Research On Master-Slave ECUs Distributed Control System Of Muti-Cylinder Diesel Engine

For the advantage of low fuel consumption, low emissions, high-power, high-torque, diesel engines become more and more widely used in transportation. Electronic control system is widely used to get better engine performance, through the diesel engine’s electronic control to meet various application requirements. With the rapid development of modern technology, the traditional engine of the locomotive power unit is facing increacing challenges, such as the locomotive engine power, economy. It also has a higher demand on durability and emissions, thus the development of electronic diesel engine control system with independent intellectual rights and China’s national conditions are very important, which would improve the capacity of independent development and market competitiveness of China’s automobile, and ensure sustained, stable and healthy development of industrial diesel engines.As the larger traction power, locomotives generally used more than eight-cylinder diesel engine with electronic fuel injection system. In this paper, CAN-based distributed architecture design is used in 16-cylinder diesel engine electronic control system, detailed descriptions of engine control strategy and the software were made, and also the results of the engine bench test were analyzed. To further enhance the communication speed, this paper has studied high-speed FlexRay communications network, and the hardware and software were designed for the two net nodes. The main works of this paper are as follows:(1) Distributed architecture for multi-cylinder diesel engine has been researched, and the structural characteristics of the network board as well as diesel engine work principle were analyzed in the paper. In viewing of Multi-cylinder engine with high-speed control, CAN-based master-slave electronic control unit (ECU) system architecture was proposed. The two ECUs have the same hardware architecture, which can identify master-slave status of the ECUs by setting the I/O port line level.(2) The system software and hardware have been designed in the paper. By analyzing the hardware work principle of 16-cylinder diesel engine distributed control system, the main hardware circuits were design. The ECU has CAN communication interface, which can achieve the real-time data exchange via the CAN bus. The system software mainly includes the modules:speed acquisition, condition identification, speed control, excitation control and fault diagnosis.(3) According to the needs of the engine control process, the paper described the detail designs of control software infrastructure and application-layer for the distributed master-slave electronic control units. which includes the master-slave ECU location determination. fuel injection time synchronization. the master-ECU’s overall software process, the slave-ECU’s overall software process, engine control data and instruction communications protocol. It also has a design of the main engine control strategies, such as speed calculation, the maximum fuel limit, fuel trigger parameter calculation, emission control and fault diagnosis.(4) In order to further improve the communication speed and meet real-time exchange of large volumes of data, high-speed FlexRay network based on time-division multiplexing approach were used. The paper analyzed the characteristics of the FlexRay bus, the frame structure definition, time synchronization mechanism and the system master-slave synchronization principle. The FlexRay bus controller and drivers were added into the ECUs on the base of the original hardware, which has achieved the hardware and node design. The initialization of FlexRay was designed, and two node FlexRay communication design was implemented.Finally, to verify the design of the system, the sub-tests and bench tests were completed on the master-slave engine control system based on the CAN network and the experimental data were obtained through calibration experiments of the master-slave ECU system. The results of the experiments show that the master-slave ECU control system can stably implement the multi-cylinder diesel engine joint control and the engine has the stable speed at predetermined experimental conditions, as well as the error could be limited in 0.5%. Calibrations can be achieved by further optimization for better results.The two node FlexRay interface communication was built in the paper, and data exchange was simulated as engine. The results of the experiment show that in two slots, sender and receiver can achieve real-time data exchange and the maximum operating speed can up to lOMbit/s, which provides a solution for the follow-up replacement of the CAN.