Automobile Engine Electronic Throttle Control System Design Studies

Auto electronic control has made rapid progress by more requirements of the society, pending tougher emission standards and the developments in electronics, and Drive-by-Wire is one of the most important technologies. ETCS (electronic throttle control system) is one part of the powertrain control system, it plays a very important role in powertrain control. This thesis firstly introduced the ETCS, then modeled and simulated its dynamics and electrics characters in Matlab/simulink/stateflow, and the model based embedded software code is generated, then test is curried out in the real-time workshop.The whole thesis consists of six sections:Chapter 1 briefly states the ETC technique developing-history, features, the current application situation and products, and then points out the significance of the thesis and the main content of the research work.Chapter 2 analyzes the dynamics of each part of the throttle body, including pneumatics, spring torque, friction (Coulomb and stick-slip friction) etc., and then deduces mathematical model of ETCS. And system identification is also done using the toolbox of Matlab.Chapter 3 begins with introductions of PID arithmetic, the theory of VSC (variable structure control) its application, principle and foreground. Then a PID controller and a VSS controller is designed for the throttle plate position control.Chapter 4 firstly introduces the model-based embedded software design method, then a control strategy research platform based on Matlab software is presented. Especially important content of real-time control software: flow chart, finite state machine, tasks, scheduler, control-flow and data-flow are discussed. Then the subsystem models of ETCS in Matlab are showed, including sensor model, motor model, plate model and controller model. Its interaction is also explained. Finally the simulate result and analysis are talked. Because of using a lot of resources and integrating analysis, simulation and real-time control, the efficiency of research is improved greatly.Chapter 5 constructs a set of test-bed, including DCM, throttle body, data acquisition card and the driving power IC. A real-time test is curried out, and the expected throttle plate position and motor current are compared to the actual values and they fit well.The final chapter draws conclusions form the research findings and the next steps are pointed out.