【作者】 尹彦鑫；

【导师】 谭彧； 郑永军；

【作者基本信息】 中国农业大学 ， 机械电子工程， 2014， 博士

【摘要】 少免耕播种机作为能够在作物秸秆覆盖地上直接进行播种和施肥的机具,是保护性耕作的关键农业装备,成为近来研究和发展的重点。少免耕播种机作业时其能耗和作业效率很大程度上受到土壤牵引阻力的影响,通过检测其作业过程中动力等参数来分析其工作效率及能耗情况成为一种有效途径。目前针对农业机械受力监测主要采用有线方式,这种方式会带来一些问题,比如布线困难,田间恶劣工作环境造成线缆损坏,较长的线缆造成传感器信号衰减,以及可扩展性差等。此外,针对少免耕播种机工作性能的检测设备很少,这给少免耕播种机工作性能的实时检测和研究造成了极大的困难。本文围绕少免耕播种机作业过程中所受动力和速度等参数,开发了基于无线传感网络技术、嵌入式技术和计算机测控技术的少免耕播种机信息流远程监测系统。本课题研究思路是采用无线传感网络,对少免耕播种机的每一个检测位置都部署一个具备数据采集和传输能力的无线网络节点,各个网络节点对对应的传感器进行数据采集,然后将数据以无线方式传输至一个汇聚节点上,汇聚节点再将数据批量传输至现场便携式无线数据检测仪进行现场监测,监测仪再将数据转发远程到远程计算机监控中心,由监控中心对播种机作业动力参数进行数据处理、在线分析、实时显示以及批量存储等,实现少免耕播种机作业动力参数的近、远程同步监测。通过分析少免耕播种机悬挂机构的受力,提出其作业过程空间受力、旋转动力以及作业速度等参数的检测方法。设计二维轴销式测力传感器对播种机作业所受牵引力进行检测,此外还利用门架式六分力测力机构实现对其悬挂机构所受空间力的检测。设计动态转矩传感器实现对播种机作业中所受旋转动力检测。利用差分GPS速度传感器对播种机作业速度参数进行检测。构建了基于Zigbee的无线传感网络,用于对少免耕播种机信息流数据进行采集和无线传输。利用无线传感网络仿真工具Truetime在Matlab/Simulink环境下建立无线传感网络仿真模型,对本系统构建的少免耕播种机信息检测无线传感网络进行仿真,分析了数据丢包和网络时延对检测系统的影响。利用基于Zigbee的无线模块设计研制可配置型无线数据采集器,并将其组成无线传感网络进行少免耕播种机3点悬挂结构受力、动力输入轴转矩和转速以及作业速度等信息的采集和无线传输。采集器具备多通道采集能力和通道复用功能,其数据采集和无线传输软件运行在支持Zigbee协议的BoS系统上,利用滑动滤波算法对采集的模拟量数据进行滤波处理,通过改进频率测量的测周期T算法,实现对频率量的精确采集。经计量,采集器模拟通道采集精度达到0.04%,频率量采集误差为0。研制了基于嵌入式ARM技术的便携式无线数据检测仪,该监测仪具备两级无线传输、移动信息监测和便携易安装等特点。其配备一块7时触摸显示屏,以触控方式进行人机交互。检测仪内部集成一个Zigbee协调器,接收无线传感网络中各个数据采集器节点的数据,ARM核心处理器进行数据处理,再通过远程无线传输模块XTend(?)(?)数据传输至远程计算机监控中心。利用嵌入式WinCE6.0操作系统作为监测仪软件运行环境,开发了基于多线程技术的监测软件用于接收处理来自无线数据采集器采集的播种机参数。开发了计算机远程监测软件,软件包含5个子系统,即人机交互、后台数据处理、数据批量存储、历史数据查询以及其它辅助功能。人机交互界面利用MFC类库开发,后台数据处理采用了多线程技术和重叠IO技术,实现少免耕播种机作业信息参数的高效处理,数据批量存储利用线程同步技术分时批量存储数据。计算机远程监测软件可对无线数据采集器节点的网络状态进行动态监测,根据实际需要可对指定采集器节点的工作参数进行远程配置。在研究和开发的基础上,将该少免耕播种机信息流远程监测系统分别应用在玉米、小麦免耕播种机上进行多次试验,试验结果表明：试验数据曲线反映了少免耕播种机作业动力的变化趋势,表明该系统能够对少免耕播种机作业中的动力参数进行现场和远程监测。与其他测试系统相比,该系统使用方便,降低了田间测试的复杂程度,为少免耕播种机的监测和研究提供了良好的技术支持。更多还原

