Tracking Control and Experiment for Propeller-Driven Wall-Climbing Robot Considering Actuator Dynamics and Saturation

In this paper, an adaptive tracking controller for the propeller-driven wall-climbing robot is developed, which is subject to velocity-related input saturation and velocity constraint. First, the model of the propeller-driven wall-climbing robot is established, where actuator dynamics and input saturation are considered with velocity constraints. The strategy of active gravity balance is put forward, which simplifies the modeling but leads to the problem of velocity-related input saturation. Second, the Gauss integration function is used to approximate the velocity-related input saturation. The velocity constraint would be handled by employing the barrier Lyapunov-based transformation rather than the barrier Lyapunov function (BLF) method. Thirdly, the tracking controller is developed based on the dynamic surface control method, where the adaptive robust controller and neural networks are combined to deal with unmodeled dynamics and external disturbances. According to the Lyapunov stability theory, it is proved that the propeller-driven robot system will be stable under the developed controller, while signals in the closed-loop system are ultimately uniformly bounded. Finally, simulation results show the effectiveness of the proposed tracking control scheme.