Linear Modelling and Identification of a Mobile Robot With Differential Drive

This paper presents a modelling and identification method for a wheeled mobile robot, including the actuator dynamics. Instead of the classic modelling approach, where the robot position coordinates (x, y) are utilized as state variables (resulting in a non linear model), the proposed discrete model is based on the travelled distance increment ∆l. Thus, the resulting model is linear and time invariant and it can be identified through classical methods such as Recursive Least Mean Squares. This approach has a problem: ∆l can not directly measured. In this paper, this problem is solved using an estimate ∆̃l based on a second order curve approximation. Experimental data were colected and the proposed method was used to identify the model of a real robot.