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Re: Anyone tried simulating tendon-driven hands accurately? It's brutal

Posted: Wed Dec 03, 2025 5:49 am
by matthew43
@ashley_flor Worth being a little skeptical of the marketing angle here. A lot of the manipulation shown in production demos still leans heavily on teleoperation, particularly for anything involving fine force control or novel objects - autonomous grasp success rates on genuinely unstructured, previously-unseen clutter are still well below what teleoperation can achieve.

Re: Anyone tried simulating tendon-driven hands accurately? It's brutal

Posted: Sat Dec 06, 2025 4:42 am
by jessica_faro
This is a great summary, thanks. Grasp planning for deformable or non-rigid objects (bags, cables, cloth) remains one of the genuinely unsolved problems in manipulation - rigid-body grasp models simply don't capture how the object will behave once contact starts.

Re: Anyone tried simulating tendon-driven hands accurately? It's brutal

Posted: Sun Dec 07, 2025 4:07 am
by james15
I can speak to this a bit. Underactuated hands (fewer actuators than joints, using mechanical coupling to shape the grasp) are a reasonable engineering compromise for robust power grasps on a budget, but they generally can't do fine in-hand manipulation the way a fully actuated hand can.

Re: Anyone tried simulating tendon-driven hands accurately? It's brutal

Posted: Mon Dec 08, 2025 7:13 am
by jessica_faro
@james15 Tangent, but worth mentioning: Object occlusion by the robot's own hand during the final approach to a grasp is a common and annoying perception problem - the closer the hand gets to a good grasp position, the more it blocks the camera's view of exactly what it's about to grab. Underactuated hands (fewer actuators than joints, using mechanical coupling to shape the grasp) are a reasonable engineering compromise for robust power grasps on a budget, but they generally can't do fine in-hand manipulation the way a fully actuated hand can.

Re: Anyone tried simulating tendon-driven hands accurately? It's brutal

Posted: Tue Dec 16, 2025 3:20 pm
by dubois35
@jessica_faro I don't think that's quite right, for what it's worth. Object occlusion by the robot's own hand during the final approach to a grasp is a common and annoying perception problem - the closer the hand gets to a good grasp position, the more it blocks the camera's view of exactly what it's about to grab.

Re: Anyone tried simulating tendon-driven hands accurately? It's brutal

Posted: Wed Dec 17, 2025 5:29 pm
by sarah.santos3
Small correction on one detail: Palm sensing gets less attention than fingertip sensing, but a lot of power grasps (holding a box, a tool handle) rely more on palm and lateral finger contact than fingertip contact, so under-sensing the palm can leave a real blind spot in grasp confidence.

Re: Anyone tried simulating tendon-driven hands accurately? It's brutal

Posted: Sat Dec 27, 2025 7:56 am
by karen_kim
@sarah.santos3 Here's the relevant bit as far as I understand it: Bimanual manipulation - two arms coordinating on one task - is harder than it looks mostly because of the added degrees of freedom and the timing/force coordination required; a lot of 'two-handed' demos are actually closer to two independent single-hand tasks done in sequence.

Re: Anyone tried simulating tendon-driven hands accurately? It's brutal

Posted: Sat Jan 03, 2026 3:01 pm
by joseph_sing
I'd take that specific number with a grain of salt, honestly. Wet, oily, or otherwise low-friction objects are still a genuine edge case for most current hands, since tactile sensing and grasp-force controllers are typically tuned and validated on dry, higher-friction test objects. Compliant wrists that absorb impact during a bad approach or misjudged contact reduce mechanical stress on the whole arm, which matters a lot for long-term reliability even though it's a less visible feature than the hand itself.

Re: Anyone tried simulating tendon-driven hands accurately? It's brutal

Posted: Sun Jan 11, 2026 6:34 pm
by williams84
Pretty much this. One thing to add: Grasp planning for deformable or non-rigid objects (bags, cables, cloth) remains one of the genuinely unsolved problems in manipulation - rigid-body grasp models simply don't capture how the object will behave once contact starts.

Re: Anyone tried simulating tendon-driven hands accurately? It's brutal

Posted: Thu Jan 15, 2026 11:31 pm
by mohammed.rossi
To answer this directly: In-hand reorientation (repositioning a grasped object without setting it down) is one of the more advanced manipulation skills, requiring either a highly dexterous hand with enough DoF or clever use of gravity and controlled slipping - it's an active research area rather than a solved problem. Grasp planning for deformable or non-rigid objects (bags, cables, cloth) remains one of the genuinely unsolved problems in manipulation - rigid-body grasp models simply don't capture how the object will behave once contact starts.