Backstepping Adaptive Control of Water-Based Position Servo System for
High-Speed On/off Valve Based on Extended Sliding Mode Observer
Abstract
Most mining hydraulic systems use water-based emulsions as the
transmission medium. However, the low viscosity of water-based fluids
causes leakage, making proportional flow control in water hydraulic
systems challenging and preventing precise positioning of hydraulic
cylinders. To achieve continuous flow control in water-based fluids,
this research proposes a novel backstepping adaptive controller
integrated with an extended sliding mode observer (ESMO). By using
additional pressure sensors, continuous proportional control of the
output flow of a two-stage high-speed on/off valve (TSHSV) can be
realized. The ESMO estimates the valve spool position and unmodeled
disturbances based on the current in the coil winding, and system output
flow is derived from the spool position. An adaptive controller adjusts
the spool position to control the entire system’s flow output, achieving
proportional flow control. Simulation and experimental results validate
the control accuracy of the system. The results show that the system’s
performance surpasses that of proportional valves in many respects.