交通信號(hào)研究外文文獻(xiàn)翻譯中英文

1、交通信號(hào)研究外文文獻(xiàn)翻譯 (含：英文原文及中文譯文) 文獻(xiàn)出處： vehicular technology ieee transactions on, 2012, 3(1):8-16.英文原文 traffic signalsroozemond jeanin the united states alone ,some 250,000 intersections have traffic signals , which are defined as all power-operated traffic-control devices except flashers, signs , and mar

2、kings for directing or warning motorists, cyclists, or pedestrians.signals for vehicular , bicycle , and pedestrian control are pretimed where specific times intervals are allocated to the various traffic movements and as traffic actuated where time intervals are controlled in whole or in part by tr

3、affic demand.pretimed traffic signalspretimed traffic signals are set to repeat regularly a given sequence of signal indications for stipulated time intervals through the 24-hr day. they have the advantages of having controllors of lower first cost and that they can be interconnected and coordinated

4、 to vehicles to move through a series of intersections with a minimum of stops and other delays.also, their operation is unaffected by conditions brought on by unusual vehicle behavior such as forced stops, which , with some traffic-actuated signal installations may bring a traffic jam. their disadv

5、antage is that they cannot adjust to short-time variations in traffic flow and often hold vehicles from one direction when there is no traffic in the other. this results in inconvenience, and sometimes a decrease in capacity. cycle length the time required for a complete sequence of indications, ord

6、inarily falls between 30 and 120s. short cycle lengths are to be preferred, as the delay to standing vehicles is reduced. with short cycles, however a relatively high percentage of the total time is consumed in clearing the intersection and starting each succeeding movement. as cycle length increase

7、s, the percentage of time lost from these causes decreases. with high volumes of traffic, it may be necessary to increase the cycle length to gain added capacity.each traffic lane of a normal signalized intersection can pass roughly one vehicle each 2.1s of green light. the yellow (caution) interval

8、 following each green period is usually between 3 and 6s, depending on street width, the needs of pedestrians, and vehicle approach speed. to determine an approximate cycle division, it is common practice to make short traffic counts during the peak period. simple computations give the number of veh

9、icles to be accommodated during each signal indication and the minimum green time required to pass them. with modern control equipment, it is possible to change the cycle length and division several times a day, or go to flashing indications to fit the traffic pattern better.at many intersections, s

10、ignals must be timed to accommodate pedestrian movements. the manual recommends that the minimum total time allowed be an initial interval of 4 to 7s for pedestrians to start plus walking time computed at 4 ft/s (1. 2m/s). with separate pedestrian indicators, the walk indication(lunar white) covers

11、the first of these intervals, and flashing dont walk (portland orange ) the remainder. the walk signal flashes when there are possible conflicts with vehicles and is steady when there are none. steady dont walk tells the pedestrian not to proceed.if pedestrian control is solely by the vehicle signal

12、s, problems develop if the intersection is wide, since the yellow clearance interval will have to be considerably longer than the 3 to 5s needed by vehicles. this will reduce intersection capacity and may call for a longer cycle time. on wide streets having a median at least 6 ft (1. 8m)wide, pedest

13、rians may be stopped there. a separate pedestrian signal activator must be placed on this median if pedestrian push buttons are incorporated into the overall control system.coordinated movementfixed-time traffic signals along a street or within an area usually are coordinated to permit compact group

14、s of vehicles called platoons to move along together without stopping. under normal traffic volumes, properly coordinated signals at intervals variously estimated from 2500 ft (0. 76km)to more than a mile (1. 6km) are very effective in producing a smooth flow of traffic. on the other hand, when a st

15、reet is loaded to capacity, coordination of signals is generally ineffective in producing smooth traffic flow.four systems of coordination-simultaneous, alternate, limited progressive, and flexible progressive-have developed over time. the simultaneous system made all color indications on a given st

16、reet alike at the same time .it produced high vehicle speeds between stops but low overall speed. because of this and other faults, it is seldom used today.the alternate system has all signals change their indication at the same time, but adjacent signals or adjacent groups of signals on a given str

17、eet show opposite colors. the alternate system works fairly well on a single street that has approximately equal block spacing. it also has been effective for controlling traffic in business districts several blocks on a said, but only when block lengths are approximately equal in both directions. w

18、ith an areawide alternate system , green and red indications must be of approximately equal length. this cycle division is satisfactory where two major streets intersect but gives too much green time to minor streets crossing major arteries. other criticisms are that at heavy traffic volumes the lat

