基于Android智能手机的汽车诊断系统的研究与实现

发布时间：2018-04-02 08:53

本文选题：OBD-II　切入点：故障诊断　出处：《中国海洋大学》2014年硕士论文

【摘要】：自20世纪50年代电子技术开始应用于汽车行业以来，汽车的电子控制系统结构变得日益复杂。我们在享受电控系统所带来的汽车动力性能、安全性能等不断地提高的同时，又要面临汽车故障种类变多、汽车发生故障可能性增大、对汽车故障类型及发生位置的诊断也越来越困难等问题。目前汽车的诊断维修更加的倚重电子化、电脑化的专业诊断系统，汽车故障诊断仪己经成为诊断过程中必不可少的设备，其需求也越来越大。针对现有汽车故障诊断仪存在缺点与不足，结合Android智能手机庞大的用户量以及具有的越来越强大的运算处理能力、支持丰富的硬件资源、简单直观的图形化操作界面、方便快捷的上网等优点，本文设计并实现了一种基于Android智能手机的汽车诊断系统。本文所研究实现的诊断系统，，通过OBD-II通用诊断接口ELM327与汽车的OBD系统进行通信，从而读取汽车实时的运行参数以及故障参数。该诊断系统通用性较强，可适用于绝大多数车型。车主可以通过本系统查看汽车的实时信息、周围修理厂信息，申请远程故障诊断、道路救援服务，还可以对汽车的加油、维修保养等信息进行管理。为实现本系统，本文所做的主要的研究如下： (1).重点研究了车辆数据的获取与上传。首先是通过智能手机传感器获取汽车加速度以及行驶方向；其次是汽车OBD系统中的数据的获取过程，并且从数据的实时性以及冗余性考虑，设计了一个数据的动态采集策略；最后是数据上传，针对实时上传，采用MQTT推送的方式来实现，而针对手动上传，设计了一种新的数据存储格式，从而减少存储空间。 (2).对系统中所涉及的关键点进行了针对性研究。首先根据获取到的汽车的数据，给出了故障诊断、油耗分析和危险驾驶预警分析，从而更好地服务于车主；其次针对数据的网络传输进行研究，主要包括对JSON格式的交互数据的解析，采用双重MD5加密来确保密码等敏感数据传输的安全性，引入异步网络传输机制使耗时的网络数据传输操作能够正常的执行。 (3).设计并实现了一个基于Android智能手机的汽车诊断系统。主要研究了系统整体架构的设计、功能模块的设计以及数据存储方案的设计，并针对系统的功能模块的设计，详细介绍了该诊断系统各个子功能模块的系统界面的设计以及相应功能的实现。
[Abstract]:The electronic control system structure of automobile has become more and more complicated since the electronic technology began to be applied in automobile industry in the 1950s .

This paper studies the diagnosis system realized in this paper , and communicates with the OBD system of the automobile through the OBD - II universal diagnostic interface ELM327 , so as to read the real - time operating parameters and the fault parameters of the automobile . The diagnosis system has strong universality and can be applied to most models . The owner can view the real - time information of the automobile , the information of the surrounding repair plant , the application of remote fault diagnosis and road rescue service through the system , and also can manage the information such as fuel filling , maintenance and the like of the automobile .

In order to realize this system , the main research done in this paper is as follows :

( 1 ) the acquisition and uploading of the vehicle data are mainly studied , firstly , the vehicle acceleration and the traveling direction are acquired through the smart phone sensor ;
Secondly , it is the acquisition process of the data in the automobile OBD system , and the dynamic acquisition strategy of data is designed from the real - time and redundancy of the data .
Finally , the data upload is realized in the way of MQTT push for real - time upload , and a new data storage format is designed for manual upload , thus reducing storage space .

( 2 ) The key points involved in the system are studied . Firstly , according to the acquired data , the fault diagnosis , fuel consumption analysis and dangerous driving early warning analysis are given , so as to better serve the vehicle owner ;
Secondly , the research on the network transmission of the data mainly includes the parsing of the interaction data in JSON format , the double MD5 encryption to ensure the security of the sensitive data transmission such as the password , and introduces the asynchronous network transmission mechanism to enable the time - consuming network data transmission operation to be performed normally .

( 3 ) Design and implement an automobile diagnostic system based on Android smartphones . The design of the system ' s overall architecture , the design of functional modules and the design of the data storage scheme are studied , and the design of the functional modules of the system is discussed in detail . The design of the system interface and the realization of the corresponding functions are introduced in detail .

【学位授予单位】：中国海洋大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U472.9;TN929.53

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