Development Of Detection System Of The NOx Sensor Ceramic Chip

With the rapid development of the automotive industry and people’s increasingemphasis on environmental protection, countries have formulated and implemented moreand more stringent vehicle exhaust emissions standards. These put forward higherrequirements for the NOx sensor which plays a vital role in the entire automobile exhaustafter treatment system. In order to promote the development of the NOx sensor andguarantee the quality of it, it is necessary to develop more reliable test system. At present,these are very little research reports on the NOx sensor test system in domestic article.This article designed and developed a detection system of the NOx sensor ceramicchip which used to detect the resistance heating capability and the sensitivity of electrodematerial potential. The system can match different ceramic chip, achieve a adjustableheating temperature, and rapidly and reliably determine the degree of sensitivity of theelectrode material. The system is divided into three parts: the mechanical structure part,the hardware part and the software part. This paper does some research and design worksaround above-mentioned parts as follows:At first this paper analyzes the work principles of NOx sensor and heating controlstrategy. And the hardware feedback was selected as the test method for this project.Then the technical solutions and total scheme of the detection system were put forward.Secondly,details the three major components of the system: the mechanical structure partis arm to provide quickly air and nitrogen atmosphere conditions for chip; the hardwarepart is the core part of the system, mainly by the power circuit, the main control circuit,communication circuit, heating control circuit, the solenoid valve drive control circuit,the electrode signal acquisition circuit; the software part take charge of communicatingwith the host computer, receiving instruction and completing the appropriate action of thenormal operation of the main protection MCU and peripheral functions. Thirdly, testexperiments for the application of the system and ESC, ETC test were completed and theexperimental data is analyzed. Finally, at the end of the paper, the entire system issummarized.