Radar Landing Guidance Using Reflective Markers Without GNSS
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Autonomous vehicles face challenges in precise landing and takeoff, especially in urban environments, due to degradation or loss of GNSS position information, which can lead to collisions with obstacles, as they lack secondary navigation systems and are vulnerable to signal interference and multipath errors.
Innovation Solution
A radar-based guidance and landing system that uses reflective symbols at the landing site to determine the vehicle's three-dimensional position, velocity, and attitude, allowing for accurate navigation and obstacle detection without relying on GNSS or IMU systems, by emitting and receiving radar signals to guide the vehicle safely.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If GNSS receiver is used for position determination, then navigation coverage is improved, but measurement precision deteriorates due to signal blocking and jamming in urban environments
Solution Approach 1:
The patent introduces radar as an intermediary system between the vehicle and the landing site. The radar emits signals that reflect off reflective symbols placed at the landing site, providing position information without relying on external satellite signals. This mediator system enables accurate navigation in urban environments where GNSS signals are blocked or jammed by buildings.
2Measurement precision
If optical image sensors are used for position determination, then measurement precision is improved, but reliability deteriorates due to weather impairments
Solution Approach 1:
The patent replaces optical image sensors with a radar-based electromagnetic system. Radar uses radio wave emission and reception rather than optical detection, making it immune to weather conditions such as rain, fog, or snow that would impair optical sensors. The radar signals penetrate atmospheric conditions that block visible light, ensuring reliable operation in all weather.
3Reliability
If secondary navigation systems are added to autonomous vehicles, then reliability is improved, but device complexity increases
Solution Approach 1:
The radar system serves multiple functions simultaneously: it determines the vehicle's position relative to the landing site, measures distance through signal time-of-flight, calculates relative velocity via Doppler shift, and detects obstacles in the path. This multi-functional approach provides robust navigation without requiring multiple separate specialized systems, thereby limiting the increase in complexity.
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 reliable and precise landing and takeoff operations even in conditions where GNSS is unreliable, by providing accurate positional data and obstacle detection, thereby preventing collisions and ensuring safe vehicle operations in urban environments.
Implementation Method 1
emitting, from the vehicle, a radar signal towards a landing site; receiving, at the vehicle, a radar return signal reflected from a reflective symbol at the landing site
Implementation Method 2
receiving, at the vehicle, a radar return signal reflected from a reflective symbol at the landing site
Implementation Method 3
determining a guidance vector, a distance, and a relative velocity of the with respect to the landing site using the radar return image of the reflective symbol
Data Source
AI summary
Techniques for allowing a vehicle equipped with at least one radar to take-off and land using radar return images of a landing site. The at least one radar generates radar return image(s) of the landing site, specifically of reflective symbols attached to the landing site, allowing the vehicle to orient itself to the landing site and providing information specific to the landing site. Position and velocity in relation to a landing site can be determined using at least one radar and a guidance and landing system. Using the position and velocity information, the guidance and landing system can guide the vehicle to and from the landing site and/or determine whether an obstacle requires the use of an alternate landing site.