PCT
`
`WORLD lN'l'E.IJ£Cl'UAI._ PROPERTY ORGANIZATION
`International Bureau
`
`INTERNATIONAL APPLICATION PUBLISHED UNDER THE PATENT COOPERATION TREATY (PCT)
`WO 96/02853
`
`(11) International Publication Number:
`
`(51) International Patent Classification 5 :
`G018 13/93
`
`(43) International Publication Date:
`
`1 February 1996 (01.02.96)
`
`(21) International Application Number:
`
`PC!‘/GB95/01670
`
`(22) International Filing Date:
`
`14 July 1995 (l4.07.95)
`
`(30) Priority Data:
`94l4393.0
`
`15 July 1994 (15.07.94)
`
`GB
`
`(81) Designated States: AM. AT, AU, BB. BG, BR, BY, CA, CH,
`CN. CZ. DE, DK. EE. ES, FI, GB, GB, I-IU. JP, KE, KG,
`KP, KR, KZ, LK. LR. LT. LU, LV, MD, MG, MN, MW,
`MX, NO, NZ. PL. PT. RO, RU, SD, SE, SI. SK, TI, TI‘,
`UA. US. UZ. VN, European patent (AT, BE, CH, DE, DK,
`ES. FR, GB, GR, IE. IT. LU, MC, NL, PT, 3
`. OAPI
`patent (BF. BJ. CF, CG, CI. CM, GA, GN, ML, MR, NE.
`SN, TD, TG), ARIPO patent (KE, MW, SD, SZ. UG).
`
`(71) Applicant (for all designated States except US): DESIGN
`TECHNOLOGY AND INNOVATION LTD. [GB/GB]; The
`Barn, Ripe Lane, Ripe, Lewes, Sussex BN8 6AP (GB).
`
`Published
`Without international search report and to be republished
`upon receipt of that report.
`
`(72) Inventor; and
`(75) InventorlApplieant (for US only): TONKJN, Mark [GB/GB];
`The Barn, Ripe Lane, Ripe, Lewes. Sussex BN8 6AP (GB).
`
`(74) Agent: HEPWORTH LAWRENCE BRYER & BIZLEY; Mer-
`lin House. Falconry Court, Baker's Lane. Epping, Essex
`CMI6 SDQ (GB).
`
`(54) Title: SAFETY SYSTBVI FOR VEHICLES
`
`(57) Abstract
`
`system comprising
`The
`fitted to a subject
`a controller
`vehicle (16) and sensor means
`(20) operable to sense a distance
`of separation and relative velocity
`of a trailing vehicle (18). Also
`input
`to
`the
`controller
`is
`a
`velocity
`signal
`derived
`from
`a velocity sensing means
`(97)
`determining the ground speed
`of
`the
`subject
`vehicle
`using
`a doppler
`radar system.
`The
`controller
`calculates
`a
`safety
`envelope and activates a visible
`warning device attached to the
`rear of the subject vehicle if the trailing vehicle penetrates the safety envelope. An enhanced safety envelope determined by adverse road
`conditions is also established, any incursion into the enhanced envelope resulting generally in the visible warning being at a less prominent
`level. If however the closing speed of the trailing vehicle exceeds a predetermined threshold, penetration of the enhanced envelope results
`immediately in the full warning being displayed with full prominence to the driver of the trailing vehicle. The system has application to
`improving the safety of road vehicles.
`
`20
`
`16
`
`18
`
`A
`
`O A
`
`.
`
`U U 0
`
`Volkswagen Group of America, Inc., Petitioner
`Case No. |PR2015-00276
`1
`
`VWGoA - Ex. 1006
`Volkswagen Group of America, Inc., Petitioner
`Case No. IPR2015-00276
`1
`
`

`
`FOR THE PURPOSES OF INFORMATION ONLY
`
`Codes used to identify States party to the PC!‘ on the front pages of pamphlets publishing international
`applications under the PCT.
`
`AT
`All
`BB
`BE
`BF
`136
`BJ
`BR
`BY
`CA
`CF
`CG
`CH
`CI
`CM
`CN
`CS
`CZ
`DE
`
`Austria
`Australia
`Barbados
`Belgium
`Burlriaa Faso
`Bulgaria
`Benin
`Brazil
`Belanu
`Canada
`Central African Republic
`Congo
`Switzerland
`Cote d‘lvoire
`Cameroon
`China
`Czechoslovakia
`Czech Republic
`Germany
`
`United Kingdom
`Georgia
`Guinea
`Greece
`Hungary
`Ireland
`Italy
`Japan
`Kenya
`Kyrgyslan
`Democratic People's Republic
`of Korea
`Republic of Korea
`Kazakhstan
`Liechtenstein
`Sri Lanka
`Luxembourg
`Latvia
`Monaco
`Republic of Moldova
`Madagascar
`Mali
`Mongolia
`
`Mauritania
`Malawi
`Niger
`Netherlands
`Norway
`New Zealand
`Poland
`Portugal
`Romania
`Russian Federation
`Sudan
`Sweden
`Slovenia
`Slovakia
`Senegal
`Chad
`Togo
`Tajikistan
`Trinidad and Tobago
`Ukraine
`United State: of America
`Ulbelristan
`Viet Nam
`
`2
`
`

