Switched step integral backstepping control for nonlinear motion systems with application to a laboratory helicopter

Area of Science:

• Control Systems Engineering
• Robotics
• Nonlinear Dynamics

Background:

• Backstepping control is widely applied to nonlinear motion systems.
• Conventional backstepping methods can be susceptible to measurement noise and energy inefficiency.
• Improving control performance in complex systems like the twin rotor helicopter remains a challenge.

Purpose of the Study:

• To investigate and enhance the energy efficiency of backstepping control for nonlinear motion systems.
• To introduce a novel control scheme, Switched Step Integral Backstepping Control (SSIBC), to address limitations of conventional methods.
• To validate the proposed SSIBC method experimentally on a challenging system.

Main Methods:

• Development of the Switched Step Integral Backstepping Control (SSIBC) scheme.
• Implementation of a bi-state dependent hysteresis rule for stable switching between controllers.
• Experimental verification on a Multiple-Input Multiple-Output (MIMO) twin rotor laboratory helicopter.

Main Results:

• The SSIBC scheme demonstrated improved immunity to measurement noise and increased energy efficiency.
• Experimental results showed reduced power consumption, control signal saturation, and motor jerking compared to conventional backstepping.
• Significant improvements in precision and energy efficiency were observed against an optimized decoupling PID controller.
• The SSIBC exhibited robustness when subjected to external disturbances.

Conclusions:

• The proposed SSIBC is an effective control strategy for nonlinear motion systems, offering enhanced energy efficiency and robustness.
• SSIBC provides a practical improvement over conventional backstepping and PID control, particularly in noisy environments and for systems with coupled dynamics.
• The method successfully addresses limitations related to measurement noise and power consumption in practical applications.