U.S. patent application number 09/085814 was filed with the patent office on 2001-05-24 for method and arrangement for seat occupancy recognition in a motor vehicle.
This patent application is currently assigned to Rudolph Mai. Invention is credited to MAI, RUDOLPH, SINNHUBER, RUPRECHT, ZANDER, ANDRE.
Application Number | 20010001522 09/085814 |
Document ID | / |
Family ID | 7830595 |
Filed Date | 2001-05-24 |
United States Patent
Application |
20010001522 |
Kind Code |
A1 |
MAI, RUDOLPH ; et
al. |
May 24, 2001 |
METHOD AND ARRANGEMENT FOR SEAT OCCUPANCY RECOGNITION IN A MOTOR
VEHICLE
Abstract
A method and arrangement for seat occupancy recognition in a
motor vehicle utilizes a seat occupancy sensor which is triggered
only for an interval of time and only in predetermined
situations.
Inventors: |
MAI, RUDOLPH; (WOLFSBURG,
DE) ; SINNHUBER, RUPRECHT; (GIFHORN, DE) ;
ZANDER, ANDRE; (HALBERSTADT, DE) |
Correspondence
Address: |
BAKER AND BOTTS
30 ROCKEFELLER PLAZA
NEW YORK
NY
10112
|
Assignee: |
Rudolph Mai
|
Family ID: |
7830595 |
Appl. No.: |
09/085814 |
Filed: |
May 27, 1998 |
Current U.S.
Class: |
280/735 ;
280/734 |
Current CPC
Class: |
B60N 2/002 20130101;
B60R 21/0154 20141001; B60R 21/01532 20141001; B60R 21/01534
20141001 |
Class at
Publication: |
280/735 ;
280/734 |
International
Class: |
B60R 021/32 |
Foreign Application Data
Date |
Code |
Application Number |
May 27, 1997 |
DE |
197 22 085.1 |
Claims
We claim:
1. A method for seat occupancy recognition in a motor vehicle
utilizing at least one seat occupancy sensor comprising the step
of: actuating the seat occupancy sensor only in a predetermined
situation and only for a limited time interval.
2. A method according to claim 1 comprising actuating the seat
occupancy sensor upon starting of a vehicle engine when all vehicle
doors are closed.
3. A method according to claim 1 comprising actuating the seat
occupancy sensor upon closing of a vehicle door when the engine is
running.
4. A method according to claim 1 comprising actuating the seat
occupancy sensor by a sensor that detects a collision of the
vehicle with an obstacle before deceleration of the vehicle due to
the collision affects the interior of the vehicle and
occupants.
5. A method according to claim 1 comprising actuating that the seat
occupancy sensor by a sensor that detects an impending collision
with an obstacle.
6. A method according to claim 1 comprising recognizing seat
occupancy in each of a plurality of predetermined situations
utilizing a sensor profile which is specific to each of the
predetermined situations.
7. A method according to claim 6 comprising initiating seat
occupancy recognition upon starting of the vehicle engine and/or
upon closing of the vehicle doors, and detecting the position of
the vehicle seat and/or the sitting position of a vehicle seat
occupant utilizing the seat occupancy sensor.
8. A method according to claim 1 comprising controlling a seat
heater with the seat occupancy sensor.
9. An arrangement for recognizing seat occupancy in a motor vehicle
comprising a seat occupancy sensor and at least one of: a sensor to
detect a collision or an impending collision with an obstacle; a
door condition sensor; and an engine condition sensor, for
controlling the operation of the seat occupancy sensor.
10. An arrangement according to claim 9 wherein the seat occupancy
sensor is connected to a seat heater.
11. An arrangement according to claim 9 further comprising a
counter responsive to at least one of: a collision or impending
collision sensor; a door condition sensor; and an engine condition
sensor, for activating the seat occupancy sensor for a limited time
interval.
Description
BACKGROUND OF THE INVENTION
[0001] This invention relates to methods and arrangements for seat
occupancy recognition in motor vehicles.
