A simulation model of 2WD tractor performance

The aim of this study was to develop a model that can accurately simulate the performance of a 2WD tractor with a suspended working implement (cultivator) on various types of soil. The following performance indicators were assessed with the use of the developed model: tractor's overall efficiency, tractive efficiency, specific fuel consumption and soil productivity. The proposed model supports the determination of performance indicators accounting for the overall loss of energy during machine operation. Overall efficiency is such an indicator. The value of this parameter varies significantly subject to changes in tractive force from 0 to 7 kN for the analyzed values of the fuel injector control signal and the total transmission ratio in the third (3L), fourth (4L) and fifth (1H) gear. For this reason, the above indicator may be used to determine the optimal parameters of tractor performance. The above variability was not reported in respect of the coefficient of tractive efficiency.     

药品检验标准资料信息综合管理系统

分析了药品标准资料管理现状和读者需求,论述了药品检验标准资料信息综合管理系统的设计思路和建设过程,评价了药品检验标准资料信息综合管理系统的效果。实践证明,该管理系统解决了以往管理和使用中出现的难题,提高了标准资料管理水平和查找效率,促进了药检事业的发展。     

Short- and long-term dynamic accuracies determination of satellite-based positioning devices using a specially designed testing facility

Short-term dynamic accuracy is one of the most significant parameters for agricultural application of satellite-based positioning on straight segments. This is an important characteristic of guidance devices for every user. Two standards are proposed for dynamic testing of satellite-based positioning devices for utilization in agriculture. Previous approaches were typically based on the use of RTK records as a reference for error calculation. A test procedure based on a highly precise testing facility was developed, having a mechanical offset of the test cart less than 0.002 m. The new mathematical approach for straight line segment definition, based on two representative points was developed. This approach enables error-free calculation of off-track errors and determination of U-turn influence based on two additional parameters. Long-term testing was performed (24 h), using a Garmin GPS 18 device for test validation. The obtained results showed that this method can be successfully used for testing dynamic characteristics of GNSS devices. The results were as follows: mean value of the off-track errors was −0.39 m, standard deviation of all measured off-track errors was 1.51 m, being 1.3 m in 95% of the measured off-track errors. The pass-to-pass average error was 0.90 m, being under 0.662 m in 95% of the detected passes. The designed facility and developed procedure can also be successfully applied to the testing of high precision devices, e.g., RTK.     

拖拉机整车振动测试系统的设计

【目的】研究设计拖拉机整车振动测试系统,为拖拉机整车振动特性研究提供平台。【方法】基于DaqLab/2005数据采集装置、LC0201信号调理器、传感器和计算机等,设计拖拉机整车振动信号采集部分;根据振动信号分析处理要求,基于MATLAB,应用频谱分析、小波分析、非线性振动的混沌分析等理论,设计振动信号分析处理部分。【结果】信号采集部分可以根据需要获得拖拉机在不同行驶速度和不同激振频率下的振动加速度信号;振动信号分析处理部分可以对信号进行预处理及相关分析、频谱分析和非线性信号的混沌分析等。采用拖拉机整车振动测试系统对上海-50拖拉机的整车振动进行实测,认为拖拉机整车振动是混沌振动。【结论】设计的拖拉机整车振动测试系统可用于拖拉机整车振动特性的研究。     

虚拟仪器技术在拖拉机性能测试中的应用

采用虚拟仪器技术建立了一套方便而有效的拖拉机性能检测系统,分析了拖拉机的制动力、轴重、车速、灯光、烟度、噪音等检测的原理和实现方法,提出了一套基于多功能数据采集卡(DAQ)和图形化编程语言Labview的虚拟仪器构建方案.从硬件构成和软件功能上对虚拟仪器检测线的功能进行了详细介绍.经实际试验表明,检测仪器具有较高的精度.     

