Pump-valve Compound Control Performance of D+A Combined Multi-pump Controlled System

doi:10.3901/JME.2018.20.304

Abstract

Abstract: Due to the mismatch between the pump output and the load flow demand in the traditional high-power multi-pump hydraulic valve controlled system, the hydraulic system transmission efficiency is low. Based on the concept of PCM control of digital pump, a hydraulic control system combined with digital and analog control is proposed. Through the flow area division method, the configuration principle of this system is given, in which the fixed pumps' displacement ratio uses a binary-coding, and the step flow difference of the fixed pump is compensated by 1 variable pump. The flow state matrix of this system is established, and the control signals of pumps are obtained through solving this matrix. In order to reduce the control characteristics impact of the system due to the step flow, a pump-valve compound control strategy is proposed, and the output characteristics of the system are tested under this control strategy. The results show that under this control strategy, the multi-pump hydraulic system has good dynamic and static characteristics, as well as an energy saving effect. The sinusoidal displacement tracking accuracy is up to ±0.1 mm with a lag of approximately 100 ms. Due to the use of D+A combined flow control and proportional relief valve pressure control, the output flow and pressure of the multi-pump hydraulic system are always higher than the load required flow of 10 L/min and the load required pressure of 2 MPa, respectively. So that the overflow and throttle losses of the system are greatly reduced.

Key words: D+A, hydraulic system, multi-pump, pump-valve compound*

CLC Number:

TH137

CAO Xiaoming, GUO Baofeng, WANG Pei, YAO Jing. Pump-valve Compound Control Performance of D+A Combined Multi-pump Controlled System[J]. Journal of Mechanical Engineering, 2018, 54(20): 304-311.

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