Vehicle Following Distance Measurement Using Projected Laser Dots
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current vehicle distancing systems are complex and costly, requiring expensive equipment to determine safe following distances between vehicles, and there is a need for a more cost-effective solution that can accurately calculate this distance without relying on time-of-flight measurements.
Innovation Solution
A vehicle system utilizing two infrared laser modules to project dots onto a preceding vehicle, a night vision camera to detect these dots, and a controller to calculate the distance using linear interpolation based on pixel widths and known ranges, facilitating adaptive cruise control and automated emergency braking.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If radar and laser sensors are used to detect objects and determine following distance, then measurement precision is improved, but device complexity and cost increase
Solution Approach 1:
The patent replaces complex radar and laser time-of-flight measurement systems with a simpler optical system using infrared laser modules and a camera. Instead of measuring time of flight, the system projects laser dots onto the preceding vehicle and uses perspective geometry to calculate distance from the apparent separation of dots in the camera image, thereby reducing device complexity while maintaining measurement precision
Solution Approach 2:
The patent uses a camera to capture an optical copy (image) of the laser dots projected onto the preceding vehicle. This optical copy allows the system to determine distance through image processing and geometric calculation rather than direct physical measurement, simplifying the overall system architecture
2Measurement precision
If radar and laser sensors are used to detect objects and determine following distance, then measurement precision is improved, but equipment cost increases
Solution Approach 1:
The patent employs inexpensive infrared laser modules and a standard camera instead of expensive radar or time-of-flight laser sensors. These lower-cost components achieve the same measurement function through a different approach (perspective geometry rather than time measurement), making the system more economically viable while maintaining adequate measurement precision
Solution Approach 2:
The patent substitutes expensive time-of-flight measurement hardware with a cheaper optical imaging system. By using the camera to capture laser dot positions and applying perspective projection mathematics, the system achieves distance measurement capability at a fraction of the cost of traditional radar or laser ranging systems
3Measurement precision
If time-of-flight measurements are used to determine distance, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent replaces time-of-flight measurement mechanisms with a geometric calculation approach. Instead of measuring the time for light to travel to and from the target, the system projects laser dots onto the target, captures their positions with a camera, and calculates distance using perspective projection geometry, thereby eliminating the need for precise time measurement hardware and reducing system complexity
Solution Approach 2:
The patent transitions from measuring distance in the time domain (time-of-flight) to the spatial domain (image coordinates). By projecting laser dots onto the preceding vehicle and measuring their apparent separation in the camera image plane, the system converts a temporal measurement problem into a spatial geometric problem, simplifying the measurement system
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
This solution provides a cost-effective method for determining following distances between vehicles, enabling accurate operation of driver assistance systems like adaptive cruise control and automated emergency braking without the need for expensive equipment, offering real-time distance updates and improved safety.
Implementation Method 1
a first laser module configured to emit a first light beam and project a first dot onto a preceding vehicle, a second laser module configured to emit a second light beam and project a second dot onto the preceding vehicle
Implementation Method 2
the first and second laser modules are infrared laser modules
Implementation Method 3
the camera is a night vision camera configured to detect infrared light emitted from the first and second infrared laser modules
Data Source
AI summary
A vehicle includes a first laser module configured to emit a first light beam and project a first dot onto a preceding vehicle, a second laser module configured to emit a second light beam and project a second dot onto the preceding vehicle, a camera configured to generate a digital image of the first and second dots projected onto the preceding vehicle, and a controller configured to determine, from the digital image, a width between the first and second dots, and subsequently determine a following distance between the vehicle and the preceding vehicle based on linear interpolation using the determined width.