基于卷压力的圆捆机成捆密度监测系统设计与试验

针对当前国内圆捆机信息化程度低，草捆密度缺乏有效监测手段等问题，研究设计一种圆捆机成捆密度监测系统，依据测量草捆成捆过程中的卷压力，建立卷压力与成捆密度之间函数模型，实现对成捆密度的实时监测。监测系统主要由控制器、信号采集模块、通信模块、显示模块以及电源模块等部分组成，根据卷压力采集装置和侧拉力采集装置，实现对圆捆机多个作业参数的监测；搭建试验台，开展成捆密度监测系统打捆性能试验，分别以卷压力和侧拉力作为成捆指标，对成捆密度进行监测，对比其差异性；进行小麦秸秆压缩规律试验，建立草捆成捆过程中卷压力与密度之间函数模型，并根据多次打捆试验对函数模型进行验证。试验结果表明：1）基于卷压力的圆捆机成捆密度监测系统，可以实现对圆捆机成捆过程中作业参数的采集监测；2）以卷压力作为成捆指标时，成捆密度最大偏差为4.38%，变异系数为3.12%，与侧拉力相比，基于卷压力的密度监测方法能够更为准确地反映成捆密度；3）含水率为15%的小麦秸秆在打捆过程中卷压力与密度之间的关系符合二次函数模型，相关系数为0.983，计算值与测量值之间的最大偏差为5.06%，成捆密度监测模型能够准确反映卷压力与密度之间的关系。综上，利用本监测系统可实现草捆成捆密度的实时监测，为圆捆机成捆密度控制提供参考。

Design and experiment of density monitoring system for round baler based on rolling pressure

In response to the current problems of the low degree of informatization of domestic round baler and lack of effective monitoring means for bale density， a set of bale density monitoring system for round baler was designed in this study. The real-time monitoring of bale density is realized by measuring the roll pressure during the bale forming process and establishing a function model between roll pressure and bale density. The monitoring system is mainly composed of controller， signal acquisition module， communication module， display module and power supply module， etc. It realizes the monitoring of several operational parameters of the round baler through the roll pressure acquisition device and side tension acquisition device. In this study， a test bed is set up to carry out the bale performance test of the bale density monitoring system. Bundle density is monitored by using roll pressure and side tension as bale formation indexes to compare the differences respectively. This study conducted tests on the compression law of wheat straw， established a function model between roll pressure and density in the bale forming process， and verified the function model based on several bale tests. The results show that： 1） The bale density monitoring system of round baler based on roll pressure can realize the collection and monitoring of operational parameters during the bale forming process of round baler. 2） The maximum deviation of bale density is 4.38% and the coefficient of variation is 3.12% when using roll pressure as the index of bale formation. The density monitoring method based on roll pressure can more accurately reflect the size of bale density compared with the side pulling force. 3） The relationship between roll pressure and density of wheat straw with 15% moisture content in the baling process is in accordance with the quadratic function model， the correlation coefficient is 0.983， and the maximum deviation between the calculated value and the measured value is 5.06%， which makes the compression model able to accurately reflect the relationship between roll pressure and density. In conclusion， the monitoring system constructed in this study can realize the real-time monitoring of the bale density. This study provides a reference for the bale density control of round baler.