Design of noninteracting control systems using root locus methods

A new method is developed for the synthesis of linear multivariable control systems for noninteraction. One of the principle differences of this synthesis method as compared to previous methods presented in the literature is that root locus techniques are employed. The root locus approach considerable simplifies the synthesis problem and also allows the designer the freedom of making a compromise between the selection of compensators based upon economical factors and the selection of closed-loop system performance. Forward loop compensation in the synthesis method. For a system with n inputs and n outputs, n² compensators will generally be required. The synthesis method is carried out by considering only a single channel at a time. By arranging the compensators in a particular topological form, conventional root locus techniques may be employed wherein a single gain parameter varies the roots of the characteristic equation for a given single channel. The individual gain parameter for a particular channel can be varied to achieve a variety of closed-loop performances for that channel without influencing the performances of other channels in the system. Any necessary change in the basic locus structure can be affected by changing only n controllers that govern the performance of a single channel. In the actual application of the synthesis method methodical details are not required to be remembered. The practicing engineer may employ this synthesis, from time to time, without extensive review of techniques by following six basic steps that are outlined in the thesis. The six steps of the synthesis method are illustrated in several numerical design problems. The results of an analog computer simulation study for questionable cases of stability which involve right half plane poles and zeroes are presented. The results of this simulation are gratifying