Automatic Kinematic Modelling of Robot Manipulators and Symbolic Generation of their Inverse Kinematics Solutions

Abstract

The increasing use of robot simulation systems has raised the need for a full kinematic treatment for a large number of different types of robots. Usually this is done either by supplying a general iterative inverse procedure, a time-consuming method not guaranteed to converge, or by carrying out a special analysis for each type. In this paper we present a software system whose input is an elementary geometric description of a robot. The system automatically builds the Denavit-Hartenberg model out of the input, while retaining information of how to interface between the built model and the elementary description. It then derives the equations of the inverse kinematics and subsequently solves them symbolically in closed form (if possible). The solution is accurate, efficient in on-line use, gives all possible solutions for every input frame of the end-effector and is thus suitable for use in robot simulation. Our software package was incorporated into the ROBCAD* simulation system where it has been successfully modelling and solving a myriad of kinematic structures of robots and other mechanisms.