智能可移动道路隔离护栏结构设计【含CAD图纸、说明书】
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毕业设计（论文）中期检查表学院： 机械工程学院 专业： 机械工程 填表日期： 毕业设计（论文）题目： 智能可移动道路隔离护栏结构设计学生姓名： 学号：文献、资料检索阅读：中文 10 篇，外文 5 篇；是否具备独立查阅文献资料的能力 是 。开题完成情况： 好（） 较好（） 一般（） 差（） 未完成（）外文资料翻译情况： 好（） 较好（） 一般（） 差（） 未完成（）学习态度: 好（） 较好（） 一般（） 差（）出勤情况：出勤记载是否详实 是 ；请假次数： 0 ，缺席次数： 0 。毕业设计（论文）的进度（与任务书进度相对照）：正常（） 过快（） 偏慢（）中期检查综合评价：1. 按时完成毕业设计开题报告，具备一定的资料查阅能力； 2. 按时完成英文资料翻译，质量较好； 3. 按进度计划完成毕业设计工作，学习态度认真。存在问题和改进措施：希望进一步加强系统调试方面的技能培养与训练。中期检查结论：好（） 较好（） 一般（） 差（）注：1本表由检查教师填写，交学院保存备查，最终归入学生毕业设计（论文）档案；2本表仅供参考，各学院根据检查需要，可对检查内容进行必要的调整。检查教师： 教研室主任： 毕业设计（论文）任务书题 目: 智能可移动道路隔离护栏结构设计 学生姓名学 院专 业班 级学 号起讫日期指导教师发任务书日期 课题的内容和要求（研究内容、研究目标和解决的关键问题）研究内容：目前越来越多的人选择私家车出行，公共交通设施的发展滞后，城市道路网建设不完善和城市道路规划缺乏前瞻性等原因都直接或者间接导致了城市交通拥堵。潮汐车道是治理交通拥堵的一项重要的措施，潮汐交通流在时间和地域上具有很强的规律性。但潮汐车道如果仅仅依靠道路信号指示，往往造成市民出行看不太明白而走错，甚至引发车祸。由此，设计智能可移动道路护栏，根据潮汐时间的变化自动同步移动。课题主要研究内容包括：智能可移动护栏方案设计；驱动机构设计；护栏及底板结构设计。研究目标： 本课题以学生快速掌握新理论的学习能力为一般培训目标，训练学生面向工程实践需要进行控制系统开发，解决工程实践难题的能力。通过课题研究使学生能了解单片机控制系统的设计过程；学会根据项目要求分析系统需求、制定设计方案、进行机械结构设计。拟解决的关键问题： 机械结构设计及系统联调。课题的研究方法和技术路线通过文献检索和查阅有关的文献资料，了解并掌握智能可移动道路隔离护栏工作的基本原理、基本方法及其应用现状与前景，进行先期理论调研和新理论的补充学习，撰写相关论文。采用理论研究与工程实际相结合的技术路线，在深入了解单片机和潮汐车道等理论知识的基础上，通过工厂参观，实践调研，查阅相关技术文献，进行设计方案论证；采用模块化的设计方法针对智能可移动道路隔离护栏进行具体设计；设计隔离护栏底座小车；进行隔离护栏控制系统及机械系统的整体调试，撰写相关论文。基础条件1具有完整的单片机控制技术资料；2学生通过前期各环节的学习和设计环节的培养已具备机械结构设计的能力；3学生具有掌握新技术和新理念的能力；4指导教师长期从事机电系统的研究，已研制多套机电控制实验台，成功开发过单片机控制系统产品。能在指导过程中通过理论知识的讲授，控制系统开发及机械结构设计的指导，达到完成毕业设计的要求；5产学研合作企业提供良好的现场工作环境可供系统调试。参考文献1 石茂清. 道路交通安全设施设计研究D.西南交通大学,2005.2 孟志广. 交通拥堵及潮汐车道技术的研究D.长安大学,2015.3 徐红领,于泉. 可变车道的国内外研究现状及展望J. 交通标准化,2014,(15):64-67.4 郭继孚,刘莹,余柳. 对中国大城市交通拥堵问题的认识J. 城市交通,2011,(02):8-14+6.5 孟梦,王乾,雷黎. 城市居民出行的潮汐特征研究J. 科技创新导报,2009,(14):203.6 陈筱明. 可移动的交通分隔护栏J. 华东公路,1993,(06):71-72.7 孟杰,孟志广,黄富斌. 潮汐可变车道设置研究J. 市政技术,2015,(06):31-33+37.8 黄诚,王婷静,王永卫. 高等级公路路桥过渡段护栏结构设计J. 华东公路,2008,(01):5-7.9 谢玉洪,雷正保,李海侠. 高速公路防撞护栏的研究现状与发展趋势J. 工程建设与设计,2003(12):40-43.10李萌,张品超,陈婕妤. 动态交通分配下潮汐车道方案设置研究J. 综合运输,2015,(07):78-86.11滕生强 ,高立平. 可变隔离护拦在“潮汐”交通中的应用J. 上海建设科技,2003,(05):18.12宋广全. 高速公路移动护栏的作用和防护装置J. 交通标准化,2003,(04):64-65.13张国华. 关于城市道路潮汐车道的设置研究J. 交通科技,2012,(03):116-119.14 Gui Bin Jia,Zhen Zhou Yuan,Yun Han Li. Design of Traffic Organization Refer to Variable Lanes at the IntersectionJ. Applied Mechanics & Materials, 2013, 409-410:1118-1121.15 Ma Jun. Detailed study of B037 based on HST imagesJ. Research in Astronomy andAstrophysics, 2011, 11(5):524-536.16 Christoph Schwietering,Michael Feldges. Improving Traffic Flow at Long-term Roadworks J. Transportation Research Procedia, 2016, 15:267-282.17 Ma J. Detailed study of BO37 based on HST imagesJ. Research in Astronomy and Astrophysics, 2011, 11(5):524-536.18 Schwietering C,Feldges M. Improving Traffic Flow at Long-term Roadworks J. Transportation Research Procedia, 2016, 15:267-282.本课题必须完成的任务：1了解智能可移动道路隔离护栏工作的基本原理、方法及其发展近况；2根据智能可移动道路隔离护栏必须具备的功能,给出总体设计方案；3构建系统硬件平台；4完成隔离护栏底座小车设计；5撰写毕业设计论文，字数应不少于8000字；6翻译相关英文文献资料。成果形式1毕业设计论文；2机构设计图纸；3英文翻译资料。进度计划起讫日期工作内容备 注3.19-3.25资料收集及翻译资料学生自学及讲授3.26-4.1工厂参观、阅读资料小组讨论4.2-4.8确定总体方案、开题小组讨论4.9-4.22控制系统硬件平台构造个别指导4.22-5.6隔离护栏底部小车及护栏设计个别指导5.7-5.20系统总体调试小组讨论5.21-6.9完成论文撰写，准备答辩小组交流、汇报、图纸审核、论文审核教研室审核意 见 经系审核，课题内容和要求明确，难度和工作量大小适中，计划合理，同意下发。