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2024年1月4日发(作者:普拉替尼胶囊就医指征)
中英文翻译-机械类-机械设计-外文翻译
第一篇:中英文翻译-机械类-机械设计-外文翻译
机械设计
摘要: 机器是由机械装置和其它组件组成的。它是一种用来转换或传递能量的装置,例如:发动机、涡轮机、车辆、起重机、印刷机、洗衣机、照相机和摄影机等。许多原则和设计方法不但适用于机器的设计,也适用于非机器的设计。术语中的“机械装置设计” 的含义要比“机械设计”的含义更为广泛一些,机械装置设计包括机械设计。在分析运动及设计结构时,要把产品外型以及以后的保养也要考虑在机械设计中。在机械工程领域中,以及其它工程领域中,所有这些都需要机械设备,比如:开关、凸轮、阀门、船舶以及搅拌机等。关键词: 设计流程 设计规则 机械设计
设计流程
设计开始之前就要想到机器的实际性,现存的机器需要在耐用性、效率、重量、速度,或者成本上得到改善。新的机器必需具有以前机器所能执行的功能。
在设计的初始阶段,应该允许设计人员充分发挥创造性,不要受到任何约束。即使产生了许多不切实际的想法,也会在设计的早期,即在绘制图纸之前被改正掉。只有这样,才不致于阻断创新的思路。通常,还要提出几套设计方案,然后加以比较。很有可能在这个计划最后决定中,使用了某些不在计划之内的一些设想。
一般的当外型特点和组件部分的尺寸特点分析得透彻时,就可以全面的设计和分析。接着还要客观的分析机器性能的优越性,以及它的安全、重量、耐用性,并且竞争力的成本也要考虑在分析结果之内。每一个至关重要的部分要优化它的比例和尺寸,同时也要保持与其它组成部分相协调。
也要选择原材料和处理原材料的方法。通过力学原理来分析和实现这些重要的特性,如那些静态反应的能量和摩擦力的最佳利用,像动力惯性、加速动力和能量;包括弹性材料的强度、应力和刚度等材
料的物理特性,以及流体润滑和驱动器的流体力学。设计的过程是重复和合作的过程,无论是正式或非正式的进行,对设计者来说每个阶段都很重要。
最后,以图样为设计的标准,并建立将来的模型。如果它的测试是符合事先要求的,则再将对初步设计进行某些修改,使它能够在制造成本上有所降低。产品的设计需要不断探索和发展。许多方案必须被研究、试验、完善,然后决定使用还是放弃。虽然每个工程学问题的内容是独特的,但是设计师可以按照类似的步骤来解决问题。
产品的责任诉讼迫使设计人员和公司在选择材料时,采用最好的程序。在材料过程中,五个最常见的问题为:(a)不了解或者不会使用关于材料应用方面的最新最好的信息资料;(b)未能预见和考虑材料的合理用途(如有可能,设计人员还应进一步预测和考虑由于产品使用方法不当造成的后果。在近年来的许多产品责任诉讼案件中,由于错误地使用产品而受到伤害的原告控告生产厂家,并且赢得判决);(c)所使用的材料的数据不全或是有些数据不确定,尤其是当其性能数据长期不更新;(d)质量控制方法不适当和未经验证;(e)由一些完全不称职的人员选择材料。
通过对上述五个问题的分析,可以得出这些问题是没有充分理由而存在的结论。对这些问题的研究分析可以为避免这些问题的出现而指明方向。尽管采用最好的材料选择方法也不能避免发生产品责任诉讼,设计人员和工业界按照适当的程序进行材料选择,可以大大减少诉讼的数量。
从以上的讨论可以看出,选择材料的人们应该对材料的性质,特点和加工方法有一个全面而基本的了解。
在随后生产和售后服务的几年中,要接受新观念的变化,或者由试验和经验为基础,进一步分析并改进。
一些设计规则
在本节中,建议要运用创造性的态度来替代和改进。也许会创造出更实用、更经济、更耐用的产品。
为了激发创造性思维,下列是设计和分析的建议规则。前六个规
则对设计者来说特别适用。
1.要有创造性的利用所需要的物理性质和控制过程。2.认识负载产生的影响及其意义。3.预测没有想到的负载。4.创造出对载荷更为有利的条件。
5.提供良好的应力分布和最小的刚度条件。6.运用最简单的方程来优化体积和面积。7.选择组合材料。8.仔细选择所备的原料和不可缺少的组件。
9.调整有效的设计方案,以适应生产过程和降低成本。10.规定好准确的位置条件为了使组件安装时不干涉。
机械设计包括一下内容:
1.对设计过程、设计所需要公式以及安全系数进行介绍。
2.回顾材料特性、静态和动态载荷分析,包括梁、振动和冲击载荷。3.回顾应力的基本规律和失效分析。
4.介绍静态失效理论和静态载荷下机械断裂分析。
5.介绍疲劳失效理论并强调在压力条件下接近高循环的疲劳设计,这通常用在旋转机械的设计中。
6.深入探讨机械磨损机理、表面接触应力和表面疲劳现象。7.使用疲劳分析技术校核轴的设计。8.讨论润滑油膜与滚动轴承的理论和应用。
9.深入介绍直齿圆柱齿轮的动力学、设计和应力分析,并简单介绍斜齿轮、锥齿轮和涡轮有关方面的问题。
10.讨论弹簧设计、螺杆等紧固件的设计,包括传动螺杆和预紧固件。11.介绍盘式和鼓式离合器以及制动器的设计和技术说明。
机械设计
一台完整机器的设计是一个复杂的过程。机械设计是一项创造性的工作。设计工程师不仅在工作上要有创造性,还必须在机械制图、运动学、工程材料、材料力学和机械制造工艺学等方面具有深厚的基础知识。
任何产品在设计时第一步就是选择产品每个部分的构成材料。许多的材料被今天的设计师所使用。对产品的功能,它的外观、材料的
成本、制造的成本作出必要的选择是十分重要的。对材料的特性必须事先作出仔细的评估。
仔细精确的计算是必要的,以确保设计的有效性。在任何失败的情况下,最好知道在最初设计中有有缺陷的部件。计算(图纸尺寸)检查是非常重要的。一个小数点的位置放错,就可以导致一个本可以完成的项目失败。设计工作的各个方面都应该检查和复查。
计算机是一种工具,它能够帮助机械设计师减轻繁琐的计算,并对现有数据提供进一步的分析。互动系统基于计算机的能力,已经使计算机辅助设计(CAD)和计算机辅助制造(CAM)成为了可能。心理学家经常谈论如何使人们适应他们所操作的机器。设计人员的基本职责是努力使机器来适应人们。这并不是一项容易的工作,因为实际上并不存在着一个对所有人来说都是最优的操作范围和操作过程。另一个重要问题,设计工程师必须能够同其他有关人员进行交流和磋商。在开始阶段,设计人员必须就初步设计同管理人员进行交流和磋商,并得到批准。这一般是通过口头讨论,草图和文字材料进行的。
如前所诉,机械设计的目的是生产能够满足人类需求的产品。发明、发现和科技知识本身并不一定能给人类带来好处,只有当它们被应用在产品上才能产生效益。因而,应该认识到在一个特定的产品进行设计之前,必须先确定人们是否需要这种产品。
应当把机械设计看成是机械设计人员运用创造性的才能进行产品设计、系统分析和制定产品的制造工艺学的一个良机。掌握工程基础知识要比熟记一些数据和公式更为重要。仅仅使用数据和公式是不足以在一个好的设计中做出所需的全部决定的。另一方面,应该认真精确的进行所有运算。例如,即使将一个小数点的位置放错,也会使正确的设计变成错误的。
一个好的设计人员应该勇于提出新的想法,而且愿意承担一定的风险,当新的方法不适用时,就使用原来的方法。因此,设计人员必须要有耐心,因为 所花费的时间和努力并不能保证带来成功。一个全新的设计,要求屏弃许多陈旧的,为人们所熟知的方法。由于许多人墨守成规,这样做并不是一件容易的事。一位机械设计师应该不断地
探索改进现有的产品的方法,在此过程中应该认真选择原有的、经过验证的设计原理,将其与未经过验证的新观念结合起来。
新设计本身会有许多缺陷和未能预料的问题发生,只有当这些缺陷和问题被解决之后,才能体现出新产品的优越性。因此,一个性能优越的产品诞生的同时,也伴随着较高的风险。应该强调的是,如果设计本身不要求采用全新的方法,就没有必要仅仅为了变革的目的而采用新方法。
Mechanical Design Abstract: A machine is a combination of
mechanisms and other components which transforms,
es are engines, turbines, vehicles, hoists,
printing presses, washing machines, and movie of
the principles and methods of design that apply to machines also
apply to manufactured articles that are not true
term “mechanical design” is used in a broader sense than
“machine design” to include their motion and
structural aspects and the provisions for retention and enclosure
are considerations in mechanical ations occur in the
field of mechanical engineering, and in other engineering fields
as well, all of which require mechanical devices, such as switches,
cams, valves, vessels, and ds: Mechanical Design
mechanisms Design Process
The Design Process Designing starts with a need ng
apparatus may need improvements in durability, efficiency,
weight, speed, or apparatus may be needed to perform
a function previously done by men, such as computation,
assembly, or the objective wholly or partly In the
design preliminary stage, should allow to design the personnel
fully to display the creativity, not each kind of if has
had many impractical ideas, also can in the design early time,
namely in front of the plan blueprint is then, only
then does not send to stops up the innovation the
y, must propose several sets of design proposals,
then perform the the possibility very much in
the plan which finally designated, has used certain not in plan
some ideas which the general shape and a few
dimensions of the several components become apparent,
analysis can begin in analysis will have as its objective
satisfactory or superior performance, plus safety and durability
with minimum weight, and a competitive m
proportions and dimensions will be sought for each critically
loaded section, together with a balance between the strengths of
the several als and their treatment will be
important objectives can be attained only by
analysis based upon the principles of mechanics, such as those
of static for reaction forces and for the optimum utilization of
friction;of dynamics for inertia, acceleration, and energy;of
elasticity and strength of materials for stress and deflection;of
physical behavior of materials;and of fluid mechanics for
lubrication and hydrodynamic analyses may be made
by the same engineer who conceived the arrangement of
mechanisms, or, in a large company, they may be made by a
separate analysis division or research is a
reiterative and cooperative process, whether done formally or
informally, and the analyst can contribute to phases other than
his t design requires much research and
Concepts of an idea must be studied, tried,
and then either used or gh the content of each
engineering problem is unique, the designers follow the similar
process to solve the t liability suits designers
and forced in material selection, using the best the
process of material, the most common problems for five(a)don't
understand or not use about the latest application materials to
the best information,(b)failed to foresee and consider the
reasonable use material may(such as possible, designers should
further forecast and consider due to improper use
recent years, many products liability in litigation, the use of
products and hurt the plaintiff accused manufacturer, and won
