Force sensing seat belt sensor assembly

Patent metadata

Field	Value
Publication number	US-12228467-B2
Application number	US-202117490647-A
Country	US
Kind code	B2
Filing date	Sep 30, 2021
Priority date	Sep 30, 2020
Publication date	Feb 18, 2025
Grant date	Feb 18, 2025

Abstract

A seat belt sensor assembly comprises a force sensor coupled to a seat belt webbing. The seat belt sensor assembly utilizes force readings from the force sensor indicating a force level above or below a predetermined threshold to determine if an action needs to be taken to control a vehicle system. Such vehicle systems could include, but are not limited to, an autonomous driving control system, an occupant health system, and a motorized seat belt retractor system. Controlling the vehicle systems could include, but is not limited to, sending audio, visual, and/or haptic warnings to vehicle occupants, including, in one embodiment, that the occupant's respiration rate is indicative of a dangerous health condition. The seat belt sensor assembly may be used in combination with a camera-based occupant monitoring system. In one embodiment, the occupant monitoring system can be used to selectively activate/deactivate discrete activation zones of the force sensor.

First claim

The invention claimed is:

1. A seat belt sensor assembly comprising:
a seat belt webbing;
a human machine interface on the seat belt webbing comprising a plurality of force sensors coupled to the seat belt webbing, wherein the force sensors comprise discrete activation zones having a perimeter defined by respective electrodes that capture force levels applied to the discrete activation zones and transmit the force levels as capacitive measurements to an electronic control unit, wherein the capacitive measurements comprise a direct relationship between the force levels and a sensed capacitance at respective discrete activation zones;
wherein the electronic control unit comprises a processor communicatively coupled with a memory, the memory storing computer-readable instructions that implement software with the processor; and
a map of force sensor locations on the seat belt webbing stored in the memory,
wherein the processor of the electronic control unit executes the software to:
receive from the discrete activation zones the capacitive measurements from the force sensors;
calculate capacitive response tracking data for each of the discrete activation zones according to the map of force sensor locations;
identify user commands from the capacitive response tracking data; and
control a vehicle system with the user commands.

2. The seat belt sensor assembly of claim 1 , wherein the vehicle system comprises any of the following systems: an infotainment system, a cruise control system, an autonomous driving control system, an occupant health system, and a motorized seat belt retractor system.

3. The seat belt sensor assembly of claim 1 , wherein the vehicle system comprises an occupant health system and controlling the occupant health system comprises:
receiving a series of capacitive measurements from the force sensors over a period of time;
determining an occupant respiration condition based on changes in the series of capacitive measurements over the period of time; and
sending an alert to an occupant if the occupant respiration condition indicates an emergency situation.

4. The seat belt sensor assembly of claim 3 , wherein controlling the occupant health system further comprises:
sending a control message to an autonomous driving control system, the control message causing the autonomous driving control system to safely bring the vehicle to a stop.

5. The seat belt sensor assembly of claim 3 , wherein sending an alert to the occupant comprises any of the following: sending a visual warning to an infotainment system display, sending an audio warning to a vehicle sound system, and sending a haptic warning to a haptic feedback system.

6. The seat belt sensor assembly of claim 1 , further comprising a haptic feedback actuator coupled to the seat belt sensor assembly, wherein the software further causes the processor to send a haptic feedback signal to the haptic feedback actuator, causing the haptic actuator to provide a haptic response to the occupant.

7. The seat belt sensor assembly of claim 6 , wherein the haptic response to the occupant comprises a tactile or audio component.

8. The seat belt sensor assembly of claim 1 , wherein the force sensor comprises a stretchable and flexible sensor array with discrete activation zones.

9. The seat belt sensor assembly of claim 1 , wherein at least one of the force sensors is coupled to an occupant side of the seat belt webbing.

10. The seat belt sensor assembly of claim 1 , wherein at least one of the force sensors is laminated to an occupant side of the seat belt webbing.

11. The seat belt sensor assembly of claim 1 , wherein at least one of the force sensors is laminated between layers of the seat belt webbing.

12. The seat belt sensor assembly of claim 1 , wherein at least one of the force sensors is positioned in a seat belt webbing pocket.

13. The seat belt sensor assembly of claim 1 , wherein at least one of the force sensors is comprised of at least two force sensors connected in a single circuit.

14. The seat belt sensor assembly of claim 1 , wherein the seat belt webbing comprises a chest portion and a lap portion.

15. The seat belt sensor assembly of claim 14 , wherein a first force sensor is coupled to an occupant side of the seat belt webbing chest portion and a second force sensor is coupled to an occupant side of the seat belt webbing lap portion.

16. The seat belt sensor assembly of claim 1 , wherein the vehicle system comprises a motorized seat belt retractor system and controlling the motorized seat belt retractor system comprises:
receiving a series of capacitive measurements from at least one of the force sensors over a period of time;
determining a seat belt slack condition based on changes in the series of capacitive measurements over the period of time; and
sending a control message to the motorized seat belt retractor system, wherein the control message causes a motor to retract the seat belt webbing until a predetermined threshold force level is reached.

17. The seat belt sensor assembly of claim 1 , wherein the force levels applied to the force sensors comprise a touch by any of the following manual manipulations: a discrete press and release, a pinch, a pinch and slide, and a gesture.

18. A seat belt sensor system in a vehicle, comprising:
a seat belt webbing inside the vehicle;
an occupant monitoring system, wherein the occupant monitoring system comprises a camera in the vehicle with a field of view incorporating portions of the seat belt webbing;
a plurality of force sensors coupled to the seat belt webbing and defining discrete activation zones corresponding to respective electrodes on the seat belt webbing, wherein the force sensors capture a force level applied onto both sides of the seat belt webbing to respective discrete activation zones and wherein the respective electrodes transmit the force levels as capacitive measurements to an electronic control unit,
wherein the electronic control unit comprises a processor communicatively coupled with a memory, the memory storing computer-readable instructions and a map of the discrete activation zones on the seat belt webbing, wherein the processor executes the computer-readable instructions stored on the memory, the computer-readable instructions causing the processor to:
receive a series of images from the camera;
analyze the series of images to determine a force sensor condition;
selectively activate/deactivate the discrete activation zones based on the force sensor condition;
receive the capacitive measurements from selectively activated zones;
calculate capacitive response tracking data according to the map of the discrete activation zones;
identify user commands from the capacitive response tracking data; and
control a vehicle system with the user commands.

19. A seat belt sensor assembly comprising:
a seat belt webbing;
a human machine interface on the seat belt webbing comprising a plurality of force sensors coupled to the seat belt webbing, wherein the force sensors capture force levels applied to a surface and a different side of the force sensors and transmit the force levels as capacitive measurements to an electronic control unit,
wherein the electronic control unit comprises a processor communicatively coupled with a memory, the memory storing computer-readable instructions that implement software with the processor; and
a map of force sensor locations on the seat belt webbing stored in the memory,
wherein the processor of the electronic control unit executes the softw

Assignees

• Joyson Safety Systems Acquisition Llc

Inventors

• Cech Len
• Scholz Lukas
• Goudeau Darren
• Ramaglia Joshua

Classifications

• B60W2420/403

  Image sensing, e.g. optical camera · CPC title

• G01L1/146

  for measuring force distributions, e.g. using force arrays (G01L1/148 takes precedence) · CPC title

• B60R2022/4841

  for sensing belt tension · CPC title

• B60R2022/4666

  characterised by electric actuators · CPC title

• B60R22/48

  Control systems, alarms, or interlock systems, for the correct application of the belt or harness · CPC title