Trajectory Tracking of Tracked Robot Using Super Twisting Algorithm With Enhanced Boundary Layer and Dynamics Incorporating Gravity Center Offset

In the research on trajectory tracking control of tracked mobile robot (TMR), it is commonly assumed that the center of gravity and the geometric center are equivalent. However, in practical scenarios, there often exists a phenomenon of center of gravity displacement caused by loads. This article establishes the steering kinematic and dynamic models for TMRs, specifically addressing the effects of nonlinear disturbances such as center of gravity displacement and slip. It also clarifies the multi-input and multioutput attributes inherent in this class of underactuated systems. Additionally, the article formulates dynamic differential equations with linear velocity and angular velocity as state variables in order to separate the system inputs. During the design process of the trajectory tracking controller, the control velocity and control angular velocity are initially determined using the backstepping method. Subsequently, in order to address the chattering phenomenon of trajectory tracking state, an enhanced boundary layer super-twisting algorithm with fuzzy logic were introduced. To assess the efficacy of the proposed approach, a comprehensive evaluation is carried out through a combination of numerical simulations and real experiments. The results demonstrate the effectiveness of the enhanced approach in inherently reducing the chattering phenomenon without sacrificing tracking accuracy.