[0002] For many reasons, knowing whether a vehicle seat is occupied
and the nature of the occupancy is very important. If, for example,
a child seat is in an incorrect position on a vehicle seat,
triggering of an airbag may have serious consequences for a child
in the child seat. Knowledge of the location of a person on a
vehicle seat is of great interest since it is important to the
function of an airbag that a minimum distance should be assured
between the occupant and the airbag at the beginning of airbag
release so that there will be enough time for the airbag to expand
in a collision. Also, the airbag should be released only if the
vehicle seat really is occupied, since repair of the released
airbag is very expensive. Furthermore, comfort functions may be
adjusted according to seat occupancy, like an air-conditioning unit
or a fan which may be operated according to whether passenger seat
is occupied or not.
[0003] German Patent No. 38 02 159 discloses a seat occupancy
recognition arrangement for motor vehicles having adjustable seats
in which occupancy of a vehicle seat is determined by a comparator
which operates a switch, by displacement transducers detecting the
position of the seat relative to the vehicle and the parts of seat
relative to each other, and by a contact-free range finder
measuring a distance from a seat surface or a part of a seat
surface to a part of the vehicle on which a range finder is
mounted. The comparator calculates a distance from the surface of
the vehicle seat to the range finder sensor from position data of
the displacement transmitters, compares the distance with that
determined by the range finder and, if the readings coincide,
triggers the switch. The range finder is preferably in the form of
an ultrasonic or infrared sensor which transmits an ultrasonic or
infrared signal toward the vehicle seat and receives a signal
reflected from that direction by a surface of a person sitting on
the seat or, if the seat is unoccupied, from the back rest of the
seat, by which the seat occupancy condition may be inferred from
the transit time of the signal.
[0004] U.S. Pat. No. 5,330,226 discloses a seat occupancy
recognition arrangement in which an infrared sensor is mounted in
the roof above the seat. The infrared sensor has a plurality of
fields of vision by which the position of an occupant relative to
the airbag is determined so that the airbag, when released, can be
suitably triggered without injuring the occupant.
[0005] German Offenlungsschrift No. 41 10 702 discloses a seat
occupancy recognition arrangement for actuating a seat heater in
which a seat heating conductor mounted in the seat surface and
heatable by electric current forms the first electrode of a
capacitive seat occupancy sensor consisting of two electrodes.
[0006] A disadvantage of all prior art occupant detecting
arrangements is that the vehicle occupants are continuously exposed
to sources of radiation. Since the effects of long-term exposure to
electromagnetic radiation, or to ultrasonic waves, are much in
dispute, there is a danger that the well-being of the occupants may
be impaired, or even that they may be injured, by a continuous
exposure to radiation.
SUMMARY OF THE INVENTION
[0007] Accordingly, it is an object of the present invention to
provide a method and arrangement for seat occupancy recognition in
a motor vehicle which overcomes disadvantages of the prior art.
[0008] Another object of the invention is to provide a method and
arrangement for seat occupancy recognition in a motor vehicle in
which the occupants are subjected as little as possible to any kind
of radiation.
[0009] These and other objects of the invention are attained by
providing a method and arrangement for seat occupancy recognition
in a motor vehicle in which a recognition device is actuated only
in predefined situations and only for a certain interval of time.
Consequently, the exposure of the occupants to radiation produced
by the seat occupancy recognition device is reduced to an
acceptable level.
[0010] Since a change in seat occupancy always requires a person
getting in or a person getting out of a vehicle, most relevant
situations involving a change of seat occupancy can be detected by
a door condition sensor and/or an engine condition sensor. If the
motor vehicle is started, the sensor must first check to determine
which vehicle seats are occupied. For this purpose, various
permutations are possible. Thus, the driver may get in and proceed
to start the engine before all occupants are in the vehicle or the
driver may wait to start the engine until after all occupants are
seated. Since reliable seat occupancy recognition is possible only
after the last action, preferably there should be an alternative
scan by the detector in that condition.
