In impedance control of hydraulic excavators the piston position and ram force of each hydraulic cylinder for the axis control of the boom, arm, and bucket can be determined. The problem is thus how to find the control voltage applied to the servovalves to track these commands to the hydraulic systems. This paper presents analytic, simulation and experimental results for controllers that have b...

Development of reliable power-by-wire actuation systems for both aeronautical and space applications has been sought recently to eliminate hydraulic systems from aircraft and spacecraft and thus improve safety, efficiency, reliability, and maintainability. The Electrically Powered Actuation Design (EPAD) program was a joint effort between the Air Force, Navy, and NASA to develop and fly a serie...

Soil and water resources management of rivers has an important role because of direct relation withdifferent systems such as earth, life, social and people. Although the use of vegetation cover inbioengineering and biological stabilization and also soil and water resources management projects hasmany advantages, but improper methods of design and implementation cause hydraulic specificationsof ...

Hydraulic conductivity and sorption coefficients for chlorinated hydrocarbons (chloroform, carbon tetrachloride and tetrachloroethylene) were evaluated for 216 sediment samples collected across a 15 m transect and a 21 m depth interval in a contaminated aquifer near Schoolcraft, Michigan. Relationships between hydraulic conductivity, linear sorption partition coefficients, grain size classes, a...

Suboptimal levels of phosphorus (P) strongly inhibited leaf expansion in young cotton (Gossypium hirsutum L.) plants during the daytime, but had little effect at night. The effect of P was primarily on cell expansion. Compared to plants grown on high P, plants grown on low P had lower leaf water potentials and transpiration rates, and greater diurnal fluctuations in leaf water potential. Hydrau...

This paper is concerned with real-time optimal-tuning PID control design for industrial hydraulic systems. Several optimal-tuning controller design techniques are used for a hydraulic position control system. After analysis on the system, a nonlinear dynamical model is derived. A nonlinear PID control scheme with inverse of dead zone is introduced to overcome the dead zone in this hydraulic sys...

Power system performance is affected by dynamic characteristics of hydraulic governor-turbines during and following any disturbance, such as occurrence of a fault, loss of a transmission line or a rapid change of load. Accurate modelling of hydraulic governor-turbines is essential to characterise and diagnose the system response during an emergency. In this article, both detailed and simplified...

It has been shown that sufficiently high velocities can cause the mobilisation of discolouration material in water distribution systems. However, how much typical hydraulic conditions affect the mobilisation of discolouration material has yet to be thoroughly investigated. In this paper, results are presented from real turbidity and flow observations collected from three U.K. trunk main network...

Hydraulic water distribution system (WDS) simulation models are widely used by planners, water utility personnel, consultants and many others involved in analysis, design, operation or maintenance of water distribution systems. Similarly, water quality models that work in concert with hydraulic models are now commonly used to simulate the dispersion of and changes in water quality in a water di...

The Simulation of hydraulic or electronic systems has been state of the art for a long time. For both of these domains there exist highly specialized simulation programs which can be regarded as a kind of industrial standards. Often problems arise if different domains of technology occur within one system and very detailed models are needed. As an example a universal testing machine is presente...