Trailer Hitch Ball Localization Using Single-Camera Height Estimation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing vehicle trailer hitching systems face challenges in accurately determining the height and ground position of the hitch ball using a single rearward viewing camera, requiring additional ground truth distance for precise 3D positioning, which can lead to errors in maneuvering the vehicle during hitching operations.
Innovation Solution
The system employs a CMOS imaging array camera with an electronic control unit (ECU) that processes image data to determine the hitch ball's position, angle, and height by utilizing camera and hitch lateral offsets, and camera projection geometry, allowing for the calculation of the hitch ball's ground position, and uses feature detection algorithms or AI to refine these calculations across multiple frames.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single rearward viewing camera is used to determine hitch ball position, then the device complexity is reduced, but the measurement precision of hitch ball height and ground position deteriorates
Solution Approach 1:
The system transitions from 2D image coordinates to 3D spatial coordinates by incorporating the known physical dimensions of the camera (lens focal length, sensor dimensions, mounting position) to calculate real-world hitch ball height and ground position. This dimensional transformation enables precise measurement using a single camera without requiring additional ground truth distances.
Solution Approach 2:
The camera system uses its own inherent physical properties (focal length, sensor size, mounting geometry) as reference measurements to calculate hitch ball position. The system serves itself by utilizing the camera's built-in calibration data and geometric relationships rather than requiring external reference objects or multiple ground truth measurements.
2Measurement precision
If additional ground truth distance is used for precise 3D positioning, then the measurement precision improves, but the ease of operation deteriorates
Solution Approach 1:
The system pre-stores the camera's physical dimensions (focal length, sensor dimensions, mounting position relative to vehicle centerline) as calibration data before operation. This preliminary configuration enables real-time calculation of hitch ball position during hitching maneuvers without requiring operators to manually measure or input ground truth distances, maintaining both precision and ease of operation.
3Measurement precision
If camera lateral offset from vehicle centerline is utilized, then the measurement precision of hitch ball position improves, but the device complexity increases
Solution Approach 1:
The system uses the camera's own mounting geometry (lateral offset from vehicle centerline, height above ground, angular orientation) as intrinsic reference data. These physical properties are pre-calibrated and stored in the system, enabling automatic calculation of hitch ball ground position without requiring external reference objects or complex additional sensors.
Data Source
AI summary
A vehicular trailer hitching assist system includes a camera disposed at a rear portion of a vehicle and viewing a hitch ball of a trailer hitch of the vehicle. The system determines a position of the hitch ball within frames of image data, and determines an angle based on a lateral offset distance of the camera relative to the longitudinal centerline of the vehicle and a lateral offset distance of the hitch ball relative to the longitudinal centerline of the vehicle. The system determines height of the hitch ball based on the determined angle and the lateral offset distance of the camera and the lateral offset distance of the hitch ball. The system determines a hitch-ball ground position based on the determined height of the hitch ball. The system utilizes the determined height of the hitch ball and the determined hitch-ball ground position during a hitching maneuver of the vehicle.