JP4670395B2 - Program for automatically operating automatic piano and keys - Google Patents

Description

  The present invention relates to an automatic piano that automatically performs a performance by driving a keyboard, and more particularly to a program for automatically operating a key, and more particularly, to an improvement in reproducibility of performance by a continuous playing method.

In general, an automatic piano drives a key by selectively energizing a solenoid provided corresponding to each key of an acoustic piano based on performance information, and automatically hits a string with a hammer. Perform an automatic performance. The strength of hammering by the hammer corresponds to the driving speed of the key, and the driving speed of the key corresponds to the current supplied to the solenoid. In such an automatic piano, in order to reproduce the performance performed by the key operation by the performer, the key trajectory at the time of performance can be reproduced accurately, and the subtle nuances and musical expressions of the music can be expressed richly. desirable. In this regard, a conventional automatic piano obtains speed information (reference speed) at a predetermined position (reference point) on a key trajectory based on performance information to be reproduced, and can select an arbitrary trajectory type (straight line, parabola, Others generate key trajectory data in accordance with the other, and drive the solenoid in accordance with the trajectory data (see, for example, Patent Document 1). Also, in this type of automatic piano, the key release is started before the key is fully pushed to the end position, or the so-called half-stroke performance that enters the next key pressing operation in the middle of the key release is reproduced. Along with the trajectory data corresponding to the linear trajectory and the linear trajectory at the time of key release (constant velocity trajectory), a shortened trajectory corresponding to a quadratic curve representing the speed change of the key is calculated, and when shifting from key press to key release There is one that continuously changes the speed of the key by driving the key according to the shortened trajectory (see, for example, Patent Document 2).
JP-A-7-175472 JP-A-9-81125

  By the way, in performance reproduction by an automatic piano, when the operation speed of a key is suddenly changed, such as a performance by a half stroke, especially when a key is played repeatedly, key rage is likely to occur. There are various difficulties such as an increase in string speed. According to the configuration described in Patent Document 2, in the case of half-stroke performance, the key moves along the shortened trajectory before the key stroke position reaches the intersection of the key pressing trajectory and the key releasing trajectory. It has been shown that the above problem can be solved by controlling. However, when the key is driven in a shortened orbit according to the above-mentioned Patent Document 2, the key stroke amplitude is reduced, so that there is a risk that a keystroke error is likely to occur, and the continuous hit performance is insufficient.

  The present invention has been made in view of the above points, and has as its object to provide an automatic piano capable of performing repeated hits more smoothly, and capable of reproducing rich performance nuances and timbres. An object of the present invention is to provide a computer program for automatically operating keys in a piano.

An automatic piano according to the present invention defines a plurality of keys, a driving device for individually driving each of the plurality of keys, and movement of a specific key to be automatically operated based on performance information Therefore, a primary trajectory data generating unit that generates primary trajectory data representing a temporal transition of the position, velocity, and acceleration component of the movement of the specific key, and based on the acceleration component in the primary trajectory data , A jump component indicating a change per unit time of the acceleration component with respect to the movement of the specific key is calculated, and secondary trajectory data in which the primary trajectory data is corrected by the jump component is generated. A trajectory data generation unit, and a control device that biases the driving device to drive the specific key based on the secondary trajectory data. Thus, the specific key is automatically operated in a trajectory according to the secondary trajectory data.

According to the present invention, without directly using the first-order trajectory data generated by a conventionally known method, based on the acceleration component in the first-order trajectory data, with respect to movement of the specific key, the unit of acceleration components A dynamic component indicating a change per time is calculated, and secondary trajectory data obtained by correcting the primary trajectory data is generated by the dynamic component, and the specific key is used in a trajectory corresponding to the secondary trajectory data. It is characterized by being driven and operated automatically. For example, said trajectory represented by the first-order trajectory data includes uniform acceleration section, the secondary trajectory data generating unit, based on the acceleration component of the uniform acceleration section, gradually changing the acceleration between the compartment In this way, the jump component is calculated, and secondary trajectory data corrected so that the acceleration changes in the section corresponding to the uniform acceleration section in the primary trajectory data is generated by the jump component. That is, in the conventional control method, the jump component is calculated so as to gradually change the acceleration in the constant acceleration section, and the constant acceleration in the primary trajectory data is calculated based on the jump component. By generating secondary trajectory data corrected so that the acceleration changes in the section corresponding to the section , the key acceleration can be continuously changed over time. As a result, it is possible to obtain curvilinear trajectory data that can change the displacement, speed, and acceleration of the key more smoothly, and it is possible to reproduce a smoother key operation. Therefore, it becomes possible to express subtle nuances and soft tone of the performance, and to enrich the performance expression by the automatic piano .

As an example, the primary trajectory data generation unit calculates a key-pressed constant speed trajectory when the specific key is pressed at a constant speed and a key release constant speed trajectory when the key is released at a constant speed, respectively. Then, by setting a certain section including the intersection of the key pressing constant velocity trajectory and the key releasing constant velocity trajectory as a constant acceleration interval, calculating a constant acceleration trajectory for switching from key pressing to key releasing, The primary trajectory data is generated by a combination of acceleration trajectories. Then, the secondary trajectory data generation unit may calculate the dynamic component as a certain value at said equal acceleration section, the acceleration in the such as an acceleration section as acceleration changes successively in accordance with a fixed value of the dynamic component by changing the trajectory, to generate the secondary orbital data obtained by correcting the first-order trajectory data. According to this, the acceleration (or decrease) of the key is performed without performing equal acceleration (or deceleration) control in a section where the key release operation is continuously performed from the key release or from the key depression to the key release operation, that is, a section where acceleration control is to be performed. Speed) can be continuously changed, and the key operation in the section can be performed more smoothly. This is extremely effective in terms of improving the performance of repeated hitting keys in an automatic piano, in particular, repeated hitting keys by the so-called half-stroke playing method. That is, a smooth force change is given over the entire trajectory representing continuous hits, and a smoother keystroke can be reproduced. Therefore, it is possible to solve problems such as an increase in the stringing speed at the time of continuous hitting, missing of the stringing, or disturbance of the continuous hitting rhythm. Further, since the trajectory for continuously changing the acceleration of the key according to the present invention has an increased trajectory amplitude as compared to the repeated trajectory by the shortened trajectory disclosed in Patent Document 2, the keystroke mistake at the time of repeated hitting can be reduced. Will be able to.

  The present invention can be constructed and implemented not only as a device invention but also as a method invention. In addition, the present invention can be implemented in the form of a program of a processor such as a computer or a DSP, and can also be implemented in the form of a recording medium storing such a program. Further, as a processor, a general-purpose processor such as a computer that executes an arbitrary software program can be used, and a dedicated processor in which dedicated logic is assembled in hardware may be used.

Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a schematic configuration diagram of an automatic piano according to this embodiment, in which main parts of functional blocks related to an electric control system are extracted and shown together with main parts of a mechanical sound generation mechanism. As shown in FIG. 1, the automatic piano has a plurality of (for example, 88) keys 1 as a mechanical sounding mechanism, an action mechanism 2 for transmitting the movement of the key 1 to the hammer, and a corresponding key 1. A hammer 3 that strikes the string in conjunction with the movement of the string, a string 4 that is hit by the hammer 2, and a damper 5 that stops vibration of the string 4. An electromagnetic solenoid 6 is provided on the lower surface of the rear end of the key 1 as a key driving device for driving the key 1. The key 1 is supported so as to be able to swing up and down with a position penetrating the balance pin P as a general fulcrum, and is in a rest position indicated by a solid line in FIG. 1 when the key is not pressed (when no external force is applied). . When the solenoid 6 is driven (excited), the plunger of the solenoid 6 pushes up the rear end of the key 1, the key 1 swings around the balance pin P, and the front end of the key 1 is lowered, so that the key 1 is pressed. Key operated. When the plunger is lowered according to the demagnetization of the solenoid 6, the key 1 returns to the rest position (key release operation). The key 1 basically strokes up and down between a rest position and an end position (a position indicated by a two-dot chain line in the drawing) in accordance with a performance operation (key depression and key release). At this time, in conjunction with the performance operation, the action mechanism 2 is activated, the damper 5 moves away from the string 4, the vibration suppression of the string 4 is released, and the hammer 3 rotates to strike the string 4. String.

A key sensor 25 for detecting the movement of the key 1 is disposed on the lower surface side of each key 1 of the automatic piano. The key sensor 25 can be constituted by, for example, an optical position sensor that can output continuous position information for all steps of the operation stroke of the key 1. As a schematic configuration example of the key sensor 25, a detected member 26 that cooperates with the key sensor 25 is provided at a position opposite to the key sensor 25 on the lower surface of the key 1, and the detected member 26 with respect to the key sensor 25 according to the stroke displacement of the key 1. By changing the relative position, the relative position of the detected member 26 with respect to the key sensor 25 can be detected as the stroke position of the key 1, and an analog signal representing the position information of the key 1 can be output. As is well known, the speed information can be calculated by appropriately differentiating the position information, so that the speed information of the key 1 can be obtained from the output of the key sensor 25. The output of the key sensor 25 is supplied to both a recording control unit 28 and a servo controller 12 to be described later, and is used for performance information generation / recording processing during performance recording and servo control during performance information reproduction. As a specific configuration example of the optical position sensor applicable as the key sensor 25, a conventionally known appropriate sensor configuration may be adopted, and the configuration is not limited to the optical type and is configured by other appropriate position sensors. It does not matter if it is done.
In the automatic piano, a hammer sensor 27 for detecting the operation of the hammer 3 may be provided. The hammer sensor 27 may be configured in substantially the same manner as the key sensor 25. In this example, the output of the hammer sensor 27 is supplied to a recording control unit 28, which will be described later, and is used when performing performance information generation processing during performance recording.

  The solenoid 6 is provided with a plunger sensor 35 for detecting the movement of the plunger 6a. In this example, the plunger sensor 35 is constituted by an appropriate speed sensor (for example, a moving magnet type speed sensor) for detecting the operation speed of the plunger 6a, and an analog signal corresponding to the moving speed of the plunger 6a when the solenoid 6 is driven is output. Output. The output of the plunger sensor 35 is supplied to a servo controller 12 which will be described later, and is used for servo control during performance information reproduction. In addition, since the structure itself of the moving magnet type speed sensor applicable as the plunger sensor 35 is well-known, detailed description of the structure is abbreviate | omitted. The plunger sensor 35 is not limited to the moving magnet type, and may be constituted by other appropriate speed sensors.

Here, the electrical hardware configuration of the automatic piano will be briefly described with reference to FIG. 2. As shown in FIG. 2, the automatic piano includes a CPU 40, a ROM 41, a RAM 42, and a storage device 43. The devices are connected via a data and address bus 46.
The CPU 40 controls the overall operation of the automatic piano and executes various signal processing such as performance information reproduction processing and performance information recording (performance recording) processing according to key operations. Control programs for various processes executed by the CPU 40 may be stored in the ROM 41, for example. Various data and various parameters generated during the execution of the various processes are stored in an appropriate memory such as the RAM 42 (or ROM 41).

  The storage device 43 is used for writing performance information generated by the performance recording process, storing performance information used when reproducing the performance information, and the like, and includes a hard disk, a flexible disk, a floppy (registered trademark) disk, and a compact disk. (CD-ROM), magneto-optical disk (MO), ZIP disk, DVD (Digital Versatile Disk), semiconductor memory, and the like may be used.

The input / output interface (I / O) 44 includes an AD converter, and detection signals (analog signals) output from the key sensor 25, the hammer sensor 27, and the plunger sensor 35 are converted into digital signals via the I / O 44. To the CPU 40. The CPU 40 performs processing for acquiring the output of each sensor at every predetermined clock timing.
In addition, a solenoid drive signal generated in the CPU 40 during reproduction of performance information, which will be described later, is converted into a PWM-type current signal (hereinafter abbreviated as a PWM signal) via the PWM generator 45 and output to the solenoid 6. In addition, the automatic piano may further include a setting operator group for an operator (user) to select an operation mode, a communication interface connected to an appropriate external device, and the like.

  An outline of the performance recording operation and performance information reproduction operation executed in the automatic piano will be described. In FIG. 1, a recording control unit 28 and a post-recording processing unit 29 correspond to modules related to performance recording processing, and a pre-reproduction processing unit 10, motion controller 11 and servo controller 12 are related to performance information reproduction processing. Various operations such as arithmetic processing performed by these modules are implemented by software programs executed by the CPU 40.

  The recording control unit 28 takes in the outputs of the key sensor 25 and the hammer sensor 27, and based on physical quantities related to the movement of the key 1 and the hammer 3 detected by the key sensor 25 and the hammer sensor 27, various information related to performance events (key pressing speed, key release). Speed, stringing speed, and time information thereof). The post-recording processing unit 29 normalizes the various information obtained by the recording control unit 28 and then generates performance information representing the performance content of the piano performance based on the various information related to these performance events. To do. That is, various pieces of information related to performance events are supplied to the storage device 43 (see FIG. 2) as performance information. Here, the performance information includes performance events to be reproduced and data of time at which the performance events are to be generated, and may be created in an appropriate data format such as a MIDI data format. The normalization process is a process for absorbing individual differences between pianos. The various physical information has an inherent tendency depending on the arrangement position of the sensor in each individual piano, a difference in structure, a mechanical error, and the like. The key-pressing time / key-pressing speed, the key-release time / key-release speed, and the string-pressing time / string-pressing speed are appropriately converted.

