WO2023067682A1

WO2023067682A1 - Servomotor control device

Info

Publication number: WO2023067682A1
Application number: PCT/JP2021/038564
Authority: WO
Inventors: 高志岡本
Original assignee: ファナック株式会社
Priority date: 2021-10-19
Filing date: 2021-10-19
Publication date: 2023-04-27

Abstract

Provided is a servomotor control device that can correct the torque ripple of a servomotor with higher accuracy. The servomotor control device for controlling the servomotor is provided with: a learning control unit that, on the basis of a first command for learning control acquired from a host control device, performs learning control by an operation of the servomotor at a constant speed or an operation at a constant acceleration, and calculates correction data that correspond to the position of the servomotor or a driven body driven by the servomotor; and, a correction unit for acquiring a second command for driving the servomotor from the host control device, and applying the correction data to a command based on the second command.

Description

Servo motor controller

The present invention relates to a servo motor control device.

Conventionally, in order to control servo motors, learning control is known that minimizes control deviation by using the repeatability of motion. The learning control includes a time synchronization method that defines the time period of the repetitive operation and calculates the correction amount for each time sampling period of the learning control, There is known an angle synchronization method that calculates a correction amount at a reference position obtained by dividing the movement amount of . For example, Patent Literature 1 discloses a servo motor control device that performs angle-synchronous learning control on a driven body that periodically reciprocates.

JP 2011-269405 A

In such a servomotor, torque ripple, which is steady-state torque fluctuations such as changes in torque constant, cogging torque, and motor eccentricity, may occur. Therefore, there is a demand for a servomotor control device that can correct the torque ripple of the servomotor with higher accuracy.

A servo motor control device according to an aspect of the present disclosure is a servo motor control device that controls a servo motor, and controls the servo motor based on a first instruction for learning control acquired from a higher-level control device. a learning control unit that performs learning control by operating at a constant speed or operating at a constant acceleration, and calculates correction data according to the position of the servomotor or a driven body driven by the servomotor; a correction unit that acquires a second command for driving the motor from the host controller and applies the correction data to the command based on the second command.

According to the present invention, the torque ripple of the servomotor can be corrected with higher accuracy.

1 is a block diagram showing the configuration of a servo motor control device according to an embodiment; FIG. It is a figure which shows about control of the servomotor control apparatus which concerns on this embodiment. It shows the torque constant. It is a figure which shows about a correction coefficient. FIG. 11 is a block diagram showing a configuration of part of a servo motor control device in the case of correction pattern A; 8 is a diagram showing the relationship between the position of the servomotor, the commanded acceleration, and the torque command in the case of correction pattern A. FIG. 8 is a diagram showing the relationship between the position of the servomotor, phase data, and torque command in the case of correction pattern A; FIG. FIG. 4 is a diagram showing a correspondence relationship between phase data and torque commands; FIG. 5 is a diagram showing correction data calculated based on phase data and a torque command; FIG. 3 is a diagram showing a correspondence relationship between phase data and servo motor positions; It is a figure which shows the position of a servomotor, correction|amendment data, and correspondence. It is a figure which shows the correction|amendment data in a use range. It is a figure which shows the correction coefficient in a use range. 7 is a flowchart showing processing of the servo motor control device in the case of correction pattern A; It is a figure which shows disturbance torque. It is a figure which shows about the correction amount of a torque command. FIG. 11 is a block diagram showing a partial configuration of a servo motor control device in the case of correction pattern B; 8 is a diagram showing the relationship between the position of the servomotor or the position of the driven body, the commanded speed, and the torque command in the case of correction pattern B; FIG. 8 is a diagram showing the relationship between the position of the servomotor or the position of the driven body, phase data, and torque command in the case of correction pattern B; FIG. FIG. 4 is a diagram showing a correspondence relationship between phase data and torque commands; FIG. 4 is a diagram showing a correction amount calculated based on phase data and a torque command; It is a figure which shows the position of a servomotor or the position of a to-be-driven body, correction amount, and correspondence. FIG. 10 is a diagram showing the correction amount when the position of the servomotor or the driven body moves in the positive direction; FIG. 5 is a diagram showing a correction amount when the position of a servomotor or a driven body moves in the negative direction; 7 is a flowchart showing processing of the servo motor control device 1 in the case of correction pattern B; It shows the torque constant. It is a figure which shows about a correction coefficient. It is a figure which shows disturbance torque. It is a figure which shows about the correction amount of a torque command. FIG. 11 is a block diagram showing a partial configuration of a servo motor control device in the case of correction pattern C1; It is a figure which shows the learning data in a use range. It is a figure which shows the learning data in a use range. 10 is a flow chart showing processing of the servo motor control device in the case of correction pattern C1. It shows the torque constant. It is a figure which shows about a correction coefficient. It is a figure which shows about friction torque (constant disturbance torque). It is a figure which shows about the correction amount of a torque command. It is a figure which shows the learning data in a use range. FIG. 10 is a flowchart showing processing of the servo motor control device in the case of correction pattern C2; FIG.

