This article presents the design of a robust force controller for a hydraulic actuator interacting with an uncertain environment via quantitative feedback theory (QFT). After the derivation of a realistic nonlinear differential equation model, a linearized plant transfer function is developed. The effects of nonlinearities are accounted for by describing the linearized model parameters as struc...

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...

Despite the application of advanced control technique to improve the performance of electro-hydraulic position control, Proportional Integral Derivative (PID) control scheme seems able to produce satisfactory result. PID is preferable in industrial applications because it is simple and robust. The main problem in its application is to tune the parameters to its optimum values. This study will l...

The purpose of this paper is to present a robust strategy in controlling a hydraulically actuated active suspension system. The controller consists of the two controller loops namely inner loop controller for force tracking control of the hydraulic actuator and outer loop controller to reject the effects of road induced disturbances. The outer loop controller utilized a proportional integral sl...

A comparative performance analysis of the CFD platforms OpenFOAM and FLOW-3D is presented, focusing on a 3D swirling turbulent flow: a steady hydraulic jump at low Reynolds number. Turbulence is treated using RANS approach RNG k-ε. A Volume Of Fluid (VOF) method is used to track the airewater interface, consequently aeration is modeled using an EulerianeEulerian approach. Structured meshes of c...

Besides nutrient composition, the hydraulic performance of horticultural substrates is a main issue for evaluating their quality for horticultural purposes. Their water and air capacity and their suitability for transporting water are important hydraulic quality indicators. Shrinkage and water repellency could have a negative impact on storing and transporting water and solutes. The commonly us...

Hydraulic assisted power steering system is a high bandwidth servo with stringent performance requirements on accuracy, reliability, and cost. Design of such a system can be best achieved by using a validated and user friendly computer simulation program. Hydraulic integrated power steering ( HIPS ) program has been developed using basic concepts from science and engineering. HIPS provides a de...