谷物联合收获机压力式在线测产系统设计与试验

Design and Experiment of Pressure Type Online Yield Measurement System for Grain Combine Harvester

摘要:

为了提高谷物联合收获机在线测产精度并抑制测产过程中车身倾斜与机械振动的干扰，设计了一种基于倾角与振动补偿策略的压力式谷物测产系统。该系统由压力式谷物测产装置、GNSS定位模块、数据处理器和上位机组成。首先基于谷物产量与传感器压力、倾角、振动、含水率的函数关系构建谷物产量监测数学模型，并搭建了谷物产量监测试验台架，通过正交试验结合响应面分析法优化装置结构参数。研究了压力传感器数量、消振器安装位置和测产装置倾角对测产误差的影响，并确定最优参数组合：压力传感器数量为5、振器安装位置为第3参考位置（距左槽壁175mm处）、装置水平倾角为21°。台架单变量（流量变化）与多变量（流量、倾角及振动变化）试验结果表明，不同工况下20组试验的测产误差稳定控制在3%以内；田间试验结果表明，实际作业中平均测产误差为3.41%，最大不超过4%，验证了系统可有效抑制车身倾斜与机械振动对测产精度的干扰，可为精准农业产量分布信息获取提供有效技术支撑。

Abstract:

In order to improve the online yield measurement accuracy of grain combine harvester and suppress the interference of body tilting and mechanical vibration during the yield measurement process, a pressure-type grain yield measurement system based on tilting angle and vibration compensation strategy was developed. The system consisted of a pressure-type grain yield measurement device, a GNSS positioning module, a data processor and a host computer. Firstly, a mathematical model of grain yield monitoring was constructed based on the functional relationship between grain yield and sensor pressure, inclination, vibration and humidity, and a test rig for grain yield monitoring was built to optimize the structural parameters of the device through orthogonal test combined with response surface analysis. The effects of the number of pressure sensors, the mounting position of the vibration absorber and the inclination angle of the device on the measurement error were investigated, and the optimal parameter combinations were determined to be five pressure sensors, the 3rd reference position (175mm from the left slot wall) for the vibration absorber and the 21°inclination angle of the device, respectively. The results of univariate (flow rate change) and multivariate (flow rate, inclination angle and vibration change) tests showed that the yield measurement error of 20 groups of tests under different working conditions was stably controlled within 3%;the results of field tests showed that the average yield measurement error in actual operation was 3.41%, with a maximum of no more than 4%, which verified that the system can effectively inhibit the interference of the tilting of the vehicle body and the vibration of the machinery on the accuracy of the measurement of the yield and provide an effective technical support to obtain the information of the distribution of the yield of the precision agriculture. The system can effectively suppress the interference of body tilt and mechanical vibration on yield measurement accuracy, and provide effective technical support for the acquisition of precise agricultural yield distribution information.