  In the pre-reproduction processing unit 10, a key for reproducing the performance content (performance event) represented by the performance information based on performance information supplied from the storage device 43 (see FIG. 2) or a real-time communication device (not shown). Generate orbital data. This trajectory data is supplied to the motion controller 11. The motion controller 11 generates a control signal (target value) for solenoid drive control using the supplied trajectory data, and supplies it to the servo controller 12. The servo controller 12 uses the outputs of the key sensor 25 and the plunger sensor 35 as feedback signals, and performs servo control based on the target value generated by the motion controller 11 and the feedback signal, thereby exciting current to the solenoid 6. (Solenoid drive signal) is controlled. As a result, the key 1 is driven according to the given trajectory data.

The procedure of the orbit data creation process executed in the pre-reproduction processing unit 10 will be described. Here, “orbit” means a change in the position of the key over time.
Patent Document 1 cited above shows an example of a conventionally known principle of trajectory creation. This is a basic parameter for generating trajectory data based on performance information to be reproduced, information on the speed (reference speed) that the key should take at a predetermined position (reference point) on the key trajectory, and the key 1 Calculates a time (reference time) that should pass through the reference point, and generates any kind of trajectory data that passes through the reference point. Here, the reference point is a predetermined stroke position of the key that can be set in advance by experiments or the like. Further, the reference speed and reference time can be calculated based on performance information to be reproduced. The details of the calculation processing for calculating the reference speed and the reference time are shown in Patent Document 1, and the same processing as described in Patent Document 1 may be adopted in this embodiment.

  In this embodiment, first, the key is moved from the rest position xR (position of the key stroke amount 0 mm) to the end position at a constant speed based on the performance information (for example, the stringing speed and the stringing time) corresponding to the key depression event. A key depression trajectory (hereinafter referred to as a key depression constant velocity trajectory) reaching xE (for example, a position depressed 10 mm from the rest position xR) is generated according to the above-described principle of trajectory creation, and a performance corresponding to a key release event. Based on information (for example, key release speed and key release time), a key release trajectory (hereinafter referred to as a key release constant velocity trajectory) in which the key moves at a constant speed from the end position xE to the rest position xR is defined as the trajectory. It shall be generated according to the principle of creation. The rest position xR (position of the key stroke 0 mm) and the end position xE (for example, a position pushed down 10 mm from the rest position xR) are preset as fixed values.

Since it is assumed that the key moves at a constant speed in the key-pressed constant speed trajectory, the initial speed of the key at the time of key pressing is equal to the reference speed, and can be determined as a known value. If the initial speed (= reference speed) at the time of key pressing is the key pressing reference speed vP (where vP> 0), the time from the key driving start time is t, and the key position on the trajectory is X, the key pressing constant speed. The trajectory can be expressed by the following equation (1).
X = vP * t + xR (1)
In the present specification, “*” in mathematical expressions represents multiplication.
By the above equation (1), the key press start time (key press rest start time tPR) and key press end time (key press end arrival time tPE) when reproducing the performance information (key press event) to be reproduced in accordance with the linear trajectory. Can be requested. Then, according to the trajectory data, the key can be controlled to be depressed at a constant speed vP from the key depression rest departure time tPR.

As for the key trajectory at the time of key release, a predetermined reference point (for example, the position of the key 1 when the damper 5 is in contact with the string 4), the reference speed (key release reference speed vN), and the reference time are defined, and the performance information By setting a linear trajectory based on it, a key-released constant velocity trajectory can be obtained. In the key-released constant velocity trajectory, it is assumed that the key moves at a constant velocity, so that the initial speed of the key at the time of key release is equal to the key release reference speed vN (where vN <0). Therefore, if the time from the key driving start time is tN and the key position on the key release constant velocity orbit is XN, the key release constant velocity orbit can be expressed by the following equation (2).
XN = vN * tN + xE. Formula (2)
By the above equation (2), the key release start time (key release end departure time tNE) and key release end time (key release rest arrival time tNR) when reproducing the performance information (key release event) to be reproduced according to the linear trajectory. Can be requested. Then, according to the trajectory data, the key can be controlled to be released at a constant speed vN from the key release end departure time tNE.

  According to the key pressing constant velocity trajectory and the key releasing constant velocity trajectory described above, the movement of the key returning from the end position to the rest position after being pushed down from the rest position to the end position can be reproduced with constant velocity motion. However, in an actual piano performance, not only the trajectory due to the constant velocity movement, but also a performance operation in which the speed changes while the key is being depressed, or the end position is completely pushed like the so-called half stroke (or the rest position). There is a rendition accompanied by a change in the operation speed of the key, such as a rendition in which a key release (or next key press) operation is started before the key is fully returned. With the above constant velocity trajectory, the key trajectory with such a speed change cannot be reproduced appropriately. In addition, in the half-stroke continuous playing method or the like, a key rage is likely to occur, and it is difficult to accurately reproduce the performance. The automatic piano according to this embodiment is characterized in that the above points have been improved when creating a trajectory. That is, it is characterized in that a smooth curved trajectory capable of continuously changing the operation speed and acceleration of the key is generated as necessary, and the driving of the key 1 is controlled based on the trajectory.

  Next, a process for creating a curved track according to the present invention will be described. As an example, a half-stroke playing method in which a key that has been pushed all the way to the end position is pushed back to the end position without being completely returned to the rest position (that is, the key release operation and the key depression operation are repeated with the key half pressed down) The case of creating a trajectory for half-stroke repeated) will be described. FIG. 3A is a track diagram showing an example of a continuous hitting track according to this embodiment. In FIG. 3 (a), the solid line indicates the continuous hitting trajectory (change in the position component with time) according to this embodiment, and the dotted line indicates the trajectory (constant velocity trajectory) due to constant velocity motion. Further, (b) shows the change in the velocity component in the trajectory shown in (a), (c) shows the change in the acceleration component in the trajectory shown in (a), and (d) shows the jump in the trajectory shown in (a). Indicates changes in ingredients. Here, “dynamic” means time differentiation of acceleration. In FIGS. 3B, 3C, and 3D, the solid line represents the change of each component in the continuous hitting track according to this embodiment, and the dotted line represents the change of each component in the constant velocity motion.

