = P + V · Δt Further, if the value of the acceleration data is A, P ′ can be calculated by the following equation. P ′ = P + V · Δt + ／ · A · Δt ² As described above, by using the speed data and the acceleration data in addition to the position data, the load fluctuation is more accurately canceled, and the operation of the key is accurately reproduced. It becomes possible.

In the above-described embodiment, the correction data HD is actually measured by an experiment. However, the present invention is not limited to this. The correction data HD may be correction data HD obtained by self-learning. . In this case, the correction data HD may be updated at the time of factory shipment or maintenance, or may be updated at the time of performance. Also,
The correction data HD to be updated is supplied to the adder 27 of the key driving unit 27.
The drive parameter correction unit 25 may generate the error data output from the unit 1 so as to reduce the error data. The correction data HD is used to measure a difference between a string striking result based on the same drive instruction value in a state where the loud pedal 101 is depressed (when the damper is loaded) and in a state where the loud pedal 101 is original (when the damper is not loaded). May be used to generate the correction data HD. Also, the difference in the string striking result is measured not only in the two states but also in an intermediate state, and based on these, the correction data H
D may be generated. Further, it may be an interpolation value on a characteristic curve obtained by an experiment.

In the above-described embodiment, the drive parameter to be corrected has been described as an example of a target value. However, the present invention is not limited to this, and may be a servo gain or a fixed force. In short, any parameters may be used as long as they are parameters used in a servo system for driving a key. For example, when the servo gain is to be corrected, the gain of the amplifier 272 shown in FIG. 3 may be adjusted based on the correction data HD. When the fixing force is to be corrected, the fixing force data shown in FIG. 3 may be adjusted based on the correction data HD. Further, a combination of a target value, a servo gain, or a fixing force as appropriate may be a correction target. In the above-described embodiment, the key 1 is driven by the key solenoid position sensor 29.
The key 1 is detected based on the position of the key 1. However, the speed of the key 1 is detected by using a speed sensor instead of the key solenoid position sensor 29, and the key 1 is driven based on the detected speed. Good.

[0041]

As described above, according to the present invention, it is possible to predict the load fluctuation applied to the key according to the state of the loud pedal and cancel the fluctuation, so that the operation of the key can be accurately performed. Can be reproduced. Also,
Since the drive parameters are targeted for correction, the storage capacity of the storage means can be reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram of an automatic piano according to an embodiment of the present invention.

FIG. 2 is a block diagram of a playback system of the automatic piano according to the embodiment.

FIG. 3 is a circuit diagram of a key drive unit of the automatic piano according to the embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Key, ED ... Performance information, 21 ... Control part (data generation means), 24 ... Loud pedal position sensor (state detection means), 25 ... Drive parameter correction part (storage means, correction means), 26 ... Drive parameter change part (Correction means), 27
... Key drive unit (drive means) 101. Loud pedal.

Claims (3)

[Claims] 1. An automatic piano for performing an automatic performance based on performance information indicating a key state and a loud pedal state, wherein the key position data is generated based on the performance information indicating the key state. Generating means; driving means for servo-driving the key so that the position of the key becomes the position indicated by the position data, and setting characteristics of a servo system using driving parameters; and a state for detecting the state of the loud pedal Detection means; storage means for storing correction data for correcting the drive parameter in association with the state of the loud pedal; reading out the correction data from the storage means based on a detection result of the state detection means; And a correcting means for correcting the driving parameters based on the automatic piano. 2. An automatic piano for performing an automatic performance based on performance information indicating a key state and a loud pedal state, wherein data for generating position data of the key based on performance information indicating the key state. Generating means; driving means for servo-driving the key so that the position of the key becomes a position indicated by the position data, and setting characteristics of a servo system using driving parameters; and correction data for correcting the driving parameters. Storage means for storing the correction data in association with the state of the loud pedal, and correction means for reading the correction data from the storage means based on performance information indicating the state of the loud pedal, and correcting the drive parameter based on the correction data. And an automatic piano comprising: 3. The automatic piano according to claim 1, wherein said state detecting means detects the position of said loud pedal, and said storage means stores said correction data in association with said loud pedal position. .