U.S. patent application number 11/146927 was filed with the patent office on 2005-12-22 for child seat and monitoring system.
Invention is credited to Fortune, Duane D., Fultz, William W., Kincaid, Kevin D., Lawrence, Rodney A., Patterson, James F., Porter, Stephen B., Sullivan, Stuart S., Wallner, Edward J..
Application Number | 20050280297 11/146927 |
Document ID | / |
Family ID | 35503698 |
Filed Date | 2005-12-22 |
United States Patent
Application |
20050280297 |
Kind Code |
A1 |
Patterson, James F. ; et
al. |
December 22, 2005 |
Child seat and monitoring system
Abstract
A child seat adapted for use in a vehicle, the child seat
comprising: a shell portion configured for use with or without a
base portion; at least one an adjustable tether secured to the
shell portion at one end and having a clasping portion at the
other; a tension sensor for providing a signal indicative of a
tension of the adjustable tether; and an electronic control unit
secured to the shell portion, the electronic control unit being
operably coupled to the tension sensor to receive the signal, the
electronic control unit being capable of processing the signal to
compare the signal to a signal indicative of a predetermined range
of acceptable tension, wherein the electronic control unit provides
an output indicating whether the tension of the adjustable tether
is within the predetermined range.
Inventors: |
Patterson, James F.;
(Greentown, IN) ; Sullivan, Stuart S.; (Peru,
IN) ; Lawrence, Rodney A.; (Frankfort, IN) ;
Fortune, Duane D.; (Lebanon, IN) ; Wallner, Edward
J.; (Westfield, IN) ; Porter, Stephen B.;
(Noblesville, IN) ; Fultz, William W.; (Carmel,
IN) ; Kincaid, Kevin D.; (Kokomo, IN) |
Correspondence
Address: |
DELPHI TECHNOLOGIES, INC.
M/C 480-410-202
PO BOX 5052
TROY
MI
48007
US
|
Family ID: |
35503698 |
Appl. No.: |
11/146927 |
Filed: |
June 6, 2005 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
60577546 |
Jun 7, 2004 |
|
|
|
60607988 |
Sep 8, 2004 |
|
|
|
Current U.S.
Class: |
297/217.4 ;
297/217.3 |
Current CPC
Class: |
B60N 2/2809 20130101;
B60N 2/2824 20130101; B60N 2002/2815 20130101; B60N 2/2863
20130101; B60N 2/2875 20130101; B60N 2002/0272 20130101; B60N
2/2806 20130101; B60N 2/002 20130101; B60N 2/2845 20130101; B60N
2/2887 20130101; B60N 2/2842 20130101; B60N 2/286 20130101; B60N
2/2812 20130101; B60N 2/2821 20130101; B60N 2/2881 20130101; B60N
2/0244 20130101 |
Class at
Publication: |
297/217.4 ;
297/217.3 |
International
Class: |
A47C 031/00 |
Claims
What is claimed is:
1. A child seat adapted for use in a vehicle, the child seat
comprising: a shell portion; an adjustable tether secured to the
shell portion at one end and having a clasping portion at the
other, a tension sensor for providing a signal indicative of a
tension of the adjustable tether; and an electronic control unit
secured to the shell portion, the electronic control unit being
operably coupled to the tension sensor to receive the signal, the
electronic control unit being capable of processing the signal to
compare the signal to a signal indicative of a predetermined range
of acceptable tension, wherein the electronic control unit provides
an output indicating whether the tension of the adjustable tether
is within the predetermined range.
2. The child seat as in claim 1, wherein the electronic control
unit further comprises a display integrally formed with the shell
portion and the output of the electronic control unit is an LED
disposed on the display.
3. The child seat as in claim 1, wherein the electronic control
unit further comprises a liquid crystal display and the output of
the electronic control unit is indicia disposed on the display.
4. The child seat as in claim 1, wherein the output is an audible
chime if the tension of the adjustable tether is not within the
predetermined range.
5. The child seat as in claim 1, wherein the output is audible text
if the tension of the adjustable tether is not within the
predetermined range.
6. The child seat as in claim 1, wherein the tension sensor is
located at a point of securement between the adjustable tether and
the child seat and the child seat is a booster seat.
7. The child seat as in claim 6, wherein the tension sensor
comprises at least one magnet and a Hall effect device positioned
to detect the presence of a magnetic field of the at least one
magnet.
8. The child seat as in claim 1, wherein the tension sensor is
embedded into the adjustable tether.
9. The child seat as in claim 1, wherein the child seat is
configured to restrain children having a weight less than
approximately 22 pounds.
