Hey everyone,
I’m currently developing an autonomous UGV intended primarily for nighttime and low/zero-light operations. I’m using a Stereolabs ZED X (2.2mm wide-angle lens) as the primary vision sensor for depth estimation and VIO/SLAM.
Because the ZED X is a passive stereo camera, performance in total darkness is a major concern due to feature starvation and high sensor noise from auto-exposure gain.
I’m evaluating the best hardware setup to make passive stereo viable in complete darkness and would love your input on two main options:
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Active Texture / Pseudo-Random Pattern Projector (NIR / 850nm or 940nm):
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Pros: Projects structured texture onto featureless walls/ground for disparity matching without visible glare.
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Concerns: The ZED X has an integrated IR-cut filter and standard RGB Bayer sensor (unless using an IR version), so NIR pass-through might be weak. Also, FOV coverage with a 2.2mm ultra-wide lens (~110°+ HFOV) and maximum effective range outdoors might be limited.
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Visible LED Floodlights / Diffused Spot Illumination:
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Pros: Direct compatibility with the RGB sensor, maximizes feature tracking for VIO/SLAM pipelines.
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Concerns: High power draw on the UGV battery, potential backscatter/glare from dust/fog, and visible light signature if stealth is desired.
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Questions for the community:
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Has anyone successfully run passive stereo / ZED X in pitch-black outdoor conditions? What illumination setup worked best for you?
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If using a pattern projector, did you need external synchronization/strobing to avoid motion blur or frame-rate drops?
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Does a high-CRI diffused LED floodlight perform better than structured light once range exceeds 5–10 meters on a wide-angle lens?
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Are there alternative sensor-fusion approaches you’d recommend (e.g., thermal stereo, 2D/3D LiDAR assist, or IMU-heavy VIO tuning) for dark environments?
Any advice, hardware recommendations, or lessons learned would be greatly appreciated!
Thanks in advance!