Position control apparatus for machine tool with fuzzy compensator
AssigneeLG Industrial Systems Co., Ltd.
InventorsJong-Hwan Kim, Jeong-Yul Jeon
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Abstract
A position control apparatus for a machine tool such as an SMD-mounter which is capable of moving a head to a desired position in as rapid a time as possible, by estimating a moving position of the head according to an evolutionary computation algorithm, and a friction of a guiding unit for guiding the head and the movement of the head.
Claims6
A position control apparatus for a machine tool, comprising:
- a pre-unit fuzzy compensator for outputting a fuzzy-compensated signal according to an evolutionary computation algorithm after obtaining an error and a rate of a change of the error from a positional feedback output signal from a machine tool positioning system;
- a proportional-derivative controller for carrying out a proportional-derivative control and outputting a torque value after obtaining an error from an output signal from the pre-unit fuzzy compensator and the output signal from the system;
- and
- an actuator for multiplying the torque value by a predetermined coefficient to obtain a control signal and outputting the control signal to the system.
A position control apparatus for a machine tool, comprising:
- a pre-unit fuzzy compensator for outputting a fuzzy-compensated signal according to an evolutionary computation algorithm after obtaining an error and a rate of change of the error from an input positioning signal and an output positional feedback signal from a machine tool positioning system;
- a proportional-derivative controller for carrying out a proportional-derivative control and outputting a torque value after obtaining an error from an output signal from the pre-unit fuzzy compensator and the output signal from the system;
- and
- a friction compensator for receiving the output signal from the system to operate a parameter with respect to friction, estimating friction of the system from the parameter according to the evolutionary computation algorithm and compensating for it;
- and
- an actuator for multiplying torque value outputted from the friction compensator by a predetermined coefficient to obtain a control signal and applying the control signal to the system.
The apparatus of claim 6, wherein the parameter estimating unit models the friction from a movement equation and from the modeled friction, estimates the eight parameter vectors:
- z=m, F.sub.c, F.sub.v, F.sub.s, F.sub.s,00, k.sub..tau., x.sub.s, .tau..sub.L, .gamma.!.sup.T, z.epsilon.IR.sup.8
- wherein m represents an equivalent mass of a moving portion, F.sub.c a coulomb friction, F.sub.v a viscous friction, F.sub.s a Stribeck friction, F.sub.s,a a Stribeck friction of a static moment, F.sub.s, 00 a Stribeck friction after a long static condition, k.sub..tau. a stiffness in a static condition, x.sub.s a characteristic speed of the Stribeck friction, .tau..sub.L a friction delay time, t.sub.2 a dwell time and .gamma. a parameter of an increasing static friction.
Dependencies are inferred from the claim text.