智能农机中精准定位的研究与实现

对智能农机自动驾驶或辅助驾驶中定位方式进行改进,采用GPS/INS组合导航的方式实现精准定位。GPS/INS组合导航能克服仅采用GPS或INS进行定位的缺陷,实现优势互补,减少定位误差。研究了GPS/INS组合导航算法,并对GPS和INS数据采用卡尔曼滤波进行处理,从位置、速度、姿态三方面进行仿真对比分析,验证该算法确实能够减少定位误差,实现较精准的定位。     

Buttock and back pressure distribution tests on seats of mobile agricultural machinery.

Multidisciplinary effort is usually required in the evaluation of comfort problems in the working environment of mobile agricultural machinery workers. Comfort can be partly assessed from the study of the pressure distribution of the human-seat interface. Four combine foam seats and a new air-based seat were compared with regards to static buttocks and back support pressures. Within and between subject variability and the issue of measurement repeatability were addressed. Significant differences were found in the maximum pressure profiles of the four seating systems with seats 2 and 3 performing better than seat I (seat 4 showed no significant difference when compared to the other seats). There is an almost linear relationship between mean pressure and body mass index. In all cases the air seating system performed better with regards to the static pressure gradients.     

农机政务智能客户端系统研究与实现

为适应行业改革过程中对信息系统需求变化,针对目前政务信息系统基本结构,结合B/S和C/S的优劣,提出了以智能客户端技术为主体,采用工作流、基于角色访问控制,系统安全等技术相结合的敏捷系统框架.以四川农机政务系统的建设过程为实践背景,分析了政务系统的基本组成、系统模型,数据服务框架及业务流程定义、解释和执行机制,用角色控制理论构建直线职能型组织结构中各级角色的访问权和操作权分配控制模型及工作流中各业务活动的权限管理,探讨渗透系统全程的安全机制与实现.     

Anthropometric survey for agricultural machinery design: an Indian case study

In Indian agriculture, hand tools, animal-drawn equipment and tractor/power operated machinery are extensively used for various operations. These equipments are either operated or controlled by human workers. Use of anthropometric data can help in the proper design of equipment for better efficiency and more human comfort. Earlier anthropometric surveys carried out in the country were very few and inadequate for use in farm machinery design. Therefore, 52 body dimensions necessary for the design of these equipments were identified and a sample study was conducted on 39 farm workers. The collected anthropometric data were analysed to calculate mean, range, standard deviation and 5th, 50th and 95th percentile values. Through some examples, an effort is made here to illustrate the use of the data in the design of farm equipment. It has now been proposed that extensive surveys should be carried out in different regions of the country to generate the necessary data useful in farm machinery design.     

基于Web的农业机械评标群体决策支持系统研究

结合农业机械投标评价这一复杂问题,给出了在线综合评价群体决策支持系统分析设计的一般思路和方法.采用JSP和J2EE技术实现了集农业机械招标、投标、评标于一体的基于Web的综合评价群体决策支持系统.该系统运用综合评分法、模糊综合评判法、逼近理想解排序法以及基于实例的推理法4种方法进行综合评价,弥补了单一方法的不足,解决了农业机械评标难的问题,提高了决策的科学性.     

资源动态加载算法在农机仿真平台中的实现

在搭建农机仿真平台时,若虚拟农场里的资源过多,使用Unity3D软件默认的一次性加载机制会使载入过程十分缓慢,用户需要漫长的等待时间.针对这个问题,使用资源动态加载算法优化资源的加载过程,使平台更加流畅运行.本文主要阐述了动态加载算法的原理和实现过程.     

The use of pressure mapping to assess the comfort of agricultural machinery seats

Interface pressure measurement gives an objective value to human comfort. Prolonged sitting is known to contribute to musculoskeletal disorders. Driving a tractor involves several actions such as steering, operating levers, buttons, brake and clutch pedals, and looking behind to observe and maneuver the machine. These operations affect sitting posture and create a pattern of loading on the structures of the operator's body.The aim of this study was to study barometric mapping at the operator's buttocks-seat interface for comfort evaluation of the agricultural and forestry machine seats. Three different tractor seats (A “low cost”; B “medium cost”; C “high cost”) were tested during ploughing, harrowing and haying operations, by 8 different operators. Two standardized conditions were used, one on a track with ridges and one on an asphalted surface, with driving tests conducted on both. From each test, the following values were obtained: maximum pressure peak (P_max); average pressure value (P_avg); and the average percentage of cells activated by pressures ranging between 50 and 130 g/cm² (NC_50-130), 131–400 g/cm² (NC_131-400) and higher than 400 g/cm² (NC_401-1000). Mean values of P_avg, P_max, NC_131-400, recorded after the two lab tests (on the road and the ridged track) carried out with seat-A tractors were greater (p < 0.05) than those obtained in tests with more comfortable seats (seats B and C). P_avg and P_max mean values recorded after three field tests carried out with A-seat tractors were greater than those obtained in tests with more comfortable seats (B and C). Similarly, the cell activation in the pressure interval 131–400 g/cm² (NC_131-400) in A-seat tests was significantly greater than that of both B and C seats. Based on our findings, it is possible to conclude that the analyzed pressure indexes in this study are useful instruments to describe the characteristics of seat mapping and compare agricultural machine seats as a function of operator's buttocks-seat interface, thus highlighting the comfort rate obtainable in dynamic situations by the operator.SummaryThe sitting posture is one of the main factors that contribute to musculoskeletal disorders. The methodology is based on barometric mapping for comfort evaluation. Tractors seats were tested in three agriculture operations and on two standardized tracks. The study showed indicators to evaluate barometric maps in dynamics conditions.     