人造板密度在线检测系统的设计

【目的】设计人造板密度计算机在线检测系统,以有效控制和监测人造板产品的质量,满足人造板生产企业发展的需要。【方法】利用现代传感器技术、测试技术、计算机数据处理及控制技术,分别采集人造板材的质量及长、宽、厚等参数,由计算机及数据处理程序计算出所测板材的密度。【结果】实现了对板材密度的快速、在线、无损、动态检测,其检测结果与静态对比试验结果基本一致,可以有效监控人造板产品的质量。【结论】设计的人造板密度在线检测系统高效、经济,实用性较强,易于推广和应用。     

Development of a low-cost attitude sensor for agricultural vehicles

The objective of this research was to develop a low-cost attitude sensor for agricultural vehicles. The attitude sensor was composed of three vibratory gyroscopes and two inclinometers. A sensor fusion algorithm was developed to estimate tilt angles (roll and pitch) by least-squares method. In the algorithm, the drift error of the gyroscopes was estimated using the inclinometers. In addition to tilt angles, the attitude sensor also estimated the absolute heading angle and position with inclination error correction by integrating a GPS. Tests were conducted on a flat field, a sloping ground and a bumpy road. Results showed that the attitude sensor was able to estimate the roll angle with the maximum root mean square error of 0.43°, the pitch angle with 0.61° and the heading angle with 0.64°. Moreover, the attitude sensor dramatically improved the positioning accuracy from 25.9 cm to 3.0 cm in the sloping ground test and from 8.4 cm to 3.7 cm in the bumpy road test. The proposed technology used in the attitude sensor will help to develop advanced agricultural applications.     

桉树测土配方施肥系统的设计与实现

科学施肥是实现作物丰产的有效方式,测土配方施肥则更能体现这种方式。测土配方施肥包括测土和配方两方面。这项技术实施起来比较复杂,主要体现在数据计算上。该文介绍了方便、快捷地计算出具体施肥量的系统。系统采用了养分平衡法和桉树的平衡施肥法计算施肥量,计算结果精确,具有可利用价值。     

Investigation of a system for automatic driving of a tractor unit along interrows of perennial plantings

Theoretical investigations of a system developed and created by a laboratory of the Dagestan Agricultural Research Institute for automatic driving of a tractor (caterpillar) unit while moving along the interrows of orchard and vineyard plantings are carried out.     

基于计算机视觉的实木表面智能化分选系统设计

设计一种集实木传送、图像定位与采集、实木板材表面识别与分选的智能系统,系统通过传送带运送实木板材,CCD摄像头获取板材图像,在触摸屏工控机TPC700-9190T上应用MFC与OpenCV编写分选程序对板材图像进行分析,识别结果通过STM32单片机控制电磁阀完成实木板材的分类。在图像定位与识别算法中,采用积分投影算法确定板材边界,动态采集板材表面图像;在颜色分类方面,利用L*a*b*空间颜色分量的均值、方差和斜度3个低阶矩表达颜色;在缺陷检测方面,提出了基于纹理填充的缺陷分割方法,通过获取纹理掩膜图像,然后利用板材背景颜色淡化纹理,最后应用加权阈值法完成缺陷分割,分割后计算缺陷面积、边缘灰度均值、内部灰度均值和长宽比等特征表达缺陷信息;在纹理识别方面,提出了基于Contourlet变换的纹理特征提取方法,通过对纹理图像进行Contourlet变换3层分解,得到1个低频子带、6个中频子带和8个高频子带,分别计算低频和中频系数矩阵的均值和方差,并与高频系数矩阵的能量组成22个特征表达纹理信息;最后设计SVM分类器,分别对颜色、缺陷和纹理进行识别。采用300个柞木样本进行实验,板材传送速度在小于1.5 m/s范围内,颜色识别准确率为100%;活节、死结和裂纹识别准确率分别为92.2%、95.6%和93.3%;直纹、弯纹识别准确率分别为93.9%、92.8%。实验结果表明,分选系统具有实时、高效、准确的特点。      

Field performance in agricultural settings of a wireless temperature monitoring system based on a low-cost infrared sensor

