New Design And Implementation Of A Low Cost Engine Control System

Because of rapid development of autos market in China and the severe competing situation in the latest years, OEMs have to put the challenge of lowing down the cost to the first place, as while as committing to improving products' quality to meet customers' requirement.Engine control module (ECM) is the most central part in vehicle electronical control modules. The quality of ECM directly affects the key performances of a vehicle. For example, power capability, safety performance, driving performance and gas consumption, etc. Therefore, it is the precondition that we have to reduce the cost on materials and manufacturing without debasingthe performance. That is to say, we should use a smarter way to fulfill the quondam function as well as to realizethe purpose of reducing cost.In this article, we take emphases on two ways for lowing down the cost on ECM. One is to cancel the Stand-by Power chip and another is to delete the acceleration sensor. But there are some data that must be kept in the Non Volatile RAM which needs the stand-by power chip as its power supply. In order to fulfill the memorization of the system parameters, we have to find another memory area to simulate the Non-volatile RAM, so that it can ensure that the data would be saved even if the ECM is power off. According to this issue, we put forth the way of memorizing ECM parameters in FlashROM. After the reallocation of core cpu memory, we made a new FlashROM operate module to do the rewriting job. Together with a new After-Run and power-on verification mechanism, we finally realize the memorization of system function parameters in FlashROM.An acceleration sensor used to be the key point for rough road detection and EBOD. However, we also cancele the acceleration sensor because of the consideration of hardware cost. In this dissertation, it raises a solution to detect the rough road, which is based on the attribution of engine roughness. Through analying statistical distribution of engine roughness when vehicle drives on rough road or misfire happens, rough road can be detected correctly and the misdetection caused by misfire can also be avoided. After software simulation and vehicle tests, it is proved that rough road detection via statistics method has similar effectiveness as acceleration sensor.