教研室主任签名： 2018 年 3 月 22 日学院意见同意 教学院长签名： 2018 年 3 月 23 日 毕业设计（论文）开题报告学生姓名 学 号 专业机械工程课题名称智能可移动道路隔离护栏结构设计阅读文献情 况国内文献11篇开题日期 国外文献 5篇开题地点12#3031.文献综述与调研报告：（阐述课题研究的现状及发展趋势，本课题研究的意义和价值、参考文献）课题研究的现状及发展趋势: 随着中国城镇化、机动化进程的不断加快，客、货运量和机动车保有量的增加，道路建设和安全管理设施远远满足不了形式的发展1，以交通拥堵为代表的城市交通问题普遍成为困扰各大城市的难题。对于城市交通堵塞来说，城市道路交通系统的局部供需矛盾突出。非交通性占道、道路需求局部过剩以及交通流诱导失常，使整个道路交通系统的负荷不均匀2。因此，近年来我国各个城市的交通拥堵问题已成为制约城市发展、城市交通的主要问题3。各地一方面通过对城市交通进行合理的规划，加大对基础设施的投入，大力发展城市高架桥、地铁等立体交通,另一方面通过对道路的重新分配,开辟某一条或几条车道在不同时段内行驶方向的变化,来增加路面资源的利用率。虽然实施的措施可以改善部分路段的交通堵塞的问题，但是随着人口的不断增加，城市变得更加的拥挤，可利用的城市空间变得越来越少。 不管是国内的北京、上海等一线城市，还是那些伦敦、东京这样的国际都市，交通拥堵都是非常常见的现象。对于大城市来说，针对交通堵塞问题,采用车流调度实现设备化的控制,在交通智能化方面具有非常重要的意义4。所以专家通过研究发现了一种非常有代表性的交通堵塞形式潮汐堵塞。潮汐式拥堵指的是路段拥堵的程度随着时间的变化，每天呈现类似的周期性变化，出现所谓的早高峰和晚高峰拥堵。形成潮汐式拥堵的原因一方面是我国经济发展迅速，城市发展的规模越来越大，市区里的土地价值不断地提高，房价不断上涨，严重超出了市民的极限，而城市小汽车的拥有量越来越多且增长速度越来越快，因此，越来越多的人选择住在郊区但开车上下班的生活模式，所以就出现了早晚高峰期的潮汐式交通堵塞5；另一方面随着城市功能区的划分，极大地改变了原有城市道路的交通流6，特别是一些特定的连接干道，也形成了固定时段的潮汐车流。因此，你会发现道路护栏的一边非常的拥堵，而护栏的另一边却与之形成对比，道路上的车辆却很少。 考虑到大部分城市中心区的建设已经饱和，传统方案几乎不可行，因此解决这一问题的基本途径有两条：第一，重新进行城市规划，分散居住地和工作区域；第二，实行智能交通控制，通过智能可移动道路隔离护栏，形成了道路上可变车道78，并根据车流变化情况快速准确的改变可变车道的通行方向来解决潮汐式交通910。所谓可变车道，指的是结合道路车流量的潮汐性特征，使得路段上车道的通行方向随着车流量的变化而变化11。通过这种方法使得主流量方向的交通拥堵尽快的解决。即能合理使用道路，充分提高道路利用率及道路通行能力，又可以减少交通成本和改变城市规划等优点。但针对这种解决潮汐交通的方式，目前还存在如下问题： 1.可变车道只是用指示灯或者指示牌来提示驾驶员，容易误导驾驶员，使得驾驶员得不到很好的安全保障，容易引发交通事故。 2.早期实验阶段，由于不熟悉潮汐车道，很多驾驶员的车辆会误入潮汐车道，使得交通状况更加恶劣。 3.由于潮汐车道和其他车道仅靠道路标线区分，会有车辆出现超车逆行的危险行为，严重危害到其他驾驶员的生命安全。 本课题研究的意义和价值: 本毕业设计通过对智能可移动道路隔离护栏的结构1213、信息自动化的控制、安全预警机制等智能化的研究，提出对传统的护栏的改造的方案,使护栏行成在各个硬件相互独立控制方面又相互依托的若干板块，在各个板块正常运转的前提下更好的缓解重交通流方向交通压力。 本智能可移动道路隔离护栏是在不占用道路空间、不破坏路面结构的前提下，具有自主实时采集交通量数据、自动判断移动条件、预警等功能的智能化信息化新型可移动护栏1415。 护栏优化设计的创新与特色有以下几个方面： 1.护栏在移动过程中能够做到了尽量不影响次交通流方向的车辆通行，这样充分减少了交通延误。 2.护栏采用分块移动的模式，尽可能的减少对交通环境的影响。 3.智能可移动道路隔离护栏的底座采用的是AGV小车，控制系统上采用的是STM32单片机控制，可以实现让小车前进、后退、旋转，可以根据移动轨迹自动调整前进路线，自动启停等16。 4.护栏动力装置选用步进电机，我们通过计算和模拟护栏动力装置选用合适的步进电机，保证整体稳定性，防止在移动过程中由于护栏的不合理设计而倾倒，不利于系统的正常运作，也影响交通的安全，保证护栏的制造、安装、维修经济合理。 在了解了该方面的许多专业知识后，我选择了这一课题以做研究，希望有所成功。对于该课题的研究有以下几点意义： 智能可移动道路隔离护栏可以最大化的改善交通拥堵的状况，减少交通事故的发生。智能可移动道路隔离护栏可以为社会减少一些不必要的交通投入，可以帮助交警更好更快的改善拥堵。智能可移动道路隔离护栏可以让社会感受到智能化，为今后的信息化、智能化做出了铺垫。 参考文献： 1 文渊,唐志波. 诱发城市交通堵塞的几个关键问题浅析及对策研究J. 管理观察, 2017,(3): 163-167. 2 张博,易振宇. 关于深圳市交通堵塞的问题研究J. 建材与装饰, 2017,(32): 182-183. 3 郭继孚,刘莹,余柳. 对中国大城市交通拥堵问题的认识J. 城市交通, 2011, (02): 8-14. 4 Christoph Schwietering,Michael Feldges. Improving Traffic Flow at Long-term RoadworksJ. Transportation Research Procedia, 2016,15: 267-282. 5 徐红领,于泉. 可变车道的国内外研究现状及展望J. 交通标准化, 2014,(15): 64-67. 6 孟梦,王乾,雷黎. 城市居民出行的潮汐特征研究J. 科技创新导报, 2009,(14): 203. 7 孟杰,孟志广,黄富斌,王涌. 潮汐可变车道设置研究J. 市政术, 2015,(06): 31-33. 8 张国华. 关于城市道路潮汐车道的设置研究J. 交通科技, 2012,(03): 116-119. 9 李萌,张品超,陈婕妤. 动态交通分配下潮汐车道方案设置研究J. 综合运输, 2015,(07): 78-86. 10 孟志广. 交通拥堵及潮汐车道技术的研究D. 长安大学, 2015. 11 Gui Bin Jia,Zhen Zhou Yuan,Yun Han Li. Design of Traffic Organization Refer to Variable Lanes at the IntersectionJ. Applied Mechanics and Materials, 2013,2684(409): 1181-1121. 12 陈筱明. 可移动的交通分隔护栏J. 华东公路, 1993,(06): 71-72. 13 宋广全. 高速公路移动护栏的作用和防护装置J. 交通标准化, 2003,(04): 64-65. 14 Huang HW. Mo JX, Yang JK. Research on correlative factors of the protective performance of W-Beam GuardrailJ. Hunan Univ, 2004, 31(2): 45-47. 