U.S. patent application number 12/213443 was filed with the patent office on 2008-10-16 for system for detecting an empty vehicle seat.
This patent application is currently assigned to TK HOLDINGS INC.. Invention is credited to James G. Stanley.
Application Number | 20080252465 12/213443 |
Document ID | / |
Family ID | 37102420 |
Filed Date | 2008-10-16 |
United States Patent
Application |
20080252465 |
Kind Code |
A1 |
Stanley; James G. |
October 16, 2008 |
System for detecting an empty vehicle seat
Abstract
A system for detecting an empty vehicle seat includes an emitter
mounted in the vehicle seat and a sensor for detecting changes in
radiation produced by the emitter, wherein the changes in radiation
may indicate whether an object is in the vehicle seat. A heater may
be mounted in the vehicle seat. A sensor, positioned above the
vehicle seat, may detect changes in the surface temperature of the
vehicle seat. The changes in surface temperature may indicate
whether an object is in the vehicle seat. A light source may be
mounted in the vehicle seat. A sensor, positioned above the vehicle
seat, detects changes in the light produced by the light source.
The changes in the produced light indicate whether an object is in
the vehicle seat.
Inventors: |
Stanley; James G.; (Novi,
MI) |
Correspondence
Address: |
FOLEY AND LARDNER LLP;SUITE 500
3000 K STREET NW
WASHINGTON
DC
20007
US
|
Assignee: |
TK HOLDINGS INC.
|
Family ID: |
37102420 |
Appl. No.: |
12/213443 |
Filed: |
June 19, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11498811 |
Aug 4, 2006 |
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12213443 |
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60705465 |
Aug 5, 2005 |
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Current U.S.
Class: |
340/573.1 |
Current CPC
Class: |
B60R 21/01534 20141001;
B60N 2/002 20130101; B60R 21/01556 20141001; B60R 21/0154
20141001 |
Class at
Publication: |
340/573.1 |
International
Class: |
G08B 21/22 20060101
G08B021/22 |
Claims
1. A system for detecting an empty vehicle seat, comprising: a
heater mounted in the vehicle seat; a sensor, positioned above the
vehicle seat, for detecting changes in the surface temperature of
the vehicle seat; and a controller configured to receive an input
from the sensor and to determine whether an object is in the
vehicle seat based on the changes in the surface temperature of the
vehicle.
2. A system for detecting an empty vehicle seat as claimed in claim
1, wherein the heater is mounted in a seat bottom of the vehicle
seat.
3. A system for detecting an empty vehicle seat as claimed in claim
1, wherein the heater is mounted in a seat back of the vehicle
seat.
4. A system for detecting an empty vehicle seat as claimed in claim
1, wherein the sensor is an infrared sensor configured to measure
the intensity of infrared electromagnetic waves produced by the
heater to determine the surface temperature of the vehicle seat.
Description
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS
[0001] This application is a divisional application of U.S.
application Ser. No. 11/498,811 and also claims priority to and
benefit of U.S. Provisional Application No. 60/705,465, filed Aug.
5, 2005, the disclosure of which is incorporated herein by
reference in its entirety.
BACKGROUND
[0002] The present invention relates generally to the field of
occupant detection. Specifically, the present invention is directed
to a system and method of identifying whether a passenger seat is
empty, or whether an object or occupant is in the seat. The
occupant, for example, could be a person seated directly on the
seat or a child in a child seat.
[0003] There are many existing systems that employ sensors to
detect and classify an occupant located in a passenger seat of a
vehicle. Weight sensors, vision sensors, pressure sensors,
capacitive sensors are examples of some devices that may be used in
occupant detection systems.
[0004] The general objective of the classification systems
described above, is to determine whether there is an occupant
present in a vehicle seat. In turn, information collected by the
sensors may be used by a vehicle safety restraint system to
determine whether to activate certain devices to protect actual
vehicle occupants. Alternatively, the information collected by the
sensors could be used to warn occupants that their seat belt is not
buckled. In addition, the system described above could be used to
identify occupant presence in the front passenger positions or in
the passenger positions in seating rows rear of the driver.
[0005] Generally, conventional systems do not produce consistent
results. These systems have difficulty consistently identifying and
accurately monitoring empty seat conditions. For example, typical
systems have difficulty discerning an empty seat from a seat that
is occupied by a child seat.
[0006] Measurement based on the vertical force applied on a vehicle
seat may also produce inconsistent results because an occupied
child seat may cause the pressure distribution and total force on
the seat to be very low. As a result, it may be difficult to
discern whether an occupant is present in the vehicle seat (e.g., a
10 pound child in an 8 pound child seat spread across much of the
seat bottom).