<Structure of Servo Motor Controller>
An example of an embodiment of the present invention will be described below.
FIG. 1 is a block diagram showing the configuration of a servo motor control device 1 according to this embodiment. The servo control device 1 has a learning control section 17 that uses an angle synchronization method, and controls a servo motor 4 that periodically reciprocates a driven body.

As shown in FIG. 1, the servo motor control device 1 includes a command acquisition unit 10, a command generation unit 11, an adder 12, a position/speed control unit 13, an adder 14, a torque current control unit 15, A phase data generation unit 16 , a learning control unit 17 , a storage unit 18 , and a correction unit 19 are provided.

The command acquisition unit 10 acquires from the host controller 2 a first command for learning control and a second command for driving the servomotor. The command acquisition unit 10 outputs the acquired first command or second command to the command generation unit 11 . Here, the first command is, for example, a command 21 that repeats reciprocating motion, and the second command is, for example, a non-repetitive command 22 .

The command generation unit 11 generates torque, position and speed commands for driving the servomotor 4 based on the first command or the second command output from the command acquisition unit 10 . The command generator 11 outputs the generated commands to the adder 12 or the phase data generator 16 .

The adder 12 calculates the deviation between the command from the command generator 11 and the detected value from the detector 5 and outputs the deviation to the position/speed controller 13 .
The position/speed control unit 13 generates a torque command based on the deviation from the adder 12 and outputs it to the adder 14 .

The adder 14 adds the torque command from the position/speed control unit 13 and the correction data from the correction unit 19 and outputs the result to the torque current control unit 15 .

The torque current control unit 15 generates a current command based on the torque command and correction data, and outputs it to the amplifier 3. The servomotor 4 drives a driven body (motor driving section) based on the current command amplified by the amplifier 3 . The detector 5 detects the position and speed of the servomotor 4 or the position and speed of the driven body driven by the servomotor 4 and outputs (feedback) to the adder 12 .

Here, the servomotor 4 is, for example, a galvanomotor in a galvanoscanner, and is a three-phase motor or a single-phase motor. In this embodiment, the servo motor 4 is described assuming a galvano motor, but the present invention is not limited to this, and the servo motor 4 may be a motor used for other purposes.

The phase data generation unit 16 generates phase data for each servo control cycle based on the rotational speed or reciprocation cycle of the first command having repeatability and the servo control cycle of the servo motor control device 1 .

Here, assuming that the cycle of the first command having repeatability is T0 and the elapsed time is t, the phase θ is expressed as a function θ(t) of time t by the following formula.
θ(t)=360×(t/T0)

Assuming that the servo control period in the servo motor control device 1 is Ts, time Ts elapses for each servo control period. , t=Ts, and
θ(Ts)=360×(Ts/T0)
becomes.

Then, the phase θ when n cycles (n=1, 2, 3, . . . ) of the servo control cycle have passed is given by
θ(n)=360×(nTs/T0)
becomes.

Based on the phase data generated by the phase data generating unit 16 and the first command, the learning control unit 17 operates the servomotor 4 at a constant speed (for example, unidirectional rotation or reciprocating operation) or constant acceleration. Learning control is performed by the operation (for example, reciprocating operation) in , and correction data corresponding to the position of the servomotor 4 or the position of the driven body driven by the servomotor 4 is calculated. The learning control unit 17 performs learning control of the angle synchronization method. The learning control unit 17 also calculates, as correction data, a correction amount and/or a correction coefficient according to the position of the servomotor 4 or the position of the driven body driven by the servomotor 4 .

The storage unit 18 stores correction data calculated by the learning control unit 17 .
The correction unit 19 acquires a second command for driving the servomotor 4 from the host controller 2 and applies the correction data stored in the storage unit 18 based on the second command. Specifically, the correction unit 19 applies the correction data stored in the storage unit 18 to the torque command from the position/speed control unit 13 .

FIG. 2 is a diagram showing the control of the servomotor control device 1 according to this embodiment. The servo motor control device 1 according to the present embodiment uses a correction pattern A, a correction pattern B, and correction patterns C1 and C2 as shown in FIG. 2 in order to correct the torque ripple.

<Correction pattern A>
As shown in FIG. 2, in the correction pattern A, the correction target is correction of changes in the torque constant, and the instruction (first instruction) during learning control is to reciprocate the driven body or the servomotor 4 at a constant acceleration. Contains commands to perform actions. The correction data calculated by learning control is a correction coefficient for correcting the torque constant. The target servomotor 4 is an ideal single-phase motor that does not consider friction torque.

FIG. 3A shows the torque constant _kT , and FIG. 3B shows the correction coefficient δ. As shown in FIG. 3A, when the servomotor 4 is a single-phase motor, the torque constant _kT varies according to the position of the servomotor 4 . Therefore, as shown in FIG. 3B, it is desirable that the correction coefficient _.delta .

