Research And Application Of Vehicle Online Diagnosis Based On CAN Bus

In order to meet the consumers' requirements for safety,comfort,and entertain-ment of their cars,manufacturers have to pay more attention to improving the auto-motive electronics technology.Among these technologies,the CAN bus-based vehicle diagnosis is very popular.Through the car's CAN bus we can carry out wide range of vehicle diagnosis,not only can understand the vehicular failure and status,but also to obtain the information of auto parts.In view of the current vehicular diagnosis methods,this paper researches on the vehicle diagnosis through concrete protocol implementation and experimental analy-sis.And introduces the contents,methods and differences of the OBD-based and UDS-based vehicle diagnosis based on some related examples.The main contributions of this paper are as follows:1.Describe the design and implementation of vehicle diagnosis system based on OBD protocol.In order to design the vehicle diagnostic system based on OBD protocol,this paper introduces the concept of OBD protocol and describes the com-munication mechanism of it.Verifies the system's feasibility through the devices,cloud system and specific experiments.2.Introduce communication mechanism of UDS protocol,realize the rain flow counting method and load counting in vehicular engine diagnosis.This paper mainly explains how to collect the data of the engine through the relevant UDS protocol and carry out the Rainflow Counting Method on the collected data.Describes the relationship between multiple engine parameters(such as stress data,fuel injection data,engine speed,etc.)through load calculation.Finally,diagnoses and analyzes the engine by use of these two counting methods.3.Based on the existing software and hardware environment,establish the experimental environment of vehicle diagnosis.This paper verifies the feasi-bility of CAN bus communication by experiments and actual tests.Realizes OBD and UDS data collection and calculation on the diagnostic devices.The cloud sys-tem receives,stores and processes the data which is uploaed from device.At last,accomplishes the function of online diagnosis.The experimental results show that the CAN bus-based vehicle diagnosis method proposed in this paper can obtain the status and faultes of the vehicle through some calculations and processing,and can also diagnose the use of automobile engine.