Research On Monitoring System Of Diesel Particulate Filters Regeneration Based On CAN Bus

Diesel engine is better than gasoline engine at fuel consumption, dynamic,economy, reliability, emissions of CO, HC and CO2etc. But the particulate matter (PM)emissions of diesel engine are 30 to 80 times as many as that of gasoline engine.Currently, diesel particulate filter (DPF) is accepted as the most economic and effectivetechnology of out-engine purification for reducing diesel engine PM emissions. Thefilter body of DPF is a kind of porous ceramic materials composed of silicon carbide orcordierite. It can adsorb the diesel exhaust particulates in order to purify the exhaust,with as high as 90% filtration efficiency. However, as the adsorption quantity of solidparticulates increases, the internal space of DPF will be gradually jammed which notonly affects the efficiency of filtering, also influences the performance of the dieselengine. Therefore, some measures must be adopted to remove the deposited particulatesso as to recover the original functional performance of DPF. The process of removing iscalled DPF regeneration. There is no time to delay to develop DPF and its regenerationcontroller in order to drive the energy saving and emission reduction of diesel vehicleindustry.In order to realize the intelligent regeneration of DPF on car systems, a monitoringsystem of DPF regeneration was designed. The system includes functions ofinformation acquisition and processing, operation data record, communication, displayand regeneration control etc. It adopts high-pressure atomizing fuel injectioncombustion catalytic regeneration technology with a structure of DPF + diesel engineoxidation catalysts (DOC) + additives, which overcomes the low combustion efficiency,difficult regenerative process control and complicated structures of traditionalregeneration technologies. It also employs a distributed monitoring system based onCAN bus including vehicle monitoring module, bottom control module and onlinecomputer monitoring module. Thus, the system can easily integrate into the automotiveelectronic control system, and has higher reliability and human-computer interactionperformance. What’s more, it uses electronic technology and artificial intelligent controlstrategy to solve the determination of regeneration time and control of regenerationtemperature. Consequently, the system has high purification efficiency and durabilityregeneration, controllable performance, strong adaptation and disturbance-rejection. Hardware circuit of bottom controller and LCD operator had been designed. Thecircuit design mainly includes microprocessor, crystals and reset circuit, power circuit,data storage circuit, data acquisition circuit, control driving circuit, CANcommunication circuit, button circuit, sound and light alarm circuit, LCD display circuitetc. After finishing hardware design, the software design was carried out, including theembedded software of bottom controller and LCD operator, and the software of onlinemonitoring module. Moreover, the corresponding control strategy and communicationmechanism was formulated. On the base of hardware and software, debugging andtesting of system were finished in the lab. Finally, the road test of the whole system wasexecuted on diesel vans. The results show that the design of the whole system isreasonable and feasible, and can be put into application.