NAVIGATION AIDS AND IVHS
`
`29.7
`
`FIGURE29.3 Nodes and street segments of vector encoded map.
`
`By considering each road or street as a series of straight lines and each intersection as a node,
`a map may be viewedasaset ofinterrelated nodes,lines, and enclosed areasas illustrated by
`Fig. 29.3.
`Nodes may beidentified by their coordinates (e.g., latitude and longitude). Additional
`nodes“shape points” are positioned along curves where the link between two intersectionsis
`not a straight line. Curves are thus approximated by a series of vectors connecting shape
`points, whereasa single vector directly connects the node points representing successive inter-
`sections if there are no curves in the connecting road segment.
`The X-Y coordinates of node points may be encoded from mapsor aerial photographs.
`Theclassic approach uses special work stations which record the coordinates of a given point
`when the cross hair of an instrumentis placed over the point and a button pressed. This pro-
`cess has been automated in varying degrees. In some cases, the printed map is scanned to
`obtain a matrix image, which is then converted to vector form by software.
`Various combinationsof attributes associated with the encoded road networkare included
`in digital map databases. Of particular importance are roadwayclassifications, street names,
`and address ranges between nodes. Map databases used with systems that give turn-by-turn
`route guidance also require traffic attributes such as turn restrictions by time of day and
`delineation of one-way streets. Directory and yellow pages information for selecting attrac-
`tions, parking, restaurants, hotels, emergencyfacilities, etc., are commonly included.
`
`29.2.4 Map Matching
`
`Map matchingis a typeof artificial intelligence process used in virtually all vehicle navigation
`and route guidance systems that recognize a vehicle’s location by matching the pattern ofits
`apparent path (as approximated by dead reckoning and/or radiopositioning) with the road
`patterns of digital maps stored in computer memory. Most map-matching software may be
`classified as either semideterministic or probabilistic.‘
`
`641
`641
`
`

`

`29.8
`
`EMERGING TECHNOLOGIES
`
`Semideterministic. This approach assumesthat the equipped vehicle is essentially confined
`to a defined route or road network, andis designed to determine wherethe vehicle is along a
`route or within the road network. The concept maybeillustrated by tracking the location of a
`vehicle over the simple route shownin Fig. 29.4a which defines a route from node A through
`nodesB, C, D, E and thence back to A in termsof instantaneous direction (0) of travel versus
`cumulative distance (L) from the beginning as shown in Fig. 29.4b. Locations of nodes where
`direction changes occur (or could occur) are thus defined in terms of distance L. The solid line
`gives heading versus distance corresponding to the simple route. Alternative routes emanat-
`
`ing from each nodeare indicated by dashedlines.
`
`FIGURE29.4 Simplified route and vector model.‘
`
`Figure 29.5 shows the kernel of a semideterministic algorithm in highly simplified form.
`Onceinitialized at a starting location (@ = 90° and L =0 at Node A in the example), the algo-
`rithm, in effect, repeatedly asks, “Is the vehicle still on the route?” and “Whatis the present
`location along the route?” The vehicle is confirmed on the route if certain tests are satisfied.
`The location along the route is estimated by odometry, and error in the estimate is automati-
`cally removed at each node whereit is determined that an expected change in heading actu-
`ally occurs.
`
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`
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`

