Monocular Camera Parking Distance Measurement Adaptation
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Solution Overview
Problem
Conventional techniques for measuring the distance from a moving vehicle to an object using a monocular camera suffer from inaccuracies, particularly when the vehicle is stationary or just starting to move, as they require sufficient parallax between images, which may not be available in these conditions.
Innovation Solution
A vehicle parking support device that selects between two distance measurement methods based on the amount of vehicle movement, using either a ground contact position determination technique for low movement or a moving stereo technique for higher movement, to optimize distance measurement accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the moving stereo technique is used for distance measurement, then measurement precision is improved when the vehicle is moving, but the technique cannot be performed with sufficiently high precision when the vehicle is not running or immediately after start of running due to insufficient parallax
Solution Approach 1:
The patent dynamically switches between two distance measurement methods based on the vehicle's movement state. When the vehicle is stationary or moving minimally, the ground contact position determination technique is used. When the vehicle moves sufficiently, the moving stereo technique is employed. This dynamic adaptation resolves the contradiction by selecting the appropriate method for each operational condition, ensuring measurement precision across all scenarios.
Solution Approach 2:
The patent changes the measurement parameter approach based on vehicle movement. The ground contact position determination uses geometric calculation from single-image coordinates, while the moving stereo technique uses triangulation from multiple images. By changing the measurement parameter method according to vehicle movement conditions, the system achieves high precision in both stationary and moving states.
2Ease of operation
If the ground contact position determination technique is used, then distance measurement can be performed from a single image, but measurement accuracy is greatly affected by error in the pixel position of the detected object
Solution Approach 1:
The patent introduces an intermediate selection mechanism that determines which measurement method to use based on vehicle movement conditions. This intermediary approach allows the system to overcome the pixel position error limitation of ground contact position determination by switching to the moving stereo technique when vehicle movement provides sufficient parallax, thereby improving measurement precision while maintaining operational simplicity.
3Ease of manufacture
If a monocular camera is used for object detection, then cost is reduced and mounting position restrictions are minimized, but distance measurement accuracy is compromised compared to stereo cameras
Solution Approach 1:
The patent performs preliminary action by utilizing vehicle movement itself to create the necessary parallax for accurate distance measurement. Instead of requiring a complex stereo camera system, the system uses the vehicle's natural movement between image captures to achieve stereo-like measurement precision with a simple monocular camera, thereby maintaining ease of manufacture while improving measurement precision.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution enhances the accuracy of distance measurement from a moving vehicle to an object by selecting the appropriate method based on movement conditions, thereby improving the precision of parking support systems.
Implementation Method 1
the moving stereo technique is a technique for estimating the distance from a vehicle to an object, on the basis of the amount of movement of the vehicle and a plurality of sets of image data captured by a monocular camera before and after the movement of the vehicle
Data Source
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AI summary
A vehicle parking support device includes a processing circuit that performs: a first process of acquiring a first image at a first time and a second image at a second time later than the first time from a monocular camera mounted on a vehicle; a second process of calculating an amount of movement of the vehicle, on the basis of a sensor value acquired during a measurement period between the first time and the second time; a third process of outputting a result of distance measurement using a first distance measurement method for performing distance measurement using the first image or the second image, or a second distance measurement method for performing distance measurement using both the first image and the second image, depending on the amount of movement; and a fourth process of outputting a result of calculation of a route for guiding the vehicle to a parking space, on the basis of the result of distance measurement.