Look-ahead gear-shifting strategy on ramps for heavy trucks with automated mechanical transmission

Xiao-Yan Cong,Zeng-Cai Wang,Hong-Xuan Zhu,Chun-Peng Wang,Yong-Gang Zhang

doi:10.1177/1687814018822911

Abstract

Look-ahead information has been applied to vehicle shift systems and has led to the development of innovative changes in shifting strategies. A shifting strategy significantly influences the dynamic and economic performance of a truck. If a shift control system can predict the information of the road ahead, then the dynamic programming method can be used to obtain an optimal shift schedule, thereby achieving the best balance between the dynamic and the economic performance of a truck. Determining the weights of the economic and dynamic performance of a truck is critical in dynamic programming. Weight is related to road slope value; hence, this study uses different weights on 3%, 5%, and 10% ramp simulation experiments to investigate the relationship between fuel consumption and running time and to determine the optimum weight for different slopes. On the basis of the optimal shift schedule obtained via dynamic programming, the ramp information of the road ahead can be utilized to adjust the shift point to avoid unnecessary shifting before entering the slope and reduce shift times on a ramp. An actual truck test shows that the anthropomorphic shifting strategy proposed in this study meets driver expectations and is conducive to the ramp driving of trucks with automated manual transmission.

Highlights

In the product cycle of a heavy truck, 30% of the cost is spent on fuel.[1]
We studied how to design a curve gear-shifting strategy using the look-ahead curve information in 2016.18 In section ‘‘Look-ahead gear-shifting strategy on ramps’’ of this work, a gear-shifting strategy on ramps based on the look-ahead information is studied, and an actual vehicle experiment verifies the effectiveness of anthropomorphic ramp-shifting strategy in section ‘‘Online test of the look-head gear-shifting strategy.’’ the article is concluded in section ‘‘Conclusion.’’
The application of look-ahead information to ramp-shifting strategy for trucks with automated mechanical transmission (AMT) is studied in two aspects: fuel saving and anthropomorphization

Summary

Introduction

In the product cycle of a heavy truck, 30% of the cost is spent on fuel.[1]. The main purpose of a heavy truck is to transport goods; truck manufacturers pay more attention to fuel economy than to passenger riding comfort. The definite weight coefficient in real vehicle driving will be set according to the road slope that the truck is about to enter and the optimal shift schedule can be obtained via real-time programming with DP. Fuel saving caused by the gear shift schedule, which focuses on economic weight, is significantly reduced with an increase in slope value.

Results

Conclusion