We report on our experience with fixed-order H∞ controller design using the HIFOO toolbox. We applied HIFOO to various benchmark fixed (or reduced) order H∞ controller design problems in the literature, comparing the results with those published for other methods. The results show that HIFOO can be used as an effective alternative to existing methods for fixed-order H∞ controller design.

A anti-slug control requires operation around an open-loop unstable operating point. One solution is to design a robust controller based on a mechanistic model. An alternative and more robust approach is to identify an unstable model of the system based on input-output data. We used a closed-loop step test to identify an unstable linear model. From this, we obtained a second order IMC (Internal...

Recent success in nonlinear H∞ control design has been applied to control of robot manipulator systems. In this paper a Global H∞ robust controller is considered for tracking control problem of Robotic manipulators. The synthesis of this controller is based on Lyapunov function instead of solving the HJI equation. Performance issues of the Global H∞ robust controller are illustrated in a simula...

The robust controller designed by conventional H∞ optimal control is complicated, high-order, and difficult to implement practically. In industrial applications, structures such as lead-lag compensators and PID are widely used because their structure is simple, tuning parameters are fewer, and they are lower-order. Their disadvantages are that control parameters are difficult to tune for good p...

Manipulation of deformable objects is a field of research that has a variety of applications, including medical procedures, food industry, and manufacturing. This paper compares the performance of a standard PID controller and a robust H∞ controller, both of which are designed to perform the task of indirect deformable object manipulation. The H∞ controller is generated using methods outlined b...

This paper is concerned with the problem of H∞ controller design for networked control systems (NCSs) with time delay, packet dropout and time-varying sampling period. The considered NCSs may receive more than one control input during a sampling period. A multi-objective optimization methodology in terms of linear matrix inequalities (LMIs) and the discrete Jensen inequality are adopted to deal...

paper proposes a new design procedure of a fixed-structure robust controller for the joint space control of a pneumatic robot arm. The proposed technique is based on the concept of H ∞ loop shaping which is a sensible method for robust controller design. However, in conventional H ∞ loop shaping, the order of the controller is much higher than that of the plant. It is not easy to implement this...

This paper introduces an analysis of the phenomena of stability of synchronous machines under small perturbations by examining the case of a single machine connected to a large system through external impedance, and uses robust control H∞ techniques to design stabilizer for electric power system. H techniques that are used are H -optimal controller synthesis, H mixed sensitivity controller synt...

This paper proposes a novel robust control scheme based on delay-dependent H∞for unified power quality conditioner (UPQC) in a microgrid under the influence of the delay and parameter uncertainties. A new UPQC model considering the effects of the delay and parameter uncertainties is established. Then, the H∞ controller is designed based on the cone complementarity linearization (CCL) algorithm....

This paper is concerned with the mixed H2/H∞ control problem. The purpose of this paper is to give an iterative algorithm for finding a sub-optimal static state feedback controller for the mixed H2/H∞ control problem. The key idea of our algorithm is to construct two “controller sets”: one is a set of controllers that improve the H2 norm of the closed loop map for a given controller and the oth...