`NAVIGATION AIDS AND IVHS
`
`29.9
`
`
`RIGHT
`LEFT
`
`WHEEL
`WHEEL
`
`INTERRUPT
`
`
`EXIT TO
`
`
`ERROR
`
`
`ROUTINE
`
`
`EXIT To
`ERROR
`ROUTINE
`
`
`
`TURN
`$
`
`
`
`WITHIN
`MIDPOINT
`
`
`
`INTERRUPT
`
`
`
`
` RETURN TO PRIOR ROUTINE
`
`SET L TO
`MIDPOINT
`
`INITIALIZE
`NEXT
`VECTOR
`
`FIGURE29.5 Simplified map-matchingalgorithm.*
`
`The map-matching algorithm is driven by interrupts from differential odometer sensors
`installed on left and right wheels. The distance L from the beginning of a route segmentis
`updated by adding an increment AL for each left wheel interrupt, and the vehicle heading 6 is
`updated by adding an increment Ad calculated from the difference in travel by the left and
`right wheels since the count N waslast set to 0, As explained below, the N counter controls
`monitoring for unexpected heading changes occurring overrelatively short distances.
`Unless the turn flag is set to denote that the vehicle is approaching a distance L where a
`heading change should occur, count N is checked after each interrupt to determineif it has
`reached a limit C corresponding to an arbitrary amount of travel on the order of several
`meters. When the count limit C is reached, a test is made to determine if
`is within arbitrary
`limits (say +5 degrees to allow for lane changes, slight road curvature,etc.). If so, 6 is reset to
`oo (the direction of the vector being traveled) andNis set to 0 to start another cycle of moni-
`toring for unexpected heading changes.
`In addition to verifying that the vehicle stays on the route between nodes, this process
`removes error in measured vehicle heading that accumulates while 0<N<C. If the preceding
`test finds @ to be outside the limits, the vehicle is presumed to have turned off the route (per-
`haps into an unmapped driveway or parking lot) and other routines are called into play. For
`example, route recovery instructions could be issued.
`When the vehicle approaches within an arbitrary distance (e.g.,75 m) of a node where a
`change in vehicle heading should occur, the turn flag is set and a route guidance instructionis
`issued, giving the direction of the turn and,if appropriate, the name of the next road. The algo-
`rithm then monitors for changes in @ to confirm that the midpoint of the expected turn is
`reached within an arbitrary limit (e.g., 10 m) of the value of L specified for the node, and after-
`wards to confirm that the turn is completed.
`
`643
`643
`
`

`

`29.10
`
`EMERGING TECHNOLOGIES
`
`Upon reaching the midpoint, the current value of L is adjusted to that specified, thus
`removing any error in the measured distance accumulatedsince the last turn. If the expected
`turn is not confirmed within the allowed limits on distance L, the vehicle is assumed to have
`missed the turn or to have taken an alternate turn (see dashedlines in Fig. 29.4b) and other
`routines may becalled to identify the alternate route taken from the node.
`The semideterministic algorithm concept outlined here may be extended to tracking a
`vehicle’s location as it moves over arbitrary routes within a road network rather than follow-
`ing a preplanned route. As long as the vehicle stays on roadways defined by a vector-encoded
`digital map, the vehicle must exit each node via some vector. Thus, a map-matching algorithm
`can identify successive vectors traveled by measuring the direction of vehicle travel as it
`leaves each node and comparing the vehicle direction with that of various vectors emanating
`from the node.
`
`Probabilistic. An enhanced type of map-matching algorithm is required for tracking vehi-
`cles not presumedto be constrained to the roads. When the vehicle departs from the defined
`route or road network(e.g., into a parking lot), or appears to depart as a result of dead-reck-
`oning error, the routine repeatedly compares the vehicle’s dead-reckoned coordinates with
`those of the links surrounding the off-road area which encompasses the vehicle location in
`order to recognize where the vehicle returns to the road network. Unlike while traveling on
`defined roadways, map-matching adjustments do not prevent accumulation of dead-reckon-
`ing error. Thus, depending upon the distance traveled off road and the accuracy of the dead-
`reckoning sensors, there may be considerable uncertainty in vehicle coordinates, which could
`produce misleading conclusions whentested against the surrounding links.
`Probabilistic map-matching algorithms minimize the potential of off-road errors by main-
`taining a running estimate of uncertainty in dead-reckoned location, which is considered in
`determining whetherthe vehicle is on a street. The estimate of location uncertainty is reduced
`each timeit is deemedthat the vehicle is on a street, but the uncertainty resumes growthin pro-
`portion to further vehicle travel until the next match occurs. Thus, a probabilistic algorithm
`repeatedly asks, “Whereis the vehicle?,” with no a priori presumptionthatit is on a road.
`
`29.3 EXAMPLES OF NAVIGATION SYSTEMS
`
`Figure 29.6 is a block diagram showing the major elements of a typical automobile navigation
`system. Distance and heading (or heading change) sensors are almost invariably included for
`dead-reckoning calculations which, in combination with map matching, form the basic plat-
`form for keeping track of vehicle location. However, dead reckoning with map matching has
`the drawback of occasionally failing due to dead-reckoning anomalies, extensive travel off
`mapped roads,ferry crossings, etc.
`The location sensor indicated by dashedlines in Fig. 29.6 is an optional meansof providing
`absolute location to avoid occasional manualreinitialization when dead reckoning with map
`matching fails. Although proximity beacons serve to update vehicle location in a few systems
`(particularly those that also use proximity beacons for data communication), most state-of-
`the-art systems use GPSreceivers instead.
`The recent evolution and present trends of automobile navigation and route guidancesys-
`temsare illustrated by the following examples.
`
`29.3.1 Etak Navigator™/Bosch Traveipilot™
`
`The Etak, Inc. Navigator™ introduced in California in the mid-1980s was the first commercially
`available automobile navigation system to include digitized road maps, dead reckoning with
`
`644
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`