[0007] Thus, a more sensitive system for detecting the presence of
an object or occupant in a vehicle seat is needed.
SUMMARY OF THE INVENTION
[0008] According to one embodiment of the invention, a system for
detecting an empty vehicle seat includes an emitter mounted in the
vehicle seat, a sensor for detecting changes in radiation produced
by the emitter and a controller configured to receive an input from
the sensor and to determine whether an object is in the vehicle
seat.
[0009] According to another embodiment of the invention, the
emitter is configured to emit electromagnetic radiation. The
emitter may be mounted in a seat bottom of the vehicle seat or in a
seat back of the vehicle seat.
[0010] According to yet another embodiment of the invention, the
sensor is configured to monitor at least a seat bottom of a vehicle
seat. Alternatively, the sensor is configured to monitor a seat
bottom and seat back of a vehicle seat. The sensor may be
positioned on an A-pillar or B-pillar inside the vehicle.
Alternatively, the sensor is positioned on the instrument panel
located inside the vehicle or on the ceiling of the vehicle.
[0011] According to still another embodiment of the invention, the
sensor monitors changes in radiation on the vehicle seat when the
emitter is turned on. The sensor is configured to measure the
intensity of the electromagnetic radiation produced by the
emitter.
[0012] According to one embodiment of the invention, a system for
detecting an empty vehicle seat includes a heater mounted in the
vehicle seat, a sensor, positioned above the vehicle seat, for
detecting changes in the surface temperature of the vehicle seat
and a controller configured to receive an input from the sensor and
to determine whether an object is in the vehicle seat.
[0013] According to another embodiment of the invention, the heater
is mounted in a seat bottom of the vehicle seat. Alternatively, the
heater is mounted in a seat back of the vehicle seat.
[0014] According to yet another embodiment of the invention, the
sensor is an infrared sensor configured to measure the intensity of
infrared electromagnetic waves produced by the heater to determine
the surface temperature of the vehicle seat. The sensor monitors
changes in the surface temperature of the vehicle seat when the
heater is turned on.
[0015] According to still another embodiment of the invention, a
system for detecting an empty vehicle seat includes a light source
mounted in a vehicle seat, a sensor, positioned above the vehicle
seat, for detecting the light produced by the light source and a
controller configured to receive an input from the sensor and to
determine whether an object is in the vehicle seat.
[0016] According to one embodiment of the invention, the light
source is mounted in a seat back of the vehicle seat and the sensor
is positioned such that the light from the source is incident upon
the sensor. Alternatively, the light source is mounted in a seat
bottom of the vehicle seat or on the surface of the seat bottom of
the vehicle seat.
[0017] The sensor monitors the light on the vehicle seat when the
light source is turned on and is configured to measure the
intensity of light produced by the light source.
[0018] It is to be understood that both the foregoing general
description and the following detailed description are exemplary
and explanatory only, and are not restrictive of the invention as
claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] These and other features, aspects and advantages of the
present invention will become apparent from the following
description, appended claims, and the accompanying exemplary
embodiments shown in the drawings, which are briefly described
below.
[0020] FIG. 1 is a profile view of a system for detecting an empty
vehicle seat according to one embodiment of the invention.
[0021] FIG. 2 is a profile view of a system for detecting an empty
vehicle seat according to another embodiment of the invention.
[0022] FIG. 3 is a perspective view of a emitter mounted in a
vehicle seat according to another embodiment of the invention.
[0023] FIG. 4 is a profile view of a system for detecting an empty
vehicle seat according to one embodiment of the invention.
[0024] FIG. 5 is a profile view of a system for detecting an empty
vehicle seat according to one embodiment of the invention.
[0025] FIG. 6 is a block diagram of a safety restraint system
including a system for detecting an empty vehicle seat according to
one embodiment of the invention.
[0026] FIG. 7 is a profile view of a system for detecting an empty
vehicle seat according to another embodiment of the invention.
DETAILED DESCRIPTION
[0027] Embodiments of the present invention will be described below
with reference to the accompanying drawings. It should be
understood that the following description is intended to describe
exemplary embodiments of the invention, and not to limit the
invention.
[0028] FIG. 1 shows a system for detecting an empty vehicle seat 1
according to one embodiment of the invention. An emitter 10 is
positioned in the vehicle seat 20. A sensor 30 is disposed inside
the vehicle and is configured to monitor the output of the emitter
10.
