Contour Error of the 3-DoF Hydraulic Translational Parallel Manipulator

The paper deals with a selected problem of contour error for the desired tracking trajectory of the spatial 3-DoF hydraulic translational parallel manipulator (TPM). The prototype hydraulic TPM consists of a fixed base and a moving platform, that are connected by the joints with three hydraulic linear axes. The closed-loop kinematic chains of the hydraulic TPM create structure 3-RRPRR, in that revolute joints R and prismatic joints P step out. The three equal integrated electro-hydraulic axes are prismatic joints P, in that hydraulic cylinders are integrated with position measuring systems and proportional directional control valves.