Design, modeling and manufacture error identification of a new 6-degree-of-freedom (6-DOF) compliant parallel manipulator

Abstract. This paper introduces a new 6-degree-of-freedom (6-DOF) compliant parallel manipulator featuring a 6-prismatic, spherical, spherical (6-PSS) configuration, leaf spring compliant joints and manufacture error identification techniques, which collectively enhance motion accuracy, motion range and dynamic performance. The 6-PSS configuration allows actuators to be mounted on the base frame rather than on the moving parts of the manipulator, thereby improving their dynamic performance. The use of leaf spring compliant joints offers superior accuracy over traditional rigid joints due to the absence of backlash and provides a relatively large motion range compared to typical compliant joints with lumped compliance. The kinetostatic models of these compliant joints have been derived and closely align with the finite-element model, exhibiting an average difference of approximately 5.5 %. Additionally, a kinematic model of the whole manipulator has been formulated and, based on it, a manufacture error identification model has been established to identify the manufacture errors, which is crucial for improving the motion accuracy. The Levenberg–Marquardt optimization algorithm is utilized to solve the identification model, with the results verified through finite-element analysis. The proposed 6-DOF compliant parallel manipulator shows great promise for applications in precision engineering, such as optical guidance and chip packaging.