关键词: 离散元方法, 压电传感器, 小麦, 损失监测

Abstract: Aiming at the problems of complex structure and high cost of the wheat loss monitoring sensor, the motion characteristics of different materials in the harvester cleaning and discharging port were studied, and the law of the impact of wheat and straw on the sensitive plate was revealed. Based on the mechanical properties, an experimental device for monitoring the cleaning loss of wheat harvester was designed. The discrete element analysis software EDEM was used to analyze the force generated by the impact of wheat grains, 50 mm straw and 100 mm straw on the sensitive plate, and the change curve of the contact force was analyzed. In order to enhance the accuracy of signal acquisition, two piezoelectric sensors were connected in series, which increased the signal of loss. The mechanical structure and control system of the loss monitoring test bench were designed, so that the monitoring device simulated the cleaning and removal process of the harvester and could monitor the signal in real time, which effectively improved the monitoring efficiency. Finally, through the monitoring test of material movement loss at different heights, it was concluded that the sensor recognition was more accurate at a height of 300 mm, the recognition rate of wheat grains reached 98.4%, and the overall monitoring error was less than 5%. The loss monitoring test device can meet the design purpose and requirements.

Key words: discrete element method, piezoelectric sensor, wheat, loss monitoring