[0011] In another preferred embodiment, a seat occupancy or
occupant position recognition occurs only if a sensor for detecting
an impending collision to trigger an airbag generates a signal, in
which case the configuration of the sensor is such that it will
detect a collision, or an impending collision, before any
deceleration of the vehicle due to the collision affects the
interior of the vehicle or its occupants.
[0012] According to one embodiment of the invention, the sensor for
detecting an impending collision is a "pre-crash sensor." A
pre-crash sensor consists of a plurality of individual sensors
covering a neighborhood around the vehicle. If an object, or an
obstacle, is detected in the neighborhood of the vehicle, the
sensor detects the current distance of the object from the vehicle,
and possibly the relative velocity between object and the vehicle,
in order to signal an impending collision with the object.
[0013] According to another embodiment, an engine- and/or
door-condition sensor detects whether a vehicle is occupied, and
only the precise position of the vehicle seat and the sitting
position of the occupant remain to be determined by a seat
occupancy recognition arrangement which is actuated by the sensor
for detecting a collision or impending collision.
BRIEF DESCRIPTION OF THE DRAWING
[0014] Further objects and advantages of the invention will be
apparent from a reading of the following description in conjunction
with the accompanying drawing which is a schematic block diagram
illustrating a representative embodiment of an arrangement for seat
occupancy recognition in a motor vehicle according to the
invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0015] In the typical embodiment of the invention shown in the
drawing, a seat occupancy recognition arrangement 1 comprises a
door-condition sensor 2 and an engine-condition sensor 3, and logic
level recognition devices 4 and 5 associated with each of the
sensors 2 and 3, respectively. The signal output from the sensor 2
or 3, together with the signal output of the logic level
recognition device 5 for 4 or the other sensor 3 or 2, as the case
may be, is supplied to the input of an AND gate 6 or 7,
respectively. The signal outputs of the AND gates 6 and 7 are
linked disjunctively by way of an OR gate 9 providing an output to
a counter 10. The counter 10 is connected to a seat occupancy
sensor 11 which, in turn, is operatively connected with an
associated vehicle seat 12 and a seat heater 13. The recognition
arrangement 1 further includes a pre-crash sensor 14 connectable
either to the counter 10 or directly to the seat occupancy sensor
11.
[0016] Thus, in one example, a motor vehicle operator enters his
vehicle and waits until his passengers are seated and the vehicle
door is closed. When the doors are closed, there is a logic level 1
at the output of the door condition sensor 2. When the operator
starts the engine, the logic condition at the output of the engine
condition sensor 3 changes from logic 0 to logic 1. This positive
logic level is detected by the logic level recognition device 5,
which then changes its output from logic level 0 to logic level 1.
Thus, both inputs of the AND gate 7 are at logic 1, and its output
also switches to logic level 1, and consequently, the output of the
OR gate 9 switches to logic level 1. The logic level 1 of the OR
gate 9 enables the counter 10. The counter 10 then starts counting
and runs up to a certain count which is either hard-wired or freely
programmable. As long as the counter 10 runs, the seat occupancy
sensor 11 is activated and detects whether the vehicle seat 12 is
occupied. If the seat occupancy sensor 11 detects an occupant, the
corresponding seat heater 13 is switched on. The seat occupancy
sensor 11 may, for example, be an infrared, ultrasonic or
capacitance sensor. When the counter 10 reaches its set count, it
generates a reset signal 15 for the logic level recognition devices
4 and 5 to disable the sensors.
[0017] If a hazardous situation arises during vehicle operation
that might call for release of the airbag, the pre-crash sensor 14
generates a signal that either enables the counter 10 or directly
activates the seat occupancy sensor 11. The latter then determines
the exact position of the occupant in order to control the airbag
in such a way that its release will not injure the occupant. The
seat heater 13 may be switched off either upon opening of the
corresponding door or when the engine is shut off, or else by a
negative result at the next seat occupancy recognition
interval.
[0018] Although the invention has been described herein with
reference to specific embodiments, many modifications and
variations therein will readily occur to those skilled in the art.
Accordingly, all such variations and modifications are included
within the intended scope of the invention.
* * * * *