JPH11282538A - Servo device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To quickly reduce deviation of position with a fast loop gain when the comparatively large deviation of position occurs due to the disturbance, etc., and to improve the follow-up accuracy of a servo device by maximizing the gain at a point that is previously designated as the difference between a position command and the position detection output of a detection means. SOLUTION: The detection means (an encoder 7 and a differetiator 8) detect the position and speed of a servo motor 6. A position arithmetic means (a position control part 2) generates a speed command 12 based on the difference 11 between a position command 9 inputted from the outside and the position detection output 10 of the detection means. A speed arithmetic means (a speed control part 3) generates a torque command 15 by multiplying the difference 14 between the command 9 and the speed detection output 10 of the detection means by the prescribed gain. A current drive means (a power amplifier circuit 5) supplies a current to the motor 6 based on the command 15. Then the gain is maximized at a point where the deviation of position, i.e., the difference 14 is equal to the value that is previously designated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a servo device for driving a machine tool or the like by a servo motor.

[0002]

FIG. 13 is a control block diagram of a conventional servo device. In the figure, reference numeral 1 denotes a position command generation unit, and 2 denotes a position calculation unit, for example, a position control unit. Reference numeral 3 denotes a speed calculation unit, for example, a speed control unit. 4 is a current control unit, 5
Is a current driving means, for example, a power amplifier circuit. Reference numeral 6 denotes a motor, for example, a servo motor. 7 is an encoder for detecting the rotational position of the servo motor 6, and 8 is an encoder 7
Is a differentiating means for differentiating the position detection output to calculate the speed. The encoder 7 and the differentiator 8 constitute a detector. Reference numeral 9 denotes a position command output from the position command generation unit 1, 10 denotes a position feedback signal output from the encoder 7, 11 denotes a position deviation signal, and 12 denotes a position control unit 2.
Is a speed feedback signal output from the differentiating means 8, 14 is a speed deviation signal which is a difference between the speed command 12 and the speed detection signal, and 15 is a torque command output from the speed control unit 3. , 16 are current feedback signals indicating the current flowing through the servo motor 6.
This servo device is configured to rotate the servomotor 6 so that a position feedback signal 10 of the servomotor 6 detected by the encoder 7 follows a position command signal 9 output by the position command generator 1. . Also, in order to perform this operation stably at high speed, the position control unit 2 generates a speed command 12 based on a deviation signal 11 between the position command signal 9 and the position feedback signal 10, and generates the speed command 12 based on the position feedback signal 10 by the differentiating means 8. The speed control unit 3 controls the current command 15 to the servo motor 6 so that the speed feedback signal 13 to follow follows the speed command 12.
Is output. Further, the current control unit 4 and the power amplification unit 5 allow the current to flow through the servo motor 6 so that the current feedback 16 indicating the value of the current flowing through the servo motor 6 follows the current command 15. That is, the speed control loop is a minor loop of the position control loop, and a current loop is further formed inside the speed control loop. In a servo control device, PI control is generally used as a control method.
Control and model adaptive control are also used. Regardless of which control method is used, the gain in each control loop is generally fixed in advance by adjustment or tuning in the conventional device. There are devices that change the gain in the control loop in a non-linear manner in real time.However, since it is configured so that it does not simply exceed the preset upper limit, the speed loop gain is always set from the viewpoint of required accuracy. Is set too high and the operation becomes unstable.

[0003]

In the conventional servo device, the delay during movement is not important, as in the case of high-speed positioning, and even when the delay becomes a problem when approaching the positioning target position, the servo is not required. Since the gain in the loop is fixed or is configured to simply limit nonlinearly so that it does not exceed the preset upper limit, the speed loop gain is always high from the viewpoint of required accuracy. There is a problem that resonance and vibration of the mechanical system are easily induced during high-speed movement. In addition, since the resonance frequency of the mechanical system usually exceeds the responsive frequency of the control loop, when the resonance of the mechanical system is induced, it may become impossible to control and the power must be turned off. There was a problem that operation could not be obtained.

