Cascaded adaptive integral backstepping sliding mode and super-twisting controller for twin rotor system using bond...

Area of Science:

• Robotics and Control Systems
• Mechanical Engineering
• System Dynamics

Background:

• Twin-rotor systems (TRS) exhibit complex nonlinear dynamics with coupled yaw and pitch motions.
• Accurate modeling and robust control are essential for stable operation and precise trajectory tracking in TRS.
• Existing controllers often struggle with unmodeled dynamics and external disturbances.

Purpose of the Study:

• To develop a robust cascaded controller for a twin-rotor system (TRS) using a bond graph (BG) model.
• To enhance control performance by addressing slow yaw/pitch dynamics and fast electromechanical actuator dynamics.
• To improve robustness against unmodeled dynamics and external disturbances.

Main Methods:

• A bond graph (BG) model was created to capture all energetic and dynamical couplings in the TRS.
• An adaptive integral backstepping sliding mode (AIBSM) controller was designed for the outer loop (yaw/pitch).
• A higher-order sliding mode (HOSM) observer-based super-twisting algorithm (STA) controller was implemented for the inner loop (actuators).
• An unscented Kalman filter was used for state estimation.
• Lyapunov stability analysis was performed for all controllers.

Main Results:

• The AIBSM controller effectively reduces chatter using an adaptive switching gain law.
• The cascaded controller demonstrates robustness against unmodeled dynamics and external disturbances.
• Simulations and experiments validate superior performance in trajectory tracking and disturbance rejection compared to existing controllers.

Conclusions:

• The proposed robust cascaded controller offers significant improvements for twin-rotor systems.
• The adaptive control strategy enhances stability and reduces control signal discontinuities.
• The developed BG model and control approach provide a reliable framework for TRS applications.