Multiaxis robot having improved motion control through variable acceleration/deceleration profiling

Claim 1

A digital control for a robot having a plurality of arm joints, said control comprising: a plurality of electric motors, one motor for driving each of the plurality of robot arm joints; a power amplifier operable to supply drive current to each motor; feedback control loop means for ech joint motor including at least digital position and velocity control loops operable at a predetermined sampling rate to control the associated power amplifier; digital control means for generating position commands for said feedback control loops means in accordance with predefined moves set forth in a robot position command generating program means; said position command generating program means including planning progam means for generating for the position commands a time profile including acceleration, slew and deceleration time segments for implementing each robot program command; means for computing a slew time from a slew velocity; means for computing an acceleration time from equations for a preselected one of a plurality of acceleration profiles; means for computing a deceleration time from equations for a preselected one of a plurality of deceleration profiles; said position command generating program means further including trajectory program means for computing trajectory position commands for said feedback control loop means in accordance with the time profile applicable to the current move segment; said trajectory program means computing said position commands from the preselected acceleration profile equations during acceleration and from the preselected deceleration equations during deceleration.