(19) United States
`(12) Patent Application Publication (10) Pub. No.: US 2002/0005778 A1
`Breed et al.
`(43) Pub. Date:
`Jan. 17, 2002
`
`US 20020005778A1
`
`Publication Classi?cation
`
`............ .. B60Q 1/00
`(51) Int. C1.7 .
`(52) us. Cl. .......................................... .. 340/435; 340/436
`
`(57)
`
`ABSTRACT
`
`(54) VEHICULAR BLIND sPOT
`IDENTIFICATION AND MONITORING
`SYSTEM
`
`(76) Inventors: David S. Breed, Boonton Township, NJ
`(US); Wilbur E. DuVall, Kimberling
`City, MO (US); Wendell C. Johnson,
`Signal Hill, CA (Us)
`
`Correspondence Address:
`
`BRIAN ROFFE’ ESQ
`366 LONG ACRE AVENUE
`WOODMERE NY 11598
`’
`
`(21) APPL NO;
`
`09 $51,362
`
`(22) Filed;
`
`May 8, 2001
`
`Related US, Application Data
`
`(63) Non-provisional of provisional application No.
`60/202,424, ?led on May 8, 2000.
`
`100
`
`_
`
`_
`
`_
`
`_
`
`Arrangement for obtaining Information about ob]ects In an
`environment around a vehicle, e.g., in blind spots of the
`driver of the vehicle, including one or more light emitting
`components arranged on the vehicle for~em1tt1ng Infrared
`light Into the environment around the vehicle and receivers
`arranged on the vehicle for receiving infrared light from the
`environment around the vehicle. The information about the
`objects is obtained based on analysis of the received infrared
`light by a processor, e.g., the distance betWeen the vehicle
`and the object, the velocity of the object and the identity of
`the object. Pattern recognition techniques are preferably
`used to obtain the desired information. Control of the vehicle
`can be effected based on the detection of particular objects
`and their position and velocity, e.g., an audio or visual
`Warning device or a steering Wheel control device.
`
`VALEO EX. 1014
`
`

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`Patent Application Publication
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`Jan. 17, 2002 Sheet 1 0f 17
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`US 2002/0005778 A1
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`Patent Application Publication
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`US 2002/0005778 A1
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`FIG. 2
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`US 2002/0005778 A1
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`135
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`110
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`FIG. 5
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`Patent Application Publication
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`180
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`g E
`/ A
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`Q (52)
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`Patent Application Publication
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`Jan. 17, 2002 Sheet 10 0f 17 US 2002/0005778 A1
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`190 -\
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`FIG. 9
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`Patent Application Publication
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`Jan. 17, 2002 Sheet 11 0f 17 US 2002/0005778 A1
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`~
`1
`
`\
`
`Display
`140, 145
`
`Blind Spot
`MOnItOI 110
`
`i
`
`_
`
`_
`‘
`Warning
`Front Blind Spot
`‘
`Signals &
`L M???“ J ‘ Haptic Actuator 146
`7‘
`/
`
`t
`
`\
`\
`
`‘
`‘
`L
`
`MODULE
`120
`‘
`l
`
`Rer Blind Spot
`Monitor
`113
`
`_
`
`Blind Spot
`Monitor 1 11
`
`t
`
`\ >1
`T
`
`Front Corner
`Blind Spot
`Monitor 1 1 5
`
`I
`
`\
`‘
`
`FIG. 10
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`

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`Patent Application Publication
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`Jan. 17, 2002 Sheet 12 0f 17 US 2002/0005778 A1
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`FIG. 11
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`

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`Patent Application Publication
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`FIG. 12
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`

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`Patent Application Publication
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`Jan. 17, 2002 Sheet 14 0f 17 US 2002/0005778 A1
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`ooobooon
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`\\ \
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`FIG. 13A
`
`FIG. 13B
`
`FIG. 13C
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`Patent Application Publication
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`Jan. 17, 2002 Sheet 15 0f 17 US 2002/0005778 A1
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`321 x
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`310
`
`FIG. 14
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`Patent Application Publication
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`Patent Application Publication
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`Jan. 17, 2002 Sheet 17 0f 17 US 2002/0005778 A1
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`v
`
`Determine Range
`to BS Object
`
`Acquire Image
`
`Extract Features
`
`Identify Object
`
`Update Display
`
`4'
`
`'
`
`+
`
`Calculate Relative
`Velocity
`
`Activaate
`Audio - Visual
`Warnings
`
`Activate
`Hap?c
`Warning
`
`Is Vehicle Turning?
`
`»
`
`FIG. 16
`
`