10. The child seat as in claim 1, wherein the adjustable tether is
secured to an upper portion of the shell portion and the child seat
further comprises: a lower adjustable tether secured to a lower
portion of the shell portion at one end and having a clasping
portion at the other; a tension sensor for providing a signal
indicative of a tension of the lower adjustable tether; wherein the
electronic control unit is operably coupled to the tension sensor
to receive the signal of the lower adjustable tether, the control
unit being capable of processing the signal to compare the signal
to a signal indicative of a predetermined range of acceptable
tension for the lower adjustable tether, wherein the electronic
control unit provides another output indicating whether the tension
of the lower adjustable tether is within the predetermined
range.
11. The child seat as in claim 10, wherein the electronic control
unit further comprises a display and the output and the another
output of the electronic control unit each comprise an LED disposed
on the display.
12. The child seat as in claim 11, wherein the electronic control
unit further comprises a liquid crystal display and the output and
the another output of the electronic control unit is indicia
disposed on the display.
13. The child seat as in claim 11, wherein the output and the
another output is an audible chime if the tension of the lower
adjustable tether or the adjustable tether is not within the
predetermined range.
14. The child seat as in claim 11, wherein the output and the
another output is audible text if the tension of the lower
adjustable tether or the adjustable tether is not within the
predetermined range.
15. The child seat as in claim 11, wherein the lower adjustable
tether is rigid member secured and the tension sensor of the lower
adjustable member comprises at least one magnet and a Hall effect
device positioned to detect the presence of a magnetic field of the
at least one magnet.
16. The child seat as in claim 1, wherein the adjustable tether is
secured to an upper portion of the shell portion and the child seat
further comprises: a pair of lower adjustable tethers each being
secured to a lower portion of the shell portion at one end and
having a clasping portion at the other, wherein one of the pair of
lower adjustable tethers are secured to one side of the shell and
the other is secured to another side of the shell; a tension sensor
for each of the pair of lower adjustable tethers each providing a
signal indicative of a tension in one of the pair of the lower
adjustable tethers; wherein the electronic control unit is operably
coupled to the tension sensors to receive the signals of the pair
of lower adjustable tethers, the control unit being capable of
processing the signals to compare the signals to a signal
indicative of a predetermined range of acceptable tension for each
of pair of lower adjustable tethers, wherein the electronic control
unit provides another output indicating whether the tension of the
pair of lower adjustable tethers is within the predetermined
range.
17. The child seat as in claim 16, wherein the electronic control
unit further comprises a display integrally formed with the shell
portion and the output and the another output of the electronic
control unit is an LED disposed on the display.
18. The child seat as in claim 16, wherein the output and the
another output is an audible chime or audible text if the tension
of the adjustable tether or the tension of the pair of lower
adjustable tethers is not within the predetermined range.
19. A child restraint system adapted for use in a vehicle,
comprising: a child seat having a shell portion; an adjustable
tether secured to the shell portion at one end and having a
clasping portion at the other, a tension sensor for providing a
signal indicative of a tension of the adjustable tether; an
electronic control unit secured to the child seat, the electronic
control unit being operably coupled to the tension sensor to
receive the signal, the electronic control unit being capable of
processing the signal to compare the signal to a signal indicative
of a predetermined range of acceptable tension, wherein the
electronic control unit provides an output indicating whether the
tension of the adjustable tether is within the predetermined range,
wherein the electronic control unit is also operably coupled to a
plurality of sensors each providing additional signals indicative
of states of the child seat to the electronic control unit and the
electronic control unit is capable of processing the additional
signals to compare the additional signals to acceptable values,
wherein the electronic control unit provides additional outputs
indicating whether the additional signals are at acceptable
values.
20. The child restraint system as in claim 19, wherein the
electronic control unit further comprises a display integrally
formed with the shell portion and the output of the electronic
control unit is an LED disposed on the display and the additional
outputs are additional LEDs disposed on the display.
21. The child restraint system as in claim 20, wherein the
adjustable tether is secured to an upper portion of the shell
portion and the child seat further comprises: a lower adjustable
tether secured to a lower portion of the shell portion at one end
and having a clasping portion at the other; a tension sensor for
providing a signal indicative of a tension of the lower adjustable
tether; wherein the electronic control unit is operably coupled to
the tension sensor to receive the signal of the lower adjustable
tether, the control unit being capable of processing the signal to
compare the signal to a signal indicative of a predetermined range
of acceptable tension for the lower adjustable tether, wherein the
electronic control unit provides another output indicating whether
the tension of the lower adjustable tether is within the
predetermined range.
