Complete model-free siding mode control (CMFSMC).

Area of Science:

• Control Engineering
• Nonlinear System Dynamics
• Robotics

Background:

• Model-free control is crucial for systems with unknown dynamics.
• Sliding mode control (SMC) offers robustness but often requires system models.
• Existing model-free approaches have limitations in handling complex nonlinearities.

Purpose of the Study:

• To develop a complete model-free sliding mode control (CMFSMC) framework.
• To enable control of continuous-time non-affine nonlinear dynamic systems with unknown models.
• To bridge the gap between model-based and model-free SMC designs.

Main Methods:

• Introduction of two novel equalities to assign sliding function derivatives.
• Design of a double SMC (DSMC) without plant models.
• Development of a model-free state observer and a desired reference state vector design.
• Incorporation of U-model based control (U-control) for system configuration.

Main Results:

• The CMFSMC framework successfully controls nonlinear systems without requiring plant nominal models.
• The U-control configuration effectively uses DSMC as a dynamic inverter and a model-free observer.
• Simulated case studies validate the framework's performance and transparent design procedure.

Conclusions:

• The presented CMFSMC framework provides a robust and model-independent solution for controlling complex nonlinear systems.
• The design methodology is transparent, facilitating practical applications and future expansions.
• The study demonstrates the feasibility of achieving precise system performance without prior knowledge of system dynamics.