JPH10274980A - Position measurement device for hammer sensor and playing data correction device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the position measurement device of a hammer sensor capable of not only quickly and accurately measuring the position of a sensor but also minimizing a manufacture cost. SOLUTION: String contact time dtE from the string hitting time tPE when a hammer starts hitting a string to the string leaving time tNE is decided based on a keyboard number relating to a pressed key. By using a sensor distance dxE, the time tPM1 and tPM2 detected by the sensor, a distance dxM between a first position xPM1 and a second position xPM2, the string hitting time tPE and the string separation time tNE, mathematical expressions for indicating the inclination of the string hitting straight track and string leaving straight track of the hammer are respectively prepared. Then, from the relation that the difference of the string leaving time tNE and the string hitting time tPE is the string contact time dtE, the string hitting time tPE and the string leaving time tNE in the mathematical expressions are eliminated and the sensor distance dxE is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for measuring the position of a sensor in a keyboard musical instrument in which movement of a hammer during performance is detected and recorded by a sensor. Also,
The present invention relates to an apparatus that corrects a record of an operation of a hammer according to a measurement result of a position of a sensor.

[0002]

2. Description of the Related Art For example, in an automatic piano, when recording performance information, the speed of a hammer immediately before striking a string is detected.
This is recorded as the stringing speed indicating the stringing strength, and the time at which the hammer passes the stringing position is recorded as the stringing time. For example, two optical sensors such as a photo interrupter are arranged side by side near a string, and after the shutter attached to the hammer shank passes through the optical axis of the first optical sensor, the light of the second optical sensor By measuring the time required to pass through the axis, the striking speed is detected. The timing at which the shutter passes through the optical axis of the second optical sensor is detected as the time at which the hammer passes the stringing position.

On the other hand, when reproducing recorded performance information, a key press by a solenoid is started shortly before the string striking time, in anticipation of a time difference from when the key is started to when the hammer actually strikes the string. . In addition, since the time from the start of key pressing to the striking of a sound differs between a strong sound and a weak sound, an automatic piano has been developed in which the key pressing timing by a solenoid is adjusted according to the string striking speed. In any case, the key pressing timing is set so that the hammer strikes the string at the string striking time.

[0004] If the position of the optical sensor closer to the string varies from string to string, the recorded striking time varies from string to string. The chord tone changes when it is generated. Also, at the time of a weak hit, the movement speed decreases until the hammer separates from the action and reaches the string, so that the variation in the string timing appears more remarkably,
The hammer speed at the time of string striking also varies. Therefore, in order to record the performance more accurately, it is necessary to improve the accuracy of the mounting position of the optical sensor.

When adjusting the position of the optical sensor in a factory, for example, two types of gap gauges having different thicknesses are prepared, and when the hammer is brought into contact with the gap gauge applied to the string, each gap gauge is provided. A method of adjusting the position of the optical sensor so that the optical sensor is turned on at a position intermediate the position of the hammer when using the hammer is adopted. Further, a method of measuring the position of the hammer shank when the hammer is moved toward the string and the optical sensor closer to the string is turned on and the position of the hammer shank when the hammer is applied to the string by a laser displacement meter has also been attempted. . Further, a method of attaching a gray scale to a hammer and measuring the position with a photo interrupter is also being studied.

[0006]

However, in the above-mentioned adjustment method, since the position of the optical sensor must be adjusted for each string, there is a problem that it takes a considerable time to adjust all the strings. Was. Also, since the position of the hammer when the hammer is applied to the string must be measured, for example, with a hammer made of felt, the change in the amount of deformation of the hammer when applied to the string directly changes the measurement position of the optical sensor. It results in variation. Furthermore, since a clearance gauge, a laser displacement gauge, and the like must be set on the automatic piano, there is a problem that a changeover of the setup takes time.
In particular, when a measuring device such as a laser displacement meter is used, an adjusting device becomes expensive, and mounting on an automatic piano is practically impossible. Further, since it is necessary to detect ON of the optical sensor while moving the hammer itself, it is impossible to automatically measure the position of the optical sensor while depressing a key, for example.

The present invention has been made in view of the above-mentioned circumstances, and it is possible to quickly and accurately measure the position of a sensor such as an optical sensor, and to minimize the manufacturing cost. It is an object of the present invention to provide a position measuring device for a hammer sensor. Another object of the present invention is to provide a performance recording device that can correct performance information based on the result of measuring the position of a hammer sensor, and thus can accurately record and reproduce a performance.

[0008]

According to a first aspect of the present invention, there is provided a position measuring device for a hammer sensor, wherein the passage of a hammer mechanism, which is rotated by a key depression, to a first position and a first position. A sensor that detects at a second position closer to the string, and a sensor corresponding to a distance between the second position and the string based on a time difference between detection times of the sensor at the first and second positions. A sensor distance information generating means for generating position information.

According to a second aspect of the present invention, in the hammer sensor position measuring device according to the first aspect, the sensor distance information generating means includes a time difference between the detection times and a string contact time when the hammer mechanism is in contact with the string. And generating information corresponding to the distance between the second position and the string based on

According to a third aspect of the present invention, in the hammer sensor position measuring device according to the first aspect, the sensor distance information generating means is configured to determine the second position based on the time differences obtained by a plurality of key presses. And generating information corresponding to a distance between the string and the string.

