Hydraulic fracturing has been used widely to stimulate production of oil, natural gas, and geothermal energy in formations with low natural permeability. Numerical optimization of fracture stimulation often requires a large number of evaluations of objective functions and constraints from forward hydraulic fracturing models, which are computationally expensive and even prohibitive in some situa...

| This paper addresses the control problem of hydraulic robot manipulators. The backstepping design methodology is adopted to develop a novel nonlinear position tracking controller. The tracking errors are shown to be exponentially stable under the proposed control law. The controller is further augmentedwith adaptation laws to compensate for parametric uncertainties in the system dynamics. Acc...

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-...

This paper studies the precision motion control of single-rod hydraulic actuators with accurate parameter estimations. An integrated direct/indirect adaptive robust controller (DIARC) is proposed to take into account the inherent nonlinearity, parametric uncertainties and uncertain nonlinearities associated with the hydraulic systems. Compared with existing direct ARC controller designs, the pr...

This work introduces an approach for taking into account the uncertainty of pipe friction coefficients and nodal demands in the hydraulic analysis of water supply networks. For this purpose, uncertainties are represented by fuzzy numbers and incorporated into the network's governing equations. Input uncertainties are spread out on the network and influence its hydraulic responses, including pip...

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-...

In the present work, we use an adaptive robust approach for fault detection and accommodation in electro-hydraulic systems. It is well known fact that any realistic model of a hydraulic system suffers from significant extent of uncertain nonlinearities and parametric uncertainties. An adaptive robust scheme is robust to such uncertainties and tracks the change in parameters reliably. Consequent...

This paper studies the motion control of single-rod hydraulic actuators regulated by proportional directional control(PDC) valves with deadband and nonlinear flow gains. The boom motion control of a hydraulic robot arm driven by a singlerod hydraulic actuator is used as a case study. The experimental system dynamics are highly nonlinear. In addition, the system has large extent of modeling unce...