Research on Power Matching and Energy Optimal Control of Active Load-Sensitive Electro-Hydrostatic Actuator

Abstract

Electro-hydrostatic actuator (EHA) is an important type of power-by-wire (PBW) which is a highly integrated closed volume control system with the advantages of high reliability, high efficiency and easy maintenance. However, under heavy load conditions, a large amount of heat the EHA motor produces affects the system's working time and even the system life, which restricts the widespread application of EHA systems. In order to solve the problem of motor heating and the contradiction between high dynamics and high efficiency of the EHA system, a novel active load-sensitive principle and structure of EHA system is proposed based on the load-sensitive principle. The active load-sensitive EHA (ALS-EHA) is a dual control variable system consisting of a motor pump main loop and a load-sensitive loop. As for the latter, the system load pressure is introduced into a special designed and optimized pressure fellow valve (PFV). The valve outlet is connected to the plunger pump swash plate variable mechanism. The EHA pump displacement is actively adjusted by controlling the current input to PFV. The two-degree-of-freedom cooperative control for the output flow of the pump can be implemented by adjusting the motor speed and the pump displacement. An energy optimal robust control law based on fuzzy and disturbance compensation is presented for the control architecture. The simulation results show that the ALS-EHA system based on the control law proposed in this paper can effectively reduce the motor heat while ensuring the dynamic performance of the system.

Power-Sensitive Early Warning Data Conversion Method Combined with Multiobjective Differential Evolution Algorithm

“…e estimated value of the specific motion model data of the power-sensitive early warning can be calculated using formula (16):…”

“…At the same time, the conversion of the power-sensitive data on early warning can be acquired as soon as possible; and "restart upon failure" is an example where no early warning can be issued upon failure, which can be secured by using multiple entities. Hence, the data information on "restart upon failure" in the process of conversion of power-sensitive data can be deemed as an NER target object task; and finally, the extraction of the sensitive data information on its point force can be implemented [16,17].…”

Load sensitive control characteristics of a novel two-dimensional pulse width modulated variable mechanism

“…Other scholars have innovated variable mechanisms, Huang et al 14 designed a pressure assist valve in the variable mechanism of a load sensitive pump to actively sense changes in load pressure and apply the changed pressure to a variable cylinder, thereby achieving control of pump displacement. Chao et al 15 proposed a load sensing pump specifically designed for the electro-hydrostatic actuator, which works together with a spool valve and a linear spring to modify the pump’s volumetric displacement.…”

Optimal Design of Motor–Pump Parameters for Direct Load-Sensitive EHA Based on Multi-Objective Optimization Algorithm

“…The EHA is now widely used in many fields such as aerospace and construction machinery [4][5][6]. The EHA can be categorized into a variety of configurations depending on the form of motor speed and pump displacement change, including the fixed displacement pump and variable speed motor-EHA (FPVM-EHA), variable displacement pump and fixed speed motor-EHA (VPFM-EHA), variable displacement pump and variable speed motor-EHA (VPVM-EHA) [5,7,8]. Among them, the direct load-sensitive EHA (DLS-EHA) is realized by introducing load-sensitive technology on the basis of VPVM-EHA.…”