`
`WO 96102853
`
`PCTIGB95/01670
`
`1
`
`SAFETY SYSTEM FOR VEHICLES
`
`The invention relates to vehicle safety systems including
`
`warning means which provide safety information for example
`
`to drivers of following vehicles.
`
`A known warning means comprising a vehicle display system
`
`is described in W093/15931 which provides a display system
`
`which
`
`indicates discrete ranges
`
`of deceleration of
`
`a
`
`vehicle and which can also provide a display to indicate
`
`that the vehicle is stationary. All
`
`the features of that
`
`display system are
`
`incorporated in this
`
`specification
`
`especially when referring to 23 progressive brake warning
`
`(PBW) or vehicle stationary indicator
`
`(VSI) display.
`
`known
`
`ground
`
`speed measuring
`
`device
`
`is disclosed
`
`A
`
`in
`
`W092/01951 which uses a double horned radar device, again
`
`the
`
`teachings
`
`of
`
`that
`
`specification are
`
`incorporated
`
`herein.
`
`The invention seeks,
`
`inter alia,
`
`to improve known vehicle
`
`display systems and ground speed measuring systems.
`
`According to one aspect of the invention there is provided
`
`a safety system for vehicles comprising a controller fitted
`
`in use to a subject vehicle,
`
`sensor means fitted to the
`
`subject vehicle in use and operable to sense a distance of
`
`separation and/or a relative velocity of a trailing vehicle
`
`and operable to input data signals representative thereof
`
`to the controller, velocity sensing means operable to sense
`
`the velocity of the subject vehicle relative to the ground
`
`and
`
`to
`
`input
`
`to
`
`the
`
`controller
`
`a
`
`velocity
`
`signal
`
`representative thereof, wherein the controller is operable
`
`to processes the received velocity signal and data signals
`
`to determine the existence of an unsafe condition, and the
`
`safety system further comprising warning means controlled
`
`3
`
`

`
`WO 96102853
`
`PCTlGB95l016'70
`
`I 2
`
`the
`by the controller and operable to warn a driver of
`trailing vehicle of the existence of the unsafe condition.
`
`is operable to determine the
`Preferably the controller
`existence of
`the unsafe condition by determining a safe
`
`distance corresponding to a safety envelope to the rear of
`
`the subject vehicle within which any incursion by
`
`the
`
`trailing vehicle constitutes the existence of
`
`an unsafe
`
`condition.
`
`This provides the advantage of assisting the driver of the
`
`trailing vehicle to more accurately determine the safe
`
`distance, drivers typically tending to underestimate the
`
`safe distance in the absence of any such warning system.
`
`The safe distance may be determined to be substantially the
`
`safe stopping distance of
`
`a vehicle travelling at
`
`the
`
`velocity of the trailing vehicle.
`
`The
`
`safe
`
`stopping distance may
`
`be
`
`determined
`
`to be
`
`proportional to the velocity of the subject vehicle.
`
`Preferably the warning is terminated after
`
`the measured
`
`value reaches a safe value.
`
`The warning can be provided by
`
`a display operably carried by the subject vehicle and
`
`positioned for viewing by
`
`the driver of
`
`the trailing
`
`vehicle, and the display can comprise a row of lights.
`
`The system may comprise means for warning that the subject
`
`vehicle is stationary.
`
`The
`
`system can further comprise
`
`means
`
`for
`
`providing warning
`
`of different
`
`levels
`
`of
`
`deceleration of the subject vehicle.
`
`The warning means can
`
`comprise an orange light display for
`and/or
`relative separation conditions
`
`the relative speed
`and a
`red light
`
`display for
`
`the vehicle
`
`stationary and/or
`
`levels
`
`of
`
`4
`
`