FIG. 4 is a block diagram showing a partial configuration of the servo motor control device 1 in the case of the correction pattern A. As shown in FIG. As shown in FIG. 4, the correction unit 19 corrects changes in the torque constant _kT by applying a correction coefficient δ to the torque command output from the position/speed control unit 13 . Then, the corrected torque command is output to the torque current control section 15 .

FIG. 5 is a diagram showing the relationship between the position of the servomotor 4, the commanded acceleration, and the torque command in the case of the correction pattern A. FIG. 6 is a diagram showing the relationship between the position of the servomotor 4, the phase data, and the torque command in the case of the correction pattern A. In FIG. The phase data in FIG. 6 are generated by the phase data generator 16 as described above.

　As shown in Figures 5 and 6, a torque ripple due to a change in the torque constant occurs in the torque command corresponding to a constant portion of the commanded acceleration. 5 and 6 indicate the range in which the driven body actually operates.

FIG. 7 is a diagram showing the correspondence relationship between phase data and torque commands. FIG. 8 is a diagram showing learning data calculated based on the phase data and the torque command.
As shown in FIG. 7, the learning control unit 17 performs learning control based on the phase data and the torque command in each servo control cycle (one cycle), and calculates learning data as shown in FIG.

FIG. 9 is a diagram showing the correspondence relationship between the phase data and the position of the servomotor 4. FIG. FIG. 10 is a diagram showing the correspondence between the position of the servo motor 4 and the learning data.

The learning control unit 17 calculates the correspondence relationship between the position of the servomotor 4 and the learning data shown in FIG. 10 from the correspondence relationships in FIGS. Thereby, the learning control section 17 can calculate the learning data in the use range of the servo motor 4 .

FIG. 11A is a diagram showing learning data in the use range of the driven body or the servomotor 4, and FIG. 11B is a diagram showing correction coefficients in the use range.

The learning control unit 17 can calculate the correction coefficients shown in FIG. 11B by normalizing the learning data T ₁ (θ) shown in FIG. 11A based on the minimum value Tb. In FIG. 11A, if the torque constant k _T is constant, the learning data T ₁ (θ) becomes Tmin, which is a constant value.

Further, the learning data T ₁ (θ) obtained when the servomotor 4 is operated at a constant acceleration corresponding to the torque command Tmin has a correction amount (=0) and a correction coefficient δ as shown in the following equation. can be considered included.
T ₁ (θ)=(Tmin+0)δ(θ)

The learning control unit 17 may calculate both the correction coefficient when the servomotor 4 moves in the positive direction and the correction coefficient when the servomotor 4 moves in the negative direction. You may

FIG. 12 is a flow chart showing the processing of the servo motor control device 1 in the case of the correction pattern A. As shown in FIG.
In step S1 , the command acquisition unit 10 acquires a first command for learning control from the host controller 2 . Here, the first command is a repetitive command.

In step S2, the command generation unit 11 generates torque, position, and speed commands for driving the servomotor 4 based on the first command output from the command acquisition unit 10. The command generator 11 outputs the generated commands to the phase data generator 16 .

In step S3, the phase data generator 16 generates phase data for each servo control cycle based on the reciprocating cycle of the first command having repeatability and the servo control cycle of the servo motor control device 1.

In step S4, the learning control unit 17 performs learning control by reciprocating the servo motor 4 at a constant acceleration based on the command generated from the generated phase data and the first command. A correction coefficient corresponding to the position is calculated. The learning control unit 17 stores the calculated correction coefficient in the storage unit 18 .

In step S5, the command acquisition unit 10 acquires a second command for actually driving the servomotor 4 from the host controller 2. Here, the second command may or may not have repeatability.

In step S6, the command generation unit 11 generates torque, position, and speed commands for driving the servomotor 4 based on the second command output from the command acquisition unit 10. Command generator 11 outputs the generated command to adder 12 . After that, the adder 12 calculates the deviation between the command from the command generator 11 and the detection value from the detector 5 and outputs it to the position/speed controller 13 . The position/speed control unit 13 generates a torque command based on the deviation from the adder 12 and outputs it to the adder 14 .

In step S7, the correction unit 19 refers to the actual position of the servomotor 4 output from the detector 5, and applies the correction coefficient stored in the storage unit 18 to the torque command generated from the second command. Thereby, the servo motor control device 1 corrects changes in the torque constant of the servo motor 4 .

<Correction pattern B>
As shown in FIG. 2, in the correction pattern B, the correction target is the correction of the phase-dependent disturbance torque, and the instruction (first instruction) during the learning control is the unidirectional rotation of the driven body at a constant speed. Contains commands to move or reciprocate. The correction data calculated by learning control is a correction amount for correcting the disturbance torque. The target servomotor 4 is the main shaft of an actual three-phase motor (corresponding to unidirectional rotary motion at constant speed) or feed shaft (corresponding to reciprocating motion at constant speed).