22. The child restraint system as in claim 21, wherein the
plurality of additional sensors are selected from the group
comprising: weight sensors, accelerometers, seat belt tension
sensors, seat belt latch sensors, force sensors,
23. A method for determining if the tension of an adjustable tether
of a child seat is within an acceptable range, the method
comprising: locating a tension sensor along a portion of the
adjustable tether, wherein the tension sensor is configured to
provide a signal indicative of a tension of the adjustable tether;
receiving the signal of the tension sensor by an electronic control
unit being operably coupled to the tension sensor and secured to a
portion of the child seat; processing the signal to determine if
the signal corresponds to a predetermined range of acceptable
tension; and indicating whether the tension of the adjustable
tether is within the predetermined range by providing an
output.
24. The method as in claim 23, wherein the output is in the form of
an illuminated display on a visible surface of the electronic
control unit and wherein the signal is an analog signal.
25. A child seat adapted for use in a vehicle, the child seat
comprising: a base portion; a carrier portion configured to
restrain a child the carrier portion being removable secured to the
base portion; an adjustable tether secured to the base portion
having a pair of clasping portions disposed at either end, a
tension sensor for providing a signal indicative of a tension of
the adjustable tether; and an electronic control unit secured to
either the base portion or the carrier portion, the electronic
control unit being operably coupled to the tension sensor to
receive the signal, the control unit being capable of processing
the signal to compare the signal to a signal indicative of a
predetermined range of acceptable tension, wherein the electronic
control unit provides an output indicating whether the tension of
the adjustable tether is within the predetermined range.
26. The child seat adapted as in claim 25, wherein the electronic
control unit is disposed in a cavity of either the base portion or
the carrier portion.
27. A rear facing child seat adapted for use in a vehicle, the rear
facing child seat comprising: a shell portion configured to
restrain a child; an adjustable tether secured to the shell portion
having a pair of clasping portions disposed at either end; a
tension sensor for providing a signal indicative of a tension of
the adjustable tether; and an electronic control unit secured to
the shell portion, the electronic control unit being operably
coupled to the tension sensor to receive the signal, the control
unit being capable of processing the signal to compare the signal
to a signal indicative of a predetermined range of acceptable
tension, wherein the electronic control unit provides an output
indicating whether the tension of the adjustable tether is within
the predetermined range.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The application claims the benefit of U.S. Provisional
application, Ser. No. 60/577,546, filed Jun. 7, 2004, the contents
of which are incorporated herein by reference thereto.
[0002] The application also claims the benefit of U.S. Provisional
application, Ser. No. 60/607,988, filed Sep. 8, 2004, the contents
of which are incorporated herein by reference thereto.
[0003] This application is also related to the following United
States Patent Applications filed contemporaneously herewith: CHILD
SEAT AND MONITORING SYSTEM, Attorney Docket No. DP-312733; CHILD
SEAT MONITORING SYSTEM AND METHOD FOR DETERMINING A TYPE OF CHILD
SEAT, Attorney Docket No. DP-312081; CHILD RESTRAINT SYSTEM AND
METHOD FOR MONITORING INSTALLATION OF THE CHILD RESTRAINT SYSTEM,
Attorney Docket No. 313039; CHILD RESTRAINT SYSTEM AND METHOD FOR
MONITORING INSTALLATION OF THE CHILD RESTRAINT SYSTEM, Attorney
Docket No. DP-312329; CHILD RESTRAINT SYSTEM COMPRISING WEIGHT
SENSOR, Attorney Docket No. DP-312079; CHILD RESTRAINT SYSTEM
COMPRISING CONTROL UNIT FOR EVALUATING HARNESS ADJUSTMENT, Attorney
Docket No. DP-312730. The contents of which are each incorporated
herein by reference thereto.
TECHNICAL FIELD
[0004] This present invention relates generally to child seats and
restraint systems. More specifically, the present invention relates
to a child seat with an apparatus for monitoring the state of a
tether securing the child seat to a vehicle.
BACKGROUND
[0005] Usage of child and/or infant seats in vehicles has become
commonplace and in some situations legally required. Many child
seats are secured to the vehicle by passing a seat belt through an
opening or openings in the child seat, wherein the child seat or
infant seat further comprises a seat belt restraint system for
securing the child to the seat. In addition, some child seats are
equipped with adjustable tethers or straps fixedly secured to the
child seat at one end and comprising a latch at the other end
wherein the latch is clamped or engaged with a universal anchor
point provided in the vehicle. These universal anchors or anchor
points are located throughout the vehicle to provide an anchoring
point for a tethering device or latching device for securing the
child seat to the vehicle. The child seat is securely fastened to
the vehicle when the latch of the tethering device is secured to
the universal anchor and any excess slack is removed such that the
tether has a minimum amount of tension.