[0029] As shown in FIG. 1, the emitter 10 is positioned in the seat
bottom of the vehicle seat 20. Alternatively, the emitter 10 may be
positioned in the seat back of the vehicle seat 20. According to
one embodiment of the invention, the emitter 10 may be positioned
on the surface of the seat bottom or the surface of the seat back
of the vehicle seat 20. The sensor 30 may also be positioned at
numerous locations. For example, the sensor 30 may be positioned in
the vehicle instrument panel, on the vehicle pillars, or on the
vehicle ceiling in order to monitor emissions from an emitter
mounted in the seat back.
[0030] The emitter 10 is a device that is capable of producing and
emitting electromagnetic radiation that may be detected by a sensor
30. The emitter 10 may generate electromagnetic radiation at a
constant rate or the emitter 10 may generate radiation in pulses.
Further, the electromagnetic radiation generated by the emitter 10
has properties such that the electromagnetic radiation is greatly
attenuated when an object is in its path. The emitter 10 may
generate electromagnetic radiation undetectable to the human eye
such as, for example, infrared waves. Alternatively, the
electromagnetic radiation may be visible light or ultra violet
light.
[0031] According to one embodiment of the invention, the emitter 10
is a heater for heating the vehicle seat 20. When operational, the
heater generates infrared waves that may be detected by the sensor
30.
[0032] According to still another embodiment of the invention, the
emitter 10 is a light source configured to produce light that may
be detected by the sensor 30. Accordingly, if enough light is
generated under the cover of the vehicle seat 20, some of the light
will penetrate the seat cover and may be detected from above the
vehicle seat 20. In certain embodiments, the light source may be
located under the seat foam of the seat bottom or the seat
back.
[0033] In a situation where the seat cover attenuates the emitted
light by a large amount, it is possible to put the emitter 10
(light source) in a location in the vehicle seat 20 where there is
a seam between sections of the vehicle seat 20 such that the light
passes through the vehicle seat 20. Alternatively, according to one
embodiment of the invention, the vehicle seat 20 includes an area
comprising a material configured to allow at least a detectable
amount of visible light to pass through the surface of the vehicle
seat 20.
[0034] According to another embodiment of the invention, fiber
optics are woven into the seat cover. When light is emitted down
the fiber, some light escapes the fiber (by design of the fiber and
the fiber's bend radius) and is visible from above the vehicle seat
20. Alternatively, as shown in FIG. 3, an emitter 10 (light source)
may be placed in line with the "trench" 25 of the seat foam. The
"trench" 25 is where the seat cover is held to the seat foam.
Trenches 25 may be positioned on the bottom of the seat or the seat
back.
[0035] As shown in FIGS. 1 and 2, the sensor 30 may be positioned
above the vehicle seat 20. The sensor 30 detects the intensity and
fluctuations of the electromagnetic radiation produced by the
emitter 10. According to one embodiment of the present invention,
the sensor 30 is configured to monitor an area encompassing the
majority of the seat bottom of the vehicle seat 20. Thus, as shown
in FIG. 1, the scanning area of the sensor 30 is large enough to
monitor the seat bottom of the vehicle seat 20 in the full range of
positions that the vehicle seat 20 may assume. According to another
embodiment of the invention, the sensor 30 is configured to monitor
the seat back of the vehicle seat 20 in addition to the vehicle
seat bottom.
[0036] The sensor 30 may be positioned at any suitable location in
the vehicle. The sensor 30 should be positioned facing the emitter
10 in a location where the sensor's scanning area is not obstructed
by other vehicle components. According to one embodiment of the
invention, the sensor 30 is positioned on an A-pillar inside the
vehicle. According to another embodiment of the invention, the
sensor 30 is positioned on an instrument panel located inside the
vehicle. According to still another embodiment of the invention,
the sensor 30 is positioned on the ceiling of the vehicle.
[0037] According to another embodiment of the invention, the system
is used to identify occupant presence in the rear seats, wherein a
single sensor 30 is used to monitor the emitters 10 in multiple
seating locations. The sensor 30 could be mounted on the pillars,
on the ceiling, or on any other location where there is no
obstruction in the vehicle between the emitter 10 and sensor
30.
[0038] The operation of an exemplary system, will now be described
with reference to FIGS. 2-6.
[0039] FIG. 6 is a block diagram of a safety restraint system
including a system for detecting an empty vehicle seat. A
controller 50 is provided. The controller is operably connected to
the sensor 30 and emitter 10. The controller 50 operates the
emitter 10 and receives information in the form of signals from the
sensor 30. The controller 50 is also connected to a restraint
control module (RCM) 60. The RCM 60 is operably connected to an
airbag 70 and a pretensioner 80. The RCM 60 is configured to
control the operation of the airbag 70 and pretensioner 80.