the decision),(c)of the materials used all or some of the data, data,
especially when the uncertainty long-term performance data is
so,(d)quality control method is not suitable and unproven,(e)by
some completely incompetent persons choose
h to the above five questions analysis, may
obtain these questions is does not have the sufficient reason
existence the for avoid these questions to these
questions research analyses the appearance indicating the
gh uses the best choice of material method not
to be able to avoid having the product responsibility lawsuit,
designs the personnel and the industry carries on the choice of
material according to the suitable procedure, may greatly reduce
the lawsuit the see from the above discussion, the
choice material people should to the material nature, the
characteristic and the processing method have comprehensive
and the basic y, a design based upon
function, and a prototype may be its tests are satisfactory,
the initial design will undergo certain modifications that enable
it to be manufactured in quantity at a lower
subsequent years of manufacture and service, the design is likely
to undergo changes as new ideas are conceived or as further
analyses based upon tests and experience indicate
Rules for Design In this section it
is suggested that, applied with a creative attitude, analyses can
lead to important improvements and to the conception and
perfection of alternate, perhaps more functional, economical,
and durable stimulate creative thought, the
following rules are suggested for the designer and
first six rules are particularly applicable for the analyst.1.A
creative use of need of physical properties and control
ize functional loads and their
pate unintentional more
favorable loading e for favorable stress
distribution and stiffness with minimum basic
equations to proportion and optimize
materials for a combination of carefully, stock
and integral a functional design to fit the
manufacturing process and reduce e for accurate
location and noninterference of parts in ery
design covers the following es an introduction
to the design process , problem formulation ,safety
s the material properties and static and dynamic
loading analysis , Including beam , vibration and impact
s the fundamentals of stress and defection
uces fatigue-failure theory with the emphasis on
stress-life approaches to high-cycle fatigue design, which is
commonly used in the design of rotation ses
thoroughly the phenomena of wear mechanisms, surface contact
stresses ,and surface igates shaft design using the
fatigue-analysis ses fluid-film and rolling-element bearing theory and application
a thorough introduction to the kinematics, design
and stress analysis of spur gears , and a simple introduction to
helical ,bevel ,and worm ses spring design
including compression ,extension and torsion
with screws and fasteners including power screw and preload
uces the design and specification of disk and
drum clutches and e Design The complete design
of a machine is a complex machine design is a
creative t engineer not only must have the creativity
in the work, but also must in aspect and so on mechanical
drawing, kinematics, engineerig material, materials mechanics
and machine manufacture technology has the deep elementary
of the first steps in the design of any product is
to select the material from which each part is to be
us materials are available to today's
function of the product, its appearance, the cost of the material,
and the cost of fabrication are important in making a selection.A
careful evaluation of the properties of al must be made
prior to any l calculations are necessary to
ensure the validity of a case of any part failures, it is
desirable to know what was done in originally designing the
defective checking of calculations(and drawing
dimensions)is of utmost misplacement of one
decimal point can ruin an otherwise acceptable
aspects of design work should be checked and
computer is a tool helpful to mechanical designers to lighten
tedious calculations, and provide extended analysis of available
ctive systems, based on computer capabilities, have
made possible the concepts of computer aided design(CAD)and
computer-aided manufacturing(CAM).How does the
psychologist frequently discuss causes the machine which the
people adapts them to s personnel''s basic
responsibility is diligently causes the machine to adapt the
certainly is not an easy work, because certainly does
not have to all people to say in fact all is the most superior
operating area and the operating r important
question, project engineer must be able to carry on the exchange
and the consultation with other concerned the
initial stage, designs the personnel to have to carry on the
exchange and the consultation on the preliminary design with
the administrative personnel, and is generally is
through the oral discussion, the schematic diagram and the
writing material carries front sues, the machine design goal
is the production can meet the human need the
invention, the discovery and technical knowledge itself certainly
not necessarily can bring the advantage to the humanity, only
has when they are applied can produce on the product the
, should realize to carries on before the design in a
specific product, must first determine whether the people do
need this kind of product Must regard as the machine design is
the machine design personnel carries on using creative ability the
product design, the system analysis and a formulation product
manufacture technology good the project
elementary knowledge to have to memorize some data and the
formula is more important merely service data and the
formula is insufficient to the completely decision which makes in
a good design the other hand, should be earnest
precisely carries on all example, even if places
wrong a decimal point position, also can cause the correct design
to turn wrongly.A good design personnel should dare to propose
the new idea, moreover is willing to undertake the certain risk,
when the new method is not suitable, use original
ore, designs the personnel to have to have to have
the patience, because spends the time and the endeavor
certainly cannot guarantee brings successfully.A brand-new
design, the request screen abandons obsoletely many, knows
very well the method for the e many person of
conservativeness, does this certainly is not an easy matter.A
mechanical designer should unceasingly explore the
improvement existing product the method, should earnestly
choose originally, the process confirmation principle of design in
this process, with has not unified it after the confirmation new
idea.
