End-point control of a two-link manipulator with a very flexible forearm - Issues and experimentsFor mechanical manipulators, a logical sensor location is at the manipulator end-point where tasks are performed. Unfortunately, when bending flexibility exists between an end-point sensor and a joint actuator, stability and performance are achieved only through sophisticated control design. Some of the issues involved in utilizing end-point sensing for two-link flexible manipulators are addressed. A modeling technique that properly represents the foreshortening of a flexible link undergoing deflections is presented. In order to realize fully the advantages of the assumed-modes modeling method, mode shapes are selected that allow a low-order model to be used effectively for simulation and control purposes. A nonlinear controller, incorporating state feedback and a constant-gain extended Kalman filter driven by end-point measurements, is designed and compared to a conventional proportional-plus-derivative controller that uses collocated sensors. Results from implementing these controllers on the experimental Stanford multilink flexible manipulator are given.
Document ID
19890066658
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Oakley, Celia M. (Stanford Univ. CA, United States)
Cannon, Robert H., Jr. (Stanford University CA, United States)