Research on the Fault-Diagnosing Method in the Operation of the Threshing Cylinder of the Combine Harvester

Combine harvester is operated in the complex and changeable working environment, with heavy load and long working time. During the working process of the combine harvester, many problems including too fast the operation speed and the uneven feeding amount could cause blockage of the threshing cylinder, affecting the working efficiency, and causing great damage to the combine harvester. Blockage of the threshing cylinder can be found out through observing rotate speed and torque. Previous fault diagnosis methods only diagnosed the rotate speed without considering impacts from other parameters. These methods easily underreport faults and have limited diagnostic capabilities. In this paper, a multi-parameter trend-change fusion analysis method based on the instantaneous change trend of the target signal was proposed to comprehensively analyze the rotate speed and torque. The rules of early warning and alarming of the jam fault were also defined: an alarm is issued when the rotate speed is less than 40% the upper limit and the torque is greater than 70%, and a warning prompt is given when the fault judgment value $I$>0.01. With the corn combine harvester as the analysis object, experiments show that the proposed fault-diagnosing method can effectively distinguish the real jam and false jam in the early warning, and give the early warning prompt and alarm in time without false alarm or underreport. The proposed method can help to reduce the number of stoppages during the operation caused by false alarm and the damage caused by underreport. It can improve the operation efficiency and save maintenance costs.