This paper addresses new hybrid approaches for velocity control of an electro hydraulic servosystem (EHSS) in presence of flow nonlinearities and internal friction. In our new approaches, we combined classical method based-on sliding mode control and Mamdani networks. The control by using adaptive networks need plant’s Jacobean, but here this problem solved by sliding surface. It is demonstrate...

Hydraulic actuators are characterized by their ability to impart large forces at high speeds and are used in many industrial motion systems. In applications where good dynamic performance is important it is common to contain the actuator in a servo loop comprising a feedback transducer and electronic controller. The majority of electronic servo-controllers used in these systems are analogue bas...

This paper proposes a novel active disturbance compensation framework for exactly positioning control of electro-hydraulic systems (EHSs) subject to parameter deviations, unknown dynamics, and uncertain external load without velocity measurement mechanism. In order accurately estimate then actively compensate the effects these uncertainties disturbances on system combination between an extended...

Fluid pumping losses are one of the major sources of torque loss in modern Continuously Variable Transmissions (CVTs) due to the high pressures and flow rates required in the hydraulic control system. To reduce the magnitude of these losses, researchers at UC Davis have developed a servo-pump control system for CVTs designed for improved pressure and ratio controllability with minimal power con...

Uncertainties in the values of the parameters of a system can originate from the manufacturing tolerances of the system components, which can produce a degree of unreliability in the performance of the system. A systematic framework for realistic reliability assessment of an electro-hydraulic servo system has been presented in this paper with the objective of providing adequate information for ...

Nowadays, the active suspension is the key technology for vehicles to achieve both ride comfort and control performance. In this paper, a new 1/4T servo-hydraulic vehicle active suspension system is developed and two control schemes are utilized. The first one is a conventional PID controller obtained from Ziegler-Nichols method and the second one is the neural network controller. Though these ...

This paper presents a unified and systematic assessment of ten position control strategies for a hydraulic servo system with single-ended cylinder driven by a proportional directional control valve. We aim at identifying those methods that achieve better tracking, have a low sensitivity to system uncertainties, and offer a good balance between development effort and end results. A formal approa...

This paper presents two nonlinear model-based control designs for a hydraulic system that consists of two mechanically coupled hydraulic cylinders actuated each by a separate servo-valve. Based on a physically-oriented nonlinear mathematical model of the test rig, a further model simplification results in a completely controllable MIMO system. Two different control structures are discussed and ...

A hydraulic lifting-moving-rail equipment test bench is designed, which can lift and move the rail for examining and repairing. The loading system is an electric-hydraulic servo control system. The original control strategy has some disadvantages, such as overshoot and slow response, which severely effect dynamic performance and test precision of system. According to the fuzzy control theory, t...