悬挂式旋耕机耕深监测系统设计与试验

Design and Test of Tillage Depth Monitoring System for Suspended Rotary Tiller

针对旋耕机作业耕深测量效率低和缺乏有效在线监测手段的问题,以悬挂式旋耕机耕深为检测对象,研究了一种基于旋耕机悬挂姿态的非线性耕深监测系统,以提高旋耕作业质量自动化监测水平。首先,对旋耕机的悬挂姿态进行分析,确定了旋耕机耕深与悬挂姿态之间的数学关系式,综合考虑悬挂式旋耕机组的结构形变和车轮下陷等因素对测量结果的影响,建立了三参数非线性耕深测量模型,该模型通过拟合旋耕机悬挂姿态角和耕深的关系,可实时计算实际耕作状态下的耕深;其次,为验证该模型的测量精度,设计了适用于车载终端的悬挂式旋耕机耕深监测系统,该系统集成卫星定位、实时耕深测量、作业速度测量、作业面积计算、稳定性评估等模块,支持数据云端存储与共享;最后,对模型参数进行标定试验,采用最小二乘法对模型进行参数优化,利用标定后的耕深监测系统开展多组田间试验。与人工测量结果对比显示,耕深最大误差不超过0.80 cm,均方根误差不超过0.55 cm,表明该悬挂式旋耕机耕深监测系统精度高、稳定性好。通过耕深质量评估试验生成多组带有位置信息的评估报表,表明该监测系统能够对旋耕耕深质量进行全面评估。

Aiming at the problems of low efficiency of depth measurement and lack of effective online monitoring method in rotary tiller operation,a nonlinear monitoring method of rotary tillage depth based on suspended rotary tillage attitude was developed to improve the automation level of rotary tillage quality monitoring.Firstly,the suspension attitude of rotary tiller was analyzed,and the mathematical relationship between the depth and attitude of rotary tiller was established based on the geometric relationship.After comprehensively considering the influence of the structural deformation and wheel subsidence of the suspended rotary tiller group on the measurement results,a three-calibration parameter tillage depth detection model was established.The model can be used to calculate the tillage depth in real time by fitting the relationship between the attitude angle of rotary tiller and the tillage depth.Secondly,in order to verify the measurement accuracy of the model,a rotary tillage depth monitoring system suitable for vehicle terminal was designed.The system integrated satellite positioning,real-time depth measurement,operation speed measurement,operation area calculation and stability evaluation module,and realized the display of the vehicle terminal and cloud storage.Finally,the model parameters were calibrated in the field and optimized based on Matlab.The results of the calibration test showed that the tillage depth value was decreased gradually with the increase of the horizontal inclination angle of the lower link,and the two were negatively correlated,and the tillage depth value was increased gradually with the increase of the horizontal inclination angle of the frame,and the two were positively correlated.A number of field tests were conducted on the calibrated rotary tillage depth monitoring system,and the results showed that the maximum error was 0.80 cm,and the root-mean-square error was 0.55 cm.When the tillage depth was about 11 cm,the measured value was closer to the real value,which happened to be within the reasonable operating depth range of rotary tillage,indicating that the rotary tillage depth monitoring system had high accuracy and good stability.