`NAVIGATION AIDS AND IVHS
`
`29.11
`
`LOCATION
`77 SENSOR
`|
`| i|
`
`||
`
`iene
`a |
`|
`
`DATA
`
`
`DISTANCE
`HEADING
`SENSOR
`SENSOR
`
`MAP DATA
`BASE
`
`NAVIGATION
`COMPUTER
`
`
`
`
` VISUAL
`
`OUTPUT
`
`
`FIGURE29.6 Typical components and subsystems of vehicle navigation system.
`
`map matching, and an electronic map display. It used a flux-gate compass and differential
`odometer for dead reckoning. The equivalent of two printed city street maps were vector
`encoded and stored on 3.5-Mb digital cassettes for map matching and display purposes.
`Although sales were modest, the highly publicized Etak Navigator drew widespread attention
`to the conceptof an electronic map display with icons showing currentlocation and destination.
`The Travelpilot, which is essentially a second generation of the Navigator, was jointly
`designed by Etak, Inc. and Bosch GmbH.? It was introduced in Germany in 1989 andin the
`United States two years later. One of the most conspicuous enhancements was the use of CD-
`ROMstorage for digitized maps. The 640-Mbcapacity permits the entire map of some coun-
`tries to be stored on a single CD-ROM.
`Like its predecessor, the Travelpilot displays a road mapof the area aroundthe vehicle, as
`illustrated by Fig. 29.7. The vehicle location and heading is indicated by the arrowhead icon
`below the center of the screen. The vertical bar at the right edge of the mapindicates the dis-
`
`Destination
`
`Destination
`
`North
`
`Between Two Stars
`
`
`
`* Main Menu|! oocy .
`:
`f
`Zoom Out
`
`* Map Top North
`a
`Map Scale
`
`1/8 - 30 mi.
`Destination Info |)
`1 mile
`Other St. Names
`
`shown
`
`
`Shift Cursor
`|f
`
`|}
`Zoom In
`Left or Right
`
`Current Location
`Current
`and Direction
`
`Destination
`of Travel
`Brightness
`* No access whenvehicle is moving.
`Control
`FIGURE 29.7 Bosch Travelpilot display and controls, (Bosch literature)
`
`645
`645
`
`

