A Fast Forward Kinematics Algorithm for 3-PRS Parallel Mechanism

Parasitic motion of 3-PRS (prismatic-revolute–spherical) parallel mechanism is discussed, inverse kinematics model of this mechanism is established. Based on the structure feature of 3-PRS parallel mechanism, a new forward kinematics algorithm for this mechanism is presented. The algorithm consists of approximate calculation and iterative calculation. The mathematical model of the proposed algorithm is clear simple, no derivative operation or Jacobi matrix inverse operation is needed, so computation is less. The experiment shows that in the same computing environment, the calculation speed of the proposed algorithm is about 2 times of the existing algorithms to achieve the same accuracy, so it can be applied to real-time control. Complexity and workload of programming is less than half of before. The algorithm is based on 3-PRS parallel mechanism, but it is also applicable for other parallel mechanism.