Force control command synthesis for assembly using a discrete event framework

Abstract

A new discrete event controller synthesis methodology for the successful convergence of assembly tasks is presented. The modelling of an assembly process as a hybrid dynamic system has been shown to be a very effective strategy to incorporate both the continuous and discrete natures of the interaction between the workpiece and its environment. Prior works have presented controller synthesis methodologies for velocity-controlled systems (McCarragher and Asada, 1995) and here we follow a similar structure for force-controlled systems. Force control is a natural paradigm for assembly as it is fundamentally compliant. Compliance reduces sensitivity to positioning errors, which, are the most common, source of failure in assembly. A non-trivial example is given which demonstrates the effectiveness of this method.