第二篇:机械类(焊接方面)外文翻译
水下焊接技术发展史
水下焊接技术是开发海洋、开采海底石油以及组装、维修诸如采油平台、输油管线和海底仓等大型海洋结构的关键技术之一, 也是舰船应急修理、海上救助、桥梁架设等工作的必要技术手段。核电是世界电力发展的趋势,在核电站内部,核反应堆压力容器(RPV)因为长期在水中工作,容易受到应力腐蚀裂纹的破坏,核电结构修复时,会遇到很多挑战。为了减少工作人员所受的核辐射,经常会采用水下焊接方法。水下焊接的分类一般将水下熔焊分为三大类: 湿法、干法和局部干法。其中干法又可以分为高压干法水下焊接和常压干法水下焊接。局部干法则包括排水罩式、高压水帘式、钢刷式、移动气箱式和等离子弧 MIG 局部干法等。采用的焊接方法一般有药皮焊条焊接,
GTAW,GMWA以及 FCAW。水下焊接除熔焊之外还有爆炸焊和
FSW(friction stitch welding 摩擦叠焊), 这两种方法都属于固相连接技术。以下为水下焊接的发展历程: 水下湿法焊接技术
1802 年, 一位名叫 Humphrey的学者指出电弧能够在水下连续燃烧, 即指出了水下焊接的可能性, 然而其实际应用却是在 100 多年以后,
在不可能把结构物移到陆地上进行焊接的情况下才做到的。1917 年,英国海军船坞的焊工采用水下焊接的方法来封堵位于轮船水下部分漏
水的铆钉缝隙, 这是水下焊接的首次应用。第 一篇正式发表的关于水下焊接研究工作的论文, 是在 1933 年由 Hibshrman 和 Jensen 共同完成的。1932 年, Khrenov 发明了厚药皮水下专用焊条,在焊条外表面涂有防水层, 使水下焊接电弧的稳定性得到了一定程度的改善。到第二次世界大战结束时, 水下焊接技术在打捞沉船等方面已经占有重要地位。1971 年, Humble 石油公司对墨西哥湾钻采平台的水下焊接修理工作是水下焊接技术第一次应用于海洋石油工程。1985 年产生了第一批经过认可的潜水焊工,并制定了水深小于 100m 的水下湿法焊接工艺。1987 年, 水下湿法焊接技术在核电厂不锈钢管道的修理工作中得到应用。上世纪 90 年代, 随着要求修理的水下工程结构的增多以及船坞修理成本的增加,湿法焊接技术得到了进一步的发展。水下焊条的发展对水下湿法焊接的应用起着重要的作用。英国 Hydroweld 公司发展了多种水下焊条,取得了很好的实用效果。美国专利焊条—7018`s 焊条药皮上有一层铝粉, 水下焊接时能产生大量的气体,避免焊缝金属受到侵蚀。德国 Hanover 大学基于渣-气联合保护对熔滴过渡过程的影响和保护机理研制开发了双层自保护药芯焊条。通常水下湿法焊接的水深不超过 100 m, 目前努力的方向是实现 200 m水深湿法焊接技术的突破。早在上世纪 50 年代, 水下湿法焊条电弧焊就已经在我国得到应用。上世纪 60 年代我国开始自行开发水下专用焊条。华南理工大学研制的水下焊条在 30 m水深以内可以获得良好的焊接性能。水下干法焊接技术
● 水下高压干法焊接技术
高压干法水下焊接的设想是 1954 美国首先提出的, 1966 年正式用于生产, 主要用于海底管道的修复。目前最大使用水深在 300 m 左右。该焊接方法中, 气室底部是开口的, 通入气压稍大于工作水深压力的气体, 把气室内的水从底部开口处排出, 焊接是在干的气室中进行的。一般采用 MIG 焊或 TIG 焊,是当前水下焊接中质量最好的方法之一, 基本上可达到陆上焊缝的水平。上世纪 70 年中期, 无人高压焊接研究装置开发成功。德国、挪威、美国、英国都在上世纪 90 年代开始此类研究并建立了无人高压焊接研究中心。从上世纪 80 年代中期开始, 一些研究中心就开始研究 300~500 m 水深的 GTAW 自动焊接系统和工艺,
或者是检验 500~1000 m水深替换性焊接技术的适应性了。现在法国、德国、挪威、美国的高压焊接研究中心的实验舱作业压力都可以达到相当于1000 m 水深。从上世纪 90 年代开始石油公司的作业已经开始进入更深的水域。第一个在这种水深下进行作业的公司应该是巴西石油公司(即巴西国家石油公司), 其在亚马孙盆地的作业水深达到 1 000
m。在我国, 随着海洋石油工业的发展, 迫切需要开发具有自主知识产权的高压干法焊接技术。在 2002 年的国家“863”计划中就有关于水下高压干法焊接技术的研究项目。由中国海洋石油工程公司、北京石油化工学院、石油大学、上海交通大学、哈尔滨工程大学联合研发设计的最大焊接水深为 60 m。目前, 项目基本完成, 即将进行海试。● 水下常压干法焊接技术
水下高压干法焊接的焊接质量虽然较好, 但其局限性较大, 尤其是随着水深的增加, 电弧周围的气压不断增加, 容易破坏电弧的稳定性而产生焊接缺陷。而且在没有达到焊接全自动化的情况下, 需要潜水焊工的辅助操作, 如果水深超过潜水极限或者潜水成本过高则无法实施。在技术水平还无法解决这些问题的时候, 为了克服水下高压干法焊接的不足, 1977 年制造出水下常压干法焊接设备。1977年, 法国 LPS公司首先采用这种方法在北海水深150 m 处成功地焊接了直径 426 mm的海底管道。我国目前还没有水下常压干法焊接设备。3 水下局部干法焊接技术
水下局部干法焊接技术有很多方法。上世纪 70年代后期, 哈尔滨焊接研究所在上海海难救助打捞局和天津石油勘探局的协助下, 开发了水下局部排水CO2 气体保护焊接技术, 简称 LD-CO2 焊接法, 属于排水罩式局部干法, 采用此方法可以完成多项水下施工任务。高压水帘式是由日本应用的一种方法, 为了克服水帘式的一些缺点, 日本又将其发展为钢刷式。移动气箱式于 1968 年由美国首先提出, 后由美英跨国公司应用于生产。法国最近还研究了一种旋罩式的水下局部干法焊接技术。另外, 等离子弧 MIG 局部干法水下焊接也是一种很有前途的局部干法焊接技术。水下固相连接技术 ● 爆炸焊
在上世纪 70 年代后期, 位于福内斯巴罗的英国水下管道工程公司
研制成功了 1 套完整的管道修补系统, 首次采用了爆炸焊技术。● 摩擦叠焊
英国焊接研究所(TWI)在上世纪 80 年代中期开发了 1 套用于水下环境的螺柱摩擦焊系统。该系统已经在相当于 600 m 水深的压力下进行试验, 结果表明焊接效果不受水深影响, 而且业已证明, 该系统可以有效地使用 ROV(水下作业机器人)。最近的发展是试图把水下摩擦焊由螺柱摩擦焊扩展到具有缝合焊缝的摩擦叠焊。目前北京石油化工学院已经开始了此方面的研究工作并获得了国家自然科学基金的支持。水下焊接技术在 21 世纪的发展趋势
虽然上述各种水下焊接方法自从其出现以来,都依靠其各自的优势 在特定的方面得到了应用。但从目前来看 水下焊接的研究还不能完全满足水下焊接施工的要求 未来应从以下几个方面做重点研究:
(1)从焊接冶金和保证焊接质量的角度看,干法水下焊接是最为有利的,所以,近年来高压干法水下焊接技术得到了进一步的发展,但仍然不能满足实际的需求。目前,对于高压电弧的理论研究还不十分完整,如何采用多信息融合技术达到对焊接过程的智能监控也已成为高压干法焊接领域的新课题。
(2)由于水下焊接机器人工作环境的特殊性,增加了水下焊接机器人的应用难度。未来水下焊接机器人应该能够完成焊缝的预处理、焊接及焊缝检测工作,因此,要努力做好包括水下机器人的精确定位技术、机器人手臂的运动控制技术、基于视觉传感系统的焊缝空间位置的检测、跟踪以及水下焊接质量控制等几个方面的工。
(3)焊接模拟技术的出现及发展使焊接技术正在发生着由经验到科学,由定性到定量的飞跃。近年来,焊接数值模拟技术不断向深度、广度发展,但对水下焊接的模拟研究还比较滞后,应重视和加快这方面的数值模拟研究。
(4)采用计算机仿真技,比在实际物理模型上的安装、调试、试验等工作量要小得多,并且周期短,投资少,显示出许多优点。近年来,它在焊接工艺的制定、焊接设备的研制以及控制系统的改进等方面的研究中都有应用。通过焊接仿真,有助于构思新方案,并能提前
发现存在的问题,这也是以后应当研究的一个领域。
随着水下焊接新需求的出现以及科学技术的发展,新的水下焊接方法和焊接手段将会不断地涌现并显示它们的独特优势。展望未来,迈向高科技领域的水下焊接技术必将取得更大辉煌。
第三篇:外文翻译
当今时代是一个自动化时代,交通灯控制等很多行业的设备都与计算机密切相关。因此,一个好的交通灯控制系统,将给道路拥挤,违章控制等方面给予技术革新。随着大规模集成电路及计算机技术的迅速发展,以及人工智能在控制技术方面的广泛运用,智能设备有了很大的发展,是现代科技发展的主流方向。本文介绍了一个智能交通的系统的设计。该智能交通灯控制系统可以实现的功能有:对某市区的四个主要交通路口进行控制:个路口有固定的工作周期,并且在道路拥挤时中控制中心能改变其周期:对路口违章的机动车能够即时拍照,并提取车牌号。在世界范围内,一个以微电子技术,计算机和通信技术为先导的,一信息技术和信息产业为中心的信息革命方兴未艾。而计算机技术怎样 与实际应用更有效的结合并有效的发挥其作用是科学界最热门的话题,也是当今计算机应用中空前活跃的领域。本文主要从单片机的应用上来实现十字路口交通灯智能化的管理,用以控制过往车辆的正常运作。
研究交通的目的是为了优化运输,人流以及货流。由于道路使用者的不断增加,现有资源和基础设施有限,智能交通控制将成为一个非常重要的课题。但是,智能交通控制的应用还存在局限性。例如避免交通拥堵被认为是对环境和经济都有利的,但改善交通流也可能导致需求增加。交通仿真有几个不同的模型。在研究中,我们着重于微观模型,该模型能模仿单独车辆的行为,从而模仿动态的车辆组。
由于低效率的交通控制,汽车在城市交通中都经历过长时间的行进。采用先进的传感器和智能优化算法来优化交通灯控制系统,将会是非常有益的。优化交通灯开关,增加道路容量和流量,可以防止交通堵塞,交通信号灯控制是一个复杂的优化问题和几种智能算法的融合,如模糊逻辑,进化算法,和聚类算法已经在使用,试图解决这一
问题,本文提出一种基于多代理聚类算法控制交通信号灯。
在我们的方法中,聚类算法与道路使用者的价值函数是用来确定每个交通灯的最优决策的,这项决定是基于所有道路使用者站在交通路口累积投票,通过估计每辆车的好处(或收益)来确定绿灯时间增益值与总时间是有差异的,它希望在它往返的时候等待,如果灯是红色,或者灯是绿色。等待,直到车辆到达目的地,通过有聚类算法的基础设施,最后经过监测车的监测。
我们对自己的聚类算法模型和其它使用绿灯模拟器的系统做了比较。绿灯模拟器是一个交通模拟器,监控交通流量统计,如平均等待时间,并测试不同的交通灯控制器。结果表明,在拥挤的交通条件下,聚类控制器性能优于其它所有测试的非自适应控制器,我们也测试理论上的平均等待时间,用以选择车辆通过市区的道路,并表明,道路使用者采用合作学习的方法可避免交通瓶颈。
