A redundantly actuated 2-DOF 3RRR PKM with flexure joints: less is more

Abstract The development of a planar manipulator with flexure joints and redundant actuation has been considered before, showing that the redundancy can be exploited to increase support stiffness reduce static actuator loads. In this previous design manipulator’s workspace defined encompass all kinematically accessible end effector positions. current paper we reconsider philosophy. It will shown limiting (“less”) ultimately results in better performance larger area (“more”). dynamic is evaluated flexible multibody model. links safely as rigid parts, but model account for nonlinear behaviour undergoing relatively large deflections. spatial beam elements implemented spacar software result numerically efficient models have proven well-suited optimisation. With such model, geometry optimised maximise while assuring minimal parasitic natural frequency local stresses throughout full workspace. Furthermore, simulations show preloading reduced torques are needed counteract finite joint compliance stationary positioning anywhere except equilibrium position effector. build validated experimentally. A control system handles by minimising 2-norm driving synthesised. demonstrated setup’s similar particular significantly lowers required torques.