Model Predictive Control for Wheeled L-quadruped Robots Based on Hierarchical Decoupling
The wheeled-quadruped hybrid robot is an innovative composite robot platform that combines the features of legged and wheeled robots,enabling three modes of movement:fast wheel motion,legged obstacle-crossing,and wheel-leg combination.A control method for wheeled-quadruped robot based on linear model predictive control(MPC)is proposed to achieve the above three maneuvering modes.The MPC-based control method employs a hierarchical framework to separate the wheel speed control from the quadruped stability control.It independently controls the wheel speeds and estimates the torques while compensating for wheel-ground disturbances in real-time.For body stability control with MPC,the control model is converted into Ax+Bu standard form using state augmentation.Gravity acceleration is used to equivalently transform the end-effector force disturbances,allowing the external force disturbances to be integrated into the dynamic model without increasing the system's state space dimension.In the simulation and practical test on Panda-W wheeled-quadruped robot,the proposed algorithm effectively mitigates the wheel-ground disturbances during wheel-leg acceleration and deceleration,achieving stable body control and successful Trot gait locomotion on various terrains.
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维普