本文安排如下:第2部分叙述如何建立交通模型,预测交通情况和控制交通。第3部分是就相关问题得出结论。第4部分说明了现在正在进一步研究的事实,并介绍了我们的新思想。
The times is a automation times nowadays,traffic light waits
for much the industey equipment to go hand in hand with the
computer under the control ore,a good traffic light
controls system,will give road aspect such as being
crowded,controlling against rules to give a technical
the fact that the large-scale integrated circuit
and the computer art promptness develop,as well as artificial
intelligence broad in the field of control technique
applies,intelligence equipment has had very big
development,the main current being that modern science and
technology develops main body of a book is
designed having introduccd a intelligence traffic light
function being intelligence traffic light
navar’s turn to be able to come true has:The crossing carries
out supervisory control on four main traffic of some downtown
area;Every crossing has the fixed duty period,charges centrefor
being able to change it’s period and in depending on a road
when being crowded;The motro vehicle breaking rules and
regulations to the crossing is able to take a photo
immediately,abstracts and the vehicle shop world
range ,one uses the microelectronics technology,the computer
and the technology communicating by letter are a
guide’s,centering on IT and IT industry information revolution
is in the ,how,computer art applies more effective
union and there is an effect’s brought it’s effect into play with
reality is the most popular topic of scientific community,is also
that computer applications is hit by the unparalleled active field
main body of a book is applied up mainly from
slicing machine’s only realizing intellectualized administration
of crossroads traffic light,use operation in controlling the
vehicular traffic ortation research has the goal to
optimize transportation flow of people and the number
of road users constantly increases, and resources provided by
current infras-tructures are limited, intelligent control of traffic
will become a very important issue in r, some
limitations to the usage of intelligent tra?c control
ngtraffic jams for example is thought to be beneficial
to both environment and economy, butimproved traffic-flow
may also lead to an increase in demand [Levinson, 2003].There
are several models for traffic our research we focus
on microscopicmodels that model the behavior of individual
vehicles, and thereby can simulate dynam-ics of groups of
ch has shown that such models yield realistic
behavior[Nagel and Schreckenberg, 1992, Wahle and
Schreckenberg, 2001].Cars in urban traffic can experience long
travel times due to inefficient traffic light l
control of traffic lights using sophisticated sensors and intelligent
optimizationalgorithms
capacity and traffic
might
flow, and
therefore
can prevent
bevery
tra?c
zation of traffic light switching increasesroad
c light control is acomplex optimization
problem and several intelligent algorithms, such as fuzzy logic,
evo-lutionary algorithms, and reinforcement learning(RL)have
already been used in attemptsto solve this paper we describe
a model-based, multi-agent reinforcement learningalgorithm for
controlling traffic our approach, reinforcement learning
[Sutton and Barto, 1998, Kaelbling et al., 1996]with road-user-based value functions [Wiering, 2000] is used to determine
optimal decisionsfor each traffic decision is based on a
cumulative vote of all road users standingfor a traffic junction,
where each car votes using its estimated advantage(or gain)of
settingits light to gain-value is the difference between
the total time it expects to waitduring the rest of its trip if the
light for which it is currently standing is red, and if it is
waiting time until cars arrive at their destination is estimated by
monitoring cars flowingthrough the infrastructure and using
reinforcement learning(RL) compare the
performance of our model-based RL method to that of other
controllersusing the Green Light District simulator(GLD).GLD is a
traffic simulator that allows usto design arbitrary infrastructures
and traffic patterns, monitor traffic flow statistics such asaverage
waiting times, and test different traffic light
experimental resultsshow that in crowded traffic, the RL
controllers outperform all other tested non-
also test the use of the learned average
waiting times for choosing routes of cars through the city(co-learning), and show that by using co-learning road users can
avoidbottlenecks.
