Driver monitoring camera
A driver monitoring camera comprises an optical sensor configured to take an image of a driver of a vehicle, an inclination sensor configured to determine an inclination of the driver monitoring camera with respect to a vehicle coordinate system and a processor configured to determine a pose of the driver in a driver monitoring camera coordinate system from the image and configured to transform the pose of the driver in the driver monitoring camera coordinate system to a pose of the driver in the vehicle coordinate system using the determined inclination.
1 . A driver monitoring camera mounted directly on a steering column of a vehicle, said driver monitoring camera comprising:
an optical sensor mounted on a camera printed circuit board and surrounded by a lens stack, said optical sensor being configured to obtain a sequence of images of a driver of the vehicle;
an inclination sensor mounted on a processor printed circuit board, said inclination sensor being configured to determine an inclination value of the driver monitoring camera with respect to a vehicle coordinate system; and
a processor mounted on the processor printed circuit board, said processor being in operative communication with the optical sensor and the inclination sensor via first and second connectors which interconnect the camera printed circuit board and the processor printed circuit board;
wherein the inclination sensor is further configured to monitor the inclination value of the driver monitoring camera with respect to the vehicle coordinate system and repeatedly indicate the inclination value of the driver monitoring camera with respect to the vehicle coordinate system to the processor via a signal which is filtered to eliminate or reduce an influence of jitter on the signal;
wherein the processor is further configured to determine a pose of the driver in a driver monitoring camera coordinate system from each image of the sequence of images and is further configured to transform the pose of the driver in the driver monitoring camera coordinate system to a pose of the driver in the vehicle coordinate system via a first inclination value indicated by the inclination sensor until the inclination sensor indicates a second inclination value which is different from the first inclination value by more than a predetermined threshold and to subsequently transform the pose of the driver in the driver monitoring camera coordinate system to the pose of the driver in the vehicle coordinate system via the second inclination value; and
wherein the processor is further configured to perform a control action depending on a determined pose of the driver of the vehicle; and
wherein the driver monitoring camera determines the pose of the driver in the vehicle coordinate system when vehicle interior landmarks are unavailable.
2 . The driver monitoring camera claim 1 , wherein the processor is further configured to determine a transformation matrix from the determined inclination value and transform the pose of the driver in the driver monitoring camera coordinate system to the pose of the driver in the vehicle coordinate system via the transformation matrix.
3 . The driver monitoring camera of claim 2 , wherein the inclination sensor is further configured to trigger an update of the transformation matrix by signaling a changed inclination value of the driver monitoring camera with respect to the vehicle coordinate system.
4 . The driver monitoring camera of claim 1 , wherein the processor is further configured to determine a transformation matrix from the determined inclination value and transform the pose of the driver in the driver monitoring camera coordinate system to the pose of the driver in the vehicle coordinate system via the transformation matrix; and wherein the processor is further configured to update a current transformation matrix when a change of value from the first inclination value based on which the processor has determined the current transformation matrix to the second inclination value determined by the inclination sensor is above a predetermined threshold.
5 . The driver monitoring camera of claim 1 , further comprising:
a housing holding the optical sensor and the inclination sensor.
6 . The driver monitoring camera of claim 5 , wherein the housing further holds the processor.
7 . A vehicle comprising:
a driver monitoring camera mounted directly on a steering column of the vehicle, the driver monitoring camera including:
an optical sensor mounted on a camera printed circuit board and surrounded by a lens stack, said optical sensor being configured to obtain a sequence of images of a driver of the vehicle;
an inclination sensor mounted on a processor printed circuit board, said inclination sensor being configured to determine an inclination value of the driver monitoring camera with respect to a vehicle coordinate system; and
a processor mounted on the processor printed circuit board, said processor being in operative communication with the optical sensor and the inclination sensor via first and second connectors which interconnect the camera printed circuit board and the processor printed circuit board;
wherein the inclination sensor is further configured to monitor the inclination value of the driver monitoring camera with respect to the vehicle coordinate system and repeatedly indicate the inclination value of the driver monitoring camera with respect to the vehicle coordinate system to the processor via a signal which is filtered to eliminate or reduce an influence of jitter on the signal;
wherein the processor is further configured to determine a pose of the driver in a driver monitoring camera coordinate system from each image of the sequence of images and is further configured to transform the pose of the driver in the driver monitoring camera coordinate system to a pose of the driver in the vehicle coordinate system via a first inclination value indicated by the inclination sensor until the inclination sensor indicates a second inclination value which is different from the first inclination value by more than a predetermined threshold and to subsequently transform the pose of the driver in the driver monitoring camera coordinate system to a pose of the driver in the vehicle coordinate system via the second inclination value;
wherein the processor is further configured to perform a control action depending on a determined pose of the driver in the vehicle coordinate system; and
wherein the driver monitoring camera determines the pose of the driver in the vehicle coordinate system when vehicle interior landmarks are unavailable.
8 . The vehicle of claim 7 , wherein the vehicle is a convertible.
9 . The vehicle of claim 7 , wherein the processor is further configured to determine a transformation matrix from the determined inclination value and transform the pose of the driver in the driver monitoring camera coordinate system to the pose of the driver in the vehicle coordinate system via the transformation matrix.
10 . The vehicle of claim 9 , wherein the inclination sensor is further configured to trigger an update of the rotation matrix by signaling a changed inclination value of the driver monitoring camera with respect to the vehicle coordinate system.
11 . The vehicle of claim 7 , wherein the processor is further configured to determine a transformation matrix from the determined inclination value and transform the pose of the driver in the driver monitoring camera coordinate system to the pose of the driver in the vehicle coordinate system via the transformation matrix; and wherein the processor is further configured to update a current transformation matrix when a change of inclination from the first inclination based on which the processor has determined the current transformation matrix to the second inclination determined by the inclination sensor is above a predetermined threshold.
12 . The vehicle of claim 7 , further comprising:
a housing holding the optical sensor and the inclination sensor.
13 . The vehicle of claim 12 , wherein the housing further holds the processor.