For the purpose of engineering development for a new 8-step speed automatic transmission,a simplified dynamic model for this gearbox was established and key parameters which affected the shift quality were analyzed.Ai...For the purpose of engineering development for a new 8-step speed automatic transmission,a simplified dynamic model for this gearbox was established and key parameters which affected the shift quality were analyzed.Aiming at four different shift types,the ideal characteristics of shift clutch and engine control were set up.By using torque estimation method,PI slip control algorithm and engine coordinated control principle,the control model and transmission controller were well developed for three shift phases which included rapid-fill phase,torque phase and inertia phase.The testing environment on the rig and prototype vehicle level was built and the testing results obtained in ultimate condition could verify the accuracy and feasibility of this shift control strategy.The peak jerk during shift process was controlled within ±2 g/s where the smooth gearshift was obtained.The development proposal and algorithm have a high value for engineering application.展开更多
Good access to traffic information provides enormous potential for automotive powertrain control.We propose a logical control approach for the gearshift strategy,aimed at improving the fuel efficiency of vehicles.The ...Good access to traffic information provides enormous potential for automotive powertrain control.We propose a logical control approach for the gearshift strategy,aimed at improving the fuel efficiency of vehicles.The driver power demand in a specific position usually exhibits stochastic features and can be statistically analyzed in accordance with historical driving data and instant traffic conditions;therefore,it offers opportunities for the design of a gearshift control scheme.Due to the discrete characteristics of a gearshift,the control design of the gearshift strategy can be formulated under a logic system framework.To this end,vehicle dynamics are discretized with several logic states,and then modeled as a logic system with the Markov process model.The fuel optimization problem is constructed as a receding-horizon optimal control problem under the logic system framework,and a dynamic programming algorithm with algebraic operations is applied to determine the optimal strategy online.Simulation results demonstrate that the proposed control design has better potential for fuel efficiency improvement than the conventional method.展开更多
基金Project(51105017) supported by the National Natural Science Foundation of ChinaProject(2011BAG09B00) supported by the National Science and Technology Support Program of ChinaProject(2010DFB80020) supported by the Technology Major Project of the Ministry of Science and Technology of China
文摘For the purpose of engineering development for a new 8-step speed automatic transmission,a simplified dynamic model for this gearbox was established and key parameters which affected the shift quality were analyzed.Aiming at four different shift types,the ideal characteristics of shift clutch and engine control were set up.By using torque estimation method,PI slip control algorithm and engine coordinated control principle,the control model and transmission controller were well developed for three shift phases which included rapid-fill phase,torque phase and inertia phase.The testing environment on the rig and prototype vehicle level was built and the testing results obtained in ultimate condition could verify the accuracy and feasibility of this shift control strategy.The peak jerk during shift process was controlled within ±2 g/s where the smooth gearshift was obtained.The development proposal and algorithm have a high value for engineering application.
基金Project supported by the National Natural Science Foundation of China(Nos.61803079,61703179,and 61890924)the Foundation of the Education Department of Jilin Province,China(No.JJKH20190189KJ)the Foundation of State Key Laboratory of Automotive Simulation and Control,China(No.20170102)。
文摘Good access to traffic information provides enormous potential for automotive powertrain control.We propose a logical control approach for the gearshift strategy,aimed at improving the fuel efficiency of vehicles.The driver power demand in a specific position usually exhibits stochastic features and can be statistically analyzed in accordance with historical driving data and instant traffic conditions;therefore,it offers opportunities for the design of a gearshift control scheme.Due to the discrete characteristics of a gearshift,the control design of the gearshift strategy can be formulated under a logic system framework.To this end,vehicle dynamics are discretized with several logic states,and then modeled as a logic system with the Markov process model.The fuel optimization problem is constructed as a receding-horizon optimal control problem under the logic system framework,and a dynamic programming algorithm with algebraic operations is applied to determine the optimal strategy online.Simulation results demonstrate that the proposed control design has better potential for fuel efficiency improvement than the conventional method.