`

`29.12
`
`EMERGING TECHNOLOGIES
`
`play scale which can be zoomed in to % mile for complete street detail or out to 30 miles to
`show only major highways. The map is normally oriented such that the direction in which the
`vehicle is heading points straight up on the display, thus allowing the driver to easily relate the
`map display to the view outside.
`Whenparked, a menu accessible through the MEN button permits use of soft-labeled but-
`tons in a scrolling schemeto enter destinations by street address, intersection, etc. Travelpilot
`uses a process called geocoding to locate an input destination and display it as a flashing star
`on the map.Asillustrated in Fig. 29.7, a destination geocodedby street address is bracketed
`by two flashing stars when the mapis zoomedin.In this case, the stars mark the block whose
`address range includes the street numberof the destination. A line of information across the
`top of the map display indicates the crow-flight distance and points the direction from the
`vehicle’s current location to the destination. Up to 100 input destinations may be stored for
`future use.
`A submenuprovides several methodsforthe driver to reset the vehicle’s position on the map
`if the Travelpilot gets off track. The frequency with which the system requires reinitializing
`depends upon dead-reckoning anomalies and the completeness and accuracy of the map data
`for the area being driven. For example, map matchingtypically fails once in a thousand miles
`when operating in an environmentlike greater Los Angeles or North Texas. As for location
`accuracy therest of the time (i.e., with map-matching operative), Travelpilot is claimed to have
`infinitesimalerror relative to the map. The map-matching performance is comparedto that of a
`servo-amplifier in which map-matching failure correspondsto loosing servo-lock to the map.
`The Travelpilot hardware includes a V50 processor, 4-Mb DRAM,64-Kb EPROM,and 8
`Kbof nonvolatile RAM for storing vehicle location while the ignition is off, calibration fac-
`tors, up to 100 saved destinations, etc. The Travelpilot may interact with other devices through
`an RS-232 serial port and an expansion cardslot. For example, Travelpilots in 400 Los Ange-
`les fire trucks and ambulances are connected by digital packet radio to the city’s emergency
`control center. The emergency operators can monitor each vehicle’s location and status, and
`can send destinations directly to a vehicle’s Travelpilot for emergency dispatch.
`
`29.3.2 Toyota Electro-Multivision
`
`The Toyota Electro-Multivision has undergone numerousrefinementssince it was introduced
`in 1987 as the first sophisticated navigation system available as a factory option on automo-
`biles sold in Japan. Except for a few features,it is representative of the more comprehensive
`models of navigation systems now available in Japan from almostall of the major automobile
`and electronics manufacturers.
`Many Electro-Multivision features may be summarized with reference to those of the
`Travelpilot previously described in more detail. Both use dead reckoning and digitized maps
`stored on CD-ROM for display on a CRT screen with an icon representing presentposition,
`and are generally similar in their basic navigation features. However, a raster-scan color CRT
`rather than a vector-drawn monochromatic CRT is used in the Electro-Multivision. Also
`unlike Travelpilot, the Electro-Multivision map database includes yellow pages information
`such as the locationsoffacilities likely to be of interest to motorists.
`The Electro-Multivision also serves as a referenceatlas. In the original version, for exam-
`ple, a display showsa color mapof all Japan with 16 superimposedrectangles. Touching a par-
`ticular rectangle causes the map area it encompasses to zoom andfill the entire screen, again
`with grid lines superimposed to form 16 rectangles. Thus, a few touchesof the screen takes the
`driver from an overview of the entire country down to major roads and landmarks in some
`quarter of Tokyo.
`However, in spite of Electro-Multivision’s sophisticated map-handling capabilities, map
`matching was not used in the first version because the digital maps then available for Japan
`did not contain sufficient detail at the city street level. In addition to detailed digital maps and
`map matching, subsequentversions of Electro-Multivision include a GPSreceiver and a color
`
`646
`646
`
`

