Servocontrol system and method of setting

• US 20040135532A1
• Filed: 10/30/2003
• Published: 07/15/2004
• Est. Priority Date: 07/04/2001
• Status: Active Grant

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Tomatsuri, Kazuhiko, Matsumoto, Hidehiko, Imahashi, Aya
• Granted Patent: US 6,949,905 B2
• Time in Patent Office: Days
• US Class Current: 318/568.22
• 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 2219/43174 Simulating cam motion mechanism

Abstract

A servo control system which comprises an original cam pattern generator 11 for generating a first pattern of a cam shape relative to a phase corresponding to one revolution of a cam mechanism; a corrector 14 for differentiating the original pattern of the original pattern generator 11 with respect to time, multiplying the differentiation value by a constant to find a multiplication value, and subtracting a predetermined phase from the multiplication value to generate a correction cam pattern; and a position command device 14 for adding the above-mentioned correction pattern to the above-mentioned original pattern to generate a second pattern and generating a position command of the above-mentioned servomotor based on the phase corresponding to one revolution of the above-mentioned cam mechanism using the second pattern.

Claims

1. A servo control system for causing a servo motor to perform operation equivalent to a cam mechanism, the servo control system comprising:

pattern generation means for generating a first pattern of a cam shape relative to a phase corresponding to one revolution of the above-mentioned cam mechanism;

correction means for differentiating the first pattern of the pattern generation means with respect to time, multiplying the differentiation value by a constant to find a multiplication value, and subtracting a predetermined phase from the multiplication value, thereby generating a correction pattern; and

position command generation means for adding the above-mentioned correction pattern to the above-mentioned first pattern to generate a second pattern and generating a position command of the above-mentioned servomotor based on the phase corresponding to one revolution of the above-mentioned cam mechanism using the second pattern.

2. A setting method of a servo control system as claimed in claim 1, the setting method of

executing a first step of presetting a value of the above-mentioned constant, increasing a predetermined value of the phase little by little, and storing a value at which the difference between a position of the above-mentioned servomotor and the position command of the position command generation means becomes small in storage means as an optimum value of the above-mentioned phase;

and then

executing a second step of previously increasing the value of the above-mentioned constant little by little and storing a value at which the difference between the position of the above-mentioned servomotor and the position command of the position command generation means becomes small in storage means as an optimum value of the above-mentioned constant.

3. The servo control system as claimed in claim 1 wherein

the above-mentioned constant is a reciprocal of a position control gain in the above-mentioned servo system.