[0006] Accordingly, it is desirable to provide a child seat with an
apparatus that will monitor and provide an indication of the amount
of tension in a tether or strap securing the child seat to the
vehicle.
SUMMARY
[0007] Disclosed herein is a device and method for monitoring and
providing an indication of the amount of tension in a tether or
strap securing the child seat to the vehicle.
[0008] In accordance with an exemplary embodiment a child seat
adapted for use in a vehicle is provided. The child seat has a
shell portion; an adjustable tether secured to the shell portion at
one end and having a clasping portion at the other; a tension
sensor for providing a signal indicative of a tension of the
adjustable tether; and an electronic control unit secured to the
shell portion, the electronic control unit being operably coupled
to the tension sensor to receive the signal, the electronic control
unit being capable of processing the signal to compare the signal
to a signal indicative of a predetermined range of acceptable
tension, wherein the electronic control unit provides an output
indicating whether the tension of the adjustable tether is within
the predetermined range.
[0009] A child seat adapted for use in a vehicle, the child seat
comprising: a base portion; a carrier portion configured to
restrain a child the carrier portion being removable secured to the
base portion; an adjustable tether secured to the base portion
having a pair of clasping portions disposed at either end, a
tension sensor for providing a signal indicative of a tension of
the adjustable tether; and an electronic control unit secured to
the base portion, the electronic control unit being operably
coupled to the tension sensor to receive the signal, the control
unit being capable of processing the signal to compare the signal
to a signal indicative of a predetermined range of acceptable
tension, wherein the electronic control unit provides an output
indicating whether the tension of the adjustable tether is within
the predetermined range.
[0010] In accordance with another exemplary embodiment, a method
for determining the tension of an adjustable tether of a child seat
is provided. The method comprising: locating a tension sensor along
a portion of the adjustable tether, wherein the tension sensor is
configured to provide a signal indicative of a tension of the
adjustable tether; receiving the signal of the tension sensor by an
electronic control unit being operably coupled to the tension
sensor and secured to a portion of the child seat; processing the
signal to determine if the signal corresponds to a signal
indicative of a predetermined range of acceptable tension; and
indicating whether the tension of the adjustable tether is within
the predetermined range by providing an output.
[0011] The above-described and other features of the present
disclosure will be appreciated and understood by those skilled in
the art from the following detailed description, drawings, and
appended claims.
DRAWINGS
[0012] FIG. 1 is a side elevational view of a child seat
constructed in accordance with an exemplary embodiment of the
present invention;
[0013] FIG. 2 is a side elevational view of a child seat
constructed in accordance with an alternative exemplary embodiment
of the present invention;
[0014] FIG. 3 is a side elevational view of another child seat
constructed in accordance with an alternative exemplary embodiment
of the present invention;
[0015] FIG. 4 is a schematic illustration of an electronic control
unit constructed in accordance with an exemplary embodiment of the
present invention;
[0016] FIG. 5 is a schematic illustration of a tension sensor
contemplated for use with exemplary embodiments of the present
invention; and
[0017] FIG. 6 is a flow chart illustrating portions of a control
algorithm contemplated for use in exemplary embodiments of the
present invention.
DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0018] Disclosed herein is a method and apparatus for monitoring
and providing an indication of the amount of tension in a tether or
strap securing the child seat to the vehicle. In accordance with an
exemplary embodiment, the tension of the tether is provided to a
control unit of the child seat wherein the control unit comprises
an indicating means for providing a status of the tether tension.
Non-limiting examples of the indicating means includes but are not
limited to visual displays comprising light outputs, visual
displays comprising indicia, audible text, audible chimes or tones
and combinations of any of the foregoing.
[0019] The control unit can also be configured to receive signals
from a plurality of sensors each being adapted to provide
information relative to the child or infant seat to the control
unit wherein the control unit will comprise an algorithm to
interpret and provide an indication means relative to the center
input.
[0020] Referring now to FIGS. 1 and 2, a child seat 10 constructed
in accordance with an exemplary embodiment of the present invention
is illustrated. Child seat 10 is configured to be secured to a seat
12 of a vehicle (not shown) by at least one adjustable securement
tether 14, which is fixedly secured to the child seat at one end
and comprises a latching device 16 at the other. Although only one
adjustable tether is shown in FIG. 1 it is contemplated that
multiple adjustable tethers may be used. In accordance with an
exemplary embodiment, latching device 16 comprises a hook or clasp
18 for securement to at least one universal anchor 20 disposed on
or proximate to the vehicle seat. In accordance with an exemplary
embodiment a lower portion of the child seat is equipped with the
rigid anchor 22 while a top portion is equipped with a tether.
