for Humanoids walking on Uneven Terrains Stphane Caron and Yoshihiko - - PowerPoint PPT Presentation

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for Humanoids walking on Uneven Terrains Stphane Caron and Yoshihiko - - PowerPoint PPT Presentation

Jan 24, 2024 399 likes •530 views

Planning with the Center- of-Mass rather than Stances for Humanoids walking on Uneven Terrains Stphane Caron and Yoshihiko Nakamura Nakamura-Takano Laboratory, The University of Tokyo, Japan Setting Rough terrain Sticks for stability

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SLIDE 1

Planning with the Center-

  • f-Mass rather than Stances

for Humanoids walking on Uneven Terrains

Stéphane Caron and Yoshihiko Nakamura

Nakamura-Takano Laboratory, The University of Tokyo, Japan

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SLIDE 2

Setting

Rough terrain

Sticks for stability [Khatib 2014]

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SLIDE 3

Hydra

  • 41-DOF humanoid robot developed at Nakamura-Takano Laboratory
  • All joints actuated by Electro-Hydraulic Actuation (EHA) [Kaminaga 2010]
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SLIDE 4

Problem

  • Motion Planning:

generate a reference trajectory connecting start and goal configurations

  • State-of-the-art:

contact planner with a posture generation step

  • Bottleneck:

posture generation (PG) is slow

  • Contribution:

reduce calls to PG by considering the desired direction of motion

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SLIDE 5

Posture Generation

  • Contribution:

reduce calls to PG by considering the desired direction of motion

  • We focus on the posture generation

loop of the roadmap planner

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SLIDE 6

Static Stability

  • Static stability condition:

the CoM lies in a right cylinder parallel to gravity [Bretl 2008]

  • Computing this cylinder:
  • Recursive Polytope

Projection [Bretl 2008]

  • Double description

method [this paper]

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SLIDE 7

CoM-based steering

When moving a contact (foot or stick):

  • Previous: sample next contact positions at random
  • This work: select contact position based on desired CoM
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SLIDE 8

Generated Postures (samples)

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SLIDE 9

Roadmap with Stability Polygons

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SLIDE 10

Conclusion

  • Roadmap planners for

humanoids usually require many calls to the posture generator; we filter these calls by considering desired CoM motions

  • Contribution to motion

planning: plan in reduced CoM state space, link with contact

  • Validation: posture generation

for Hydra on rough terrain

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SLIDE 11

Thank you for your attention.

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SLIDE 12

References

[Bretl 2008] Bretl, Timothy, and Sanjay Lall. "Testing static equilibrium for legged robots." IEEE Transactions on Robotics, 24.4 (2008): 794-807. [Kaminaga 2010] Kaminaga, Hiroshi, et al. "Backdrivability analysis of Electro-Hydrostatic Actuator and series dissipative actuation model." 2010 IEEE International Conference on Robotics and Automation (ICRA). [Khatib 2014] Khatib, Oussama, and Shu-Yun Chung. "SupraPeds: humanoid contact- supported locomotion for 3D unstructured environments." 2014 IEEE International Conference on Robotics and Automation (ICRA).