`

`US 2002/0005778 A1
`
`Jan. 17, 2002
`
`VEHICULAR BLIND SPOT IDENTIFICATION AND
`MONITORING SYSTEM
`
`CROSS REFERENCE TO RELATED
`APPLICATIONS
`
`[0001] This application claims priority under 35 U.S.C.
`§119(e) of US. provisional patent application Ser. No.
`60/202,424 ?led May 8, 2000.
`
`FIELD OF THE INVENTION
`
`[0002] This invention relates to collision avoidance sys
`tems and speci?cally to the detection of objects in the
`various blind spots that surround a truck or automobile and
`the Warning or prevention of the vehicle operator from
`taking an action such as changing lanes When such an action
`might lead to an accident.
`
`BACKGROUND OF THE INVENTION
`
`[0003] During the process of operating a motor vehicle, it
`is necessary for the operator to obtain information concern
`ing the proximity of various dangerous objects and their
`relative velocities for the operator to may sound driving
`decisions, such as Whether or not there is enough time to
`change lanes. This information should be obtained from the
`area that completely surrounds the vehicle. In order to gather
`this information, the operator is frequently required to
`physically turn his or her head to check for occupancy of a
`blind spot, for example. In taking such an action, the
`attention of the driver is invariably momentarily diverted
`from control of the vehicle.
`
`[0004] For an automobile, the blind spots typically occur
`on either side of the vehicle starting approximately at the
`position of the driver and extending backwards sometimes
`beyond the rear of the vehicle. These blind spots depend
`heavily on the adjustment of the angle of the mirror. Dif
`ferent areas are in the blind spot depending on the mirror
`angle. Since it is in general not knoWn Whether or hoW the
`mirror is set for the particular vehicle, a blind spot detector
`must detect objects anyWhere along the side of the vehicle
`regardless of the mirror setting.
`[0005] The problem is more complicated for trucks that
`not only have much larger blind spots along the sides of the
`vehicle but also have a serious blind spot starting in front of
`the right front bumper of the vehicle and extending beyond
`the right door. This blind spot is particularly serious in urban
`driving Where small vehicles, motorcycles, pedestrians,
`bicycles etc. in this area can be completely hidden from the
`vieW of the driver.
`[0006] Many systems have been designed Which attempt
`to rotate the mirror to pick up or alloW a driver to visually
`see the object in the blind spot. This is difficult to do Without
`knowledge of the location of the eyes of the driver. For most
`systems that do not incorporate an occupant sensor capable
`of determining the location of the driver’s eyes, there is a
`risk that the mirrors Will be positioned Wrongly thus exac
`erbating rather than helping the blind spot detection prob
`lem. Also, a system that rotates the mirror Will make the
`driver nervous since he or she Will not be able to see the
`scene that he or she is accustomed to seeing in the mirror.
`[0007] Many systems have also been proposed that display
`a vieW of the blind spot, using a video camera, onto a display
`
`either on the instrument panel or on the Windshield as a
`“heads-up” display. Any system Which displays a picture of
`the object on the screen that is inside the vehicle is also
`going to confuse the driver since he or she Will not be able
`to relate that picture to an object such as another vehicle in
`the blind spot on the side of the host vehicle. Additionally,
`the state of the art of such displays does not provide equally
`observable displays at night or in bright sunlight. Thus,
`displays on a CRT or LCD are not natural and it is difficult
`for a driver to adjust to these vieWs. The lighting of the
`vieWs is too faint When sunlight is present and too bright
`When the vehicle is operating at night. Therefore, none of
`these television-like displays can replace the actual visual
`vieW of the occupant.
`
`[0008] Other systems that are based on radar or ultrasound
`have also not been Widely adopted for reasons related to
`cost, accuracy and false alarms. Both systems use beams of
`energy that can become several feet in diameter by the time
`that they reach the edges of the blind spot and thus can
`confuse a large vehicle or a guardrail, sign, parked car etc.
`tWo lanes over With a vehicle in the blind spot. Some such
`systems attempt to ?lter threatening objects from non
`threatening objects based on the relative speed of the object
`and thus err by eliminating a signi?cant number of such
`threats. A tradeoff exists in all such systems Where, if all
`threatening objects are made knoWn to the driver, the false
`alarm rate becomes unacceptable and the driver soon loses
`con?dence in the system and ignores it. If the false alarm
`rate is kept loW, many dangerous situations are ignored.
`
`[0009] Thus, all the prior art systems discussed above
`have serious failure modes. The lesson is that if a vision
`based system such as the rear vieW mirror is going to be
`replaced With a non-vision system then the non-vision
`system must be almost as good as the vision system.
`
`[0010] Some other problems come about When a vehicle
`strays into the lane of the host vehicle. Most systems Will fail
`to Warn the operator and thus an accident can result. Thus,
`the blind spot problem is really tWo problems relating to the
`motion of the potentially striking vehicle and the potentially
`struck vehicle.
`
`[0011] The problem that is addressed by this invention is
`to determine What information is needed about the object
`that is in the blind spot and then the manner in Which this
`information is presented to the vehicle operator so as to
`eliminate accidents caused by the failure of the operator to
`see such an object. This information includes the accurate
`location of the object relative to the host vehicle, its siZe, its
`relative and/or absolute speed, and the identity or kind of
`object. This information must be knoWn regardless of the
`changes in road geometry such as steep hills and sharp
`curves or changes in environmental conditions. Naturally,
`the system must be loW cost if it is going to be purchased by
`the public.
`
`[0012] Studies have shoWn that giving the driver an extra
`half-second could eliminate as many as 50 percent of the
`accidents. Thus, the risk of an accident must also be com
`municated to the operator in a timely fashion to permit the
`driver to take evasive action or not take a particular action
`such as a lane change.
`
`[0013] What is needed therefore is a system that acts like
`the eyes of the driver and interprets the situation and only
`
`

