Hydraulic systems, as power source and transmission, offer many advantages over electromechanical or purely mechanical counterparts in terms of power density, flexibility and portability. Many hydraulic systems require touching and contacting the physical environments; and many of these systems are directly controlled by human. If hydraulic systems are passive, they would be safer to interact w...

A new approach to the design of light manipulator arms with long links is proposed in this paper. In contrast with traditional schemes, a flexible link is provided with a special force unloading system (FUS) having electrohydraulic drives. As a result, the static and dynamic errors caused by link structural deflections are minimized. Strategy of control the unloading actuators with measuring st...

In this paper we present an application of fault identification and control reconfiguration in the context of a high performance aircraft. A second order divided difference filter is used to identify an internal leakage fault in an electrohydraulic actuator found in the aircraft elevator. The identified fault information is then utilized in the formulation of an aircraft systems model for progn...

Consideration of the effects of the mounting structure stiffness on electrohydraulic servomechanisms actuating primary flight controls yields a switched control system of seven nonlinear differential equations. The stabilizing control synthesis has to cope with the critical case of a zero eigenvalue of the Jacobian matrices calculated in equilibria. By local coordinates transformations, the swi...

Systems discretized using the conventional z-transform and zero-order-hold will lead to sampling zeros lying outside the unit circle upon fast sampling. The Euler operator has been shown to be an alternative to discretizing systems. The resulting discrete-time form approaches its original continuous-time form as the sampling interval approaches zero. A model reference adaptive controller is des...

This paper describes the system analysis and control design of an electrohydraulic servo-drive using a nonlinear composite feedback control approach based on singular perturbation theory (Kokotovic, Khalil & O’Reilly 1986). A comparison with linear output feedback (P-control) and linear state feedback (LQRdesign) shows the bene¿ts of the proposed method. The nonlinear control design features fe...

The objective of this work is to present some results concerning the neuro-fuzzy control synthesis as applied to electrohydraulic servomechanisms actuating primary flight controls. This represents a remarkable control strategy, with antisaturating and antichattering properties, which is in fact independent of mathematical model of the system, thus achieving certain robustness and reducing compl...

Shock waves, high-energy sound or pressure waves (like thunder following lightening or a small, focused explosion), have little to do with electric shock. Shock waves can be generated in many ways, but electrohydraulic devices have the greatest capacity to produce and project high energy to a deep focal depth. ESWT can be highly focused and can achieve a focal point beyond 10 cm into deeper tis...

The paper presents some main aspects regarding multi-parametric quadratic programming (mp-QP) problems. Model Predictive Control (MPC) is considered as a particular mp-QP problem, and this powerful tool is applied for control and simulation through a case study. Since the solutions to mp-QP problems can be expressed as piecewise affine linear functions of the state, a new implementation in term...

This paper focuses on the generation of dynamic models for an electrohydraulic forestry machine. Such models can be used for training simulators, for sizing components, and for system design. The most complex model includes base compliance, and pendulum-like motions of the processing head suspended from an end-point. A NewtonEuler iterative method, implemented symbolically, is used to include b...