Odometry based pose determination and error measurement for a mobile robot with two steerable drive wheels

A trigonometric method is proposed to calculate the pose (position and orientation) of a mobile robot, possessing a locomotion platform with a unique combination of two steerable and driven wheels and two caster wheels. The model of locomotion platform is derived to deliver timely and accurate odometer information from the measured drive wheel revolutions and the steering angle measurements. Non-systematic errors, mainly slippage, are detected by a new computation method based on the ratios between the two drive wheels´ incremental distances. Real-world experiments demonstrate the correctness of the proposed model and validate the ability of the algorithm to detect non-systematic errors.