According to a fourth aspect of the present invention, in the position measuring device for a hammer sensor according to any one of the first to third aspects, the sensor distance information generating means obtains a speed of the hammer mechanism from a time difference between the detection times. And generating information corresponding to a distance between the second position and the string with reference to FIG.

According to a fifth aspect of the present invention, there is provided a performance data correcting apparatus.
A sensor that detects passage of a hammer mechanism that is rotated by a key press at a first position and a second position closer to a string than the sensor, and a time difference between detection times at the first and second positions of the sensor. A sensor distance information generating means for generating sensor position information corresponding to a distance between the second position and the string; a speed calculating means for obtaining a hammer speed of the hammer mechanism based on the time difference; Calculating means for calculating a string starting time of the hammer mechanism based on the speed determined by the calculating means and the sensor position information.

According to a sixth aspect of the present invention, there is provided a performance data correcting apparatus.
According to a fifth aspect of the present invention, the calculation means corrects at least one of the string striking time and the string striking speed in accordance with a deceleration trajectory of the hammer mechanism toward the string striking.

(Operation) In the position measuring device for a hammer sensor according to the first aspect, the time at which the hammer mechanism passes through the first position and the second position is detected to calculate the hammer speed. The calculation means performs an appropriate calculation using the calculated hammer speed to calculate a sensor distance that the hammer mechanism moves after passing the second position and before starting stringing. In the performance data correction device according to the fourth aspect, since the calculating means calculates the stringing time at which the hammer mechanism starts stringing based on the sensor distance and the hammer speed,
The string striking time is corrected according to the sensor distance.

In the position measuring device for a hammer sensor according to the second aspect, mathematical expressions indicating the inclinations of the striking straight path and the straight string path of the hammer mechanism are created. Each equation includes three unknowns, a string striking time, a string releasing time, and a sensor distance, and three equations obtained by adding a relational expression of “string contact time = string releasing time−string striking time” to the above two equations. The sensor distance is obtained by solving a ternary simultaneous equation consisting of

In the position measuring device for a hammer sensor according to the third aspect, four mathematical expressions representing the inclinations of the striking linear trajectory and the separating linear trajectory of the hammer mechanism are generated for the key depression performed twice. Each equation includes five unknowns, two stringing times and a string separation time and a sensor distance. Assuming that the key contact time (unknown number) of the key press performed twice is equal,
The sensor distance is determined by creating two relational expressions of “string contact time = string separation time−string striking time” and solving a six-way simultaneous equation composed of these six mathematical expressions.

A hammer mechanism that rotates by pressing a key generally makes a free movement from the middle of the rotation to reach the strings. Therefore, after starting the free movement, the hammer speed decreases due to the influence of gravity and the like. In the performance data correction device according to the fifth aspect, since the string striking time is corrected based on the deceleration trajectory, the string striking time can be made closer to the actual string striking time. Further, since the string striking speed is corrected based on the deceleration trajectory, the actual string striking speed can be reproduced more faithfully when the performance is reproduced.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION

A: First Embodiment (a) Configuration of Embodiment First, the configuration of a position measuring device for a hammer sensor, which is one of the embodiments of the present invention, will be described. FIG. 1 is a block diagram showing the configuration of the first embodiment of the present invention. In the figure, 1 is a key, and 3 is an action for transmitting the movement of the key 1 to the hammer 2. Reference numeral 4 denotes a string struck by the hammer 2, and reference numeral 5 denotes a solenoid for driving the key 1, which has a configuration similar to that of a normal piano, and a detailed description thereof will be omitted. The solenoid 5 is provided with a sensor for detecting the position of the plunger. And the solenoid 5
When the plunger protrudes, the key 1 rotates around the balance pin P, the player's side lowers, and in conjunction with this, the action 3 operates, the damper 6 separates from the string 4, and the hammer 2 Rotate and strike. 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.

In the drawing, SE1 and SE2 are optical sensors (sensors), and the distance dxM between them is set to a predetermined dimension dxM. The performance detection unit 30 includes the hammer 2
By detecting the time at which the sensor passes through the sensors SE1 and SE2 and measuring the time at which the sensor passes through the sensors SE1 and SE2, the striking speed vP and the string releasing speed vN of the hammer 2 are measured. The performance detection unit 30 detects the time at which the hammer 2 passes through the sensor SE2 as the stringing time. In order to make the stringing time detected by the sensor SE2 closer to the time when the hammer 2 actually strikes the string, the sensor SE2 is provided at a position close to the stringing position of the hammer 2.

Next, reference numeral 26 shown in the figure denotes a plate-shaped shutter attached to the lower surface of the key 1. Reference numeral 25 denotes a key sensor composed of two sets of photo sensors provided at a predetermined distance in the vertical direction. When the key 1 starts to be pressed, the upper photo sensor is first shielded from light, and then the lower photo sensor is shielded from light. Is done. At the time of key release, the lower photo sensor is in a light receiving state, and then the upper sensor is in a light receiving state.