As shown by a solid line in FIG. 3A, a series of trajectories representing the key release operation and the key press operation is a key press constant velocity trajectory as described above between the end position xE and a predetermined stroke position. It is expressed by a key-released constant-velocity trajectory, and is expressed by a cubic curve-like curve trajectory in a section in which the key-release operation shifts to the key-press operation. That is, the continuous hitting track is constituted by a combination of a constant velocity track and a curved track. The predetermined stroke position may be appropriately set between the end position xE and the rest position xR so that a natural operation can be given to the key 1. Hereinafter, this position is referred to as a transit position xT. If the constant velocity trajectory is too short, the reproducibility of the key speed becomes unstable. Therefore, the transit position xT may be set slightly closer to the rest position xR than the intermediate position between the end position xE and the rest position xR. Further, in the following description, regarding the time when the key trajectory passes the transit position xT, the time when the key is released is referred to as a key release transit time tNT, and the time when the key is pressed is referred to as a key press transit time tPT.
Specifically, the continuous hitting trajectory shown in FIG. 3A is expressed by a key-released constant velocity trajectory between the end position xE and the transit position xT with respect to the trajectory at the time of key release, from the transit position xT. This is expressed by a curved trajectory (hereinafter referred to as a key release slow-down trajectory) showing a characteristic that the key speed gradually decreases until the key release operation ends. Further, the trajectory at the time of key depression is expressed by a curved trajectory (hereinafter referred to as a key depression slow-up trajectory) showing a characteristic in which the key speed gradually increases from the key depression operation start time to the transit position xT. Then, between the transit position xT and the end position xE is expressed by a key-pressed constant velocity trajectory.

As an example of a procedure for creating a continuous hitting trajectory according to this embodiment, first, a key release constant velocity trajectory and a key pressing constant velocity trajectory are calculated based on performance information, and then the key release constant speed trajectory and key pressing etc. It is determined whether a curved trajectory needs to be created by determining whether or not the fast trajectory intersects. Then, when it is necessary to create a curved trajectory, the curved trajectory is created by a calculation process described later. Here, “the key release constant speed trajectory and the key press constant speed trajectory intersect” means that the key release constant speed trajectory before reaching the rest position xR as shown by the dotted line in the trajectory diagram of FIG. The key trajectory reproduced by the key-released constant-speed trajectory and the key-pressed constant-velocity trajectory is before the return to the rest position. The half stroke starts to press the key. The determination as to whether or not the key-released constant velocity trajectory and the key-pressed constant velocity trajectory intersect can be executed by various conditions or methods, and any conventionally known condition or method may be applied. As an example, if the time at which the key release constant velocity trajectory reaches the end position xE (key release rest arrival time tNR) is later in time than the key press constant velocity trajectory start time (key press rest departure time tPR), 2 It can be determined that two constant velocity trajectories intersect. Note that specific examples of various conditions for determining the intersection between the key-released constant velocity trajectory and the key-pressed constant velocity trajectory are described in detail in, for example, Patent Document 2 described above, and detailed description thereof is omitted here. To do. Even if the key release constant velocity trajectory and the key pressing constant velocity trajectory do not intersect before the rest position xR (position from the end position), the half stroke trajectory is expressed by the combination with the curved trajectory. If the constant velocity trajectory does not intersect, it is further calculated whether the key release slowdown trajectory and the key depression slowup trajectory intersect. You may comprise so that it may investigate. The determination configuration in this case is also described in detail in Patent Document 2.
In this embodiment, for convenience of explanation, it is necessary to create a curved trajectory (a key release slow-down trajectory and a key press slow-up trajectory) only by whether or not the key release constant velocity trajectory and the key press constant velocity trajectory intersect. However, it may be configured to determine the intersection of the key release slow-down trajectory and the key press slow-up trajectory. Further, the performance information may include data that indicates that a curved track should be created in the performance event, and whether or not the curved track needs to be created can be determined based on the data. In short, when it is necessary to drive a key with acceleration characteristics, a curved trajectory (key-release slow-down trajectory and key-press slow-up trajectory) may be created.

When the key release constant velocity trajectory and the key press constant velocity trajectory intersect, a process of creating a curved trajectory (key release slow-down trajectory and key press slow-up trajectory) is performed. Assuming that the position where the key pressing constant velocity trajectory and the key releasing constant velocity trajectory intersect is the constant velocity crossing position xc and the time is the constant velocity crossing time tc, the constant velocity crossing time tc is the key pressing constant velocity trajectory. It can be obtained by calculation from the orbit data of the key-released constant velocity orbit. That is, the constant speed crossing time tc can be calculated by the following equation (3).
tc = (− vN * tNE + vP * tPE) / (− vN + vP) Equation (3)
When calculating the constant time crossing time tc according to the above equation (3), the key release reference speed vN (where <0), the key release end departure time tNE, the key depression reference speed vP (where> 0) and the key depression end. Each arrival time tPE is determined as a known value.

As shown in the figure, since the constant time crossing time tc is the time of transition from the key release operation to the key press operation, the key release slowdown trajectory is the key speed between the key release transit time tNT and the crossing time tc. Is set to gradually decrease from vN to 0, and the key-pressing slow-up trajectory is set so that the key speed gradually increases from 0 to vP from the crossing time tc to the key-press transit transit time tPT. . Further, the section between the key release transit passage time tNT and the key depression transit passage time tPT is a section to which the curved trajectory (the key release slow-down trajectory and the key press slow-up trajectory) according to the present invention is applied.
First, the key release acceleration aN in the key release slow-down trajectory is obtained. Since acceleration is a time derivative of speed, it can be calculated by the following equation (4).
aN = (0−vN) / (tc−tNT) · (4)
The key release transit passage time tNT in the above equation (4) can be calculated by the following equation (5).
tNT = tNE + (xT−xE) / vN · (5)
The transit position xT and end position xE in the above formula (5) are set in advance as fixed values.

Further, the key depression acceleration aP in the key depression slow-up trajectory can be calculated by the following equation (6).
aP = (vP-0) / (tPT-tc) · (6)
Further, the key depression transit passage time tPT in the above equation (6) can be calculated by the following equation (7).
tPT = tPE− (xE−xT) / vP · (7)

By calculating the key release acceleration aN and the key press acceleration aP, a key release slow-down trajectory (trajectory of a speed characteristic that changes at the time of key release) and a key press slow-up as shown by an alternate long and short dash line in FIG. A trajectory (a trajectory of time-varying speed characteristics for key pressing) can be generated. That is, on the basis of the key release acceleration aN and the key press acceleration aP, the key press and key release speed information that changes continuously with the passage of time is obtained, and a curved orbit (represented by a one-dot chain line) that reproduces the continuous speed change. Orbit data of a key release slow-down trajectory and a key press slow-up trajectory). This trajectory is a uniform acceleration trajectory in which the acceleration component is maintained at a certain value (key-release acceleration aN and key-depression acceleration aP) as shown by a one-dot chain line in FIG. The state of the velocity component that continuously changes in the uniform acceleration trajectory is shown by a one-dot chain line in FIG. Note that the generation of a trajectory that continuously changes the speed of the key while keeping the acceleration constant as described above is also disclosed in Patent Document 2.
The trajectory data made up of the position, speed, and acceleration components for automatic key operation obtained by the above processing will be referred to as primary trajectory data. The primary trajectory data is obtained by the prior art, and the acceleration characteristic is a constant acceleration characteristic.