[0004] There is also a problem that a sufficient resistance to disturbance after positioning or the like cannot be obtained.

In a large machine tool or a mechanical device using a linear servomotor, one axis may not be driven by one motor, so that one axis may be driven by a plurality of motors. In such a case, since it is necessary to drive a plurality of motors synchronously, the same command is given to the drive units of the respective motors, and each of the drive units is driven based on the position detection output from the position detector of the own motor. Although individual position control was performed, if the gain was increased to improve positioning accuracy, interference between the motors due to the mismatch in the phase of the servo response between the axes caused the vibration phenomenon, etc. There was a problem.

[0006]

A servo device according to the present invention comprises a motor, a detecting means for detecting the position and speed of the motor, and a difference between a position command inputted from outside and a position detection output of the detecting means. A position calculating means for generating a speed command, a speed calculating means for generating a torque command by multiplying a difference between the speed command and the speed detection output of the detecting means by a predetermined gain, and a current drive for flowing a current to the motor based on the torque command. And a means for maximizing the gain when the position deviation, which is the difference between the position command and the position detection output of the detecting means, is a magnitude designated in advance.

[0007] In addition, there is an ideal position loop model, and the gain is maximized when the position deviation, which is the difference between the current position signal output from the ideal position loop model and the position detection output of the detection means, is a predetermined magnitude. It is to become.

A motor, detection means for detecting the position and speed of the motor, and position calculation for generating a speed command based on a position deviation which is a difference between a position command input from the outside and a position detection output of the detection means. Means, a speed calculating means for generating a torque command by multiplying a speed deviation which is a difference between the speed command and the speed detection output of the detecting means by a predetermined gain, and a current driving means for flowing a current to the motor based on the torque command, It has first and second servo devices, respectively, and a position deviation, which is a difference between a position detection output of the detection means of the first servo device and a position detection output of the detection means of the second servo device, is at a position designated in advance. The gain is maximized.

Further, there is provided a position deviation smoothing means for inputting a position deviation and outputting a signal in which a falling edge of a signal waveform indicating the position deviation is gentle, and the gain is maximized when the signal has a predetermined magnitude. It is to become.

In addition, a signal in which the position deviation is input and the signal waveform indicating the position deviation is microscopically gentle and the signal whose magnitude changes in accordance with the fluctuation frequency of the position deviation is macroscopically. A position deviation smoothing means for outputting the signal is provided, and the gain is maximized when the signal has a predetermined magnitude.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 of the Invention FIG. 1 is a block diagram of a servo device according to Embodiment 1 of the present invention. FIG. 1 is the same as FIG. 13 showing the conventional device except that the position deviation signal 11 is input to the speed control unit 3. In the first embodiment of the present invention, the speed control unit 3
Outputs the current command 15 obtained by the following equation. I_CMD = Kv_p1 × ev + KvI × (evI) (1) Kv_p1 = Kv_c + α × | ep | / (1 + κ × ep × ep) (2) where I_CMD is the value of the current command 15 and Kv_p1 is the speed The loop gain, ev, is the magnitude of the speed deviation signal 14, KvI
Is the value of the speed loop integration gain, and evI is the speed deviation signal 1
4, Kv_c is the minimum value of the speed loop gain, ep
Is the magnitude of the position deviation signal 11, and α and κ are constants that give the peak value of the velocity loop gain and the magnitude of the position deviation signal 11 when the peak value is reached. Note that Kv_
p1 × ev corresponds to a proportional term in PI control, and KvI
× (evI) corresponds to an integral term in PI control.

FIG. 2 is a diagram showing the relationship between the magnitude ep of the position deviation signal 11 and the speed loop gain Kv_p1 represented by the equation (2). As shown in the figure, the value of | ep | when the speed loop gain Kv_p1 is maximized is 1 /
κ, and the maximum value of the speed loop gain Kv_p1 is α /
(2κ). Note that α / 2k and 1 / k are
Since it can be set arbitrarily by α and k, for example, α / 2k
May be set to the maximum value of the speed loop gain limited by the current loop, and 1 / k may be set to the value of the position deviation when the speed loop gain is maximized.

