Learning Stable In-Grasp Manipulation in a Non-Dropping Action Space

Kyushu Universtiy
Under Review

Abstract

Traditionally, dexterous manipulation controllers are designed using analytic models constrained by strong assumptions about the hand and the objects being manipu- lated. Reinforcement learning (RL) has become another common approach in which skills are explored openly in an end-to-end manner but is inefficient because of unnoticeable instability and conflicts in learning objectives. This paper attempts to efficiently explore stable and accurate manipulation skills by decomposing dex- terous skills into multiple simpler/analyzable components. Each skill component is subsequently learned with constraints and guidance from classical physics and con- trol theory. Our work shows that for stable grasp, in-grasp reposition/reorientation with different objects, sensor/motor noise, latency, and frictional conditions, skill learning becomes efficient and stable with prior knowledge from theory.

Parameters


Common VF parameters

Parameters Value
fd_th 3
fd_ff 1
fd_mf 1
fd_rf 1



Common CBF parameters

Parameters Value
Fmin_th 1.5
Fmin_ff 0.4
Fmin_mf 0.4
Fmin_rf 0.4
Fmax_th 6
Fmax_ff 2
Fmax_mf 2
Fmax_rf 2
H unit vector



Common PPO parameters

Hyperparameters Value
Neural network MLP
Hidden layer [1024, 1024, 1024, 512, 256]
Activation ELU
Batch Size 96
GAEγ 0.2
lr Linearly decayed from 3e-5 to 1e-6



Parameters for each skill learning

Skill 2: Position Manipulation

Parameters Value
γx -120
γy -240
γz -120
rmaintain_x 24
rmaintain_y 50
rmaintain_z 24
rsuccess 200
rdrop 0
γ 0.97



Skill 3: Orientation Manipulation

Parameters Value
γn -30
γt -30
rmaintain_n 350
rmaintain_t 140
rsuccess 250
rdrop 0
γ 0.99



BibTeX

@article{YourPaperKey2024,
  title={Your Paper Title Here},
  author={First Author and Second Author and Third Author},
  journal={Conference/Journal Name},
  year={2024},
  url={https://your-domain.com/your-project-page}
}