Research on automatic gear-shift strategy of heavy truck downhill based on geographic information prediction

The presence of long slopes necessitates the installation of an auxiliary braking system in heavy trucks. However, due to the diverse range of braking methods available, drivers often encounter challenges in determining the most suitable choice and dealing with the complexity involved in their operation. Our research focuses on engine braking and exhaust braking as they relate to transmission gears. In this study, we propose an innovative automatic shift strategy that utilizes geographic information about upcoming road conditions. Through a road observation experiment, we have obtained data on the speed characteristics exhibited by heavy trucks under various downhill gradients. Based on these findings and considering both slope inclination and desired safe speeds, we select an appropriate auxiliary braking mode and plan a suitable gear position to meet the required deceleration demands while ensuring that vehicle speed remains within acceptable limits. This downhill shift strategy not only reduces operational complexity for drivers while minimizing subjective decision-making but also enhances vehicle intelligence levels and improves safety during downhill driving.