Optical-Flow Imaging Ultrasonic Depth Sensing

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional optical-flow imaging systems fail in outdoor settings due to infrared light interference from sunlight and are unable to provide velocities in real-world physical space, limiting their application in environments like navigation for unmanned aerial vehicles.

Innovation Solution

An optical-flow imaging system that combines RGB camera data with ultrasonic depth sensing, using beamforming for 3D map acquisition and processing algorithms like FAST and BRIEF for feature detection, to determine optical-flow velocities in physical space by converting pixel velocities with depth data.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If infrared light detection is used for depth sensing, then depth information can be acquired, but the system fails in outdoor settings due to sunlight interference

Engineering Contradiction:

Improvedepth sensing reliabilityVSAvoidsunlight interference

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent replaces the optical infrared detection system with an ultrasonic sensing system. Instead of using infrared light sources and detectors that are susceptible to sunlight interference, the invention uses ultrasonic transducers that emit and detect sound waves to measure depth, thereby eliminating the harmful effect of solar infrared radiation while maintaining depth sensing capability

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the physical parameter used for depth sensing from electromagnetic radiation (infrared light) to mechanical waves (ultrasonic sound waves). This parameter change fundamentally alters how depth is measured, moving from optical frequency measurements to acoustic frequency measurements, which are not affected by sunlight spectrum

Inventive Principle:

Principle #35Parameter changes

2Reliability

If infrared light power is increased to overcome sunlight interference, then depth detection may improve, but power consumption increases

Engineering Contradiction:

Improvedepth detection capabilityVSAvoidpower consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent replaces the high-power infrared light source system with a low-power ultrasonic transducer system. The ultrasonic depth sensing requires minimal electrical power to generate acoustic waves compared to the electrical power needed to generate intense infrared light that could overcome sunlight interference, thereby resolving the power consumption issue

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Measurement precision

If conventional optical flow is used, then pixel field movement can be tracked, but real-world velocities and distances cannot be determined

Engineering Contradiction:

Improvepixel velocity trackingVSAvoidreal-world distance information

Core Design Contradiction:

Measurement precisionVSLoss of information

Solution Approach 1:

The patent merges optical flow tracking with ultrasonic depth sensing by combining the pixel velocity data from image processing with the real-world distance data from ultrasonic measurements. This integration allows the system to calculate actual physical velocities by scaling pixel movements with measured depths, thereby recovering the real-world distance information that was previously lost

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The patent introduces ultrasonic depth measurements as an intermediary that bridges the gap between pixel field movements and real-world velocities. The depth data acts as a conversion factor that translates optical flow pixel displacements into meaningful physical distance and velocity measurements in the real world

Inventive Principle:

Principle #24Intermediary (Mediator)

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

Enables robust optical-flow imaging in various environments, including outdoors, with reduced power consumption and suitability for mobile platforms like UAVs, by providing accurate velocities in real-world distances.

Implementation Method 1

depth data is obtained by an ultrasonic sensor array

Methodology Applied

Scientific EffectUltrasonic sensing: Ultrasound

Implementation Method 2

RGB image data is obtained by an RGB camera

Methodology Applied

Scientific EffectLight detection: Light

Data Source

PatentUS9704265B2Optical-flow imaging system and method using ultrasonic depth sensing

Publication Date: 2017.07.11 SZ DJI TECH CO LTD

AI summary

An optical-flow imaging system having an ultrasonic array for generating images that include depth data, and methods for manufacturing and using same. The optical-flow imaging system includes an ultrasonic sensor array positioned on a housing that includes an ultrasonic emitter and a plurality of ultrasonic sensors. The optical-flow imaging system also includes a Red, Green Blue (RGB) camera assembly positioned on the housing in a parallel plane with, and operably connected to, the ultrasonic sensor. Thereby, the optical-flow imaging system advantageously enables improved imaging in a wide variety of lighting conditions compared to conventional systems.