Optical Beacon Navigation for Vehicles Using Blinking Signals
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Solution Overview
Problem
Current positioning systems for robots and unmanned vehicles, such as GPS/INS and landmark navigation, face challenges in accuracy and reliability, especially in environments with limited GPS signal and cluttered scenes, leading to errors in dead reckoning and position determination.
Innovation Solution
A landmark navigation system using optical beacons that emit or reflect signals at a predetermined frequency, where a digital camera captures image pairs with a half-blink period interval to generate difference frames, identifying pixel locations of beacons for determining vehicle position and orientation, which can be self-surveyed and integrated with other positioning systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If GPS/INS positioning system is used, then position determination capability is provided, but system cost and complexity increase significantly
Solution Approach 1:
The patent uses optical beacons as simplified copies or substitutes for complex GPS/INS infrastructure. Instead of relying on satellite-based positioning systems, the invention deploys local optical beacons that emit identifiable light patterns, allowing the vehicle to determine its position through optical recognition and triangulation methods, thereby eliminating the need for expensive GPS/INS hardware and differential correction data systems
Solution Approach 2:
The optical beacons are described as inexpensive deployable elements that can be placed throughout the environment. Rather than investing in costly permanent positioning infrastructure, the system uses simple, low-cost optical beacons that can be easily deployed and replaced, providing accurate positioning without the high capital expenditure required for GPS/INS systems
2Ease of operation
If INS techniques are used for dead reckoning, then relative movement can be determined, but error accumulates over time
Solution Approach 1:
The patent implements a feedback mechanism where the vehicle continuously observes optical beacons and compares its observed position against the known beacon locations. This provides periodic correction data that resets the accumulated dead reckoning errors, allowing the system to maintain accurate positioning over extended periods without relying solely on INS integration which drifts over time
Solution Approach 2:
The system pre-deploys optical beacons at known locations throughout the environment before the vehicle begins operation. This preliminary setup creates a reference framework that the vehicle can use to continuously correct its position estimates, preventing error accumulation by providing frequent absolute position references rather than relying on continuous integration of relative motion measurements
3Measurement precision
If landmark navigation with high contrast bar code or dot pattern is used, then position computation can be performed, but reliable identification in cluttered scenes becomes difficult
Solution Approach 1:
The patent employs blinking optical beacons that emit light in periodic on-off patterns. This temporal modulation allows the vehicle's imaging system to distinguish beacons from static background clutter by detecting the characteristic blinking pattern, significantly improving landmark identification reliability in cluttered scenes compared to static high-contrast patterns
Solution Approach 2:
The optical beacons utilize changes in optical intensity (brightness on and off) as a temporal signature. This dynamic optical property allows the vehicle to reliably identify beacons by detecting the characteristic brightness variations over time, making it easier to distinguish beacons from background elements that do not exhibit this periodic intensity change
4Measurement precision
If sufficient illumination is provided for landmark navigation, then position determination accuracy improves, but system cost and power consumption increase
Solution Approach 1:
Instead of providing continuous illumination, the patent uses periodically blinking optical beacons. This allows the vehicle's imaging system to capture images during the brief illumination windows and use image differencing techniques to identify the blinking beacon patterns, achieving accurate position determination with minimal illumination energy consumption compared to continuous lighting
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 approach provides a cost-effective and accurate navigation system that can maintain precision without relying on GPS, reducing dead reckoning errors and enhancing reliability in various environments, including indoor and outdoor applications.
Implementation Method 1
optical beacons emit or reflect an optical signal at a predetermined blink frequency
Implementation Method 2
at least one imaging device on the vehicle, such as a digital camera, to capture images in the field of operation
Data Source
AI summary
A system and method for landmark navigation employing optical beacons deployed at locations throughout a field of operation of a vehicle. The optical beacons emit or reflect an optical signal at a predetermined blink frequency. The locations of the optical beacons may or may not be known to the vehicle. At least one imaging device on the vehicle, such as a digital camera, captures images in the field of operation, and in particular a pair of image frames such that the time interval between the image frames of the pair is equal to one-half of the blink period of the optical signal. Data is generated that represents a difference frame between two image frames captured by the imaging device. Pixel locations of optical beacons in the difference frame are identified. The position and orientation of the vehicle is determined from data representing pixel locations of optical beacons in the difference frame.