| 1. |
- Shiriaev, Anton, et al.
(författare)
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Virtual-Holonomic-Constraints-Based Design of Stable Oscillations of Furuta Pendulum: Theory and Experiments
- 2007
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Ingår i: IEEE Transactions on Robotics. - 1941-0468 .- 1552-3098. ; 23:4, s. 827-832
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Tidskriftsartikel (refereegranskat)abstract
- The Furuta pendulum consists of an arm rotating in the horizontal plane and a pendulum attached to its end. Rotation of the arm is controlled by a DC motor, while the pendulum is moving freely in the plane, orthogonal to the arm. Motivated, in particular, by possible applications for walking/running/balancing robots, we consider the Furuta pendulum as a system for which synchronized periodic motions of all the generalized coordinates are to be created and stabilized. The goal is to achieve, via appropriate feedback control action, orbitally exponentially stable oscillations of the pendulum of various shapes around its upright and downward positions, accompanied with oscillations of the arm. Our approach is based on the idea of stabilization of a particular virtual holonomic constraint imposed on the configuration coordinates, which has been theoretically developed recently. Here, we elaborate on the complete design procedure. The results are illustrated not only through numerical simulations but also through successful experimental tests.
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| 2. |
- 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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| 3. |
- 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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| 4. |
- Freidovich, Leonid B., 1973-, et al.
(författare)
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Shaping stable periodic motions of inertia wheel pendulum : theory and experiment
- 2009
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Ingår i: Asian Journal of Control. - : Wiley. - 1561-8625 .- 1934-6093. ; 11:5, s. 549-556
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Tidskriftsartikel (refereegranskat)abstract
- We consider an underactuated two-link robot called the inertia wheel pendulum. The system consists of a free planar rotational pendulum and a symmetric disk attached to its end, which is directly controlled by a DC-motor. The goal is to create stable oscillations of the pendulum, which is not directly actuated. We exploit a recently proposed feedback-control design strategy based on motion planning via virtual holonomic constraints. This strategy is shown to be useful for design of regulators for achieving orbitally exponentially stable oscillatory motions. The main contribution is a step-by-step procedure on how to achieve oscillations with pre-specified amplitude from a given range and an arbitrary independently chosen period. The theoretical results are verified via experiments with a real hardware setup.
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| 5. |
- Freidovich, Leonid, et al.
(författare)
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Friction Compensation Based on LuGre Model
- 2006
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Ingår i: Proc. 45th IEEE Conf. Decision & Control (CDC 2006). - New York : IEEE. ; , s. 3837-3842
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Konferensbidrag (refereegranskat)abstract
- We consider a tracking problem for mechanical systems. It is assumed that feedback controller is designed neglecting some disturbances, which could be approximately modeled by a dynamic LuGre friction model. We are interested to derive an additive observer-based compensator to annihilate or reduce the influence of such a disturbance. We exploit a recently suggested approach for observer design for LuGre friction-model-based compensation. In order to follow this technique, it is necessary to know the Lyapunov function for the unperturbed system, parameters of the dynamic friction model, and to have certain structural property satisfied. The case when this property is passivity with respect to the matching disturbance related to the given Lyapunov function is illustrated in the paper with an example of a DC-motor. The main contribution is some new insights into numerical real time implementation of friction compensators for various LuGre type models. The other contribution, built upon the main one, is experimental verification of the suggested observer design procedure.
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| 6. |
- Freidovich, Leonid, et al.
