This paper studies the high performance robust motion control of electro-hydraulic servo-systems driven by double-rod hydraulic actuators. The dynamics of hydraulic systems are highly non-linear and the system may be subjected to nonsmooth and discontinuous non-linearities due to directional change of valve opening, friction and valve overlap. Aside from the non-linear nature of hydraulic dynam...

Uncertainty, Sensitivity and Geostatistical Studies of Flow and Contaminant Transport in Heterogeneous Unsaturated Zone by Feng Pan Dr. Zhongbo Yu, Examination Committee Chair Associate Professor of Hydrology University of Nevada Las Vegas Dr. Jianting Zhu, Examination Committee Co-Chair Associate Professor of Hydrologic Science Desert Research Institute The objectives of this study are: (1) to...

In this paper the control problem of a hydraulic servo-system is addressed. The performance achievable by classical linear controllers, e.g. PD, are usually limited due to highly nonlinear behavior of the hydraulic dynamics. This paper adopts the backstepping design strategy to develop a Lyapunov-based nonlinear controller for a hydraulic servo-system. Load, hydraulic and valve dynamics are inc...

In this study a modified entropy-based measure is presented for evaluating the serviceability level of water distribution networks in which the hydraulic uncertainties (flow rates in pipes) as well as the uncertainties due to mechanical parameters (failure probabilities of links) are considered simultaneously. In the proposed entropy calculation method, the connectivity order of the network dem...

This paper presents a new weighted entropy-based measure for assessing reliability of water distribution networks. The proposed methodology considers both of mechanical uncertainties (probability of pipe failure) and uncertainties due to hydraulic parameters (flow in pipe) simultaneously. In this methodology a penalty function is defined for different links of the network based on their probabi...

This paper studies the coordinated motion control of robotic manipulators driven by single-rod hydraulic actuators. Compared to conventional robot manipulators driven by electrical motors, hydraulic robot arms have a richer nonlinear dynamics and stronger couplings among various joints (or hydraulic cylinders). This paper presents a physical model based adaptive robust control (ARC) strategy to...

This paper studies the coordinated motion control of robotic manipulators driven by single-rod hydraulic actuators. Compared to conventional robot manipulators driven by electrical motors, hydraulic robot arms have a richer nonlinear dynamics and stronger couplings among various joints (or hydraulic cylinders). This paper presents a physical model based adaptive robust control (ARC) strategy to...

This paper uses a multiscale statistical framework to estimate groundwater travel times and to derive conditional travel time probability densities. In the applications of interest here travel time uncertainties depend primarily on uncertainties in hydraulic conductivity. These uncertainties can be reduced if the travel times are conditioned on scattered measurements of hydraulic conductivity a...

This article presents the identification and control of an electro-hydraulic crane. The crane is of the type used on forestry vehicles known as forwarders, which travel off-road collecting logs cut by the harvesters. The dynamics identified include significant frictional forces, dead zones, and structural and hydraulic vibrations. The control algorithm proposed, comprised of a linear controller...

This paper studies the coordinated motion control of a hydraulic arm driven by single-rod hydraulic actuators (a scaled down version of an industrial backhoe/excavator arm). Compared to conventional robot manipulators driven by electrical motors, hydraulic arms have a richer nonlinear dynamics and strong couplings among various joints (or hydraulic cylinders). This paper presents a physical mod...