Vehicle Speed Detection Using Dynamic Image Capture Intervals

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Solution Overview

Problem

Existing vehicle speed measurement systems face challenges in providing accurate secondary evidence, especially at the limits of the speed measurement range, due to conflicting requirements for time intervals between image recordings, which can result in errors or inability to calculate speed for vehicles moving at high or low speeds.

Innovation Solution

A method that adjusts the time interval between image recordings based on the measured vehicle speed, using partial image information from the first image to quickly capture a second image, allowing for faster reaction times and omitting the need for separate sensors, and adapts the amount of image information read out to match the speed, ensuring accurate speed calculation and proof photography.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a fixed time interval is used between image recordings, then the system is simple to operate, but the speed calculation accuracy deteriorates at the limits of the speed measurement range

Engineering Contradiction:
Improvesimplicity of time interval specificationVSAvoidspeed calculation accuracy
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent applies dynamics by making the time interval between image recordings variable rather than fixed. The control unit adapts the time interval based on the measured speed value: shorter intervals for high speeds and longer intervals for low speeds. This dynamic adjustment ensures that vehicles traverse a sufficient distance between recordings for accurate speed calculation, regardless of their speed, thereby resolving the contradiction between operational simplicity and measurement precision.

Inventive Principle:
Principle #15Dynamics

2Speed

If a short time interval is used between image recordings, then high-speed vehicles remain in the field of vision, but the image resolution is insufficient for accurate speed calculation of slow-moving vehicles

Engineering Contradiction:
Improvevehicle speed range coverageVSAvoidspeed calculation accuracy
Core Design Contradiction:
SpeedVSMeasurement precision

Solution Approach 1:

The system dynamically adjusts the time interval between image recordings based on the measured speed. For high-speed vehicles, shorter intervals ensure they remain in the field of vision. For low-speed vehicles, longer intervals allow them to traverse sufficient distance for accurate speed calculation. This dynamic adaptation resolves the contradiction between capturing high-speed vehicles and maintaining accuracy for slow-moving vehicles.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the time interval parameter based on the measured speed value. By adjusting this critical parameter dynamically, the system optimizes the balance between keeping high-speed vehicles in view and ensuring sufficient movement distance for accurate speed calculation of all vehicles, thereby resolving the measurement precision issue across different speed ranges.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If the camera reads out all image information, then the image quality is high, but the reaction time is too slow for high-speed vehicles

Engineering Contradiction:
Improveimage qualityVSAvoidcamera reaction time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent extracts only the essential image information needed for speed calculation rather than reading out the entire image. The control unit determines which image areas contain relevant vehicle information and reads out only those specific regions. This extraction approach maintains sufficient image quality for speed measurement while dramatically reducing the readout time, enabling the camera to capture high-speed vehicles before they leave the field of vision.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The system performs partial action by reading out only the necessary portions of the image data required for speed calculation. Instead of processing the complete image, the control unit identifies and extracts only the relevant image areas containing vehicle information. This partial processing approach achieves the necessary measurement precision while minimizing the time loss during readout, making the system responsive to high-speed vehicles.

Inventive Principle:
Principle #16Partial or excessive action

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

Enables accurate and efficient calculation of vehicle speed, providing reliable secondary evidence for both high-speed and low-speed vehicles, reducing legal challenges and operational costs by integrating with existing hardware and improving image resolution for identification purposes.

Implementation Method 1

an FM-CW radar measuring device for measuring the vehicle speed

Methodology Applied
Scientific EffectRadar: Radar

Implementation Method 2

a digital recording unit with a CCD image sensor (Charge Coupled Device) for recording the digital image

Methodology Applied
Scientific EffectPhotoelectric Effect: Photoelectric Effect

Data Source

PatentEP2338062B1Method and system for determining a vehicle speed
Publication Date: 2017.11.29 SIEMENS AG OESTERR
  • EP2338062B1 patent drawingFigure 1
  • EP2338062B1 patent drawingFigure 2
  • EP2338062B1 patent drawingFigure 3

AI summary

The invention relates to a method for determining the speeds of vehicles (2) passing a detection unit (1), wherein the speed of the passing vehicles is measured by a measuring device (3), and in the event that the reading of the speed of a vehicle exceeds a specified maximum speed an imaging and processing device is prompted to take a first picture and with some time delay (?T) a second picture of said vehicle using a digital image sensor, so as to calculate a calculated value from said two images, and wherein in the determination of the speed of the detection unit the reading and the calculated value are taken into consideration, wherein the time delay (?T) is specified as a function of the reading of the speed. In order to speed up the signal processing operation, only part of the image information, such as only every second, third, or fourth line, is used for determining the speed.