Next, in order to establish the key release slow-down trajectory and the key press slow-up trajectory proposed according to the present invention, the acceleration components (key release acceleration and key press acceleration) are also continuously changed over time. First, the primary trajectory data is corrected. Therefore, in order to calculate acceleration information that changes continuously from the primary trajectory data, the key release acceleration and the key press acceleration that change with time are determined from the acceleration component (equal acceleration characteristic) of the primary trajectory data. A dynamic component as a displacement amount (time differential value) per unit time is obtained.
The key release jump jN in the key release slow-down trajectory can be calculated by the following equation (8).
jN = 2 * aN / (tc−tNT) · (8)
However, in the above formula (8), aN is the key release acceleration in the uniform acceleration trajectory. This means that the acceleration change value per unit time is calculated as the dynamic component jN so that the amount of change in acceleration during the time length “tc−tNT” is twice the aN. Note that the value of the coefficient “2” may be variably adjusted as appropriate in design.
Further, the key depression speed jP in the key depression slow-up trajectory can be calculated by the following equation (9).
jP = 2 * aP / (tPT−tc) · (9)
However, in the above formula (9), aP is the key depression acceleration in the uniform acceleration trajectory. This meaning is also the same as above.

  By obtaining the key release jump jN and the key press jump jP by the above equations (8) and (9), the trajectory data of the key release slow-down trajectory and the key press slow-up trajectory as shown by the solid line in FIG. Can be generated. That is, the trajectory of the uniform acceleration section in the primary trajectory data (the uniform acceleration trajectory indicated by a one-dot chain line) is a key release slow-down trajectory and a key depression slow-up trajectory (unequal acceleration) as indicated by a solid line in FIG. (Orbit) is replaced / corrected, and the corrected data is called secondary trajectory data. According to the key release slow-down trajectory and the key press slow-up trajectory (secondary trajectory data) generated in this way, the crossing time tcJ (= the constant time crossing time tc) of the key release slow-down trajectory and the key press slow-up trajectory is obtained. In a predetermined section (between key release transit time tNT and key press transit time tPT), as shown by a solid line in FIG. 3D, the jump component of the trajectory is set to a certain value (key release jump jN and press key (Key orbit jP) can be kept (this orbit is called an equal orbit). In other words, by managing the dynamic component to a constant value based on the calculated key release movement jN and key release movement jP, the key depression acceleration and the key separation acceleration are represented as time elapses as shown by the solid line in FIG. Can be changed continuously. In this way, by continuously changing the acceleration by the uniform jump trajectory, the speed component can be changed in a curved line as shown by a solid line in FIG. Therefore, according to this embodiment, the key release slow-down trajectory and the key-press slow-up trajectory due to equal swaying move the key displacement, speed, and acceleration more smoothly than the conventional constant velocity trajectory and constant acceleration trajectory. You will be able to control. In addition, the change in acceleration at the start position (key release side transit position) of the key release slowdown trajectory can be made smoother than in the case of the uniform acceleration orbit, so that the key rampage during the key release operation can be effectively prevented. It becomes possible to suppress.

  In FIG. 3 (a), the intersection position xcJ of the key release slow-down trajectory and the key depression slow-up trajectory (trajectory indicated by the solid line) due to the equal movement according to this embodiment is the intersection position xcA of the trajectory due to the constant acceleration indicated by the alternate long and short dash line. Compared to the above, a position closer to the rest position xR is taken. Therefore, according to the key release slow-down trajectory and the key-pressing slow-up trajectory due to the equal movement according to this embodiment, it is possible to expand the key drive amplitude as compared with the trajectory due to the uniform acceleration. Specifically, the intersection position xcA at the time of uniform acceleration (primary trajectory data) was at a substantially middle point between the transit position xT and the uniform speed intersection position xc. On the other hand, the crossing position xcJ at the time of equal jump (secondary trajectory data) is located at a substantially middle point between the crossing position xcA at the time of constant acceleration and the crossing position xc at the time of constant speed. Therefore, according to the orbit of equal sway, the distance from the transit position xT to the crossing position can be approximately 4/3 times that in the case of equal acceleration. By expanding the amplitude of the trajectory in this way, it becomes possible to reduce keystroke mistakes when reproducing trajectory data.

  In accordance with the processing described above, trajectory data is created in the pre-reproduction processing unit 10 (see FIG. 1). The primary trajectory data creation process and secondary trajectory data creation process in the pre-reproduction processing unit 10 are performed by a computer configured so that the CPU 40 (see FIG. 2) executes the above-described calculations and processes. Realized by the program. Alternatively, the present invention is not limited to this, and it may be realized by a dedicated hardware circuit. Of course, if there is no curved trajectory (key-release slow-down trajectory and key-press slow-up trajectory) in the primary trajectory data, the primary trajectory data may be output without modification.

Next, the motion controller 11 (see FIG. 1) uses the created trajectory data (secondary trajectory data or primary trajectory data if it is not created) to control solenoid drive control. A signal (target value) is generated and supplied to the servo controller 12. The servo controller 12 performs servo control based on the supplied control signal and the outputs of the key sensor 25 and the plunger sensor 35.
FIG. 4 is a block diagram functionally showing an example of a servo control system configuration in the automatic piano. In FIG. 4, various arithmetic processes in a feedback loop surrounded by a one-dot chain line are implemented by a software program executed by the CPU 40 (see FIG. 2).

  The target value generation unit 50 is supplied with the key trajectory data (trajectory reference) generated according to the performance information to be reproduced as the target value (reference value) of the servo control. The target value generation unit 50 generates a position target value rx, a speed target value rv, and an acceleration target value ra as target values at a certain time according to the supplied trajectory reference. Here, the position target value rx, the speed target value rv, and the acceleration target value ra are a position component, a velocity component, and an acceleration component in the trajectory data. The target value for each event (position, velocity, acceleration) generated by the target value generation unit 50 is sent in parallel according to a predetermined sample time (for example, every 1 ms). In the figure, “ru” represents a direct output of an electric quantity (current signal) corresponding to a target value. The usage rate of the current signal ru with respect to the entire target value is appropriately determined by experiment. The position target value rx, the speed target value rv, and the acceleration target value ra generated by the target value generation unit 50 are respectively input to the position comparison unit 51, the speed comparison unit 52, and the acceleration comparison unit 53 according to the predetermined sampling time. The

  On the other hand, taking in the output of the key sensor 25 and the plunger sensor 35 will be described. When the solenoid 6 is energized as described above, the key 1 provided corresponding to the energized solenoid 6 is driven. The speed sensor (plunger sensor) 35 detects the moving speed ym of the plunger 6a of the solenoid 6 and outputs an analog detection signal yvma corresponding to the moving speed ym. The AD converter (corresponding to the I / O 44 in FIG. 2) 44a converts the analog detection signal yvma representing the plunger speed output from the speed sensor (plunger sensor) 35 into a digital signal (plunger speed detection value) yvmd.