15 Hou S,Tan W Zheng Y, Han X, Li Q, Optimization design of corrugated beam guardrail based on RBF-MQ surrogate model and collision safety considerationJ. Adv Eng SOftw, 2014, 78: 28-40. 16 Jun Ma. Detailed study of B037 based on HST imagesJ. Research in Astronomy and Astrophysics, 2011, 11(5): 524-536. 2.本课题的基本内容，预计解决的难题研究内容：随着我国城市交通工具机动化程度不断提高，城市基础交通系统发展滞后，因此，潮汐式交通堵塞成为了困扰各个城市的难题。潮汐式拥堵在时间和地区具有很强的规律。解决潮汐式拥堵的潮汐车道仅靠交通信号灯的变化来指示的话，会使驾驶员驶错车道，造成车祸。因此，设计一款智能可移动道路隔离护栏，可以根据潮汐时间的变化自主移动到潮汐车道。该课程设计内容包括：智能可移动护栏方案设计；护栏和AGV智能小车车底设计；升降机构设计。研究目标：本课题以学生快速掌握新理论的学习能力为一般培训目标，训练学生面向工程实践需要进行控制系统开发，解决工程实践难题的能力。通过课题研究使学生能了解单片机控制系统的设计过程；学会根据项目要求分析系统需求、制定设计方案、进行机械结构设计。 关键问题：机械结构设计及系统联调。 3.课题的研究方法、技术路线研究方法：通过文献检索和查阅有关的文献资料，了解并掌握智能可移动道路隔离护栏工作的基本原理、基本方法及其应用现状与前景，进行先期理论调研和新理论的补充学习，撰写相关论文。 技术路线：采用理论研究与工程实际相结合的技术路线，在深入了解单片机和潮汐车道等理论知识的基础上，通过工厂参观，实践调研，查阅相关技术文献，进行设计方案论证；采用模块化的设计方法针对智能可移动道路隔离护栏进行具体设计；设计隔离护栏底座小车；进行隔离护栏控制系统及机械系统的整体调试，撰写相关论文。 4.研究工作条件和基础1.具有完整的单片机控制技术资料； 2.学生通过前期各环节的学习和设计环节的培养已具备机械结构设计的能力； 3.学生具有掌握新技术和新理念的能力； 4.指导教师长期从事机电系统的研究，已研制多套机电控制实验台，成功开发过单片机控制系统产品。能在指导过程中通过理论知识的讲授，控制系统开发及机械结构设计的指导，达到完成毕业设计的要求； 5.产学研合作企业提供良好的现场工作环境可供系统调试。 五、进度计划起讫日期工作内容3.19-3.25收集资料及翻译资料3.26-4.1工厂参观、阅读资料4.2-4.8确定总体方案4.9-4.22控制系统硬件平台构造4.22-5.6隔离护栏底座小车及护栏设计5.7-5.20系统总体调试5.21-6.9完成论文撰写，准备答辩指导教师评语该生针对本课题查阅相关中英文参考资料16篇（本），对课题的研究现状及发展趋势有了初步了解，确立的研究内容充实，研究方法和技术路线合理可行，具备了一定的知识积累，同意开题。 导师签名： 徐海黎 2018 年 4 月 25 日教研室意见经系审核，该课题工作量适度，难易程度适中，符合专业培养目标和方向。学生对所做课题已理解，在调研基础上提出的方案和计划可行，符合开题条件，准予开题。 教研室主任签名： 2018 年 4 月 26 日学院意见通过开题（ ） 开题不通过（ ） 教学院长签名： 2018 年 4 月 26 日 立题卡课题名称智能可移动道路隔离护栏结构设计 出题人 课题表述（简述课题的背景、目的、意义、主要内容、完成课题的条件、成果形式等）课题背景、目的、意义：目前越来越多的人选择私家车出行，公共交通设施的发展滞后，城市道路网建设不完善和城市道路规划缺乏前瞻性等原因都直接或者间接导致了城市交通拥堵。潮汐车道是治理交通拥堵的一项重要的措施，潮汐交通流在时间和地域上具有很强的规律性。但潮汐车道如果仅仅依靠道路信号指示，往往造成市民出行看不太明白而走错，甚至引发车祸。由此，设计智能可移动道路护栏，根据潮汐时间的变化自动同步移动。 主要研究内容：智能可移动护栏方案设计；四轮独立驱动机构设计；升降机构设计；同步机构设计。 完成课题的条件：学生通过前期各环节的学习已具备控制系统开发的能力；学生具有掌握新技术和新理念的能力；指导教师长期从事机电系统的研究，已研制多套机电控制实验台，成功开发过单片机控制系统产品，能在指导过程中通过理论知识的讲授，硬件设计和程序编制的指导，达到完成毕业设计的要求；产学研合作企业提供良好的现场工作环境可供系统调试。 成果形式：毕业论文、图纸 课题来源社会生产实际课题类别毕业设计该课题对学生的要求要求学生具备较好的机电一体化方面的基础知识。 教研室意见选题符合机械类本科毕业设计要求 教研室主任签名： 2017 年 12 月 7 日学院意见同意立题（） 不同意立题（ ） 教学院长签名： 2017 年 12 月 28 日 Procedia Engineering 149 ( 2016 ) 404 413 1877-7058 2016 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (/licenses/by-nc-nd/4.0/). Peer-review under responsibility of the organizing committee of ICMEM 2016 doi: 10.1016/eng.2016.06.685 ScienceDirect Available online at * Corresponding author. Tel.: +4210455206477 E-mail address: pivarciovatuzvo.sk International Conference on Manufacturing Engineering and Materials, ICMEM 2016, 6-10 June 2016, Nov Smokovec, Slovakia Mobile robot controlling possibilities of inertial navigation system Mohammad Emal Qazizadaa Elena Pivariova* aTechnical University in Zvolen, Faculty of Environmental and Manufacturing Technology, Department of Machinery Control and Automation Technology, Masarykova 24, 960 53 Zvolen, Slovakia Abstract The paper explain analysis of inertial navigation system and accelerometric, gyroscopic sensors and describe possibilities of their application for inertial navigation of mobile