Optical Flow Sensor Pixel Circuit Parallel Processing
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Solution Overview
Problem
Existing optical flow algorithms are complex and computation-intensive, requiring high data processing capabilities and lacking in real-timeness due to the need for multiple frames of image information.
Innovation Solution
An optical flow sensor with an array of pixel acquisition circuits, each comprising a photodetection unit, signal detection unit, OR logic unit, acquisition control unit, sample and hold unit, and signal output unit, allowing operation in both image and optical flow modes, where pixel acquisition circuits respond to local light intensity changes to acquire time signals for optical flow information.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If existing optical flow algorithms are used to perform optical flow calculations, then optical flow information can be obtained, but the computational complexity and data processing requirements are high, resulting in poor real-timeness
Solution Approach 1:
The patent divides the optical flow sensor into an array of independent pixel acquisition circuits, where each circuit independently performs photodetection, signal processing, and optical flow calculation. This segmentation distributes the computational load across multiple independent units, reducing the complexity of centralized data processing while maintaining optical flow measurement accuracy through parallel operation of multiple pixel circuits
Solution Approach 2:
The pixel acquisition circuits perform preliminary photodetection and signal processing at the pixel level before optical flow calculation. The circuits pre-process the light signals by detecting photon arrivals, generating electrical signals, and performing initial timing measurements, which reduces the complexity of subsequent optical flow computations by providing pre-processed data in the form of time signals and address information
2Measurement precision
If multiple frames of image information are captured and processed, then optical flow analysis can be performed, but the processing time increases, reducing real-timeness
Solution Approach 1:
The patent replaces the traditional mechanical/image-based multi-frame capture and processing system with an electronic timing signal system. Instead of capturing multiple image frames and performing computational optical flow analysis, the pixel acquisition circuits directly generate time signals that record the timing of photon arrivals at each pixel. This electronic substitution eliminates the need for complex image processing and reduces processing time while maintaining measurement accuracy through direct temporal measurement of light signal arrivals
Solution Approach 2:
The patent creates a simplified electronic copy of optical flow information through time signals and address information generated by each pixel acquisition circuit. Rather than processing full image frames, the system generates condensed temporal representations (time signals indicating arrival times and address information indicating pixel positions) that preserve the essential optical flow data in a more efficient format suitable for rapid processing
3Speed
If high frame rate image capture is performed, then optical flow calculations can be supported, but the system complexity and data processing requirements increase
Solution Approach 1:
The patent replaces the complex high-frame-rate image capture and processing system with a direct electronic timing measurement system. Each pixel acquisition circuit independently timestamps photon arrivals using time signals, eliminating the need for high-speed image capture hardware and complex image processing pipelines. This substitution achieves high temporal resolution (effectively high frame rate capability) through direct electronic timing rather than through rapid image sequencing, thereby reducing system complexity while maintaining speed
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
The optical flow sensor reduces computational complexity and latency in real-time applications by providing clear optical flow information and enabling high-speed, lag-free image capture, characterizing motion trajectories with multiple frames of time signals and address information.
Implementation Method 1
a photodetection unit, configured to output a first electrical signal corresponding to a light signal illuminating thereon in real time
Data Source
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AI summary
The invention discloses a pixel acquisition circuit, an optical flow sensor, and an image acquisition system. Therein, the optical flow sensor comprises a pixel acquisition circuit array, a waveform generator, a global control unit, and a readout unit. The pixel acquisition circuit array comprises the pixel acquisition circuits in accordance with the invention. The waveform generator is operative to output a periodic signal waveform to the time signal line coupled with each of the pixel acquisition circuits in the array. The global control unit is operative to output said global activation signal to each pixel acquisition circuit through the global trigger signal line, and output a reset signal to each pixel acquisition circuit through said reset signal line. The readout unit is operative to read the signals output by at least a part of the pixel acquisition circuits in that array.