The output signal of the key sensor 25 is supplied to the performance detection unit 30. The performance detection unit 30 performs a process from when the lower photo sensor in the key sensor 25 is in the light receiving state to when the upper photo sensor is in the light receiving state. The time is measured, from which the key release speed is detected. The performance detection unit 30 detects the time at which the upper photo sensor enters the light receiving state as the key release time.

That is, when the performance is started, the performance detecting section 30 detects the stringing time and the stringing speed based on the output signals of the sensors SE1 and SE2, and based on the output signal of the key sensor 25. The key release time and key release speed are detected. Each piece of information detected as described above is supplied to the post-detection processing unit 31. The post-detection processing unit 31 is configured by a CPU having various registers and the like, and measures a distance from the position of the hammer 2 when passing through the sensor SE2 to the position of the hammer 2 where the striking of the string 4 is started (hereinafter referred to as a sensor distance). ) DxE is calculated based on the position measurement principle described later, and is supplied to an internal memory as dimensional data.

Reference numeral 10 denotes a pre-reproduction processing unit which generates position data of the key 1 based on performance data supplied from a recording medium or a real-time communication device. The data is supplied to the motion controller 11. The motion controller 11 supplies an exciting current to the solenoid 5 based on the supplied position data.

(B) Position Measurement Principle Next, the measurement principle of the hammer sensor position measurement device will be described. FIG. 2 shows a position xR of the hammer 2 in a state where the key is not pressed (hereinafter referred to as a rest position) and a position xE in which the hammer 2 starts striking the string 4 (hereinafter referred to as a string striking position) xE. The trajectory of the hammer 2 between them is shown, the horizontal axis represents time, and the vertical axis represents the distance of the hammer 2 to the chord 4.
The hammer 2 that has left the rest position xR by pressing the key moves at a constant speed vP and reaches the string striking position xE, and the string striking position xE.
Can be regarded as moving at a constant speed vN to reach the rest position xR, so that the trajectory of the hammer 2 can be shown as a straight trajectory as shown in FIG.

[0025] Then, the hammer 2 leaving the rest position by key depression, first, after passing through the optical sensor SE1 time TPM _1, passes through the optical sensor SE2 time TPM _2, strikes the strings 4 subsequent time tPE Begin to. The hammer 2 is in contact with the string 4 for a predetermined time dtE (hereinafter, this time is referred to as a string contact time) and leaves the string striking position xE at the string release time tNE.
Again it passes through the optical sensor SE2 time TNM _2, passes through the light sensor SE1 time TNM1. Here, the stringing speed vP of the hammer 2 can be represented by the following equation 1 using the sensor distance dxE.

(Equation 1)

Next, at the time of string striking, the hammer 2 detects the light sensor SE1.
And SE2 are defined as xPM ₁ , xP
When M _2, their distance (xPM ₂ -xPM ₁₎ is
It can be considered that it is equal to the distance dxM between the optical sensors SE1 and SE2. Further, the positions where the hammer 2 passes through the optical sensors SE2 and SE1 when the strings are separated are represented by x, respectively.
Assuming that NM ₁ and xNM ₂ , their distance (xNM ₂ −x
NM ₁ ) can also be considered equal to the distance d × M.
Therefore, the string separation speed vN of the hammer 2 can be represented by the following equation (2).

(Equation 2)

As described above, the string hitting speed vP and the string releasing speed vN of the hammer 2 are measured by the performance detector 30. Therefore, the unknowns in Equations 1 and 2 are, except for the sensor distance dxE to be obtained, the string striking time tPE and the string leaving time t
NE, there is a relationship shown in the following equation 3 between these and the tangling time dtE.

(Equation 3)

Here, it has been discovered by the present inventors that the string contact time dtE is mainly determined by the keyboard number (also referred to as a note number) and is not significantly affected by the string striking speed vP. FIG. 4 is a diagram showing the relationship between the keyboard number and the string contact time dtE. As shown in FIG. 4, it was found that the string-attaching time dtE became shorter as the keyboard number became larger, and the change became almost linear. Note that the string contact time d
It is considered that the reason why tE is determined by the keyboard number is that the string contact time dtE is closely related to the period of the string. Therefore, the string contact time dtE can be obtained by the following equation 4 when the keyboard number is k. Note that in Equation 4, a
And b are coefficients, which can be determined experimentally.

(Equation 4) The relationship between the keyboard number k obtained in the experiment and the string contact time dtE is stored in a memory as a table, and when a key is pressed, the keyboard number k is detected. It is also possible to read out the tangling time dtE corresponding to k.

Therefore, if the tangling time dtE is obtained by the equation (4), tNE and tP are obtained by using the above equations (1) to (3).
By eliminating E, the following equation 5 for calculating the sensor distance dxE can be obtained.

(Equation 5)

(C) Operation of the Embodiment Next, the operation of the hammer sensor position measuring device having the above configuration will be described. FIG. 5 is a flowchart showing the operation of the position measuring device of the hammer sensor. In this embodiment, the performance data for driving the key 1 for measuring the position of the hammer sensor is recorded on a built-in recording medium, or the performance data is supplied from outside.
First, the reproduction preprocessing unit 10 reads performance data from a recording medium or receives performance data supplied from the outside. The performance data is composed of a plurality of event data which are sequentially depressed from the key 1 of the keyboard number # 1 to the key 1 of the last keyboard number (for example, # 88), and each event data is a key indicating the keyboard number. It includes a key, a key-on signal indicating a key-on time, a key-off signal indicating a key-off time, and a key velocity signal indicating a key-on speed. And
When the pre-playback processing unit 10 receives the event data of the keyboard number # 1 as the first event data, the post-detection processing unit 3
1 stores “1” indicating the keyboard number in a register (step S1).