FIG. 13A is a diagram showing the disturbance torque _TL , and FIG. 13B is a diagram showing the torque command correction amount _TC . As shown in FIG. 13A, when the servomotor 4 is a three-phase synchronous motor, the disturbance torque _TL includes cogging torque and friction torque, and varies according to the position of the servomotor 4 or the position of the driven body. Therefore, as shown in FIG. 13B, the correction amount _TC is preferably a value corresponding to the position of the servomotor 4 or the position of the driven body in order to correct the change in the disturbance torque _TL .

FIG. 14 is a block diagram showing a partial configuration of the servo motor control device 1 in the case of the correction pattern B. As shown in FIG. As shown in FIG. 14, the correction unit 19 corrects changes in the disturbance torque _TL by applying the correction amount _TC to the torque command output from the position/speed control unit 13 . Then, the corrected torque command is output to the torque current control section 15 . 1/Js ² in FIG. 14 indicates the transfer function of the servomotor 4 .

FIG. 15 is a diagram showing the relationship between the position of the servomotor 4 or the position of the driven body, command speed, and torque command in the case of correction pattern B. FIG. As shown in FIG. 15, a torque command corresponding to a constant speed portion in which no acceleration or deceleration is performed generates disturbance torque depending on the position of the servomotor 4 or the position of the driven body. Therefore, a torque ripple is generated in the torque command due to the generated disturbance torque. In the correction pattern B, the learning control unit 17 executes learning control using the reciprocating motion of the driven body at a constant speed as shown in FIGS. In pattern B, learning control may be performed using a unidirectional rotational motion of the driven body at a constant speed.

FIG. 16 is a diagram showing the relationship between the position of the servomotor 4 or the position of the driven body, the phase data and the torque command in the case of the correction pattern B. FIG. The phase data in FIG. 16 are generated by the phase data generator 16 as described above.

As shown in FIG. 16, the output value of the torque command differs when the servomotor 4 or the driven body moves in the positive direction and when it moves in the negative direction. Phase data is generated with a reciprocating motion as one cycle. 15 and 16, the use range of the position of the servomotor 4 or the position of the driven body indicates the range in which the position of the servomotor 4 or the driven body actually operates.

FIG. 17 is a diagram showing the correspondence relationship between phase data and torque commands. FIG. 18 is a diagram showing correction amounts calculated based on phase data and torque commands. As shown in FIG. 17, the learning control unit 17 performs learning control based on the phase data and the torque command in each servo control cycle (one cycle), and calculates the correction amount as shown in FIG.

FIG. 19 is a diagram showing the relationship between the position of the servomotor 4 or the position of the driven body and the correction amount. The learning control unit 17 calculates the position of the servomotor 4 or the position of the driven body and the correction amount shown in FIG. 19 from the correspondence relationship between the phase data and the correction amount shown in FIG. Thereby, the learning control section 17 can calculate the correction amount in the use range of the servo motor 4 or the driven body. As shown in FIG. 19, since the servomotor 4 or the driven body is reciprocating, the value of the correction amount has a shape that is folded around the 180-degree point.

FIG. 20 shows the amount of correction when the servomotor 4 or the driven body moves in the positive direction, and FIG. 21 shows the amount of correction when the servomotor 4 or the driven body moves in the negative direction. It is a diagram. The learning control unit 17 extracts the correction amounts shown in FIGS. 20 and 21 with the following three patterns.

In pattern 1, the learning control unit 17 extracts only the correction amount of the use range when the servomotor 4 or the driven body moves in the positive direction. In this case, when the servomotor 4 or the driven body moves in the positive direction, the learning control unit 17 inverts the polarity of the correction amount and applies it to the actual operation command.

In pattern 2, the learning control unit 17 calculates the average value of the correction amount of the use range when the servo motor 4 or the driven body moves in the positive direction and the correction amount x (-1) when the servo motor 4 or the driven body moves in the negative direction. is extracted as a correction amount when the servomotor 4 or the driven body moves in the positive direction.

In pattern 3, the learning control unit 17 extracts both the correction amount of the use range when the servo motor 4 or the driven body moves in the positive direction and the correction amount of the use range when it moves in the negative direction. . In this case, the learning control unit 17 applies two correction amounts to the actual operation command.

FIG. 22 is a flow chart showing the processing of the servo motor control device 1 in the case of the correction pattern B. FIG.
In step S11 , the command acquisition unit 10 acquires a first command for learning control from the host controller 2 . Here, the first command is a repetitive command.

In step S12, the command generation unit 11 generates torque, position, and speed commands for driving the servomotor 4 based on the first command output from the command acquisition unit 10. The command generator 11 outputs the generated commands to the phase data generator 16 .

In step S13 , the phase data generation unit 16 calculates the phase data for each servo control cycle based on the reciprocating cycle of the first command having repeatability or the rotation speed of the rotary operation and the servo control cycle of the servo motor control device 1 . Generate data.

