Method for coordinating motion control of a multiple axis machine

Abstract

A multiple axis machine includes a plurality of servo-motors that produce movement of a member in at least two axes. The servo-motors are controlled by a computer which runs a simulation of a line shaft power train for producing movement of the member. Specifically, characteristics of a line shaft for powering the machine are defined along with characteristics of a pair of mechanical linkages with dynamically variable kinematics that are driven by the line shaft to produce movement along the two axes. The computer simulates a virtual line shaft using the line shaft characteristics and produces an angular acceleration, an angular velocity and an angular position of the virtual line shaft. The computer also simulates a pair of virtual mechanical linkages with dynamically variable kinematics based upon the linkage characteristics, and based on the angular acceleration, angular velocity and angular position of the virtual line shaft. The simulations produce control signals that operate actuators for each axis of the machine, and produce dynamically variable kinematic feedback force signals which are applied to the simulation of the virtual line shaft to simulate dynamically variable kinematic forces exerted by the mechanical linkages on the virtual line shaft.