Next, the motion controller 11 drives the key 1 of the keyboard number # 1 by the actuator 5 according to the key pressing speed indicated by the key velocity (step S2). As a result, when the hammer 2 rotates, the performance detection unit 30
The time tPM1 at which the hammer 2 passes the optical sensor SE1 and the time tPM2 at which the hammer 2 passes the optical sensor SE2 are detected.
The performance detection unit 30 measures the time (tPM2−tPM1) required for the hammer 2 to pass from the optical sensor SE1 to pass through the optical sensor SE2.
−tPM1), the distance d between the optical sensors SE1 and SE2
The string striking speed vP is calculated by dividing xM (step S
3).

Next, when the hammer 2 starts hitting the string 4 and the string contact time dtE has elapsed, the hammer 2 separates from the string 4 and returns to rotation. At this time, the performance detection unit 30 detects a time tNM2 at which the hammer 2 passes through the optical sensor SE2 and a time tNM1 at which the hammer 2 passes through the optical sensor SE1. Further, the performance detection unit 30 determines the time (tNM) required for the hammer 2 to pass from the optical sensor SE2 to pass through the optical sensor SE1.
1−tMN2), and this time (tNM1−tMN2)
The string separation speed vN is calculated by dividing the sensor distance dxM by (step S4).

Next, the post-detection processing unit 31 calculates
The distance dxE between the optical sensor SE2 and the string 4 is calculated by using Expression 5 (Step S5). That is, the post-detection processing unit 3
1 is “1” indicating the keyboard number # 1 stored in the register
With reference to this, 1 is substituted for n in Equation 4 to calculate the tangling time dtE. Further, the post-detection processing unit 31 calculates the string striking speed vP and the string releasing speed vN calculated as described above, the detected time tPM2 and the time tNM1, and the sensor distance dxM.
Is substituted into Equation 5 to calculate the sensor distance dxE. The calculated sensor distance dxE is recorded in the memory (step S
6) Go to step 7 to increment the data stored in the register by one.

Then, the process proceeds to a step S8, wherein it is determined whether or not "2" stored in the register is valid as a keyboard number. In this case, since the keyboard number # 2 exists, the determination result in the step S8 is "YES", and the process returns to the step S2 and repeats the steps up to the step S8. In this way, the sensor distance dxE is sequentially calculated for each keyboard number and recorded in the memory. And the last keyboard number (# 88)
Is performed, the data stored in the register is incremented to “89”.
However, since the keyboard number # 89 does not exist, the determination result in the step S8 is "NO", and the measurement ends.

As described above, in the hammer sensor position measuring device having the above-described configuration, the above-described calculation is performed based on the time of the hammer 2 passing through the two optical sensors SE1 and SE2, thereby obtaining the sensor of each keyboard number. The distance dxE can be measured. Then, the position of the optical sensors SE1 and SE2 can be finely adjusted while confirming the sensor distance dxE recorded in the memory with an appropriate display means. For example, a standard sensor distance may be set in advance, and the optical sensors SE1 and SE2 may be moved by a difference between the standard sensor distance and the measured sensor distance dxE. As described above, not only is there no need for any complicated device, but also there is no complexity of measuring with a clearance gauge, and the sensor distance dxE
Can be measured very simply and automatically.
In particular, in the above-described embodiment, since the string contact time dtE is obtained by a simple calculation formula based on the keyboard number, there is an advantage that no special sensor is required and the calculation is greatly simplified.

Next, FIG. 6 is a diagram showing the result of measuring the sensor distance dxE using the hammer sensor position measuring device of the present invention. As shown in the figure, when the string striking speed vP differs, the measured sensor distance dxE slightly varies, but it was confirmed that there was no problem in practical use.

B. Modification of First Embodiment Next, a modification of the above embodiment will be described with reference to FIG. In this modification, the key 1 of each keyboard number is depressed twice to create a mathematical expression equivalent to Equations 1 to 3, thereby erasing the string contact time dtE and calculating the sensor distance dxE. Features. In FIG. 3, the broken line indicates the trajectory of the hammer 2 due to the second key press. The hammer that has left the rest position xR by depressing the key first passes through the optical sensor SE1 at time tPM1 ', and then at time tPM1'.
After passing through the optical sensor SE2 at 2 ', the striking of the string 4 is started at time tPE'. Then, the hammer 2 that touches the string 4 during the string contact time dtE and leaves the string striking position xE at the string separation time tNE ′ passes through the optical sensor SE2 again at the time xNM2 ′, and passes the optical sensor SE1 at the time xNM1 ′. pass.

Here, the string striking velocity vP 'and the string releasing velocity v
N ′ can be represented by Equations 6 and 7, respectively.

(Equation 6)

[0039]

(Equation 7)

The string release time tNE 'and the string strike time tP
Since the difference from E ′ is the tangling time dtE, the following equation 8 holds.