In step S14, the learning control unit 17 performs learning control by rotating or reciprocating the servomotor 4 at a constant speed based on the command generated from the generated phase data and the first command. A correction amount corresponding to the position of the motor 4 or the position of the driven body driven by the servomotor 4 is calculated. The learning control unit 17 stores the calculated correction amount in the storage unit 18 .

In step S15, the command acquisition unit 10 acquires a second command for actually driving the servomotor 4 from the host controller 2. Here, the second command may or may not have repeatability.

In step S16, the command generation unit 11 generates torque, position, and speed commands for driving the servomotor 4 based on the second command output from the command acquisition unit 10. Command generator 11 outputs the generated command to adder 12 . After that, the adder 12 calculates the deviation between the command from the command generator 11 and the detection value from the detector 5 and outputs it to the position/speed controller 13 . The position/speed control unit 13 generates a torque command based on the deviation from the adder 12 and outputs it to the adder 14 .

In step S17, the correction unit 19 refers to the position of the servomotor 4 output from the detector 5 or the actual position of the driven body, and the correction amount stored in the storage unit 18 is generated from the second command. Applies to torque commands. Thereby, the servo motor control device 1 corrects changes in disturbance torque of the servo motor 4 or the driven body driven by the servo motor 4 .

<Correction pattern C1>
As shown in FIG. 2, in the correction pattern C1, correction targets are changes in torque constant and correction of phase-dependent disturbance torque. A command (first command) during learning control includes a command for reciprocating the driven body (two patterns) at a constant acceleration. The correction data calculated by the learning control are a correction coefficient for correcting the torque constant and a correction amount for correcting the disturbance torque. The subject servomotor 4 is a more strictly real single-phase motor.

FIG. 23A shows the torque constant _kT , and FIG. 23B shows the correction coefficient δ. As shown in FIG. 23A, when the servomotor 4 is a single-phase motor, the torque constant k _T changes according to the position of the servomotor 4 . Therefore, as shown in FIG. 23B, it is desirable that the correction coefficient _.delta .

FIG. 23C is a diagram showing the disturbance torque _TL , and FIG. 23D is a diagram showing the torque command correction amount _TC . As shown in FIG. 23C, when the servomotor 4 is a single-phase motor, the disturbance torque _TL includes cogging torque and friction torque, and varies according to the position of the servomotor 4 or the position of the driven body. Therefore, as shown in FIG. 23D, the correction amount _TC is preferably a value corresponding to the position of the servomotor 4 or the position of the driven body in order to correct the change in the disturbance torque _TL .

FIG. 24 is a block diagram showing a partial configuration of the servo motor control device 1 in the case of the correction pattern C1. As shown in FIG. 24, the correction unit 19 applies the correction amount _TC and the correction coefficient δ to the torque command output from the position/speed control unit 13 to change the disturbance torque _TL and the torque constant _kT . Compensate for changes. Then, the corrected torque command is output to the torque current control section 15 .

Thus, the correction pattern C1 is a pattern obtained by combining the correction pattern A and the correction pattern B. FIG. The learning control unit 17 calculates the correction amount _TC and the correction coefficient δ by performing the same processes as those for the correction pattern B and the correction pattern A described above, as well as the processes described below.

FIG. 25A is a diagram showing learning data T ₁ (θ) in the usage range. The learning data T ₁ (θ) is calculated by performing a reciprocating motion at a constant acceleration corresponding to the torque command T _1a and performing learning control.

FIG. 25B is a diagram showing learning data T ₂ (θ) in the usage range. The learning data T ₂ (θ) is calculated by performing learning control by reciprocating at a constant acceleration corresponding to the torque command T _2a different from the torque command T _1a .

The learning data T ₁ (θ) includes the correction amount T _C (θ) and the correction coefficient δ(θ) as follows.
T ₁ (θ)=(T _1a + _TC (θ)) δ(θ) (1)
Here _, it is necessary to separate the correction amount T _C (θ) and the correction coefficient δ(θ). and cannot be separated. Therefore, the servo control device 1 performs reciprocating motion with constant acceleration in two patterns of T ₁ (θ) and T ₂ (θ).

The learning data T ₂ (θ) includes the correction amount T _C (θ) and the correction coefficient δ(θ) as follows.
T ₂ (θ)=(T _2a + _TC (θ)) δ(θ) (2)

The correction amount T _C (θ) and the correction factor δ(θ) can be separated from equations (1) and (2) and are shown below.
δ(θ)=(T ₂ (θ)−T ₁ (θ))/(T _2a −T _1a )
T _C (θ)=(T _2a T ₁ (θ)−T _1a T ₂ (θ))/(T ₂ (θ)−T ₁ (θ))

FIG. 26 is a flow chart showing the processing of the servo motor control device 1 in the case of the correction pattern C1.
In step S21 , the command acquisition unit 10 acquires a first command for learning control from the host controller 2 . Here, the first command is a repetitive command. Also, the first command includes torque command T _1a or torque command T _2a in order to obtain learning data T ₁ (θ) and T ₂ (θ) described above.