【Abstract】 As one of the directly seeding and fertilizing machines for the crop straw covering ground, the no-tillage seeder is the key equip in the conservation tillage agriculture equipment and has become the focus of recent research and development. The energy consumption and efficiency of no-tillage seeders is directly influenced by soil traction resistance to a large extent, so it is an effective way to analyze the efficiency and energy consumption by using the dynamic parameters in the operation process. The traditional wired methods of measure need lay the cable, which is complex, and the adjustment, expansion, and maintenance of the measuring points are inconvenient. In addition, few testing equipments specially used for no-tillage seeder make more difficulties for the real-time detection and the research of the no-tillage seeder working performance. Based on wireless sensor network technology, embedded technology and computer measurement and control technology, the no-tillage seeder information remote monitoring system was developed by analyzing the parameters in the no-tillage seeder operation process, such as power and speed.The research ideas were intended to monitor no-tillage seeder dynamic parameters and realize the near distance and remote monitoring using wireless sensor network. Wireless sensor network is a kind of self-organizing network, which is composed of many small nodes, and can be used for sensing, testing, collecting signal processing and controlling. Nodes were installed in each test positions to gather and transfer data, and can acquire and process sensor data, then finally send the data to the data gathering node. Data gathering node transfers the bulk data to the scene of the portable wireless data monitor for on-site monitoring. The portable wireless data monitor again transferred the data to the remote computer remote monitoring center by wireless sensor networks based on wireless multi-hop routing for data processing, online analysis, real-time display and mass storage, etc.An operation process parameters testing method for space force, rotating dynamics and operation speed groundwater advection was proposed, by analyzing the forces of no-tillage seeder suspension mechanism. A two-dimensional shaft pin force-measuring sensor was designed to test the traction in the sowing and using six component force measuring mechanism to test the space force of the suspension mechanism. Dynamic torque sensor is designed for machine operation by rotating the power detection and using differential GPS speed sensor to test the drill operation speed parameters.The Zigbee wireless sensor network is constructed for data acquisition and wireless transmission of the no-tillage seeder. A wireless sensor network simulation model is established by using wireless sensor network simulation tools Truetime under the Matlab/Simulink environment, which is used to simulate wireless sensor network system of the no-tillage seeder information detection, analyze the data packet loss and the influence of network delay on the detection system.Based on the Zigbee wireless module, configured type wireless data collectors was designed, which can be used for information acquisition and wireless transmission, such as no-tillage seeder for less3points suspension structure, power input shaft torque and rotational speed and operating speed. Configured type wireless data collectors had the capability of multi-channel acquisition and channel multiplexing function, whose data acquisition and wireless transmission software running on the BoS system supported by Zigbee protocol. What’s more the configured type wireless data collectors were used sliding filter to filter the acquisition of analog data, and realize the frequency accurately, by improving the measuring period T algorithm of frequency measurement. Appraised by China’s Institute of Metrology, Beijing, the analog acquisition error is less than or equal to0.04%and frequency signal gathering error is0.A portable wireless data monitor based on embedded ARM was developed, which has many advantages, such as two levels of wireless transmission, mobile information monitoring, portable and easy to install. The portable wireless data monitor with a piece of7inch touch screen allows the operator operating in a touch way. In the detector installed a built-in Zigbee coordinator to receive data from various data collector nodes in a wireless sensor network. The ARM core processor was used to processing data, and sent the data to the remote computer monitoring center through the remote wireless transmission module XTend. The drill parameters monitoring software, which runs in the embedded WinCE6.0operating environment, based on multi-threading technology was developed to process the data from the wireless data collector.A remote monitoring software was developed, which included five subsystems, namely, human-computer interaction, the background batch data processing, data storage, historical data query and other auxiliary functions. To efficiently process the no-tillage seeder operation information parameters, using MFC class library developing the Human-computer interaction interface, and using the multi-thread technology and overlapped I/O technology processing the background data and using the multi-thread synchronization technology storing the data time oriented. The remote monitoring software can dynamical monitor the network status of the wireless data terminal nodes, and it can configure the collector node working parameters in a long-distance according to the actual need.Various a serial of tests had been done by installing the no-tillage seeder remote monitoring system on corn and wheat no-tillage seeders, and the results showed that:tests data described the variation trend of tractive force that the no-tillage seeder loaded, which indicated that the system could realize information monitor both in short and long distance for no-tillage seeder. compared with other detecting systems, this system reduced the field test complexity for no-tillage seeder, which supplied a better and more convenient method for researchers to study no-tillage seeder.更多还原