Detection of seatbelt position in a vehicle

1. A method of detecting seatbelt position in a vehicle having a seatbelt assembly and an image sensor, the method comprising:

determining a latch status of the seatbelt assembly as being latched or unlatched;

wherein the seatbelt assembly includes a belt webbing with a predefined webbing pattern;

if the latch status is latched, taking an image of at least a portion of the belt webbing with the image sensor;

determining if the belt webbing is in a preferred position based at least partially on the image, including searching the image for the predefined webbing pattern; and

wherein said searching the image for the predefined webbing pattern includes:

detecting at least one human face within the image;

placing a face boundary around the at least one human face within the image; and

searching a predefined search area around the face boundary for the predefined webbing pattern.

2. The method of claim 1 , wherein the belt webbing defines a first and a second edge and a plurality of infra-red reflectors positioned adjacent to the first and second edges.

3. The method of claim 1 , wherein the vehicle includes a display and further comprising:

if the belt webbing is not in the preferred position, displaying a first message on the display.

4. The method of claim 1 , wherein the vehicle includes a transmission shifter and further comprising:

if the belt webbing is not in the preferred position, disabling the transmission shifter to prevent shifting.

5. The method of claim 1 , wherein the seatbelt assembly includes a latch plate operatively connected to the belt webbing and said determining a latch status of the seatbelt assembly as being latched or unlatched includes:

connecting a magnetic element to the latch plate;

detecting the position of the latch plate with a position sensor; and

wherein the position sensor includes one or more hall sensors configured to sense the position of the latch plate by detecting a location of the magnetic element.

6. The method of claim 1 , wherein said determining if the belt webbing is in a preferred position further includes:

measuring an observed length of the belt webbing in the image; and

determining that the belt webbing is in the preferred position if the observed length is above a predefined minimum length.

7. The method of claim 1 , wherein the vehicle includes a vehicle seat operatively connected to the seatbelt assembly and said searching a predefined search area around the face boundary for the predefined webbing pattern includes:

determining whether a load applied to the vehicle seat is within one of a plurality of predetermined seat-load ranges;

employing a first search area as the predefined search area if the load applied to the vehicle seat is within a first of the plurality of predetermined seat-load ranges;

employing a second search area as the predefined search area if the load applied to the vehicle seat is within a second of the plurality of predetermined seat-load ranges; and

employing a third search area as the predefined search area if the load applied to the vehicle seat is within a third of the plurality of predetermined seat-load ranges.

8. A vehicle comprising:

a seatbelt assembly including a belt webbing, wherein the belt webbing has a predefined webbing pattern;

an image sensor configured to take an image of at least a portion of the belt webbing; and

a controller operatively connected to the image sensor and having a processor and tangible, non-transitory memory on which is recorded instructions for executing a method for detecting position of the belt webbing;

wherein execution of the instructions by the processor causes the controller to:

determine a latch status of the seatbelt assembly as being latched or unlatched;

if the latch status is latched, take an image of at least a portion of the belt webbing with the image sensor;

determine if the belt webbing is in a preferred position based at least partially on said image, including searching the image for the predefined webbing pattern; and

wherein said searching the image for the predefined webbing pattern includes:

detecting at least one human face within the image;

placing a face boundary around the at least one human face within the image; and

searching a predefined search area around the face boundary for the predefined webbing pattern.

9. The vehicle of claim 8 , wherein the belt webbing includes a plurality of infra-red reflectors.

10. The vehicle of claim 8 , wherein the belt webbing defines a first and a second edge and a plurality of infra-red reflectors positioned adjacent to the first and second edges.

11. The vehicle of claim 8 , wherein the vehicle includes a display and wherein the controller is configured to, if the belt webbing is not in the preferred position, display a first message on the display.

12. The vehicle of claim 8 , wherein the vehicle includes a transmission shifter and wherein the controller is configured to, if the belt webbing is not in the preferred position, disable the transmission shifter to prevent shifting.

13. The vehicle of claim 8 , wherein the seatbelt assembly includes a latch plate operatively connected to the belt webbing and wherein said determining a latch status of the seatbelt assembly as being latched or unlatched includes:

connecting a magnetic element to the latch plate;

detecting the position of the latch plate with a position sensor; and

wherein the position sensor includes one or more hall sensors configured to sense the position of the latch plate by detecting a location of the magnetic element.

14. The vehicle of claim 8 , wherein said determining if the belt webbing is in a preferred position includes:

measuring an observed length of the belt webbing in the image; and

determining that the belt webbing is in the preferred position if the observed length is above a predefined minimum length.

15. The vehicle of claim 8 , wherein the vehicle includes a vehicle seat operatively connected to the seatbelt assembly and said searching a predefined search area around the face boundary for the predefined webbing pattern includes:

determining whether a load applied to the vehicle seat is within one of a plurality of predetermined seat-load ranges;

employing a first search area as the predefined search area if the load applied to the vehicle seat is within a first of the plurality of predetermined seat-load ranges;

employing a second search area as the predefined search area if the load applied to the vehicle seat is within a second of the plurality of predetermined seat-load ranges; and

employing a third search area as the predefined search area if the load applied to the vehicle seat is within a third of the plurality of predetermined seat-load ranges.

16. A method of detecting seatbelt position in a vehicle having a seatbelt assembly, a transmission shifter and an image sensor, the method comprising:

determining a latch status of the seatbelt assembly as being latched or unlatched;

wherein the seatbelt assembly includes a belt webbing with a predefined webbing pattern;

if the latch status is latched, taking an image of at least a portion of the belt webbing with the image sensor;

determining if the belt webbing is in a preferred position based at least partially on the image, including:

searching the image for the predefined webbing pattern;

measuring an observed length of the belt webbing in the image; and

determining that the belt webbing is in the preferred position if the observed length is above a predefined minimum length;

if the belt webbing is not in the preferred position, disabling the transmission shifter to prevent shifting; and

wherein said searching the image for the predefined webbing pattern includes:

detecting at least one human face within the image;

placing a face boundary around the at least one human face within the image; and

searching a predefined search area around the face boundary for the predefined webbing pattern.