A Model-Based Control Framework for a Novel Combined Octopod Robot

The legged robot with a waist structure has a more flexible body structure than that with a rigid body. To address the complexity of the waist structure, this paper proposes a lightweight combined octopod robot consisting of two quadruped robots connected back and forth by a novel detachable docking mechanism. To address the issue of performance loss caused by model predictive control (MPC) in high-dimensional nonlinear systems of octopod robots, a centralized control framework for nonlinear model predictive control (NMPC) and whole body control (WBC) is proposed to optimize the contact forces and joint torques. Apart from that, an attitude adaptation control strategy is designed in order to improve the traversing capability in the steep slope terrain. The combined octopod robot platform and motion control framework have been evaluated through a series of experiments, and the results show that the robot has excellent omnidirectional motion capability, as well as strong terrain adaptability and traversing ability in sloping terrain.