`

`US 2002/0005778 A1
`
`Jan. 17, 2002
`
`gives a Warning When there is a real possibility of an
`accident. A passive Warning can be given in the form of a
`light on the mirror Whenever an object is in the blind spot but
`an active signal such as an audible signal or an intervention
`in the steering of the automobile can only be provided When
`it is necessary to prevent the accident. This system must
`Work With very high reliability and accuracy since th e
`consequences of an error can be serious injuries or death.
`[0014] 1. Prior Art on Blind Spot Detection Systems
`[0015] In “A Survey of Automotive Collision Avoidance
`Systems” by Uttamkumar Dravidam and Sabri Tosunoglu of
`the Florida International University, the authors provide a
`good revieW of the ?eld of obstacle sensors. What folloWs is
`a summary of their analysis. Obstacle sensors such as used
`for blind spot detection can be divided into three types Which
`Will noW be described:
`[0016] Optical sensors include passive infrared, laser radar
`and vision. They generally are sensitive to external envi
`ronmental conditions, Which may not be a problem for blind
`spot detection since the objects to be detected are usually
`nearby the host vehicle. Passive infrared and vision cannot
`provide a direct measurement of distance to an object unless
`part of the ?eld of vieW is illuminated by a point or
`structured light. Laser radar does provide the capability of
`direct distance measurement, as Will be described beloW, and
`a stereo camera can also provide distance information.
`[0017] AMCW (amplitude modulated continuous Wave),
`FMCW (frequency modulated continuous Wave) and
`impulse radar are not generally affected by adverse envi
`ronmental conditions. Although relatively expensive,
`FMCW radar is a good technique for long-range distance
`measurement providing the object to be measured can be
`sorted out. Radar in general has a high false alarm rate due
`to the large pixel siZe at any signi?cant distance from the
`host vehicle, to multipath effects and re?ections off of signs,
`bridges, guardrails etc.
`[0018] Ultrasonics is good in applications Where only
`short relative distance measurements are required, because it
`is able to provide high distance to the target resolution for a
`relatively loW cost. HoWever, for imaging applications, the
`sloW speed and relatively large pixel siZe renders ultrasonics
`marginal. Also, ultrasonic Waves can be signi?cantly dis
`torted by thermal gradients and Wind.
`[0019] Various researchers have attempted combinations
`of these technologies With the particular combination of
`laser radar and pulse or FMCW being quite advantageous for
`long distance collision avoidance applications.
`[0020] What folloWs in a brief description of the principles
`of operation for different types of sensors including their
`main advantages and disadvantages. For blind spot applica
`tions, sensors should be able to accurately determine the
`location of the object and the speed of the obstacle relative
`to the host vehicle. HoW Well this is achieved can be
`measured With the folloWing indicators:
`[0021] Sensing range: the maximum and minimum
`range over Which the technique can be used.
`[0022] Range Resolution: the relative change in
`range that can be measured.
`[0023] Pixel Resolution: the Width of the beam or
`siZe of the pixel received and to Which the sensor is
`sensitive.
`
`[0024] Response time: hoW quickly the sensor can
`respond to a change in the blind spot occupancy.
`
`[0025] Ultrasonics: These sensors Work by measur
`ing the time-to-?ight of a short burst of ultrasound
`energy typically at a frequency of 40-200 kHZ. The
`time taken for the ultrasonic Waves to travel to and
`return from the obstacle is directly proportional to
`the distance betWeen the obstacle and the host
`vehicle. The main advantage is their relative loW cost
`and small siZe. These sensors are also very sensitive
`to changes in the density of air that can be caused by,
`e.g., high Wind velocity and temperature gradients.
`
`[0026] Passive Infrared: These sensors measure the
`thermal energy emitted by objects. Their main
`advantage is their loW cost and small siZe, and main
`disadvantage is their inability to determine the dis
`tance to a detected object and sloW response time.
`
`[0027] Laser Radar: As With regular radar, tWo tech
`niques exist: (1) a pulsed-beam of infrared light
`coupled With time-of-?ight measurements, and (2)
`the modulation of a continuous light beam. The
`pulsed technique offers long range, high direction
`ality, and fast response time. Its limitations are its
`sensitivity to environmental conditions.
`
`[0028] FMCW or AMCW Radar: This type of radar
`uses modulated microWave frequencies, so that the
`frequency difference betWeen the re?ected and the
`transmitted signal is proportional to the relative
`velocity of the object. When tWo Waves of slightly
`different frequencies are used, the distance to the
`object can also be determiined by the phase relation
`ship betWeen the tWo received re?ections. Despite its
`high cost, this technique offers the advantages of
`being insensitive to environmental conditions, but
`the disadvantage of having a large pixel siZe.
`[0029] Impulse Radar: This radar differs from
`FMCW in that it uses very short pulses instead of a
`continuous Wave. Like FMCW radar, it is insensitive
`to environmental conditions, but the cost is signi?
`cantly loWer than FMCW. Distance can be deter
`mined by time-of-?ight measurements and velocity
`can be determined from successive distance mea
`surements. It also has the disadvantage of having a
`large pixel siZe resulting in a high false alarm rate
`and too little information to permit object identi?
`cation.
`[0030] Capacitive and Magnetic: Capacitive and
`magnetic sensors are able to detect close objects
`(Within about 2 m.), using the capacitance or mag
`netic ?eld variations betWeen electrodes excited at
`loW frequencies, typically about 5 kHZ. Despite their
`limited range, they are loW in cost, and robust to
`external environmental effects. The poor resolution
`compared to other techniques makes it unlikely that
`these devices Will be used for blind spot detection
`since most objects are close to the vehicle.
`
`[0031] Vision Systems: These techniques are based
`on the use of a camera and image-processing soft
`Ware. They are sensitive to external environmental
`conditions; hoWever, this is not a signi?cant short
`coming for blind spot detection.
`
`

