Research on Motion Mode Conversion Control of Wheel-legged Biped Robot

The bipedal wheel-legged robot with auxiliary legs studied in this paper has two motion modes, two wheels and four wheels, and can transform motion modes according to operation requirements. This paper focuses on how to realize motion mode transformation control under stable equilibrium. Firstly, kinematics analysis and dynamics modeling of the robot are carried out to complete the motion description and dynamics description of the robot in Cartesian space. Then the robot is simplified into a wheeled inverted pendulum model, and the driving wheel and other parts are decoupled to analyze its dynamic characteristics. In this paper, LQR controller will be used to ensure the robot is always in a balanced state, and then priority task space control (PTSC) based on quadratic programming (QP) will be adopted to track the robot trajectory. Finally, the smooth transformation of the robot under two motion modes of two wheels and four wheels is completed by experiments, which verifies the effectiveness of the control algorithm designed in this paper.