基于STC单片机的手推式轨检车主控系统设计

手推式轨检车系统以STC单片机作为控制器核心,采用高性能倾角传感器和直线位移传感器检测铁轨的轨距、水平和里程等参数,并配以键盘和显示电路,与上位机之间采用USB接口方式传输数据。系统实现了数据采集、数据处理、数据存储和数据传输等功能,该设计满足实时性要求,具有快捷、精度高、低功耗、存储容量大、性价比高等优点。     

智能农田作业车辆实时数据采集系统设计试验

为了电路监控、在线诊断、记录机器工作状态及远程调试等要求,智能控制作业车辆农田作业时需要一个可靠的实时数据采集与传输系统.以水田激光平地机为平台,在原系统控制功能基础上设计基于Wi-Fi与SD卡的实时数据采集系统.实时数据一方面将通过Wi-Fi发送供外部接收端无线接收,另一方面将保存在SD卡中,作为Wi-Fi模块的辅助工具.介绍了设计方案与实现过程.为验证本系统可靠性,在实际的水田环境中对此实时数据采集系统进行测试,结果表明此实时数据采集系统能稳定且准确地记录平地机的工作数据,同时,无线Wi-Fi模块在空旷的水田环境中,数据可靠传输距离可达到100 m左右.     

基于MATLAB的实时数据采集与分析系统的实现

用数据采集卡构建的数据采集系统,一般价格昂贵且难以与实际需求完全匹配。为此,提出了一种新的简单可行的方案,利用计算机本身的软硬件资源,不需添加其他任何设备即可构成数据采集与分析系统。详细介绍了该系统的设计方法,使用 MATLAB 语言编制了简洁的图形用户界面,该界面操作方便,并且可以根据用户的需求进行功能扩充。最后给出了详细的试验结果。     

超声数据采集系统设计

本文涉及水下微地形超声探测仪的研发，主要探讨超声探测仪核心系统-超声数据采集系统的设计。首先确定该数据采集系统的基本结构，然后依据探测精度要求对数据采集卡进行选型，最后完成基于PCI-1714高速数据采集卡的超声数据采集软件系统设计，成功开发超声数据采集系统。     

Time series analysis of soybean response to varying atmospheric conditions for precision agriculture

Four time-lapse cameras, Bushnell Nature View HD Camera (Bushnell, Overland Park, KS, USA) were installed in a soybean field to track the response of soybean plants to changing weather conditions. The purpose was to confirm if visible spectroscopy can provide useful data for tracking the condition of crops and, if so, whether game and trail time-lapse cameras can serve as reliable crop sensing and monitoring devices. Using the installed cameras, images were taken at 30-min intervals between July 22 and August 1, 2015. Using the RGBExcel software application developed in-house, image data from the R (red), G (green), and B (blue) bands were exported to Microsoft Excel for further processing and analysis. Daytime adjusted green red index data for the plant, based on the R and G data, were plotted against time of image acquisition and also regressed with selected weather parameters. The former showed a rise-and-fall trend with daily peaks around 13:00, while the latter showed a decreasing order of correlation with weather variables as follows: log of solar radiation?>?log of soil surface temperature?>?log of air temperature?>?log of soil temperature at 50-mm depth?>?log of relative humidity. Despite some low correlations, the potential for using game and trail cameras with time-lapse capability to track changes in crop vegetation response under varying conditions is established. The resulting data can be used to develop models that can aid precision agriculture applications. This can be further explored in future studies.     

基于labVIEW的称重式水果分选机测控系统

为了实现水果的自动分选,设计开发了基于labVIEW的称重式水果分选机。分选机由机械本体、PC计算机、数据采集卡、电动机驱动系统和压力传感器组成,实现了水果的全自动分级。软件以虚拟仪器技术为核心,设计了人性化的人机交互界面。运行试验表明,该系统实时性强,可靠性高,具有良好的应用前景。     

Bistatic scatterometer monitoring of soil moisture by microwave remote sensing at X-band

Soil moisture is important for irrigation planning, as well as in forecast the risk of flash floods, or the occurrence of fog. Measurement of scattering coefficient σ0 of a bare soil was performed by changing the soil moisture content by using the X-band (9.5 GHz) scatter meter. These experiments were conducted over a range of incidence angle from 20° to 70° at step of 5° for both the vertical–vertical (VV) and horizontal–horizontal (HH) polarization. The emissivity is observed by measuring the reflectivity from the microwave system. Results show a good angular variation of emissitivity in both the polarization with soil moisture. An idea was developed by using incidence angles as a modulating factor for retrieving the soil moisture at X-band.     