第四篇:外文翻译
设计一个位于十字路口的智能交通灯控制系统
摘要:本文模型使用模糊本体的交通灯控制域,并把它应用到控制孤立十字路口。本文最重要的目的之一是提出一个独立的可重复使用的交通灯控制模块。通过这种方式,增加软件的独立性和为其他的软件开发活动如测试和维护,提供了便利。专家对本体论进行手动的开发和评估。此外,交通数据提取和分类路口使用的人工神经网络的图像处理算法。根据预定义的XML架构,这种信息转化为XML实例映射到适合使用模糊推理引擎的模糊规则的模糊本体。把本系统的性能与其他类似的系统性能进行比较。比较结果显示:在所有的交通条件下,在每个周期中,对每辆车它有低得多的平均延迟时间与其他的控制系统相比。
关键词:模糊本体,智能代理,智能交通系统(ITS),交通信号灯控制(TLC),孤立的十字路口,图像处理,人工神经网络
1.引言
作为城市交通增加的结果,道路网络的能力有限和发展交通工具和方法的技术方面,许多实体,关系,情况和规则已经进入交通灯控制域和转化成为一个知识领域。这个领域的建模知识帮助交通代理和应用有效地管理关于实时条件下的交通。全面知识建模领域的一个最合适的方法是使用本体概念。“本体论是一个正式的、明确的一个共享的概念化的规范。以前的模型是基本的本体建设的基础,为下列建立一个共享的语义丰富的知识域。除了本体作为概念化的形式主义的重要性,它有可能超过所代表的数据。这种能力将提高有关性能的决定和其他非智能系统的功能特点。在近年来,本体论上的研究正成为一个新的热点话题在不同的活动,如人工智能,知识管理,语义网络,电子商务和几个其他应用领域。这些领域之一是智能交通系统。一些
努力已制成这个通过展示和使用本体检测交通领域拥塞,管理非城市道路气象事件,驾驶阿德福—索里系统,共享和整合一个智能交通系统。本文的目的是介绍一个红绿灯有效控制孤立交叉口这方面的知识重用的控制本体。这种新的办法适用于智能代理使用知识决策模糊。该系统采用的图像来自安装了监控摄像机拍摄的路口。这些图像处理利用图像处理算法和神经网络的方法,然后发送到一个智能代理。第2节中,我们将简要地解释了在这项工作中运用的技术包括seman-TIC网络技术,智能代理技术和交通的回地面光控制方法。在第3节,新的系统架构是基于分层语义网络架构。第4节介绍交通灯控制的模糊本体的建设。第五节从路口提取的图像信息解释。在第6节,智能系统的运作被完整描述,最后在第7节对所提出的方法进行评估,对结论进行阐述。
2.背景
本节说明在这项工作中的应用技术包括语义网络技术,特别本体和模糊本体。此外,国家的交通灯控制的艺术方法是简要介绍。2.1.语义网络技术
语义网络被定义为当前Wed的延伸,这些网站的信息都给出明确的含义;使电脑与人更好的合作。有几层语义Web的建议源自伯纳斯滞后阶段。在此类别中的所有规则如表1所示。图.4显示输出模式的示意图。本次评选有助于智能系统,以确定下一步的阶段测序。
另一种模糊的规则类别涉及估计优化周期时间。这些规则的模糊变量是天气条件,时间,每天平均车辆拥堵情况。出于这个原因,60个模糊规则被定义了。从气象研究所取得气象条件。日期和时间也是在交通专家的知识的基础上以模糊变量形式预先定义的。图5显示日期,时间和周期时间的隶属函数。当天的参数是在日历基础上基于假期和正常的一天与周期时间量的关系预定义的。例如,假期期间的周期时间是较平日少。因此,平日的隶属度比假期多。
例如一个阶段选型的模糊规则如下所述:“如果一个路口的类型是四的方式,平均车辆拥堵低,平均行人拥堵是中等,然后相类型是简单的两阶段”。此外,为周期时间估计的模糊规则表示如下:“如
果天气条件是晴天,时间是早晨,天是正常的,平均车辆拥堵是低,则周期时间短”。在此类别中的所有规则都列在附录A。
在此步骤结束时,应该对交通灯逻辑控制的项目的有效性进行评估。此功能是使用专家的意见。评价过程的主要目的是显示发展的本体和其相关的软件环境的用处。虽然所有的信息,尤其是交通灯控制规则已提取国际标准和科学交通文学,专家的知识优势是他们最后的正确性验证标准。所有模糊规则,包括优化周期时间和相位类型的规则,在这个过程中,准备以调查问卷形式和展现给一些专家包括从德黑兰警察局交通上校和两名来自德黑兰的交通组织工程师。由于德尔菲专家的意见,约有84%的淘汰型规则和优化周期时间的87%被接受。此外,所有交通逻辑控制的元素包括概念,关系,属性和公理都被这些专家进行了评估和验证。我们评估逻辑交通控制是基于理论知识的。在这个过程中进行了两项活动,包括检查的要求和能力的问题,并在目标应用环境测试本体。由于逻辑交通控制已建成的基础上,如指定要求优化循环时间,逐步淘汰型,交通的移动和优化绿灯时间,每个阶段的序列中,第一项活动是最好的结果。逻辑交通控制满足所有的交通灯控制的需求,并能回答的能力问题。绩效评估机制,可以支持这种说法。在部分实验结果我们验证了这一过程。
第五篇:外文翻译
中原工学院毕业设计(论文)译文
超声测距系统设计
原文出处:传感器文摘 布拉福德:1993年第13页
摘要:超声测距系统技校在工业场车辆导航水声工程等领域都具有了广泛的应用价值,目前已应用于物理测量,机器人自动导航以及空气中与水下的目标探测、识别定位等场合,因此,深入研究超声的探测理论和方法具有重要的实践意义,为了进一步提高测量的精确度,满足工程人员对测量精度测距量程和测距仪使用的要求,本文研制了一套基于单片机的使拱式超声测距系统。关键词:超声波 测距仪 单片机
1、前言
随着科技的发展,人们生活水平的提高,城市发展建设加快,城市给排水系统也有较大发展,其状况不断改善,但是,由于历史原因合成时间性的许多不可预见因素,城市给排水系统,特别是排水系统往往落后于城市建设,因此,经常出现开挖已经建设好的建筑设施来改造排水系统的现象。城市污水给人们带来的困扰,因此箱的排污疏通对大城市给排水系统污水理,人们生活舒适显得非常重要。而设计研制箱涵排水疏通移动机器人的自动控制系统,保证机器人在箱涵中自由排污疏通,是箱涵排水系统疏通机器人的设计研制的核心部分,控制系统核心部分就是超声波测仪的研制。因此,设计好的超声波测距仪就显得非常重要了。
1.1课题背景
随着经济的发展与汽车科学技术的进步,公路交通呈现出行驶高速化、车流密集化和驾驶员非职业化的趋势。同时,随着汽车工业的飞速发展,汽车的产量和保有量都在急剧增加。但公路发展、交通管理却相对落后,导致了交通事故与日剧增,城市里尤其突出。智能交通系统ITS是目前世界上交通运输科学技术的前沿技术,它在充分发挥现有基础设施的潜力,提高运输效率,保障交通安全,缓解交通赌塞,改善城市环境等方面的卓越效能,已得到各国政府的广泛关注。中国政府也高度重视智能交通系统的研究开发与推广应用。汽车防撞系统作为ITS 发展的一个基础,它的成功与否对整个系统有着很大的作用。从传统上说,汽车的安全可以分为两个主要研究方向:一是主动式安全技术,即防止事故的发生,该种方式是目前汽车安全研究的最终目的;二是被动式安全技术,即事故发生后的乘员保护。目前汽车安全领域被动安全研究较多,主要从安全气囊、ABS(防抱死系统)和悬架等方面着手,以保证驾乘人员的安全。从经济性和安全性两方面来说,中原工学院毕业设计(论文)译文
这些被动安全措施是在事故发生时刻对车辆和人员进行保护,有很大的局限性,因而车辆的主动安全研究尤为重要,引出了本文研究的基于单片机的超声波测距系统。这个系统是一种可向司机预先发出视听语音信号的探测装置。它安装在汽车上,能探测企图接近车身的
行人、车辆或周围障碍物;能向司机及乘员提前发出即将发生撞车危险的信号,促使司机采取应急措施来应付特殊险情,避免损失。
1.2 课题设计的意义
随着现代社会工业化程的发展,汽车这一交通工具正为越来越多的人所用,但是随之而来的问题也显而易见,那就是随着车辆的增多,交通事故的频繁发生,由此导致的人员伤亡和财产损失数目惊人。对于公路交通事故的分析表明,80%以上的车祸事由于驾驶员反应不及所引起的,超过65%的车辆相撞属于追尾相撞,其余则属于侧面相撞。奔驰汽车公司对各类交通事故的研究表明:若驾驶员能够提早1S 意识到有事故危险并采取相应的正确措施,则绝大多数的交通事故都可以避免。因此,大力研究开发如汽车防撞装置等主动式汽车辅助安全装置,减少驾驶员的负担和判断错误,对于提高交通安全将起到重要的作用。显然,此类产品的研究开发具有极大的实现意义和广阔的应用前景。
1.3超声波测距在汽车上应用的介绍
超声波倒车测距仪(俗称电子眼)是汽车倒车防撞安全辅助装置,能以声音或者更为直观的数字形式动态显示周围障碍物的情况。其较早的产品是用蜂鸣器报警,蜂鸣声越急,表示车辆离障碍物越近。后继的产品可以显示车后障碍物离车体的距离。其大多数产品探测范围在0.4~1.5m,有的产品能达到0.35~2.5m,并有距离显示、声响报警、区域警示和方位指示,有些产品还具备开机自检功能。目前市场上还出现了具有语音报警功能的产品。这些产品存在的主要问题是测量盲区大,报警滞后,未考虑汽车制动时的惯性因素,使驾驶者制动滞后,抗干扰能力不强,误报也较多。汽车防撞雷达之所以能实现防撞报警功能,主要有超声波这把无形尺子, 它测量最近障碍物的距离, 并告诉给车主。其实超声测距原理简单: 它发射超声波并接收反射回波, 通过单片机计数器获得两者时间差t, 利用公式S=Ct/2计算距离, 其中S为汽车与障碍物之间的距离, C为声波在介质中的传播速度。
本文介绍的超声测距系统共有2只超声波换能器(俗称探头),分别布置在汽车的后左、后右2个位置上。能检测前进和倒车方向障碍物
距离, 通过后视镜内置的
中原工学院毕业设计(论文)译文
显示单元显示距离和方位, 发出一定的声响, 起到提示和警戒的作用。系统采用一片STC89C52单片机对两路超声波信号进行循环采集。超声波是指频率高于20HHZ的机械波。为了以超声波作为检测手段,必须产生超生波和接收超声波。完成这种功能的装置就是超声波传感器,习惯上称为超声波换能器或超声波探头。超声波传感器有发送器和接收器,但一个超声波传感器也可具有发送和接收声波的双重作用。超声波传感器是利用压电效应的原理将电能和超声波相互转化,即在发射超声波的时候,将电能转换,发射超声波;而在收到回波的时候,则将超声振动转换成电信号。超声波测距的原理一般采用渡越时间法。首先测出超声波从发射到遇到障碍物返回所经历的时间,再乘以超声波的速度就得到二倍的声源与障碍物之间的距离。测量距离的方法有很多种,短距离的可以用尺,远距离的有激光测距等,超声波测距适用于高精度的中长距离测量。因为超声波在标准空气中的传播速度为331.45米/秒,由单片机负责计时,单片机使用12.0M晶振,所以此系统的测量精度理论上可以达到毫米级。由于超声波指向性强,能量消耗缓慢,在介质中传播距离远,因而超声波可以用于距离的测量。利用超声波检测距离,设计比较方便,计算处理也较简单,并且在测量精度方面也能达到要求。超声波发生器可以分为两类:一类是用电气方式产生超声波,一类是用机械方式产生超声波。本设计属于近距离测量,可以采用常用的压电式超声波换能器来实现触发单元。
利用超声波测距的工作,就可以根据测量发射波与反射波之间的时间间隔,从而达到测量距离的作用。其主要有三种测距方法:
(1)相位检测法,相位检测法虽然精度高,但检测范围有限;
(2)声波幅值检测法,声波幅值检测法易受反射波的影响;
(3)渡越时间检测法,渡越时间检测法的工作方式简单,直观,在硬件控制和软件设计上都非常容易实现。其原理为:检测从发射传感器发射超声波,经气体介质传播到接收传感器的时间,这个时间就是渡越时间。本设计的超声波测距就是使用了渡越时间检测法。在移
动车辆中应用的超声波传感器,是利用超声波在空气中的定向传播和固体反射特性(纵波),通过接收自身发射的超声波反射信号,根据超声波发出及回波接收的时间差和传播速度,计算传播距离,从而得到障碍物到车辆的距离。
中原工学院毕业设计(论文)译文 超声波测距原理
2.1 压电式超声波发生器原理
压电式超声波发生器实际上是利用压电晶体的谐振来工作的。超声波发生器内部结构,它有两个压电晶片和一个共振板。当它的两极外加脉冲信号,其频率等于压电晶片的固有振荡频率时,压电晶片将会发生共振,并带动共振板振动,便产生超声波。反之,如果两极板间未加电压,当共振板接收到超声波时,将压迫压电晶片做振动,将机械能转换为电信号,这是它就成为超声波接收器了。
测量脉冲到达时间的传统方法是以拥有固定参数的接收信号开端为基础的。这个信号恰恰选于噪音水平之上,然而脉冲到达时间被定义为脉冲信号刚好超过界限的第一时刻。一个物体的脉冲强度很大程度上取决于这个物体的自然属性尺寸还有它与传感器的距离。进一步说,从脉冲起始点到刚好超过界限之间的时间段随着脉冲的强度而改变。结果,一种错误便出现了——两个拥有不同强度的脉冲在不同时间超过界限却在同一时刻到达。强度较强的脉冲会比强度较弱的脉冲超过界限的时间早点,因此我们会认为强度较强的脉冲属于较近的物体。
2.2 超声波测距原理
超声波发射器向某一方向发射超声波,在发射时刻的同时开始计时,超声波在空气中传播,途中碰到障碍物就立即返回来,超声波接收器收到反射波就立即停止计时。超声波在空气中的传播速度为340m/s,根据计时器记录的时间t,就可以计算出发射点距离障碍物的距离(s),即:s=340t/2
中原工学院毕业设计(论文)译文
3、超声波测距系统的电路设计
系统的特点是利用单片机控制超声波的发射和超声波自发射至接
受往返时间的计时,单片机选用C51,经济易用,且片内有4K的ROM,便于编程。电路的原理如图1所示。
图1 电路原理图
中原工学院毕业设计(论文)译文
3.1 40kHz脉冲的产生与超声波发射
测距系统中的超声波传感器采用UCM40的压电陶瓷,它的工作电压是40kHz的脉冲信号,这由单片机执行下面的程序来产生。puzel:mov 14h,#12h
here: cp1.0;
nop;
nop;
nop;
djnz 14h,here;
Ret
前方测距电路的输出端接单片机P1.0端口,单片机执行上面的程序后,在P1.0端口输出一个40khz的脉冲信号,经过三极管T放大,驱动超声波发射头UCM40T,发出40khz的脉冲超声波,且持续发射200ms。右侧合作侧测距电路的输入端分别接P1.1和P1.2端口,工作原理和前方测距电路相同。
超声波发射持续200ms 输出40kHz方波
3.2 超声波的接收与处理
接收头采用与发射头配对的UCM40R,将超声波调制脉冲变为电压信号,经运算放大器ic1a和ic1b两级放大后加至IC2,。IC2是带有锁定环的音频译码集成块LM567,内部压控振荡器的中心频率f0=1/1.1R8C3,电容C4决定其带宽。调节R8在发射的载频上,则LM567输入信号大于25mv,输出端8脚由5由高电平跃变为低电平,作为中断请求信号,送至单片机处理。
前方测距电路的输出端接至单片机INT0端口,中断优先级最高,左、右测距电路的输出通过与门IC3A的输出接单片机的INT1端口,同时单片机P1.3和P1.4接到IC3A的输入端,中断源的识别由程序查
询来处理,中断优先级为先右后左。部分源程序如下: receive1:push psw
push acc
clr ex1;关中断源1
jnb p1.1,right;P1.1引脚为0,转至右侧距电路中断服务程序
jnb p1.2,left;P1.2 引脚为0,转至左测距中断电路服务程序
returne:SETB EX1;
开外部中断1
pop acc
中原工学院毕业设计(论文)译文
pop psw
reti right:
...;
右测距电路中断服务程序入口
ajmp return
left:
...;
左测距电路中断服务程序入口