(Equation 8) Therefore, the sensor distance dxE is calculated by using the equations (6) to (8) and the equations (1) to (3) to tPE, tNE, tPE ′, and tN.
By eliminating E ′ and dtE, it can be obtained by the following equation 9.

[0041]

(Equation 9)

In this modification, the sensor distance dxE
The performance data used for the measurement of the keyboard number # 1
From the key 1 to the key 1 of the last keyboard number (# 88). In this case, the first and second key press speeds vP, vP '
The key velocity of each event data is set such that the key release speeds vN and vN ′ are different from each other. In the position measuring device of the hammer sensor configured as described above, not only the same effect as in the above-described embodiment can be obtained, but also a mathematical expression or a conversion table for calculating the tangent distance dtE as shown in Expression 4. There is an advantage that it is not necessary to prepare such a device.

C. 2. Second Embodiment (A) Configuration of Second Embodiment Next, a second embodiment of the present invention will be described. The second embodiment is an example in which the present invention is applied to a performance data correction device. The second embodiment is different from the first embodiment in that a sensor distance dxE measured by the first embodiment or a modification thereof is used. Based on this, the string information of the automatic piano is corrected. Therefore, for the sake of simplicity, the configuration of the second embodiment will be described with reference to FIGS. 1 and 2 showing the first embodiment.

As described above, in the performance recording of the automatic piano, the time tPM2 at which the hammer passes through the optical sensor SE2 closer to the string 4 is recorded as the stringing time, but the hammer at the time of starting to strike the string 4 is recorded. Position 2 (string striking position) xE
Are located closer to the string 4 than the optical sensor SE2. Therefore, after the time tPM2, the hammer 2 moves to the sensor distance d.
After moving xE, the string reaches the string striking position xE. That is, the hammer 2 moves the stringing speed v from the rest position xR to the stringing position xE.
When it is assumed that the hammer 2 performs a constant speed motion at P, the time dxE / vP from the time tPM2 when the hammer 2 has passed the optical sensor SE2.
The actual striking will take place later. Therefore, if the stringing time detected as described above is delayed by the time dxE / vP, the time tPE at which the hammer 2 reaches the string 4 is recorded as the stringing time.

Therefore, in this embodiment,
Is recorded as the string striking time. Where dxE (k) in Equation 10 is the sensor distance at each keyboard number #k.
Required by

(Equation 10)

The calculation of the above equation (10) is performed by the post-detection processing unit 31. Further, the post-detection processing unit 31 performs normalization processing on various other information supplied from the performance detection unit 30 and then supplies the information as performance information to an external recording medium. Here, the normalization process is a process for absorbing individual differences between pianos. That is, the stringing speed, the stringing time, the key release speed, the key release time, and the like are the position of the sensor in each piano,
Since it has an inherent tendency due to a structural difference or a mechanical error, it is a process for assuming a standard piano and converting it into a striking speed, a striking time, and the like in the piano.

(B) Operation of the Second Embodiment Next, the operation of recording a performance by an automatic piano using the performance data correction device of the second embodiment will be described. First, when a performance is performed by a player, a performance detection unit 30
Detects the string striking speed and the string striking time based on the output signals of the optical sensors SE1 and SE2.
The key release time and the key release speed are detected based on the output signal of. These pieces of information are normalized by the post-detection processing unit 31, and are recorded as performance data on a recording medium such as a floppy disk. Further, at the time of the normalization processing, the post-detection processing unit 31 corrects the string striking time using the above equation (10). Thus, the striking time of the recorded performance data is
The time is delayed by a time corresponding to the sensor distance dxE from the time detected by the optical sensor SE2.

Therefore, when the recorded performance data is reproduced, the strings are struck at the time when the hammer 2 will actually strike the strings 2, so that the mounting positions of the optical sensors SE1 and SE2 vary depending on the keyboard numbers. Even if you do, you can faithfully reproduce the performance. Further, the sensors SE1, S
Since the mounting accuracy of E2 can be roughly approximated, adjustment at the factory can be easily performed. further,
Even when the model of the automatic piano that records the performance is different from the model of the automatic piano that reproduces the performance, the stringing time is corrected as described above, so that there is no inconvenience that the performance differs depending on the model.

D. Modification of Second Embodiment Next, a modification of the second embodiment will be described with reference to FIGS. Action 3 when a key is pressed
As a result, the hammer 2 is rotated, but the hammer 2 is separated from the action 3 during the rotation and moves freely. Therefore, in this modification, the string striking time and the string striking speed are corrected in consideration of the fact that the hammer 2 is decelerated by the gravitational acceleration before reaching the string 2.

As shown in FIG. 7, the trajectory of the hammer 2 passes through the optical sensor SE1 at time tPM1 and moves at time tp
Assume a parabolic trajectory passing through the optical sensor SE2 at M2. That is, it is estimated that the trajectory of the hammer 2 ends the straight trajectory before the time tPM1, and then becomes the parabolic trajectory. For comparison, a straight trajectory passing through the above two points and reaching the string striking position at time tPE is assumed. Here, the intersection of t = (tPM1 + tPM2) / 2 and the parabolic trajectory is defined as the origin O of the x · t orthogonal coordinates. Also, vp is set to t
Defined as the average speed between PM1 and tPM2, this is equal to the tangential speed at the origin O. In this case, the string striking position xE
Is a parabolic trajectory whose speed decreases, and this parabolic trajectory can be represented by the following equation (11).

