Amir Nassirharand and S.R. Mousavi Firdeh
The purpose of this paper is to describe the application of a systematic single‐range controller design procedure to control a cruise missile.
Abstract
Purpose
The purpose of this paper is to describe the application of a systematic single‐range controller design procedure to control a cruise missile.
Design/methodology/approach
The controller design approach is based on one describing function model of the missile followed by linear system identification. The missile includes discontinuous nonlinear terms, and therefore, a small signal model is not obtainable by straight linearization. Once a linear approximation to the quasilinear model of the missile is obtained, a H∞ controller is designed to achieve a robust nonlinear closed‐loop system.
Findings
It is found that performance of the closed‐loop system with the applied simple controller design approach competes with one other complicated describing function‐based controller design technique.
Research limitations/implications
At present, the research is limited to design of linear H∞ controllers.
Practical implications
The major outcome of this paper is the verification that the applied simple describing function‐based H∞ controller design procedure may be used to design high‐performance controllers for cruise missiles.
Originality/value
This is the first paper that adopts an existing single‐range H∞ controller design procedure to design high‐performance controllers for cruise missiles.
Details
Keywords
The paper's purpose is to initiate an effort that will result in a systematic approach for design of control systems for multivariable, nonlinear, and unstable space robots.
Abstract
Purpose
The paper's purpose is to initiate an effort that will result in a systematic approach for design of control systems for multivariable, nonlinear, and unstable space robots.
Design/methodology/approach
The design approach is based on multivariable describing function (DF) models of the space robot coupled with the use of factorization technique. The design approach is to obtain the multivariable DF models followed by application of a previously developed factorization‐based controller design formula. Finally, the design must be verified by a non‐linear simulation to make sure that approximations made during design are valid.
Findings
It is found that the DF approach may successfully be applied in order to control nonlinear, multivariable, and unstable systems such as space robots.
Research limitations/implications
At present, the approach is verified to be applicable to rigid space robots.
Practical implications
The major outcome of this research is that complicated controllers of a class of space robots may be replaced by simpler controllers, taking into account the amplitude dependency features of the space robot; this amplitude dependency is the most important characteristic of a non‐linear system.
Originality/value
This is the first paper in the area of multivariable and unstable space robot controller design that is based on the application of the DF technique. In fact this is the first work in the area of general unstable non‐linear control system design that is based on a DF technique.