[0021] Referring now to FIG. 2, an alternative child seat has at
least one lower mounting tether or a pair of tethers 24 disposed at
either side to secure a lower portion of the child seat to
universal anchors disposed on either side of the vehicle seat. In
other words a single lower mounting tether or a pair of mounting
tethers are contemplated for use in exemplary embodiments of the
present invention. Referring now to FIG. 3, a rear facing infant
seat 26 is illustrated. Infant seat 26 comprises a carrier portion
28 removably secured to a base portion 30. Base portion 30 is
fixedly secured to the vehicle seat by an adjustable tether 32
comprising a pair of clasping portions 34 (only one shown) disposed
at either end adjustable tether 32 for securement of the same to
the vehicle via universal anchors 20. The base portion is intended
to remain in the vehicle while the carrier portion is intended for
transport of the child in vehicle as well as outside of the vehicle
thereby allowing transport of the infant without waking him or her.
Accordingly, carrier portion 28 securely couples to the base
portion for transporting a child within the vehicle, but may be
disengaged from base portion for carrying the child outside the
vehicle. This infant seat is intended for infants from birth weight
to weights of up to approximately 20-22 pounds or when the baby no
longer fits within the carrier portion. Of course, it is understood
that these ranges are provided as examples and the contemplated
ranges may vary.
[0022] Referring now to FIGS. 1-3 and in accordance with exemplary
embodiments of the present invention each child seat further
comprises an electronic control unit 36. In accordance with an
exemplary embodiment electronic control unit 36 is integral with a
shell portion 38 of child seat 10 or base portion 30.
Alternatively, electronic control unit 36 is configured to be
inserted into a cavity of either the carrier portion or base
portion.
[0023] In accordance with an exemplary embodiment and referring now
to FIGS. 1-4, the electronic control unit will comprise a
microprocessor 40, microcontroller or other equivalent processing
device capable of executing commands of computer readable data or
program for executing a control algorithm that receives signals
from a plurality of sensors 42 and provide an output to a display
44 via visual and/or audio drivers, wherein an indicator 46 of the
electronic control unit is activated. In accordance with an
exemplary embodiment, the electronic control unit is configured to
have analog comparator circuitry for processing analog signals. In
one embodiment analog comparator circuitry is provided as a
stand-alone feature or in combination with other processing
electronics.
[0024] In order to perform the prescribed functions and desired
processing, as well as the computations therefore (e.g., the
execution of fourier analysis algorithm(s), the control processes
prescribed herein, and the like), the electronic control unit may
include, but not be limited to, a processor(s), computer(s),
memory, storage, register(s), timing, interrupt(s), communication
interfaces, and input/output signal interfaces, as well as
combinations comprising at least one of the foregoing. For example,
the controller may include input signal filtering to enable
accurate sampling and conversion or acquisitions of such signals
from communications interfaces. As described above, exemplary
embodiments of the present invention can be implemented through
computer-implemented processes and apparatuses for practicing those
processes.
[0025] In one contemplated embodiment the electronic control unit
is adapted to receive signals transmitted thereto, one non-limiting
example would be wireless radio frequency RF transmission or direct
electrical communication via a wiring.
[0026] In order to ensure proper securement of the child seat to
the vehicle seat via the adjustable tethers a minimum amount of
tension must be present in the adjustable tethers when the child
seat is secured to the vehicle. An exemplary range of acceptable
tension is approximately 17-35 Newtons or approximately 3.8-8.0
pounds. Of course, it is understood that the aforementioned ranges
are provided as non-limiting examples and these ranges may vary to
be greater or less than the aforementioned ranges. In order to
monitor this amount of tension a tension sensor 42 is positioned to
detect the tension and provide a signal indicative of tension to
the microprocessor. In accordance with an exemplary embodiment
multiple sensors may be positioned in each of the tethers to
provide signals to the electronic control unit. Non-limiting
locations of the tension sensor are shown in FIGS. 1-3.
[0027] By measuring the tension in the tether it is now possible to
detect improper installation of the child seat due to the tethers
being twisted or misrouted; not being pulled taut once the clip(s)
engage the universal anchors or the clip(s) may be attached to the
incorrect anchor(s). By using a means to measure the tension on the
adjustable tether, the vehicle driver can be alerted that there is
a problem with the child seat installation.
