Construction Machinery Embedded Fault Diagnosis Device

Construction machinery has been widely used in various types of construction projects. Construction machinery has features of great power and high efficiency. But the construction machinery system is very complex, involving extensive professional knowledge,if it is failure to find out the fault origin timely, the repair and maintenance will affect the progress of the project,accordingly affect efficiency. So selecting an appropriate and efficient fault diagnosis method have great significance to improve system reliability and security.This paper uses the OBD-Ⅱfault diagnosis method in the construction machinery,to achieve real-time fault diagnosis ,by reserching on fault diagnosis of excavator and OBD-Ⅱ. OBD is the English abbreviation of On-Board Diagnostics which is translated for "Car auto diagnostic system "in Chinese.The paper gaves a detailed description on fault diagnosis method of construction machinery,reserches on the OBD-Ⅱdevelopment and application, determines the diagnosis communication protocol based on CAN bus with depth study on OBD-Ⅱcommunication protocols and diagnostic mode.The hardware design constructs hardware system of diagnostic equipment based on TMS320F2812 , including power module, JTAG module, CAN communication module, SCI serial communication module, the keyboard module, LCD module display. The principles and PCB design of hardware hardware were accomplished in the hardware environment of Protel DXP 2004. A detailed introduction was done with board layout, routing, spliting power planes and ground settings of four layers PCB (printed circuit board).Software system are divided into several function modules: the main function module, serial communication module, CAN communication module, keyboard input module, fault code processing module and LCD module. The paper analysises the major functions of each module with design ideas and implementation. The function was realized by programming in C language,which was written,debugged and finally programmed into the DSP chip in CCS3.3.Finally, the paper summarizes the work done , gives a outlook for future development and unresolved issues,and analyzes the following work.