This paper studies the energy-saving adaptive robust precision motion control of a single-rod hydraulic cylinder through the use of programmable valves. The programmable valves used in this study is a unique combination of five proportional cartridge valves connected in such a way that the meter-in and meter-out flows can be independently controlled by four of the valves as well as a true cross...

This paper studies the high performance robust mo tion control of electro-hydraulic servo-systems. The dynamics of hydraulic systems are highly nonlinear and the system may be subjected to non-smooth and discontinuous nonlinearities due to directional change of valve opening, friction, and valve overlap. Aside from the nonlinear nature of hydraulic dynamics, hydraulic servo systems also have la...

• Non-linear dynamics modelling description for simulating the behaviour of forestry cranes 2014 • Modeling an industrial flotation process: A case study at the mining company Boliden AB 2012 • Modeling dynamics of an electro-hydraulic servo actuated manipulator: A case study of a forestry forwarder crane 2012 • Underactuated mechanical systems: Contributions to trajectory planning, analysis, a...

The concept of a hydraulic axis plays a central role within the design and analysis of hydraulic systems. A hydraulic axis comprises working, control, and supply elements that realize a subfunction of a hydraulic system. Analyzing a system’s functional structure means to identify the hydraulic axes along with their couplings. The paper in hand addresses this problem; it presents concepts and al...

Preliminary note The aim of the investigation was to compare and unveil efficiency of electro-hydraulic control (EHR) system to mechanical three point hitch regulation in mouldboard ploughing. Increase of working velocity and three point hitch automatic regulation activity decreased depth of ploughing at both regulation systems but electro-hydraulic system done it more accurately since deviatio...

In the nuclear power sector, electricity is generated from the steam generated by large turbines which are highly reliant on efficient electro-hydraulic turbine speed control systems (EHC). These systems offer a wide range of control options and operate at pressures of over 1000 psi to ensure rapid hydraulic response. At these pressures the potential for leaks of hydraulic fluid is greater as i...

Hydraulic actuator has been widely used in industrial applications due to its fast response and capability of moving heavy load. The nonlinear properties of hydraulic cylinder had challenged researchers to design a suitable controller for position control, motion control and tracking control. Based on these problems, we had done a real-time digital tracking control studies on electrohydraulic c...

In the general framework of hydraulic servo systems, this paper addresses the problem of position control in the presence of important friction nonlinearities. The accent falls on the variable structure methodology, as we try to use its intrinsic robustness properties. Several friction observers, including the one based on a variable structure approach, were incorporated and tested in an accele...

The intriguing history of disturbance cancellation control is reviewed in this thesis first, which demonstrates that this unique control concept is both reasonable and practical. One novel form of disturbance cancellation, ADRC (Active Disturbance Rejection Control), attracts much attention because of its good disturbance rejection ability and simplicity in implementation. Hydraulic systems ten...