Automatic Transmission Gear Real-time Optimization And Online Decision-making Technology

There is a vital question to think about : why do we need automatic transmission gear real-time optimization and online decision-making technology? Because of the imperfect analysis of the power demand,the low accuracy of the prediction model,and the poor real-time performance of the research on intelligent shifting decision technology slow down the pace of intelligentization in the automotive industry.In this paper,set the driving maneuverability and comfort as the boundary conditions,pursue fuel consumption characteristics.Research the automatic transmission gear real-time optimization and online decision-making technology with the combination of theoretical derivation and simulation analysis,develop “customized” shift boundary conditions for different driving environments and driving intent performance conditions to achieve the optimal balance of vehicle dynamics,fuel economy and driving performance,to reduce the tedious work of shifting point calibration.The specific research content is as follows:1)Build a vehicle simulation model.A vehicle simulation model is built in AVL Cruise,and Matlab/Simulink/stateflow is mainly used to establish the shift boundary condition decision.AVL Cruise and Matlab/Simulink are jointly used to complete the reasonable switching of vehicle operating gears under the shift boundary condition.2)Extract the gear evaluation index.First,write the m file according to the analytical method to analyze the basic shift boundary conditions that focus on vehicle dynamics and fuel economics,and then further extract objective evaluation indicators that can balance vehicle dynamics,fuel economics,and driving performance.In this way,use the analytical method idea to infer the impact of different shifting boundary conditions on vehicle performance based on quantified indicators.3)Offline optimize shift boundary conditions based on dynamic programming algorithm.For vehicles operating under standard drive cycles,the gear decision-making process is decomposed into multi-stage decision-making problems.Dynamic programming theory can be used to solve the optimal solution for gear sequences that focus on fuel economics under standard drive cycles,and realize offline ‘Step by Step Precision More and More Accurate Precision' optimization.And at the same time,consider the limitations of the dynamic programming model.4)Online optimize shift boundary conditions based on model predictive control algorithm.Firstly,the vehicle longitudinal dynamics model is established.And then the state space equation is constructed and use mathematical expressions to predict the state of future state variables,implement a rolling optimization strategy to achieve the effect of real-time optimization,and "customize" online optimization of shift boundary conditions under the constraints.The research results can reduce or completely replace the complicated manual calibration work and improve the theory of automatic transmission.