[0028] In accordance with an exemplary embodiment the monitoring
device(s) or sensors are positioned at or about the attachment
point of the adjustable tether to the child seat wherein the amount
of tension on the tether(s) can be monitored. Alternatively, the
tension may be monitored by placing the tension monitoring
device(s) directly on or in-line with the tether(s) wherein the
tether(s) tension may be monitored. In yet another alternative, the
tension sensor would be located at the attachment point of clip(s),
latching device(s), hook(s), rigid clamp, etc. to tether(s). In yet
another alternative, the tension sensor may be placed on rigid
anchor for example as in U.S. Pat. No. 10/664,128, filed Sep. 17,
2003, the contents of which are incorporated herein by reference
thereto. In yet another alternative embodiment, the tension sensor
may be embedded into the webbing of the adjustable tether.
[0029] Several technologies may be used to sense the adjustable
tether(s) and/or anchor(s) tension load which may affect the most
desirable location for the sensor, non-limiting examples include
the point of contact between the tether and the shell wherein
tension on the tether will move a magnet, depress a force sensor
alternatively the sensor may be located at the tether to clasping
portion interface wherein tension on the tether will move a magnet,
depress a force sensor etc. in other applications force, strain
sensors or Hall effect sensors and if applicable magnets may be
disposed in the tether to sense the tension. Referring now to FIG.
5 several sensor contemplated technologies are contemplated for use
as a tension sensor; non-limiting examples include but are not
limited to a spring-loaded Hall Effect sensor, a strain gage
monitor, and an electro-mechanical switch. Examples of one such
tension sensing assembly are found in U.S. Pat. No. 6,749,038 the
contents of which are incorporated herein by reference thereto.
[0030] One non-limiting example of such a sensing device is a
magnetic member disposed in the tether and a Hall effect sensor
(illustrated schematically as item 42 in FIG. 1) positioned to
sense the magnetic field of the magnet. Thus, when the magnet moves
away the field changes and this is sensed by the sensor that
provides an output signal. The Hall effect device will sense the
strength of the magnetic field of the approaching magnet, and
depending on the strength of the magnetic field, the Hall effect
device will generate an electric signal (voltage or current), which
can be used to determine the tension in the adjustable tether. For
example, and in a non-limiting embodiment, the Vcc of the Hall
effect sensor assembly is 5 volts +/-0.5 volts DC. The voltage with
no magnetic field present will be approximately 2.5v. As the magnet
is brought into the proximity of the sensor, the voltage will
increase to near Vcc or decrease to near ground, depending on the
polarity of the magnet. Accordingly, as the voltage increases or
decreases, so does the tension of the seat belt. Thus, the sensor
can be calibrated to detect acceptable tension ranges. Of course,
Vcc may have values greater than and less than 5 volts.
[0031] Programmable ASIC applications of Hall Effect sensors are
known in the art which process the resultant signal from the
varying magnetic field and output a corresponding analog voltage or
digital data value. One non-limiting example of such a sensor is
the HAL 18XX family of sensors from Micronas, which is described in
the cited document entitled: HAL 18XX, Low-Cost Programmable Linear
Hall-Effect Sensor, the contents of which are incorporated herein
by reference thereto.
[0032] Alternatively, the device can be configured such that the
magnet moves further away from the Hall effect device when the
movable member is moved and the reduction in the magnetic field
will be sensed by the Hall effect device. In either embodiment, the
signal is received by an algorithm of the electronic control
unit.
[0033] Although the use of a Hall effect device is described above
it is also contemplated that other types of sensing devices may be
used to sense movement and provide an output signal indicative
thereof. For example, such alternatives include but are not limited
to the following: magneto-resistor, magnetosensitive devices,
anisotropic magnetoresistors, optical devices and equivalents
thereof. Also, a magnetic flux deflector may be employed in lieu of
a Hall effect device.
[0034] In embodiments wherein Hall effect devices are used the
location of the magnets secured to the tether must be in close
proximity to the Hall effect device so that movement can be
detected.
[0035] In one non-limiting example, tension sensor 42 will comprise
a housing 41 wherein a first portion 43 is secured to the child
seat shell and a second portion 45 is movably anchored to the
housing by a spring 47 at one end and the other end is secured to
the harness tether wherein tension on the tether will cause
movement of the second portion with respect to the first portion,
wherein a magnet 49 is disposed on the second portion and a Hall
effect device 51 is positioned on the first portion to detect
movement of the magnet and provide a signal the electronic control
unit. In one embodiment the spring constant can be calibrated to
expand in accordance with acceptable tension ranges thus, upon
application of a tension force in the acceptable range the spring
will be overcome and the magnet will move away or closer to the
Hall effect sensor. Non-limiting exemplary locations for housing 41
include but are not limited to being positioned between tether 14
and the child seat shell and/or between universal anchor 20 and the
clasping device.