Continuous measurement of plant canopy temperature is useful in both research and production agriculture settings. Industrial-quality infrared thermometers which are often used for measurement of canopy temperatures, while reliable, are not always cost effective. For this study a relatively low-cost, consumer-quality infrared thermometer was incorporated into a wireless monitoring system intended for use in plant physiological studies and in agricultural production settings. The field performance of this low-cost wireless system was compared to that of a typical research system based on an industrial-quality infrared thermometer. Performance was evaluated in terms of: reliability of data acquisition, quality of seasonal temperature measurements, seasonal stability of the consumer-quality infrared sensor, and the equivalence of temperatures measured by the consumer-quality and industrial-quality temperature sensors. Results indicate that for many common uses of plant temperature data, the two sensors provide functionally equivalent results. The cost savings and ease of use associated with the low-cost wireless temperature monitoring system present advantages over the higher-cost industrial-quality sensors which may make them a viable alternative in many agricultural settings.     

基于光电传感器的精密播种机排种性能监测系统的研究

【目的】针对玉米、大豆等作物单粒精密播种过程中出现的漏播、重播以及播种量不精准的问题,设计一种基于光电法的单粒精密播种机排种性能监测系统。【方法】采用红外检测装置获取种子下落时的脉冲信号,脉冲信号经单片机处理后统计种子下落时间间隔,并与设定理论时间间隔相比较,计算漏播率、重播率及播种量。以垂直勺轮式排种器为对象,对监测系统进行单粒漏播、重播及播种量监测试验。【结果】该监测系统的单粒监测精度达到98.8%;与排种器性能检测试验台架检测结果相比,监测系统的漏播率监测误差小于0.3%,重播率监测误差小于0.6%;播种量监测精度大于94.4%。【结论】此监测系统工作稳定,监测精度较高。     

Development of a real-time computer vision system for tracking loose-housed pigs

Changes in regulations for livestock animals will in the near future call for loose-house pig breeding systems. These new systems will increase the workload for the farmers, as location and identification of animals will require more time than before. This paper presents a real-time computer vision system for tracking of pigs in loose-housed stables. The system will ease the workload for farmers in identification and locating individual animals. The system consists of a camera and a PC. The PC runs a tracking-algorithm, estimating the positions and identities of the pigs. The tracking algorithm operates in 2 steps. The first step builds up support maps, pointing to preliminary pig segments in each video frame. In the second step the support map segments are used to build up a 5D-Gaussian model of the individual pigs (i.e. position and shape). The system has software correction for fisheye distortion coming from the camera lens. The fisheye lens allows the camera to monitor a much larger area in the stable. The algorithms are developed in MatLab, implemented in C and runs in real-time. Experiments in the lab and in the stable demonstrate the robustness of the system. The system can track at least 3 pigs over a longer time span (more than 8 min) without loosing track and identity of the individual pigs in a realistic experiment.     

RoboCup小型组足球机器人视觉系统的设计

在分析传统视觉系统的基础上,设计了一种新的图像采样处理系统。本系统包括CCD摄像头、SAA7111A、EPF10K10LC84-3、AL422B及TMS320VC5402。实践证明,本系统可明显提高足球机器人视觉系统的速度。     

拖拉机检测线移动平台液压升降系统的设计

阐述了拖拉机移动检测线平台液压举升系统和平台结构方面的设计.针对液压举升系统的不足,平台在升降过程中的不平稳性、振动性,提出了一种液压同步回路设计方案.并通过液压元件的适当选用,大大提高了流量的均匀性和速度的稳定性.实际应用表明,能满足使用需要.     