`
`WO 96102853
`
`PCl‘lGB95I0 1670
`
`3
`
`deceleration conditions.
`
`The relative separation and/or
`
`relative speed warning may be overridden by the level of
`
`deceleration warning.
`
`The system in a preferred embodiment has a radar device
`
`having
`
`two
`
`receiver
`
`antenna which
`
`device
`
`operably
`
`communicates with a controller which is able thereby to
`
`determine the direction of motion of
`
`the vehicle,
`
`and
`
`warning means which
`
`is
`
`automatically actuated by
`
`the
`
`controller to provide a warning when the vehicle moves.
`
`A further warning means can be automatically activated when
`
`the vehicle reverses and may comprise an array of
`
`lights
`
`and/or means for generating sound.
`
`The control1er~ may be operable to determine an enhanced
`
`safe distance corresponding to an enlarged safety envelope
`
`and the warning means may be further operable to indicate a
`
`first level of warning corresponding to incursion by the
`
`trailing vehicle into the enlarged safety envelope and a
`
`second level of warning which is more prominently presented
`
`to the driver
`
`than the
`
`first
`
`level
`
`of warning
`
`and
`
`corresponds to any incursion into the safety envelope.
`
`The size of the enhanced safe distance and enlarged safety
`
`envelope will
`
`generally
`
`be
`
`predetermined
`
`so
`
`as
`
`to
`
`correspond to typical parameters appropriate for driving
`
`under adverse road conditions.
`
`These parameters may for
`
`example
`
`be
`
`stored in a
`
`look
`
`up
`
`table
`
`allowing
`
`the
`
`parameters to be determined from the signals received by
`
`the controller together with the parameters defining the
`
`normal safety envelope.
`
`The
`
`safety
`
`system may
`
`comprise
`
`ground
`
`condition
`
`communication means operable to input to the controller a
`
`5
`
`

`
`WO 96/02853
`
`PCTIGB95I01670
`
`4
`
`signal representative of the condition of the ground and or
`
`other driving conditions
`
`and wherein the controller
`
`is
`
`operable
`
`to
`
`determine
`
`the
`
`enhanced
`
`safe
`
`distance
`
`corresponding to the enlarged safety envelope according to
`
`the extent
`
`to which the ground condition communication
`
`means indicates adverse ground conditions likely to affect
`
`traction between the subject vehicle and the ground.
`
`The enhanced safety distance and enlarged safety envelope
`
`may’
`
`thereby be made adaptable to the prevailing’ driving
`
`conditions and the ground condition communication means
`
`would preferably function automatically to input data such
`
`as whether
`
`rain,
`
`ice or
`
`snow was presenting a driving
`
`hazard,
`
`the source of
`
`the data being either
`
`on board
`
`sensors or telemetric links to an external system providing
`
`relevant data.
`
`Preferably the sensor means is operable to sense both the
`
`distance of separation and.
`
`the relative velocity of
`
`the
`
`trailing vehicle
`
`and
`
`the
`
`controller
`
`is
`
`operable
`
`to
`
`determine whether
`
`the relative velocity of
`
`the trailing
`
`vehicle relative to the subject vehicle when entering the
`
`enlarged safety envelope is greater than a threshold value
`
`of relative velocity and,
`
`if so,
`
`is operable to actuate the
`
`warning means to indicate the second level of warning.
`
`This has the advantage of delivering a warning with full
`
`prominence to the driver of the trailing vehicle before the
`
`trailing vehicle has reached the main safety envelope in
`
`order to give the maximum available warning to the driver
`
`that his closing speed to the subject vehicle is excessive.
`
`In
`
`a
`
`preferred
`
`embodiment
`
`the
`
`ground
`
`condition
`
`communication means comprises means fitted to the subject
`
`vehicle for sensing at least one of rain,
`
`snow and ice and
`
`6
`
`

`
`WO 96/02853
`
`PCTlGB95/0 1670
`
`5
`
`communicating
`
`a
`
`signal
`
`representative
`
`thereof
`
`to
`
`the
`
`controller.
`
`The sensor means for sensing the distance and velocity of
`
`the
`
`trailing vehicle may
`
`comprise
`
`a
`
`radar
`
`system
`
`transmitting and
`
`receiving
`
`radar
`
`pulses,
`
`from which
`
`received pulses
`
`information
`
`is
`
`derived
`
`sufficient
`
`to
`
`determine both the proximity and relative speed of
`
`the
`
`trailing vehicle.
`
`The safety system may comprise communication means operable
`
`between the controller of the subject vehicle and a warning
`
`device fitted in use to the trailing vehicle, whereby the
`
`warning means
`
`is operable to indicate a warning to the
`
`driver of the trailing vehicle via the warning device.
`
`The velocity sensing means may comprise a conventional
`
`speed sensing device fitted to the vehicle's transmission
`
`train and may for example include a hall effect sensor.
`
`The velocity sensing means may alternatively comprise a
`
`sensor mounted
`
`on
`
`the
`
`subject vehicle
`
`and
`
`responsive
`
`independently
`
`of
`
`elements
`
`of
`
`the
`
`subject vehicle's
`
`transmission train to movement of
`
`the ground relative to
`
`the subject vehicle.
`
`In
`
`a preferred embodiment
`
`the velocity sensing means
`
`comprises
`
`a sensor constituted by a doppler shift
`
`radar
`
`device.
`
`An advantage of such sensing means is that it is free from
`
`the
`
`errors
`
`inherent
`
`in determining velocity via
`
`the
`
`transmission train which arise from variation in tyre
`
`diameter due to varying inflation pressure,
`
`tyre wear or
`
`other factors.
`
`7
`
`

