This paper presents the position tracking performance of an electro-hydraulic hydraulic servo (EHS) system using sliding mode control (SMC) with proportional-integral-derivative (PID) sliding surface. In modelling process, a mathematical model of the EHS system is developed by considering its nonlinearities as represented by a Lu-Gre friction model. The control strategy is derived from the deve...

This article describes the composition and working principle of electro-hydraulic position servo control system, and establishes a systematic mathematical model. This article presents a controller which is based on Fuzzy neural networks for an electro-hydraulic speed governor. The design process of the RBF Fuzzy neural network control is introduced in detail. This controller which combines the ...

Hydraulic systems are widely used in manufacturing processes and transportation systems where energy intensive operations are performed and “machine” control is vital. A variety of ßow control products exist including manual directional control valves, proportional directional control valves, and servo-valves. The selection of a control valve actuation strategy is dependent on the system respon...

In this paper, an adaptive piecewise linear control scheme is proposed for improving the performance and response time of servo mechanical control systems. It is a gain stabilized control technique. No large phase lead compensations or pole zero cancellations are needed for performance improvement. Large gain is used for large tracking error to get fast response. Small gain is used between larg...

This paper describes the mechanical configuration of a quadruped robot firstly. Each of the four legs consists of three rotary joints. All joints of the robot are actuated by linear hydraulic servo cylinders. Then it deduces the forward and inverse kinematic equations for four legs with D-H transformation matrices. Furthermore, it gives a composite foot trajectory composed of cubic curve and st...

The conception of raising dynamic stiffness of electro hydraulic position servo system by flow feedforward compensation is put forward. First, the elementary principle of maintaining piston position unchanged under sudden external force load change by charging additional oil volume is analyzed. Then, a scheme using double servo valves to realize flow feedforward compensation is presented, in wh...

TAbstract T— A new modeling software, AMEsim is put forward in this paper to develop a nonlinear model for a higher performance three stage electro-hydraulic servo valve. The simulation results and experimental results on existing valve are consistent, which proves that the developed model is right. The analysis of the model shows that pilot valve bandwidth mainly affects the bandwidth of three...

A car suspension incorporating a Lotus actuator and a TVR suspension/wheel unit is studied both experimentally and analytically. An emphasis is placed on hydraulic modelling using a series of transfer functions linking the hydraulic and suspension components. This is signi cantly aided by the use of a Moog 2000 programmable servo controller (PSC ) to equalize the extending and retracting ow gai...

The dynamics of hydraulic systems are highly nonlinear and the system may be subjected to non-smooth and discontinuous nonlinearities due to directional change of valve opening, friction, etc. Aside from the nonlinear nature of hydraulic dynamics, hydraulic servo systems also have large extent of model uncertainties. To address these challenging issues, a robust state-feedback controller is des...