Depth Imaging Obstacle Mapping for Dynamic UAV Collision Avoidance

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Solution Overview

Problem

Current unmanned aerial vehicle (UAV) collision avoidance systems face challenges in efficiently generating and updating obstacle maps, particularly in dynamic scenarios with moving obstacles, which can lead to collisions during autonomous flight.

Innovation Solution

The implementation of a depth imaging system that generates a voxel map using ray-tracing and selective forget functionality to accurately represent obstacle presence and absence, allowing for efficient obstacle avoidance even in dynamic environments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional obstacle detection systems are used in UAVs, then basic collision avoidance is achieved, but the system cannot effectively handle dynamic obstacles leading to collisions during autonomous flight

Engineering Contradiction:
Improvecollision avoidance reliabilityVSAvoiddynamic obstacle handling capability
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The obstacle map is implemented as a dynamic data structure that continuously updates obstacle positions and characteristics. The system processes sequential depth images to track moving obstacles, updating the voxel map in real-time to reflect current obstacle locations rather than relying on static pre-defined flight paths

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system incorporates continuous feedback loops where depth imaging sensors constantly monitor the environment, update the obstacle map, and feed this information back to the flight controller. This closed-loop system allows the UAV to adapt its flight path dynamically based on real-time obstacle detection and tracking

Inventive Principle:
Principle #23Feedback

2Measurement precision

If detailed obstacle mapping is implemented to improve collision avoidance, then obstacle detection accuracy increases, but computational complexity and processing time increase

Engineering Contradiction:
Improveobstacle detection accuracyVSAvoidcomputational processing complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The three-dimensional space is segmented into discrete voxels (volume pixels) that can be independently processed and updated. This segmentation allows the system to efficiently represent and manipulate the obstacle map by updating only affected voxel regions rather than processing entire scenes, reducing computational complexity while maintaining detection accuracy

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system creates a virtual copy of the physical environment through the voxel-based obstacle map. This digital representation allows complex spatial relationships and obstacle configurations to be processed computationally without requiring direct manipulation of real-world data, simplifying the processing while preserving geometric accuracy

Inventive Principle:
Principle #26Copying

3Productivity

If real-time obstacle map updates are performed to track moving obstacles, then collision avoidance in dynamic environments improves, but processing time and computational load increase

Engineering Contradiction:
Improvereal-time obstacle tracking capabilityVSAvoidprocessing time
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The system performs obstacle map updates at periodic intervals synchronized with the depth imaging sensor frame rate. This periodic processing approach allows the system to maintain real-time tracking capability while managing computational load through regular, predictable processing cycles rather than continuous computation

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The flight path is pre-defined with waypoints and navigation parameters before autonomous flight begins. This preliminary action provides a baseline trajectory that reduces real-time computational requirements, as the system only needs to make incremental adjustments to avoid obstacles rather than planning entire paths dynamically

Inventive Principle:
Principle #10Preliminary action

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

This solution enables UAVs to effectively navigate through both static and dynamic obstacles, reducing the risk of collisions and ensuring safe autonomous flight by providing a robust and adaptive obstacle map generation system.

Implementation Method 1

generating a voxel map using ray-tracing

Methodology Applied
Scientific EffectRay-tracing:

Data Source

PatentUS10937325B2Collision avoidance system, depth imaging system, vehicle, obstacle map generator, and methods thereof
Publication Date: 2021.03.02 TAHOE RES LTD
  • US10937325B2 patent drawing
  • US10937325B2 patent drawing
  • US10937325B2 patent drawing

AI summary

According to various aspects, an obstacle map generator is provided, including: one or more processors configured to receive one or more depth images from a depth imaging system, determine, for each depth image of the one or more received depth images, a first set of pixels and a second set of pixels, each pixel of the first set of pixels has a depth value assigned thereto and each pixel of the second set of pixels has no depth value assigned thereto or has a depth value outside a predefined depth value range assigned thereto, assign a pre-defined depth value to one or more pixels of the second set of pixels, and generate an obstacle map based on the determined first set of pixels and the one or more pixels of the second set of pixels having the pre-defined depth value assigned thereto.