SERVOMOTOR CONTROL DEVICE, SERVOMOTOR CONTROL METHOD, AND COMPUTER READABLE RECORDING MEDIUM

• US 20180200882A1
• Filed: 01/04/2018
• Published: 07/19/2018
• Est. Priority Date: 01/13/2017
• Status: Abandoned Application

• Current Assignee: Fanuc Corporation
• Original Assignee: Fanuc Corporation
• Inventors: SHINODA, Shougo, IKAI, Satoshi
• Application Number:
  US15/862,166
• Publication Number:
  US 20180200882A1
• Time in Patent Office: Days
• CPC Class Codes: B25J 3/04 involving servo mechanisms servo-actuated heads B25J15/02
• CPC Class Codes: B25J 9/1085 positioning by means of shape-memory materials shape memory actuators F03G7/06
• CPC Class Codes: B25J 9/1633 compliant, force, torque control, e.g. combined with position control
• CPC Class Codes: G05B 19/404 characterised by control arrangements for compensation, e.g. for backlash, overshoot, tool offset, tool wear, temperature, machine construction errors, load, inertia G05B19/19, G05B19/41 take precedence
• CPC Class Codes: G05B 2219/41138 Torque compensation

Abstract

A servomotor control device includes: a driven body configured to be driven by a servomotor; a connection mechanism configured to connect the servomotor and the driven body; a position command generation unit configured to generate a position command value for the driven body; a motor control unit configured to control the servomotor using the position command value; a force estimation part configured to estimate a force estimated value which is a drive force acting on the driven body at a connecting part with the connection mechanism; and a compensation amount generation part configured to generate a compensation amount for compensation the position command value generated by the position command generation part, using a product of the force estimated value and a coefficient indicating a physical constant, in which the coefficient indicating the physical constant changes by the force estimated value or a magnitude of the compensation amount thus generated.

Claims

1. A servomotor control device, comprising:

a servomotor;

a driven body configured to be driven by the servomotor;

a connection mechanism configured to connect the servomotor and the driven body to transfer power of the servomotor to the driven body;

a position command generation unit configured to generate a position command value for the driven body;

a motor control unit configured to control the servomotor using the position command value;

a force estimation unit configured to estimate a force estimated value which is drive force acting on the driven body at a connecting part with the connection mechanism;

a compensation amount generation part configured to generate a compensation amount for compensating the position command value generated by the position command generation unit, using a product of the force estimated value and a coefficient indicating a physical constant; and

a coefficient setting unit configured to change the coefficient indicating the physical constant by the force estimated value or a magnitude of the compensation amount generated.

2. The servomotor control device according to claim 1,

wherein the compensation amount generation part sets, as the compensation amount, the sum of a product of the force estimated value and a first coefficient, and a product of the force estimated value, distance from the servomotor until the connecting part, and a second coefficient, and

wherein the product of the force estimated value and the first coefficient is a product of the force estimated value and a coefficient indicating a physical constant.

3. The servomotor control device according to claim 1, wherein the coefficient indicating the physical constant is continuously or discretely made smaller based on the force estimated value estimated by the force estimation unit, upon an absolute value for the force estimated value becoming large than a predetermined value.

4. The servomotor control device according to claim 1, wherein the coefficient indicating the physical constant is continuously or discretely made smaller based on the compensation amount generated by the compensation amount generation part, upon an absolute value for the compensation amount that was generated becoming greater than a predetermined value.

5. A servomotor control method for a servomotor control device including:

a servomotor;

a driven body configured to be driven by the servomotor; and

a connection mechanism configured to connect the servomotor and the driven body to transfer power of the servomotor to the driven body,

the method comprising the steps of;

generating a position command value for the driven body;

estimating a force estimated value which is a drive force acting on the driven body at a connecting part with the connection mechanism;

compensating the position command value by a compensation amount generated using a product of the force estimated value thus estimated and a coefficient indicating a physical constant; and

controlling the servomotor using the position command value thus compensated,

wherein the coefficient indicating the physical constant changes by the force estimated value or a magnitude of the compensation amount thus generated.

6. The servomotor control method according to claim 5, wherein the compensation value for compensating the position command value is the sum of a product of the force estimated value and a first coefficient, and a product of the force estimated value, distance from the servomotor until the connecting part, and a second coefficient, and

wherein the product of the force estimated value and first coefficient is a product of the force estimated value and a coefficient indicating a physical constant.

7. The servomotor control method according to claim 5, wherein the coefficient indicating the physical constant is continuously or discretely made smaller based on the estimated value thus estimated, upon an absolute value for the force estimated value becoming greater than a predetermined value.

8. The servomotor control method according to claim 5, wherein the coefficient indicating the physical constant is continuously or discretely made smaller based on the compensation amount thus generated, upon an absolute value for the compensation amount thus generated becoming greater than a predetermined value.

9. A non-transitory computer readable recording medium encoded with a program for servomotor control that causes a computer to execute servomotor control of a servomotor control device including:

a servomotor;

a driven body configured to be driven by the servomotor; and

a connection mechanism configured to connect the servomotor and the driven body to transfer power of the servomotor to the driven body, the program causing the computer to execute processing of;

generating a position command value for the driven body;

estimating a force estimated value that is a drive force acting on the driven body at a connecting part with the connection mechanism;

compensating the position command value with a compensation amount generated using a product of the force estimated value thus estimated and a coefficient indicating a physical constant; and

controlling the servomotor using the position command value thus compensated,

wherein the coefficient indicating the physical constant changes by the force estimated value or magnitude of the compensation amount thus generated.