We report on our experience with strong stabilization using HIFOO, a toolbox for H∞ fixed-order controller design. We applied HIFOO to 21 fixed-order stable H∞ controller design problems in the literature, comparing the results with those published for other methods. The results show that HIFOO often achieves good H∞ performance with low-order stable controllers, unlike other methods in the lit...

Robust controllers designed via H∞ Loop Shaping are complicated and are of order higher than that of the plant. It is very difficult to implement these controllers in practical engineering applications. To overcome this problem, Genetic Algorithm is used to approximate a robust PID controller from H∞ Loop Shaping controller so that the difficulties in implementation of higher order controller c...

This study investigates six degrees-of-freedom nonlinear tracking control of rigid spacecraft under external disturbances. We propose two nonlinear tracking controllers having disturbance attenuation ability, namely, a proportionalderivative (PD)-type H∞ state feedback controller and a proportional-integral-derivative (PID)-type H∞ state feedback controller. Both these controllers have positive...

The proposed article deals with uncertain description of permanent-magnet DC motor Maxon RE 35 via parametric uncertainty and H-infinity controller design. There was analyzed influence of uncertainties of the particular motor parameters on the model behavior. Consequently there was designed an H-infinity controller via Matlab functions. The behavior of the obtained controller was analyzed on th...

In this paper, the delay-dependent robust control problem is considered for time-delay systems with polytopic uncertainty. Robust stabilizing controller and robust H∞ controller are designed by using a parameter-dependent Lyapunov function that can reduce the conservativeness when used in robust performance analysis and synthesis problems for polytopic systems. Furthermore, multichannel H∞ dyna...

This paper studies order reduction issues for a vehicle active suspension system throughout its modelling, H-infinity controller design and controller refinement. Computer simulations demonstrate that an H-infinity controller for a full active suspension can be significantly reduced to nearly one third of its full order, while the active suspension performance is only slightly degraded. As a by...

This paper considers the design of an H∞ controller for tool point control of a hydraulically actuated knuckle boom crane. The paper describes the modelling of the crane’s mechanical and hydraulic systems and a disturbance model. These are linearised and combined in a state-space model used for the controller design. The controller synthesis problem is to design (if possible) an admissible cont...

This paper deals with robust performance and transient response of H∞/μ DIA control for magnetic suspension systems. H∞ DIA control is an H∞ control problem which treats a mixed Disturbance and an Initial-state uncertainty Attenuation(DIA) and supplies H∞ controls with good transients. H∞ DIA controller has a good initial response property, however its robust performance might be improved. We p...

Abstract: In this paper, we present a dynamic output-feedback receding horizon H∞ controller for linear discrete-time systems with disturbance. The controller is obtained numerically from the finite horizon output-feedback H∞ optimization problem, which is, in fact, hardly solved analytically. Under a matrix inequality condition on the terminal weighting matrix, the monotonic decreasing propert...

In this paper the optimisation of the weighting functions for an H∞ controller using genetic algorithms and structured genetic algorithms is considered. The choice of the weighting functions is one of the key steps in the design of an H∞ controller. The performance of the controller depends on these weighting functions since poorly chosen weighting functions will provide a poor controller. One ...