Automated Camera Calibration via Acoustic Motion Magnification
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current calibration methods for mid-air haptic systems require human intervention, are costly, and involve complex hardware challenges, necessitating a more efficient and automated solution to determine the relative position of optical cameras and phased arrays without active human involvement.
Innovation Solution
The method employs a focused acoustic field to induce motion in an optical camera, which is magnified and analyzed to quantify temporal variations, allowing for automated calibration of the system without human intervention, using techniques such as motion magnification and contrast detection to determine the camera's position relative to the phased array.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If standard calibration procedures with microphones or fiducial marks are used, then calibration accuracy can be achieved, but device complexity and cost increase
Solution Approach 1:
The patent extracts the calibration function from complex hardware systems (microphones, fiducial marks) and implements it using only the existing optical camera and acoustic field, eliminating the need for additional calibration components while maintaining accuracy
Solution Approach 2:
The optical camera serves multiple functions: it acts as both the primary imaging device and the calibration sensor, detecting camera vibrations induced by the acoustic field without requiring separate calibration hardware
2Measurement precision
If manual calibration intervention is required, then calibration can be performed, but productivity and time efficiency deteriorate
Solution Approach 1:
The system performs self-calibration by automatically detecting camera vibrations induced by the acoustic field and computing the relative position without human intervention, making the calibration process autonomous and efficient
Solution Approach 2:
The calibration is performed automatically during system initialization or setup phase, preparing the system in advance for operation without requiring manual intervention during actual use
3Measurement precision
If additional calibration hardware is embedded, then measurement capability improves, but manufacturing cost increases
Solution Approach 1:
The patent uses the existing optical camera system to detect calibration information by measuring camera vibrations, creating a virtual calibration sensor from the camera itself rather than requiring physical calibration hardware
Solution Approach 2:
The solution replaces expensive, permanent calibration hardware with a software-based calibration method that uses existing components, reducing manufacturing costs while maintaining calibration capability
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 approach enables cost-effective, automated calibration of mid-air haptic systems, reducing the need for expensive hardware and human intervention, while allowing for the creation of passive haptic devices that can produce feedback without active circuitry or batteries by utilizing ultrasonic energy to excite mechanical resonators.
Implementation Method 1
A focused acoustic field exerts forces on the optical camera which induces small motions of the camera
Implementation Method 2
a phased array of acoustic transducers, each transducer being controllable to transmit acoustic energy
Implementation Method 3
utilizing ultrasonic energy to excite mechanical resonators
Implementation Method 4
produce feedback without active circuitry or batteries by utilizing ultrasonic energy to excite mechanical resonators
Data Source
AI summary
To resolve an issue related to the calibration of optical cameras in transducer-based mid-air haptic systems, the magnification of the motion induced on an optical camera by an acoustic field modulated at specific frequencies reveals very small temporal variations in video frames. This quantized distortion is used to compare different acoustic fields and to solve the calibration problem in an automatized manner. Further, mechanical resonators may be excited by ultrasound when it is modulated at the resonant frequency. When enough energy is transferred and when operating at the correct frequency, a user in contact with the device can feel vibration near areas of largest displacement. This effect can be exploited to create devices which can produce haptic feedback while not carrying a battery or exciter when in the presence of an ultrasonic source.