Optimal design of a micro parallel positioning platform. Part I: Kinematic analysis

Using a coarse-and-fine actuator combination (dual stage system), a new design of the three degree-of-freedom (DOF) micro parallel positioning platform with high mobility, high accuracy, and a large working space is proposed. To achieve these three DOFs and implement the dual stage system, there are six possible architectures for the coarse and fine actuators, respectively. This paper is organized in two parts. Part I treats the kinematic analysis of each architecture and the problem of selecting the correct coarse actuator architecture. Inverse kinematics and Jacobian matrices for six types of coarse actuator architectures are derived and one proper coarse actuator architecture is selected based on the mobility (rotational capability) analysis, condition number evaluation of the Jacobian matrix, and manufacturability consideration. Part II on real machine design will follow in the next issue of Robotica.