`
`W0 96/02853
`
`PCTIGB95/01670
`
`6
`
`The controller may also be operable to actuate an impact
`absorbing device deployed internally or externally of
`the
`
`subject vehicle.
`
`bag
`an air
`comprise
`absorbing device may
`impact
`The
`inflatable so as to be deployed externally of the subject
`vehicle and/or bumpers extensible by means of hydraulic
`
`rams operable to absorb energy upon impact.
`
`The effects of
`impact may thereby be attenuated prior to
`the point of collision between the subject vehicle and an
`object which may be a trailing vehicle for example.
`
`system for
`a
`the invention provides
`Another aspect of
`vehicles having means
`for determining the magnitude of
`acceleration and deceleration of
`the vehicle and output
`
`and
`acceleration
`of
`the magnitude
`enabling
`means
`deceleration to be interpreted by a third party remote from
`
`the vehicle.
`
`The output means
`
`can comprise a visible
`
`having
`display
`acceleration and
`
`a
`
`a
`
`first
`second
`
`form of
`form of
`
`for
`representation
`representation for
`
`deceleration.
`
`The display can comprise an array of lights
`
`mountable on the side of a vehicle.
`
`A first coloured array
`
`can represent acceleration and a second coloured array can
`represent deceleration and preferably the number and/or
`intensity of actuated lights of a given colour represents
`the magnitude of the acceleration or deceleration.
`
`This aspect of the invention has application for example to
`racing cars and motorcycles where a visible display mounted
`on either or both sides of the vehicles enable spectators
`
`acceleration or
`rate of
`the
`to perceive
`cameras
`and
`deceleration of
`the vehicle thereby adding interest
`and
`enjoyment.
`Such displays would not be visible necessarily
`
`8
`
`

`
`WO 96/02853
`
`PCl‘IGB95I01670
`
`7
`
`to the leading or trailing drivers so as to cause minimal
`
`interference with the conduct of racing.
`
`Also disclosed herein is a management system for a vehicle
`
`comprising
`
`a
`
`ground
`
`speed
`
`sensor
`
`having means
`
`for
`
`determining the true speed and direction of travel of the
`
`vehicle and means for communicating the speed and direction
`
`of
`
`travel of
`
`the vehicle to 2: controller which operably
`
`controls a second vehicle device in response to the speed
`
`or direction information.
`
`Preferably the system is adapted to perform any one, or any
`
`combination of the following functions: active sensing for
`
`cruise control, or comparison with actual wheel speeds for
`
`anti-lock braking systems and/or active traction control,
`
`provision of any one of the following: driving speed over
`
`ground display, distance covered, fuel economy measurement,
`
`elapsed journey time and estimating time of arrival at
`
`destination, average fuel economy over
`
`journey; automatic
`
`triggering of airbags; change gear in electronic automatic
`
`transmission vehicles.
`
`Such a system can also include the features of all
`
`the
`
`other aspects of the invention.
`
`According to a
`
`further aspect of
`
`the invention there is
`
`disclosed a safety system for vehicles comprising an anti-
`
`lock braking system fitted to a
`
`subject vehicle
`
`and
`
`operable to regulate operation of
`the subject vehicle's
`brakes in response to a signal generated by a speed sensor
`
`and representative of
`
`the speed of
`
`the subject vehicle
`
`relative to the ground, characterised in that
`
`the speed
`
`sensor
`
`is a
`
`radar
`
`system operable to direct
`
`radiation
`
`towards the ground and to determine the speed by receiving
`
`and analysing radiation reflected from the ground.
`
`9
`
`

