Research and development of automobile body control system based on CAN bus Chengdu Panfeng Technology

With the development of the modern automobile industry and people's increasing requirements for automobile power systems and safety and comfort systems, automobile electronic control units and electronic equipment are also increasing. This has led to the geometric growth of the wiring harness in the car, making it increasingly difficult to wire in the limited space inside the car, limiting the expansion of the car's internal control functions, and increasing manufacturing and maintenance costs. Traditional wiring harnesses are far from meeting the requirements, and automotive LANs emerged as the times require. The emergence of automotive networks not only solves the increasingly complex wiring harness layout problem, but also brings a qualitative leap to the optimal control of automobiles.
This text first introduces the current status and development trends of automotive electronics technology in the world, and fully analyzes the performance and characteristics of several currently popular fieldbuses. And according to the needs of the research of the automobile body control system, with reference to
bus technical specifications and high-speed serial communication protocol
B
, a
bus application layer communication based on the body control module was formulated The protocol divides the entire body control system into five node modules for implementation. They are respectively the main node, the left door node, the right door node, the front node of the body, the rear node of the body, the remote control central door lock and anti-theft, electric windows and sunroof glass. Control functions such as lift, interior and exterior lights, headlight follow
(
Additional light group
)
, wipers, rear window and rearview mirror heating.
This article also makes a more detailed discussion on the design ideas of the body control module hardware and software of the
bus body control system, and draws the power drive circuit of each module of the body, and uses
language to write data The control communication program implements node communication, that is, the node communication transceiver program and interrupt program. Finally, a verification experiment for the application layer protocol was conducted on the system.
r has the advantages of strong real-time performance, long transmission distance, strong anti-electromagnetic interference ability, and low cost.
br br
br br Adopts two-wire serial communication method and has strong error detection ability. Can work in high noise interference environment
r has priority and arbitration functions, multiple control modules are hung on
b
r through
br br controller to form multiple hosts The local network
br br can decide to receive or block the message according to its
r
br brReliable error handling and error detection mechanism After the information sent is damaged, it can be automatically restarted The sending node has the function of automatically exiting the bus in case of serious errors
br brThe message does not contain the source address or destination address, and only uses identifiers to indicate function information and priority information.