Configuration Optimization for End-Point Stabilization of Redundant Manipulators With Base Flexibility

Abstract

This paper presents a method to determine an optimal configuration of a teleoperated excavator to minimize the induced undercarriage oscillation for robust end-point stabilization. The use of remotely operated robotic excavators for tasks such as measurement and reorganization of damaged objects at a disaster site, instead of human responders, is considered as a viable option. Treating the excavator as a kinematically redundant system, where non-unique combinations of the undercarriage position and arm posture can locate the end-point at the same reference. A specific configuration can be chosen to not excite undercarriage oscillation with simple end-point error feedback control without model-based or measurement-based vibration suppression. Robust stability measures based on normalized coprime factorization as well as modal decomposition solve the redundancy of the kinematics. An advantage of this approach is that the control engineer can proceed as if the excavator arm is fixed to rigid ground, which is practically not the case, and apply simple traditional Jacobian-based end-point control.