Off-Line Calibration of Autonomous Wheeled Mobile Robots

Abstract

Wheeled mobile robots (WMRs) are very interesting regarding different applications from in-house activities in assisting elderly people and patients to space exploration. While the design concept and the application of the WMRs determine specifications of the robot, the positional errors occur during the WMR motion. The positional errors are inevitable, as they are caused by imperfections in design to fabrication; therefore, there is a need to rectify them using calibration techniques such as odometry, camera-based error detection, or using gyroscope and compasses. This chapter focuses on the use of odometry as it provides improved short-term accuracy with high sampling rates while it is more economical and requires fewer landmarks to localize the WMR. The context provides an overview of WMRs mechanisms, differential and omnidirectional drive, and then introduces an odometry-based method to correct the motion of both types of WMRs. Experimental results on four robots exhibited that positional error was significantly improved. Using analysis of variance (ANOVA) test, the authors could not detect any change in error improvement when the robot changed.