ajmp return
3.3 计算超声波传播时间
在启动发射电路的同时启动单片机内部的定时器T0,利用定时器的计数功能,记录超声波发射的时间和受到反射波的时间。当收到超声波反射波时,接受电路输出端产生一个负跳变,在INT0或INT1端产生一个中断请求信号,单片机响应外部中断请求,执行外部中断服务子程序,读取时间差,计算距离。其部分源程序如下:
RECEIVEO: PUSH PSW
PUSH ACC CLR EX0;
关外部中断0 读取时间值
MOV R7,TH0;MOV R6,TL0 CLR C MOV A,R6 SUBB
A,#0BBH;MOV 31H,A;MOV A,R7 SUBB A,#3CH MOV 30H,A SETB
EX0;POP ACC
POP PSW
RETI 对于一个平坦的目标,测量距离包括两个阶段:粗糙的测量和精细的测量。第一步:脉冲的传送产生一种简单的超声波
第二步:根据公式改变回波放大器的获得量直到回拨被检测到。第三步:检测两种回波的振幅与过零时间。
计算时间值 存储结果
开外部中断0
中原工学院毕业设计(论文)译文
第四步:设置回波放大器的所得规格输出,假定是3v。通过脉冲的周期设置下一个脉冲。根据第二部的数据设定时间窗。
第五步:发射两窜脉冲产生干扰波。测量过零时间与回波振幅。如果逆向发生在回波中,决定要不通过在低气压插入振幅。
第六步:通过公式计算距离y。
中原工学院毕业设计(论文)译文
4、超声波测距系统的软件设计
软件分为俩部分,主程序和中断服务程序。主程序完成初始化工作、各路超声波发射和接收顺序的控制。定时中断服务子程序完成三方向超声波的轮流发射,外部中断服务子程序主要完成时间值的读取、距离计算、结果的输出等工作。
中原工学院毕业设计(论文)译文
5、结论
对所要求测量范围30cm-200cm内的平面物体做了多次测量发现,其最大误差为1.5cm,且重复性好。可见基于单片机设计的超声波测距系统具有硬件结构简单、工作可靠、测量误差小等特点。因此,它不仅可用于移动机器人,还可以用在其他检测系统中。
思考:至于为什么不用接收管做放大电路,因为放大倍数搞不好,集成放大电路,还带自动电平增益控制,放大倍数为76db,中心频率是38k到40k,刚好是超声波传感器的谐振频率。
中原工学院毕业设计(论文)译文
参考文献
,J.D.,Khuri-Yakub, Kino,G.S.,“High
Frequency Acoustic Wave Measurement in Air”,in Proceedings
of IEEE 1983 Ultrasonic Symposium,October 31-2 November,1983,Atlanta,GA, Abreu,J.M.,Ceres, Freire,T.,“Ultrasonic Ranging: Envelope Analysis
Gives Improved Accuracy”,Sensor Review, Vol.12
No.1,1992,la, M., Anaya,J.J and Fritsch
C.,‖Digital Signal Processing Techniques for High Accuracy
Ultrasonic Range
and
Measurement:,IEEE
.40
Transactions:
No.4, August Instrumentation
1991,, C., Cicco, G.D., Mortem, B., Prudenziati,
M., and Taron, A., ―A Temperature Compensated Ultrasonic
Sensor Operating in Air for Distance and Proxinmity
Measurement‖, IEEE Trasaction on Industry Electronics, Vol, IE-29
No.4,1982, , J.M., Ceres, R., Calderon, L and
Freire, T., ‖Ultrasonic Ranging Gets Themal Correction‖, Sensor
Review, Vol, 9 No.3, 1989,pp.153-5.中原工学院毕业设计(论文)译文
Ultrasonic ranging system design Publication title: Sensor
rd:.13 ABSTRACT: Ultrasonic ranging
technology has wide using worth in many field, such as the
industrial locale, vehicle navigation and sonar
it has been used in level measurement, self-guided autonomous
vehicles, fieldwork robots automotive navigation, air and
underwater target detection, identification ,location and so
there is an important practicing meaning to learn the ranging
theory and ways improve the precision of the
ultrasonic ranging system in hand, satisfy the request of the
engineering personal for the precision,the bound and the usage,
a portable ultrasonic ranging system based on the single chip
processor was ds: Ultrasound r, Ranging
System, Single Chip Processor
uctive With the development of science and
technology, the improvement of people’s standard of living,
speeding up the development and construction of the
drainage system have greatly developed their situation is
constantly r, due to historical reasons many
unpredictable factors in the synthesis of her time, the city
drainage particular drainage system often lags behind
urban ore, there are often good building
excavation has been building facilities to upgrade the drainage
system brought to the city sewage, and it is clear
to the city sewage and drainage culvert in the sewage treatment
t is very important to people’s
robots designed to clear the drainage culvert and the automatic
control system Free sewage culvert clear guarantee robot, the
robot is designed to clear the culvert sewage to the l
System is the core component of the development of ultrasonic
range ore, it is very important to design a good
ultrasonic range finder.1.1 subject background
With the development of economy and car scientific and
technological progress, highway traffic presents driving fast pace,
traffic dense is changed and the driver not professional
the same time, along with the rapid development of auto
industry, automobile yield and quantities are increased
road development,中原工学院毕业设计(论文)译文
transportation management is relatively backward, leading
to a large number of traffic accidents in some cities, especially
igent transportation system in the world, ITS
transportation science and technology of advanced technology,
ITS exerting existing infrastructure of potential, enhance the
transport efficiency, safeguard traffic safety and ease traffic
wager plug, improving urban environment aspects of
outstanding performance, has received the governments of
widespread Chinese government is also highly
intelligent transportation system of the development and
popularization automotive anti-collision system
as ITS development of a base, ITS success to the whole system
has a very significant ionally, auto safety said can be
divided into two main research direction: first,it is active safety
technology, including the prevention of accidents, the way is now
automotive safety research ultimate purpose;second, it is passive
safety technique, namely the occupant protection after the
automotive safety field passive safety more
research, mainly from the airbag, ABS(antilock brakes)and
suspension from the aspects such as to ensure safety of
personnel the economic and safety two ways, these
passive safety measures is the accident of vehicle and personnel
moments protection, with great limitations, thus vehicle active
safety research is particularly important, leads to a of this study
is based on single chip ultrasonic ranging system is
a kind of can advance to the driver issued audio-visual speech
signal detection is installed in cars that can detect
trying to approach the body of a car pedestrians and vehicles or
around obstacles, Can send to the driver and crew imminent
danger ahead of the signal, prompting a crash drivers take
emergency measures to cope with special danger, avoid the
loss.1.2 question design significance
Along with the development of modern society
industrialization process, car this traffic tools are used for more
and more people, but any problem has obvious that along with
the increase in vehicles, traffic accident, which led to the frequent
occurrence of casualties and property losses number
highway traffic accident analysis showed that
more than 80% of the accident due to the driver reaction inferior
things, caused more than 65% of vehicle collision, the rest
belongs to tracing cauda collided belongs to the side
es-benz Automobile Company for all kinds of
traffic accident research shows that: if the driver can early 1S are
aware
中原工学院毕业设计(论文)译文
that a accident risk and take the appropriate corrective
measures, the overwhelming majority of traffic accidents can be
ore, vigorously research and development as the
automotive anti-collision device etc active car auxiliary safe