`
`WO 96/02853
`
`PCl'IGB95I0l670
`
`system: may be operable to determine speed by
`radar
`The
`measurement of
`a doppler shift
`in the frequency of
`the
`
`reflected radiation.
`
`there is
`the invention,
`According to a further aspect of
`disclosed a safety system for vehicles comprising at least
`one
`impact energy absorbing device fitted to a subject
`vehicle,
`sensor" means fitted to the subject. vehicle and
`
`the proximity and closing speed of an
`operable to detect
`object external
`to the subject vehicle, determining means
`responsive to output
`signals of
`the sensor means
`for
`determining whether the object is about to impact with the
`
`responsive to the
`subject vehicle and actuating means
`determining means to actuate the at least one impact energy
`absorbing device
`so as
`to be deployed at
`a position
`externally of the subject vehicle so as to be between the
`
`object and the subject vehicle.
`
`The impact energy absorbing device may be an inflatable bag
`device comprising two or more inflatable bags deployed when
`inflated so as to constitute successive layers including an
`
`inner bag proximate the subject vehicle and an outer bag
`
`distal to the subject vehicle.
`
`The
`
`safety system preferably comprises deflation means
`
`operable to deflate one or more of the bags in response to
`pressure within
`the
`respective
`bag
`exceeding
`a
`
`predetermined pressure level.
`
`The deflation means may be operable to deflate bags
`
`in
`
`successive
`layers
`at
`pressure
`levels which
`decrease
`progressively from the inner bag to the outer bag whereby
`in use the outer bag is deflated prior to deflation of the
`
`10
`
`

`
`WO 96/02853
`
`PCT/GB95/01670
`
`9
`
`inner bag in response to impact between the object and the
`
`subject vehicle.
`
`The deflation means may
`
`comprise
`
`rupturable membranes
`
`forming parts of side walls of respective bags and arranged
`
`to rupture at respective predetermined pressure levels.
`
`In a preferred embodiment
`
`the air bag device comprises
`
`three inflatable bags.
`
`(The preferred comprising a plurality of air bag devices
`
`located so as to be deployed at the front, rear,
`
`left side
`
`and right side respectively of the subject vehicle
`
`Alternatively the impact energy absorbing device comprises
`
`at
`
`least one bumper extensible by means of hydraulic ram
`
`means capable of absorbing energy when the bumper receives
`
`an impact.
`
`A yet
`
`further aspect of
`
`the invention provides a safety
`
`system for vehicles comprising a ground speed measuring
`
`device
`
`and/or
`
`input detection means
`
`and
`
`a controller
`
`operable to activate a spraying device to release safety
`
`chemicals such as foams when an accident is likely.
`
`Another aspect provides
`
`an antenna
`
`for
`
`a
`
`radar
`
`system
`
`comprising means for coupling the antenna to a radar system
`
`to enable electromagnetic radiation from the radar to be
`
`transmitted through the antenna and for reflected radiation
`
`to be passed back to the radar through the antenna, said
`
`antenna further comprising a body portion which is wedge-
`
`shaped.
`
`The wedge can taper to a tip of
`
`less than lmm
`
`thickness.
`
`Preferably the
`
`antenna
`
`is made at
`
`least
`
`partially of PTFE.
`
`11
`
`

`
`WO 96/02853
`
`PC!‘/GB95I0l670
`
`10
`
`Yet another aspect of the invention provides a housing for
`a
`radar
`system
`having
`means
`for
`communicating
`‘electromagnetic radiation into a waveguide which directs
`the radiation along two paths in two separate directions
`
`the housing being adapted to
`each leading to an output,
`accommodate receiving antennas
`in each of
`the radiation
`
`the housing further comprising wedge—shaped antenna
`paths,
`at
`the outputs for transmitting and collecting reflected
`
`radiation.
`
`The
`
`receiving antenna accommodation can be
`
`separated by half a wavelength of the radiation.
`
`the invention provides a housing for a
`Another aspect of
`radar system having an inlet for electromagnetic radiation
`which leads
`to a waveguide which directs the radiation
`
`along two paths to two separate outlet/inlet horns wherein
`the horns
`taper
`along their
`length in one
`transverse
`
`dimension relative to their longitudinal axis.
`
`The horns can taper outwardly.
`The horns can be turned
`inwardly such that
`radiation emitted from one horn is
`
`directed to intersect with the radiation from the other.
`
`Preferably the housing is
`
`adapted to accommodate
`
`two
`
`receiving dipoles equidistantly spaced from a point where
`
`the two paths meet.
`
`Embodiments of the inventions will now be described, by way
`
`of
`
`example
`
`only, with
`
`reference
`
`to the
`
`accompanying
`
`drawings,
`
`in which:—
`
`FIGURB 1
`
`is a schematic front elevational View of vehicle
`
`display systems according to the invention;
`
`FIGURE 2a is a schematic plan view of two vehicles fitted
`
`with a vehicle display according to the invention;
`
`12
`
`

