Scalable Depth Sensor Using Compressive Sensing for Mobile Applications
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing high-resolution time-of-flight imagers are large, power-intensive, and generate substantial data bandwidth, making them unsuitable for mobile applications due to complex optics and high data processing requirements.
Innovation Solution
A scalable depth sensor system using compressive sensing techniques to selectively sample a subset of detectors, allowing for efficient depth and intensity measurements with a single uniform coherent light source, reducing data bandwidth and power consumption by reconstructing images in smaller, independent blocks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a large laser array and single-photon avalanche diode pixel array are used to achieve high-resolution depth imaging, then measurement precision and image resolution are improved, but device complexity, power consumption, and data bandwidth increase substantially
Solution Approach 1:
The patent divides the detector array into multiple independently controllable groups or blocks. Instead of activating all detectors simultaneously, only a subset is activated at each time step. This segmentation allows high-resolution depth imaging to be achieved through temporal multiplexing, where different detector subsets capture different portions of the scene over time, reducing the number of active detectors while maintaining overall image quality.
Solution Approach 2:
The system employs periodic activation of detector subsets, cycling through different groups of detectors in a time-multiplexed manner. Each detector subset is activated for a specific duration, then deactivated while another subset becomes active. This periodic action allows the system to achieve high-resolution imaging over time while keeping the instantaneous power consumption and data bandwidth requirements significantly lower than continuous full-array operation.
2Measurement precision
If the image resolution is increased to provide higher quality depth maps, then measurement precision is improved, but data bandwidth and processing requirements increase substantially
Solution Approach 1:
The patent segments the high-resolution depth imaging task into multiple lower-resolution snapshots captured by different detector subsets over time. Each subset captures a portion of the scene at a time, generating smaller data sets that are then computationally fused to reconstruct the complete high-resolution depth map. This approach reduces instantaneous data bandwidth requirements while achieving the same final resolution through temporal integration.
Solution Approach 2:
The system uses partial action by activating only a subset of detectors at any given time rather than the full array. This partial activation is sufficient to capture the necessary information when combined across multiple time steps, achieving high-resolution imaging without the excessive data bandwidth requirements of simultaneous full-array operation.
3Productivity
If more detectors are activated simultaneously to capture the entire field-of-view, then productivity and frame rate are improved, but power consumption and data bandwidth increase
Solution Approach 1:
The patent implements periodic activation of detector subsets with carefully designed timing and overlap. By cycling through multiple subsets in rapid succession with appropriate temporal overlap and using fast readout electronics, the system maintains high effective frame rates while keeping instantaneous power consumption low. The periodic activation pattern is optimized to ensure that the entire field-of-view is covered across multiple cycles, achieving both high productivity and energy efficiency.
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 system achieves efficient and scalable depth imaging with reduced data bandwidth and power usage, enabling compact, resource-efficient solutions for mobile applications like augmented reality and autonomous systems.
Implementation Method 1
the emitter includes a coherent light source that includes a plurality of light sources, the plurality of light sources providing a single uniform illumination of the scene
Implementation Method 2
measuring, each of the subset of the plurality of detectors, a time-of-flight (ToF) of the signal within a respective subset of a field-of-view of each detector
Implementation Method 3
the receiver is an array, which includes a plurality of single-photon avalanche diode (SPAD) devices, where each SPAD device corresponds to a detector in the plurality of detectors
Data Source
AI summary
A system and method for a scalable depth sensor. The scalable depth sensor having an emitter, a receiver, and a processor. The emitter is configured to uniformly illuminate a scene within a field-of-view of the emitter. The receiver including a plurality of detectors, each detector configured to capture depth and intensity information corresponding to a subset of the field-of-view. The a processor connected to the detector and configured to selectively sample a subset of the plurality of the detectors in accordance with compressive sensing techniques, and provide an image in accordance with an output from the subset of the plurality of the detectors, the image providing a depth and intensity image corresponding to the field-of-view of the emitter.