DEVELOPING ACTIVE COMPLIANCE ROBOT ARMS

Abstract

A large subset of operations in which robotic arms have consistently failed to achieve their potential are those which require the robot to interact with the environment e.g. assembly, drilling, fettling. Such tasks require “force control” or “active compliance” to either control or limit the interactions. Some of these problems can be circumvented by clever mechanical design, e.g. appropriate chamfering to guide insertion, passive compliant devices. The remote centre compliance (RCC) device is the most commonly used passive compliant device. For example, an RCC device can be used to assemble a peg into a hole (a problem which confounds robots in normal operation due to position uncertainties causing linear and angular misalignment) by providing some “sprung” movement parallel to the surface into which the peg is being inserted. However, in circumstances where operation is required whilst applying desired forces and (within the constraints) arbitrarily varying the position and orientation of the tool, such solutions are inadequate.