Electro-hydraulic proportional control valves are widely applied for motion control in the electro-hydraulic fluid power system. Normally, a sliding spool is used in the proportional control valve to control the flow direction and flow rate passing through the valve, as a result, the meterin and meter-out orifices are mechanically connected [1]. The sliding spool makes the system robust and eas...

Variable structure control with sliding mode can provide fine control performance and robustness. However, chattering phenomenon introduced due to discontinuous switching gain limits their applications. To achieve precise tracking performance with reduced chattering effect, fuzzy sliding mode control is introduced and evolutionary simultaneous tuning of control parameters is employed. Novel evo...

In the nuclear power sector, electricity is generated from the steam generated by large turbines which are highly reliant on efficient electro-hydraulic turbine speed control systems (EHC). These systems offer a wide range of control options and operate at pressures of over 1000 psi to ensure rapid hydraulic response. At these pressures the potential for leaks of hydraulic fluid is greater as i...

In this paper one presents an electro-hydrostatic servo-actuator (EHA) driven by a brushless d.c. motor. The constructive solution studied here was chosen due to the current trends in making All-Electric Aircraft (AEA). EHA contains two subsystems: the electrical subsystem and the hydraulic subsystem. The hydraulic subsystem is composed by a local gear pump, a hydraulic cylinder with bilateral ...

In this paper, a control strategy combining the feedback linearization theory and sliding mode variable structure is proposed to solve various nonlinear factors, uncertainty of external disturbance high-precision pressure problems in Direct-Drive Volume Control (DDVC) electro-hydraulic servo system. The mathematical model DDVC system established, factors are accurately linearized by theory. com...

Abstract: Addressing the simulating issue of the helicopter-manipulating booster aerodynamic load with high-frequency dynamic load superimposed on a large static load, this paper studies the design of the robust controller for the electro-hydraulic loading system to realize the simulation of this kind of load. Firstly, the equivalent linear model of the electro-hydraulic loading system under as...

In industrial applications, the dynamic characteristics of the servo-hydraulic system are always complex and highly nonlinear. Moreover, there are too many uncertainties in it; for example, the viscosity of oil, the bulk modulus, the oil volume, the system pressure, the wear and the cavitations. The loading conditions are usually rather unsteady, and the loading forces change in a wide range du...