Radio Altimeter Approach Speed Detection for Aircraft
Solution Overview
Problem
Current Ground Proximity Warning Systems (GPWS) and Enhanced-GPWS systems are inadequate in detecting collision risks with the ground, especially in unknown terrain and when GPS or Galileo systems are jammed, leading to potential collisions.
Innovation Solution
A radio altimeter device with a transmission-reception antenna system and processing unit that measures the aircraft's height and speed of approach to the ground, capable of detecting collision risks and issuing warnings, independent of GPS or Galileo systems, by emitting and receiving radio waves and calculating the aircraft's height and approach speed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of information
If E-GPWS system uses GPS/Galileo positioning and ground maps, then aircraft location awareness is improved, but system reliability deteriorates when GPS is jammed or terrain is unknown
Solution Approach 1:
The patent introduces a radio altimeter as an intermediary system that provides direct radio wave-based height measurement independent of GPS satellites. This mediator system bypasses the jammed GPS/Galileo positioning infrastructure and delivers reliable altitude information through radio wave reflection from the ground, ensuring continuous operation in denied or unknown terrain environments
Solution Approach 2:
The system changes the measurement parameter from satellite-based positional coordinates (latitude, longitude, altitude) to direct radio wave-based height above ground. This parameter transformation eliminates dependency on GPS signal availability and ground map databases, providing reliable height information regardless of terrain familiarity or satellite jamming conditions
2Device complexity
If GPWS system uses only height information, then system simplicity is maintained, but collision detection capability deteriorates
Solution Approach 1:
The system performs preliminary calculation of approach speed by continuously monitoring height changes over time before a potential collision occurs. This advance computation of vertical velocity enables the system to detect dangerous descent rates and issue warnings earlier, improving collision detection capability while maintaining the simplicity of the radio altimeter-based architecture
3Measurement precision
If radio altimeter measures only height, then measurement function is simple, but collision risk detection capability deteriorates
Solution Approach 1:
The system implements feedback by continuously monitoring height measurements over time and calculating the rate of change (approach speed). This feedback mechanism transforms static height data into dynamic collision risk assessment, enabling the system to detect dangerous approach rates and issue timely warnings while maintaining the simplicity and precision of radio altimeter measurements
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
Enhances collision risk detection by considering the presence of obstacles on the ground, ensuring operational effectiveness in all circumstances, including military applications where terrain is unknown and GPS systems are unreliable, and integrates height measurement, approach speed calculation, and warning functions into a single device.
Implementation Method 1
a transmission-reception antenna system able to transmit a radioelectric wave generated by a radioelectric wave generator and to receive the radio wave reflected by the ground
Implementation Method 2
the processing unit is able to record the time elapsed between the emission of the radiofrequency wave by the antenna and the reception of the radiofrequency wave by the same antenna
Data Source
Figure 1~2
AI summary
The method involves acquiring a first height of an aircraft (10) with respect to a ground at a first instant and a second height of the aircraft with respect to the ground at a second instant. A time interval between the height acquisition instants is recorded, and a speed of approach of aircraft towards the ground is calculated. The approach speed is compared with a threshold speed value. A risk of collision of the aircraft with the ground is detected when ground approach speed of the aircraft is greater than the threshold speed. An independent claim is also included for a device for securing an aircraft flying over a ground.