Electrification of Construction Machinery With an Electromechanical Hybrid Implement Actuation System Using Energy-Aware Supervisory Control

Fuel-powered construction machinery performs its operational tasks through heavy-duty implements that are primarily driven by energy inefficient valve-controlled hydraulic systems. These hydraulic systems exhibit poor energy performance due to throttling losses, resulting in substantial energy waste. In this paper, an electromechanical-hydraulic hybrid implement driving system is proposed that utilize energy-efficient green electromechanical actuator (EMA) for controlling the displacement and velocity of the implement, while hydraulic cylinders-accumulator pair having high-power density is used for recovering implement’s gravitational potential energy and compensate for the limited load-bearing capacity of EMA through load sharing. A detailed simulative model of a mid-size excavator is developed, integrating multibody dynamics with cascaded, position-controlled EMA and a hydraulic sub-system. Moreover, an energy-aware mode-switching control scheme is designed, enabling the system to switch to the corresponding control mode depending upon the pre-set conditions. For energy efficiency validation of the proposed system, simulation results of boom implement’s lowering and lifting process were compared with a base-line model of hydraulic excavator grounded on load sensing (LS) system. Under identical operating conditions, the proposed greener hybrid driving system demonstrated better control performance, alongside an overall 22.5% increase in operating efficiency and a 31.4% reduction in energy consumption. The results also demonstrate energy recovery potential of such high-pollutant machinery.