Observer-Based Output Feedback Control Of Electronic Throttle

With the development of automotive electronics and increasingly stringent emissions regulations, the traditional engine throttle, which is the engine intake air control mech-anism, has been unable to meet the control and emission requirements, and electronic throttle came into being. To improve the electronic throttle control precision, universi-ties and automotive suppliers do widespread and profound studies on electronic throttle control.Firstly, the research summary of control problems, methods and the current status for electronic throttle is given. Then this section derived a mathematical model of the electronic throttle basing on the structure of bodies. In order to verify the reliability of the model, we carry out model checking comparing with the physical response. For not all state variables of the electronic throttle system can be measured, then an observer-based output feedback control scheme is presented for electronic throttles system. The control system consists of a reduced-order observer to estimate the unmeasurable state and a nonlinear state feedback controller. An integral action of the tracking error is introduced to reducing the steady-state error of the system. Robustness of the tracking error system is discussed in the framework of Input-to-State Stability (ISS) theory, where the model uncertainties and estimation error from the observer are considered as additive disturbance inputs, then a guideline for selecting the controller parameters is given.Finally, the designed controller is tested on hardware in the loop (HiL) experiment platform to demonstrate the effectiveness of the proposed control scheme. Simulation results show that the controller for electronic throttle has good control effect satisfying electronic throttle control requirements. The specific work is as follows:(1) The modeling process of the electronic throttle is described in this section. Here the duty cycle of voltage and the angle of the electronic throttle is considered respectively as input and output of the model. The circuit equations and kinematic equations are derived basing Kirchhoff's law and torque balance equation. Model parameters are ob-tained by model identification, and finally we carry out model checking comparing with the physical response.(2) Aiming at the nonlinear properties of electronic throttle system, the nonlinear control law is designed. In order to observe the states which can not be measured, a re-duced order observer is designed using the output variables from throttle system. Finally, an observer-based output feedback controller is designed for electronic throttle system. An integral action of the tracking error is introduced to reducing the steady-state error of the system. Robustness of the tracking error system is discussed in the framework of Input-to-State Stability (ISS) theory. Then a guideline for selecting the controller param-eters is given. Off-line simulation results show that the controller for electronic throttle satisfys electronic throttle control requirements.(3)On the basis of good off-line simulation results, the rapid prototyping experiment based on xPC-Target and semi-physical simulation experiment based on xPC-Targe and dSPACE are carried out. Rapid prototyping experiment is carried out to verify the control effect that observer-based output feedback controller acted on the physical body. And semi-physical simulation experiment is carried out to make the electronic throttle couple with the engine model from En-Dyna. Then the engine model from En-Dyna and the designed controller are respectively downloaded in xPC-Target and dSPACE. Finally, we can get the influence that the change of throttle opening makes on the entire engine system, then the effect of the electronic throttle controller is verified.