| 1. |
- Aguilar, Luis T., et al.
(författare)
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Generating oscillations in inertia wheel pendulum via two-relay controller
- 2012
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Ingår i: International Journal of Robust and Nonlinear Control. - Malden : Wiley-Blackwell. - 1049-8923 .- 1099-1239. ; 22:3, s. 318-330
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Tidskriftsartikel (refereegranskat)abstract
- The problem of generating oscillations of the inertia wheel pendulum is considered. We combine exact feedback linearization with two-relay controller, tuned using frequency-domain tools, such as computing the locus of a perturbed relay system. Explicit expressions for the parameters of the controller in terms of the desired frequency and amplitude are derived. Sufficient conditions for orbital asymptotic stability of the closed-loop system are obtained with the help of the Poincare map. Performance is validated via experiments. The approach can be easily applied for a minimum phase system, provided the behavior of the states of the zero dynamics is of no concern. Copyright (C) 2011 John Wiley & Sons, Ltd.
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| 2. |
- Vazquez, Carlos, et al.
(författare)
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Second Order Sliding Mode Control of a Mobile Hydraulic Crane
- 2014
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Ingår i: 2014 IEEE 53RD ANNUAL CONFERENCE ON DECISION AND CONTROL (CDC). - 9781467360906 ; , s. 5530-5535
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Konferensbidrag (refereegranskat)abstract
- A second order sliding mode control design for a mobile hydraulic system, including bounded model uncertainties and external disturbances, is the subject of study. The proposed algorithm provides a continuous control signal, achieving good performance and chattering attenuation in comparison to other sliding-mode-based techniques. The design includes the formulation of a partial stability problem and we provide the required Lyapunov-function-based analysis. Experimental results are performed over an industrial setup and confirm the effectiveness of the methodology. Moreover, promising results of a comparison with the Super-Twisting and PID controllers are presented.
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| 3. |
- Aguilar, Luis T., et al.
(författare)
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Performance Analysis of Relay Feedback Position Regulators for Manipulators with Coulomb Friction
- 2013
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Ingår i: Proc. 12th European Control Conference. - NEW YORK, NY 10017 USA : IEEE. - 9783033039629 ; , s. 3754-3759
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Konferensbidrag (refereegranskat)abstract
- The purpose of the paper is to analyze the performance of several global position regulators for robot manipulators with Coulomb friction. All the controllers include a proportional-differential part and a switched part whereas the difference between the controllers is in the way of compensation of the gravitational forces. Stability analysis is also revisited within the nonsmooth Lyapunov function framework for the controllers with and without gravity pre-compensation. Performance issues of the proposed controllers are evaluated in an experimental study of a five degrees-of-freedom robot manipulator. In the experiments, we choose two criteria for performance analysis. In the first set of experiments, we set the same gains to all the controllers. In the second set of experiments, the gains of the controller were chosen such that the work done by the manipulator is similar.
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| 4. |
- Andersson, Alina, et al.
(författare)
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Analytic Parameterization of Stabilizing Controllers for the Surge Subsystem of the Moore-Greitzer Compressor Model
- 2013
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Ingår i: Proc. 2013 American Control Conference (ACC2013). - 0743-1619. - 9781479901777 ; , s. 5257-5262
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Konferensbidrag (refereegranskat)abstract
- This paper is based on a new procedure for dynamic output feedback design for systems with nonlinearities satisfying quadratic constraints. The new procedure is motivated by the challenges of output feedback control design for the 3-state Moore-Greitzer compressor model. First, we use conditions for stability of a transformed system and the associated matching conditions to find the data of the stabilizing controllers for the surge subsystem. Second, using the set of stabilizing controllers satisfying the given constraints for the closed-loop system with the dynamic output feedback controller we made optimization over the parameter set. We present the data of the stabilizing controllers and the new constraints for the corresponding parameters. The contributions in this paper are simplified conditions for the synthesis and optimization over the control parameter set.
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| 5. |
- Andersson, Alina, et al.
(författare)
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Robustness of the Moore-Greitzer Compressor Model's Surge Subsystem with New Dynamic Output Feedback Controllers
- 2014. - 3
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Ingår i: 19th IFAC World Congress. - : Elsevier. - 2405-8963. - 9783902823625 ; 47, s. 3690-3695
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Konferensbidrag (refereegranskat)abstract
- This work presents an extension of a design procedure for dynamic output feedback design for systems with nonlinearities satisfying quadratic constraints. In this work we used an axial gas compressor model described by the 3-state Moore-Greitzer compressor model (MG) that has some challenges for output feedback control design (Planovsky and Nikolaev 1990), (Rubanova 2013). The more general constraints for the investigation of the robustness with respect to parametric uncertainties and measurement noise are shown.
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| 6. |
- Aranovskiy, Stanislav, et al.
