The Control Study of Vehicle Active Suspension with Electro-Hydrostatic Actuator

Abstract

Actuator is the key to vehicle active suspension. Based on the analyses of traditional passive suspension and active suspension system, a novel vehicle active suspension with Electro-Hydrostatic Actuator (EHA) is put forward. The system consists of two parts: spring and actuator with variable control force. The actuator is made up of hydraulic cylinder, hydraulic pump, controller and BLDCM. According to bond graph principles, bond graph model of 2 DOF passive suspensions and bond graph model of EHA active suspension are built. Moreover, fuzzy logic controller is designed and fuzzy control active suspension is simulated using MATLAB tools. The prototype and test rig of EHA active suspension are developed and bench tests are carried out. The simulation and experimental results show that fuzzy control active suspension with EHA provides better ride comfort, handling and stability than passive suspension.

Nonlinear Modeling and Coordinate Optimization of a Semi-Active Energy Regenerative Suspension with an Electro-Hydraulic Actuator

“…The system is mainly composed of a spiral spring, a hydraulic cylinder, a hydraulic motor, a brushless DC motor, a digital signal processor controller, a composite energy recovery device, and a digital potentiometer and the corresponding sensor. The hydraulic cylinder uses a double pole double-acting symmetrical hydraulic cylinder; the hydraulic motor uses a gear motor that can carry out positive inversion; and the brushless DC generator uses a permanent magnet brushless DC generator [16]. while ignoring the original design of the suspension and lacking a coordination analysis of the suspension system's damping performance and energy regenerative performance [9][10][11].…”

“…The system is mainly composed of a spiral spring, a hydraulic cylinder, a hydraulic motor, a brushless DC motor, a digital signal processor controller, a composite energy recovery device, and a digital potentiometer and the corresponding sensor. The hydraulic cylinder uses a double pole double-acting symmetrical hydraulic cylinder; the hydraulic motor uses a gear motor that can carry out positive inversion; and the brushless DC generator uses a permanent magnet brushless DC generator [16]. When the vehicle is running, the hydraulic cylinder moves with the body vibration and pushes hydraulic oil to drive the hydraulic motor to rotate, the output shaft of the hydraulic motor drives the coaxial brushless DC generator by coupling, and the generated electrical energy is recovered and stored by a composite energy recovery device to realize energy regeneration in the EHA energy regenerative suspension.…”

“…The damping force of the EHA actuator can be obtained by taking Equation (16) into Equation 14as follows:…”

“…In order to improve the energy regenerative performance under the requirement for meeting a certain damping performance, the genetic algorithm is used to optimize the parameters of the EHA, which can reduce the risk of being trapped in a locally optimal solution and make the optimization results more accurate [21,22].…”

A Novel Sliding Mode Control Framework for Electrohydrostatic Position Actuation System

“…Thus, EHSAS demonstrates many advantages, such as high efficiency, high reliability, compact structure, and stable output force. EHSAS has been applied in a variety of fields, such as more electric actuation system of aircraft or ship [1,2], active suspension of a vehicle [3,4], angle control of cannon and radar, flow rate and pressure control of injection molding machine [5][6][7], and position and force control of robot [8][9][10][11]. Moreover, the superiority of EHSAS has become prominent with the recent emergence of several new components, such as an integrated electrohydraulic pump (IEHP) and single-rod symmetrical cylinder.…”