Aircraft-Mounted Optical Speed Detection With Terrain-Map Checks
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing optical speed detection systems face practical implementation challenges, particularly in detecting speeding violations, due to the need for rapid and reliable measurements that are not adequately addressed by current methods.
Innovation Solution
A method using an optical camera mounted on an aircraft to measure vehicle speed by estimating the vehicle's position in two instants, incorporating georeferencing, topographic mapping, and error modeling to ensure accuracy, with validation steps to confirm the vehicle is on a road or street, and utilizing RTK and DGPS for precise positioning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If optical camera based speed detection is used, then passive detection without radiation emission is achieved, but measurement reliability and speed are insufficient for practical speeding violation detection
Solution Approach 1:
The patent applies preliminary action by pre-establishing a topographic map of the detection area with marked roads and streets before actual speed detection. This pre-processing of spatial information allows the system to quickly validate whether detected vehicles are on valid detection zones, eliminating the need for real-time complex environment analysis and enabling rapid reliable measurements for speeding violation detection.
2Measurement precision
If position estimation using line of sight intersection is used, then speed measurement is achieved, but terrain elevation differences cause measurement errors
Solution Approach 1:
The patent introduces an intermediary validation mechanism using pre-stored topographic map data. Instead of directly trusting the line of sight intersection position estimation, the system uses the topographic map as an intermediary to verify whether the estimated position falls on a valid road or street. This intermediary validation step filters out position estimation errors caused by terrain elevation differences, ensuring measurement precision.
3Measurement precision
If iterative validation with topographic map is implemented, then measurement accuracy is improved, but computational complexity increases
Solution Approach 1:
The patent reduces algorithmic complexity through preliminary action by pre-processing and storing topographic map data with marked roads and streets before detection operations. This pre-computation transforms the complex iterative validation problem into a simpler query operation during actual speed detection, maintaining high measurement precision while minimizing real-time computational complexity.
Data Source
Figure 1~2
Figure 3~4
Figure 5~6
AI summary
The present invention relates to a method for determining the speed of a vehicle (V, Target) (C) by means of using an optical camera (1) by means of the following steps of determining the height (ΔH) of the camera (1) with respect to the ground, the inclination (β) of the line of sight (LOS) of the camera (1), and iteratively determining the intersection between the line of sight (LOS) and a horizontal line (x0x1, x1'x2, x2'x3... ) passing through the last projection (x0, x1', x2',...xn') to obtain an approximate value (x1, x2,...xn) of the position of the vehicle (V, Target), determining from a map (DTM) the vertical projection (x1', x2',...xn') over the ground of the approximate value (x1, x2,...xn), and thereby obtaining the terrain elevation (ΔZ) of the vertical projection (x1', x2',...xn') with respect to the horizontal line (x0x1, x1'x2, x2'x3...), comparing the terrain elevation (ΔZ) with respect to a predetermined threshold value.