Design Of Vehicle Electronics Drive Unit Based On CAN-Bus

Abstract In recent years, with the fast-forward development of China's auto industry, the most striking is the growing Chinese automotive consumer market.The international major automobile manufacturers compete for a place, only to continuously reduce cost of production, improve product quality in this vast market. By continuously increasing the technology content of automotive design in order to continuously meet the people's needs, so the field of automotive electronics design of a vehicle becomes an important branch because of its importance and prominent significance. This design is to respond to this new research field of automotive electronics,based on this important technology to complete the automotive lighting control system and window control system design.The design uses the LPC2129 chip as the core microprocessor, mainly because LPC2129 chip is 32-bit microprocessor, Its processing speed is very fast; In addition, its rich peripheral hardware resources provide great convenience for the system design.The second chapter of Paper focuses on the hardware circuit design, and gives a concrete circuit diagram and the electrical characteristics of devices used, including power supply circuit, crystal oscillator and reset circuit, memory systems, debug circuits, serial design, CAN Bus Transceiver Controller PCA82C250 circuit schematic diagram, lighting and the two-phase stepper motor power amplifier circuit. Design of the hardware circuit is very important, closely related to the the success of the implementation of the entire design. So in the initial stages of the design, the author spends a lot of time and effort to studies the hardware circuit in order to prevent some problems.The design is based on CAN bus. The third chapter focuses on the CAN bus message types and formats, CAN bus transmitting and filtering issues. CAN-bus belonging to the physical layer and data link layer of ISO / OSI reference model.The third chapter also gives a detailed analysis of CAN bus.Understanding of some of the basic elements of CAN bus is necessary for application. CAN driver procedures, including CAN bus initialization procedure, receiving data and sending data procedure, are given in the paper, including related notes, for more profound understanding of this design. The communication based on CAN bus, defines the lighting control system and window control systems, command data frame of meaning, the meaning of return frame and set of the acceptance filter, which is applied to achieve the CAN bus, the most critical part of the design.In lighting control system, this design uses National Semiconductor's LM3421 lighting driver chip, National Semiconductor Corporation provides a very complete solution for automotive lighting system. After repeated research and comparison, LM3421 driver IC can be a very good lighting to meet the design requirements. while, LM3421 manual chip provides a variety of forms of driver circuits, you can choose the most flexible of the driver circuit to meet the design requirements.Window Control System uses THB6064H driver chip, which provides precise control of motor rotation steps of two-phase stepper motor in the window control, to meet the design requirements. Regulating the motor rotation steps by controlling the number of PWM pulses, controling the motor rotation speed by controlling the PWM pulse frequency, so as to achieve the purpose of precise control of the window. Chip manual shows a typical application circuit and attentions applied to this design.Lock drive system includes remote controling part of the design and the driving motor circuit. Remote transceiver control uses F05V/J04V supporting chips. Driving motor circuit uses L298 DC motor driver chip to control the opening and closing of locks. The current state of locks transmit to the display unit through the CAN bus.In the CAN bus applications, the CAN bus debugging part gives some of the problems and solutions, which are summed up in the debugging process in what I hope for being helpful to the future study of CAN bus.