It is well known that conventional robot manipulators made of rigid links incorporate strongly coupled dynamics, and this situation is the source of many control problems. This difficulty is more pronounced when considering the control of flexible link manipulators. Taking into account the physical properties of flexible manipulators and their inherent vibratory behaviour it is proposed in this chapter to consider the control problem in the multivariable frequency domain. Such an approach is first introduced for analysing the coupling of a mixed rigid-flexible two-dimensional (2D) manipulator. The approach is then extended to the case of a 2D flexible manipulator. Following these analyses, a figure of merit to quantify the interaction between links is introduced, and the resultant designs for obtaining row and column dominance of both 2D manipulators are presented. Finally, an approach involving the manipulator Jacobian is proposed to define the control law. Finite element analysis is used in all cases to simulate the manipulators, and the models are experimentally validated.

Inspec keywords: control system synthesis; stability; flexible manipulators; manipulator dynamics; Jacobian matrices; multivariable control systems; frequency-domain synthesis; filtering theory; finite element analysis

Other keywords: mixed rigid-flexible 2D manipulator; row dominance; column dominance; multivariable frequency domain; strongly coupled dynamics; finite element analysis; stability; rigid links; decoupling control; link interaction; resultant design; manipulator Jacobian; flexible link manipulators; vibratory behaviour; prefilter design; robot manipulators; single loop control strategy

Subjects: Manipulators