面向Ruby on Rails的多类型RIA集成技术研究

通过对RIA的技术特点进行分析,采用HTTPService和REST风格接口,面向Ruby on Rails模式,设计了一种对多种类型富客户端进行功能调用的集成框架,在可以不断添加新型客户端功能调用的同时简化开发过程、改善用户体验,增强跨平台能力和可降解性.同时支持通用的HTML视图,获得很好的开发效率和效果.     

A generalised learning algorithm based on guard zones

An algorithm for learning class parameters using a restricted updating programme is described along with investigation of its convergence for optimum learning. The algorithm is a generalisation of some existing ones which were found to be useful for practical data.     

产出不确定的农产品供应链协调问题研究

目前关于供应链协调的研究大都基于产出确定的情形,但是现实中却存在很多产出不确定的情形,对此,研究了在产出不确定的背景下农产品供应链的协调问题.首先以期望收益最大化为目标建立数学模型;然后从理论上证明了集中决策下系统存在最优计划生产量,在分散无协调时存在均衡解以及分散有协调情况下风险分担契约能够实现供应链的协调;最后通过实例验证了所提理论的合理性.     

一种基于以太网的防尾随电梯门禁控制系统

针对物联网技术在社区管理中的广泛应用,采用嵌入式技术,利用现代高速发展的网络平台设计了一种基于STM32单片机的电梯门禁控制系统。控制系统在电梯控制系统的基础上,结合门禁控制技术、图像识别技术和RFID技术,实现电梯的联网监控、人员使用管理和防尾随等功能。控制系统采用STM32F407作为主控制芯片,搭载μC/OS-II实时操作系统,通过以太网与路由器连接,实现与智慧社区综合管理平台服务器的通讯。通过测试表明,该系统运行稳定,具有广泛的应用前景。     

Intelligent machinery health prognostics under variable operation conditions with limited and variable-length data

High accuracy health prognostics are significant to machinery intelligent operation and maintenance. Current data-driven prognostics achieve great success that benefits from amply learning samples. In fact, data scarcity challenge widely exists in machinery prognostics and health management, especially for high-end equipment. This study aims to solve this dilemma and proposes a novel meta learning algorithm reconstructed by classic variable-length prediction mode and attention mechanism, namely meta attention recurrent neural network (MARNN). Specifically, we first develop the encoder-decoder with attention mechanism (EDA) cell to perform episodic learning for the subtask-level upgrade. Then multiple subtasks with EDA as prediction models are aggregated to accomplish meta-level upgrade, thus mining the general degradation knowledge from historical datasets. Finally, cross-domain prognostics tasks can be easily realized through fine-tuning tricks, and three rotating machinery run-to-failed experiments are conducted to prove the generalizations of MARNN, which can obtain desired results even when the on-site adaptation data is reduced to one-twentieth.     

基于人体感应的门禁控制系统研究

安全可靠、方便的门禁控制系统与人民生活水平的提高息息相关,近几年门禁控制技术发展迅速。通过对指纹门禁控制系统、人脸门禁控制系统和语音门禁控制系统的深入研究,提出了人体多器官感应的门禁控制系统,提高了门禁控制系统的安全可靠性能。     

基于区块链的智能门禁可信监控系统

为解决传统智能门禁中用户生物特征易被盗取、监控数据易被伪造等问题,提出一种基于以太坊区块链的智能门禁监控系统。利用智能合约将用户身份信息与监控数据写入区块链,配合硬件设计的身份识别与入侵检测,实现链上链下的协同工作,有效避免集中管理造成的数据篡改以及暴力窃取链下用户信息等潜在问题。根据区块链不可篡改的特性,利用代理合约实现智能合约的升级,达到提升系统扩展性的目的。实验结果表明,在保证身份识别以及监控数据可信的基础上,系统性能可以达到实际应用所需效果。     

基于TCP序列号预测的安全分析与防范

TCP/IP协议是按照在开放和彼此信任的群体中使用来设计的,在当前现实环境中却表现出其内在的缺陷。TCP序列号预测成为网络安全领域中最有名的缺陷之一,通过对TCP序列号预测的安全分析及其防范对策,可以尽量减少黑客的入侵,从而保护用户的网络和系统安全。     

基于三线程保护和软件哨兵的防篡改技术

软件哨兵是一种动态防篡改技术,但是哨兵自身安全性无法保障,容易被绕过或移除。针对软件哨兵中存在的安全弊端,着重研究和实现了三线程结构和软件哨兵相结合的动态防篡改技术,利用改进的三线程结构来保护哨兵自身安全。相对于传统的三线程技术,改进后的三线程通过remote线程和watch线程之间的相互监视保护,显著改善了其保护力度,增加了黑客攻击软件哨兵的难度。实验结果表明,采用改进的三线程保护的软件哨兵,不仅能防止软件篡改攻击,还能有效抵抗对哨兵本身的攻击。     

多点警卫现场的智能化集成与分析

数字警卫系统是应对军事突发事件的有效工具,是数据采集、挖掘和智能分析技术的综合应用。这篇文章讨论了构建执行区域警戒的数字警卫框架及其实施的软、硬件环境建设,从低端设备、通信介质、高端设备到决策平台都进行了较为系统的阐述;提出对场点感应数据的整合和挖掘方法,设计了针对军事突发事件的决策支持,提出相应的数据库模型描述的ER图;警卫已经从过去的岗哨演变为智能控制,文章对新技术条件下警卫职能的拓展,提出了自己的见解。