UAV Collision Recovery Control for Attitude Reset and Descent

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Solution Overview

Problem

UAVs can experience abnormal situations such as flipping over and becoming firmly attached to obstacles after collisions, and pitch attitude deviations between the UAV's body and camera system due to wind disturbances or control errors, which affect stability and user control.

Innovation Solution

Implement a flight control method that detects collisions by reducing the rotational speeds of all motors to lower the UAV's altitude and adjust its attitude to a normal state, and adjusts the pitch attitude deviation between the camera and body to maintain a stable reference attitude.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If the UAV immediately adjusts its attitude to a normal attitude after collision, then the attitude recovery speed is improved, but the UAV may flip over and become firmly attached to the obstacle

Engineering Contradiction:
Improveattitude recovery speedVSAvoidflight stability
Core Design Contradiction:
SpeedVSReliability

Solution Approach 1:

The patent applies preliminary action by first reducing the flight altitude before adjusting the attitude. The control method detects collision through acceleration data, first commands the UAV to descend to a safe altitude, and then adjusts the attitude to normal. This sequence prevents the UAV from flipping over while recovering from collision, as the altitude reduction is performed before attitude adjustment.

Inventive Principle:
Principle #10Preliminary action

2Speed

If the UAV maintains high motor speeds during flight, then the flight altitude and responsiveness are improved, but the UAV cannot quickly lower its altitude when collision occurs

Engineering Contradiction:
Improveflight responsivenessVSAvoidaltitude control flexibility
Core Design Contradiction:
SpeedVSEase of operation

Solution Approach 1:

The patent applies dynamics by making the motor speed control adaptive rather than static. During normal flight, motors operate at high speeds for responsive flight. Upon collision detection, the control method dynamically reduces motor speeds to enable rapid altitude reduction. This dynamic adjustment allows the UAV to maintain high responsiveness during normal operation while gaining the ability to quickly lower altitude when needed.

Inventive Principle:
Principle #15Dynamics

3Device complexity

If the pitch attitude deviation between camera and body is not corrected, then the system complexity is reduced, but the photographing stability deteriorates

Engineering Contradiction:
Improvecontrol system complexityVSAvoidphotographing stability
Core Design Contradiction:
Device complexityVSStability of the object's composition

Solution Approach 1:

The patent applies feedback by implementing a closed-loop control system for pitch attitude. The control method obtains the actual pitch attitude deviation between the photographing device and the body, compares it with the reference deviation, and generates correction commands based on the error signal. This feedback mechanism maintains photographing stability by continuously correcting pitch attitude deviations without requiring complex mechanical stabilization structures.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP4578783A1Flight control method, apparatus, unmanned aerial vehicle, and storage medium
Publication Date: 2025.07.02 SZ DJI TECH CO LTD
  • EP4578783A1 patent drawingFigure 1~2A
  • EP4578783A1 patent drawingFigure 2B~3
  • EP4578783A1 patent drawingFigure 4~5B

AI summary

A flight control method, device, UAV and storage medium. The method includes: in a flight state, determining whether a UAV has collided (31); when it is determined that a collision has occurred, reducing rotation speeds of all motors in the power system of the UAV to reduce the flight altitude of the UAV, and adjusting the attitude of the UAV to a normal attitude (32). The present application can reduce the occurrence of abnormal situations in which a UAV flips over after colliding with an obstacle and finally firmly attached to the obstacle.