(författare)
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LuGre-Model-Based Friction Compensation
- 2010
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Ingår i: IEEE Transactions on Control Systems Technology. - 1558-0865 .- 1063-6536. ; 18:1, s. 194-200
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Tidskriftsartikel (refereegranskat)abstract
- A tracking problem for a mechanical system is considered. We start with a feedback controller that is designed without attention to disturbances, which are assumed to be adequately described by a dynamic LuGre friction model. We are interested in deriving a superimposed observer-based compensator to annihilate or reduce the influence of such a disturbance. We exploit a recently suggested approach for observer design for LuGre-friction-model-based compensation. In order to apply this technique, it is necessary to know the Lyapunov function for the unperturbed system, as well as the parameters of the dynamic friction model, and to verify that a certain structural property satisfied. The case when the system is passive with respect to the matching disturbance related to the given Lyapunov function is illustrated in this brief with a DC-motor example. The main contribution is some new insights into the numerical real-time implementation of a compensator for disturbances describable by one of various LuGre-type models. The other contribution, which is built upon the main one, is experimental verification of the suggested model-based observer design procedure.
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| 7. |
- Freidovich, Leonid, et al.
(författare)
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Periodic Motions of the Pendubot via Virtual Holonomic Constraints: Theory and Experiments
- 2008
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Ingår i: Automatica. - : Elsevier BV. - 0005-1098 .- 1873-2836. ; 44:3, s. 785-791
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents a new control strategy for an underactuated two-link robot, called the Pendubot. The goal is to create stable oscillations of the outer link of the Pendubot, which is not directly actuated. We exploit a recently proposed feedback control design strategy, based on motion planning via virtual holonomic constraints. This strategy is shown to be useful for design of regulators for achieving: stable oscillatory motions, a closed-loop-design-based swing-up, and propeller motions. The theoretical results are verified via successful experimental implementation.
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| 8. |
- Freidovich, Leonid, et al.
(författare)
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Stable Periodic Motions of Inertia Wheel Pendulum via Virtual Holonomic Constraints
- 2007
-
Konferensbidrag (refereegranskat)abstract
- We present a new control strategy for an underactuated two-link robot, called inertia wheel pendulum. The system consists of a free planar rotational pendulum and a symmetric disk, attached to its end and directly controlled by a DC-motor. The goal is to create stable oscillations of the pendulum, which is not directly actuated. We exploit a recently proposed feedback control design strategy, based on motion planning via virtual holonomic constraints. This strategy is shown to be useful for design of regulators for achieving orbitally exponentially stable oscillatory motions. The main contribution is a step-by-step recipe on how to achieve oscillations with pre-specified amplitude from a given range and an arbitrary independently chosen period.
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| 9. |
- Freidovich, Leonid, et al.
(författare)
-
Stable Periodic Motions of the Pendubot via Virtual Holonomic Constraints
- 2006
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Ingår i: Proc. 3rd IFAC Workshop on Lagrangian and Hamiltonian Methods for Nonlinear Control.
-
Konferensbidrag (refereegranskat)abstract
- This paper presents a new control strategy for an underactuated two-link robot, called the Pendubot. The goal is to create stable oscillations of the outer link of the pendubot, which is not directly actuated. We exploit a recently proposed feedback control design strategy, based on motion planning via virtual holonomic constraints. This strategy is shown to be useful for design of regulators for achieving: stable oscillatory motions, a closed-loop-design-based swing-up, and propeller motions.
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| 10. |
- Johansson, Rolf, et al.
(författare)
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Observer-based Strict Positive Real (SPR) Switching Output Feedback Control
- 2004
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Ingår i: 2004 43rd IEEE Conference on Decision and Control (CDC). - 0191-2216. - 0780386825 ; 3, s. 2811-2816
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Konferensbidrag (refereegranskat)abstract
- This paper considers switching output feedback control of linear systems and variablestructure systems. Theory for stability analysis and design for a class of observer-based feedback control systems is presented. It is shown how a circlecriterion approach can be used to design an observerbased state feedback control which yields a closedloop system with speci ed robustness characteristics. The approach is relevant for variable structure system design with preservation of stability when switching feedback control or sliding mode control is introduced in the feedback loop. It is shown that there exists a Lyapunov function valid over the total operating range and this Lyapunov function has also interpretation as a storage function of passivity-based control and a value function of an optimal control problem. The Lyapunov function can be found by solving a Lyapunov equation. Important applications are to be found in hybrid systems with switching control and variable structure systems with high robustness requirements.
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