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大学英语综合教程第四册 8

所属教程:大学英语综合教程第四册

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https://online2.tingclass.net/lesson/shi0529/0008/8625/8.mp3
https://image.tingclass.net/statics/js/2012
[00:00.00] Steve Shladover outlines the benefits to be gained from vehicles that could drive themselves
[00:06.71]and discusses how this could be achieved.
[00:10.61]INTELLIGENT VEHICLES by Steve Shladover
[00:15.33]Even when cars were still young,futurists began thinking about vehicles that could drive themselves,without human help
[00:24.79]Perhaps the best known of these conjectures was the General Motors Futurama,the hit of the1939 New York World's Fair
[00:35.40]Now,at the start of the new century,it's worth taking a fresh look at this concept and asking
[00:42.92]how automation mingt change transportation and the quality of our lives.
[00:49.50]Consider some of the implications of cars that could drive themselves.
[00:54.83]We might eliminate the more than ninety percent of traffic crashes
[01:05.02]that are caused by human errors such as misjudgments and inattention.
[01:10.92]We might reduce antisocial driving behavior such as road rage,thereby singnificantly reducing the stress of driving.
[01:20.61]The entire population,including the young,the old,and the infirm,
[01:26.70]might enjoy a higher level of mobility without requiring advanced driving skills.
[01:33.91]The luxury of being chauffeured to your destination might be enjoyed by all,not just the wealthiest individuals.
[01:42.82]Fuel consumption and pollution might be reduced by smoothing traffic flow
[01:49.45]and running vehicles close enough to each other to benefit from aerodynamicdrafting.
[01:56.48]Traffic-management decisions might be based on firm knowledge of vehicle responses to instructions,
[02:03.79]rather than on guesses about the choices that drivers might make.
[02:09.04]The capacity of a freeway lane might be doubled or tripled,making it possibe to accommodate growing demands for travel
[02:18.00]without major new construction,or,equivalently,today's level of congestion mingt be reduced,enabling travelers to save time
[02:28.43]Is it feasible?
[02:30.96]This is now a realisitic prospect.With advances in technology
[02:36.00]we can readily visualize your trip on an automated highway system.
[02:41.67]Imagine leaving work at the end of the day and needing to drive only
[02:47.05]as far as the nearest on-ramp to the local automated highway.At the onramp,
[02:54.94]you press a button on your dashboard to select the off-ramp closest to your home and then relax
[03:02.94]as your car's electronic systems,in cooperation with roadside electronics and similar systems on other cars,
[03:11.76]guide your car smoothly,safely,and effortless toward your destiantion.
[03:18.69]En route you save time by maintaining full speed even at rush-hour traffic volumes.
[03:25.82]At the end of the off-ramp you resume normal control and drive the remaining distance of your home
[03:32.90]better rested and less stressed than if you had driven the entire way.
[03:38.93]Although many different technical developments are necessary to turn this image into reality,none requires exotic technologies
[03:48.52]and all can be based on systems and components
[03:52.99]that are already being actively developed in the international motor vehicle industry.
[03:59.60]These could be viewed as replacements for the diverse functions that drivers perform every day:obserbving the road
[04:08.01]observing the preceding vehicles,steering,accelerating,braking,and deciding when and where to change course.
[04:16.78]Observing the road
[04:19.66]Researches have developed a road-reference and sensing system
[04:24.65]that makes it possible to determine accurately a vehicle's position and orientation relative to the lane's center.
[04:33.19]Cheap permanent magnets are buried at four-foot intervals along the lane centerline
[04:40.22]and detected by magnetometers mounted under the vehicle's bumpers.These meters prvide the information
[04:49.23]used by the vehicle's control computer to determine its exact position of the vehicle.
[04:56.57]Other researchers have used computer vision systems to observe the road.These are vulnerable to weather problems
[05:05.37]and provide less accurate measurements,but they do not require special roadway installations.
[05:12.66]other than well-maintained lane markings.
[05:16.84]Observing preceding vehicles
[05:20.39]The distances and closing rates to preceding vehicles can be measured by a radar or a laser rangefinder.
[05:29.14]Both technologies have already been implemented in commercially available systems in Japan and Europe
[05:36.82]The laser systems are currently less expensive,
[05:40.27]but the radar systems are more effective at detecting dirty vehicles and operating in adverse weather conditions
[05:49.41]As productins volumes increase and unit costs decrease, the radars are likely to find increasing favor.
