Partner: A. Myśliński

Systems Research Institute, Polish Academy of Sciences (PL)

Recent publications
1.Pisarski D., Myśliński A., Online adaptive algorithm for optimal control of structures subjected to travelling loads, OPTIMAL CONTROL APPLICATIONS & METHODS, ISSN: 0143-2087, DOI: 10.1002/oca.2321, Vol.38, No.6, pp.1168-1186, 2017
Abstract:

The problem of adaptive optimal semiactive control of a structure subjected to a moving load is studied. The control is realised by a change of damping of the structure’s supports. The results presented in the previous works of the authors demonstrate that switched optimal controls can be very efficient at reducing the vibration levels of the structure. On the other hand, these controls exhibit a high sensitivity to changes of the speed of the travelling load. The aim of this paper is to develop an algorithm that enables real-time adaptation of the optimal controls according to both the measured speed of the travelling load and the estimated state of the structure. The control objective is to provide smooth passage for the vehicles and reduce the material stresses on the carrying structures. The designed adaptive algorithm uses reference optimal controls computed for constant speeds and a set of functions describing the sensitivity of the system dynamics to the measured parameters. The convergence of the algorithm, as well as aspects of its implementation, is studied. The performance of the proposed method is validated by means of numerical simulations conducted for different travelling speed scenarios. In the assumed objective functional, the proposed adaptive controller can outperform the reference optimal solutions by over 50%. The practicality of the proposed method should attract the attention of practising engineers.

Keywords:

Adaptive control, Moving load, Online optimal control, Sensitivity analysis, Structural vibration control

Affiliations:
Pisarski D.-IPPT PAN
Myśliński A.-Systems Research Institute, Polish Academy of Sciences (PL)

List of chapters in recent monographs
1.
299
Bajer C.I., Myśliński A., Żochowski A., Dyniewicz B., Interactive computer environment for solving optimal problems-IDOS, rozdział: Optimal control problems described by PDEs., Springer, pp.101-123, 2012
2.
300
Bajer C.I., Myśliński A., Żochowski A., Dyniewicz B., Pisarski D., Interactive computer environment for solving optimal problems-IDOS, rozdział: Solving optimal control problems described by PDEs, Ed. R. Pytlak, pp.347-394, 2012

Conference papers
1.Pisarski D., Myśliński A., Online adaptive semi-active vibration damping of slender structures subject to moving loads, ICoEV 2017, International Conference on Engineering Vibration, 2017-09-04/09-07, Sofia (BG), DOI: 10.1051/matecconf/201814805006 , No.148, pp.1-6, 2018
Abstract:

The paper deals with the adaptive optimal semi-active control of the slender vibrating structures subjected to the moving loads. The deflection of the structure is governed by Euler-Bernoulli beam equation approximated by the system of bilinear ordinary differential equations. The damping function of the structure support is chosen as the control function. The optimal control problem consists in finding such bang-bang control function to minimize the energy as well as the vibrations of the carrying structure. Although the switched optimal control is a very efficient tool in the reduction of structure vibrations it is very sensitive with respect to changes of the speed of the traveling load. This paper deals with the development of the adaptive descent type algorithm that enables the update of the optimal controls in real time based on the measured speed of the traveling load or structure’s state. The proposed algorithm uses reference optimal controls computed for the constant speeds and the set of functions describing the sensitivity of the system dynamics with respect to the measured parameters. Numerical computations are carried out for different speed scenarios of the moving load. The obtained numerical results indicate that the proposed adaptive controller can significantly outperform the reference optimal solutions.

Affiliations:
Pisarski D.-IPPT PAN
Myśliński A.-Systems Research Institute, Polish Academy of Sciences (PL)

Conference abstracts
1.Pisarski D., Myśliński A., Online adaptive semi-active vibration damping of slender structures subject to moving loads, ICOEV2017, International Conference on Engineering Vibration, 2017-09-04/09-07, Sofia (BG), pp.1, 2017
Abstract:

In this paper, the problem of the optimal control of a structure subjected to a moving load has been studied. In contrast to the previous works of the authors, focused on open-loop strategies, this paper has been devoted to an adaptive closed-loop control, where the switched damping strategy is subject to real-time adaptation according to the measured speed of the moving load.
The proposed adaptive controller has been designed based on the use of the reference optimal solutions computed for a given constant velocity and a set of functions describing the sensitivity of the system dynamics to a change in the speed and the initial state. All these data are pre-computed offline and stored in the controller's memory. As a result, the online computational algorithm, based on a simple gradient descent loop, uses a minimal calculation effort. This allows almost immediate updating of the optimal controls, even with the use of a standard PC. The method has been validated by means of numerical experiments carried out for a wide range of the velocity perturbation scenarios. The proposed scheme is general for a class of time-varying bilinear control systems and can be implemented to a wide range of problems concerned with smart structural elements.

Affiliations:
Pisarski D.-IPPT PAN
Myśliński A.-Systems Research Institute, Polish Academy of Sciences (PL)