`

`US 2002/0005778 A1
`
`Jan. 17, 2002
`
`[0032] Considering now the patent prior art.
`
`[0033] US. Pat. Nos. 4,766,421; 4,926,170; 5,122,796;
`5,311,012; 5,122,796; 5,354,983; 5,418,359; 5,463,384 and
`5,675,326 and International Publication No. WO 90/13103
`are all assigned to the same firm and all describe a modu-
`lated optical system. However,
`these references do not
`disclose a camera and in fact, each receiver is a single pixel
`device. The sensor is not mounted on the side rear view
`mirror but instead is mounted on the rear of the vehicle.
`
`These patents do disclose the use of multiple detectors and
`thereby achieving a sort of mapping of the detected object
`into one of several zones. The references also provide a
`crude velocity measurement of the object moving from one
`zone to another. Otherwise, they do not provide accurate
`ranging.
`
`[0034] All of these patents describe a blind spot detection
`system wherein beams of infrared radiation are sent from the
`interrogating or host vehicle at a significant angle in order to
`illuminate possible objects in an adjacent lane. No direct
`measurement of the distance is achieved, however, in some
`cases multiple detectors are used in such away that when the
`adj acent detected vehicle is very close to the detector, that is,
`below the threshold distance, the sensing of the adjacent
`vehicle is suppressed. In other cases, multiple beams of
`infrared are used and distance is inferred by the reception of
`reflected radiation. The detectors are single pixel devices.
`No attempt is made to image the detected object. Also, no
`attempt is made to directly measure the location of the
`detected object.
`
`[0035] US. Pat. No. 5,008,678 describes a phased array
`radar system wherein the antenna can be made to conform
`to the geometry of an edge of the automobile. The locations
`of the antenna, however, make it difficult to detect many
`objects in the side blind spots. The particular location and
`velocity of such objects are also not accurately determined.
`No image of the device is formed. The device is based on a
`single pixel having a relatively large size making recogni-
`tion and identification of the object impossible.
`
`[0036] US. Pat. No. 5,087,918 describes the use of a
`combination of two types of radar: dual frequency Doppler
`radars and frequency modulated continuous wave radar
`(FMCW). The system provides an indication of the range of
`the object from the vehicle but does not indicate where in a
`plane perpendicular to the vehicle the object is located. Also,
`the system does not apply pattern recognition so that dif-
`ferent types of objects in the blind spot can be identified.
`This patent gives a good description of the limitations of
`radar systems.
`
`[0037] US. Pat. No. 5,229,975 describes a method for
`diagnosing when the system is not operating properly by
`placing an LED outside the vehicle next to the sensor. This
`is a single pixel device and thus no imaging or object
`recognition is possible. Range is not measured directly but
`through a series of sensors whereby each sensor covers a
`particular zone. Thus, no accurate range measurement is
`provided. As the object moves in the blind spot area, it is
`sensed by a variety of the sensors and the last one to sense
`it gives a crude indication of the distance.
`
`[0038] US. Pat. No. 5,235,316 describes an ultrasonic
`blind spot detecting system that in fact interrogates as much
`as 200 degrees around the vehicle. It is mounted in place of
`
`the conventional mirror and a new side mirror is provided.