19、er section of the platoon of vehicles is forced to make additional stops, and that adjustments to changing traffic conditions are difficult.the simple progressive system retains a common cycle length but provides go indications separately at each intersection to match traffic progression. this permi

20、ts continuous or nearly continuous flow of vehicle groups at a planned speed in at least one direction and discourages speeding between signals. flashing lights may be substituted for normal signal indications when traffic becomes light.the flexible progressive system has a master controller mechani

21、sm that directs the controllers for the individual signals. this arrangement not only gives positive coordination between signals , but also makes predetermined changes in cycle length , cycle split , and offsets at intervals during the day. for example, the cycle length of the entire system can be

22、lengthened at peak hours to increase capacity and shortened at other times to decrease delays. flashing indications can be substituted when normal signal control is not needed. also the offsets in the timing of successive signals can be adjusted to favor heavy traffic movements, such as inbound in t

23、he morning and outbound in the evening. again, changes in cycle division at particular intersections can be made. the traffic responsive system is an advanced flexible progressive system with the capacity to adjust signal settings to measured traffic volumes.where traffic on heavy-volume or high-spe

24、ed arteries must be interrupted for relatively light cross traffic, semi-traffic-actuated signals are sometimes used. for them, detectors are placed only on the minor street. the signal indication normally is green on the main road and red on the cross street. on actuation, the indications are rever

25、sed for an appropriate interval after which they return to the original colors.the quality of urban traffic control systems is determined by the match between the control schema and the actual traffic patterns. if traffic patterns change what they usually do the effectiveness is determined by the wa

26、y in which the system adapts to these changes. when this ability to adapt becomes an integral part of the traffic control unit it can react better to changes in traffic conditions. adjusting traffic control unit is a costly and timely affair if it involves human attention. the hypothesis is that it

27、might offer additional benefit using self-evaluating and self-adjusting traffic control systems. there is already a market for an urban traffic control system that is able to react if the environment changes the so called adaptive systems. quot racquet adaptive systems will need pro-active calculate

28、d traffic information and cycle plans- based on these calculated traffic conditions- to be updated frequently. our research of the usability of agent technology within traffic control can be split into two parts. first there is a theoretical part integrating agent technology and traffic control. the

29、 final stage of this research focuses on practical issues like implementation and performance. here we present the concepts of agent technology applied to dynamic traffic control. currently we are designing a layered model of an agent based urban traffic control system. we will elaborate on that in

30、the last chapters.these agents have the task of solving conflicts between lower level agents that they cant solve. this represents current traffic control implementations and ideas. one final aspect to be mentioned is the robustness of agent based systems if all communication fails the agent runs on

31、 if the agent fails a fixed program can be executed. to be able to keep our first urban traffic control model as simple as possible weave made the following assumptions: we limit ourselves to inner city traffic control road segments intersections corridors we handle only controlled intersections wit

32、h detectors intensity and speed at all road segments we only handle cars and we use simple rule bases for knowledge representation. types of agents in urban intersection control as we divide the system in several recognizable parts we define the following 4types of agents:- roads are represented by

33、special road segment agents rsa- controlled intersections are represented by intersection agents itsa- for specific defined areas there is an area agent higher level- for specific routes there can be route agents that spans several adjoining road segments higher level. we have not chosen for one age

34、nt per signal. this may result in a more simple solution but available traffic control programs do not fit in that kind of agent. we deliberately choose a more complex agent to be able to use standard traffic control design algorithms and programs. the idea still is the optimization on a local level

35、 intersection but with local and global control. therefore we use area agents and route agents. all communication takes place between neighboring agents and upper and lower level ones. design of our agent based system the essence of a demand responsive and pro-active agent based utc consists of seve

36、ral itsas intersection agent. some authority agents area and route agents and optional road segment agents rsa. the itsa makes decisions on how to control its intersection based on its goals capability knowledge perception and data. when necessary an agent can request for additional information or r

37、eceive other goals or orders from its authority agents. for a specific itsa implemented to serve as an urban traffic control agent the following actions are incorporated rosemont 1998:- data collection / distribution via rsa - information on the current state of traffic from / to other itsas - on ot

38、her adjoining signalized intersections- analysis with an accurate model of the surrounds and knowing the traffic and traffic control rules define current trend detect current traffic problems- calculation calculate the next optimal cycle mathematically correct- decision making with other agent decid

