UAV Visual Marker Navigation in GPS-Denied Surveillance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Unmanned aerial vehicles (UAVs) face challenges in navigating environments with weak or unreliable GPS signals, which hinders their autonomous navigation and surveillance capabilities.
Innovation Solution
The use of visual markers with unique patterns, such as ribbons with squares of different colors or AprilTags, QR codes, and barcodes, that UAVs can detect using vision sensors to determine their position and orientation within a three-dimensional coordinate system, allowing for autonomous navigation and surveillance even in GPS-denied environments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If GPS signals are used for UAV navigation, then navigation accuracy is improved, but reliability deteriorates in environments with weak or unreliable GPS signals
Solution Approach 1:
The patent introduces visual markers as an intermediary reference system between the UAV and the environment. These markers serve as mediators that provide position and orientation information without requiring GPS signals. The markers are detected by the UAV's vision sensors and used to calculate the UAV's location and orientation in three-dimensional space, thereby resolving the contradiction between maintaining navigation accuracy and ensuring reliability in GPS-denied environments.
2Reliability
If visual markers are introduced for navigation, then navigation reliability in GPS-denied environments is improved, but device complexity increases
Solution Approach 1:
The navigation system is segmented into independent components: pre-placed visual markers in the environment and a detection system on the UAV. The markers are simple geometric patterns that can be independently detected and processed. This segmentation allows the complex navigation problem to be broken down into simpler tasks of marker detection, pattern recognition, and coordinate calculation, thereby managing system complexity while maintaining reliability.
3Measurement precision
If vision sensors are used to detect visual markers, then positioning accuracy in three-dimensional space is improved, but energy consumption increases
Solution Approach 1:
The visual markers are pre-placed and pre-configured in the environment before the UAV arrives. Their positions and orientations are known in advance and stored in the system. This preliminary action eliminates the need for the UAV to actively search or create reference points during flight, reducing real-time computational burden and energy consumption while maintaining high positioning accuracy through precise marker detection and coordinate calculation.
Data Source
AI summary
A method of controlling an unmanned aerial vehicle (UAV) in an environment includes detecting, with aid of a sensor coupled to the UAV and while the UAV is in flight, a signal that is emitted from and uniquely identifying a locating marker; determining, with aid of a processor, a sequence of actions to control the UAV in response to a plurality of instructions encoded in the locating marker and communicated by the signal; and controlling, with aid of the processor, the UAV to effect the sequence of actions according to a specified time interval included in the plurality of instructions. The specified time interval indicates a wait time before the UAV effects the sequence of actions.