[0036] Another exemplary sensing device could be an actuator
manipulated by the tether or a sensor disposed directly on the
tether. Another contemplated sensor is a Standard A201 sensor
available from FlexiForce. Further description of this sensor may
be found in U.S. Pat. No. 6,272,956, the contents of which are
incorporated herein by reference thereto. Such a sensor could be
disposed in the location illustrated schematically as item 42 in
FIGS. 1-3. Another alternative location for the sensor for
detecting the harness tether would be at a point of contact between
the tether and shell. For example, a force sensor can be positioned
at the point of contact between the tether and shell other than the
point of securement of the tether to the child seat. In this
embodiment, the tethers are positioned to make contact with the
force sensor positioned at the appropriate position of the child
seat where the applied force can be compared to an acceptable level
of force, which will correspond to an acceptable tension in the
tether. Such acceptable levels of force will correspond to the
angular position of the tether with respect to the shell and the
point of contact. In addition, the tether may be coated with a
coating at the point of contact to prevent wearing of the tether
and allow for low frictional resistance between the tether and the
force sensor to allow for sliding while detecting applied force.
Additionally, the force readings from the force sensors may each be
used in an equation of the control algorithm in order to determine
the harness tether tension.
[0037] In any of the aforementioned embodiments the sensor is
configured to provide a signal to an electronic control unit
coupled to the sensor, which comprises logic, comparators etc.
and/or is adapted to provide additional signals upon receipt of a
signal indicating the tether has a tension within an acceptable
range.
[0038] In each instance, the sensing principle is the same, only
the sensing technology is changing. The sensor monitors the tension
load exerted by the adjustable tether webbing through the selected
path, and/or the tension force exerted by the adjustable anchor
(FIG. 1). The sensor(s) may be either analog or discrete. An analog
sensor will continuously monitor the normal force exerted by the
adjustable tether webbing or at the rigid anchor base. By
monitoring the sensor output, a flag condition may be set when the
tension load force correlating to an appropriate installation cinch
force is met. A discrete sensor will be calibrated to toggle the
output status when the appropriate tension load force condition is
met.
[0039] The system controller will then input the signal into
algorithm in order to determine if the received signal corresponds
to a predetermined condition (e.g., tension or force on tether
within an acceptable range), which would cause the controller to
provide the indication means to the vehicle occupant. The algorithm
may have a look up table of signals, which correspond to tensions
and movements of the adjustable tether, which are compared to the
signal received. The sensor communicates a signal electronically to
the electronic control unit. The electronic control unit interprets
the signal and processes it algorithmically to determine the tether
status.
[0040] In accordance with an alternative exemplary embodiment the
sensor signal may then be processed in the electronic control unit
with other signals from a child seat for example a chest harness
buckle switch sensor and/or a chest harness tension sensor of the
restraint belts of the child seat. Accordingly, the electronic
control unit can determine the status of all the sensors and make
an appropriate determination whether the child is secured properly
in the child seat or not. The electronic control unit then can
provide an output to the driver such as "Insufficient adjustable
Tension", "adjustable Installation OK", or "adjustable Sensor
Faulted" as a result of performing internal electronic control unit
and sensor diagnostics, such text read outs may be viewable on a
liquid crystal display 48 of the display 44.
[0041] Each status indication can also be displayed as a series of
LED/lights that are visible to the driver, or through a speech
system, communicated by the electronic control unit, or
alternatively communicated to the vehicle for display in the
instrument panel as part of a display to the driver. In accordance
with an exemplary embodiment a standalone sensing system with an
internal power supply, such as a battery or kinetic device that
derives its power from the motion of the vehicle is provided
wherein the display is integral with the child seat. Alternatively,
the system could plug into the 12V DC power of the vehicle.
[0042] Referring now to FIG. 6, a flow chart for portions of a
control algorithm for determining the tension of at least one
tether of a child seat is shown. At step 60, the electronic control
unit initiates an evaluation of an adjustable tether tension. This
may be in response to manipulation of an activation button 62 on
the display of or coupled to the electronic control unit. At step
64, the electronic control unit receives an output signal from the
tension sensor. At decision node 68, the electronic control unit
compares the output signal to a value indicative of the
predetermined tension limit for the adjustable tether associated
with the tension sensor. In one exemplary embodiment, the output
signal of the tension sensor is a voltage proportional to the
tension of the tether and is compared to a voltage value
corresponding to a signal that would be produced for an acceptable
tension in the adjustable tether. Alternatively, a digital or
binary output may be received.