[Equation 11]

Next, assuming that the point at which the parabolic trajectory reaches the string striking position xE is D, the coordinates of the point D in x · t orthogonal coordinates will be considered. Assuming that the t coordinate of the point D is dtPE as shown in FIG. 7, the x coordinate of the point D can be represented by the following equation (12).

(Equation 12)

Here, assuming that the time when the parabolic trajectory reaches the string striking position xE (hereinafter referred to as corrected string striking time) is tPE ', dtPE is (tPE'-(tPM1 + tPM2) /
Since this can be expressed as 2), when this is substituted into Expression 12, Expression 13 is obtained.

(Equation 13)

Since equation (13) is a quadratic equation for tPE ′, solving this equation gives tPE ′ as follows:
Can be determined by: In Equation 14, “sqrt” indicates a square root. In addition, two large and small roots are obtained as the value of tPE '. Since it is clear from FIG. 7 that tPE' is the smaller root, Equation 14 shows the smaller root. Further, since the speed vP of the hammer 2 in the constant velocity orbit is small, the parabolic orbit is changed to the stringing position x.
It is also assumed that E does not reach. In this case, Equation 14
Since the square root of is negative, the square root term is calculated as 0.

[Equation 14] The tPE in the last line of Expression 14 is a string striking time when the trajectory of the hammer 2 is regarded as a straight trajectory, and can be obtained by Expression 10 described above. As described above, the corrected stringing time tPE ′ is obtained by further correcting the stringing time tPE obtained by regarding the trajectory of the hammer as a linear trajectory.

Next, the speed v of the hammer 2 can be expressed by the following equation (15).

(Equation 15) Here, assuming that the velocity at the string striking position xE (hereinafter, this velocity is referred to as a corrected string striking velocity) v is vPE, t is dtP
In the case of E, v becomes vPE.
Can be obtained by substituting into

[0055]

(Equation 16)

Next, the operation of this modification will be described with reference to FIG. When a player depresses a key, the performance detector 30 detects the stringing speed vP and the stringing time tPM2 based on the output signals of the optical sensors SE1 and SE2, and a stringing event as performance data is generated. I do. Next, the post-detection processing unit 31 obtains a corrected string striking time tPE ′ according to Equation 14 (Step S11). In this case, dxE (sensor distance) in Expression 14 is obtained by Expression 5 or Expression 9. Next, the post-detection processing unit 31 obtains the corrected stringing speed vPE from Expression 16 (step S1).
2), the process proceeds to step S13 to delay the output of the performance data to the recording medium.

That is, in the automatic performance piano to which this modification is applied, in order to output the performance data in real time, the output of the performance data is delayed by the difference between the string striking time tPM2 and the corrected string striking time tPE '. The output performance data includes, in addition to the corrected stringing time tPE ′ and the corrected stringing speed vPE determined as described above, a key release time and a key release detected based on the output signal of the key sensor 25. Speed is included. These pieces of information are stored in the post-detection processing unit 31.
Are normalized.

According to this modified example, the same operations and effects as those of the above-described second embodiment can be obtained, and the following advantages can be obtained. That is, the hammer 2 has the optical sensor SE.
In the method in which the time of passing the string 2 is the stringing time, the detected stringing time is before the actual stringing time, so that the weaker the keystroke, the smaller the detected stringing time and the actual stringing time. The time difference from the timing of the strings became large, and the recording of the performance was inaccurate.
Since the string striking time is corrected by regarding the trajectory from the middle of the rotation as a parabola, the string striking time is recorded with a delay corresponding to the weak striking, so that the performance can be accurately recorded. Also, when the time difference between the detected stringing time and the actual stringing timing increases, the deceleration and the degree of the detected stringing speed also increase, so that the recording of the stringing speed was also inaccurate. In this modification, such a disadvantage is solved.

E. Other Modifications (1) In the second embodiment, the string striking time and the string striking speed are corrected when the performance is recorded. However, it is possible to make corrections when the performance is reproduced. For example, the time calculated by the time passed through the optical sensor SE2 as the string striking time and the time calculated by the time passed through the optical sensors SE1 and SE2 as the string striking speed are recorded, and the above-described correction is performed when the recorded performance data is reproduced. You can do so.

(2) In the second embodiment and its modifications, the performance data can be normalized according to the mass of the hammer. That is, even if the strings are struck at the same key number and at the same string striking speed, if the mass of the hammer differs according to the model, the energy at which the hammer strides differs from model to model. Therefore, when the performance is reproduced with the same performance data, the volume differs depending on the model. Therefore, even when the model is different, the hammering speed can be corrected and recorded so that the energy when the hammer hits the string is the same.

First, assuming that the average mass of the hammer of the reference model is m0, the energy E when the hammer strikes a string at the string striking speed vP 'can be expressed by the following equation (17).