`
`WO 96/02853
`
`PCTIGB95I0 1670
`
`11
`
`FIGURE 2B shows a second embodiment of the display shown in
`
`Figure 1 in an active state;
`
`FIGURE 3
`
`shows a front elevational view of part of
`
`the
`
`radar system according to the invention;
`
`FIGURE 4 is a plan view from below of the radar part shown
`
`in Figure 3;
`
`FIGURE 5
`
`is a rear elevational view of
`
`the radar device
`
`shown in Figures 3 and 4; whilst
`
`FIGURE 6 is a sectional view taken along 6-6 of Figure 5;
`
`FIGURE 7 provides five views
`
`(A to E) of a wedge device
`
`suitable for use
`
`in a
`
`radar
`
`system according to the
`
`invention;
`
`FIGURE 8 provides three views of a second embodiment of a
`
`wedge according to the invention;
`
`FIGURE 9 is a sectional side view of a second radar system
`
`according to the invention;
`
`FIGURE 10
`
`is a plan view of
`
`a vehicle having an airbag
`
`system according to the invention; and
`
`FIGURE 11 provides two sectional side elevation views of a
`
`door panel having airbags according to the invention.
`
`Referring to Figure 1
`
`there is shown a display system 10
`
`according to the invention comprising a safety display
`
`constituted by a first light array 12 for providing warning
`
`signals relating to relative parameters between a subject
`
`vehicle 16 and trailing vehicle 18 as shown in Figure 2a.
`
`13
`
`

`
`WO 96/02853
`
`PCI‘lGB95I0 1670
`
`12
`
`A display comprising a second light array 14 can provide
`information relating to the level of deceleration of
`the
`
`subject vehicle and/or whether the vehicle is stationary or
`not.
`Thus the second light array 14
`is similar to that
`
`described in W093/15931 and can be operated in the same
`
`manner as described therein or alternatively using the
`
`system to be described here.
`
`The second light array 14
`
`lamps 15b,
`lamp 15a and four pairs of
`comprises a central
`15c, 15d and 15e. Central
`lamp 15a can be a central high
`
`mount stop lamp (CHMSL) which is triggered by a switch on
`
`the brake pedals of a vehicle and not used under PBW or VSI
`
`conditions. Pairs of lamps 15b to 15e can then act
`
`in the
`
`same manner as lamps 10 to 17 described in W093/15931 for
`
`example.
`
`when acting as
`a vehicle stationary indicator
`(VSI)
`a
`preferred from of display is to illuminate all lamps 15 in
`the second light array 14 at a starting point
`in a cyclic
`
`variation in the number of
`
`lamps
`
`illuminated.
`
`The second
`
`stage is to deactivate central lamp 15a,
`
`then to illuminate
`
`followed by deactivating both lamps 15b and then
`all lamps,
`lighting all lamps. This is followed by deactivating both
`
`lamps 15c momentarily and then activate all lamps and so on
`until all pairs
`of
`lamps
`have
`been
`deactivated
`in
`
`succession and the cycle begins again.
`
`For example,
`
`the
`
`time period for each step could be less than 1 second and
`
`preferably in the order of 0.1 second.
`
`As can be seen from Figures 1 and 2b,
`
`the individual
`
`lamps
`
`15 are preferably distinguishable from one another.
`
`The
`
`width of separating sections 11 between lamps 15 can be as
`
`much as the width of
`
`the lamps
`
`for example.
`
`In another
`
`form, section 11 can have a variable width to ensure that
`
`the lamps remain distinguishable when a trailing vehicle 18
`is some distance behind.
`A proximity sensor,
`if used only
`
`14
`
`

`
`W0 96/02853
`
`PCTIGB95/01670
`
`13
`
`for
`
`the
`
`function of determining separation need
`
`only
`
`comprise a one horn version of the radar described later.
`
`Thus the stationary indication signal
`
`is found to be very
`
`effective since a clear array of lamps, such as red lamps,
`
`is displayed at the rear of the subject vehicle 16 which is
`dapparently expanding due
`to the outward motion of
`the
`deactivated pairs of lamps. With regard to use of second
`
`light array 14 as progressive brake warning display (PBWD)
`it is found that the initial levels at which the pairs of
`
`lamps 15 are illuminated are optimally for deceleration in
`the ranges 0.05—O.1g and 0.1-O.25g,
`say. Advantageously,
`
`these
`or proximity sensor,
`ranging device,
`by using a
`ranges can be varied depending on the proximity and/or
`closing speed of the trailing vehicle 18.
`For example the
`initial level of PBW could be illuminated for deceleration
`
`in the range 0.025 to 0.05g;
`
`the second level becoming 0.05
`
`the PBW
`for example, and so on. Thus, of course,
`to 0.1g,
`signal could be illuminated at the same time as the first
`light array 12 to provide an enhanced danger warning to a
`driver of a trailing vehicle, or other forms of display as
`
`described later could be provided.
`
`In an improved system over that described in W093/15931, a
`
`radar system similar to that described in W092/01951, or as
`
`described later herein, can be used to provide information
`
`regarding subject vehicle velocity and direction of travel.
`By sampling ground speed measurements rapidly and using a
`
`time reference a microprocessor control
`
`system can for
`
`example provide accurate information about
`acceleration
`or
`deceleration
`at
`any
`
`a vehicle's
`given
`time.
`
`Accordingly,
`
`such a system can suitably be used to control
`
`the display shown on the second light array 14.
`
`15
`
`

