| 1. |
- Gunnarsson, Svante, et al.
(författare)
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Adaptive Compensation of Deformations in Mechanical Structures Controlled by Hydraulic Actuators
- 1990
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Ingår i: Proceedings of the 11th IFAC World Congress. ; , s. 51-55
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Konferensbidrag (refereegranskat)abstract
- In servo applications involving complex mechanical structures load forces often cause deformations in the structure. Since normally only the actuator position is measured and fed back to the control unit the deformations will introduce errors in the positioning of the load. The approach proposed in this paper is to estimate the true load position. If the stiffness between the actuator and the load is known it is possible to estimate the position of the load by measuring the actuator force/pressure. The estimation of the stiffness is based on recursive identification of the dynamics between actuator force and actuator pressure. The identified model can be used to improve the dynamic properties of the system as well as to compensate for the static error.
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| 2. |
- Gunnarsson, Svante, et al.
(författare)
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Adaptive Control of a Hydraulic Crane using On-Line Identification
- 1993
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Ingår i: Proceedings of the Third Scandinavian International Conference on Fluid Power. - Linköping : Linköping University. - 9789178710850 ; , s. 363-388
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- In this paper we present an approach to adaptive control of hydraulic actuators with flexible mechanical loads. The approach is based on recursive identification of low order models of the dynamics from valve input to actuator position and effective load pressure respectively. The model parameters are used to compute a regulator that gives a well damped system with good servo properties. The identification is carried out on-line in closed loop with no other signals than those present in normal operation. Here RLS with variable forgetting factor is used. The method does not, however, need not more paramters to be set a priori than ordinary RLS with fix forgetting factor. In this way an easily tuned and robust identification algorithm is obtained. Results from experiments carried out on a lorry crane are presented.
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| 3. |
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| 4. |
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| 5. |
- Gunnarsson, Svante, 1959-, et al.
(författare)
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LQG Control of a Hydraulic Actuator with a Flexible Mechanical Load
- 1993
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Ingår i: Proceedings of the 12th IFAC World Congress. - Linköping : Linköping University. - 9780080422121 ; , s. 469-472
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This paper presents a control system based on linear quadratic state feedback and state estimation for an hydraulic actuator with a flexible mechanical load. The purpose of the control system is to improve the dynamic properties by reducing the oscillatory behavior of the load and to eliminate the steady state error in the load position caused by external disturbances. Using a simplified linear model a control system is developed and evaluated using simulations and experiments.
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| 6. |
- Gunnarsson, Svante, et al.
(författare)
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LQG Control of an Hydraulic Actuator with a Flexible Mechanical Load
- 1991
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This paper presents a control system based on linear quadratic state feedback and state estimation for an hydraulic actuator with a flexible mechanical load. The purpose of the control system is to improve the dynamic properties by reducing the oscillatory behavior of the load and to eliminate the steady state error in the load position caused by external disturbances. Using a simplified linear model a control system is developed and evaluated using simulations and experiments.
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| 7. |
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| 8. |
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| 9. |
- Strömberg, Jan-Erik, et al.
(författare)
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Complex Hybrid Systems I : a Study of Available Tools and Specification of Planned Work
- 1994
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The aim of this report is twofold. First, to provide a common framework and terminology for the participants of the Nutek supported COHSY project a multi-disciplinary academic-industrial cooperation on COmplex Hybrid SYstems. Second, to define more precisely the activities within the nest few years of the project. Therefore, the current report should be considered as a project definition rather than a statement about the constructive work currently in progress.
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