[0043] In an exemplary embodiment, the electronic control unit is
electrically coupled to the display that comprises the plurality of
lights or LEDs 46, such as green lights, that confirm acceptable
tension values in the adjustable tethers, and a plurality of lights
or LEDs 70, such as red lights, that are illuminated in response to
a signal indicating a tension outside of the predetermined range to
provide a warning of an improperly installed child seat. In an
non-limiting example the display will include indicia 72
identifying the adjustable tether wherein a green LED and a red LED
are positioned adjacent to each other to provide an indication of
whether the adjustable tether is installed properly by having a
predetermined amount of tension.
[0044] Accordingly, and if the signal(s) is/are in the acceptable
range, the electronic control unit outputs an electrical signal to
illuminate the green LED at step 74. Alternatively, and if the
signal is not within the acceptable range the electronic control
unit outputs an electrical signal to illuminate the red LED at step
76, wherein the red LED is indicative of improper installation and
the green LED is indicative of a proper installation. Thereafter,
nodes 78 and 80 will query if a stop command should be issued,
which may correspond to an expiration of a time period or the
system being shut down manually.
[0045] Alternative methods for providing indication of the tension
in the adjustable tether include but are not limited to an audible
chimes, and buzzers for providing an indication of an improper
installation, or audible text or a visual display with indicia. A
non-limiting example of a visual display is a liquid crystal
display (LCD).
[0046] Accordingly, exemplary embodiments of the present invention
provide a child seat with an electronic control unit that
determines the tension of the adjustable tether and illuminates an
indicator light, which is located on the child seat in a location
that would be easily viewed by the operator and/or occupants of the
vehicle, wherein the indicator light provides a means for
determining whether the adjustable tether is properly installed.
For example, one such location of the indicator light is on the
face of the control unit display. In addition, the microcontroller
may also provide an audible tone or voice response, indicating
whether the appropriate tension exists in the tether. In addition
exemplary embodiments of the present invention are contemplated for
use with various forward facing child seats, various booster seats
as well as rear-facing infant seats including those with detectable
carriers.
[0047] In addition, and in accordance with alternative exemplary
embodiments the electronic control unit can also be configured to
provide indications of other conditions relating to the child seat
and/or its installation. In this embodiment, the child seat will
comprise an electronic control unit secured to the child seat, the
electronic control unit being operably coupled to the tension
sensor to receive the tension signal and the electronic control
unit is also operably coupled to a plurality of sensors 90 each
providing additional signals indicative of states of the child seat
to the electronic control unit and the electronic control unit is
capable of processing the additional signals to compare the
additional signals to acceptable values, wherein the electronic
control unit provides additional outputs indicating whether the
additional signals are at acceptable values and the additional
outputs are provided to additional LEDs disposed on the display. Of
course, other methods of display are also contemplated for use in
this embodiment.
[0048] Examples of such additional such parameters being monitored
by the additional sensors include but are not limited to:
monitoring infant seat harness latch state; monitoring infant seat
harness tension; perform infant seat weight classification;
monitoring infant seat-to-base interlock state; monitoring infant
seat angle and seat orientation; monitoring infant seat for
exposure to severe impact or vehicle crash; monitoring rear facing
infant seat base for contact with vehicle seatbelt; monitoring rear
facing infant seat base for tension of vehicle seatbelt or lower
tether; monitoring chest retainer clip for proper engagement;
monitoring chest retainer clip for proper vertical height on the
harness; monitoring shoulder harness slots for proper adjustment
wherein audible and/or visual indications or warnings are provided
to alert an individual if there is non-compliance with any of the
monitored states.
[0049] In each instance, the sensors are electrically coupled to
the electronic control module wherein the electronic control module
provides an electrical signal indicative of the property being
sensed. The electronic control module will determine, using a
look-up table or analog circuit monitors and suitable algorithms, a
desired value for the sensed property, which desired value may be
based upon the tension of the tether as determined by the tension
sensor and if necessary, the control module provides an alert
signal. In accordance with an exemplary embodiment a simple analog
switch can be monitored with a simple comparator op-amp circuit, or
logic gate wherein a signal may be generated for illuminating the
display or providing another form of output (e.g., audible chime or
visual text message). For the display shown herein and in
accordance with an exemplary embodiment, the alert signal
illuminates a green light when the sensed property is within a
desired range, and a red light is illuminated when the sensed
property is not within the desired range.
[0050] While the invention has been described with reference to an
exemplary embodiment, it will be understood by those skilled in the
art that various changes may be made and equivalents may be
substituted for elements thereof without departing from the scope
of the invention. In addition, many modifications may be made to
adapt a particular situation or material to the teachings of the
invention without departing from the essential scope thereof.
Therefore, it is intended that the invention not be limited to the
particular embodiment disclosed as the best mode contemplated for
carrying out this invention, but that the invention will include
all embodiments falling within the scope of the appended
claims.
* * * * *