`

`NAVIGATION AIDS AND IVHS
`
`29.13
`
`LCDrather than CRTdisplay. In 1991, a routing feature was addedto calculate a suggested
`route to specified destinations and highlight the trace on the LCD map display. The most
`recent version’ adds synthesized voice route guidanceinstructions.
`As is the case for most other state-of-the-art navigation systems offered as factory-
`installed equipmentin Japan, the Electro-Multivision navigation features are integrated with
`a full suite of entertainmentfeatures (e.g., AM-FMradio, tape cassette, audio CD player, color
`TV,etc.). In addition, the Electro-Multivision includes a CCD camerafor rear vision on the
`LCDscreen.
`
`29.3.3. Oldsmobile Navigation/Information System
`
`In January 1994, Oldsmobile announcedits Navigation/Information System,the first naviga-
`tion and route guidance system to be offered as a dealer-installed option from an automobile
`manufacturer in the United States. Initially sold only in California, the system was expected
`to be offered nationwide as digital map databases for other areas become available during
`1994-1995.
`The Oldsmobile system integrates a GPS receiver with dead reckoning and map matching.
`The dead-reckoning process uses gyroscopic and odometer inputs. A PCMCIAcardis used
`for storing a map database which includesthe locations of points of interest such as emer-
`gency services, restaurants, major retail stores, schools, office buildings, tourist attractions, etc.
`The major hardware modules of the system are shownin Fig. 29.8.
`Destinations may be entered as specific street addresses or road intersections, or by select-
`ing categories andscrolling through the points of interest included in the database. Routingcri-
`teria (e.g., avoiding expressways) may also be specified. The navigation computer then
`calculates the route and highlights it on a 4-in active matrix color LCD. Once underway,the dis-
`tance to and direction of each turn is displayed on the screen and a voice prompt advises the
`driver as each turn is approached. A representative route guidance screen is shownin Fig. 29.9.
`The Oldsmobile Navigation/Information system is supplied by Zexel USA Corp. andis an
`adaptation of Zexel’s NAVMATE system which has been under development for several
`years specifically for the U.S. market.
`
`29.3.4 TravTek Driver Information System
`
`Whereas these examples of automobile navigation systems are already available in certain
`markets, Travlek was a functional prototype of a navigation-based in-vehicle traveler infor-
`mation system developed specifically for the TravIek [VHSoperationalfield trial conducted
`for a one-year period ending in 1993 in Orlando,Florida. The field trial was a joint public sec-
`tor-private sector project with the primary objective of obtaining field data on the acceptance
`and use by drivers of navigation and other information provided by comprehensive in-vehicle
`systemslinked with traffic operations and other data centers.
`The TravTek project used 100 General Motors automobiles equipped with the system
`shown. schematically in Fig. 29.10 to provide navigation, route selection and guidance,real-
`time traffic information, local yellow pages and tourist information, and cellular phoneser-
`vice.® Most of the automobiles were madeavailable to Orlando visitors through Avis Rent A
`Car for short-term triais and the rest were assigned to local drivers for extended periods. The
`American Automobile Association selected the test subjects and operated a TravTek Infor-
`mation and Services Center which could be accessed via cellular telephone.
`‘TravTek navigation is based on a combination of dead reckoning and map matching, with
`a GPSreceiver playing a “watchdog”role. TravTek’s navigation function superimposes vehi-
`cle location on a map display screen, highlights suggested routes on the color CRT map dis-
`play, and issues route guidance instructions via synthesized voice. Alternatively, turn-by-turn
`route guidanceinstructions may be displayed in the form of simplified graphics.
`
`647
`647
`
`

`

`Display unit
`
`+ Display bracket
`assembly
`
`
`
`noro
`
`(13P DIN)
`
`Main wire harness
`
`[Red] battery +14 v
`
`[Grey] speed sensor (VSS)
`
`[Purple] back-uplight signal
`
`
`
`
`
`[Orange] ignition signal
`
`
`
`
`
`(6P AMP) [Black] GND
`
`a GPSantenna
`~~?
`
` Video cable
`
`
`
`
`Navigation
`computer
`
`+ Computer bracket
`assembly
`
`
`
`FIGURE 29.8 Oldsmobile Navigation/Information System hardware. (Oldsmobile)
`
`Oldsmobile
`1-496 FWY WEST
`OLDS FWY
`
`PhissThe
`
`errion
`
`FIGURE29.9 Oldsmobile Navigation/Informa-
`tion System route guidance screen. (Oldsmobile)
`
`29.14
`
`648
`648
`
`

