Pre-compensated load sensing system based on speed sensitive variable pressure margin control

Abstract

The green transformation and electrification development of construction machinery have put forward higher performance requirements for load sensing systems. To address the problems of energy waste caused by the fixed pressure margin setting of existing load sensing systems and the inability to meet the flow demand of different working conditions, a pre-compensated load sensing system based on speed sensitive variable pressure margin control is proposed, and the control strategy for anti-flow saturation and speed sensitive variable pressure margin is formulated. Simulations are conducted in AMESim and a test rig is built for experimental studies. The research results indicate that: 1) the proposed system has good anti-flow saturation characteristics; 2) The proposed system can adjust the target pressure margin of the system to obtain variable flow gain according to the change of motor speed, which has better fine-tuning characteristics and flow control characteristics compared with the LUDV system; 3) Compared with the LUDV system, the proposed system reduces energy consumption by 5.0 % and 10.7 % respectively under medium and low speed conditions with a single actuator.