Robust Tracking Control of Wheeled Mobile Robot Based on Differential Flatness and Sliding Active Disturbance...

Area of Science:

• Robotics
• Control Systems Engineering
• Mechatronics

Background:

• Wheeled mobile robots (WMRs) face significant challenges in maintaining stable tracking due to external disturbances like wind and internal uncertainties such as wheel slip.
• Traditional control methods, including sliding mode control (SMC), often suffer from chattering and reduced robustness when dealing with complex, unmodeled dynamics.

Purpose of the Study:

• To develop a robust tracking control strategy for WMRs that effectively mitigates the effects of wind disturbances and wheel slip.
• To enhance the stability and tracking performance of under-actuated WMRs in uncertain environments.

Main Methods:

• Differential flatness methodology was employed to transform the nonlinear WMR model into a linear canonical form.
• A hybrid control approach integrating boundary layer sliding mode control (SMC) with active disturbance rejection control (ADRC) was proposed.
• An extended state observer within ADRC was utilized to estimate and compensate for lumped uncertainties.

Main Results:

• The proposed integrated control method demonstrated effective suppression of chattering while maintaining robust tracking performance.
• Simulations and experimental results validated the superior efficiency of the proposed controller compared to existing methods.
• Lyapunov theory was used to establish the stability properties of the closed-loop system.

Conclusions:

• The combined SMC-ADRC approach offers a practical and robust solution for WMR tracking control under significant uncertainties.
• This method significantly improves the WMR's ability to perform accurate tracking tasks in challenging, dynamic environments.
• The integration of ADRC with boundary layer SMC provides enhanced disturbance rejection and control accuracy.