GA-Based Modeling for a Parallel-Link Coordinate Measuring Machine

Measurement model of parallel-link CMM is equated with the solution of forward kinematic. Forward kinematic is high-order nonlinearity multi-solution problem. It is very difficult to find the solution of forward kinematic for a parallel mechanism. This paper introduces a GA-based modeling method for 6-SPS type parallel-link CMM. Firstly, the inverse kinematics mathematic model of parallel-link CMM is established in this paper. Then the solution of forward kinematics is obtained by improving the fundamental genetic algorithm, which overcomes the shortcoming of analytical method and numerical method, and receives very good effect. This solution simplifies forward kinematics, and provides an essential theoretical basis for development the parallel-link CMM.