[Equation 17] Further, assuming that a code indicating a certain model is n and the average mass of the hammer of the model is m (n), the hammer has a stringing speed v
Assuming that the energy when the string is struck at P is equal to the energy E shown in Expression 17, the following Expression 18 is established.
Equation 19 below can be obtained.

[0062]

(Equation 18)

[0063]

[Equation 19]

Equation 19 shows that the stringing speed is standardized (normalized) according to the average mass of the hammer of the model when the performance is recorded on the model. For example,
When you record your performance on a piano with a small average hammer mass,
The string striking speed is recorded after being corrected to a small value according to Expression 19. Then, when the performance data is reproduced on a model having a standard average hammer mass, a performance with a reduced volume is performed.
That is, reproduction is performed at a volume close to the volume at the time of recording the performance.

(3) Generally, the mass of the hammer is adjusted so as to decrease as the keyboard number increases, and the hammer of the keyboard number # 40 (# 60 in the case of the MIDI sound source) is the average mass of all the hammers. have. Therefore, even when the string striking speed is the same, the energy at the time of striking differs depending on the keyboard number, and the volume of the sound generated by striking differs. Here, if the hammer mass is larger than the average, the stringing speed is increased, and if the hammer mass is smaller than the average, the stringing speed is reduced so that the stringing speed is reduced, and the recording is performed. It is convenient for using data. For example,
When playing performance data with instruments with all hammers of the same mass, the performance data corrected as above is used to reflect the weight of the hammer at the time of recording in the string striking speed and faithfully reproduce the performance. Can be reproduced. Therefore, an example in which the string striking speed corrected in the modification of the second embodiment is further corrected by each hammer mass will be described.

Assuming that the mass of the hammer of keyboard number # 40 is m40, the energy E when the hammer strikes a string at the string velocity vP 'can be expressed by the following equation (20).

(Equation 20) Further, the mass m of the hammer of the keyboard symbol k can be represented by the following Expression 21. In Equation 21, α is a fixed value.

[0067]

(Equation 21)

Next, the hammer of the keyboard symbol k changes the stringing speed vP.
Assuming that the energy at the time of striking the string is equal to the energy E shown in Expression 20, Expression 22 is established, and Expression 23 can be obtained from Expression 22.

(Equation 22)

[0069]

(Equation 23)

By correcting the string striking speed by equation 23,
The stringing speed when all the hammer masses are averaged is recorded, and the stringing speed is standardized. When playing back the performance data including the standardized striking speed, the key velocity can be corrected according to the mass of each hammer of the instrument used for playback, as well as playing it as it is. You can also. For example, the actual measured value ma of the mass of each hammer is recorded in an appropriate control means (for example, the reproduction preprocessing unit 10) of the automatic piano, and the key velocity vP of the performance data is corrected by the following equation (24). Then, the key depression is controlled by the key velocity vP ′ obtained by Expression 24.

(Equation 24) The string striking time obtained in the modification of the second embodiment can also be recorded in consideration of the case where the performance data is reproduced with the same musical instrument as that used at the time of recording.

(4) The present invention can be applied to a so-called silence performance piano. The silence performance piano is configured to bounce a hammer that rotates by pressing a key in front of a string, and to generate music electronically based on the detected performance data. By correcting the string striking time and the string striking speed in the detected performance data as described above, it is possible to perform a performance similar to an acoustic piano.

(5) In the first embodiment, the key 1 is driven by the performance data to automatically measure the sensor distance. However, the key may be depressed by a person. The estimation of the sensor distance may be performed during the operation.

(6) Connect the hammer 2 to the optical sensors SE1 and SE2.
The detection is not limited to the configuration described above, and the catcher 2a may be detected.

(7) The optical sensors SE1 and SE2 are not limited to those integrally formed as in the above embodiment, but may be separated from each other. In the first embodiment described above, the string contact time is changed only by the keyboard number. However, the string contact time is further determined in accordance with the keyboard number and the string striking speed, and the sensor position is determined by the string contact time. Is calculated, more accurate detection becomes possible. Also,
In the above-described embodiment, the string arriving time is taken into consideration. However, the string arriving time may not be taken into account in order to speed up the processing. Furthermore, in the above-described embodiment, the string striking speed and the string releasing speed are used, but both may be regarded as constant speeds. Here, the calculation of the sensor distance can be simplified in the case where the string contact time is not considered, the string striking speed and the string releasing speed are regarded as being equal, and the linear approximation is performed. That is, since the hammer moves by 2 · dxE at the stringing speed vP during the period from tPM2 to tNM2, the sensor distance dxE can be calculated as dxE = (tNM2−tPM2) · vP, which simplifies the processing. Speeding up. Further, it may be possible to switch between linear approximation and parabolic approximation according to the string striking speed. Since a weak hit has a large influence of gravity, it is parabolic approximation. In the case of a strong hit, the calculation is easy by linear approximation, so that the speed can be increased as compared with the case of always using parabolic approximation. In addition, the effects of gravity also vary with the type of piano. That is, in an upright piano, the hammer rotates in the left-right direction, so that it is not much affected by gravity. In a grand piano, the hammer rotates in the up-down direction, so that it is affected by gravity. Therefore, a straight line approximation may be used for an upright piano, and a parabolic approximation may be used for a grand piano.

