Robustness and fault-tolerance are desirable properties for hydraulic working machines and field robots. In applications where service personnel do not have easy access to the machine, it is important that the machine can continue its operation despite single machinery faults. Digital hydraulics enables a design which is inherently fault-tolerant by having each hydraulic actuator controlled by ...

Trees face the dilemma that achieving high plant productivity is accompanied by a risk of drought-induced hydraulic failure due to a trade-off in the trees' vascular system between hydraulic efficiency and safety. By investigating the xylem anatomy of branches and coarse roots, and measuring branch axial hydraulic conductivity and vulnerability to cavitation in 4-year-old field-grown aspen plan...

General models of plant vascular architecture, based on scaling of pipe diameters to remove the length dependence of hydraulic resistance within the xylem, have attracted strong interest. However, these models have neglected to consider the leaf, an important hydraulic component; they assume all leaves to have similar hydraulic properties, including similar pipe diameters in the petiole. We exa...

Developing correlations between various soil parameters are considered the major challenge to diminish time and cost associated with field measurements. Soil hydraulic and physical properties were extensively characterized using tension disc infiltrometer and soil sampling in a silty clay agricultural field in Kalaat El-Andalous, Tunisia. Tension disc infiltrometer experiments were conducted at...

Automatic hydraulic press is one of the key Ceramic machinery and equipments for pressing ceramic wall and floor tiles, and its frame withstands all of the work force when it works, so the work performances of the frame have an important impact on the structural performance of the entire automatic hydraulic press. Took the frame of 32.8MN automatic hydraulic press as research object, establishe...

abstract to estimate spatial variability of soil hydraulic functions, scaling methods were developed and have been widely used. among these functions, physically based methods have been found more desirable because of possibility of estimating soil hydraulic functions from soil physical properties. in this paper, a new and physically based method has been described for scaling soil hydraulic co...

Soil hydraulic properties are needed in globaland regionalscale circulation models for hydrologic and climate forecasting. They are also necessary in pointand nonpoint-source contaminant transport models. Prediction accuracy of these models is highly dependent on the quality of the model parameters. Collecting the required soil hydraulic parameters by direct measurement at any model grid scale ...

The hydraulic properties, such as hydraulic conductivity and water retention, of aged diesel-contaminated and bioremediated soils were examined and implications of the hydraulic properties for assessing bioremediation performance of soils were proposed. Bioremediation of diesel-contaminated soil was performed over 80 d using three treatments; (I) no nutrient added, column-packed soil, (II) nutr...

Detailed knowledge of actuator properties is a prerequisite for advanced manipulator design and control. This paper deals with the experimental identification and modelling of the nonlinear dynamics of a high performance hydraulic actuator. Such actuators are of interest for applications which require both high power and high bandwidth. An analytical model of the system is formulated, and a sof...