Motion Drive and Multi-mode Control Method of an Electric Parallel Six Wheel-Legged Robot

A parallel six wheel-legged mobile robot is proposed. The robot adopts a multi-mode Stewart leg structure with large load capacity, which integrates the advantages of wheeled motion and legged motion, and can realize legged, wheeled and wheel-legged compound motions. Firstly, the design idea of the robot is described, and the hardware system and control system of the electric parallel six wheel-legged robot are designed. Secondly, a complete set of legged "triangle" gaits and a stable walking algorithm are designed for the legged motion mode, which can reduce the vertical impact between the foot and the ground, and prevent foot motion from dragging or skidding. For the wheeled motion mode, the principles of cooperative control and steering of 6 wheels are designed and introduced. For the wheel-legged compound motion mode, the principles of variable height, variable support surface, variable wheel track and active vibration isolation controls are introduced with the analysis emphasis on active vibration isolation control and variable wheel track control, which can realize active vibration isolation and attitude stabilization control, and improve the stability of the wheel-legged compound motion of the robot on rough terrain. Finally, the legged, wheeled and wheel-legged compound motion modes of the electric parallel six wheel-legged robot are tested. The experimental results verify the feasibility of the design of the parallel six wheel-legged mobile robot and the effectiveness of the driving and control algorithm of each motion mode.