`The ultrasonic sensor rotates until it locates an object and
`then it causes the mirror to rotate so that the driver can see
`
`take an image of the
`the object. The patent does not
`threatening object or the object in blind spot. It is a one-pixel
`device and it does not employ pattern recognition. Addi-
`tionally, it provides too much information for the driver thus
`creating the possibility of driver information overload.
`
`[0039] US. Pat. No. 5,289,321 describes a camera and an
`LCD display on the instrument panel. The camera views
`rearward and driver sees the image captured on an LCD. It
`does not disclose the camera mounted on the rear view
`
`mirror. The main problem is that the LCD driver-viewing
`screen is more likely to confuse than to aid the driver due to
`its poor dynamic light intensity range and the ability to relate
`the image to the location and velocity of the object in the
`blind spot.
`
`[0040] US. Pat. No. 5,291,261 describes illumination
`ports at an angle with respect to single pixel receiver ports.
`Fiber optics are used to transmit the few pixels to a central
`processing station. There is no direct ranging. Some crude
`ranging is accomplished since when the object is in certain
`zones where the projected light overlays the receiving fields,
`the reflected light can be sensed. It requires multiple loca-
`tions and cannot be mounted, for example, on the side
`rearview mirror.
`
`[0041] US. Pat. No. 5,325,096 uses Doppler radar to
`determine the presence and relative velocity of an object
`blind spot. It filters out stationary objects and concentrates
`only on those objects that have approximately the same
`velocity as the vehicle. As a result, many objects, such as a
`high speed passing vehicle, are missed. A light is used to
`indicate the presence of an occupying item in the blind spot
`area and an audible alarm is sounded when the turn signal is
`activated. There is some crude range measurement possible.
`It is also a single pixel device and thus, no image of the
`object can be formed. It invariably will miss objects that
`move rapidly into blind spot. There is no precise ranging. It
`does not appear that the system can be easily adjusted for
`vehicles of different length.
`
`[0042] US. Pat. No. 5,517,196 describes a multi-fre-
`quency radar system using Doppler techniques. Stationary
`objects are filtered out. In fact, the system also only looks at
`objects that are traveling at approximately the same speed as
`the host vehicle. It has a good range of 0.25 to 100 feet.
`Some problems are that this system will interfere with other
`vehicles having the same system. There appears to be no
`direct measurement of the object’s position, but it does give
`a good distance resolution of 0.55 feet. This patent also
`contemplates the use of steering wheel angle and vehicle
`speed inputs to the system. Even though ultrasonic, infrared
`and radar are disclosed, it is still a single pixel system. Once
`again, the system will invariably miss a high-speed vehicle
`passing on either the right or the left since it is limited to a
`two mile per hour velocity difference between the blind spot
`object and the host vehicle. It also appears to be a very
`expensive system. Another potential problem is that when an
`especially long truck having the system of this patent is
`turning, the system would pick up the end of truck and treat
`it as they object in the blind spot.
`
`[0043] US. Pat. No. 5,424,952 describes an optical sys-
`tem using cameras wherein distance is measured stereo-
`
`