基于Lab VIEW的麦芽干燥温度控制系统设计

以NI公司的USB-6009数据采集卡为硬件,以Lab VIEW8．5及其PID工具包为软件开发平台,设计一个可实时控制的温度调节系统。该系统通过数据采集卡对现场的温度进行实时采集,并由软件开发平台进行信号的分析处理和显示,然后使用PID神经网络控制算法对现场温度进行实时控制。最后用Matlab仿真软件对干燥系统进行仿真。     

基于CAN总线的汽车车身电器网络实验台的设计

针对网络技术在国内汽车车身尚无应用的现状,提出了一种基于CAN总线的分布式汽车车身网络系统的建立方法,并将其应用于桑塔纳2000型轿车车身电器实验台上。将车身电器按区域划分为9个部分,通过CAN智能节点连接到总线上。对总线参数进行设置,包括节点ID、位定时、位同步、信道延迟等,使得各节点能够有效进行通信。选用89S51单片机和SJA1000CAN控制器设计CAN智能节点。试验室测试时采用PCI-5121智能CAN接口卡将上位机连入总线系统中,分别以单帧和多帧2种方式进行通讯,普通双绞线为通信介质,通讯时间24 h,节点传输速率为40 kbit/s,通讯成功率100%。系统能够实现节点间的可靠通信,达到预期的设计目标。     

农产品薄层干燥实验微机控制及数据采集系统

采用高性能数据采集卡、Ｄ／Ａ转换卡、小信号放大板、数字量Ｉ／Ｏ卡、温湿度传感器和精密重量传感器等与微型电子计算机组成农产品薄层干燥实验过程的控制及数据采集系统．通过盐胚李的薄层干燥实验,表明该系统控制精度高、工作可靠,实现了薄层干燥实验自动化．     

A low-cost microcontroller-based system to monitor crop temperature and water status

A prototype system was developed and constructed for automating the measurement and recording of canopy-, soil-, and air temperature, and soil moisture status in cropped fields. The system consists of a microcontroller-based circuit with solid-state components for handling clock/calendar, sensor power, and data storage and retrieval functions. Sensors, including an analog soil moisture sensor, analog and digital temperature sensors, and a digital infrared thermometer, are widely available and inexpensive. The circuit board and sensor assemblies require approximately 4 h to construct and test, and material costs totaled approximately US$84. Systems were built and tested during the 2009 growing season in a corn field to evaluate performance and suitability under local conditions. The sensors performed according to manufacturers’ specifications, with accuracies of ±0.4 °C, ±1.4 °C, and ±0.3 °C for air-, soil-, and canopy-temperature measurements, respectively. Soil moisture sensors were calibrated and provided measurements within ±2 kPa of the manufacturer's values. Reliability of data collection and storage averaged 91%, with most bad or missing data occurring during periods of inclement weather and electrostatic interference.     

Parameter estimation and validation of a tractor and single axle towed implement dynamic system model

Developing models and estimating model parameters for a tractor and implement system is important for rapid development and improvement of precision implement guidance systems. A dynamic model for a tractor with a towed implement was developed. This model contained a tire lateral force model with several parameters that are varying and difficult to measure accurately. Several field experiments were conducted to collect trajectory data for a tractor with a single axle grain cart. Data from these experiments were used to estimate the tire lateral force model parameters. Three different replicates of the experimental trajectories were collected with each of the step, random and chirp steering inputs. The data was collected at 4.5 m/s forward velocity in two different fields. A two-step optimization process was used to estimate the tire model parameters. First, the experimental data and a set of steady state model equations were used to estimate cornering stiffness parameters. Second, a prediction error minimization method and a dynamic model were used to estimate relaxation length parameters. The parameter estimation process was repeated with each replicate of the experimental data, and the individual estimates were combined using a weighted averaging method. The vehicle model responses with estimated parameters represented the system responses with reasonable accuracy. With the parameters estimated from three different trajectories, the RMSEs for trajectories of tractor and implement CGs varied from 0.05 to 0.83 m. The model-based frequency responses also closely matched with the experimental frequency responses.     