robot. Such controlling system allows to monitor exact position of robot. These information can be applied for robot controlling, its autonomous control or its tracking. Inertial navigation is completely autonomous and independent from surroundings, i.e. the system is resistant from external influences as magnetic disturbances, electronically disturbance, signal deformation, etc. For mobile robots to be successful, they have to move safely in environments populated and dynamic. While recent research has led to a variety of localization methods that can track robots well in static environments, we still lack methods that can robustly localize mobile robots in dynamic environments. 2016 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the organizing committee of ICMEM 2016 Keywords: inertial navigation system, robots, gyroscop, accelerometer 1. Introduction Inertial navigation is a self-contained navigation technique in which measurements provided by accelerometers and gyroscopes are used to track the position and orientation of an object relative to a known starting point, orientation and velocity. Inertial measurement units (IMUs) typically contain three orthogonal rate-gyroscopes and three orthogonal accelerometers, measuring angular velocity and linear acceleration respectively. By processing signals from these devices it is possible to track the position and orientation of a device. Inertial navigation is used in a wide range of applications including the navigation of aircraft, tactical and strategic missiles, spacecraft, submarines and ships. Recent advances in the construction of MEMS devices have made it possible to manufacture small and light inertial navigation systems. These advances have widened the range of possible applications to include areas such as human and animal motion capture 1. Inertial navigation systems have been widely used in aerospace applications but have yet to be seriously exploited in robotics applications where they have considerable potential. In the integration of inertial and visual information is investigated. Methods of extracting the motion and orientation of the robotic system from inertial information are derived theoretically but not directly implemented in a real system. Inertial sensors are used to estimate the attitude of a mobile robot. With the classical three-gyro, two-accelerometer configuration, experiments are performed to estimate the roll and pitch of the robot when one wheel climbs onto a plank using a small inclined plane. One reason that inertial systems are widely used in aerospace applications but not in robotics applications is simply that high-quality aerospace inertial systems are comparatively too expensive for the budgets of most robotics systems. However, low-cost solid-state inertial systems, motivated by the needs of the automotive industry, are increasingly being made commercially available. Although a considerable improvement on past systems, they clearly provide substantially less accurate position information than equivalent aerospace systems. 