Linear Estimation of the Odometric Parameters for Differential-Drive Mobile Robots

Abstract

In this paper a calibration technique aimed at identifying the odometric parameters of differential-drive mobile robots is proposed. The proposed algorithm is based on two successive least-squares estimations based on the continuous-time kinematic equations of motion; the time-discretization error, thus, is avoided. The use of the least-squares technique is made possible by observing a linear mapping between the unknowns and the measurements and it is not the results of a linearization. Another advantage of the proposed technique is that no predefined path is required, i.e., the robot can move under a preferred navigation algorithm. The basic technique makes use of video-camera measurements and absolute position readings of the wheels' encoders, the use of different sensors and measurements of the wheels velocities is also discussed. Experimental results with the mobile robot Khepera II confirm the effectiveness of the proposed technique