Research On Control Strategies For Improving The Transient Performance Of Engine Speed Tracking

In order to improve the transient performance of gasoline engine and obtain the ideal power and drivability,speed control is a fundamental problem in the field of automatic vehicle control.Many domestic and foreign scholars have been devoted to this area,but the speed control of engine in transient condition is still a challenging problem based on the existing research accomplishment.The challenges mainly come from the time-varying and uncertainties of the system parameters.Considering the influences on the engine speed from the system parameter disturbances,the control strategies for improving the transient performance of engine speed tracking are studied in this paper.Among them,the main contents are shown as follows:Considering the system parameters are varying slowly with the change of the engine speed when the engine is operating on a certain condition,a double closed-loop adaptive control strategy is proposed.The strategy adapts double loop structure,each of which consists of three parts: feedforward compensation,feedback compensation and proportional-integral(PI)controller.These parts work together to overcome the influence of system parameter uncertainties and ensure the performance of engine speed tracking.Furthermore,consider the time-varying uncertainty of the parameters when engine is operating at a wide range of speed variation.In order to fully improve the transient performance of the engine,the double loop cascade active disturbance rejection control(ADRC)strategy is presented.The scheme includes an extended state observer which can be used to estimate the uncertainties in real time and a state feedback control law which is composed of PI controller and disturbance compensation controller.These parts work together to improve the transient performance of the engine speed tracking and ensure the response of steady state.In order to verify the effectiveness of the above proposed controllers,in this paper,the simulation experiments are verified on the V6 engine simulation model which developed by the Society of Instrument and Control Engineers of Japan and the Toyota research department.In order to simulate the acceleration and deceleration of the engine and the condition of speed tracking,many kinds of simulation conditions are adapted,and the simulation results under each condition are analyzed.The control effects of the adaptive and ADRC are compared and analyzed on the same conditions.In addition to this,the adaptive and ADRC are compared with double loop PI controller under the same conditions,respectively.And the transient and steady state performances of engine speed tracking under different controllers are analyzed.