中文摘要：

基于虚拟仪器构建了拖拉机经济性综合测试系统,以满足拖拉机节油节能技术、动力总成设计优化、农艺规范优化等研究测试需要。首先在分析拖拉机油耗测试要求的基础上,对硬件进行选型,设计了以美国NI cRIO控制器为核心的测试系统,实现对瞬时和百公里油耗、行驶速度和轨迹、发动机工作点等信号同步采集。给出了测试系统的虚拟软件设计方案,包括FPGA软件、实时软件和上位机数据采集与分析软件等。对油耗流量传感器输出的两路正交编码TTL信号进行X4编码编程,将有效方波信号计数分辨率提高到0.25个方波。编程实现系统对燃油正、回流识别和计数,采用FPGA精确定时技术确定计数脉冲边沿跳变时刻,有效提高了瞬时油耗测试精度。将发动机OBD接口中的CAN和K线接入系统,并编程实现对发动机输出扭矩、转速等信号的同步采集,以分析发动机工作状态。最后进行了对比试验和场地试验,验证了本系统瞬时油耗采样和数据处理方法的准确和实时性,以及整个系统功能和可靠性。研究为拖拉机经济性综合评估和分析提供了有效手段。

英文摘要：

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,real-time 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 fuelconsumption were accurate and in real-time. 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.