Pressure Control of Multi-Mode Variable Structure Electro-Hydraulic Load Simulation System.

Area of Science:

• Control Systems Engineering
• Hydraulic Systems
• Robotics

Background:

• Electro-hydraulic load simulation systems face significant position disturbances during operation.
• Model parameter uncertainty and external disturbances impact system performance.
• Existing systems require improved methods for disturbance rejection and precise control.

Purpose of the Study:

• To propose a nonlinear multi-mode variable structure independent load port electro-hydraulic load simulation system.
• To develop an integral sliding mode active disturbance rejection composite control strategy for fixed-time convergence.
• To accurately estimate and compensate for lumped disturbances using an extended state observer.

Main Methods:

• Treating model parameter uncertainty and external disturbances as lumped disturbances.
• Designing a nonlinear multi-mode variable structure system for specific loading conditions.
• Integrating fixed-time integral sliding mode and active disturbance rejection control algorithms within an extended state observer framework.

Main Results:

• The composite control strategy achieved high pressure control accuracy (99.76%-99.94%) under various disturbance frequencies and signal types.
• The extended state observer effectively estimated lumped disturbances and compensated for them.
• Sensor random noise influence was within acceptable limits, demonstrating effective filtering.

Conclusions:

• The proposed control strategy significantly improves the precision of electro-hydraulic load simulation systems.
• The system demonstrates robustness against disturbances and noise.
• This research provides a foundation for advanced collaborative control and engineering applications.