A new architecture for direct drive robots

A practical architecture, using a four-bar-linkage, is considered for the University of Minnesota direct-drive robot. This statically-balanced direct-drive robot has been constructed for stability analysis of the robot in constrained manipulation. As a result of the elimination of the gravity forces (without any counterweights), smaller actuators and consequently smaller amplifiers were chosen. The motors yield acceleration of 5g at the end point without overheating. High torque, low speed, brushless AC synchronous motors are used to power the robot. Graphite epoxy composite material is used for the construction of the robot links. A four-node parallel processor is used to control the robot. The dynamic tracking accuracy with the computed torque method as a control law has been derived experimentally