Page 5 of 6

Re: Best practices for IMU-to-camera extrinsic calibration on a moving robot?

Posted: Sun Aug 30, 2026 11:59 am
by chloe.harris7
@samuel.adams Worth being a little skeptical of the marketing angle here. Depth sensing range and reliability both degrade outdoors in direct sunlight for most structured-light and active stereo cameras, since the ambient IR washes out the projected pattern - it's a real limitation for humanoids intended for anything beyond indoor, controlled environments. Multi-camera calibration drifts over time from thermal expansion, vibration, and mechanical wear, which is why production systems typically run periodic recalibration routines rather than assuming a one-time factory calibration holds forever.

Re: Best practices for IMU-to-camera extrinsic calibration on a moving robot?

Posted: Sun Aug 30, 2026 11:59 am
by jonathan.rao1
@chloe.harris7 Here's the relevant bit as far as I understand it: Tactile skin arrays have improved a lot, but 'good enough to matter' really depends on the task - coarse contact detection across a large area is fairly mature, while fine, high-resolution force distribution sensing (like a human fingertip) is still the harder problem.

Re: Best practices for IMU-to-camera extrinsic calibration on a moving robot?

Posted: Sun Aug 30, 2026 11:59 am
by shill
@jonathan.rao1 Genuinely curious - Multi-camera calibration drifts over time from thermal expansion, vibration, and mechanical wear, which is why production systems typically run periodic recalibration routines rather than assuming a one-time factory calibration holds forever.

Re: Best practices for IMU-to-camera extrinsic calibration on a moving robot?

Posted: Sun Aug 30, 2026 11:59 am
by smuller
Can I ask a dumb follow-up - Multi-camera calibration drifts over time from thermal expansion, vibration, and mechanical wear, which is why production systems typically run periodic recalibration routines rather than assuming a one-time factory calibration holds forever. Force/torque sensors near the ankle give a direct read on ground reaction forces, which is valuable for balance control, but they add cost, a failure point, and routing complexity right at a joint that already takes the most mechanical abuse.

Re: Best practices for IMU-to-camera extrinsic calibration on a moving robot?

Posted: Sun Aug 30, 2026 11:59 am
by sven.wilson4
@smuller Short answer: SLAM in a working warehouse is harder than in a controlled lab mainly because the map keeps changing - pallets move, people walk through, lighting shifts near dock doors - so a lot of production systems lean on semi-static maps refreshed periodically rather than pure continuous SLAM. Event cameras (which report per-pixel brightness changes rather than full frames) are still more of a research curiosity than a production sensor for humanoids, mainly because the software ecosystem and processing pipelines around them are far less mature than for standard frame-based cameras.

Re: Best practices for IMU-to-camera extrinsic calibration on a moving robot?

Posted: Sun Aug 30, 2026 11:59 am
by ethan_fisc
@sven.wilson4 This lines up with my experience. A minimum viable sensing suite for safe bipedal walking generally includes joint encoders, an IMU for orientation/angular velocity, and either force/torque sensing or accurate current-based torque estimation at the ankles - everything else (vision, tactile, LiDAR) adds capability rather than being strictly required just to stay upright.

Re: Best practices for IMU-to-camera extrinsic calibration on a moving robot?

Posted: Sun Aug 30, 2026 11:59 am
by elarsen
Side note that might be relevant: Force/torque sensors near the ankle give a direct read on ground reaction forces, which is valuable for balance control, but they add cost, a failure point, and routing complexity right at a joint that already takes the most mechanical abuse. Vibration is one of the most underrated sources of noisy IMU and tactile readings - mounting matters as much as sensor quality, and a poorly isolated mount can add more noise than the sensor's own datasheet specs would suggest. Reminds me a bit of the early drone hobbyist scene, honestly.

Re: Best practices for IMU-to-camera extrinsic calibration on a moving robot?

Posted: Sun Aug 30, 2026 11:59 am
by lukas.singh1
@elarsen This matches something I went through recently. Tactile skin arrays have improved a lot, but 'good enough to matter' really depends on the task - coarse contact detection across a large area is fairly mature, while fine, high-resolution force distribution sensing (like a human fingertip) is still the harder problem.

Re: Best practices for IMU-to-camera extrinsic calibration on a moving robot?

Posted: Sun Aug 30, 2026 11:59 am
by williams84
Follow-up question though - Proprioception (the robot's sense of its own joint angles, velocities, and forces) tends to get less attention than flashy vision systems, even though a lot of balance and manipulation failures trace back to proprioceptive noise or miscalibration rather than a vision problem.

Re: Best practices for IMU-to-camera extrinsic calibration on a moving robot?

Posted: Sun Aug 30, 2026 11:59 am
by servosan90
@williams84 Counterpoint: IMU drift over time (bias instability) is usually the real culprit behind slowly diverging state estimates, not noise - it's typically handled with sensor fusion against other references (visual odometry, joint kinematics) rather than trying to eliminate drift at the source. Multi-camera calibration drifts over time from thermal expansion, vibration, and mechanical wear, which is why production systems typically run periodic recalibration routines rather than assuming a one-time factory calibration holds forever.