The Matching Optimization Of Public Bus Powertrain

Along with the storage of the earth's oil are ceaselessly decreasing. And in order to reach the requirement of environment protection, the emission regulation becomes more and more strict. Economizing energy and protecting environment are the most important characteristics of new city public bus. No other than using the method of the matching optimization of automobile powertrain, the public bus can achieved the best operation performance.This paper constitutes the method of matching optimization public bus powertrain, the method has definite advancing and practicality.This paper established the simulated model of public bus with the commercial software of AVL-Cruise. The important module of the engine and the vehicle was tested. The test included engine economic and dynamical performance, accessories and vehicle performance. The unknown parameters of the moment of inertia and the efficiency of transmission were researched and analyzed. The results of test and simulation were carefully compared, the conclusion of analysis indicated the simulated model has high precision.This paper expounded the importance of driving cycle to the matching optimization of public bus powertrain and analyzed the driving cycle that is applicable to the public bus of China. The real public bus routes were tested with the method of velocity chart, then input real velocity chart instead of driving cycle to AVL-Cruise, finally the simulation results evaluated the performance of fuel consumption of public bus.This paper also established the evaluating system of public bus synthesized performance based on the vehicle performance of economy, dynamics and exhaust pollutants. This evaluating system synthetically and adequately took into account the influence of all kinds of factors of performance and leaned to consider according to the purpose of vehicle.Based on the right simulated model of vehicle, this public bus was simulated calculated by 270 combinatorial projects. (5 diesel engines, 9 transmissions, 6 final ratios). According to evaluation of synthesized performance evaluating system, the best matching project DK250₁2-2 compared with the original project DK2609-5, this public bus synthesized performance improved 12%.