39、ing what to use for next cycle handle current traffic problems- control operate the signals according to cycle plan. in figure 1 a more specific example of a simplified agent based utc system is given. here we have a route agent controlling several intersection agents which in turn manage their inte

40、rsection controls helped by rsas. the itsa is the agent that controls and operates one specific intersection of which it is completely informed. allits as have direct communication with neighboring itsas rsas and all its traffic lights. here we use the agent technology to implement a distributed pla

41、nning algorithm.中文譯文交通信號(hào)研究作者：roozemond jean僅在美國(guó)，大約有25萬(wàn)個(gè)十字路口設(shè)有交通信號(hào)燈，交通信號(hào)燈定義為除了閃光燈，標(biāo)志和指示或警告駕駛者，騎自行車者或行人的標(biāo)志之外的所有動(dòng)力操作交通控制設(shè)備。用于車輛，自行車和行人控制的信號(hào)是“預(yù)先計(jì)劃好的”，其中特定的時(shí)間間隔分配給各種交通流動(dòng)，并且作為“交通啟動(dòng)”，其中時(shí)間間隔全部或部分由交通需求控制。預(yù)先制定的交通信號(hào)“預(yù)定”交通信號(hào)設(shè)置為在24小時(shí)的日期內(nèi)按規(guī)定的時(shí)間間隔定期重復(fù)給定的信號(hào)指示序列。它們具有控制成本較低的優(yōu)點(diǎn)，并且可以與車輛相互聯(lián)系和協(xié)調(diào)，以最少的停車時(shí)間和其他延遲通過(guò)一系列交叉路口。此外

42、，它們的運(yùn)行不會(huì)受到異常車輛行為（如強(qiáng)制停車）帶來(lái)的情況的影響，這些情況下，一些交通驅(qū)動(dòng)的信號(hào)裝置可能會(huì)造成交通堵塞。他們的缺點(diǎn)是他們無(wú)法適應(yīng)短時(shí)間的交通流量變化，并且通常在另一個(gè)方向沒(méi)有交通時(shí)從一個(gè)方向控制車輛。這導(dǎo)致不便，并且有時(shí)會(huì)降低容量?！爸芷陂L(zhǎng)度”是指示完整順序所需的時(shí)間，通常在30到120秒之間。較短的循環(huán)長(zhǎng)度是優(yōu)選的，因?yàn)檠舆t站立的車輛減少。在周期較短的情況下，相對(duì)較高的總時(shí)間百分比用于清除交叉點(diǎn)并開始每個(gè)后續(xù)運(yùn)動(dòng)。隨著周期長(zhǎng)度的增加，由這些原因造成的時(shí)間損失百分比下降。由于流量大，可能需要增加周期以增加容量。正常信號(hào)交叉口的每個(gè)車道可以通過(guò)大約一個(gè)車輛，每個(gè)2.1s的綠燈。每個(gè)

43、綠色周期后的黃色（警示）間隔通常在3到6秒之間，取決于街道寬度，行人需求和車輛接近速度。為了確定一個(gè)近似的周期劃分，通常的做法是在高峰期進(jìn)行短時(shí)間的流量統(tǒng)計(jì)。簡(jiǎn)單的計(jì)算給出了在每個(gè)信號(hào)指示期間要容納的車輛數(shù)量以及通過(guò)它們所需的最短綠色時(shí)間。使用現(xiàn)代化的控制設(shè)備，可以每天更改幾次循環(huán)長(zhǎng)度和分區(qū)，或者更快地閃爍以適應(yīng)交通模式。在許多交叉路口，信號(hào)必須定時(shí)以適應(yīng)行人的移動(dòng)。 “手冊(cè)”建議允許的最短總時(shí)間為行人開始加步行時(shí)間的初始間隔為4至7秒，計(jì)算時(shí)間為4英尺/秒（1.2米/秒）。通過(guò)獨(dú)立的行人指示燈，walk指示（月亮白色）涵蓋了這些間隔中的第一個(gè)，其余部分閃爍著不要行動(dòng)（波特蘭橙色）。 walk