电阻式土壤含水率非扰动连续测量装置的研究

介绍了一种电阻式土壤含水率非扰动连续测量装置;阐述了电阻式土壤水分传感器的结构与工作原理;分析推导了传感器电阻、土壤水势及土壤含水率之间的关系;同时介绍了测量装置的接口电路、单片机数据采集、处理、计算与控制系统的硬件结构及应用程序框图。试验表明,该装置测量速度快、测量精度高,具有显示直观、操作方便、便于携带、适用范围广的优点。     

Different sensing techniques for geomorphometric measurements

Solid-state MEMS accelerometers are small and cost-effective new sensors developed within the last decade that have often been used as tilt sensors in non-agricultural environments. In some applications accelerometers can replace electronic clinometers, which are heavily dampened sensors used in common tilt measurements. Our research tested the hypothesis that either sensor can be used as dynamic tilt sensors and accurately map areas with varying topography. Slope is a vector measurement of the rate of change of elevation, and is a soil attribute commonly studied in the geosciences due to the influence it exerts over other soil attributes and crop yield.Mathematical models were used to relate pitch and roll angles of a roving vehicle to field slope gradient and aspect, based on data collected with a dual-axis accelerometer and a dual-axis clinometer in a field test. Benchmark for comparisons were slope values derived from RTK-GPS measurements. Time-domain and spatial-domain filters were applied to the data collected in the field.The coefficient of determination (r²), mean absolute error (MAE), and model efficiency (ME) were used to compare slope gradient results. Slope aspect was evaluated on whether it was correctly classified according to cardinal directions. Results suggest that the accelerometer and the clinometer are accurate enough to be used as dynamic tilt sensors. The MAEs of slope gradient were less than 1° when compared to measurements derived from RTK-GPS, for scales similar to Order I soil maps. The correct classification of slope aspect was higher than 70%. Solid-state MEMS accelerometers represent a new and cost-effective technology that can be successfully used in such measurements. Accelerometers outperform clinometers in cost, speed, and simplicity of use, but not in accuracy.     

VA菌根菌丝-土壤界面(菌丝际)养分分布模拟方法研究

提出了菌丝-土壤界面(菌丝际)新概念,创立了定量测定菌丝际微域土壤养分分布的盆栽模拟新方法,并以磷为例说明了菌丝吸收对菌丝周围养分变化的影响。     

基于CAN总线的整车管理系统硬件设计

CAN总线是一种有效支持分布式控制和实时控制的串行通讯网络，目前已经在国外汽车的电器网络中得到了广泛的应用。提出了一种基于CAN总线的整车管理系统的硬件设计方案，重点对系统的总体结构、车身控制系统CAN总线的节点设置、节点及中央控制与CAN总线的接口电路进行了设计。     

农业物料力学试验系统研究

研制了农业物料力学试验装置及其测控系统.该系统可用于农业物料力-变形、蠕变及松弛试验.由位移、力等传感器、数据采集卡、开关量输入输出卡和计算机组成试验过程控制及数据采集系统.应用结果表明该系统工作可靠,操作简便,实现了数据采集及试验过程的控制自动化.     

采用单片机技术改进DDL-Ⅲ绘图系统

为了延长进口设备的使用年限,获得最佳经济效益,急需用新型绘图仪改造原DDL-Ⅲ系统的CRT绘图仪。根据IEEE-488总线及GPIB接口卡的功能特点,在对DDL-Ⅲ绘图数据采集及数据格式进行分析的基础上,阐述了用Printrex820绘图仪改造原有CRT绘图仪的智能接口卡的软硬件设计过程。     

基于函数链神经网络的车用发动机气缸压力数据采集系统

为了提高车用发动机运行过程经济性,利用函数链神经网络对曲轴转角值所对应的气缸压力数据进行了拟合,得到了基于函数链神经网络的车用发动机气缸压力数据采集系统.应用结果表明,该气缸压力数据采集系统能有效地消除采集数据时各种干扰的存在,使得采集到的数据偏离其真实数值的程度较小.这对于改善车用发动机的燃烧状况,提高经济性能具有重要的意义.     

基于深度强化学习的耕作层土壤水分、温度预测

【目的】利用土壤近表面空气温湿度与土壤内部参数的关联关系对耕作层土壤水分、温度进行精准预测,为实现精细化农业种植管理提供服务。【方法】针对土壤耕作层水分、温度预测在训练集获取与模型验证等方面的实际需求,设计了基于嵌入式系统及窄带物联网(Narrow band internet of things,NB-IoT)无线通信技术的物联网数据采集系统。在此基础上基于深度Q学习(Deep Q network,DQN)算法探索了一种模型组合策略,以长短期记忆(Long short-term memory,LSTM)、门限循环单元(Gated recurrent unit,GRU)与双向长短期记忆网络(Bidirectional long short-term memory,Bi-LSTM)为基础模型进行加权组合,获得了DQN-L-G-B组合预测模型。【结果】数据采集系统实现了对等间隔时间序列环境数据的长时间稳定可靠采集,可以为基于深度学习的土壤水分、温度时间序列预测工作提供准确的训练集与验证集数据。相对于LSTM、Bi-LSTM、GRU、L-G-B等模型,DQN-L-G-B组合模型在2种土壤类型(...