`

`US 2002/0005778 A1
`
`Jan. 17, 2002
`
`scopically. Objects that are not in the adjacent lane are
`ignored. The problems are that no attempt is made to analyze
`the image or to determine its velocity and therefore, a high
`false alarm rate can be expected. Although the image is
`captured, the information is ignored except for its use to
`determine a stereo distance.
`
`[0044] US. Pat. No. 5,467,072 describes a phased array
`radar system that can scan the blind spot as well as all other
`areas around vehicle. However, the system does not provide
`an image and therefore no pattern recognition is possible.
`The 10 degree divergence angle of radar indicates that a
`single pixel has a diameter of over 3 feet at 20 feet from the
`radar transmitter which is insufficient resolution to deter-
`
`mine the lane that the threatening vehicle is occupying,
`especially if there is a slight curvature in the road. Such a
`system is not sufficiently accurate to provide drivers who are
`attempting to merge into adjacent lines with sufficiently
`accurate position information to permit a safe merge under
`heavy traffic without visual contact. Additionally, there is no
`pattern recognition claimed or even possible with this low
`resolution device.
`
`[0045] US. Pat. No. 5,668,539 uses thermal imaging to
`recognize a car or truck the blind spot. It uses a vibrating
`element between the field of view containing the blind spot
`using three lenses thus giving three different locations and a
`reference field of view that is the road behind the vehicle.
`
`The problems with this device are that this system does not
`know where the infrared rays are coming from. It could be
`from the sun or from reflections from the wrong lane. The
`slow cycle time prevents averaging to eliminate errors. At a
`60 km per hour passing rate, the vehicle will travel 1.7 In
`each cycle based on a 10 hertz cycle rate. The patent also
`mentions that the form of the signal that comes from a
`vehicle and the blind spot has high frequency associated
`with it whereas the form of the signal from the road does not.
`This is an alternate method of discriminating between a
`vehicle and the road but one that still lacks resolution.
`
`[0046] US. Pat. No. 5,670,935 describes a camera and a
`display where the actual images of the vehicle in the blind
`spot and behind the subject vehicle are displayed on the
`visual display. Unfortunately,
`the various figures in the
`patent that illustrate this phenomena are not accurate and
`appear to show that the positions of the vehicles relative to
`the subject vehicle can be visually seen which is not the case.
`Thus, the invention described in this patent cannot be used
`for blind spot detection in the manner that is described in this
`patent since the relative locations of vehicles cannot be
`determined. Also, no attempt has been made to identify and
`analyze objects in the blind spot and warn the driver of a
`pending accident.
`
`[0047] US. Pat. No. 5,765,116 describes a system wherein
`a torque is artificially applied to the steering wheel to keep
`a driver in the center of his lane. This is not a blind spot
`related patent but this same technique can be used to prevent
`a driver from attempting to change lanes when there is an
`object
`in the blind spot and thus is applicable to this
`invention.
`
`[0048] US. Pat. No. 6,038,496 describes a lane boundary
`finder. It uses a linear array of LEDs plus a linear CCD with
`a total of 64 pixels in the CCD array. It can be used for blind
`spot monitoring, although this is not the main purpose of this
`invention. The CCD array suffers from the problem that, due
`
`to its limited dynamic range, it can be overwhelmed by light
`from the sun, for example, reflected off a vehicle or other
`surface. Since there is only a linear array of only 64 pixels,
`no information as to what
`is in the blind spot can be
`obtained. In other words, the system knows that something
`is in the blind spot but does not know what it is or even
`accurately where it is. Nevertheless, the use of the scanning
`system disclosed wherein the particular pixel or the beam
`that is being activated to create a light on a leading or
`reflecting surface is an important addition to the technology
`and may also be used with this invention.
`
`International Publication No. WO 95/25322
`[0049]
`describes a passive infrared blind spot detector that pro-
`cesses infrared waves based on a crude form of pattern
`recognition. There is no accurate ranging and there will
`likely be a high false alarm rate with this system. There is
`also sometimes a period when the system is unavailable due
`to changes in ambient conditions such as the start of a rain
`shower or when the temperature of the road changes due to
`shading. It
`is a one-pixel device and therefore does not
`permit the location of the object in the blind spot to be
`determined. This device and other similar passive infrared
`devices will have trouble distinguishing between a small
`objects such as a motorcycle which is relatively close to the
`sensor and larger objects such as a truck which are relatively
`far away, for example in two lanes over. As a result, it will
`likely falsely indicate that a relatively large object is within
`a danger zone when in reality the object is at a distance
`which does not pose a threat.
`
`International Publication No, WO 99/42856
`[0050]
`describes a rear of vehicle mounted blind spot detector based
`on various radar systems. It has the capability of tracking
`multiple targets and of accurately determining the ranges to
`the various targets using range-gating techniques. It does not
`attempt to capture an image of an object in the blind spot or
`determine the identity of such an object and thus many
`non-threatening objects will appear
`to be threatening.
`Accordingly, the system can be expected to have a high false
`alarm rate.
`
`In general, the poor resolution of radar systems
`[0051]
`requires that they use relative velocity as a filter in order to
`reduce the false alarm rate. As a result, such systems miss a
`high speed vehicle which is in the blind spot and was not
`observed approaching the blind spot by the driver. This is a
`very common occurrence on European superhighways and
`in the United States on two lane roads.
`
`[0052] Thus, none of the prior art described above dis-
`closes a method or apparatus of monitoring the blind spot of
`the vehicle that analyzes an image of one or more objects
`that occupy the blind spot, identifying them and determining
`the location and relative velocity of the objects relative to the
`host vehicle in a manner that permits an accurate warning to
`be issued to the driver of a potentially dangerous situation.
`
`[0053]
`
`2. Definitions
`
`invention are
`the
`[0054] Preferred embodiments of
`described below and unless specifically noted,
`it
`is the
`applicants’
`intention that
`the words and phrases in the
`specification and claims be given the ordinary and accus-
`tomed meaning to those of ordinary skill in the applicable
`art(s). If the applicants intends any other meaning, they will
`specifically state they are applying a special meaning to a
`word or phrase.
`
`

