Trailer backup assist system with hitch angle offset estimation
A system for estimating hitch angle offset is provided herein. A sensor system is configured to measure hitch angles between a vehicle and a trailer attached thereto. A controller is configured to calculate hitch angle offsets for a plurality of measured hitch angles, and extrapolate additional hitch angle offsets based on the calculated hitch angle offsets.
1. A system for estimating hitch angle offset comprising:
a sensor system configured to measure hitch angles between a vehicle and a trailer attached thereto; and
a controller configured to:
calculate hitch angle offsets for a plurality of measured hitch angles;
extrapolate additional hitch angle offsets based on the calculated hitch angle offsets; and
assist with guiding the vehicle to reverse the trailer on a backing path based on the extrapolated additional hitch angle offsets.
2. The system of claim 1 , wherein the sensor system comprises a camera of the vehicle that monitors a target on the trailer.
3. The system of claim 1 , wherein each of the hitch angle offsets are calculated when a corresponding measured hitch angle is substantially constant.
4. The system of claim 1 , wherein each of the hitch angle offsets are calculated as a function of a trailer length, a wheelbase length, a drawbar length, and a steering angle.
5. The system of claim 1 , wherein each of the hitch angle offsets are calculated when a yaw rate of the vehicle and the trailer are substantially equal and constant.
6. The system of claim 1 , wherein the controller performs a curve fit between the calculated hitch angle offsets to estimate the additional hitch angle offsets, the additional hitch angle offsets being related to measurable hitch angles for operating a trailer backup assist system.
7. The system of claim 6 , wherein the curve fit is one of a linear function and a higher order function.
8. A system for estimating hitch angle offset comprising:
a sensor system configured to measure hitch angles between a vehicle and a trailer attached thereto; and
a controller configured to:
calculate hitch angle offsets for a plurality of measured hitch angles when a yaw rate of the vehicle and the trailer are substantially equal and constant;
extrapolate additional hitch angle offsets based on the calculated hitch angle offsets; and
assist with guiding the vehicle to reverse the trailer on a backing path based on the extrapolated additional hitch angle offsets.
9. The system of claim 8 , wherein the sensor system comprises a camera of the vehicle that monitors a target on the trailer.
10. The system of claim 8 , wherein each of the hitch angle offsets are calculated when a corresponding measured hitch angle is substantially constant.
11. The system of claim 8 , wherein each of the hitch angle offsets are calculated as a function of a trailer length, a wheelbase length, a drawbar length, and a steering angle.
12. The system of claim 8 , wherein the controller performs a curve fit between the calculated hitch angle offsets to estimate the additional hitch angle offsets, the additional hitch angle offsets being related to measurable hitch angles for operating a trailer backup assist system.
13. The system of claim 12 , wherein the curve fit is one of a linear function and a higher order function.
14. A method for estimating hitch angle offset comprising the steps of:
measuring hitch angles between a vehicle and a trailer attached thereto;
calculating hitch angle offsets for the measured hitch angles;
extrapolating additional hitch angle offsets based on the calculated hitch angle offsets; and
assisting with guiding the vehicle to reverse the trailer on a backing path based on the extrapolated additional hitch angle offsets.
15. The method of claim 14 , wherein the hitch angles are measured by a camera of the vehicle that monitors a target on the trailer.
16. The method of claim 14 , wherein each of the hitch angle offsets are calculated when a corresponding measured hitch angle is substantially constant.
17. The method of claim 14 , wherein each of the hitch angle offsets are calculated as a function of a trailer length, a wheelbase length, a drawbar length, and a steering angle.
18. The method of claim 14 , wherein each of the hitch angle offsets are calculated when a yaw rate of the vehicle and the trailer are substantially equal and constant.
19. The method of claim 14 , wherein the step of extrapolating comprises performing a curve fit between the calculated hitch angle offsets to estimate the additional hitch angle offsets, the additional hitch angle offsets being related to measurable hitch angles for operating a trailer backup assist system.
20. The method of claim 19 , wherein the curve fit is one of a linear function and a higher order function.