Systems and methods for estimating levelness of a trailer and providing levelling guidance

A system for measuring how level a trailer is, the system comprising:

• a vehicle comprising a vehicle levelness estimator;
• a trailer connectable to the vehicle;
• a rear facing camera mounted on the vehicle;
• at least one processor in operable communication with the rear facing camera, wherein the at least one processor is configured to execute program instructions, wherein the program instructions are configured to cause the at least one processor to:
• capture an image of the trailer using the rear facing camera, the image encompassing a front face of the trailer;
• receive a vehicle levelness parameter from the vehicle levelness estimator of the vehicle, the vehicle levelness parameter indicating how level the vehicle is, based on a digital elevation map and a current location of the vehicle;
• determine a rotation angle of the trailer relative to the vehicle based on the image and a comparison of the image with a stored reference image that was captured at a known roll angle of the trailer;
• determine a vision-based estimated trailer levelness parameter based on the rotation angle and the vehicle levelness parameter, the vision-based estimated trailer levelness parameter indicating how level the trailer is using the image from the rear facing camera of the vehicle, the vehicle level parameter from the digital elevation map and the current location of the vehicle, and the stored reference image;
• receive a sensor-based trailer levelness parameter based on a levelness measurement from a trailer levelness estimator disposed on the trailer, wherein the levelness estimator comprises an inertial measurement unit (IMU) that is disposed on a surface of the trailer;
• determine a fused trailer levelness parameter based on a fusion of both (A) the vision-based estimated trailer levelness parameter with (B) the sensor-based trailer levelness parameter, utilizing different estimates at different respective times of both the vision-based estimated trailer levelness parameter and the sensor-based trailer levelness parameter, wherein the fusion of the estimated trailer levelness parameter with the sensor based trailer levelness parameter is weighted based on an inverse of variance that is tracked over time;
• output the estimated trailer levelness parameter;
• and
• automatically adjusting a height under one or more wheels of the trailer, in accordance with instructions provided by the at least one processor.