Study And Develop On Networked Electric Control System For AMT In Heavy-Duty Vehicle

Automated Mechanical Transmission (AMT) is formed to implement automatic shift through combining the traditional fixed shaft transmission and dry-type clutch with electric control unit (ECU), sensors and the corresponding actuator. AMT had been a very important trend since the middle of 70s last century because its transmission efficiency is higher, its cost is lower and its manufacture is easy.The performance of AMT is improved, perfected and enhanced with the application of electric technology and modern control technology. Especially in the middle of 90s last century, the equipped network on the vehicle was permeated to improve the control performance of AMT system and reduce the amount of sensor and wiring harness, which paved the way for the trade of AMT.The research is the important part of the science and technology tackle key project of chongqing—"The development of automatic mechanic transmission system and product for heavy-duty vehicle"and is an item—"The development of automatic mechanic transmission for heavy-duty commercial vehicle"which is sponsored by the"863"plan. According to the requirement of heavy-duty vehicle to modern AMT electric control system, based on the SAE J1939 protocol,the electric control system is regarded as a intelligence node of CAN communication network on board and designed by adopting digital signal processing chip (DSP)—TMS320LF2407A.This research is aiming at constructing and implementing the networked AMT electric control system. The electric injection engine (EDC7UC31) and the transmission of FAST are my research objects. The control strategies of clutch-engaging and select-shifting are established and the control programs for the corresponding blocks are developed.(1)The development trend of intelligence and networked control for AMT is presented based on the analyses for the progress and trend of AMT. The relation between engine, clutch and transmission in the AMT system is pointed out and the cooperation of each control subsystem is necessary. The constituents of the modern AMT system and the basic essential factors of constructing the networked AMT electric control system are analyzed.(2)The characteristics of CAN network and the contents of J1939 protocol and the PGN definition for electric control unit of EDC7UC31 engine are analyzed.Based on SAE J1939 protocol, the intelligent pitch point PDU code of the networked AMT are formulated, which lay the network control foundation for realizing networked AMT control system.(3)The control for clutch and transmission in AMT are studied, which provided some foundation for control system design and realization. The optimal dynamical shift rule of heavy-duty vehicle is constituted and the implement process of appling fuzzy logic to control clutch in the DSP system is discussed.(4)The main control board, sampling drive board and monitor block hardware system of intelligent AMT control node are developed based on DSP TMS320LF240A processor of TI corporation. At the same time, electromagnetism compatibility of vehicle controller and anti-jamming design for DSP system is discussed.(5)The signals sampling and processing block, SAE J1939 communication program, serial communication program, clutch control and select-shift control block are designed on the foundation of the above hardware system, which establish a solid foundation for the system integration and system test in the future.