  The position sensor (key sensor) 25 detects a stroke position yk of the key 1 driven by the solenoid 6 and outputs an analog detection signal yxka corresponding to the stroke position yk of the key. The AD converter (corresponding to the I / O 44 in FIG. 2) 44b converts the analog detection signal yxka output from the position sensor (key sensor) 25 into a digital signal (key position detection value) yxkd.

  The plunger speed detection value yvmd and the key position detection value yxkd converted into digital signals by the AD converters 44a and 44b are supplied to the normalization processing units 54a and 54b, respectively, and the normalization processing units 54a and 54b detect the plunger speed. A predetermined normalization process is performed on each of the value yvmd and the key position detection value yxkd. In the figure, the plunger speed detection value after normalization processing is indicated by “yvm”, and the key position detection value after normalization processing is indicated by “yxk”.

  The speed generation unit 55 generates speed information (key speed value yvk) of the key 1 based on the key position detection value yxk. That is, the speed generation unit 55 calculates key speed information by appropriately differentiating the position information of the key 1 output from the key sensor 25 (for example, polynomial fitting). As an example of a calculation method, key speed information (key speed value yvk) can be calculated by quadratic curve fitting using position information (key position detection value) at seven points before and after a certain sampling time point.

  The position generator 56 generates position information (plunger position value yxm) of the plunger 6a based on the plunger speed detection value yvk. That is, the position generator 56 calculates the position information (plunger position value yxm) of the plunger 6 a by integrating the speed information of the plunger 6 a output from the plunger sensor 35.

  The acceleration generation unit 57 generates acceleration information (plunger acceleration value yam) of the plunger 6a based on the plunger speed detection value yvm. That is, the acceleration generating unit 57 calculates the acceleration information of the plunger 6a by appropriately differentiating the velocity information of the plunger 6a output from the plunger sensor 35 (for example, polynomial fitting). As an example of the calculation method, the acceleration information (plunger acceleration value yam) of the plunger 6a is calculated by quadratic curve fitting using the speed information (plunger speed detection value yvm) at seven points before and after a certain sampling time point. it can.

The speed adjustment unit 58 is supplied with the plunger speed detection value yvm output from the plunger sensor 35 and the key speed value yvk generated by the speed generation unit 55. The speed adjustment unit 58 obtains a speed feedback signal yv by performing a single adjustment of the plunger speed detection value yvm and the key speed value yvk. The speed feedback signal yv is speed information for feedback control obtained from the sensor outputs of both the plunger sensor 35 and the key sensor 25, and is compared with the speed target value rv generated by the target value generation unit 50. Are fed back to the speed comparator 52 (negative feedback).
In the speed adjustment unit 58, specifically, the plunger speed detection value yvm is weighted by a predetermined coefficient Kvm (calculation element 58a), and the key speed value yvk is weighted by a predetermined coefficient Kvk (calculation element). 58b), and the speed feedback signal yv is obtained by adding both at the addition element 58c. Here, both weight coefficients Kvm and Kvk have a relationship of “Kvm + Kvk = 1”, and depending on whether the speed feedback signal yv with emphasis on the plunger speed detection value yvm or the key speed value yvk is obtained. Set to an appropriate value based on the experimental results. As an example of the weighting coefficient based on the experimental result, the coefficient Kvm = 0.7 and the coefficient Kvk = 0.3 can be set.

The position adjustment unit 59 is supplied with the key position detection value yxk output from the key sensor 25 and the plunger position value yxm generated by the position generation unit 56. The position adjustment unit 59 obtains a position feedback signal yx by performing a single adjustment of the key position detection value yxk and the plunger position value yxm. The position feedback signal yx is position information for feedback control obtained from the sensor outputs of both the key sensor 25 and the plunger sensor 35, and this is compared with the position target value rx generated by the target value generation unit 50. Therefore, a feedback input (negative feedback) is made to the position comparison unit 51.
In the position adjustment unit 59, specifically, the key position detection value yxk is weighted by a predetermined coefficient Kxk (calculation element 59a), and the plunger position value yxm is weighted by a predetermined coefficient Kxm (calculation element). 59b), the position feedback signal yx is obtained by adding both by the addition element 59c. Here, both weight coefficients Kxk and Kxm have a relationship of “Kxk + Kxm = 1”, and depending on whether the position feedback signal yx with emphasis on the key position detection value yxk or the plunger position value yxm is obtained. Set to an appropriate value based on the experimental results. As an example of the weighting coefficient based on the experimental result, the coefficient Kxk = 0.9 and the coefficient Kxm = 0.1 can be set.

  Further, the plunger acceleration value yam calculated by the acceleration generation unit 57 is fed back to the acceleration comparison unit 53 for comparison with the acceleration target value ra generated by the target value generation unit 50 as acceleration information for feedback control. Input (negative feedback). It is also conceivable to obtain a key feedback information by further differentiating the key speed value yvk calculated in the speed generation unit 55, and to obtain a position feedback signal by unifying and adjusting the key acceleration information and the plunger acceleration value yam. In this case, however, the key acceleration information is a value obtained by second-order differentiation of the key position detection value yxk, and the signal quality deteriorates. Therefore, this is not performed in this embodiment.

  As described above, based on the outputs of the key sensor 25 and the plunger sensor 35, physical quantity information for feedback control of the same physical quantity as the position, speed, and acceleration target value, that is, the position feedback signal yx, the speed feedback signal yv, and A plunger acceleration value yam is given.

  The position comparison unit 51 is supplied with the position feedback signal yx output from the position adjustment unit 59 and the position target value rx output from the target value generation unit 50. The position comparison unit 51 subtracts the position target value rx and the position feedback signal yx to obtain a position deviation ex that is the difference between rx and yx.

  The speed comparison unit 52 is supplied with the speed feedback signal yv output from the speed adjustment unit 58 and the speed target value rv output from the target value generation unit 50. The speed comparison unit 52 subtracts the position target value rv and the position feedback signal yv to obtain a speed deviation ev that is a difference between rv and yv.

  The acceleration comparison unit 53 is supplied with the plunger acceleration value yam output from the acceleration generation unit 57 and the acceleration target value ra output from the target value generation unit 50. The acceleration comparison unit 53 subtracts the acceleration target value ra and the plunger acceleration value yam to obtain an acceleration deviation ea that is a difference between ra and yam. Here, since the acceleration target value ra is included as a servo control element, it is possible to more directly manage the dynamic component at the time of key driving. In this embodiment, in the case of reproducing the same dynamic trajectory in which the acceleration is continuously changed as described above, the driving of the key will be controlled so as to keep the dynamic component at a certain value.

