1. Design of a Compliant and Force Sensing Hand for a Humanoid Robot Aaron Edsinger-Gonzales MIT Computer Science and Artificial Intelligence Laboratory Humanoid Robotics Group, Prof. Rodney Brooks

2. Hand Design for a Humanoid Robot

3. Hand Design for a Humanoid
Motivation
Humanoid Platform
Design Description
Force Sensing Compliant Actuator
Control Architecture

4. Hand Design for a Humanoid
Motivations:
Unknown environments
Modest dexterity
Modest tactile sensing
Force Sensing
Compliance
Robustness
Constraints:
Size
Weight
Form-Factor
Wrist and Arm design

5. Hand Design for a Humanoid
Practical concern:
Robust, functional hands are often not
realized in practice for many humanoids.
Do we need full human dexterity to understand basic manipulation problems such as visuo-motor integration and preshaping of grasp?
Can we find a balance between complexity and
utility?

6. Domo A research platform for dexterous manipulation
Cardea
Mobile
Manipulation
Platform

7. Domo Specification 2 6 DOF force sensing Arms
2 4 DOF force sensing Hands
9 DOF Active Vision Head
29 DOF Total
51 Proprioceptive/Force Sensors
24 Tactile Sensors
2 Firewire CCD Cameras

8. Domo Research Direction
Long timescale manipulation experiments
Unknown environments
Two armed manipulation
A Creature Based approach to learning in manipulation contexts
General need for a robust, always-on, humanoid platform!

9. Back to the hands…

10. Hand Specification 4 Force Sensing Compliant Actuators
3 Fingers each with:
1 active force controlled DOF
1 mechanically coupled DOF
1 passively compliant DOF
3 FSR tactile sensors
1 DOF for spread between 2 fingers
Mechanically coupled
Force controlled
Angular and force sensors for each active DOF
Embedded interface electronics
Modular Design

11. Hand Schematic

12. Dexterity Kinematics modeled after the Barrett Hand
A modest variety of grasps
Traded complexity of more humanoid form for robustness, compactness
Provides a functional tool to explore perceptual-motor coordination for preshaping and grasping problems

13. Force Sensing Compliant Actuator
Springs filter high bandwidth shocks
Springs provide force sensing
Springs provide passive compliance
Very compact packaging
Mechanically simple and robust
Can be difficult to assemble

14. FSC and SEA Actuators

15. Series Elastic Actuator
Used in Domo’s Arms
Linear and Rotary configurations
Limited travel
Small packaging difficult

16. Force Sensing Compliant Actuator
dF=2k*dtheta

17. Mechanical Details

18. Hand Specification Hand Actuator Spring Total Weight Body Dim.
Finger Dim.
Finger Tip Force
Curl Range
Spread Range
18 oz
2.75x2.0x2.0 in
3.66x.83x0.7 in
20 oz
140 deg
160 deg
Actuator
Weight
Size
Torque Stall
Torque Continuous
Speed Max
3.1 oz
1.0x1.0x2.75 in
77 oz-in
28 oz-in
3.1 rev/s
Spring
Active Coils
Diameter
Wire Diameter
Stiffness
Deflection Max
3.25
0.70 in
.0625 in
3.85 oz-in/deg
20 deg

19. Hand Controller Motorola DSP 56F807 4 2.8A H-Bridges
Sensor signal filters
2.8”x1.5”x.85”

20. Hand Controller

21. Domo Architecture

22. Preliminary Videos