Engine Speed Automatic Control System Theory

This paper mainly focuses on speed control of auto engine. A physics model of auto engine is established. The motion equation and its state-space model of this system are presented. Then, an entire analysis on the system is presented using MATLAB. In order to attenuate the vibration amplitude of speed as quickly as possible under external transient excitation, or keep the speed stability and minimize the vibration amplitude under external continuous force excitation, two controllers are designed. The first one is linear quadratic optimal controller, and the other one isoptimal H∞ robust controller.Firstly, design of the linear quadratic optimal controller. To begin with, the basic theory of this design method is provided. Then a linear quadratic optimal controller for the auto engine is worked out using MATLAB Control Toolbox. An entire analysis on the closed loop system with the controller is presented, including stability analysis, response analysis, parametrical uncertainty analysis, and so on.Secondly, design of optimal H∞ robust control. In the first place, the development of H∞ robust control theory is introduced. And a brief H∞ robust control theory is explained, including the concept and essence of H∞ robust control,the standard H∞ robust control problem, the design method of H∞ robust control,small gain theory, mixed sensitivity problem, weighting function selection and so on. And then, an optimal H∞ robust control for the space truss structure is designedusing MATLAB Robust Control Toolbox. Finally, an entire analysis on the closed loop system with the control is presented.Finally, parametrical uncertainty is studied to show that the controllers are robust.