In step S22, the command generation unit 11 generates torque, position, and speed commands for driving the servomotor 4 based on the first command output from the command acquisition unit 10. The command generator 11 outputs the generated commands to the phase data generator 16 .

In step S23, the phase data generator 16 generates phase data for each servo control cycle based on the reciprocating cycle of the first command having repeatability and the servo control cycle of the servo motor control device 1.

In step S24, the learning control unit 17 performs learning control by reciprocating the driven body at a constant speed by the servo motor 4 based on the command generated from the generated phase data and the first command, Learning data corresponding to the position of the servomotor 4 or the position of the driven body driven by the servomotor 4 is calculated. The learning control unit 17 stores the calculated learning data in the storage unit 18 .

In step S25, the learning control unit 17 determines whether or not learning control has been executed twice. If the learning control has been performed twice (YES), the process proceeds to step S26. On the other hand, if learning control has not been executed twice (NO), the process proceeds to step S21.

In step S26, the learning control unit 17 uses the above-described formulas ( ₁ ) and ( ₂ ) to obtain the correction amount Calculate T _C (θ) and correction coefficient δ(θ). The learning control unit 17 stores the calculated correction amount T _C (θ) and correction coefficient δ(θ) in the storage unit 18 .

In step S27, the command acquisition unit 10 acquires a second command for actually driving the servomotor 4 from the host controller 2. Here, the second command may or may not have repeatability.

In step S28, the command generation unit 11 generates torque, position, and speed commands for driving the servomotor 4 based on the second command output from the command acquisition unit 10. Command generator 11 outputs the generated command to adder 12 . After that, the adder 12 calculates the deviation between the command from the command generator 11 and the detection value from the detector 5 and outputs it to the position/speed controller 13 . The position/speed control unit 13 generates a torque command based on the deviation from the adder 12 and outputs it to the adder 14 .

In step S29, the correction unit 19 refers to the actual position of the servo motor 4 or the driven body output from the detector 5, and the correction amount T _C (θ) and the correction coefficient δ(θ ) to the torque command of the command generated from the second command. Thereby, the servo motor control device 1 corrects changes in the torque constant and changes in the disturbance torque.

<Correction pattern C2>
As shown in FIG. 2, in the correction pattern C2, correction targets are changes in the torque constant and correction of the friction torque. A command (first command) during learning control includes a command for reciprocating the driven body at a constant speed. The correction data calculated by the learning control are a correction coefficient for correcting the torque constant and a correction amount for correcting the friction torque (constant disturbance torque). The target servomotor 4 is an actual single-phase motor.

FIG. 27A shows the torque constant _kT , and FIG. 27B shows the correction coefficient δ. As shown in FIG. 27A, when the servomotor 4 is a single-phase motor, the torque constant _kT changes according to the position of the servomotor 4. As shown in FIG. Therefore, as shown in FIG. 27B, it is desirable that the correction coefficient _.delta .

FIG. 27C is a diagram showing the friction torque (constant disturbance torque) _TL , and FIG. 27D is a diagram showing the torque command correction amount _TC . As shown in FIG. 27C, the friction torque (constant disturbance torque) _TL is constant regardless of the position of the servomotor 4 or the driven body. Therefore, as shown in FIG. 27D, it is desirable that the correction amount T _C be a constant value in order to correct the friction torque (constant disturbance torque) T _L .

Thus, the correction pattern C2 is a combination of the correction pattern A and the correction pattern B, like the correction pattern C1. The learning control unit 17 calculates the correction amount _TC and the correction coefficient δ by performing the same processes as those for the correction pattern B and the correction pattern A described above, as well as the processes described below.

FIG. 28 is a diagram showing learning data T ₁ (θ) in the usage range.
As shown in FIG. 28, the learning data T ₁ (θ) is calculated by reciprocating the driven body at a constant speed and performing learning control. The learning data T ₁ (θ) can be considered to include the correction amount T _C and the correction coefficient δ(θ), as in Equation (3) below.
T ₁ (θ)=(0+ _TC ) δ(θ) (3)

The learning control unit 17 can calculate the correction amount T _C and the correction coefficient δ(θ) as follows by using Equation (3).
_TC = Tmin
δ(θ)=T ₁ (θ)/Tmin

FIG. 29 is a flow chart showing the processing of the servo motor control device 1 in the case of the correction pattern C2.
In step S31 , the command acquisition unit 10 acquires a first command for learning control from the host controller 2 . Here, the first command is a repetitive command.

In step S32, the command generation unit 11 generates torque, position and speed commands for driving the servomotor 4 based on the first command output from the command acquisition unit 10. The command generator 11 outputs the generated commands to the phase data generator 16 .

In step S33, the phase data generator 16 generates phase data for each servo control cycle based on the reciprocating cycle of the first command having repeatability and the servo control cycle of the servo motor control device 1.

