Identification of the Inertial and Geometric Parameters of Stäubli Robots

2 Introduction A robot is an automatically controlled, reprogrammable, multipurpose mechanical system with several degrees of freedom, which may be either fixed in place or mobile. It has been widely used so far in various industrial automation applications. The control and simulation of robots requires the development of different mathematical models. Several levels of modeling - geometric, kinematic and dynamic - are needed depending on the objectives, the constraints of the task and the desired performance. Obtaining these models is not an easy task. Using these models in control and simulation requires efficient and easy-to-use algorithms to estimate the values of the geometric parameters and the dynamic parameters of the robot. The design and control of a robot requires the computation of some mathematical models such as:  transformation models between the joint space and task space. These transformation models are very important since robots are controlled in the joint space, whereas tasks are defined in the task space. Two classes of models are considered: direct and inverse geometric models, which give the location of the end-effector as a function of the joint variables of the mechanism and vice versa; and direct and inverse kinematic models, which give the velocity of the end-effector as a function of the joint velocities and vice versa;  dynamic models giving the relations between the input torques or forces of the actuators and the positions, velocities and accelerations of the joints. In recent literature for robots, the dynamic models are required in most of the advanced control schemes. Certain criterion namely precision, performance, stability depends on the accuracy of the parameters which describes the dynamic model. Furthermore these values are necessary to simulate the dynamic equations. The dynamic model of robots plays an important role in their design and operation [1].