`

`US 2002/0005778 A1
`
`Jan. 17, 2002
`
`[0055] Likewise, applicants’ use of the word “function”
`here is not intended to indicate that the applicants seek to
`invoke the special provisions of 35 U.S.C. §112, sixth
`paragraph,
`to define their invention. To the contrary,
`if
`applicants wish to invoke the provisions of 35 U.S.C.§112,
`sixth paragraph, to define their invention, they will specifi-
`cally set forth in the claims the phrases “means for” or “step
`for” and a function, without also reciting in that phrase any
`structure, material or act in support of the function. More-
`over, even if applicants invoke the provisions of 35 U.S.C.
`§112, sixth paragraph, to define their invention, it is the
`applicants’ intention that their inventions not be limited to
`the specific structure, material or acts that are described in
`the preferred embodiments herein. Rather,
`if applicants
`claim their inventions by specifically invoking the provi-
`sions of 35 U.S.C. §112, sixth paragraph, it is nonetheless
`their intention to cover and include any and all structure,
`materials or acts that perform the claimed function, along
`with any and all known or
`later developed equivalent
`structures, materials or acts for performing the claimed
`function.
`
`[0056] A “blind spot”, for the purposes of this invention,
`will include those areas surrounding a vehicle that could
`contain an object that may not easily be seen by the driv