Development Of E-Car's Door Controlling System Based On CAN Bus With Slow Speed

With the rapid development of electronic information technology and strong growth in automobile manufacturing, systems for controlling car's doors supported by electronic information technology has played a very important role. Currently, controlling system for car's doors made in our country has adopted an electric system in a way of point-to-point and parallel control, with the following defects:(1) Extension of its function will lead to a larger amount of electronic devices, a complicated wiring harness and difficult installation for wiring, it will even make trouble in the process of design, installation, maintenance.(2) Increase in wiring-harness and tie-in will bring about a great number of safety problems.(3) The weight of wiring-harness and increase in holding space will bring about new problems to automobile manufacturing.The thesis discusses E-Car's door controlling system based on CAN bus with slow speed, proposes a design project, designs a hardware circuit of each controlling unit and composes its software, formulates a coding protocol of CAN bus, acquires the characteristics of blocked car's windows through the analysis and test of the E-car's window, and brings forward a method of guarding against window blocking, conducts a systematic design of electromagnetic compatibility, intensifies its capability of system's anti-interference, and makes the debug and experiment of entire system.The controlling system not only fulfils autochthonic control including four car's window sport automatically step by step, two rearview mirrors sport step by step, four locks in every door open/close and a lamp in car dominates, but also realizes the remote controlling of each controlled unit through CAN bus and the function of guarding against window blocking by making use of characteristics of electromotor current of car's window. The experiment shows that the system has overcome the disadvantages of traditional control of automobile's doors, the system can meet the demand of modernized control of automobile's doors and earning a bright future with high reliability stability and low price.