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To improve the comprehensive performance of vehicles equipped with stepped automatic transmission (SAT), the optimization of gearshift schedule should take into account various performance such as power performance, fuel economy, etc. In addition, the SATs would become more acceptable if the optimized gearshift schedule could also be individualized to reflect the driver’s expectation on vehicle performance to a reasonable extent. For the purpose of ensuring the comprehensive performance and improving the individual-ability (i.e., the ability to adapt to different driver’s performance expectation) of vehicles equipped with SAT, a linear weighted method has been proposed to construct a performance evaluation function, which applies different weights to represent driver’s expectation on performance by using these weights to multiply the normalized value of each sub-performance index.

To further enhance the comprehensive performance of multi-speed battery electric vehicles (MSBEVs) and meanwhile represent the driver’s expectation on performance, we need to consider the power performance, energy economy and driver’s intention together in the optimization of gearshift schedule. An optimization approach for personalized optimal gearshift schedule (POGS) for MSBEVs is put forward to tackle this issue. A quantification method for driver’s intention based on fuzzy neural network is proposed at first, which takes velocity, strength of accelerator pedal and its change rate as input, and takes driver’s expectations on performance as output. The optimization problem for POGS is then formulated with comprehensive evaluation function as goal, in which the driver’s expectations on performance are used as weights of sub-objective functions corresponding to the power performance and the energy economy, respectively.

Gearshift schedule of stepped automatic transmission (SAT) determines the timing when the gearbox should be shifted from a certain gear position to an adjacent one, which directly affects the performance of complete vehicle. To optimize the comprehensive performance considering power performance, fuel economy, and driver’s performance expectation, the formulation of gearshift schedule needs to take into account a number of factors such as the expression of different performance indices, the identification of driver’s intention on each sub-performance, and the adaption to driving conditions especially the road slope and curve. Based on our previous work, this investigation is focused on the adaptability of the gearshift schedule to curves of the road that could ensure the safety of vehicle and meanwhile maintain an optimal comprehensive performance reflecting a specific driver’s performance expectation.