精密播种之电子驱动系统设计

本文研究的排种自动控制系统是依据前轮转速控制排种,在排种量、粒距和前轮转速之间建立关系,并以单片机为核心,配以测速装置、驱动装置及处理电路,输出合理驱动脉冲驱动步进电机的转动,进而带动排种器轴转动达到均匀排种目的的一种电子驱动系统方案.     

THE DEVELOPMENT OF ON-LINE AUTOMATIC MEASURING EQUIPMENTS OF INCREMENTAL LINEAR SENSORS

The auto-measurement of incremental linear transducer by a micro-computer is described and the data of the incremental linear transducer are gained by a computer. Under the control of the computer programme, the on-line datum processing is done and the power spectrum of the data is analyzed by the computer. Thus the auto-measurement of the incremental linear transducer is realized.     

棉籽制油蒸炒工艺的自动控制与研究

介绍一种棉籽制油自动控制系统以及用于制油工艺中的检测和控制方法。在加工过程中，它可以自动调节给水量和蒸炒温度这两个重要参数，使棉籽饼内的残油率有明显降低，同时节能效果也很显著。     

Variable-rate fungicide spraying in cereals using a plant cover sensor

Real-time technology was developed and tested to variably apply fungicides on the plant surface of cereals. An important step towards variable-rate fungicide application in real time is the development and operation of online sensors for measuring plant parameters. The sensor signal of the CROP-Meter (real-time sensor to measure crop biomass density) is correlated with the Leaf Area Index, a measurement characterising the plant surface. Geostatistical analysis of the sensor values in the experimental fields showed that the autocorrelation distance was greater than 25 m, which was wider than the spray boom of the sensor-controlled field sprayer. Control of individual sections of the spray boom was therefore not necessary in the 5-year experiments. In the eleven field trials, average fungicide savings of 22% were achieved. Field scale strip trials were conducted with the sensor-operated field sprayer to analyse the yield response of the crop. Higher, lower, as well as similar yield levels were obtained in the variable-rate plots by comparison with the uniform plots.     

谷物脱粒与分离装置试验数据采集系统

设计了基于计算机测试技术的谷物脱粒与分离试验数据采集系统,分析了系统的传感、测量原理及系统的软硬件功能特点。应用结果表明,该系统工作可靠、测试精度高,可为谷物脱粒与分离试验提供可靠的试验数据。     

The effect of sensor errors on production and energy consumption in greenhouse horticulture

The accuracy of sensors used in Dutch greenhouses for climate control has been assessed and the influence of sensor errors on the energy consumption and crop production has been determined using model simulations. It is shown that currently used sensors are prone to errors exceeding current standards set for practice. The extra energy consumption, due to sensor inaccuracy, is mainly caused by the sensors for global radiation and relative humidity. Sensor errors may result in a higher crop production but at the expense of a higher energy consumption resulting in a loss in economic return of the crop production process. Results indicate that sensor maintenance is economically feasible because the resulting energy savings exceed the costs of the maintenance operation.     

DRIS diagnoses of soybean nitrogen,phosphorus, and potassium status are unsatisfactory

Previous research has shown that the Diagnosis and Recommendation Integrated System (DRIS) is useful to identify the nutrient most likely to limit yield of soybean (Glycine max). However, recent work with other crops has shown that DRIS diagnoses are sometimes unsatisfactory due to large numbers of false positve (F+) diagnoses, which would lead to recommendation of unnecessary fertilizer application. This paper reports a reconsideration using the prescient diagnostic analysis approach of data previously used to establish the diagnostic utility of DRIS for soybean. In addition to previously‐published evaluation criteria, the approach is extended by defining an efficiency rating which accounts for differences in the incidence of sufficient and deficient cases. Using this evaluation approach, DRIS phosphorus (P) and potassium (K) diagnoses of soybean using numerous sources of norms and methods to calculate function values and nutrient indices led to unacceptable efficiency ratings (<67%), even though accuracies often exceeded 90%. In one test, diagnoses of nitrogen (N), P, and K by both DRIS and sufficiency ranges were low in accuracy and efficiency ratings. In several other tests, poor ratings for P diagnoses often followed from low accuracy among deficient cases; i.e. false negative (F‐) diagnoses were excessive. In contrast, K diagnoses were often poor due to low accuracy among cases of sufficiency: false positive (F+) diagnoses were excessive. Despite much modification, DRIS diagnoses of soybean N, P, and K status among data sets of known response to fertilizer application are not sufficiently reliable to support routine adoption of DRIS for diagnosis.     

Introduction of electronics into milking technology

In countries, like the former German Democratic Republic (GDR), where ‘industrialized’ milk production in large herds was the goal to be reached, research on automation of machine milking was started more than 30 years ago. Initially, the main goal was to mechanize operations at the end of the milking process. This work finally resulted in milking devices that do not apply uniform parameters to all cows, but operate according to the milk flow obtained from the cow actually to be milked. This evolution towards ‘controlled milking’ would not have been possible without application of electricity and electronic components for sensors and control units. Also depending on the technical evolution of electronic control systems are devices for recording milk yield and for taking samples for milk analysis, which were available around the year 1980. At that time initial projects for automatic milk recording were evaluated, which had an obvious influence on further development of milk meters. The most demanding step of application of electronic control systems up to now was the introduction of automatic milking systems. Here not only application of teat cups has to be executed, it also is necessary to enable automatic checks of udder condition, milk quality and other operations which may be challenging even for trained human operators. Further evolution of electronic measurement procedures may be important for the milk-producing farmer too, especially when on-line milk analysis is to be introduced within the near future.     

冷链物流车辆监控终端的设计

冷链物流车辆的监控是冷链物流的关键环节,目前我国市面上还没有一款对冷链车辆各方面实时监控的实用监控终端.该研究设计了一款冷链车辆监控终端以实现冷链物流车辆全方位实时监控功能.该终端设备类似于飞机上的“黑匣子”,通过各传感器和摄像头收集冷冻车所在位置、车厢温度、油箱油量、车门状态等重要数据,经过系统分析处理,给相关人员展示当前状态或发出警报以便及时处理,同时保留原始数据以便进行问题追溯.     

Potential use of ground‐based sensor technologies for weed detection

Site‐specific weed management is the part of precision agriculture (PA) that tries to effectively control weed infestations with the least economical and environmental burdens. This can be achieved with the aid of ground‐based or near‐range sensors in combination with decision rules and precise application technologies. Near‐range sensor technologies, developed for mounting on a vehicle, have been emerging for PA applications during the last three decades. These technologies focus on identifying plants and measuring their physiological status with the aid of their spectral and morphological characteristics. Cameras, spectrometers, fluorometers and distance sensors are the most prominent sensors for PA applications. The objective of this article is to describe‐ground based sensors that have the potential to be used for weed detection and measurement of weed infestation level. An overview of current sensor systems is presented, describing their concepts, results that have been achieved, already utilized commercial systems and problems that persist. A perspective for the development of these sensors is given. © 2013 Society of Chemical Industry