Hydraulic Servo-systems

Jelali, Mohieddine; Kroll, Andreas

doi:10.1007/978-1-4471-0099-7

Cited by 263 publications

(53 citation statements)

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“…Due to the fact that the input of the valve is an electric current but the interface card output is in the form of an electric voltage it is in common to use a current to voltage converter. The constant of this converter is considered in the servo valve gain coefficient [11,12]. For an ideal critical centre, servo valve with a matched and symmetric orifice the input/output flow rate from the servo valve through the orifices (assuming negligible leakage) can be expressed in the following form:…”

Section: System Description and Dynamical Modellingmentioning

confidence: 99%

Design of Lyapunov based nonlinear velocity control of electrohydraulic velocity servo systems

2017

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Original scientific paper Development of a hydraulically driven process of steel centrifugal die casting industry requires accurate response of position in time. In the frame of preliminary investigations the analysis and control of electrohydraulic velocity servo system is considered in the presence of flow nonlinearities and internal friction. The nonlinear and uncertainty characteristics make the conventional controller not yield to the system high requirements. Two different nonlinear design procedures are employed: feedback linearization and backstepping. It is shown that both these techniques can be successfully used to stabilize any chosen operating point of the system. Additionally, invaluable new insights are gained about the dynamics of the system under consideration. This illustrates that the true potential of constructive nonlinear design lies far beyond the mere task of achieving a desired control objective. All derived results are validated by computer simulation of the nonlinear mathematical model of the system. Keywords: computer simulation; electro-hydraulic velocity servo system; integrator backstepping; Lyapunov methods; velocity control Dizajniranje nelinearne regulacije brzine elektrohidrauličkog servo sustava metodom LyapunovaIzvorni znanstveni članak Razvoj regulacijskog sustava hidrauličkog pogona u procesu centrifugalnog lijevanja čelika zahtijeva točan pozicijski i vremenski odaziv sustava, kako bi se što preciznije izlio lijev. U okviru preliminarnih istraživanja razmatrana je dinamička analiza i regulacija elektrohidrauličkog brzinskog servosustava, kod koje nastupaju nelinearnosti prouzrokovane hidrauličkim tokom i unutrašnjim trenjem. Nelinearnosti i nesigurnosti u dinamičkim karakteristikama otežavaju postizanje visokih zahtjeva po stabilizaciji upotrebom konvencionalnih regulatora. Prikazana su dva različita primjera nelinearnog konstruiranja regulatora, prvi kod kojeg je postignuta linearizacija povratnim ciklusom, i drugi primjer linearizacije povratnim korakom. Uporabom oba regulatora postignuta je učinkovita stabilizacija u bilo kojoj radnoj točki sustava. Isto tako ostvaren je i bolji uvid u dinamičke karakteristike sustava što daje dodatnu vrijednost spomenutom regulatoru. Rezultati su potvrđeni računarskom simulacijom uporabom nelinearnog matematičkog modela sustava.

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Section: System Description and Dynamical Modellingmentioning

confidence: 99%

Design of Lyapunov based nonlinear velocity control of electrohydraulic velocity servo systems

2017

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“…Therefore it is useful to use manufacturer's catalogue information which provides the well-known step responses and frequency responses for various sizes and types of valves. The inspection of step responses and frequency diagrams suggests an approximation of the SV by a second order model of the form [17].…”

Section: Description Of the Sv Dynamicsmentioning

confidence: 99%

“…The commonly used empirical equation for calculation of the effective bulk modulus for hydraulic cylinders is expressed as [17]:…”

Section: Hydraulic Actuator Dynamicsmentioning

confidence: 99%

Design of Lyapunov Based Nonlinear Position Control of Electrohydraulic Servo Systems

Detiček

Kastrevc

2016

SV-JME

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Electrohydraulic servo systems take important place in modern industrial automation. It has been used in many kinds of mechanizations, including robots, computer numerical control (CNC) press brakes, computer controlled testing machines, etc.Electro hydraulic actuator system has become one of the most important actuators in the recent decades. It offers many advantages such as good capability in positioning, fast and smooth response characteristics and high power density. Due to its capability in positioning it has given a significant impact in modern equipment for position control applications [1] and [2]. The applications in position control can be found in production assembly lines, robotics, aircrafts and testing equipment [3] and [4]. However, excellent positioning in these applications requires an accurate electro hydraulic actuator. Therefore, the development of suitable controller which could reflect such characteristics is very significant, although the dynamics of electro hydraulic servo system is highly nonlinear [5] and [6].In ordinary feedback systems the method of feedback linearization is used to eliminate nonlinearities. Feedback linearization employs changes of coordinates to transform a given nonlinear system into equivalent linear one. A major advantage of feedback linearization approach is related to the cancelations of systems nonlinear dynamics that are introduced in design process. On the other hand some kinds of nonlinearities can have positive effects on system stability, therefore their cancellation can lead to instability in the presence of modelling uncertainties. As a solution to this problem the integrator backstepping approached is proposed. The fundamental concept of backstepping method is introduced by Krstic et.al. in their book [7].The approach focusing on the stabilization problem in stochastic nonlinear systems is developed in the extension of this book.

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“…1) is discussed in port-Hamiltonian framework. This section discusses an empirical model www.intechopen.com in Merrit (1967) and Jelali & Kroll (2002), which is equivalent to the model in Fig. 2.…”

Section: Proof Of Theoremmentioning

confidence: 99%

“…See Jelali & Kroll (2002) for this modeling assumptions in detail. As the port-Hamiltonian systems are generalization of classical Hamiltonian system (the energy conservation law), the following system is given as a generalization of the continuous law (19)…”

Section: Generalized Continuous Lawmentioning

confidence: 99%

Passivity Based Control of Hydraulic Linear Arms Using Natural Casimir Functions

Sakai¹

2010

Cutting Edge Robotics 2010

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Hydraulic Servo-systems

Cited by 263 publications

References 0 publications

Design of Lyapunov based nonlinear velocity control of electrohydraulic velocity servo systems

Design of Lyapunov based nonlinear velocity control of electrohydraulic velocity servo systems

Design of Lyapunov Based Nonlinear Position Control of Electrohydraulic Servo Systems

Passivity Based Control of Hydraulic Linear Arms Using Natural Casimir Functions

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