Optimization Research Of Economy Driving Assist Of Vehicles

The driver’s driving pattern has an important influence on vehicle’s fuel consumption. Eco-assist is used to evaluate the driving pattern bad for energy efficiency and offer prompt to improve the driver’s driving pattern, thus reducing the fuel consumption in the process.The main work of this paper is as follows:(1)Based on the bench test experimental data,the numerical model of the engine torque, the mathematical model of the engine fuel consumption and hydraulic torque converter were established.Based on the shift schedule of automatic transmission’s optimal dynamic performance and fuel economy,overall shift rules of 2-parameter were drawn up.(2)By using the DP(dynamic programming) method, eco-driving predictive optimization model was established.The engine fuel consumption is as its objective function.Considering comfort index and avoiding shift too fast,the product of the square of the acceleration and speed is as the comfortable penalty function,and the square of two stage gear difference before and after is as the shifting penalty function.In order to meet both economy and power performance requirements, reasonable calculated distance during the acceleration process was determined by analyzing the distance’s impact on the fuel consumption and driving time.(3)Applying the eco-driving predictive optimization simulation model, acceleration and road-climbing on vehicle were simulated and analyzing.Comparing to the automatic transmission shift rules of 2-parameter,the fuel consumption under the acceleration condition reduced notably by applying eco-driving strategy.Contrasting to the climbing process with constant speed,the fuel consumption under road-climbing condition also reduced notably by accelerating in advance before climbing.(4)Real-time prompt function of eco-assist was analyzed,the prompt messages incl- ude reducing accelerated speed tip,gear indication, over-speed alarm, idling alarm, and accelerating in advance when ramp appeared,and the judge condition to give the prompt was given.Part of the UDDS is chosen to simulate,and the result shows that 19.7% average saving rate within 5s was realized by driving following the economic optimization speed and gear in comparison with prediction speed(adopting overall shift rules of 2-parameter).