UAV Altitude Control Using Terrain-Relative Flight Restrictions
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Solution Overview
Problem
Existing altitude restrictions for UAVs are often set relative to fixed levels like sea level, disregarding terrain elevation, leading to inadequate control over flight heights in varying terrain and cities, potentially causing encroachment on controlled airspace or failure to reach necessary altitudes for tasks like surveillance and aerial photography.
Innovation Solution
A method and system that dynamically adjust altitude restrictions based on local ground level and terrain elevation, using sensors like GPS, ultrasonic, or lidar to ensure the UAV complies with altitude limits relative to ground level, allowing for real-time adjustments of altitude ceilings and floors to maintain safe and legal flight paths.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If altitude restrictions are set relative to fixed levels like sea level, then the control system is simple and easy to implement, but the UAV may encroach on controlled airspace or fail to reach necessary altitudes in varying terrain
Solution Approach 1:
The patent implements dynamic altitude restrictions that adjust based on terrain elevation data. Instead of using fixed altitude limits, the system continuously modifies the maximum altitude ceiling relative to the local ground level, allowing the UAV to maintain safe distances from terrain while complying with airspace regulations in varying topographic conditions
Solution Approach 2:
The system incorporates feedback mechanisms by continuously monitoring the UAV's position, comparing it with terrain elevation data, and adjusting altitude restrictions in real-time. This closed-loop control ensures the UAV maintains appropriate clearance from terrain while adhering to controlled airspace boundaries
2Device complexity
If altitude restrictions are set relative to fixed levels, then the device complexity is reduced, but the UAV cannot adapt to complex terrain or large altitude gradients
Solution Approach 1:
The system transitions from static to dynamic altitude restrictions by incorporating real-time terrain elevation data. The maximum altitude ceiling is continuously adjusted based on the UAV's horizontal position and local terrain height, enabling adaptation to complex terrain features, mountains, valleys, and urban environments with varying ground levels
Solution Approach 2:
The patent changes the reference parameter for altitude restrictions from a fixed sea-level baseline to a dynamic terrain-relative baseline. By modifying how altitude is calculated and restricted based on local elevation data, the system achieves versatility across diverse terrains without requiring fundamentally different control architectures
3Ease of operation
If altitude restrictions disregard ground level, then the restriction system is simpler to implement, but the UAV may fail to reach allowed heights needed for surveillance and aerial photography
Solution Approach 1:
The system dynamically calculates the maximum allowable altitude as a function of local terrain elevation rather than using a fixed ceiling. This allows the UAV to reach higher absolute altitudes when flying over low-lying terrain while maintaining appropriate relative clearance, thereby enabling surveillance and photography tasks at necessary heights without compromising safety
Solution Approach 2:
The system performs preliminary calculations of terrain elevation and adjusts altitude restrictions before the UAV reaches specific geographic locations. This proactive adjustment ensures the UAV can plan and execute flight paths to necessary altitudes for task completion while automatically complying with terrain-relative safety margins
Data Source
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AI summary
Systems, methods, and devices are provided for providing flight response to flight-restricted altitudes. The altitude of an unmanned aerial vehicle (UAV) may be compared with an altitude restriction. If needed a flight-response measure may be taken by the UAV to prevent the UAV from flying in a restricted altitude. The altitude measurement of the UAV and/or altitude restriction of the UAV may be modified for improved performance. Different flight-response measures may be taken depending on preference and the rules of a jurisdiction within which the UAV falls.