Sliding-Mode-Based Active Disturbance Rejection Control for Self-Balancing Transport Vehicle

The sliding-mode-based active disturbance rejection control (ADRC) strategy for self-balancing transport vehicle is discussed in this paper. First, we develop a mathematical model of the self-balancing transport vehicle through force analysis and formulate the control objective as maintaining the pendulum vertically while regulating the cart position. Next, we introduce a class of hyperbolic tangent (tanh) function into tracking differentiator, which has easier parameter adjustment, response fast, and good filtering capability. Then, we propose a power-exponential reaching law with tanh function and design the sliding-mode (SM) extended state observer. And then, we combine ADRC strategy with sliding-mode control (SMC) to design SM nonlinear state error feedback based on the proposed reaching law. This strategy improves the accuracy of observer estimation, reduces chattering, and enhances the robustness. Finally, the proposed strategy is applied to the self-balancing transport vehicle and the simulation results demonstrate its feasibility and effectiveness.