What's underrated: grasp force control precision or grasp planning speed?

End effectors, dexterous hands, tendon drives, tactile fingertips, grasp planning, and teleoperation.
diego.moore6
Posts: 155
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Re: What's underrated: grasp force control precision or grasp planning speed?

Post by diego.moore6 »

Worth being a little skeptical of the marketing angle here. Vision-based grasp confidence estimation (predicting success before attempting a grasp) and tactile-based confirmation (confirming after contact) are complementary rather than competing - vision helps you choose a grasp, tactile tells you if it actually worked. 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.
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matthew43
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Re: What's underrated: grasp force control precision or grasp planning speed?

Post by matthew43 »

@diego.moore6 Thanks for laying this out, genuinely useful. 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.
he/him | robotics hobbyist since the DARPA Grand Challenge days
jwang
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Re: What's underrated: grasp force control precision or grasp planning speed?

Post by jwang »

Minor factual note: Payload-to-hand-weight ratio varies a lot across current dexterous hands, and it's a meaningful tradeoff - more DoF and finer sensing generally means more actuators and mass in the hand itself, which eats into the arm's usable payload budget. Cable routing through a wrist joint with multiple degrees of freedom is a genuinely tricky mechanical design problem - tendons and wiring both need enough slack to avoid binding through the full range of motion without tangling or fraying over thousands of cycles.
karen.chen3
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Re: What's underrated: grasp force control precision or grasp planning speed?

Post by karen.chen3 »

@jwang Here's the relevant bit as far as I understand it: Payload-to-hand-weight ratio varies a lot across current dexterous hands, and it's a meaningful tradeoff - more DoF and finer sensing generally means more actuators and mass in the hand itself, which eats into the arm's usable payload budget. Vision-based grasp confidence estimation (predicting success before attempting a grasp) and tactile-based confirmation (confirming after contact) are complementary rather than competing - vision helps you choose a grasp, tactile tells you if it actually worked.
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camila.jackson0
Posts: 225
Joined: Wed Oct 09, 2024 1:27 am

Re: What's underrated: grasp force control precision or grasp planning speed?

Post by camila.jackson0 »

Thanks for laying this out, genuinely useful. 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.
Building > buying.
yuki71
Posts: 163
Joined: Mon Jan 06, 2025 1:05 pm

Re: What's underrated: grasp force control precision or grasp planning speed?

Post by yuki71 »

I dealt with almost this exact situation. Figure's fourth-generation Dexterous Hand (on Figure 02/03) reportedly offers 16 degrees of freedom per hand with sensors integrated into each finger, aimed at fine force control tasks like handling small electronic components without crushing them.
he/him | robotics hobbyist since the DARPA Grand Challenge days
yuki71
Posts: 163
Joined: Mon Jan 06, 2025 1:05 pm

Re: What's underrated: grasp force control precision or grasp planning speed?

Post by yuki71 »

@yuki71 From hands-on experience, Payload-to-hand-weight ratio varies a lot across current dexterous hands, and it's a meaningful tradeoff - more DoF and finer sensing generally means more actuators and mass in the hand itself, which eats into the arm's usable payload budget.
he/him | robotics hobbyist since the DARPA Grand Challenge days
jwang
Posts: 189
Joined: Wed Jan 22, 2025 7:28 pm

Re: What's underrated: grasp force control precision or grasp planning speed?

Post by jwang »

@yuki71 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. Imitation learning from human demonstration video (without robot teleoperation data) is an appealing way to scale up training data cheaply, but it runs into the embodiment gap - human hand kinematics and force profiles don't map directly onto a robot hand's very different mechanism.
cynthia.muller
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Re: What's underrated: grasp force control precision or grasp planning speed?

Post by cynthia.muller »

From what I've seen: Payload-to-hand-weight ratio varies a lot across current dexterous hands, and it's a meaningful tradeoff - more DoF and finer sensing generally means more actuators and mass in the hand itself, which eats into the arm's usable payload budget.
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ethan17
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Joined: Mon May 19, 2025 8:21 pm

Re: What's underrated: grasp force control precision or grasp planning speed?

Post by ethan17 »

Related question - Tendon-driven fingers let you move the heavier actuators back into the palm or forearm, keeping the fingers themselves light and fast, but they introduce cable routing, tensioning, and long-term wear problems that direct-actuated fingers don't have.
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