According to the first embodiment, when setting at the time of stop is a problem as in the case of high-speed positioning,
Since the speed response in the region where the position deviation during high-speed movement is extremely large does not cause much problem, the gain should be lowered so as not to induce mechanical resonance, and if a relatively large position deviation occurs due to disturbance or the like, immediately Increase the speed loop gain within the range limited by the response of the current loop in response to the position deviation to suppress the increase in the position deviation, and reduce the speed loop gain when the position deviation is extremely small. Accordingly, induction of magnetic noise and mechanical vibration caused by increasing the servo gain at the time of stopping or the like is suppressed. Further, the peak value of the speed loop gain and the value of the position deviation when the peak value is reached can be arbitrarily set in advance. Further, since the change of the gain is a change by a simple function that does not change suddenly, the gain can be easily and stably set, the calculation of the torque in the speed control unit 3 can be performed quickly, and a high-speed response can be achieved.

Embodiment 2 of the Invention FIG. 3 is a block diagram of a servo device according to Embodiment 2 of the present invention. In the figure, reference numeral 38 denotes a position deviation smoothing means, for example, a position deviation smoothing circuit. FIG. 3 is the same as FIG. 1 except that the position deviation signal 11 is input to the speed control unit 3 via the position deviation smoothing circuit 38. Next, an internal circuit of the position deviation smoothing circuit 38 will be described. In the position deviation smoothing circuit 38, reference numeral 22 denotes an absolute value generation unit that makes the position deviation 11 an absolute value;
28 is an absolute value signal which is an output signal from the absolute value generating unit 22, 23 is a differentiator for differentiating the absolute value signal 28, 29 is a differential signal which is an output signal from the differentiator 23, and 24 is a sign of the differential signal 29 , 30 is a sign signal which is an output signal from the signal generator 24, and 32 is an ep which is an output signal of the position deviation smoothing circuit 38.
The s1 signal 25 is a determination unit. When the code signal 30 is 1, the determination unit 25 compares the eps1 signal 32 with the absolute value signal 28, and compares the eps1 signal 32 with the absolute value signal 28.
1 is output if the value is smaller than 0, and 0 if the value is larger.
Is output. 31 is a determination result signal which is an output signal from the determination unit 25, 26 is a smoothing gain unit for multiplying by a smoothing gain,
27 is a memory unit for storing the previous value.

In the second embodiment, in the servo device shown in FIG. 3, the speed controller 3 obtains and outputs a current command 15 according to the following equation. I_CMD = Kv_p2 × ev + KvI × (evI) (3) Kv_p2 = Kv_c + α × | eps1 | / (1 + κ ′ × eps1 × eps1) (4) where Kv_p2 is a speed loop gain and eps1 is a position. The magnitudes α and κ of the position deviation smoothing signal output from the deviation smoothing circuit 38 are constants that give the peak value of the velocity loop gain and the magnitude of the position error smoothing signal 33 when the peak value is reached.

FIG. 4 shows a position deviation signal 11 and an absolute value signal 2
8, differential signal 29, sign signal 30, decision result signal 31,
FIG. 4 is a signal waveform diagram showing a relationship of an eps1 signal 32. As shown in the drawing, eps1 whose fall is smoothed without delaying its rise based on the position error signal ep.
The signal 32 is generated, and the speed loop gain Kv_p2 is obtained by the equation (4) based on the eps1 signal 32. By obtaining in this manner, the speed loop gain is set based on the smoothed signal whose fall is smoothed without delaying the rise of the position deviation signal. Is suppressed, stable control is performed, and when a position deviation occurs, the speed loop gain can be changed immediately in response to the position deviation.

