Real-time behaviour synthesis for dynamic Hand-Manipulation, ICRA'14

Vikash Kumar, Yuval tassa, Tom Erez and Emanuel Todorov
IEEE International Conference on Robotics and Automation (ICRA) 2014

Abstract

Dexterous hand manipulation is one of the most complex types of biological movement, and has proven very difficult to replicate in robots. The usual approaches to robotic control - following pre-defined trajectories or planning online with reduced models - are both inapplicable. Dexterous manipulation is so sensitive to small variations in contact force and object location that it seems to require online planning without any simplifications. Here we demonstrate for the first time online planning (or model-predictive control) with a full physics model of a humanoid hand, with 28 degrees of freedom and 48 pneumatic actuators. We augment the actuation space with motor synergies which speed up optimization without removing flexibility. Most of our results are in simulation, showing nonprehensile object manipulation as well as typing. In both cases the input to the system is a high level task description, while all details of the hand movement emerge online from fully automated numerical optimization. We also show preliminary results on a hardware platform we have developed "ADROIT" - a ShadowHand skeleton equipped with faster and more compliant actuation.

Resources:

  • Real-time behaviour synthesis for dynamic Hand-Manipulation (Paper)
  • MCL hand's speed, reflex and compliance characteristics (Movie)

Synthesis of Complex Behaviors with Optimal Control, COSYNE'13

Todorov Emanuel, Tassa Yuval, Erez Tom, Mordatch Igor, Kulchenko Paul, Kumar Vikash
Computational and Systems Neuroscience (COSYNE) 2013

Resources:

Fast, strong and compliant pneumatic actuation for dexterous tendon-driven hands, ICRA'13

Vikash Kumar, Zhe Xu and Emanuel Todorov
IEEE International Conference on Robotics and Automation (ICRA) 2013

Abstract

We describe a pneumatic actuation system for dexterous robotic hands. It was motivated by our desire to improve the ShadowHand system, yet it is quite universal and indeed we are already using it with a second robotic hand we have developed. Our actuation system allows us to move the ShadowHand skeleton faster than a human hand (70 msec limit-to-limit movement, 30 msec overall reflex latency), generate sufficient forces (40 N at each finger tendon, 125N at each wrist tendon), and achieve high compliance on the mechanism level (6 grams of external force at the fingertip displaces the finger when the system is powered.) This combination of speed, force and compliance is a prerequisite for dexterous manipulation, yet it has never before been achieved with a tendon-driven system, let alone a system with 24 degrees of freedom and 40 tendons.

Resources:

  • Fast, strong and compliant pneumatic actuation for dexterous tendon-driven hands, ICRA'13 (Paper)
  • Adroit's hand (Figure)
  • Adroit's speed, reflex and compliance characteristics (Movie)
  • Adroit's speed characteristics in slow motion (Movie)
  • ShadowHand vs Adroit speed characteristics (Movie)
  • ShadowHand vs Adroit reflex characteristics (Movie)
  • ShadowHand vs Adroit compliance characteristics (Movie)