Trailer Backup Trajectory Overlay with Speed-Based Prediction Switching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing camera systems struggle to accurately predict trailer trajectory during reversing maneuvers due to inaccuracies in determining trailer angular velocity and steering angle, especially when vehicle speed is zero, leading to large prediction errors and potential collisions.
Innovation Solution
A method that combines image-based trailer tracking with steering angle changes to revise trailer trajectory, using image analysis to determine trailer location and angle change rate, and switching to a kinematic model for steering corrections when vehicle speed is low, ensuring accurate trajectory prediction even at zero speed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If image-based trailer tracking is used to determine trajectory, then trailer location and angle change rate can be detected, but prediction accuracy deteriorates when vehicle speed is zero or trailer angular velocity is large
Solution Approach 1:
The system dynamically switches between two different prediction models based on vehicle speed parameters. When vehicle speed is above a threshold, the image-based tracking model is used. When vehicle speed drops below the threshold, the system transitions to a steering angle-based kinematic model. This parameter-based switching resolves the contradiction by adapting the prediction method to the current operating conditions, ensuring reliability across all speed ranges including zero speed.
Solution Approach 2:
The steering angle sensor acts as an intermediary measurement source that becomes the primary trajectory prediction method when image-based tracking becomes unreliable at zero speed. The system uses the steering angle input combined with vehicle speed to calculate expected trailer motion through kinematic relationships, providing a reliable prediction mechanism that complements the image-based system.
2Reliability
If steering angle is used to calculate trailer trajectory, then trajectory can be predicted at zero speed, but accuracy deteriorates due to simplistic virtual steering angle assumptions
Solution Approach 1:
The system merges two different measurement approaches - image-based trailer tracking and steering angle-based kinematic modeling - into a unified trajectory prediction system. Each method compensates for the other's weaknesses: the image-based method provides accuracy during motion while the steering angle method provides reliability at zero speed. The fusion of these methods resolves the contradiction by combining their respective strengths.
Solution Approach 2:
The system dynamically adjusts which prediction model is active based on real-time vehicle speed conditions. Rather than using a static or simplistic virtual steering angle assumption throughout, the system adapts its prediction methodology according to the current operating state, switching between image-based and steering-based models to maintain both reliability and precision across all conditions.
3Device complexity
If previous prediction model is used during reversing maneuvers, then computation is simpler, but accuracy deteriorates due to constant angular velocity assumption
Solution Approach 1:
The system performs preliminary determination of vehicle speed and trailer angular velocity to select the appropriate prediction model before executing trajectory calculation. This preliminary assessment allows the system to choose between the simpler image-based model and the more accurate dynamic model based on current conditions, resolving the contradiction by applying model selection intelligence that balances computational simplicity with measurement precision.
Data Source
Figure 1A
Figure 1B
Figure 2~3
AI summary
A method of determining a trailer trajectory for a trailer includes the steps while the trailer is moving: determining a trailer location based upon at least one captured image, determining a trailer angle change rate based upon the at least one captured image, determining a trailer trajectory based upon the trailer location and the trailer angle change rate, and displaying an overlay related to the trailer trajectory. While the trailer is below a threshold speed the method includes the steps of: determining a steering change, revising the trailer trajectory based upon the steering change, and displaying a modified overlay related to the trailer trajectory based upon the steering change.