Robot control process

Claim 1

A process of controlling a robot having a direct drive section, a motor for directly driving said direct drive section, an encoder for detecting a motion of said direct drive section driven by said motor so as to deliver pulses, a motor driver for controlling the motion of said motor, an up-and-down counter for counting pulses from said encoder so as to deliver a count value, a subtractor for subtracting said count value from a position command value delivered from a position command section so as to deliver a digital positional deviation value, a converter for converting said digital positional deviation value into an analog value, and a variable gain amplifier for amplifying said analog value so as to obtain a motion instruction adapted to be delivered to said motor driver, comprising the steps of: comparing said digital positional deviation value with a threshold value so as to determine whether said digital positional deviation value is greater than said threshold value or not; multiplying said digital positional deviation value by a number which is greater than zero before the digital positional deviation value is subjected to digital-analog conversion in accordance with a result of said comparing step; converting said multiplied digital positional deviation value into an analog value; and amplifying said analog value; and amplifying said analog value with a gain depending upon said result of said comparing step.