2016 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (/licenses/by-nc-nd/4.0/). Peer-review under responsibility of the organizing committee of ICMEM 2016 405 Mohammad Emal Qazizada and Elena Pivariov / Procedia Engineering 149 ( 2016 ) 404 413 Inertial Navigation Systems (INS) have been developed for a wide range of vehicles. Sukkarieh 2 developed a GPS/ INS system for straddle carriers that load and unload cargo ships in harbors 3. Bennamoun et al 4 developed a GPS/INS/SONAR system for an autonomous submarine. The SONAR added another measurement to help with accuracy, and provided a positional reference when the GPS antenna got submerged and could not receive a signal 3. Ohlmeyer et al 5 developed a GPS/INS system for a new smart munitions, the EX-171. Due to the high speed of the missile, update rates of 1 second from a GPS only solution were too slow, and could not provide the accuracy needed. Jorge Lobo et al 6 describes a prototype of an inertial navigation system for use in mobile land vehicles, such as cars or mobile robots. Dieter Fox et al 7, describes operate autonomously, mobile robots must know where they are. Mobile robot localization, that is the process of determining and tracking the position (location) of a mobile robot relative to its environment, has received considerable attention over the past few years 8. Robot localization has been recognized as one of the most fundamental problems in mobile robotics 9, 10. Pirnk et al 11 uses INS for control of wheel chassis from inertial sensors based on data. Abramov and Boek 12 used INS for application of inertial measurement system in machinery. 2. Inertial Navigation System Inertial navigation uses gyroscopes and accelerometers to measure rate of rotation and acceleration. Measurements are integrated once (or twice, for accelerometers) to yield position. Inertial navigation systems have the advantage that they are self- contained, that is, they dont need external resources. However, inertial sensor data drift with time because of the need to integrate rate data to yield position. Inertial sensors are thus mostly unsuitable for accurate positioning over an extended period of time 13. Self-contained inertial navigation is a navigation technique provided by accelerometers and gyroscopes are used to track the position and orientation of an object relative to a starting point, direction and velocity. An IMU is a “clump“ of six inertial sensors. Three linear accelerometers and three rate gyros make up an IMU. Usually, an IMU also contains a computational unit to do the position calculations based off of the sensors. The operation to combine information from such multi-modal sensors is called sensory fusion 14. An IMU is sufficient to navigate relative to inertial space (no gravitation present), given initial values of velocity, position and attitude: ? Integrating the sensed acceleration will give velocity. ? A second integration gives position. ? To integrate in the correct direction, attitude is needed. This is obtained by integrating the sensed angular velocity. In terrestrial navigation (close to the Earth) we compensate for gravitation, and rotation of the Earth. Equations integrating