US 4,916,375 A · Servomotor control apparatus

Abstract

The invention is a servomotor control apparatus for controlling the positioning of a movable element of an industrial robot or NC machine tool. An NC unit or a robot controller detects displacement from a movable element that is to be positioned, such as a table, forms a position command regarding a servomechanism, and has a correction circuit (A) which receives quadrant data (BLF) regarding a backlash correction command. When there is a quadrant reversal for each axis of the movable element, frictional torque corresponding to the axis is stored and a torque correction command (FR) corresponding thereto is outputted. A torque command of a fully-closed loop servo system for performing control based on a fed back position detection signal is corrected by the torque correction command. The servomotor control apparatus can be applied to semi-closed loop servo system in which a backlash correction is possible, and not just to a fully-closed loop servo system.

Claims6

Dependent claims

A servomotor control apparatus for controlling movement of a mechanical load in response to a position command and to a backlash correction command for correcting backlash at the mechanical load, comprising:

position detecting means for detecting a position of the mechanical load;
discriminating means for discriminating, based on the backlash correction command, a time at which an operating quadrant of the mechanical load reverses;
correcting means for receiving offset data corresponding to frictional resistance of the mechanical load, and for generating a corrected torque command based on the offset data, the detected position and the position command when the quadrant reverses;
and
control means for driving and controlling the mechanical load based on the corrected torque command.

2 more elements

Dependencies are inferred from the claim text.

Servomotor control apparatus

Life of this patent

Servomotor control apparatus

Life of this patent

Abstract

Claims6