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...

[1] Prediction of water flow and transport processes in soils susceptible to structural alteration such as compaction of tilled agricultural lands or newly constructed landfills rely on accurate description of changes in soil unsaturated hydraulic conductivity. Recent studies have documented the critical impact of aggregate contact characteristics on water flow rates and pathways in unsaturated...

Based on an examination of K data from four different sites, a new stochastic fractal model, fractional Laplace motion, is proposed. This model is based on the assumption of spatially stationary ln(K) increments governed by the Laplace PDF, with the increments named fractional Laplace noise. Similar behavior has been reported for other increment processes (often called fluctuations) in the fiel...

permeability is a property of porous medium that quantifies rock capacity to transmit fluids. frequently, core based permeability data are not available either because of the borehole conditions or due to the high cost of coring. for these reasons, over the years attempts have been made to estimate permeability by alternative ways. permeability is an elusive parameter in hydrocarbon reservoirs ...

one of the important aspects of soil is, knowing the relationships between spatial features of soil and quantity in statistical model. the goal of this research is to estimate saturated hydraulic conductivity by regression and co-active neuro-fuzzy inference system (anfis) with using the parameters of bulk density, real density, porosity, fractal dimension of particle size, and clay percent, si...

The equations of fluids in porous media are very useful in designing the rockfill and diversion dams, gabions, breakwaters and ground water reserves. Researches have been showed that the Forchheimer equation is not sufficient for the analysis of hydraulic behavior of free-surface radial flows; because, in these flows, in addition to the hydraulic gradient and velocity, the variable of radius is...

ABSTRACT: Deceleration or stopping the vehicle without any diving and lateral acceleration is essential to develop an effective braking system. The hydraulic braking system with intelligent braking called Antilock Braking system (ABS) and Electronic Stability Control (ESC) has been introduced.  However, due to the insufficient human effort, the ABS and ESC to some extent, not function well...

The drops are used to control the descents,  stabilize the bed level, and control the upstream water level in sloping channels with less slope than the ground slope. The current study presents a numerical analysis of hydraulic characteristics in the vertical drop using computational fluid dynamics. At first, the laboratory models were used for verification and choosing the best model of turbule...

Computing optimal motions for any robot requires a good model, and a method to compute the optimal motions using that model. As research is conducted into automating operations in construction, excavation etc. there arises a need to compute optimal motions for the hydraulic machines used in these areas. Hydraulic machines disallow a simple extension of work done previously on optimal motion pla...

This paper reports on the development of a comprehensive nonlinear mathematical model of a novel inherently compliant fluidic actuator with Rotary Elastic Chambers (REC–actuator). The actuator is intended for robotic devices working in direct physical contact with humans and can be operated by both, liquid as well as gaseous working fluid. In the hydraulic realization the REC-actuator is contro...