In step S34, the learning control unit 17 performs learning control by reciprocating the driving body driven by the servomotor 4 at a constant speed based on the command generated from the generated phase data and the first command. Then, a correction amount corresponding to the position of the servomotor 4 or the driven body driven by the servomotor 4 is calculated. The learning control unit 17 stores the calculated correction amount in the storage unit 18 .

In step S35, the command acquisition unit 10 acquires a second command for actually driving the servomotor 4 from the host controller 2. Here, the second command may or may not have repeatability.

In step S36, the command generation unit 11 generates torque, position, and speed commands for driving the servomotor 4 based on the second command output from the command acquisition unit 10. Command generator 11 outputs the generated command to adder 12 . After that, the adder 12 calculates the deviation between the command from the command generator 11 and the detection value from the detector 5 and outputs it to the position/speed controller 13 . The position/speed control unit 13 generates a torque command based on the deviation from the adder 12 and outputs it to the adder 14 .

In step S37, the correction unit 19 refers to the actual position of the driven body output from the detector 5, and converts the correction amount _TC and the correction coefficient δ(θ) stored in the storage unit 18 from the second command. Applies to the torque command of the generated command. Thereby, the servo motor control device 1 corrects the change in the torque constant and the constant disturbance torque.

As described above, according to the present embodiment, the servo motor control device 1 operates the servo motor 4 at a constant speed based on the first instruction for learning control acquired from the host control device 2. Alternatively, a learning control unit 17 that performs learning control by operating at a constant acceleration and calculates correction data according to the position of the servomotor 4 or the position of the driven body driven by the servomotor 4, and drives the servomotor 4. and a correction unit 19 that acquires a second command for performing from the host controller 2 and applies correction data to the command based on the second command.

As a result, the servo motor control device 1 calculates correction data using learning control, and applies the calculated correction data to the second command, thereby correcting the second command. Therefore, the servomotor control device 1 can correct the torque ripple according to the position of the servomotor 4 or the position of the driven body driven by the servomotor 4 with higher accuracy.

Further, the servo motor control device 1 generates phase data for each servo control cycle based on the rotational speed or the reciprocating cycle of the first command having repeatability and the servo control cycle of the servo motor control device 1. A data generation unit 16 is further provided, and the learning control unit 17 performs learning control by operating the servomotor 4 at a constant speed or at a constant acceleration based on the generated phase data and the first command. , the correction data corresponding to the position of the servomotor 4 or the position of the driven body driven by the servomotor 4 is calculated.

As a result, the servo motor control device 1 calculates correction data using the generated phase data. Therefore, the servo motor control device 1 can correct the torque ripple according to the position of the driven body with higher accuracy using the correction data using the phase data.

The learning control unit 17 also calculates, as correction data, a correction amount and/or a correction coefficient according to the position of the servomotor 4 or the driven body. As a result, the servo motor control device 1 can use the correction amount and/or the correction coefficient to accurately correct changes in disturbance torque, friction torque, and torque constant according to the position of the driven body.

In addition, the servomotor control device 1 further includes a command acquisition unit 10 that acquires the first command and the second command from the host control device 2 . As a result, the servo motor control device 1 can correct the torque ripple according to the position of the driven body with higher accuracy using the command acquired from the host control device 2 .

The servomotor control device 1 further includes a command generator 11 that generates a command for driving the servomotor 4 based on the first command and the second command acquired by the command acquirer 10 . As a result, the servomotor control device 1 can use the command for driving the servomotor 4 to correct the torque ripple according to the position of the servomotor 4 or the position of the driven body with higher accuracy.

Further, the learning control unit 17 performs learning control by reciprocating motion of the servomotor 4 at a constant acceleration based on the phase data and the first command, calculates a correction coefficient according to the position of the servomotor 4, The correction unit 19 corrects changes in the torque constant of the servomotor 4 by applying the correction coefficient to the torque command based on the second command. As a result, the servomotor control device 1 can correct changes in the torque constant of the servomotor 4 with high accuracy.

Further, the learning control unit 17 performs learning control by rotating or reciprocating the servomotor 4 at a constant speed based on the phase data and the first command, and determines the position of the servomotor 4 or the driving by the servomotor 4. The correction unit 19 applies the correction amount to the torque command based on the second command, so that the servo motor 4 or the object driven by the servo motor 4 is calculated. Correct the disturbance torque of the driving body. As a result, the servo motor control device 1 can accurately correct changes in disturbance torque including cogging torque and friction torque.

Further, the learning control unit 17 performs learning control by reciprocating motion of the servomotor 4 at a constant acceleration based on the phase data and the first command, and determines the position of the servomotor 4 or the object driven by the servomotor 4 . A correction amount and a correction coefficient corresponding to the position of the driving body are calculated, and the correction unit 19 applies the correction amount to the torque command based on the second command, thereby changing the torque constant of the servomotor 4 and Alternatively, changes in disturbance torque of the driven body driven by the servomotor 4 are corrected. As a result, the servo motor control device 1 can correct changes in the torque constant and changes in the disturbance torque with high accuracy.