the gyro and accelerometer measurements into velocity, position and orientation are called navigation equations 15. The combination of an IMU and a computer running navigation equations is called an Inertial Navigation System (INS). Fig. 1: Inertial navigation system 15 2.1. Navigation Equations The principle of inertial navigation laws are managed by classical mechanics, which defined by Newton. Looking at Newtons second law of movement, a change in motion occurs as a force is applied to a body. Now, dividing both sides of the equation by the mass of the object results in the certain force. In inertial navigation, accelerometers detect accelerations due to forces exerted on the body 3. ? ? ? ? ? ?(1) 406 Mohammad Emal Qazizada and Elena Pivariov / Procedia Engineering 149 ( 2016 ) 404 413 Typically these forces as special forces called (S). Thus reading from the IMU will be referred to as specific forces, which are independent of the mass 3. 3. Accelerometer Accelerometers are used to measure acceleration along one or more axis and are relatively insensitive to orthogonal directions. Accelerometer is electromechanical device to measure acceleration forces: ? Static forces like gravity pulling at an object lying at a table ? Dynamic forces caused by motion or vibration Accelerometer Applications: ? Automotive: monitor vehicle tilt, roll, skid, impact, vibration, etc., to deploy safety devices (stability control, anti-lock breaking system, airbags, etc.) and to ensure comfortable ride (active suspension) ? Aerospace: inertial navigation, smart munitions, unmanned vehicles ? Sports/Gaming: monitor athlete performance and injury, joystick, tilt ? Personal electronics: cell phones, digital devices ? Security: motion and vibration detection ? Industrial: machinery health monitoring ? Robotics: self-balancing 3.1. Types of Accelerometer Accelerometer can be broadly classified either a mechanical or solid state device. 3.1.1. Mechanical Accelerometer A mechanical accelerometer include of a mass suspended by springs, as shown in Figure 2. The displacement of the mass is measured using a movement pick-off, giving a signal that is proportional to the force F acting on the mass in the orientation of the input axis. Newtons second law F = ma is then used to calculate the acceleration acting on the device. Fig. 2: Accelerometer structure. Proof mass is attached through springs 16 3.1.2. Solid State Accelerometer Solid state accelerometer can be divided to various subgroups, including surface vocal wave, vibratory, silicon and quartz devices. Solid state accelerometers are small, trustworthy and rough. An example of a solid-state accelerometer is the surface acoustic wave (SAW) accelerometer. A SAW accelerometer consists of a linchpin beam which is resonated at a specific frequency, as shown in Figure 3. A mass is depended to one end of the beam which is free to move. The other end is hardly attached to the case. When an acceleration is applied along the input axis the beam curved. This causes the frequency of the surface acoustic wave to change symmetrically to the applied strain. By measuring this change in frequency the acceleration can be specified. 