Non-conventional processing of noisy signal in the adaptive control of hydraulic differential servo cylinders

Tar, J.K.; Rudas, Imre J.; Szeghegyi, Ágnes; Kozłowski, Krzysztof

doi:10.1109/isp.2003.1275845

Cited by 3 publications

(4 citation statements)

References 12 publications

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“…These models can correspond either to the usual universal approximators or may be taken from simple Lie groups (e.g. the Rotational Group, Lorentz Group, Symplectic Group [65], [66], [67], [68]) that are also able to provide us with uniform model structures having very limited number of independent parameters. These Lie groups do not belong to the phenomenology of the controlled systems: they are used only because they offer very convenient and lucid, geometrically interpreted possibilities for dealing with subspaces for which no actual information is available for the controller.…”

Section: General Characteristics Of Cognitive Control -What To Domentioning

confidence: 99%

Cognitive Control initiative

Tar

Rudas

Kosi

et al. 2012

2012 IEEE 3rd International Conference on Cognitive Infocommunications (CogInfoCom)

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In this paper, we make an initial effort to define the scope and goals of "Cognitive Control (CoCo)", which intends to be a research initiative for bringing about a novel generation of control systems which -in a certain sensereflect the behavior of humans while solving everyday tasks. Very briefly stated, through the use of a rich inventory of available modeling techniques, control theory has achieved profound results in model-based control approaches. However, these solutions do not seem to begin to approach the true level of human intelligence. We are convinced that by the synthesis of these "tools" from a particular point of view the great efficiency of human intelligence can be integrated/fused with the complementary virtues of our machines (e.g. high computing power, fast operation, etc.), and our CoCo initiative can be realized and applied in practice.

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Section: General Characteristics Of Cognitive Control -What To Domentioning

confidence: 99%

Cognitive Control initiative

Tar

Rudas

Kosi

et al. 2012

2012 IEEE 3rd International Conference on Cognitive Infocommunications (CogInfoCom)

View full text Add to dashboard Cite

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“…The phenomenology on the basis of which the controls in [8,9] were formed sounds as follows. Supposing the need for a desired piston acceleration computed on the basis of purely kinematic considerations, on the basis of the available system model (either omitting or involving terms regarding the piston friction), and omitting the unknown disturbance force, a desired value can be prescribed to (PA-PB/Vp).…”

Section: Formulation Of the Control Taskmentioning

confidence: 99%

“…Therefore the possibility for convergence still exists if, on the basis of (11), the desired/realized values are prescribed/observed for d-qldr?, when in the role of the physical agent controlling the motion dQldt stands instead of Q. With appropriate initial conditions, in the field of Classical Mechanics in general (11), and in the particular case of the piston now considered, (9), just correspond to this situation. In the present paper this observation is utilized.…”

Section: Formulation Of the Control Taskmentioning

confidence: 99%

“…The above approach was applied in the adaptive control of servo valve driven differential hydraulic cylinder in [8], and has been improved in [9]. Both approaches were common in the use of the phenomenology of the hydraulic cylinder in a very cautious manner that avoided prescribing a PID control due to the general angst regarding the non-linearities generated by friction.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Fractional order adaptive control for systems of locally nonlinearizable nonlinearities

Tar

Bencsik

Koztowski

2005

Proceedings of the Fifth International Workshop on Robot Motion and Control, 2005. RoMoCo '05.

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In this paper electromagnetic servo valve controlled differential hydraulic cylinders are considered as paradigms of non-linear systems that have locally nonlinearizable nonlinearities. One of them is of hydrodynamic origin: theflow resistance of the system is proportional to the square root of certain pressure difference that has infinite derivative at zero. The other nonlinearity is caused by the discontinuous behavior of the friction and adhesion forces between the piston and the cylinder at zero piston velocity. Such a behavior is dificult to control by the traditional PID controllers.Furthermore, uncertainties and variation of the hydrodynamic parameters in general make it unrealistic to develop an accurate model for such systems. Brocker and Lemmen proposed two different control approaches for the differential hydraulic cylinders based on the disturbance rejection, and on the partial flatness principles, respectively. In each case it was necessary to measure the external disturbance force and its timederivative as well as to know the exact model of the system. Later on Tar et al. proposed an alternative adaptive approach that does not require to measure the disturbance force and to know the exact parameters of the cylinder. This method rejected to use time-derivatives because of the presence of friction, and, as a consequence it resulted in a very hectic transient phase of learning. In this paper an alternative approach is presented that combines this approach with the use of calculated time-derivatives that are "rejected" by adaptively varying the order of the derivation applied. In this way the harsh initial transients can be evaded. The operation of the method is presented by simulations.

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Fractional order adaptive control for hydraulic differential cylinders

Tar¹,

Bencsik²

IEEE 3rd International Conference on Computational Cybernetics, 2005. ICCC 2005.

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Hydraulic servo valve controlled differential cylinders are non-linear, strongly coupled multivariable electromechanical tools applicable for driving e.g. manipulators. Traditional PID control of such equipment have to cope with the problem of instabilities due to the friction forces between the piston and the cylinder, and the uncertainties and variation of its hydrodynamic parameters that in general makes it unrealistic to develop an accurate model for them. Briicker and Lemmen proposed two different control approaches for such systems, based on the disturbance rejection, and on the partial flatness principles, respectively. In each case it is necessary to measure the external disturbance force and its timederivative as well as to know the exact model of the hydraulic cylinder. Later on Tar et al. proposed an alternative adaptive approach that does not require to measure the disturbance force and to know the exact parameters of the cylinder. This method rejected to use time-derivatives because of the presence of friction, and, as a consequence it resulted in a very hectic transient phase of learning. In this paper an alternative approach is presented that combines this approach with the use of calculated time-derivatives that are 'rejectedn by adaptively varying the order of the derivations applied. In this way the harsh initial transients can be evaded. The operation of the method is presented by simulations.

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Non-conventional processing of noisy signal in the adaptive control of hydraulic differential servo cylinders

Cited by 3 publications

References 12 publications

Cognitive Control initiative

Cognitive Control initiative

Fractional order adaptive control for systems of locally nonlinearizable nonlinearities

Fractional order adaptive control for hydraulic differential cylinders

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