AAV Propeller Contact Detection for Rapid Safety Shutdown

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Solution Overview

Problem

Automated aerial vehicles (AAVs) pose a risk due to the danger posed by their high-speed propellers, which can harm humans, pets, or other animals if contact is made while the propellers are rotating, and existing technologies do not effectively address the issue of propeller safety.

Innovation Solution

The implementation of a control system that detects objects within a selected safety perimeter of the propeller and automatically stops the propeller using various stopping mechanisms, such as removing current, reversing polarity, deploying a stop bar, or disengaging the propeller, to prevent harm.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the propeller rotates at high speed to provide thrust, then the productivity and speed of the AAV are improved, but the harmful factors increase due to the danger of contact with the high-speed propeller

Engineering Contradiction:
Improvethrust generation efficiencyVSAvoidharm from propeller contact
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The safety system performs preliminary detection of objects within the safety perimeter before propeller contact occurs. The control system continuously monitors the area around the propeller and prepares stopping mechanisms in advance, enabling the propeller to be stopped immediately upon detecting potential contact, thus preventing harm while maintaining high-speed operation

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent introduces a safety system comprising sensors, control logic, and stopping mechanisms as an intermediary between the high-speed propeller and surrounding objects. This intermediary system detects objects and activates stopping actions to prevent direct contact, allowing the propeller to maintain high speed for productivity while eliminating the harmful contact risk

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If the propeller is stopped quickly upon detecting an object, then the safety and reliability are improved, but the loss of time occurs due to interruption of thrust

Engineering Contradiction:
Improvesafety against propeller contactVSAvoidthrust interruption duration
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The control system continuously monitors the safety perimeter and pre-positions stopping mechanisms (such as electromagnetic brakes or mechanical stops) in ready states. When an object is detected, the pre-prepared stopping system activates immediately, minimizing the time required to stop the propeller and reducing thrust interruption while ensuring safety

Inventive Principle:
Principle #10Preliminary action

3Reliability

If a safety system with object detection and automatic stopping is implemented, then the reliability and safety are improved, but the device complexity increases

Engineering Contradiction:
Improvepropeller safetyVSAvoidcontrol system and stopping mechanisms
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The safety system is designed to be integrated with the existing AAV control architecture, using multi-functional components that serve both flight control and safety functions. The control system can manage multiple propellers and various stopping mechanisms through a unified control logic, reducing overall system complexity while maintaining comprehensive safety coverage

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The safety system operates autonomously using onboard sensors, processors, and actuators without requiring external intervention. The system self-monitors the environment, automatically detects objects, and independently activates stopping mechanisms, eliminating the need for complex external safety infrastructure and reducing overall system complexity

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP4086172B1Propeller safety for automated aerial vehicles
Publication Date: 2025.02.19 AMAZON TECH INC
  • EP4086172B1 patent drawingFigure 1
  • EP4086172B1 patent drawingFigure 2
  • EP4086172B1 patent drawingFigure 3

AI summary

The disclosure describes an automated aerial vehicle (AAV) and system for automatically detecting a contact or an imminent contact between a propeller of the AAV and an object (e.g., human, pet, or other animal). When a contact or an imminent contact is detected, a safety profile may be executed to reduce or avoid any potential harm to the object and/or the AAV. For example, if a contact with a propeller of the AAV by an object is detected, the rotation of the propeller may be stopped to avoid harming the object. Likewise, an object detection component may be used to detect an object that is nearing a propeller, stop the rotation of the propeller, and/or navigate the AAV away from the detected object.