`

`NAVIGATION AIDS AND IVHS
`
`29.15
`
`sO
`are
`ec
`s
`Hard
`Sontag
`NAVICAR SW
`
`GPS Revr}=TravTek MODS switches Guitkos Suites
`
`ETAK Map DB
`Cellular
`ToRadi
`AAA Directory DB
`oRadio {_
`RW Detog ov SwitchfylelephoneTYG
`
`
`Shunt
`QU
`Wy
`E&CBus
`oe
`BEE
`
`
`Navigation
`
`Processor
`Diagnostic
`Ospare
`
`
`i
`i
`
`Serlal Link
`Controller
`
`
`
`CGA-Analog
`Switch
`(
`P
`
`Parallel C+)cosplayr Converter Video
`
`
`
`
`
`‘
`H/S Switch
`Controller
`
`ToBCM, ECM
`ec Bus
`
`i Maple
`
`
`|
`
`Wheel
`Sensors
`
`TravTek SW
`TravTek DB
`AAA Map DB
`
`DataLinks
`
`BCM ALDL
`Serial Link
`
`Faceplate
`Controller
`
`Switch Control
`
`‘
`
`
`
`Data
`
`
`
`.
`
`Sorial
`
`Diagnostic
`Serial Link
`
`N
`
`on
`
`Crooks
`
`ColorDisplay
`
`Serial
`
`Routing
`Processor
`
`Seria!
`
`RF
`Modem
`
`SMR
`Transceiver
`
`ToSMAT/R
`Antenna
`
`Serial
`
`Power
`Supply
`
`Removable
`Log File
`
`;
`Speech
`Synth + TeRecio
`
`FIGURE 29.10 Architecture of TravTek vehicle system.®
`
`Although functionally realistic, the TravIek in-vehicle system design used some features
`that would not typically appear in a production system. For example, rather than consolidated
`databases stored on a single CD-ROM orother data storage device, TravTek used separate
`map databases stored on separate hard disk drives for navigation processing and route guid-
`ance processing.”
`However, compared to these examples of commercially available navigation and route
`guidance systems, TravIek’s most distinct difference was the capability to superimpose infor-
`mation on current traffic conditions on the map display and to take traffic congestion levels
`into accountin calculating recommendedroutes. Thetraffic information was received over a
`radio link from a special Traffic Management Center (TMC) operated by the City of Orlando
`in conjunction with the Federal Highway Administration and the Florida Department of
`Transportation. The TMC consolidated traffic data from various sources including “probe”
`data consisting of road segmenttravel times received via mobile radio from the TravTek vehi-
`cles themselves.
`
`OTHER IVHS SYSTEMS AND SERVICES
`29.4
`
`A central aspect of IVHS(Intelligent Vehicle-Highway Systems) is the operation of advanced
`traffic management systems(e.g., the TravTek TMCoutlined here) in conjunction with auto-
`mobile navigation and route guidance systems. This requires the use of mobile data commu-
`
`649
`649
`
`

`

`29.16
`
`EMERGING TECHNOLOGIES
`
`nication links between the infrastructure and in-vehicle systems. Although the United States,
`Europe, Japan, and other developed countries are now systematically pursuing [VHS devel-
`opment, selection of mobile data communication approaches remains under consideration as
`this handbook is prepared. However, it
`is generally expected that one or more of the
`approaches characterized in Table 29.1 will be selected for most geographical areas.
`
`TABLE 29.1 Characteristics of Alternative Mobile Data
`Communication Approaches
`
`
`Approach
`Characteristics
`
`FM sideband
`
`Proximity beacon
`
`Inductive loop
`
`Land mobile
`
`Specialized mobile radio
`
`Cellular radio
`
`Mobile satellite
`
`Meteor burst
`
`One-way
`Low data rates
`
`Extended area coverage
`One-way or two-way
`High data rates
`Spot area coverage
`One-way or two-way
`Low data rates
`
`Spot area coverage
`Two-way
`Local area coverage
`Two-way
`Extended area coverage
`Two-way
`Local/extended area coverage
`One-way or two-way
`Wide area coverage
`Two-way
`Wide area coverage
`Involves time delays
`
`The vast scope of IVHSis made easier to comprehend by subdivision into several interre-
`lated and overlapping categories that have been used to structure the [VHS program in the
`United States: Advanced Traffic Management Systems (ATMS), Advanced Traveler Informa-
`tion Systems (ATIS), Advanced Vehicle Control Systems (AVCS), Commercial Vehicle Oper-
`ations (CVO), Advanced Public Transportation Systems (APTS), and Advanced Rural
`Transportation Systems (ARTS).
`
`29.4.1 Advanced Traffic Management Systems (ATMS)
`
`ATMSincludes freeway surveillance and incident detection, changeable messagesigns, elec-
`tronic toll collection, and coordination oftraffic signal timing over wide areas in response to
`real-time traffic conditions. Major elements of ATMS have been around for decades. Thefirst
`computerized traffic signal control systems were developed in the 1960s, and approximately
`200 computerizedtraffic signal control systems were in use in North America by the end of
`the 1980s. About 25 major freeway surveillance and control systems were in use, including
`many dating from the 1960s and 1970s. Electronictoll collection did notstart experiencing sig-
`nificant implementation until the 1990s.
`An additional ATMSfunction is to supply real-time traffic information (e.g., link travel
`times) over mobile data communication links to ATIS. The final selection of one or more com-
`munication links is unsettled because, amongotherthings, their requirements(e.g., data rates)
`are highly dependent upon system architecture and the division of functions between infra-
`structure and in-vehicle equipment.
`
`650
`650
`
`

