Kinematical Model-based Yaw Calculation for an All-Terrain Mobile Robot

Wheeled mobile robots have been widely investigated and put into many applications such as planet surface exploration fields and other rough terrain situations. Yaw calculation is of importance for mobile robots to autonomously navigate and control. Sensor-based methods for calculating robot's yaw found their limits in the situations where sensor data are not sufficiently applicable or badly noised, especially for planet exploration robots. This paper proposed a novel model-based method for yaw calculation of an all-terrain mobile robot with passively compliant mechanisms. The robot's kinematical model is built considering wheel slips and the physical wheel-terrain contact relationship. Treating the all-terrain mobile robot as a series-parallel multi-body system, we can directly build the robot's kinematical model based on closed velocity chain theory. The yaw calculation can be easily finished by detecting wheel encoder data and solving the kinematical model of the robot. Several experiments were performed to test the validity and usefulness of this method. This kinematics-based yaw calculation method also proved its robustness and real-time performance.