Abstract:The integrated virtual testing system for tractor economy performance was designed, which aimed to meet the research requirements on the tractor fuel and energy saving technology, the power assembly design optimization, the agricultural operation standard determination, etc. Firstly, the hardware lectotype was determined based on the requirement analysis of tractor fuel consumption test. Then the test system based on NI cRIO controller was designed, which can complete the synchronous acquisition of instantaneous fuel consumption, fuel consumption per 100 km, velocity, driving path and engine working state parameters, etc. Consequently, the virtual software design of the test system was described in detail, including FPGA software, realtime software and PC data acquisition and analysis software. The X4 encoding programming technology was used to acquire the double TTL signals output by the fuel flowmeter, and the resolution ration for the effective impulse signal could be increased by four times. By means of the determination for fuel forward and backward moving, and the FPGA precisely timing capture for the jump or down edge of the TTL signal, the test accuracy for the instantaneous fuel consumption could be improved effectively. In order to analyze the engine work state, the CAN and K line from OBD interface were connected to the test system and the relative programming was made to acquire the engine output torque, the engine speed, etc. Finally, according to the comparison tests and field tests, the samples and data processing methods employed in the system for instantaneous fuel consumption were accurate and in realtime. Besides, the whole system function and reliability were also validated. The study of this paper provides an effective means to comprehensively evaluate and analyze the tractor economy performance.