`
`WO 96/02853
`
`PCl‘lGB95I0l6'l0
`
`14
`
`Such
`
`a microprocessor control
`
`system linked to such a
`
`ground speed sensor
`
`can be used to provide a velocity
`
`readout
`
`to the driver of
`
`the subject vehicle 16,
`
`also
`
`information regarding the distance covered in a given
`
`journey can be relayed to the driver or otherwise logged.
`
`A key feature is that the speed sensor can very accurately
`
`measure actual,
`
`true or absolute, speed over the ground, or
`
`changes therein.
`
`It is not dependent for example on the
`
`diameter of tyres as is a system which counts the rate of
`
`rotation of a ‘vehicles’
`
`tyres.
`
`Such known systems are
`
`prone to large errors in the order of
`
`5% of
`
`the actual
`
`speed and critically this error increases with use of the
`
`tyres due to wear
`
`(and a reduction of
`
`tyre diameter)
`
`and
`
`also critically with increasing speed of vehicle.
`
`By
`
`inputting information to the microprocessor
`
`regarding
`
`the fuel consumption of
`
`an engine,
`
`fuel
`
`economy can be
`
`calculated and for example information can be provided to
`
`the driver
`
`regarding the most appropriate gear
`
`to be
`
`selected.
`
`Information
`
`regarding
`
`acceleration
`
`or
`
`deceleration can be provided to the driver. Additionally,
`
`in a preferred form,
`
`an acceleration and deceleration
`
`display is provided by an array of
`
`lamps comprising two
`
`rows, one to indicate the level of acceleration for example
`
`in green and
`
`a
`
`second row to indicate the
`
`level
`
`of
`
`deceleration in red.
`
`Such
`
`an array of
`
`lamps
`
`can be
`
`attached to the side of a racing car for example such as a
`
`formula one vehicle in order to provide spectators with an
`
`indication of
`
`the changing speed of
`
`the racing car.
`
`Of
`
`course, alternative displays on the vehicle might be used
`
`instead of rows of lamps.
`
`By providing a keypad or other communication means for a
`
`driver
`
`to input
`
`information to the microprocessor,
`
`a
`
`sophisticated vehicle management
`
`system can be provided.
`
`16
`
`

`
`WO 96/02853
`
`PCTlGB95I0l670
`
`15
`
`For example,
`
`the driver could inform the system of his
`
`present
`
`location and destination such that the system can
`
`calculate the distance of
`
`journey from a database of
`
`journey distances.
`
`The driver can then be provided with
`
`distance
`
`remaining
`
`information and
`
`estimated times
`
`of
`
`arrival,
`
`as well as average fuel
`
`economy over
`
`journey.
`
`Alternatively,
`
`the information might be stored rather than
`
`displayed to the driver and extracted for
`
`example when
`
`servicing
`
`the
`
`vehicle
`
`in
`
`order
`
`to
`
`observe
`
`if
`
`any
`
`significant change in performance of the vehicle has taken
`
`place.
`
`The ground speed sensing system of W092/01951 as adapted
`
`herein,
`
`can also be used in active sensing for cruise
`
`control applications. Additionally, comparison of ground
`
`speed with wheel
`
`speed can be used in anti-lock braking
`
`systems and traction control systems for either two or four
`
`wheel vehicles for example.
`
`Thus, accurate ground speed
`
`measurement can be used to control
`
`the optimum rate of
`
`pumping of brakes
`
`in an ABS
`
`system.
`
`In particular,
`
`an
`
`intelligent ABS
`
`system can be provided which when
`
`the
`
`vehicle is travelling at low speeds, overrides the anti-
`
`lock braking system in order to allow wheel
`
`locking which
`
`can be useful
`
`in certain conditions such as
`
`in snow or
`
`similar conditions.
`
`Similarly,
`
`the accurate ground speed
`
`measurements can be used to compare the speed of revolution
`
`of tyres, or other traction means such as trail wheels or
`
`tank treads for example, of a vehicle in order to enhance
`
`traction control systems.
`
`In known systems an independent
`
`vehicle speed measurement is not made and thus the present
`
`system can be used to accurately predict the required tyre
`
`revolution rate for a given speed.
`
`The display constituted by the first light array 12 shown
`
`in Figure 1 comprises an array of seven lamps 13 which are
`
`17
`
`