基于星基增强精密单点定位的农机自动导航系统开发与测试

目的 开发基于星基增强精密单点定位的农机自动导航系统。方法 以国产雷沃TX1204拖拉机为平台,采用国产星基增强定位板卡的输出数据作为农机位置反馈量,设计位速卡尔曼滤波器对定位数据进行滤波处理,开发预瞄跟随PID路径跟踪控制算法进行导航控制,整定不同行驶速度条件下的模型控制参数,采用地基增强RTK高精度定位接收机输出数据作为参考量,搭建农机自动导航测试系统并开展系统性能测试。结果 在直线跟踪误差方面,所开发的农机自动导航系统平均误差为?0.0009436 m,标准差为0.02452 m,最大误差绝对值为0.08472 m;在邻接行误差方面,平均误差为0.0007128 m,标准差为0.02986 m,最大误差绝对值为0.15444 m。这一精度可满足大部分农机自动导航作业需求。结论 将国产星基增强精密单点定位技术用于农机自动导航是可行的;本文设计的预瞄跟随PID路径跟踪控制模型和提出的不同速度条件下PID参数与前视距离的整定方法,提高了系统对不同速度的自适应能力。     

植保机械用容积式泵工作性能测试系统方案设计

植保机械用容积式泵主要用于经济林木和大田作物的药物喷洒,也可用于日常清洗及卫生消毒等领域。基于行业发展和检测能力提升的要求,研制具备较高自动化和智能化水平的工作性能测试系统已成为必然。容积式泵工作性能指标包括容积效率和总效率,是设计测试系统的依据和目的。测试系统主要设计内容包括具备空间多自由度的通用安装平台、高精度的质量法流量计量装置及采用传感器和计算机技术的控制系统,并给出测试系统中工作性能和拟合曲线数学模型。     

冷藏保温汽车静态降温调温性能测试系统的研究

研究并设计出冷藏保温汽车静态降温调温性能自动测试系统,该系统运用单片机ＡＴ８９Ｃ５１、温度传感器保温器及模数转换器等,通过软硬件的配合,实现了多路温度信号的实时采集,用异步串行通信发送数字信号到ＰＣ机,ＰＣ机经过数据的标度转换、分析、整理、分别用棒状图和网状表格显示各路温度瞬时值和平均值,打印出静态降温调温曲线图,该系统自动化程度高,为生产企业产品质量提高提供了一种现代化的测试手段。     

Evaluation of ultrasonic sensor for variable-rate spray applications

Automatic variable-rate sprayers require accurate measurement of canopy size. An estimate of canopy size is made by measuring the distance to the canopy at several elevations above the ground; an ultrasonic sensor was used to determine canopy distance in this study. It is sometimes necessary to conduct spray operations during harsh operating conditions. In this study ultrasonic sensors were subjected to simulated environmental and operating conditions to determine their durability and accuracy. Conditions tested included exposure to extended cold, outdoor temperatures, cross winds, temperature change, dust clouds, travel speeds and spray cloud effects. The root mean square (RMS) error in a series of measurements of the distance to a simulated plant canopy was used to test for significant difference among treatments. After exposure to outdoor cold conditions for 4 months, the RMS error in distance measured by the ultrasonic sensor increased from 3.31 to 3.55 cm, which was not statistically significant. Neither the presence of dust cloud nor the changes in cross-wind speeds over a range from 1.5-7.5 m/s had significant effects on the mean RMS errors. Varying sensor travel speed from 0.8 to 3.0 m/s had no significant influence on sensor detection distances. Increasing ambient temperature from 16.7 to 41.6 °C reduced the detection distance by 5.0 cm. The physical location of the spray nozzle with respect to the ultrasonic sensor had a significant effect on mean RMS errors. The mean RMS errors of sensor distance measurements ranged from 2.3 to 83.0 cm. The RMS errors could be reduced to acceptable values by proper controlling the sensor/spray nozzles spacing on a sprayer. In addition, multiple-synchronized sensors were tested for their measurement stability and accuracy (due to possible cross-talk errors) when mounted on a prototype sprayer. It was found that isolating the pathway of the ultrasonic wave of each sensor reduced detecting interference between sensors during multiple sensor operation. Test methods presented herein may be useful in the design of standardized testing protocols for field use distance sensors.     

计算机应用基础考试系统的设计

为了适应计算机课程的特点,更加准确地测试学生计算机实际操作能力,我们开发了计算机应用基础考试系统。该系统提供了开放式的考试环境,可以测试学生在Windows环境下计算机操作能力和各种应用软件使用能力。