Embodiment 3 of the Invention FIG. 5 is a block diagram of a servo device according to Embodiment 3 of the present invention. In the figure, reference numeral 39 denotes position deviation smoothing means, for example, a position deviation smoothing circuit. 5 is the same as FIG. 3 except that the position deviation smoothing circuit 38 is replaced with a position deviation smoothing circuit 39. Next, the position deviation smoothing circuit 39 will be described. In the position deviation smoothing circuit 39, 22 is the position deviation signal 11
An absolute value generation unit that takes the absolute value of
, 23 is a differentiator for differentiating the absolute value signal 28, 29 is a differential signal output from the differentiator 23, 24 is a signal generator that outputs 1 or −1 depending on the sign of the differential signal 29. , 30 are code signals output from the signal generator 24, and 25 is a determination unit. Reference numeral 40 denotes a counter for counting the number of the code signals 30 within a predetermined time period, reference numeral 41 denotes a count value signal output from the counter 40, and reference numeral 42 denotes a signal obtained by multiplying the count value 41 by the signal of the absolute value signal 28. is there. The above-described determination unit 25 outputs the signal 42
Is compared with the position deviation smoothed signal 33. If the position deviation smoothed signal 33 is smaller than the signal 42, 1 is output. 31 is a determination result signal output from the determination unit 25, 26 is a smoothing gain unit for multiplying a smoothing gain, 2
Reference numeral 7 denotes a memory unit for storing a previous value.

In the third embodiment, the speed control unit 3 calculates and outputs the current command 15 according to the following equation (6). I_CMD = Kv_p3 × ev + KvI × (evI) (5) Kv_p3 = Kv_c + α × | eps2 | / (1 + κ × eps2 × eps2) (6) where Kv_p3 is the gain of the velocity loop and esp2 is the position deviation. The magnitudes α and κ of the position deviation smoothing signal 33 output from the smoothing circuit 39 are constants that give the peak value of the velocity loop gain and the magnitude of the position error smoothing signal 33 when the peak value is reached.

FIG. 6 shows a position deviation signal 11 and an absolute value signal 2
8, differential signal 29, sign signal 30, decision result signal 31,
It is a signal waveform diagram which shows the relationship of the signal 33 (= eps2). As shown in the figure, the eps2 signal 33 whose fall is smoothed without delaying its rise based on the position error signal 11 (= ep), and the magnitude of the output signal changes according to the fluctuation frequency of the position error signal ep. Generate this e
From the ps2 signal 33 and equation (6), the velocity loop gain Kv
Since _p3 is obtained, in addition to the effect of the second embodiment, in the case of a high frequency where the fluctuation frequency matches the mechanical resonance frequency, the speed loop gain is suppressed to a small value, and the operation can be performed more stably.

Embodiment 4 of the Invention FIG. 7 is a block diagram of a servo device according to Embodiment 4 of the present invention. In FIG. 1, the position deviation signal 11 (= ep) is input to the speed control unit 3 as one input signal, but in FIG. Signal 35 and actual position feedback 10
And a deviation signal 36 (= epm) indicating the deviation from the above. This ideal position loop model 34 has the same servo configuration as that of FIG. 1 except that the functions of each component including a motor, a mechanical system, a load, and the like are given by mathematical expressions. Or a function that does not depend on the actual mechanical system or the state of the load. As a result, the speed loop gain changes only when a deviation occurs with respect to the output of the ideal position loop model 34, and the speed loop gain hardly changes with respect to a normal change in the position deviation occurring during operation. If the deviation occurs due to the disturbance or the delay of the speed loop without changing, the speed loop gain can be changed correspondingly.

Embodiment 5 of the Invention FIG. 8 is a block diagram of a servo device according to Embodiment 5 of the present invention. In FIG. 3, the position deviation signal 11 (= ep) is input to the position deviation smoothing circuit (1) 38. In FIG. 8, however, the ideal position signal 35 output from the ideal position A deviation signal 36 (= epm) indicating a deviation from the position feedback 10 is input. As a result, the speed loop gain changes only when a deviation occurs with respect to the output of the ideal position loop model 34. Even if the normal position deviation signal 11 generated during operation changes, the speed loop gain changes. The gain hardly changes, and if a deviation occurs due to disturbance or a delay in the speed loop, the speed loop gain can be changed immediately in response to the deviation.