Specifically, the RCM 60 may determine whether the airbag 70 and
pretensioner 80 can be activated based on the signals received by
the controller 50 from the sensor 30. According to one embodiment
of the invention, the controller 50 may also function as the RCM
60.
[0040] During operation, the controller 50 controls the heater 10
in the seat bottom and monitors changes in the vehicle seat's 20
temperature when the heater 10 is turned on. Specifically, the
sensor 30 is configured to detect changes in the intensity of
electromagnetic radiation emitted from the seat region. The output
from the sensor 30 can be used by the controller 50 to calculate or
derive an increase or decrease in temperature of the vehicle seat
20.
[0041] The emitter 10 is a heater, and when the vehicle seat 20 is
completely empty, the sensor 30 will detect a change in temperature
of the seating surface when the heater 10 is operating. In
contrast, when a significant object is positioned on the seating
surface, the sensor 30 will only be able to monitor, view and/or
detect characteristics of the surface of the object. When the
sensor 30 is configured to monitor temperature change, the sensor
may be configured so that the sensor 30 will not detect a drastic
temperature change even though the heater 10 is operating. A
detection of a minor or insignificant change in temperature when
the heater 10 is turned on indicates to the system 1 that an object
is present on the vehicle seat 20.
[0042] For example, according to one embodiment of the invention
and as shown in FIG. 2, if there is a child seat 40 on the vehicle
seat 20, the sensor 30 will measure the temperature on the surface
of the child seat 40 facing the sensor 30. Typically, while the
seat bottom is warming up, the temperature at the surface of the
child seat 40 facing the sensor 30 will not change significantly.
The failure of the sensor to detect a change in temperature
indicates that an object may be present on the vehicle seat 20. If,
on the other hand, the sensor 30 detects a change in the seat
surface temperature when the seat heater 10 is operating, then an
empty seat is indicated.
[0043] The sensor 30 may also measure the temperature when the
heater 10 is not operating. An empty seat will usually cool after
the seat heater is turned off and the sensor 30 will detect a
temperature reduction. According to one embodiment of the
invention, the controller 50 may monitor numerous heating or
cooling cycles in order to confirm the occupant's presence.
[0044] According to another embodiment of the invention and as
shown in FIG. 7, fluorescent material 100 is placed on the seat
bottom 20 or the seat back 125. A light source is positioned above
the seat and is configured to cause the seat bottom 120 or seat
back 125 to fluoresce when turned on. The light source may have a
wavelength corresponding to infra red light, ultra violet light or
visible light. Similarly, the fluorescent material may fluoresce at
a wavelength corresponding to infra red light, ultra violet light
or visible light. The sensor 130, mounted above the vehicle seat
120, is configured to detect light being emitted from the
fluorescent material 100 to determine whether the vehicle seat is
empty.
[0045] According to certain aspects of the invention, several
advantages may be realized. According to one embodiment of the
invention, a seat heater in the seat bottom (or seat back) is a
source of radiation that may be used to identify whether there is
an occupant in the vehicle seat 20. The system is very effective
for the occupant classification categories which are the most
difficult to detect such as light child seats. Other conventional
systems may use the heat from the occupant to identify when the
seat is occupied, but these conventional systems are prone to
erroneous readings when the occupants are wearing thick clothing,
or when there is a child seat that is covered with a blanket. In
addition, for existing IR systems, the contrast for passive IR
imaging sensors is reduced when the ambient temperature is between
30 degrees Celsius and 40 degrees Celsius. An important advantage
of the system disclosed herein is that the system uses a change in
electromagnetic radiation being emitted from the seat surface as an
indicator of whether the seat is empty. Thus, in the disclosed
system the temperature and weight of the occupant are not
significant factors in occupant detection.
[0046] The foregoing description of a preferred embodiment of the
invention has been presented for purposes of illustration and
description. It is not intended to be exhaustive or to limit the
invention to the precise form disclosed, and modifications and
variations are possible in light of the above teaching or may be
acquired from practice of the invention. The embodiment was chosen
and described in order to explain the principles of the invention
and as a practical application to enable one skilled in the art to
utilize the invention in various embodiments and with various
modification are suited to the particular use contemplated. It is
intended that the scope of the invention be defined by the claims
appended hereto and their equivalents.
* * * * *