The learning control unit 17 performs learning control by reciprocating the servomotor 4 at a constant speed based on the phase data and the first command, and determines the position of the servomotor 4 or the object driven by the servomotor 4 . A correction amount and a correction coefficient corresponding to the position of the driving body are calculated, and the correction unit 19 applies the correction amount to the torque command based on the second command, thereby changing the torque constant of the servomotor 4 and Alternatively, the constant disturbance torque of the driven body driven by the servomotor 4 is corrected. As a result, the servo motor control device 1 can correct changes in the torque constant and changes in the constant disturbance torque with high accuracy.

Although the embodiments of the present invention have been described above, the servo motor control device 1 can be realized by hardware, software, or a combination thereof. Also, the control method performed by the robot 1 described above can be realized by hardware, software, or a combination thereof. Here, "implemented by software" means implemented by a computer reading and executing a program.

Programs can be stored and supplied to computers using various types of non-transitory computer readable media. Non-transitory computer-readable media include various types of tangible storage media. Examples of non-transitory computer-readable media include magnetic recording media (e.g., hard disk drives), magneto-optical recording media (e.g., magneto-optical discs), CD-ROMs (Read Only Memory), CD-Rs, CD-R/ W, semiconductor memory (eg, mask ROM, PROM (Programmable ROM), EPROM (Erasable PROM), flash ROM, RAM (random access memory)).

In addition, although each of the above-described embodiments is a preferred embodiment of the present invention, the scope of the present invention is not limited to only the above-described embodiments, and various modifications can be made without departing from the scope of the present invention. It is possible to implement it in the form applied.

1 servo motor controller 2 host controller 3 amplifier 4 servo motor 5 detector 10 command acquisition unit 11 command generation unit 12 adder 13 position/speed control unit 14 adder 15 torque current control unit 16 phase data generation unit 17 learning control unit 18 storage unit 19 correction unit

Claims

A servo motor control device for controlling a servo motor,
Based on a first command for learning control acquired from a host controller, learning control is performed by operating the servomotor at a constant speed or operating at a constant acceleration, and the servomotor or the servomotor a learning control unit that calculates correction data according to the position of the driven body to be driven;
a correction unit that acquires a second command for driving the servomotor from the host controller and applies the correction data to a command based on the second command;
A servo motor controller comprising:
Further comprising a phase data generation unit that generates phase data for each servo control cycle based on the rotational speed or reciprocation cycle of the first command having repeatability and the servo control cycle of the servo motor control device,
The learning control unit performs learning control by operating the servomotor at a constant speed or operating at a constant acceleration based on the generated phase data and the first command. 2. The servomotor control device according to claim 1, which calculates correction data according to the position of a driven body driven by the servomotor.
The servo motor control device according to claim 1 or 2, wherein the learning control unit calculates, as the correction data, a correction amount and/or a correction coefficient according to the position of the servo motor or the driven body.
4. The servo motor control device according to any one of claims 1 to 3, further comprising a command acquisition unit that acquires the first command and the second command from the host control device.
5. The servomotor according to claim 4, further comprising a command generation unit that generates a command for driving the servomotor based on the first command and the second command acquired by the command acquisition unit. Control device.
The learning control unit performs learning control by reciprocating motion of the servomotor at a constant acceleration based on the phase data and the first command, calculates a correction coefficient according to the position of the servomotor,
The correction unit corrects changes in the torque constant of the servomotor by applying the correction coefficient to the torque command based on the second command.
3. A servo motor control device according to claim 2.
The learning control unit performs learning control based on the phase data and the first command by rotating or reciprocating the servomotor at a constant speed, and is driven by the servomotor or the servomotor. Calculate the correction amount according to the position of the driven body,
The correction unit corrects disturbance torque of the servomotor or a driven body driven by the servomotor by applying the correction amount to the torque command based on the second command.
3. A servo motor control device according to claim 2.
The learning control unit performs learning control by reciprocating motion of the servomotor at a constant acceleration based on the phase data and the first command, and the servomotor or a driven body driven by the servomotor. Calculate the correction amount and correction coefficient according to the position of
By applying the correction amount to the torque command based on the second command, the correction unit corrects changes in the torque constant of the servomotor and disturbance torque of the servomotor or a driven body driven by the servomotor. to compensate for changes in
3. A servo motor control device according to claim 2.
The learning control unit performs learning control by reciprocating the servomotor at a constant speed based on the phase data and the first command, and the servomotor or a driven body driven by the servomotor. Calculate the correction amount and correction coefficient according to the position of
The correction unit applies the correction amount to the torque command based on the second command, thereby reducing the change in the torque constant of the servomotor and the constant disturbance of the servomotor or the driven body driven by the servomotor. to compensate for torque,
3. A servo motor control device according to claim 2.