Embodiment 6 of the Invention FIG. 9 is a block diagram of a servo device according to Embodiment 6 of the present invention. In FIG. 5, the position deviation signal 11 (= ep) is input to the position deviation smoothing circuit (2) 39, but in FIG. A deviation signal 36 (= epm) indicating a deviation from the position feedback 10 is input. As a result, the speed loop gain changes only when a deviation occurs with respect to the output of the ideal position loop model 34. Even if the normal position deviation generated during operation changes, the speed loop gain hardly changes. If a deviation occurs due to a disturbance or a delay in the speed loop, the speed loop gain can be immediately changed in response to the deviation.

Embodiment 7 of the Invention FIG. 10 is a block diagram of a servo system according to Embodiment 7 of the present invention.
FIG. 10 shows a servo device that drives one axis by first and second servo motors. That is, in this servo device, one axis is driven by the first and second servo devices, which are two servo devices each having the servo motor 6, and the first and second servo devices are respectively driven. The speed controller 3 calculates and outputs the current command 15 according to the following equation. I_CMD = Kv_p4 × ev + KvI × (evI) (7) Kv_p4 = Kv_c + α × | epe | / (1 + κ × epe × epe) (8) where Kv_p4 is a speed loop gain and epe is two. The magnitudes α and κ of the position error signal 37 indicating the position error between the servomotors 6 are constants giving the peak value of the velocity loop gain and the magnitude of the position error signal 37 when the peak value is reached. . Note that the speed loop gain Kv
_p4 and the position error signal 37 (= epe) have a relationship as shown in FIG. 2 as in the first embodiment of the present invention.

According to the seventh embodiment, in a servo system in which one axis is synchronously driven by a plurality of servomotors, for example, when a heavy object moves on another axis stacked on the axis and the center of gravity changes. As a result, the speed loop response between the servo controllers does not match, and a difference occurs in the current position (for example, even if a plurality of motors are mechanically connected, for example, a torsion of the shaft occurs. When a slight difference occurs in the current position), the speed loop gain can be increased immediately within the range limited by the responsiveness of the current loop in response to the difference to suppress the increase in the difference. Further, in a region where the position deviation during the high-speed movement is extremely large, the speed loop gain is reduced, and the occurrence of mechanical resonance caused by the large speed loop gain and the occurrence of interference between servo motors can be prevented. . Also, the peak value of the speed loop gain and the value of the position error between the servomotors when the speed loop gain is at the peak value can be set in advance (however, the peak value of the speed loop gain is limited by the characteristics of the current loop. receive). In addition, since the speed loop gain is determined by a simple function, continuous and stable gain characteristics can be easily obtained.

Embodiment 8 of the Invention FIG. 11 is a block diagram of a servo device according to Embodiment 8 of the present invention. FIG. 11 shows a servo control system in which one axis is driven by two servo motors, similarly to the seventh embodiment of the present invention. One axis is driven by two servo control devices each having a servo motor. It is configured as follows. In the eighth embodiment, the position error signal 37 is smoothed by a position error smoothing circuit 38 without being directly supplied to each speed control unit 3 as a signal for controlling the speed loop gain. The speed control unit 3 of the servo control unit calculates and outputs the current command 15 according to the following equation. I_CMD = Kv_p5 × ev + KvI × (evI) (9) Kv_p5 = Kv_c + α × | epes1 | / (1 + κ × epes1 × epes1) (10) Here, Kv_p5 is a velocity loop gain, and epes1 is a position error. The magnitudes α and κ of the position error smoothing signal output from the smoothing circuit 38 are constants that give the peak value of the velocity loop gain and the magnitude of the position error smoothing signal when it reaches this peak value.

In the eighth embodiment of the present invention, the speed loop gain is set based on a smoothed signal having a signal waveform whose fall is smoothed without delaying the rise of the position error signal. And the speed loop gain can be changed immediately when a position error occurs.

