全喂入花生捡拾收获机喂入量建模与试验

为解决中国全喂入花生捡拾收获机作业时因喂入量波动导致作业性能下降甚至出现机械故障,而花生捡拾收获机喂入量相关基础研究又缺失的问题,该文以团队前期所研制的4HLJ-3000型全喂入花生捡拾收获机为研究对象,提出了基于捡拾台动力输入轴扭矩的喂入量监测方法。通过对捡拾台进行动力分析,得出了捡拾台动力输入轴扭矩和喂入量的数学模型。利用捡拾台动力输入轴转速、扭矩和功率等工况数据监测存储分析管理系统进行了扭矩和喂入量的道路监测试验。对试验结果进行了线性函数、幂函数、指数函数和二次函数拟合回归分析,结果表明二次函数模型拟合度较高,其决定系数R2为0.990。对二次函数拟合曲线进行分析,结果表明,当喂入量小于等于3.0 kg/s时,随着喂入量的增加扭矩缓慢增加;当喂入量大于3.0 kg/s时,随着喂入量的增加,扭矩急剧增加,且转速随之降低。模型验证试验的结果表明,所建立的二次函数模型具有较好的准确性,绝对偏差率范围为0.42%～2.43%,平均偏差率为1.40%,且喂入量越大,偏差率越大。对喂入量和扭矩的函数模型进行了田间试验,结果表明,扭矩偏差率范围为1.90%～3.58%,平均偏差率为2.65%。研究结果可为全喂入式花生及其他作物捡拾收获机结构优化设计及喂入量的智能测控提供参考。

Modeling and experiment of feeding rate for full-feed peanut pickup harvester

In order to solve the problem of performance degradation and even mechanical failure caused by fluctuation of feeding rate during the operation of full-feed peanut combine harvester in China, and the lack of basic research on feeding rate of full-feed peanut combine harvester, the structure and working principle of the pickup bench of the 4HLJ-3000 full-feeding peanut combine harvester developed by the author team were analyzed in this paper. The pickup bench is mainly composed of limited depth wheel, pressure rod, slide plate, pickup elastic teeth and screw conveyor. Based on the analysis of structure and working principle, a monitoring method of feeding rate based on the torque of power input shaft of pickup bench was proposed. Through the force analysis of the pickup bench, the mathematical relationship between the power input shaft torque and the feeding rate of the pickup bench was obtained. A working condition monitoring system of the speed input, shaft speed, torque and power of the power input shaft was designed, and the system was mainly composed of sensor unit, data acquisition, and data storage analysis. The sensor unit converts the torque and speed of the power input axis of the pickup bench into frequency signals, and the data acquisition module converts the frequency signals into torque and speed values and displays them, and transmits them to the computer for storage and analysis through RS485 bus and RS485 to USB. The data of torque and rotate speed of pickup bench power input shaft, forward speed of pickup harvester and feeding rate were obtained in different operating conditions by road monitoring tests. Linear function, power function, exponential function and quadratic function fitting regression analysis were used to obtain the function indicated the change of feeding rate with various torque based on the test results. The results showed that the quadratic function model had higher fitting precision, and its determination coefficient was 0.990. The fitting curve of quadratic function was analyzed, and the results showed that when the feeding rate was less than 3kg/s, the torque increased slowly with the increase of feeding rate, while the torque increased sharply and the rotation speed decreased with the increase of feeding rate. The model verification experiments were proposed, and the results showed that the established quadratic function model had good accuracy. The absolute deviation rate ranged from 0.42% to 2.43%, and the average deviation rate was 1.40%. The deviation rate increased with increasing the feeding rate. The field experiments also proved that there was a quadratic function relationship between feed rate and torque, and the torque deviation rate ranged from 1.90% to 3.58%, and the average deviation rate was 2.65% compared with the calculated results. This study can provide reference for the optimization design of the structure of full-feeding peanut picker and other crop pickers and the intelligent measurement and control of feed rate.