407 Mohammad Emal Qazizada and Elena Pivariov / Procedia Engineering 149 ( 2016 ) 404 413 Fig. 3: Surface acoustic wave (SAW) 17 3.1.3. MEMS Accelerometers Abbreviation MEMS based on the “microelectromechanical systems“. What means systems in which there are implemented on one chip micromechanical structures forming sensor as such, with controlling and evaluation electronical circuits. Silicon micro-machined accelerometer using the same principles of mechanical and solid state sensors. There are two main category of MEMS accelerometer. The first category consists of mechanical accelerometers (i.e. devices which measure the displacement of a supported mass) manufactured using MEMS techniques. The second class consists of devices which measure the change in frequency of a vibrating element caused by a change of traction, as in SAW accelerometers. They are small, light and contain low power consumption and start-up times. Their basic disadvantage is that they are not currently as accurate as accelerometers manufactured using traditional techniques, although the implement of MEMS devices is improving quickly 1. Typical MEMS accelerometer is composed of movable proof mass with plates that is attached through a mechanical suspension system to a reference frame, as shown in Figure 4. Movable plates and fixed outer plates show capacitors. The deviation of proof mass is measured using the capacitance difference 1. Proof mass is attached through springs (kS: spring constant) at substrate. It can move only up and down. Movable and fixed plates construct capacitors. Fig. 4: Accelerometer structure 18 The free-space (air) capacitances between the movable plate and two stationary outer plates C1 and C2 are functions of the corresponding displacements x1 and x2: ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? If the acceleration is zero, the capacitances C1 and C2 are equal because x1= x2. The proof mass displacement x results due to acceleration. If x 0, the capacitance difference is found to be: 408 Mohammad Emal Qazizada and Elena Pivariov / Procedia Engineering 149 ( 2016 ) 404 413 ? ? ? ? ? ? ? ? Measuring C, one finds the displacement x by solving the nonlinear algebraic equation: ? ? ? ? ? This equation can be simplified. For small displacements, the term Cx2is negligible. Thus, Cx2 can be omitted. Then, from ? ? ? ? ? ? ? ? ? one concludes that the displacement is approximately proportional to the capacitance difference C 18. 3.2. Working principle of typical accelerometer The principle of working of an accelerometer can be explained by a simple mass (m) attached to a spring of stiffness (k) that in turn is attached to a casing, as illustrated in Figure 5. The mass used in accelerometers is often called the seismic-mass or proof-mass. In most cases the system also includes a dashpot to provide a desirable damping effect. The dashpot with damping coefficient (c) is normally attached to the mass in parallel with the spring. When the spring mass system is subjected to linear acceleration, a force equal to mass times acceleration