Aircraft Ground Slope Detection Using Rangefinders and Attitude Data

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Solution Overview

Problem

Current technologies for detecting ground slope during aircraft landing, especially for smaller-scale platforms like drones, are costly, difficult to maintain, and limited by size and weight, making them unsuitable for safe landing at unknown sites.

Innovation Solution

A ground slope detection method that calculates a unique plane from at least three downward-looking distance detection points in the aircraft's body coordinate system, using three-dimensional attitude data and distance data from rangefinders, and generates a warning signal for excessive ground slope based on the included angle with the geodetic horizontal plane.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a laser radar-based scanner and computing system are installed on the aircraft to obtain accurate radar point cloud data for terrain detection, then measurement precision is improved, but device complexity, weight, and cost increase

Engineering Contradiction:
Improveterrain detection precisionVSAvoidsystem hardware complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts only the essential function of terrain detection from the complex laser radar system. Instead of using a full laser radar scanner, it separates the terrain detection function and implements it through a simpler combination of rangefinder and attitude sensor data processing, eliminating unnecessary hardware complexity while maintaining detection precision

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical laser radar scanning system with a computational approach. Instead of using physical laser scanning hardware, it substitutes a mathematical model that calculates terrain slope by processing data from existing sensors (rangefinder and attitude sensors), thereby eliminating the need for complex mechanical scanning systems

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Measurement precision

If a laser radar-based scanner and computing system are installed on the aircraft to obtain accurate radar point cloud data for terrain detection, then measurement precision is improved, but weight increases

Engineering Contradiction:
Improveterrain detection precisionVSAvoidsystem weight
Core Design Contradiction:
Measurement precisionVSWeight of moving object

Solution Approach 1:

The patent extracts only the essential function of terrain detection from the complex laser radar system. Instead of using a full laser radar scanner, it separates the terrain detection function and implements it through a simpler combination of rangefinder and attitude sensor data processing, eliminating unnecessary hardware weight

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical laser radar scanning system with a computational approach. Instead of using physical laser scanning hardware, it substitutes a mathematical model that calculates terrain slope by processing data from existing sensors (rangefinder and attitude sensors), thereby eliminating the need for heavy mechanical scanning systems

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Measurement precision

If a laser radar-based scanner and computing system are installed on the aircraft to obtain accurate radar point cloud data for terrain detection, then measurement precision is improved, but cost increases

Engineering Contradiction:
Improveterrain detection precisionVSAvoidsystem cost
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent extracts only the essential function of terrain detection from the complex laser radar system. Instead of using a full laser radar scanner, it separates the terrain detection function and implements it through a simpler combination of rangefinder and attitude sensor data processing, eliminating unnecessary hardware cost

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical laser radar scanning system with a computational approach. Instead of using physical laser scanning hardware, it substitutes a mathematical model that calculates terrain slope by processing data from existing sensors (rangefinder and attitude sensors), thereby eliminating the need for expensive mechanical scanning systems

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

4Measurement precision

If a laser radar-based scanner and computing system are installed on the aircraft to obtain accurate radar point cloud data for terrain detection, then measurement precision is improved, but ease of operation and maintenance worsen

Engineering Contradiction:
Improveterrain detection precisionVSAvoidsystem ease of operation
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The patent extracts only the essential function of terrain detection from the complex laser radar system. Instead of using a full laser radar scanner, it separates the terrain detection function and implements it through a simpler combination of rangefinder and attitude sensor data processing, eliminating unnecessary operational complexity

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical laser radar scanning system with a computational approach. Instead of using physical laser scanning hardware, it substitutes a mathematical model that calculates terrain slope by processing data from existing sensors (rangefinder and attitude sensors), thereby eliminating the need for complex mechanical scanning systems that require specialized operation and maintenance

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentEP4564119A1Ground slope measurement method and device, and computer-readable storage medium
Publication Date: 2025.06.04 EHANG INTELLIGENT EQUIP GUANGZHOU CO LTD
  • EP4564119A1 patent drawingFigure 1~2
  • EP4564119A1 patent drawingFigure 3~4
  • EP4564119A1 patent drawingFigure 5~6

AI summary

A ground slope detection method, device and computer-readable storage medium. The method includes: (S1) during landing of an aircraft, calculating a unique plane of at least three downward-looking distance detection points in a body coordinate system of the aircraft according to three-dimensional attitude data of the aircraft and distance data of at least three downward-looking rangefinders provided on the aircraft; (S2) calculating a rotation matrix of the body coordinate system to a geodetic coordinate system by the three-dimensional attitude data, and calculating a first unit normal vector of the unique plane in the geodetic coordinate system according to the rotation matrix; and (S3) calculating an included angle between a second unit normal vector of a geodetic horizontal plane in the geodetic coordinate system and the first unit normal vector, and generating a warning signal of excessive ground slope when the included angle is greater than or equal to a preset threshold. The method reduces the system hardware cost and maintenance and use difficulty of slope detection, providing effective protection for the safety of aircraft landing.