[05:57.77]Steering,accelerating and brading
[06:02.03]The equivalents of these driver muscle functions are electromechanical devices installed in the automated vihicle
[06:10.42]They receive electronic commands from the onboard control computer
[06:14.91]and then apply the appropriate steering angle,throttle angle,and brakd
[06:21.10]pressure by means of small electricmotorsEarly versions of these devices are alresdy being introduced int production vehicles
[06:32.62]where they receive their commans directly from the driver's inputs to the steering whessl and pedals.
[06:39.54]These decisions ate being made for reasons largely unrelated to automation.
[06:44.66]Rather they are associated with reduced energy consumption,
[06:49.99]simplification of vehicle design,enhanced ease of vehicle assembly,
[06:55.32]improved ability to nadjust performance to match driver perferences,
[07:00.96]and cost savings compatred to traditional direct mechanical comtrol devies.
[07:07.68]Deciding when and where to change course
[07:11.83]Computers in the vehicles and those at the roadside have different functions.
[07:17.13]Roadside computer are computers are better suited for traffic management,
[07:22.02]setting the target speed for each segment and lane of roadway,
[07:26.09]and allocating vehicles to different lanes of a multilane automated facility.
[07:32.18]The aim is to maintain balanced flow among the lanes and to avvoed obstacles or incidents tha might block alane.
[07:40.70]The vihicle's onboard computers are better suited to handling decisions about exactly
[07:47.72]when and where to change lanes to avoed inerference with other vehicles.
[07:54.23]Remaining challenges
[07:57.15]There remain a number of difficulties t be over come.These are mainly technical,
[08:03.32]but there are in addition a number of nontechnical challenges that need to be addressed.
[08:09.87]These involve issues of liability,costs,and perceptions.
[08:15.28]Automated control of vehicles shifts liability for most crashes from the individual driver(and his or her insurance company
[08:25.03]to the designer,developer,and vendor of the vehicle and roadway control systems.Provided the system is indeed safer
[08:34.25]than today's driver-vehicle-highway system,overall exposure should be reduced .But its costs will be shifted
[08:44.51]from automovile insurance premiums to the purchase or lease price of the automated vehicle
[08:51.59]and toll for use of the automated highway facility.
[08:56.27]All new techologies tend to be costly when they first become available in small quntities,
[09:02.98]then their costs decline as production volumes increase and the technologies mature.
[09:09.12]We should expect vehicle automation technologies to follow the same pattern.
[09:14.92]They may initially be economically viable only for heavy vehicles(transit buses,commercial trucks)and highend passenger cars
[09:24.64](2)However,it should not take long for the costs to become affordable to a wide range of vehicle owners and operators,
[09:33.34]especially with many of the enabling technologies already being commercialized for volume production today.
[09:41.59](3)The largest impediment to introduction of electronic chauffeuring may turn out be the general perception that
[09:49.77]it's more difficult and expensive to implement than it really is.
[09:54.55]If political and imdustrial decision maders perceive automated driving to be too futuristec,
[10:01.91]they will not pay it the attention it deserves and will not invest their resources toward acceleerating its deployment.
[10:10.48]The perception could thus become a self-fulfilling prophecy.
[10:15.24]It is important to recognize that automated vehicles are already carrying millions of passengers every day.
[10:23.07]Most major airports have automated people movers that transfer passengers among terminal buildings.
[10:30.49]Urban transit lines in Paris,London,Vancouver,
[10:35.98]Lyon,and Lille,among others,are operating with completely automated,driverless vehicles;
[10:43.16]some have been doing so for more than a decade.
[10:46.97]Modern commercial aircraft operate on autopilot for much of the time,
[10:52.85]and they also land under automatic comtrol at suitably equipped airports on regular basis.
[11:00.40](4)Given all of this experience in implemaenting safe automated transportation systemsm,it is not such a large leap
[11:09.10]to develop road vehicles that can operate under automatic control.That should be a realistic goal for the next decade.
[11:18.14]The transportation system will thus gain substantial benefits from the revolution in information techonlogy.
[11:26.55]outline at the start of implication thereby
[11:30.99]概述 在……开始时 暗示 从而
[11:35.43]feasible realistic in cooperation with en route
[11:40.77]有理的 实际的 与……合作 在途中
[11:46.12]component civerse permanent implement
[11:51.17]部件 多种多样的 永久的 实施
[11:56.23]equlvalent appropriate by means of assembly
[12:01.45]相等物 适当的 依靠 组装
[12:11.35]暴露 长成 引进 认为
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