Parallel algorithm and VLSI architecture for a robot's inverse kinematics

The inverse solutions of a robotic systems are generally produced by a serial process. Due to the computing time of processing geometry data and generating an inverse solution corresponding to a specified point in Cartesian trajectory is larger than the sampling period, the missing points in the joint space are generated by some interpolation schemes (linear or cubic spline interpolations) between two inverse solutions. The dynamic errors are therefore introduced. Obviously this kind of dynamic errors can be eliminated, if the computational time of generating the inverse solutions and processing geometric information can be less than the sampling period. The dynamic errors are increased when a robot's speed is increased by using the available schemes. For a high speed and high performance robot, the dynamic errors can be significant. In this paper, a parallel algorithm for a robot's inverse kinematics is derived and corresponding VLSI architectures are presented. This algorithm can also be implemented by using multiprocessors. By using the proposed parallel algorithm, it is believed that the dynamic errors can be reduced significantly or even eliminated if the computing time of processing geometric data can be reduced significantly by using the technique of parallel processing.