IMU-based Online Kinematic Model Parameter Estimation for Four-Wheeled Skid-Steering Mobile Robot Desired Motion Tracking on Different Terrains

This work presents an online adaptive tracking control for a 4-wheel skid-steering mobile robot (SSMR). The objective is to develop an online kinematic model parameter estimation for an equivalent differential drive kinematic model, enabling motion control on the various terrains’ conditions. Combined with an equivalent differential drive kinematic model, the angular velocity of robot motion analyzed by the inertial measurement unit (IMU) sensor is used as the observation quantity, and the steering efficiency parameters in the kinematic model are automatically adjusted by a proportional derivative (PD) controller to improve the desired motion tracking control performance for the robot in the face of different terrains. The execution of tracking control is achieved by the SSMR with torque-adjusted 4-wheel independent velocity control. The proposed strategy is validated experimentally, where the SSMR performs the desired motion tracking in 10 sets with four types of terrains with different levels of flatness. The results demonstrate the high potential in overground navigation settings, due to its fast adaptation and motionfollowing capacity.