device, reduce the burden and misjudgments drivers to improve
the traffic safety will play an important sly, this kind
of product research and development has great realize meaning
and broad application prospects.1.3 Ultrasonic ranging in
automotive applications introduced
Ultrasonic back-draft rangefinder(known as electron
optics)automotive anti-collision reversing device, can safe
adjunct to sound or more intuitive digital form the dynamic
display of around earlier products is to use buzzer
alarm, hum more anxious, and says vehicles from obstructions
uent product can display the car from the body
after the obstacles of its products detection range
in 0.4 ~ 1.5 m, some product can achieve 0.35 ~ 2.5 m, and have
distance display, sound alarm, area-warning and azimuth
instructions, some products also has the boot self-checking
appeared on the market at present with voice alarm
function of products are the main problem is big,
alarm measuring blind area lags behind, without considering the
automobile braking inertial factors and make drivers brake lag,
the anti-interference ability is not strong, misstatement or
automotive anti-collision radar is able to realize
impact-proof alarm functions, basically have ultrasonic this
intangible ruler, it recently obstacles distance measurement, and
told to the ly ultrasonic range-finding principle
simple: it emit ultrasonic echo, and receive reflected by
microcontroller counter obtain both lag using formula S = t, Ct /
2 calculating distances, including S for cars and obstacles, C for
the distance between the sound wave propagation in the
medium paper introduces the ultrasonic ranging
system only have 2 ultrasonic transducer(known as
probe)respectively, decorate in cars left and right after after 2
e of detecting forward and reverse direction
obstacle distance, the rearview mirror built-in display element
display distance and direction, issued must be sound, plays the
role of hints and USES a STC89C52 SCM two way
ultrasonic signal cyclicly onic refers to the
20HHZ wave frequency is order to use the ultrasonic
detection means, must generate as ultrasonic wave and receiving
te the functions of the device is called the
中原工学院毕业设计(论文)译文
ultrasonic sensor, habit, ultrasonic transducer or ultrasonic
onic sensors have both transmitters and receivers,
but a ultrasonic sensors can also has the sending and receiving
the sound waves of the dual onic sensors is using the
principle of piezoelectric effect and ultrasonic energy conversion,
be in namely emit ultrasonic, energy conversion, launch
ultrasonic, And in the stockades, received echo ultrasonic
vibration into electrical onic ranging principle
generally USES the time method for the measured
ultrasonic from the launch to meet obstacles returns experience
of time, again multiply ultrasonic speed of get twice the distance
between the sound source and ing distance a
variety of ways, short can use ruler, long-range laser
displacement etc, are suitable for high accuracy of ultrasonic
ranging in long distance e of ultrasound in
standard air of propagation speed 331.45 meters per second, by
single-chip microcomputer is responsible for timing, SCM use
12.0 M crystals, so the system of measurement precision theory
can achieve mm e of ultrasonic directivity strong,
energy consumption is slow, in a medium transmission distance,
thus ultrasonic can be used for distance
ultrasonic detection distance, the design is more convenient,
computing procese also relatively simple, and the measurement
precision can also meet the onic generator
can be divided into two kinds: one kind is to use electrical means
producing ultrasonic, one kind is with mechanical approach to
producing design belongs to nearly distance
measurement, can use commonly used the piezoelectric
ultrasonic transducer to achieve trigger ultrasonic
ranging work, can according to measuring launch reflection wave
wave and the time interval between the measured distance, so as
to achieve the mainly have three ranging methods:
(1)phase assay, phase assays high precision, but detection
though limited range,(2)sound amplitude assay, acoustic
amplitude assay vulnerable reflection wave influence;
(3)ferrying more time assay, crossing the time assay way of
working is simple, intuitive, in hardware control and software
design are very easy to principle is: from the launch
emit ultrasonic detection sensor, the gas medium spread to
receive sensor of time, this time is crossing the more
design is the use of ultrasonic ranging the crossing the time
the mobile vehicles of the application 15
中原工学院毕业设计(论文)译文
of ultrasonic sensor is the use of ultrasound in air of
directional spread and solid reflective characteristics(p-wave)and
by receiving their launch ultrasonic reflecting signal, according to
the ultrasonic issued and echo receiving the Windows and
propagation speed, calculate transmission distance, thus obtains
the obstacles to vehicle distance.中原工学院毕业设计(论文)译文
2.A principle of ultrasonic distance measurement
2.1 the principle of piezoelectric ultrasonic generator
Piezoelectric ultrasonic generator is the use of piezoelectric
crystal resonators to onic generator, the internal
structure as shown, it has two piezoelectric chip and a resonance
it’s two plus pulse signal, the frequency equal to the
intrinsic piezoelectric oscillation frequency chip, the chip will
happen piezoelectric resonance, and promote the development
of plate vibration resonance, ultrasound is sely,
if the two are not inter-electrode voltage, when the board
received ultrasonic resonance, it will be for vibration suppression,
then it becomes the ultrasonic traditional way to
determine the moment of the echo’s arrival is based on
thresholding the received signal with a fixed
threshold is chosen well above the noise level, whereas the
moment of arrival of an echo is defined as the first moment the
echo signal surpasses that intensity of an echo
reflecting from an object strongly depends on the object’s
nature, size and distance from the r, the time
interval from the echo’s starting point to the moment when it
surpasses the threshold changes with the different intensities
arriving exactly at the same tome will surpass the threshold at
different stronger one will surpass the threshold
earlier than the weaker, so it will be considered as belonging to a
nearer object.2.2 The principle of ultrasonic distance
measurement Ultrasonic transmitter in a direction to launch
ultrasound, in the moment to launch the beginning of time at the
same time, the spread of ultrasound in the air, obstracles on his