44、信號(hào)在與車輛可能發(fā)生沖突時(shí)閃爍，沒(méi)有時(shí)會(huì)穩(wěn)定。堅(jiān)定不要行動(dòng)告訴行人不要進(jìn)行。如果行人控制完全依靠車輛信號(hào)，那么如果交叉路口較寬，則會(huì)出現(xiàn)問(wèn)題，因?yàn)辄S色間隙必須比車輛需要的3-5秒長(zhǎng)得多。這將減少路口通行能力，并可能需要更長(zhǎng)的周期時(shí)間。在中間寬度至少為6英尺（1.8米）的寬闊街道上，行人可能會(huì)停在那里。如果在整個(gè)控制系統(tǒng)中集成了行人按鈕，則必須在這個(gè)中間位置放置一個(gè)單獨(dú)的行人信號(hào)激勵(lì)器。協(xié)調(diào)運(yùn)動(dòng)沿著街道或區(qū)域內(nèi)的固定時(shí)間交通信號(hào)通常會(huì)進(jìn)行協(xié)調(diào)，以允許稱為“排”的緊湊型車輛在不停車的情況下一起移動(dòng)。在正常交通量的情況下，以2500英尺（0.76公里）至超過(guò)1.6英里（1.6公里）的各種間隔進(jìn)行適當(dāng)

45、的協(xié)調(diào)信號(hào)對(duì)于產(chǎn)生平穩(wěn)的交通流量非常有效。另一方面，當(dāng)一條街道滿負(fù)荷運(yùn)轉(zhuǎn)時(shí)，信號(hào)的協(xié)調(diào)一般無(wú)法有效地產(chǎn)生暢通的交通流量。隨著時(shí)間的推移，四種系統(tǒng)的協(xié)調(diào) - 同步，交替，有限的漸進(jìn)式和靈活的漸進(jìn) - 已經(jīng)發(fā)展起來(lái)。同步系統(tǒng)同時(shí)在給定的街道上進(jìn)行了所有顏色指示。它在停車間產(chǎn)生了較高的車速，但整體速度較低。由于這個(gè)和其他故障，它今天很少使用。備用系統(tǒng)的所有信號(hào)同時(shí)改變其指示，但是在給定街道上的相鄰信號(hào)或相鄰信號(hào)組顯示相反的顏色。在具有大致相等的塊間距的單個(gè)街道上，替代系統(tǒng)工作得很好。它也有效地控制了商業(yè)區(qū)的交通量，但只有在兩個(gè)方向上的路段長(zhǎng)度大致相等時(shí)才是如此。在區(qū)域范圍內(nèi)的替代系統(tǒng)中，綠色和紅色指

46、示必須大致相等。在兩條主要街道交叉的地方，這種周期劃分是令人滿意的，但是對(duì)于通過(guò)主要?jiǎng)用}的小街道來(lái)說(shuō)，這種周期劃分的時(shí)間太長(zhǎng)。其他批評(píng)指出，在交通繁忙的情況下，后排排隊(duì)車輛將被迫增加停車位，并且對(duì)交通狀況變化的調(diào)整很困難。簡(jiǎn)單的漸進(jìn)式系統(tǒng)保留了一個(gè)通用的周期長(zhǎng)度，但在每個(gè)路口分別提供“走”指示以匹配交通流量。這允許車輛組在至少一個(gè)方向上以計(jì)劃速度連續(xù)或幾乎連續(xù)地流動(dòng)，并且阻止信號(hào)之間的超速。當(dāng)交通變淺時(shí)，閃爍的燈可能代替正常的信號(hào)指示。靈活的漸進(jìn)式系統(tǒng)具有一個(gè)主控制器機(jī)制，可以將控制器指向各個(gè)信號(hào)。這種布置不僅給出了信號(hào)之間的正向協(xié)調(diào)，而且還在一天中的間隔中對(duì)周期長(zhǎng)度，周期分割和偏移進(jìn)行了預(yù)定的改變。例如，整個(gè)系統(tǒng)的周期長(zhǎng)度可以在高峰時(shí)間延長(zhǎng)以增加容量并在其他時(shí)間縮短以減少延遲。當(dāng)不需要正常信號(hào)控制時(shí)，閃爍指示可被替代。此外，可以調(diào)整連續(xù)信號(hào)的時(shí)間偏移以支持繁忙的交通運(yùn)動(dòng)，例如早上入站和晚上出站。再次，可以對(duì)特定交叉點(diǎn)處的周期劃分進(jìn)行改變。交通響應(yīng)系統(tǒng)是一個(gè)先進(jìn)的靈活的漸進(jìn)式系統(tǒng)