  The position deviation ex is amplified by the position servo gain Kx via the amplifying unit 60a, and is supplied to the adding unit 61 as a position control signal ux. Further, the speed deviation ev is amplified by the speed servo gain Kv via the amplifying part 60b and supplied to the adding part 61 as a speed control signal uv. The acceleration deviation ea is amplified by the acceleration servo gain Ka via the amplifying unit 60c and supplied to the adding unit 61 as an acceleration control signal ua. The gain coefficients Kx, Kv, and Ka to be multiplied by each of the position deviation ex, the speed deviation ev, and the acceleration deviation ea may be appropriately set by experiment. As a numerical example of the gain coefficient, a position servo gain Kx = 1.7. The values of speed servo gain = 3.5 and acceleration servo gain = 0.5 can be set. According to an example of the gain coefficient, the focus of servo control is placed on the speed component.

  The adder 61 adds the position control signal ux, the speed control signal uv, and the acceleration control signal ua to unify the control signals for these events. Then, the solenoid drive signal u is generated by further adding the target value current signal ru to the addition result (addition element 62).

The solenoid drive signal u is converted into a PWM-type solenoid excitation current signal ui via the PWM converter 45, and the solenoid 6 is driven based on the excitation current signal ui.
According to the servo control system described above, the solenoid drive signal u reflecting the movement of the solenoid 6 directly subject to servo control and the movement of the key 1 driven by the solenoid 6 is generated. By driving the solenoid 6 with the excitation current signal ui corresponding to the key 1, the key 1 can be operated more accurately with respect to the target value, and the given trajectory reference can be reproduced more precisely. Further, according to the servo control system shown in FIG. 4, the feedback signal for each event of position, velocity and acceleration generated from the output of the key sensor 25 as a position sensor and the output of the plunger sensor 35 as a velocity sensor, and the position, velocity and By realizing the hybrid type servo control based on the target value of each acceleration event, a higher performance automatic piano can be realized. In this servo control system, speed information generated by differentiating the output of the position sensor (key sensor 25), position information generated by integrating the output of the speed sensor (plunger sensor 35), and output of the speed sensor. The acceleration information generated by differentiating is used. In this regard, from the standpoint of position control of the hybrid type servo control, the speed servo control functions as a differential compensator. From this standpoint, the position servo control functions as an integral compensator and the acceleration servo functions as a differential compensator.

  FIG. 5 is a graph showing an actual measurement example of a control result when the constant dynamic striking trajectory described with reference to FIG. 3A is reproduced by servo control having the configuration shown in FIG. In the figure, the position component (position target value rx) of the continuous hitting trajectory data is indicated by a broken line, and the actual measurement value yxk of the position data of the key 1 driven repeatedly is indicated by a solid line. The speed component (speed target value rv) of the continuous hitting trajectory data is indicated by a one-dot chain line, and the acceleration component (acceleration target value ra) of the continuous hitting trajectory data is indicated by a two-dot chain line. The horizontal axis represents time t. As described above, according to the key release slow-down trajectory and key press slow-up trajectory according to this embodiment, the acceleration component (acceleration target value ra) is continuously changed, so that the entire hitting trajectory is smooth. Can be given to the key. For this reason, as shown in FIG. 5, it is possible to obtain an actual measurement value yxk of the position data of the key 1 that is extremely accurate (approximate) with respect to the position target value rx of the continuous hitting trajectory. Therefore, according to the constant dynamic continuous striking trajectory according to this embodiment, it is possible to perform a smooth keystroke and improve the repeated striking performance. Further, since the acceleration change of the key becomes smooth (continuous), it is possible to improve the problem that the string striking speed increases at the time of continuous hitting.

  In the above-described embodiment, the creation of the repetitive striking trajectory by equal swaying has been described. However, the application example of the uniform swaying trajectory according to the present invention is not limited to this, and the isocracking trajectory according to the present invention is a full stroke. It is also possible to apply to a single key. The characteristics when the equal dynamic trajectory according to the present invention is applied to a single keystroke will be described with reference to FIGS. FIGS. 6A to 6C are trajectory diagrams showing a trajectory for single keystroke at a key final velocity of 80 mm / s, from a rest position (position of 0 mm stroke) to an end position (stroke amount from the rest position). This represents a trajectory in which the key is depressed to a position of 10 mm), stopped for an appropriate time at the end position, and then returned to the rest position (key release operation). (A) shows a trajectory by equal sway, (b) shows a trajectory by constant velocity, and (c) shows a trajectory by constant acceleration. In each of FIGS. 6A to 6C, the position component of the trajectory is indicated by a solid line, the velocity component is indicated by a dotted line, and the acceleration component is indicated by a one-dot chain line.

As shown in FIG. 6 (a), the key depression slow-up trajectory due to equal swaying moves from the rest position x0 (stroke 0 mm) to the initial velocity v0 = 0 mm / s and the initial acceleration a0 = 0 mm / s ^ 2 ( s ^ 2 "represents the square of the second s), and the trajectory stops at the end position x1 (stroke amount: 10 mm) and the final velocity v1 = 80 mm / s and the final acceleration a1 = about 427 mm / s ^ 2. It becomes. This trajectory is a slow-up trajectory that is kept constant (equal dynamic) at a dynamic j0 = about 1138 mm / s ^ 3 (where "s ^ 3" represents the cube of seconds s). The time required for the key to reach the end position x1 from the rest position x0 according to this trajectory is 375 ms. During the key release operation, the end position x1 starts to operate at an initial speed v2 = −80 mm / s and an initial acceleration a2 = about 427 mm / s ^ 2, and at the rest position x0, the final speed v3 = 0 mm / s and the final acceleration. The slowdown trajectory stops at a3 = 0 mm / s ^ 2, and the required time from the end position x1 to the rest position x0 is 375 ms.
On the other hand, in the case of the uniform speed shown in (b), the trajectory starts from the rest position x0 at the initial speed v0 = 80 mm / s and moves to the end position x1 at the constant speed v0 = 80 mm / s. Therefore, the time required for the key to reach the end position x1 from the rest position x0 along this trajectory is 125 ms. Since the constant velocity trajectory at the time of key release operates from the end position x1 to the rest position x0 at a constant velocity v2 = −80 mm / s, the required time is 125 ms. In the case of the uniform acceleration shown in (c), the operation starts from the rest position x0 at the initial speed v0 = 0 mm / s, moves to the end position x1 at the constant acceleration a0 = 320 mm / s ^ 2, and finally The speed v1 = 80 mm / s. It takes 250 ms for the key to reach the end position x1 from the rest position x0 according to this trajectory. The key release slow-down trajectory in this case is a trajectory that starts operation at the initial speed v2 = −80 mm / s and slows down at the constant acceleration a2 = 320 mm / s ^ 2, and the final speed v1 = at the rest position x0. 80 mm / s. It takes 250 ms for the key to reach the rest position x0 from the end position x1 along this trajectory.

