Liftgate opening height control

1. Vehicle apparatus comprising:

a liftgate system with a vertically-opening liftgate and a power actuator responsive to a user opening command for opening the liftgate to a variable opening height;

an active sensor adapted to detect objects and respective distances to objects within a detection zone behind the vehicle apparatus;

a camera adapted to capture a search image with a field-of-view showing objects in the detection zone; and

a controller coupled to the liftgate system, active sensor, and camera, wherein in response to the user opening command the controller 1) performs facial recognition on the search image to detect image locations containing a face of each respective person visible in the search image, 2) identifies distances for each respective person according to coincidence with the detected objects, 3) determines a user height according to the respective image location and distance of at least one respective person visible in the search image, and 4) sets the variable opening height in response to the user height.

2. The apparatus of claim 1 wherein the controller 5) compares a plurality of user heights determined according to a plurality of respective image locations and distances of a plurality of respective persons visible in the search image, and wherein the controller sets the variable opening height using a tallest one of the user heights.

3. The apparatus of claim 1 wherein the camera is mounted on the liftgate, and wherein the search image is captured during opening of the liftgate when the liftgate is at a predetermined capture height.

4. The apparatus of claim 1 wherein the active sensor is comprised of an array of ultrasonic sensors.

5. The apparatus of claim 1 wherein whenever the controller fails to identify any person in the search image corresponding to the detected objects then the variable opening height is set to a default opening height.

6. The apparatus of claim 5 wherein the controller stores the set opening height as the default opening height whenever the controller sets the variable opening height in response to identifying a person in the search image.

7. The apparatus of claim 5 wherein the default opening height is manually configured by a user.

8. The apparatus of claim 1 wherein after the liftgate stops at the variable opening height the controller monitors for detected objects moving within a predetermined zone, and if a predetermined time period elapses with the predetermined zone being empty of any detected moving objects then the controller commanding an automatic closing of the liftgate.

9. A method of controlling a liftgate system on a vehicle, wherein the liftgate system has a vertically-opening liftgate and a power actuator responsive to a user opening command for opening the liftgate, wherein the vehicle has an active sensor adapted to detect objects and respective distances to objects within a detection zone behind the vehicle and a camera adapted to capture a search image with a field-of-view showing objects in the detection zone behind the vehicle, the method comprising the steps of:

receiving a user opening command;

initiating the power actuator to open the liftgate;

capturing the search image with the camera;

sensing the detected objects with the active sensor;

performing facial recognition on the search image to detect image locations containing a face of each respective person visible in the search image;

identifying distances for each respective person according to coincidence with the detected objects;

determining a user height according to the respective image location and distance of at least one respective person visible in the search image; and

setting a variable opening height in response to the user height so that the opening of the liftgate stops at the variable opening height.

10. The method of claim 9 further comprising the step of:

comparing a plurality of user heights determined according to a plurality of respective image locations and distances of a plurality of respective persons visible in the search image;

wherein the set variable opening height is selected as a tallest one of the user heights.

11. The method of claim 9 wherein the camera is mounted on the liftgate, and wherein the search image is captured during opening of the liftgate when the liftgate is at a predetermined capture height.

12. The method of claim 9 wherein the active sensor is comprised of an array of ultrasonic sensors.

13. The method of claim 9 further comprising the step of setting the variable opening height to a default opening height whenever the facial recognition step fails to identify any person in the search image corresponding to one of the detected objects.

14. The method of claim 13 further comprising the step of:

storing the set opening height corresponding to the determined user height whenever the controller sets the variable opening height in response to identifying a person in the search image.

15. The method of claim 13 wherein the default opening height is manually configured by a user.

16. The method of claim 9 further comprising the steps of:

monitoring for detected objects moving within a predetermined zone after the liftgate stops at the variable opening height; and

if a predetermined time period elapses with the predetermined zone being empty of any detected moving objects then commanding closing of the liftgate.

17. Vehicle apparatus comprising:

a liftgate system with a vertically-opening liftgate and a power actuator responsive to a user opening command for opening the liftgate to a variable opening height;

an active sensor adapted to detect objects and respective distances to objects within a detection zone;

a camera adapted to capture a search image with a field-of-view showing objects in the detection zone; and

a controller coupled to the liftgate system, active sensor, and camera, wherein in response to the user opening command the controller 1) performs facial recognition on the search image to detect image locations containing a face of each respective person visible in the search image, 2) identifies distances for each respective person according to coincidence with the detected objects, 3) determines a user height according to the respective image location and distance of at least one respective person visible in the search image, 4) compares a plurality of user heights determined according to a plurality of respective image locations and distances of a plurality of respective persons visible in the search image, and 5) sets the variable opening height in response to a tallest one of the user heights;

wherein the detection zone has a near region and a far region, and wherein as long as there is at least one respective person within the near region then the comparison of user heights considers only the respective persons determined to be within the near region.

18. A method of controlling a liftgate system on a vehicle, wherein the liftgate system has a vertically-opening liftgate and a power actuator responsive to a user opening command for opening the liftgate, wherein the vehicle has an active sensor adapted to detect objects and respective distances to objects within a detection zone and a camera adapted to capture a search image with a field-of-view showing objects in the detection zone, the method comprising the steps of:

receiving a user opening command;

initiating the power actuator to open the liftgate;

capturing the search image with the camera;

sensing the detected objects with the active sensor;

performing facial recognition on the search image to detect image locations containing a face of each respective person visible in the search image;

identifying distances for each respective person according to coincidence with the detected objects;

comparing a plurality of user heights determined according to a plurality of respective image locations and distances of a plurality of respective persons visible in the search image;

determining a user height according to the respective image location and distance of at least one respective person visible in the search image; and

setting a variable opening height in response to the user height so that the opening of the liftgate stops at the variable opening height, wherein the set variable opening height is selected as a tallest one of the user heights

wherein the detection zone has a near region and a far region, and wherein as long as there is at least one respective person within the near region then the comparison of user heights considers only the respective persons determined to be within the near region.