Consequences of Geometric Imperfections for the Control of Redundantly Actuated Parallel Manipulators

摘要: Actuation redundancy increases and homogenizes the kinematic dexterity stiffness as well force distribution among actuators of parallel-kinematics machines (PKMs). It also allows for internal prestresses within PKM without affecting environment that can potentially be used to account secondary tasks, such active backlash-avoiding control. However, in presence geometric uncertainties, this feature become a serious problem, since then, control forces may annihilated, or even some intentional prestress components interfere with environment. While model uncertainties generally tackled robust-control concepts, actuation impedes use established schemes. The effect applicability standard model-based schemes are analyzed paper. is shown lead parasitic perturbation cannot compensated by adjustment controls. An amended version augmented PD computed torque-control scheme proposed does not suffer from effects.