In order to study the numerical control (NC) servo press hydraulic control system and its control algorithm. The numerical control servo press performance and control principle of hydraulic control system are analyzed. According to the flow equation of the hydraulic control valve, hydraulic cylinder flow continuity equation and the force balance equation of the hydraulic cylinder with load pres...

Abstract. This work presents a cascade controller for the trajectory tracking control of a hydraulic actuator by using adaptive algorithms to deal with parametric uncertainties together with an adaptive dead-zone compensation scheme. The hydraulic actuator is modeled as a forth order nonlinear system including the valve dynamic as a first order linear system and considering a valve with a dead-...

39 S oil hydraulic parameters are essential input to most hydrologic and climatic models (Mohanty et al., 2002; Mohanty and Zhu, 2007). Th ey are used to defi ne the hydraulic characteristics of the soil vital in modeling soil moisture and fl ux in the unsaturated zone near the land–atmosphere boundary. At the scale of model applications, it is very important to defi ne the appropriate paramete...

Abstract. This work presents a cascade controller for the trajectory tracking control of a hydraulic actuator by using adaptive algorithms to deal with parametric uncertainties together with an adaptive dead-zone compensation scheme. The hydraulic actuator is modeled as a forth order nonlinear system including the valve dynamic as a first order linear system and considering a valve with a dead-...

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...

One of the most important components in hydraulic circuits is the pump that generates hydraulic power supply. The performance and the versatility of a variable displacement piston pump are, to a large extent, determined by its controller. Upgrading of existing controllers is considered one of the major means of improving the characteristics of the pump. The dynamic performance of hydraulic syst...

Numerical simulation is very useful for understanding the hydraulic fracturing mechanism. In this paper, we simulate the hydraulic fracturing using the distinct element approach, to investigate the effect of some critical parameters on hydraulic fracturing characteristics. The breakdown pressure obtained by the distinct element approach is consistent with the analytical solution. This indicates...

This paper investigates the hydrodynamic characteristics of nine stormwater pond configurations. These ponds represent an extension of earlier work by Persson (1999) who proposed the thirteen pond configurations currently used as a guide in the hydrodynamic component of the Cooperative Research Centre for Catchment Hydrology (CRCCH) Model for Urban Stormwater Improvement Conceptualisation (MUSI...