`
`WO 96102853
`
`PCI'IGB95I0l670
`
`16
`
`operated using a microprocessor control system not shown.
`The control system is designed to activate display 12 to
`provide a warning signal
`to a driver of
`the trailing
`vehicle 18 when the trailing vehicle is closing too rapidly
`
`example, alternatively a
`for
`on the subject vehicle 16
`warning signal is displayed when the trailing vehicle 18 is
`too close ‘to ‘the subject
`‘vehicle 16.
`Even if ‘they are
`
`travelling at the same speed for example,
`
`there are known
`
`safe stopping distances such as
`
`those published by the
`
`Minister of Transport,
`
`in which a vehicle will stop when
`
`the brakes are applied.
`
`Accordingly,
`
`by
`
`knowing
`
`the
`
`the subject vehicle 16 for example preferably
`velocity of
`using the radar ground sensing system described herein,
`
`which provides
`
`therefore a
`
`true ground speed, or other
`
`means in communication with a microprocessor control system
`
`20
`by using a proximity sensor
`and
`separation of
`the subject vehicle 16
`
`the
`to determine
`from the trailing
`
`vehicle 18
`
`a safety envelope can be created behind the
`
`Intrusion in the envelope by the
`subject vehicle 16.
`trailing vehicle 18 causes an initial level of lamps 13 in
`
`array 12 to be lit.
`
`For
`
`example,
`
`all
`
`lamps
`
`13
`
`could
`
`be
`
`illuminated.
`
`Alternatively, only lamps 13a and 13b might be illuminated
`
`in the first instance when the safe distance is broken by
`
`the trailing vehicle 18 and pair 13c might be illuminated
`
`if
`
`the
`
`trailing vehicle
`
`then
`
`encroaches
`
`a
`
`further
`
`predetermined distance and similarly 13d could be activated
`
`upon
`
`a
`
`further
`
`encroachment.
`
`For
`
`example,
`
`the
`
`safe
`
`separation distance
`
`(or
`
`stopping distance)
`
`of vehicles
`
`travelling at 30mph is 25 metres such that
`
`in an example
`
`lamp 13a might be illuminated if the trailing vehicle 18
`encroaches more than 25 metres behind the subject vehicle
`
`16,
`
`lamp 13b could be illuminated in addition to lamp 13a
`
`if the trailing vehicle gets closer than 20 metres.
`
`Lamp
`
`18
`
`

`
`WO 96/02853
`
`PCl‘lGB95/01670
`
`'17
`
`13c could be
`
`illuminated if the trailing vehicle comes
`
`closer than 15 metres and 13d could be illuminated when the
`
`trailing vehicle reaches 10 metres from the subject vehicle
`
`16.
`
`In a further example, all the lamps may be turned on
`
`and off if the trailing vehicle gets still closer.
`
`Thus
`
`a warning system has been described using a ground
`
`speed
`
`sensor
`
`for
`
`a
`
`subject vehicle
`
`16
`
`coupled
`
`by
`
`a
`
`microprocessor with a proximity sensor 20.
`
`In a more
`
`sophisticate version, proximity sensor 20 could be a radar
`
`device described herein for measuring velocity and could
`
`therefore be used to measure the relative velocity of
`
`a
`
`subject vehicle 16 and trailing vehicle 18.
`
`By knowing the
`
`closing speed of
`
`the trailing vehicle 18 predetermined
`
`values could be used to trigger warning displays if the
`
`closing speed is too great.
`
`For example,
`
`a look—up table
`
`or database could again be provided for unsafe closing
`
`speeds. This look-up table might again be varied according
`
`to the velocity of
`
`the subject vehicle 16
`
`531 a similar
`
`manner
`
`to the safe stopping distance, or safety envelope
`
`distance.
`
`Therefore, whilst
`
`the safety envelope distance
`
`at 30mph is 25 metres,
`
`if the trailing vehicle is closing
`
`too rapidly, say, a difference in speed of 30mph,
`
`then the
`
`warning signal could be activated even when the trailing
`
`vehicle 18 is 50 metres behind the subject vehicle 16.
`
`In an alternative form,
`
`the activation of
`
`the warning
`
`display,
`
`in other words
`
`the value of
`
`the safe limit,
`
`depends on the prevailing road conditions.
`
`It might be,
`
`for example that, a keypad or other communication means is
`
`provided so that the driver can input information regarding
`
`weather conditions.
`
`Alternatively,
`
`a
`
`senso