Embodiment 9 of the Invention FIG. 12 is a block diagram of a servo device according to Embodiment 9 of the present invention. FIG. 12 shows a servo device that drives one axis by two servo motors, similarly to the eighth embodiment of the present invention.
One axis is driven by first and second servo devices each having a servomotor. In the ninth embodiment, the position error signal 37 is not smoothed by the position error
The speed controller 3 of each of the first and second servo devices calculates and outputs a current command 15 according to the following equation. I_CMD = Kv_p6 × ev + KvI × (evI) (11) Kv_p5 = Kv_c + α × | epes2 | / (1 + κ × epes2 × epes2) (12) where Kv_p6 is the velocity loop gain and epes2 is the position error. The magnitudes α and κ of the position error smoothing signal output from the smoothing circuit 39 are constants that give the peak value of the velocity loop gain and the magnitude of the position error smoothing signal when the peak value is reached.

According to the ninth embodiment, the fall of the position error signal is smoothed without delaying the rise, and the smoothed signal whose output value changes according to the fluctuation frequency of the position error signal is obtained. Since the speed loop gain is set based on the speed loop gain, the speed loop gain can be reduced in a case where the fluctuation frequency is a high frequency that matches the mechanical resonance frequency.

[0029]

According to the present invention, the speed loop gain is maximized when the position deviation, which is the difference between the position command and the position detection output of the detection means, is a predetermined magnitude, so that the speed loop gain becomes large due to disturbance or the like. When a relatively large position deviation occurs, the position deviation can be rapidly reduced by a high speed loop gain to improve the tracking accuracy, and in a region during high-speed movement where the position deviation is extremely large, and in a region where the position deviation is extremely small, Due to the low speed loop gain, induction of mechanical resonance and magnetic noise of the motor is suppressed, and the operation can be stabilized.

Further, the apparatus has an ideal position loop model, and the velocity loop gain is set when the position deviation, which is the difference between the current position signal output from the ideal position loop model and the position detection output of the detecting means, is a predetermined magnitude. When the position deviation is relatively large with respect to the control target position due to disturbance or the like, the position deviation can be quickly reduced by the high speed loop gain to improve the tracking accuracy with respect to the control target position. In the case where the deviation is extremely large, and in the case of the normal operation in which the position deviation is extremely small, it is possible to prevent mechanical resonance and the generation of magnetic noise of the motor by a low speed loop gain, thereby stabilizing the operation.

In a servo device in which the first and second servo devices drive one axis, the difference is the difference between the position detection output of the detection device of the first servo device and the position detection output of the detection device of the second servo device. Since the speed loop gains of the first and second servo devices are maximized when the position deviation is a predetermined size, the speed loop between the first and second servo devices due to a change in the center of gravity of the mechanical system or the like. When a relatively large position deviation occurs between the first and second servo devices due to the occurrence of a difference in response, the occurrence of disturbance, or the like, the speed loop gain of the first and second servo control devices is immediately increased to increase the position deviation. To reduce the occurrence of interference between motors, and to reduce mechanical resonance due to the low speed loop gain when the position deviation is extremely large and in normal operation when the position deviation is extremely small. It is possible to prevent the occurrence of magnetic noise of the motor, there is an effect capable of stabilizing the operation.

Further, there is provided a position deviation smoothing means for inputting the position deviation and outputting a signal in which the signal waveform indicating the position deviation has a gentle fall, and the gain becomes maximum when this signal has a predetermined magnitude. As a result, the fluctuation of the speed loop gain is suppressed, and the control can be more stabilized.

Also, a signal in which the position deviation is input and the signal waveform showing the position deviation is microscopically gentle and the magnitude thereof changes macroscopically in accordance with the fluctuation frequency of the position deviation. The output position deviation smoothing means is provided so that the gain becomes maximum when this signal has a predetermined magnitude, so that in the case of a high frequency which is difficult to control in the control loop, the speed loop gain becomes small and mechanical resonance or the like is caused. Unstable operation can be prevented, and control can be further stabilized.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a servo device according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a speed loop gain in the servo device shown in FIG.

FIG. 3 is a block diagram showing a servo device according to a second embodiment of the present invention.