  As is clear from FIGS. 6 (a) to 6 (c), according to the isokinetic trajectory, the slow-up trajectory and the slow-down trajectory at a slower speed than the trajectory with the constant velocity and further with the constant acceleration are used. It becomes possible to express. Therefore, according to the slow-up / slow-down trajectory with equal dynamics, it is possible to reproduce a smoother key pressing operation with a single keystroke, expressing a more polite (soft touch) finger keystroke, It is possible to generate a performance sound with a softer tone. Also in the case of key release, it is possible to reproduce a slower and more relaxed key release operation, and thereby, for example, the attenuation of sound due to stop sound can be made more gradual. As described above, since it is possible to reproduce more gentle key pressing and key releasing operations, for example, smooth key pressing and key releasing operations performed by the player with feelings can be expressed by orbit data. It becomes like this. Therefore, in an automatic piano, it becomes possible to reproduce a player's feeling etc. delicately and precisely.

In the example of the trajectory shown in FIGS. 3 (a) to 3 (d) described above, half-stroke continuous playing (ie, starting from the end position and completely pushing back to the end position without completely returning to the rest position (ie, In the state where the key is pressed halfway down, half-stroke repeated hitting that repeats the key release operation and key pressing operation) has been described. However, the continuous hitting trajectory to which the present invention can be applied is not limited to the above, but from the rest position Any type of continuous hitting trajectory may be used, such as a type of continuous hitting trajectory in which the key pressing is started and the key release is started without being fully pressed to the end position and the operation is returned to the rest position again. Moreover, in the continuous hitting trajectory according to the above-described embodiment, an example in which a part of the trajectory is represented by a constant velocity trajectory has been described. Is also possible. In addition, according to the present invention, it is possible to perform a single-stroke key that follows a key-released slow-down trajectory by pressing the key following the key-pressing constant velocity trajectory and the key release following the key pressing by the same-key movement. According to the key depression slow-up trajectory, the key release following the key depression can be performed by a single stroke key following the key-released constant velocity trajectory. Furthermore, it is possible to perform single keystrokes according to key release slow-up trajectories by releasing keys according to the key release slow-down trajectory according to the key release slow-up trajectory according to the key release slow-up trajectory. Accordingly, it is possible to perform a single keystroke following a key-pressed constant velocity trajectory for the key depression following the key release. It is also possible to perform a repetitive hit performance combining these single hit keys.
In the above example, the generation of trajectory data for driving the key 1 has been described. However, the present invention is not limited to this. For example, the isokinetic trajectory according to the present invention is added to the trajectory data for automatically driving a pedal or the like. It is also possible to apply. The form of the automatic piano according to the present invention may be either a grand piano or an upright piano.

The figure which shows the whole structure of the automatic piano which concerns on one Example of this invention. The block diagram which shows the electrical hardware constitutions in the automatic piano which concerns on the Example. It is a track | orbit figure which shows an example of the continuous hitting track | orbit of the key which concerns on the Example, (a) shows the position component of this repeated hitting track, (b) shows the velocity component of this repeated hitting track, (c) is this repeated hitting track. The acceleration component of the trajectory is shown, and (b) shows the dynamic component of the continuous hitting trajectory. The functional block diagram which shows the servo control system structural example of the automatic piano which concerns on the Example. The graph which shows the example of a measurement which shows the control result at the time of driving-controlling a key according to the track data of the continuous striking track based on the Example. FIG. 5A is a modified example of the above embodiment, in which FIG. 5A is a trajectory diagram in the case where the equal dynamic trajectory according to the present invention is applied to a single keystroke, and FIG. (C) shows the trajectory of a single keystroke with a constant acceleration known conventionally.

Explanation of symbols

  1 key, 2 action mechanism, 3 hammer, 4 strings, 5 damper, 6 electromagnetic solenoid, 6a plunger, 10 playback pre-processing unit, 11 motion controller, 12 servo controller, 25 key sensor, 27 hammer sensor, 28 recording control unit, 29 Post-recording processing section, 35 Plunger sensor

Claims (5)

Multiple keys,
A driving device for individually driving each of the plurality of keys;
Based on the performance information, in order to define the movement of a specific key to be automatically operated, primary trajectory data representing the temporal transition of the position, velocity and acceleration components of the specific key movement is generated. A primary trajectory data generator;
Based on the acceleration component in the primary trajectory data , a dynamic component indicating a change per unit time of the acceleration component with respect to the movement of the specific key is calculated, and the primary trajectory data is corrected by the dynamic component. A secondary trajectory data generating unit for generating secondary trajectory data;
An automatic piano comprising: a control device that biases the driving device to drive the specific key based on the secondary trajectory data. The trajectory represented by the primary trajectory data includes a constant acceleration interval ,
The secondary trajectory data generation unit calculates the jump component so as to gradually change the acceleration in the interval based on the acceleration component of the constant acceleration interval, and the jump component in the primary trajectory data is calculated based on the jump component. 2. The automatic piano according to claim 1, wherein secondary trajectory data corrected so that acceleration changes in a section corresponding to a uniform acceleration section is generated. The secondary trajectory data generation unit corrects the primary trajectory data so that the acceleration sequentially changes by increasing / decreasing the value of the dynamic component, and accordingly, acceleration is performed in a section corresponding to the uniform acceleration section . There piano of claim 2, wherein generating a modified said secondary orbital data were to vary. The primary trajectory data generation unit calculates a key-pressed constant velocity trajectory when the specific key is pressed at a constant speed and a key-released constant velocity trajectory when the key is released at a constant speed, respectively. Set a certain section including the intersection of the key-pressed constant-speed trajectory and the key-released constant-speed trajectory as the constant-acceleration section, calculate the constant-acceleration trajectory that switches from key-pressing to key-release, Generating the primary trajectory data by combination;
The secondary trajectory data generation unit may calculate the dynamic component as a certain value at said equal acceleration section, the trajectory of acceleration in the such as an acceleration section as acceleration changes successively in accordance with a fixed value of the dynamic component piano according to claim 1, wherein the benzalkonium generate the secondary orbital data obtained by correcting the first-order trajectory data by changing the. In an automatic piano having a plurality of keys and a driving device for individually driving each of the plurality of keys, the driving device causes a computer to execute a process for automatically operating keys based on performance information a program for, in the computer,
Generating primary trajectory data representing the temporal transition of the position, velocity and acceleration of the specific key to define the movement of the specific key to be automatically operated based on the performance information;
Based on the acceleration component in the primary trajectory data , a dynamic component indicating a change per unit time of the acceleration component with respect to the movement of the specific key is calculated, and the primary trajectory data is corrected by the dynamic component. A procedure for generating secondary trajectory data;
A program for executing a procedure for driving the driving device to automatically operate the specific key based on the secondary trajectory data .

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