Research And Design Of ECU Bottom-level Driving Software For National VI Emission High Pressure Common Rail Diesel Engine

The issue of environmental protection is one of the major issues that are urgently needed to be resolved at this stage.People in modern society cannot travel without transportation.Diesel vehicles and petrol vehicles that use fossil fuels emit large amounts of pollutants,causing serious pollution to the ecological environment.In order to protect the ecological environment on which people depend,more stringent emission regulations have also been introduced.The use of highpressure common-rail electronically controlled fuel injection technology and diesel engine emission control technology combined to develop and design the diesel engine ECU bottom driver software not only ensures the power and fuel economy of the diesel engine,but also reduces the emission pollutants and protects the environment.It is of great significance to save energy and reduce emissions from diesel engines.According to the national VI emission regulations,Infineon AURIX TC275 T was selected as the ECU controller for the high pressure common rail diesel engine and the D20 TCI diesel engine as the control object.The requirements for the fuel injection system and the emission control system of the high pressure common rail diesel engine were analyzed.According to the K2 SAR software architecture,combined with the TC275 T on-chip resources,the MCU hardware and software resources are reasonably allocated and the underlying software is designed according to the functional modules: engine status acquisition module,engine speed signal processing module,fuel injection drive module,rail pressure control module,SCR drive module,VGT and EGR drive modules.Reasonable allocation of VADC channels to acquire various state parameters of the engine.Design of speed signal processing mechanism and fault-tolerant processing algorithm to effectively identify the speed signal;designed three engine phase tracking recognition algorithms to meet the different speed signal input conditions.Designed frequency multiplier Mechanism,the crankshaft and camshaft signal are respectively 100 times and 1800 times frequency multiplier,provide 0.06°CA crank angle signal for the angle base.Designed the injector solenoid valve that generates PEAK-HOLD current waveform through QSPI control power driver chip Closed-loop controller.Designed rail pressure closed-loop controller to ensure that common rail pressure is within the expected range.Designed a variable speed engine speed simulation algorithm,provided speed signal for HIL experiment.Designed SCR nozzle drive algorithm.Designed hardware Ring and gantry experiments verify the feasibility of each module code and the entire system.Through the hardware-in-the-loop experiment,the validity of the simulated speed signal was verified;the phase tracking identification algorithm was verified to work normally in the effective speed range,the injector driving algorithm can effectively control the power driving chip to generate the PEAK-HOLD waveform.The SCR nozzle current waveform meets the design requirements and the nozzle operates normally.Bench experiments showed that the diesel engine started normally and kept at idle speed with a rotation speed of 800 RPM and a pulsation range of 50 RPM to meet the design requirements.