(författare)
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Adaptive compensation of disturbances formed as sums of sinusoidal signals with application to an active vibration control benchmark
- 2013
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Ingår i: European Journal of Control. - : Elsevier BV. - 0947-3580 .- 1435-5671. ; 19:4, s. 253-265
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Tidskriftsartikel (refereegranskat)abstract
- An intuitive solution for the problem of adaptive attenuation of a disturbance formed as a finite sum of unknown sinusoidal signals is proposed for an internally stable discrete-time plant. The compensator is formed as a weighted sum of stable filters. An identification-based procedure for adaptive tuning of the coefficients is proposed for the case of unknown disturbance. We also propose a time-invariant compensator that provides perfect attenuation of a disturbance for the case when a model identification error is sufficiently small and disturbance frequencies are known. The technique is applied to a case study on a challenging benchmark example in the field of active vibration control. Attenuation of a disturbance formed as a sum of up to three sinusoidal signals with unknown/time-varying frequencies is demonstrated via simulation and experimental studies. (C) 2013 European Control Association. Published by Elsevier Ltd. All rights reserved.
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| 7. |
- Aranovskiy, Stanislav, et al.
(författare)
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МОДЕЛИРОВАНИЕ И ИДЕНТИФИКАЦИЯДИНАМИКИ ЗОЛОТНИКОВОГО ГИДРОРАСПРЕДЕЛИТЕЛЯ : ЧАСТЬ I. МОДЕЛИРОВАНИЕ / ЧАСТЬ II. ИДЕНТИФИКАЦИЯ
- 2013
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Ingår i: Scientific and Technical Journal «Priborostroenie». - 0021-3454. ; 56:4, s. 253-265
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Tidskriftsartikel (refereegranskat)abstract
- ЧАСТЬ I. МОДЕЛИРОВАНИЕ:Проанализированы подходы к моделированию гидрораспределителя. Предложена модель динамики золотника в гидрораспределителе, состоящая из двухподсистем — линейной и статически нелинейной.ЧАСТЬ II. ИДЕНТИФИКАЦИЯ:Предложен метод идентификации параметров модели, использующий датчикидавления и не требующий измерения положения штока золотника. Приведенырезультаты экспериментов.
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| 8. |
- Fodor, Szabolcs, et al.
(författare)
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Static friction modeling and identification for standard mechatronic systems
- 2014
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Ingår i: Proceedings of the 14th Mechatronics Forum International Conference Mechatronics 2014. - Karlstad : Karlstads universitet. - 9789170635649 ; , s. 30-36
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Konferensbidrag (refereegranskat)abstract
- In this paper we study two approaches of static friction identification in a pendulum system using specific controlled motions. We use two models: the well-known Tustin model and a polynomial model. Both models are identified using the least squares approximation method. For the identification generated point-to-point trajectories are designed in such a way that the closed-loop system guaranties constant velocity and torque regimes needed for capturing the friction points. Simple nominal controllers (PI, PD, PID) are used in the closed-loop during the friction measurement process. A model based compensation method is implemented for tracking improvement. The identification and compensation methods used in this paper can be implemented in a straightforward way for precision improvement of industrial mechatronic systems.
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| 9. |
- Freidovich, Leonid B., Docent, 1973-, et al.
(författare)
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Analysis of limit-cycle walking for a compass-like biped robot
- 2010
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Ingår i: 8th IFAC Symposium on Nonlinear Control Systems. - : Elsevier. - 9783902661807 ; , s. 1181-1186
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Konferensbidrag (refereegranskat)abstract
- We consider an impulsive mechanical system modeling dynamics of a planar two-link walker commonly known as a compass-gait biped. It is assumed that there is actuation in the hip but that the desired periodic trajectory describes an unstable passive walking gait. We recall and apply a recently developed technique for design of orbitally stabilizing feedback controllers. After that, we illustrate how to assess various properties of the closed-loop system. In particular, sensitivity to perturbations of the slope of the walking surface is analyzed and an estimate for possible deviations from the nominal trajectory is computed analytically.
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| 10. |
- Freidovich, Leonid B., Docent, 1973-, et al.
(författare)
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On generating pre-defined periodic motions in underactuated mechanical systems : The cart-pendulum example
- 2011
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Ingår i: 18th IFAC World Congress. - : Elsevier. - 9783902661937 ; , s. 4588-4593
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Konferensbidrag (refereegranskat)abstract
- We study the problem of generating oscillations in underactuated mechanical systems with a chosen time-evolution of some of the generalized coordinates. We consider a classical planar pendulum on a cart example and find conditions of existence of a solution. These conditions are expressed in terms of functions defining synchronization between the actuated and underactuated variables known as virtual holonomic constraints. Explicit expressions for these functions are computed for the cart-pendulum system where the pendulum angle is set to follow a trajectory like a pure sinusoidal waveform around the upright equilibrium. Once the valid virtual constraint has been found with the proposed method, the earlier developed techniques can be applied in order to design an orbitally stabilizing feedback control law. © 2011 IFAC.
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