Design method of characteristic parameters of automatic transmission based on multi-objective optimization

The performance of automatic transmission (AT) is influenced to some extent by its characteristic parameters. In the past, the design of characteristic parameters tends to take into account only the gear ratio or a very few aspects. With the increasing complexity of AT configuration, the design of the characteristic parameters should also consider more performance indicators. Therefore, this paper proposes a method for designing characteristic parameters using a multi-objective evolutionary algorithm (MOEA), which integrates five performance indicators that are affected by the characteristic parameters. Firstly, a novel 13-speed AT configuration is taken as an example, and a new optimization model of AT is proposed. The characteristic parameters of the AT are designed using a MOEA based on adaptive reference vectors. The algorithm has been tested and shown to outperform eight other algorithms in dealing with characteristic parameters design problem. Finally, the optimized characteristic parameters of 13-speed AT are obtained, and the results show that its performance can be comparable to the existing classic AT, or even better in some performances, which further demonstrates the feasibility and effectiveness of the method.