acts on the proof-mass, causing it to deflect. This deflection is sensed by a suitable means and converted into an equivalent electrical signal. Some form of damping is required, otherwise the system would not stabilize quickly under applied acceleration. To derive the motion equation of the system Newtons second law is used, where all real forces acting on the proof-mass are equal to the inertia force on the proof-mass. Accordingly a dynamic problem can be treated as a problem of static equilibrium and the equation of motion can be obtained by direct formulation of the equations of equilibrium. This damped mass-spring system with applied force constitutes a classical second order mechanical system. From the stationary observers point of view, the sum of all forces in the z direction 19. Fig. 5: Schematic of an accelerometer 19 ? ? ? ? ? ? ? where: m mass of the proof-mass, x relative movement of the proof-mass with respect to frame, c damping coefficient, k spring constant, F force applied The equation of motion is a second order linear differential equation with constant coefficients. The general solution X(t) is the sum of the complementary function XC(t) and the particular integral XP(t). ? ? ? ? ? The complementary function satisfies the homogeneous equation. ? ? ? ? ? ? ? The solution to ? (?) is: ? ? ? Substituting (10) in (9) 409 Mohammad Emal Qazizada and Elena Pivariov / Procedia Engineering 149 ( 2016 ) 404 413 ? ? ? ? ? As ? ? cannot be zero for all values of t, then, ? ? ? ? ? ? called as the auxiliary or characteristic equation of the system. The solution to this equation for values of S is: ? ? ? ? ? ? ? ? From the above equation 6, the following useful formulae are derived ? ? ? ? ? ? ? ? ? ? ? ? ? where n undamped resonance frequency, k spring constant, m mass of proof-mass, c damping coefficient, ? damping factor ? ? ? ? ? ? ? ? ? 4. Gyroscopes A gyroscope is a device for measuring or maintaining orientation, based on the principles of conservation of angular momentum. There exist a few basic types of gyroscopes. 4.1. Mechanical gyroscopes A conventional gyroscope contains of a spinning wheel mounted on two gimbals which allow it to rotate in all three axes, as show in Figure 6. An effect of the safekeeping of angular momentum is that the spinning wheel will resist changes in orientation. Thus when a mechanical gyroscope is expose to a rotation the wheel will remain at a constant global orientation and the angles between adjacent gimbals will change. To measure the orientation of the device the angles between adjacent gimbals can be read using angle pick-offs. Note that a conventional gyroscope measures orientation. In contrast nearly all modern gyroscopes (including the optical and MEMS types) are rate-gyros, which measure angular velocity. The main disadvantage of mechanical gyroscopes is that they contain moving parts. Moving parts cause friction, which in turn causes the output to drift over time. To minimize friction high-precision bearings and special lubricants are used, adding to the cost of the device. Me
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