(8) In the above-described embodiment, the length (path) along the turning trajectory of the hammer 2 from the position of the sensor SE2 (the second position) to the string is used as the sensor distance to be detected. Was targeted, but instead, for example,
A linear distance or another distance between the position of the sensor SE2 and the string may be defined. In short, the position of the sensor SE2 (second
The position information may be information corresponding to the distance between the string) and the string.

(9) The transit time between the sensors SE1 and SE2 is, for example, from when the hammer passes through the sensor SE1 to when it passes through SE2 (or from when it passes through SE2 to when it passes through SE1). During this time, a counter that performs counting may be prepared, and the count value of this counter may be used as the passage time. In the embodiment described above,
The sensor position was obtained by calculation using the passing times of the sensors SE1 and SE2. Instead, a table storing the correspondence between the time difference between the passing times and the sensor position (the distance between the sensor and the string) was used. Alternatively, the position of the sensor corresponding to the time difference may be read from the table. Further, a table storing the relationship between the count value of the above-described counter and the sensor position may be prepared, and the sensor position corresponding to the count value may be read.

[0077]

As described above, according to the present invention, information corresponding to the distance between the hammer sensor and the string is obtained based on the time difference when the hammer mechanism passes between the first position and the second position. In addition, the position of the sensor can be measured quickly, accurately and automatically, and the manufacturing cost can be minimized (claim 1). Further, if the sensor position is obtained based on the time difference between the detection times and the string contact time during which the hammer mechanism is in contact with the string, the sensor position can be easily determined if the string contact time is known. Can be determined (claim 2). Further, if the sensor position is obtained based on the respective time differences obtained by a plurality of key presses, the sensor position can be measured even if the string contact time is unknown (claim 3). In addition, if the speed of the hammer mechanism is obtained from the time difference between the detection times and the sensor position is obtained with reference to this speed, the sensor position can be obtained very accurately (claim 4). If the stringing time is calculated based on the sensor position and the hammer speed obtained as described above, an extremely accurate value can be obtained (claim 5). The accuracy can be further improved by correcting at least one of the string striking time and the string striking speed in accordance with the deceleration trajectory of the hammer mechanism toward the string striking (claim 6).

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of the present invention.

FIG. 2 is a diagram showing a hammer trajectory of the first embodiment.

FIG. 3 is a diagram showing a hammer trajectory in a modification of the first embodiment.

FIG. 4 is a diagram showing a relationship between a keyboard number and a string contact time.

FIG. 5 is a flowchart showing the operation of the first embodiment.

FIG. 6 is a diagram showing a relationship between a string striking speed and a measured sensor distance.

FIG. 7 is a diagram showing a hammer trajectory in a modified example of the second embodiment.

FIG. 8 is a flowchart illustrating an operation of a modification of the second embodiment.

[Explanation of symbols]

2 ... hammer (hammer mechanism), 4 ... string, 31 ... post-detection processing unit (arithmetic means), dtE ... string contact time, dxE ...
... sensor distance, tPE ... string striking time, tNE ... string unwinding time, xPM1 ... first position, xPM2 ... second position.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Taro Kawabata 10-1, Nakazawa-cho, Hamamatsu-shi, Shizuoka Yamaha Co., Ltd. (72) Inventor Rei Furukawa 10-1-1, Nakazawa-cho, Hamamatsu-shi, Shizuoka Pref. 72) Inventor Takashi Tamaki 10-1 Nakazawacho, Hamamatsu City, Shizuoka Prefecture Inside Yamaha Corporation

Claims (6)

[Claims] 1. A sensor for detecting passage of a hammer mechanism which is rotated by key depression at a first position and a second position closer to a string than the first position, and detection of the sensor at first and second positions. A position measuring device for a hammer sensor, comprising: sensor distance information generating means for generating sensor position information corresponding to a distance between the second position and the string based on a time difference between times. 2. The apparatus according to claim 1, wherein the sensor distance information generating unit determines a distance between the second position and the string based on a time difference between the detection times and a string contact time when the hammer mechanism is in contact with the string. The position measuring device for a hammer sensor according to claim 1, wherein information corresponding to the following is generated. 3. The method according to claim 1, wherein the sensor distance information generating means generates information corresponding to a distance between the second position and the string based on the time differences obtained by a plurality of key presses. The position measuring device for a hammer sensor according to claim 1. 4. The sensor distance information generating means obtains a speed of the hammer mechanism from a time difference between the detection times, and also refers to this speed to obtain information corresponding to a distance between the second position and a string. The position measuring device for a hammer sensor according to claim 1, wherein the position is generated. 5. A sensor for detecting passage of a hammer mechanism that is rotated by key depression at a first position and a second position closer to a string than the first position, and detection of the sensor at first and second positions. A sensor distance information generating means for generating sensor position information corresponding to a distance between the second position and the string based on a time difference between times; a speed calculation for obtaining a hammer speed of the hammer mechanism based on the time difference A performance data correction apparatus, comprising: means for calculating a stringing start time of the hammer mechanism based on the speed obtained by the speed calculation means and the sensor position information. 6. The performance data according to claim 5, wherein the calculating means corrects at least one of the stringing time and the stringing speed in accordance with the deceleration trajectory of the hammer mechanism toward the stringing. Correction device.