`

`29.4.2. AdvancedTraveler Information Systems (ATIS)
`
`NAVIGATION AIDS AND IVHS
`
`29.17
`
`ATISsystems acquire, analyze, communicate, and present information toassist surface trans-
`portation travelers in moving from onelocation to another. Initially called ADIS (Advanced
`Driver Information Systems) by Mobility 2000 and essentially limited to navigation, route
`guidance, and traffic information presented by in-vehicle systems, ATIS concepts now also
`encompass the provision of transit schedules and connections to home,office, kiosk and hand-
`held PPATIS(Portable ATIS) units as well as in-vehicle units. Vision enhancement devices for
`drivers also fall under the ATIS category.
`Although PPATISconcepts are proliferating, most early ATIS marketactivity is expected
`to be what wasoriginally called ADIS andwill be centered on in-vehicle navigation and route
`guidance systems. A 1991 Delphi study by the University of Michigan forecasts some form of
`navigation incorporating GPS will be used in 5 percentof all vehicles sold annually by 2000
`and in 50 percent by 2012. [VHSstrategic planning assumes that manufacturers will sell 2.5
`million vehicles annually with factory-installed ATIS by the year 2000.
`Thepotential of the ATIS marketis also illustrated by the fact that approximately 500,000
`sophisticated automobile navigation systems had already been sold (mostly as factory
`options) in Japan by the end of 1993, even though they must operate autonomously because
`mobile communication links to ATMStraffic operations centers for enabling dynamic route
`adjustment according to traffic conditions have thus far been limited to developmentaltests.
`
`29.4.3 Advanced Vehicle Control Systems (AVCS)
`
`Whereas ATISassists drivers by providing informationto facilitate efficient and safe opera-
`tion, AVCS provides direct assistance with vehicle control. An existing example is ABS
`(antilock braking system). Other early forms of AVCSinclude obstacle detection and warn-
`ing systems andintelligent cruise control. Intelligent cruise control automatically adjusts
`speed according to distance and speed of the vehicle being followed, and enables platooning
`concepts wherein closely spaced vehicles travel in groups to increase lane capacity andsafety.
`AVCSmayultimately lead to fully automated chauffeuring.
`Most of the more advanced forms of AVCSsuch as automatic lane keeping (lateral steer-
`ing control) are still in the laboratory stage. Although driver warning, perception enhance-
`ment, and assistance/control systems are under active research and testing in the United
`States, Europe, and Japan, the most comprehensive demonstrations to date have been accom-
`plished under Europe’s PROMETHEUSprogram.
`
`29.4.4 Commercial Vehicle Operations (CVO)
`
`In addition to benefiting from ATMS, ATIS, and AVCSfunctions, commercial vehicle opera-
`tions may be made more productive through additional IVHS functions. These include auto-
`matic vehicle location monitoring, computerized dispatch and fleet management systems for
`dynamic scheduling and routing, weigh-in-motion (WIM), automatic vehicle classification
`(AVC), automatic vehicle identification (AVI), on-board data acquisition computers,etc.
`The earliest CVO applications were for managingcritical urbanfleets(e.g., police vehicles
`starting in the 1970s). However, extensive application of communication andlocation report-
`ing schemesto long-distance trucking fleets got underway in the 1980s. Much of the present
`CVOactivities (e.g., AVI, AVC, WIM) focus on this application with the objective of elimi-
`nating stops and regulatory paperwork now required whentraveling from state to state.
`
`29.4.5 Advanced Public Transportation Systems (APTS)
`
`APTS encompasses some forms of CVO (e.g., automatic vehicle location reporting), as well
`as additional functions such as schedule monitoring for transit buses. APTS also includes
`
`651
`651
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`

