Device and method for detecting an object or a person on a seat of vehicle

• US 7,209,033 B2
• Filed: 09/01/2004
• Issued: 04/24/2007
• Est. Priority Date: 09/09/2003
• Status: Expired due to Fees

• Current Assignee: Continental Automotive GmbH (Continental AG)
• Original Assignee: Siemens AG
• Inventors: Hofbeck, Klaus, Pfau, Lorenz, Rosel, Birgit
• Primary Examiner(s): Wu; Daniel
• Assistant Examiner(s): HUNNINGS, TRAVIS R
• Application Number:
  US10/931,402
• Publication Number:
  US 20050062595A1
• Time in Patent Office: 965 Days
• Field of Search: 340/457, 340/457.1, 340/573.1, 340/426, 340/439, 180/271, 180/286, 180/287, 180/289, 280/735
• US Class Current: 340/457.1
• CPC Class Codes: B60N 2/002 Seats provided with an occupancy detection means mounted therein or thereon detection means responsive to presence or absence of children B60N2/266
• CPC Class Codes: B60N 2/0027 for detecting the position of the occupant or of occupant's body part
• CPC Class Codes: B60N 2/003 characterised by the sensor mounting location in or on the seat
• CPC Class Codes: B60N 2/0035 characterised by the sensor data transmission, e.g. wired connections or wireless transmitters therefor; characterised by the sensor data processing, e.g. seat sensor signal amplification or electric circuits for providing seat sensor information
• CPC Class Codes: B60N 2/272 Buckle lock sensors for child seat safety belts
• CPC Class Codes: B60N 2210/22 Optical; Photoelectric; Lidar [Light Detection and Ranging]
• CPC Class Codes: B60R 2021/0067 Buses
• CPC Class Codes: B60R 2021/0093 Aircraft
• CPC Class Codes: B60R 2022/4808 Sensing means arrangements therefor
• CPC Class Codes: B60R 22/48 Control systems, alarms, or interlock systems, for the correct application of the belt or harness

Abstract

The device has a transceiver which transmits high-frequency signals, which are reflected back by reflectors in the seats. Occupied seats are detected on the basis of signal propagation delays and/or reflector detections and/or receiving intensities. In addition, it is possible to detect with the aid of a belt sensor whether or not a safety belt is fastened.

Claims

1. A device for detecting an object on a seat of a vehicle, the device comprising:

at least one high-frequency transmitter disposed in vicinity of the seat and configured to transmit high-frequency signals;

one or a plurality of reflectors for reflecting high-frequency signals disposed in or on the seat to cause the high-frequency signals to traverse an object on the seat at least partially attenuated;

a high-frequency receiver disposed to receive the high-frequency signals after reflection at one of said reflectors;

an evaluating unit connected to said high-frequency transmitter and to said high-frequency receiver and configured to determine information concerning an occupancy of the seat from at least two of the following;

a signal propagation delay between transmitting and receiving, information contained in the high-frequency signals, and a received signal strength;

a safety belt disposed to secure the object on the seat; and

a belt sensor connected to said evaluating unit, said belt sensor enabling a detection whether or not said safety belt has been fastened.

2. The device according to claim 1, wherein said belt sensor is a seat belt buckle switch in a belt buckle of said safety belt, and said buckle switch is activated by engaging a belt clasp in the belt buckle.

3. The device according to claim 1, wherein said belt sensor is a belt reflector disposed on or in said safety belt.

4. The device according to claim 1, wherein said high-frequency transmitter and said high-frequency receiver are implemented in a common unit forming a transceiver.

5. The device according to claim 1, which further comprises a display device connected to said evaluating unit, for displaying whether or which seats are occupied and/or whether or not the safety belts are being worn.

6. The device according to claim 1, wherein said high-frequency transmitter and said high-frequency receiver and said evaluating unit connected thereto form a part of an added-feature control system in a motor vehicle, wherein at least one vehicle-specific function is controlled depending on at least one of a determined presence of an object on a seat and a fastened safety belt.

7. The device according to claim 1, wherein said reflectors include a first reflector disposed on a first seat and a second reflector disposed on a second seat, said reflectors are configured to reflect the high-frequency signals with information enabling said evaluating unit to determine whether the reflected signal originates from said first reflector or from said second reflector.

8. The device according to claim 7, wherein said first reflector is disposed in or on a first seat and said second reflector is disposed in or on a second seat of the vehicle.

9. A method of detecting an object on a seat of a vehicle, the method which comprises:

transmitting high-frequency signals with a high-frequency transmitter and receiving the signals with a high-frequency receiver and causing the high-frequency signals to at least partially traverse the object located on the seat and to thereby attenuate the signal;

determining an occupancy of the seat from at least two items of information selected from a signal propagation delay between transmitting and receiving, an information contained in the high-frequency signals, and a signal strength of a received signal; and

detecting from a belt sensor signal whether or not the seat belt is fastened if the seat has been determined to be occupied.

10. The method according to claim 9, which comprises transmitting the signals directly from the transmitter to the receiver substantially without reflecting the signals.

11. The method according to claim 9, which comprises reflecting the signals with a reflector between the high-frequency transmitter and the high-frequency receiver and imparting on the signals a reflector-specific characteristic identifier enabling a control unit connected to the receiver to determine the reflector from which the signal was reflected.

12. The method according to claim 9, which comprises reflecting the signals with a plurality of reflectors between the high-frequency transmitter and the high-frequency receiver.

13. A method of detecting an object on a seat of a vehicle, the method which comprises:

transmitting high-frequency signals with a high-frequency transmitter broadband in modulated form;

reflecting the signals with each of a plurality of reflectors or a group of reflectors between the high-frequency transmitter and the high-frequency receiver with a predefined frequency;

receiving the signals with a high-frequency receiver and determining an occupancy of the seat from at least one item of information consisting of a signal propagation delay between transmitting and receiving, an information contained in the high-frequency signals, and a signal strength of a received signal; and

if the seat has been determined to be occupied, detecting from a belt sensor signal whether or not the seat belt is fastened.

14. A method of detecting an object on a seat of a vehicle, the method which comprises:

transmitting signals with a plurality of high-frequency transmitters, and transmitting the signals in different transmission channels at different modulation frequencies or temporally graduated;

receiving the signals with a high-frequency receiver and determining an occupancy of the seat from at least one item of information consisting of a signal propagation delay between transmitting and receiving, an information contained in the high-frequency signals, and a signal strength of a received signal; and

if the seat has been determined to be occupied, detecting from a belt sensor signal whether or not the seat belt is fastened.

15. A method of detecting an object on a seat of a vehicle, the method which comprises:

transmitting high-frequency signals with a high-frequency transmitter, reflecting the signals with a plurality of reflectors between the high-frequency transmitter and a high-frequency receiver, and receiving the signals with the high-frequency receiver and causing the high-frequency signals to at least partially traverse the object located on the seat and to thereby attenuate the signal;

reflecting the signals in differing polarized forms with the reflectors, and receiving the high-frequency signals in differently polarized form with the high-frequency receivers.