Optimal energy-saving controller design for an electro-hydrostatic actuator integrated into a wheel loader

Electrifying non-road mobile machinery is vital for reducing emissions and improving energy efficiency. Replacing conventional hydraulic systems with electro-hydrostatic actuators is a key step in this transition. However, developing controllers that ensure dynamic performance, energy efficiency, and thermal management remain challenging. This paper proposes an optimal energy-saving controller, LQFFRO, for an EHA integrated into a wheel loader. The LQFFRO minimizes energy consumption and improves thermal performance while maintaining precise trajectory tracking under varying loads. Simulation results show that LQFFRO achieves tracking accuracy comparable to a PID controller, with position errors within 3 mm, while significantly reducing peak current and voltage. It also lowers the electric motor’s temperature by 2.5°C and reduces energy consumption by 0.395 kJ per cycle, leading to annual energy savings exceeding 2.84 million kJ compared to PID. Lyapunov-based analysis confirms the closed-loop system’s robustness under disturbances. These results confirm that LQFFRO controller effectively balances dynamic performance, energy efficiency, and thermal stability, contributing to the reliable and sustainable electrification of non-road mobile machinery.