Farmers' Attitudes to the Benefits and Barriers of Adopting Automation for Surface Irrigation on Dairy Farms in Australia

The study reports farmers' attitudes andperceptions towards the ``barriers' and ``benefits' of automaticirrigation systems. Factor analysis was used to identify perceived ``barriers' and ``benefits' andthe impact of these on farmers' priority to adopt automation wasexamined. Results suggest that farmers'attitudes, particularly with respect to ``cost' and``lifestyle' influenced the priority given to adopting automaticirrigation systems. The area under pasturecultivation was also an importantdeterminant in the farmers' priority foradopting automatic irrigation systems.     

基于PIC16F877的蔬菜大棚自动控制系统研究

为了实现蔬菜大棚的测量、控制以及管理的自动化和科学化,采用PIC16F877作为主控制器,设计了一种蔬菜大棚自动控制系统.为此,介绍了自动控制系统的功能、结构框图,并阐述了其硬件和软件的设计与实现.实验证明,本系统能够对蔬菜大棚内的温度、空气湿度、土壤湿度和光照度等环境因素进行监测与控制,且具有结构简单、成本低和可靠性高等诸多优点,具有很好的推广及应用前景.     

基于道路自动识别ABS模糊控制系统的研究

道路状况自动识别是保证车辆防抱制动系统（ABS）正常工作的前提，本文提根据制动压力，滑移率和车轮减速度进行道路自动识别的方法，并依此设计了ABS模糊控制器，结合7自由度车辆模型，考虑悬架和轮胎的非线性影响，对单一附着系数路变附着系数路面进行了ABS制动模拟试验，试验结果表明，基于路面自动识别ABS模糊控制系统能准确判断出路面状况的变化，据此调整控制策略，使车辆获得最大地面制动力和较好的横向稳定性，对比试验证明它优于传统PID控制，且具有较强的鲁棒性。     

汽车弯道自动转向照明系统的研究

汽车上安装的普通前照灯具有固定的照射范围,当汽车夜间转弯时,由于无法调节照明角度,常在弯道内侧出现"盲区",极大地威胁了驾驶员夜间的驾车安全。本文研究的汽车自动弯道照明系统,安装在货车、农用运输车上,根据夜间行驶道路的弯道情况,随时自动调整弯道照明的光束方向,减少弯道内侧出现的盲区,以便及时发现障碍物和行人,从而增强夜间驾驶的安全性。     

嫁接苗盘自动叠放装置研究与设计

为了提高嫁接作业的自动化水平,实现嫁接操作的流水线生产,设计了用于嫁接作业后期对载有嫁接苗的苗盘自动叠放的装置。该装置的机构部分包括由滚筒和线性模组构成的推送平台,以及由链条、链轮、机架构成的升降机构,采用PLC进行系统控制。试验表明,该装置运行稳定可靠,升降定位精度±1.0mm,最长动作周期26s,适用于现阶段蔬菜嫁接生产流水线。     

无土栽培技术的发展状况及趋势

近年来无土栽培以其优质、高产、高品质的特点,深受人们的关注.介绍了国内外无土栽培的发展状况,着重介绍了国内外无土栽培的栽培方式、自动化程度、营养液的调控和管理技术,并分析了国内无土栽培存在的问题及今后的发展方向.     

棉花膜下滴灌监控系统软件的设计

将工业自动化通用组态软件KingView和VB开发软件有机结合起来,设计棉花膜下滴灌智能决策与自动监控系统软件,并以数据库、模型库、知识库和方法库为技术核心,通过田间传感器进行数据实时采集、计算、分析与决策,由控制系统发送决策指令来控制灌溉设备开/闭,以提高灌溉的时效性。     

Automatic Generation of Curvilinear Grid for Finite Difference Method with Many Inner Objects

In this paper the partial differential equation of coordinate transformation is computed by the finite difference formulations and some examples were computed and illustrated in pictures.     

DIGITAL POWER SYSTEM STABILIZER ( DPSS )

A digital power system stabilizer ( DPSS ) and its design method are presented in this paper. The mathematical model of a single machine infinite bus power system is obtained using off-line parameter identifications, and on the base of the identified model the control system is synthesized by generalized minimum variance control principles. Through feedback combination of several signals this control system has double functions of damping low frequency oscillation and automatic voltage regulating. In order to avoid static errors the very effective way is to combine discrete generalized minimum variance control with continuous integral control. Besides the proposed control strategy is very simple in structures and very easy to realize. Simulation results under several cases have shown the correctness and effectiveness of the proposed control strategy.     

Around Body Flow Computation with Vortex-Flow-streamFunction in Boundary Fitted Coordinates

In this paper, partial differential equations of vortex flow-stream function in boundary fitted coordinates and related ADI equations were listed. The flow around a cylinder in quadrilateral area by auto control boundary was computed. The diagram of distribution of speed arrow, constant lines of flow-stream function, vortex, two speed parts and pressure were studied.