way to return immediately, the ultrasonic reflected wave wave
received by the reveiver immediately stop the onic in
the air as the propagation velocity of 340m/s, according to the
timer records the time t, we can calculate the distance between
the launch distance barrier(s), that is:s=340t/2
中原工学院毕业设计(论文)译文
onic Ranging System for the Second Circuit Design
System is characterized by single-chip microcomputer to
control the use of ultrasonic transmitter and ultrasonic receiver
since the launch from time to time, single-chip selection of
8751,economic-to –use, and the chip has 4K of ROM, to facilitate
t schematic diagram shown in Figure
1 circuit principle diagram
中原工学院毕业设计(论文)译文
3.1 40 kHz ultrasonic pulse generated with the launch
Ranging system using the ultrasonic sensor of piezoelectric
sensors UCM40, its operating voltage of the pulse signal is 40kHz,
which by the single-chip implementation of the following
procedures to :mov 14h,# 12h;ultrasonic firing
continued 200ms here:cpl pl.0;output 40 kHz square wave
nop;
nop;nop;djnz 14h, here;ret Ranging in front of single-chip
termination circuit P1.0 input port, single chip implementation of
the above procedure, the P1.0 port in a 40kHz pulze output signal,
after amplification transistor T, the drive to launch the first
ultrasonic UCM40T, issued 40kHz ultrasonic pulse, and the
continued launch of g the right and the left side of
the circuit, respectively, then input port P1.1 and P1.2, the
working principle and circuit in front of the same location.3.2
Reception and processing of ultrasonic
Used to receive the first launch of the first pair UCM40R, the
ultrasonic pulse modulation signal into an alternating voltage,
the op-amp amplification IC1A and after polarization IC1B to
2 is locked loop with audio decoder chip LM567, internal
voltage-controlled oscillator center frequency of f0=1/1.1R8C3,
capacitor C4 determine their target bandwidth.R8-conditioning
in the launch of the carrier frequency on the LM567 input signal
is greater than 25Mv, the output from the high jump 8 feet into
a low-level, as interrupt request signals to the single-chip
g in front of single-chip termination circuit
port INT0 interrupt the highest priority, right or left location of
the output circuit with output gete IC3A access INT1 port single-chip, while single-chip P1.3 and P1.4 received input IC3A,
interrupted by the process to identify the source code is as
follows: receivel:
push psw
push ace
中原工学院毕业设计(论文)译文
cir ex1: related external interrupt 1
jnb p1.1, right;P1.1 pin to 0, ranging from right to interrupt
service rountine circuit
jnb p1.2, left;P1.2 pin to 0, to the left ranging circuit
interrupt service routine return:SETB EX1;open external
interrupt 1
pop
acc pop
psw reti right:…;right location entrance circuit interrupt
service rountine
Ajmp Return left:…;left Ranging entrance circuit interrupt
service rountine
Ajmp Return
3.3 The calculation of ultrasonic propagation time
When you start firing at the same time start the single-chip
circuitry within the timer T0, the use of timer counting function
records the time and the launch of ultrasonic reflected wave
received time when you receive the ultrasonic reflected wave, the
receiver circuit outputs a negative jump in the end of INT0 or
INT1 interrupt request generates a signal, single-chip
microcomputer in response to external interrupt request, the
implementation of the external interrupt service subroutine, read
the time difference, calculating the of its source is
as follows: RECEIVE0: PUSH PSW PUSH ACC CLR EX0;related
external interrupt 0 MOV R7, TH0;read the time value MOV R6,
TL0 CLR C MOV A, R6 SUBB A,#0BBH;calculate the tome
difference MOV 31H, A;storage results MOV A, R7 SUBB A,#3CH
中原工学院毕业设计(论文)译文
MOV 30H,A SETB EX0;open external interrupt 0 POP ACC
POP PAW RETI For a flat target, a distance measurement consists
of two phases: a coarse measurement and, a fine measurement:
Step 1: Transmission of one pulse train to produce a simple
ultrasonic
2: Changing the gain of both echo amplifiers
according to equation,until the echo is
3:detection of te amplitudes anf zero-crossing times of both
4:setting the gains of both echo amplifiers to
normalize the output at, say 3 g the period of the next
pulses according to the: period of g the time
window according to the data of step 5:sending two pulse
trains to produce an interfered g the zero-crossing in
the echo,detemine to otherwise calculate to by interpolation
using the amplitudes near the t sub ml and t sub
6: Calculation of the distance y using equation.中原工学院毕业设计(论文)译文
ultrasonic ranging system software design
Software is divided into two parts, the main program and
interrupt service tion of the work of the main
program is initialized, each sequence of ultrasonic transmitting
and receiving upt service routines from time to
complete three of the rotation direction of ultrasonic launch, the
main external interrupt service subroutine to resd the value of
completion time, distance calculation, the results of the output
and so on.中原工学院毕业设计(论文)译文
sions
Required measuring range of 30cm~200cm objects inside
the plane to do a number of measurements found that the
maximum error is 0.5cm, and good -chip
design can be seen on the ultrasonic ranging system has a
hardware structure is simple, reliable, small features such as
measurement ore, it can be used not only for mobile
robot can be used in other detection ts: As for
why the receiver do not have the transistor amplifier circuit,
because the magnification well, integrated amplifier, but also
with automatic gain control level, magnification to 76dB, the
center frequency is 38k to 40k, is exactly resonant ultrasonic
sensors frequency.中原工学院毕业设计(论文)译文
REFERENCES ,J.D.,Khuri-Yakub, Kino, G.S., ‖High
Frequency Acoustic Wave Measurement in Air‖, in Proceedings
of IEEE 1983 Ultrasonic Symposium, October 31-2 November,
1983, Atlanta, GA, Abreu,J.M.,Ceres,
Freire, T.,‖Ultrasonic Ranging: Envelope Analysis Gives Improved
Accuracy‖, Sensor Review, Vol.12No.1,1992, la,
M., Anaya,J.J and Fritsch C.,‖Digital Signal Processing Techniques
for High Accuracy Ultrasonic Range Measurement:,IEEE
Transactions: Instrumentation and .40 No.4,
August 1991,, C., Cicco, G.D., Mortem, B.,
Prudenziati, M., and Taron, A., ―A Temperature Compensated
Ultrasonic Sensor Operating in Air for Distance and Proxinmity
Measurement‖, IEEE Trasaction on Industry Electronics, Vol, IE-29
No.4,1982, , J.M., Ceres, R., Calderon, L and
Freire, T., ‖Ultrasonic Ranging Gets Themal Correction‖, Sensor
Review, Vol, 9 No.3, 1989,pp.153-5.24
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