In order to improve the performance of the hydraulic support electro-hydraulic control system test platform, a self-tuning proportion integration differentiation (PID) controller is proposed to imitate the actual pressure of the hydraulic support. To avoid the premature convergence and to improve the convergence velocity for tuning PID parameters, the PID controller is optimized with a hybrid o...

In bioreactor landfill, the leachate flow and moisture distribution depend upon saturated and unsaturated hydraulic properties of municipal solid waste (MSW). The effects of unsaturated parameters have not been studied because of scarcity of the data and variation in unsaturated parameters due to MSW heterogeneity, degree of decomposition, and pore structure. In this study, a numerical two-phas...

This paper deals with the position control of a hydraulic actuator regulated by a proportional directional control valve. The control algorithms based on the proportional-derivative controller have been applied to a specially designed two-channel electro-hydraulic servo system, which has the capacity to experimentally simulate common circumstances of a typical fluid power circuit. The first sys...

The main goal of the study is to analyze all relevant properties of the electro hydraulic systems and based on that to make a proper choice of the control strategy that may be used for the control of the servomechanism system. A combination of electronic and hydraulic systems is widely used since it combines the advantages of both. Hydraulic systems are widely spread because of their properties...

A practical approach to design a feedforward-plus-proportional-integral-derivative (FPID) controller for accurate and smooth velocity control on a hydraulic linear actuator is presented. The integrated controller consists of a feedforward loop and a PID loop. The feedforward loop is designed to compensate for the nonlinearity of the electrohydraulic system, including the deadband of the system ...

Traditional feedback linearization approach (TFL) requires a priori knowledge of plant, which is difficult and the computational efficiency of controller is low due to the complex dynamics of spatial 6-DOF hydraulic parallel manipulator. In order to improve the tracking performance of spatial 6-DOF hydraulic parallel manipulator and to conquer the drawbacks of TFL, a novel approximate feedback ...

A hybridized system is described for the continuousflow determination of serum calcium. The analysis is based on the cresolphthalein colorimetric procedure as described for use with the SMA 12/60 (Technicon Corp.). The hydraulic features of the AutoAnalyzer II are used with modules of the AutoAnalyzer 1. This combination gives both the ease of operation and hydraulic improvements inherent in th...

This paper presents the derivation, simulation, and implementation of a nonlinear tracking control law for a hydraulic servosystem. An analysis of the nonlinear system equations is used in the derivation of a Lyapunov function that provides for exponentially stable force trajectory tracking. This control law is then extended to provide position tracking. The proposed controller is simulated and...

Servo-hydraulic control is regarded as a key technology in most mechanical testing systems for the investigation of strength and fatigue properties of materials, mechanical components and structures. High performance but robust control strategies are necessary as part of the test control system to ensure high test quality and reproducible test results which are of special importance when consid...

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 ...