`29.18
`
`EMERGING TECHNOLOGIES
`
`HOV(high-occupancy vehicle) lanes and instant car-pooling services. Although AVL imple-
`mentation for transit buses was limited until the present generation of GPS-based systems
`started becoming available, extensive research and trials were conducted during the 1970s
`under auspices of the Urban Mass Transit Administration (recently renamed Federal Transit
`Administration). The use of AVL and communications technologies to monitor, control, and
`manage public transit continues to be a central thrust of APTS.
`New APTSthrusts include making timely and accurate information on traffic conditions
`and on transit and ride-sharing alternatives readily available to travelers (especially com-
`muters who normally drive alone) for pretrip planning. Anotheris to improve the customer
`interface throughthe use of integrated electronic fare systems such as smart cardsvalidforall
`transportation modes, and through the provision of real-time transit service information at
`homes, offices, and public places as well as at stops, aboard vehicles, etc. APTS also includes
`systems for controlling HOV access and enforcing proper usage.
`
`29.4.6 Advanced Rural Transportation Systems (ARTS)
`
`ARTShas the greatest overlap with other segments of the [VHSindustry in that few,if any,
`additional functions or technologies are required. Instead, safety dominates rural TVHSplan-
`ning with emphasis on in-vehicle safety advisory and warning systems, prevention of single-
`vehicle off-road accidents, prevention of passing accidents, warnings of animals on or near the
`roadway, vision enhancement, and Maydaycalls from stranded vehicles. Althoughvirtuallyall
`of these may evolve under other IVHS segments, ARTS communications considerationsdif-
`fer significantly from those of urban areas because lower population densities and fewer
`roads combined with greater distances among facilities require greater dependence upon
`wide-area communications.
`
`REFERENCES
`
`1. R. L. French, “Historical overview of automobile navigation technology,” Proceedings, 36th IEEE
`Vehicular Technology Conference, Dallas, Texas, May 20-22, 1986, pp. 350-358.
`2. D.A. Rosen, Mammano, F. J., and Favout, R.,“An electronic route guidance system for highway vehi-
`cles,” IEEE Transactions on Vehicular Technology, vol., VT-19, 1970, pp. 143-152.
`3. R.L. French, “Evolution of automobile navigation in Japan,” Proceedings, 49th Annual Meeting of the
`Institute of Navigation, Cambridge, Massachusetts, June 21-23, 1993, pp. 69-74.
`4. R.L. French, “Map matching origins, approaches, and applications,” Proceedings, Second International
`Symposium on Land Vehicle Navigation, Munster, Germany, July 4-7, 1989, pp. 93-116.
`5. J.L. Buxton, Honey, S. K., Suchowerskyj, W. E., and Tempelhof, A., “The Travelpilot: a second-genera-
`tion automotive navigation system,” IEEE Transactions on Vehicular Technology,” vol. 40, no. 1, 1991,
`pp. 41-44.
`6. K. Ishikawa, Ogawa, M., Azuma,S., andIto, T., “Map navigation software of the Electro-Multivision of
`the °91 Toyota Soarer,” Proceedings, VNIS’91—Vehicular Navigation & Information Systems Confer-
`ence, vol. 1, Dearborn, Michigan, Oct. 20-23, 1991, pp. 463-473. [Also known as SAE Paper No. 912790.]
`7. T. Ito, Azuma,S., and Sumiya, K., “Developmentof the new navigation system—Voice Route Guid-
`ance,” Society of A