FIG. 4 is an explanatory diagram showing signal processing contents of a position deviation smoothing circuit in the servo device shown in FIG. 3;

FIG. 5 is a block diagram showing a servo device according to a third embodiment of the present invention.

6 is an explanatory diagram showing signal processing contents of a position deviation smoothing circuit in the servo device shown in FIG.

FIG. 7 is a block diagram showing a servo device according to a fourth embodiment of the present invention.

FIG. 8 is a block diagram showing a servo device according to a fifth embodiment of the present invention.

FIG. 9 is a block diagram showing a servo device according to a sixth embodiment of the present invention.

FIG. 10 is a block diagram showing a servo device according to a seventh embodiment of the present invention.

FIG. 11 is a block diagram showing a servo device according to an eighth embodiment of the present invention.

FIG. 12 is a block diagram showing a servo device according to a ninth embodiment of the present invention.

FIG. 13 is a block diagram showing a conventional servo device.

[Description of Signs] 1 position command unit 2 position control unit 3 speed control unit 4 current control unit 5 power amplification unit 6 servo motor 7 encoder 8 differentiator 9 position command signal 10 position feedback signal 11 position deviation signal 12 speed command 13 speed Feedback signal 14 Speed deviation signal 15 Current command signal 16 Current feedback signal 17 Speed loop gain 18 Lower limit value of speed loop gain 19 Maximum value of speed loop gain 20 Variable setting value when speed loop gain is maximum 21 Speed loop gain 22 Absolute value conversion circuit 23 Differentiator 24 Sign decision unit 1 25 Sign decision unit 2 26 Smooth gain 27 Delay circuit 28 Absolute value circuit output signal 29 Differentiator output signal 30 Sign decision unit 1 output signal 31 Sign decision unit 2 output signal 32 Position deviation smoothing circuit 1 output signal 33 Position deviation flat Circuit 2 the output signal 34 the ideal position loop model 35 the ideal position loop model output signal 36 error signal 37 servo-system position error signal 38 positional deviation smoothing circuit 39 position deviation smoothing circuit between the ideal model and the actual position

Claims (5)

[Claims] A motor; a detecting means for detecting a position and a speed of the motor; a position calculating means for generating a speed command based on a difference between a position command input from outside and a position detection output of the detecting means. A speed calculating means for generating a torque command by multiplying a difference between the speed command and a speed detection output of the detecting means by a predetermined gain, and a current driving means for flowing a current to the motor based on the torque command, The servo device, wherein the gain is maximized at a position deviation, which is a difference between the position command and the position detection output of the detection means, at a predetermined magnitude. 2. An apparatus comprising an ideal position loop model, wherein a gain is maximized when a positional deviation, which is a difference between a current position signal output from the ideal position loop model and a position detection output of a detection means, is a predetermined magnitude. 2. The servo device according to claim 1, wherein: 3. A motor, a detecting means for detecting a position and a speed of the motor, and a speed command based on a position deviation which is a difference between a position command input from outside and a position detection output of the detecting means. Position calculating means, speed calculating means for generating a torque command by multiplying a speed difference, which is a difference between the speed command and the speed detection output of the detecting means, by a predetermined gain, and supplying a current to the motor based on the torque command And a current driving means, respectively, wherein the gain is obtained by calculating a position detection output of the detection means of the first servo apparatus and a position detection output of the detection means of the second servo apparatus. A servo device characterized in that a positional deviation, which is a difference, is maximized at a predetermined size. 4. A position deviation smoothing means for receiving a position deviation and outputting a signal in which a signal waveform indicating the position deviation has a gentle fall, wherein the gain is maximized when the signal has a predetermined magnitude. 2. The method according to claim 1, wherein
The servo device according to claim 3. 5. A signal to which a position deviation is input and which is a signal in which the falling edge of a signal waveform indicating the position deviation is gradual in a microscopic manner, and whose magnitude changes in a macroscopic manner in accordance with the fluctuation frequency of the position deviation. 4. The servo device according to claim 1, further comprising a position deviation smoothing means for outputting a signal, wherein the gain is maximized when the signal has a predetermined magnitude.