Prediction of the pose errors produced by joints clearance for a 3-UPU parallel robot

This paper deals with the singularity analysis and modeling of the effects of the clearance in the joints on the parallel robot accuracy. This model is presented in an analytical form, which allowed us to predict easily the pose error for a given external load, a nominal pose and the structural parameters of the 3-UPU parallel manipulator. Based on this model, we also developed an algorithm to map the pose error within the workspace of the robot.