摘要在今天，大多数的倒车雷达运用超声测距和单片机智能技术结合，在汽车电子 领域中得到了广泛的应用。但是其中大部分产品仅是独立的控制单元，没办法与 车载的 CAN 网络连接。论文在研究倒车超声测距原理和倒车雷达软硬件设计的基 础上，设计了倒车雷达系统中的车载 CAN 总线智能节点，从而实现倒车雷达在各 个智能节点单元之间的资源共享和数据通讯。我主要完成的工作有:   73768

1。调研国内国外倒车雷达历史、发展、现状，对超声测距原理，还有所用超声 波传感器的特性和原理进行简单介绍。根据系统功能设计的要求，提出系统的总 构成。   

2。倒车雷达部分分为系统控制、发射接收和显示报警模块。本课题以 51 单片 机为主控单元进行系统硬件和软件设计。   

3。利用 C 语言及相关软件完成系统的软硬件设计。   

4。应用 SJA1000 CAN 控制器和 PCA82C250 CAN 收发器设计倒车雷达 CAN 总线 智能节点，使其与车载 CAN 网络连接。给出 CAN 总线接口电路图，以及通讯报文 等相关设计。   

5。论文需要完成倒车雷达及其车载 CAN 总线智能节点的软硬件设计及在条件 允许情况下进行系统调试。尽可能达到预期设计的课题技术指标，具有较高的测 量精度和可靠性。在倒车雷达的设计上，具有一定的指导意义，并且在 CAN 总线 通讯报文设计、车载 CAN 网络功能扩展上，具有广泛的实用意义和应用前景。   

毕业论文关键字:超声测距；倒车雷达； CAN 总线智能节点；通讯报文 

毕 业 设 计 说 明 书 英 文 摘 要 

Title      Design of intelligent node for car backing radar based on CAN bus 

ABSTRACT   

Nowadays, most of car reversing radars using ultrasonic principle and MCU intelligent technology are widely used in the field of automotive electronics。 Most of them operate only as an independent control unit, and are unable to be connected to the CAN networks of vehicle。 Researching on the ultrasonic ranging, hardware and software design of the car reversing radar, this paper designs a CAN-bus intelligent node。 

The main works completed by the author of the paper include: 

1。 This paper investigates the present level and progress of the car reversing radar。 By introducing the development and theory of ultrasonic ranging, also the theory and characters of ultrasonic sensor, the paper proposes the system general structure based on its function。 The   introducing in two parts: car reversing radar and its intelligent node based on CAN-bus of vehicle。 

2。 The parts of car reversing radar consist of three modules: ultrasonic emitter and incept module, control module and display-alarm module。 It presents the design of the hardware and software based on the MCU 51。  3。 The software design is completed by assembler language and Keil。 4。 An intelligent node of CAN-bus for the car reversing radar is designed, using the SJA1000 CAN controller and the PCA82C250 CAN transceiver, so that the radar can be integrated with the CAN networks of vehicle。 Then， the paper gives the CAN-bus interface circuit, as well as communication messages and software design。 Its feasibility is verified by experiments。  5。 Both the hardware and software design of the car reversing radar which based on ultrasonic ranging and CAN-bus of Vehicle, has competed, so as the system debugging。  The results of experiments show that, the design 

is able to reach the anticipated technical indicator and has higher precision and stability。 The issue offers the foundation for the car reversing radar designing, and has broad application prospect and practical value in the communication messages design, so as the extension of vehicle CAN networks。