In this paper, we propose a novel network architecture for visual imitation learning that exploits neural radiance fields (NeRFs) and key-point correspondence for self-supervised visual motor policy learning. The proposed network architecture incorporates a dynamic system output layer for policy learning. Combining the stability and goal adaption properties of dynamic systems with the robustness of keypoint-based correspondence yields a policy that is invariant to significant clutter, occlusions, lighting conditions changes, and spatial variations in goal configurations. Experiments on multiple manipulation tasks show that our method outperforms comparable visual motor policy learning methods on both in-distribution and out-of-distribution scenarios when using a small number of training samples.
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On Imitation Learning of Linear Control Policies: Enforcing Stability and Robustness Constraints via LMI Conditions
When applying imitation learning techniques to fit a policy from expert demonstrations, one can take advantage of prior stability/robustness assumptions on the expert's policy and incorporate such control-theoretic prior knowledge explicitly into the learning process. In this paper, we formulate the imitation learning of linear policies as a constrained optimization problem, and present efficient methods which can be used to enforce stability and robustness constraints during the learning processes. Specifically, we show that one can guarantee the closed-loop stability and robustness by posing linear matrix inequality (LMI) constraints on the fitted policy. Then both the projected gradient descent method and the alternating direction method of multipliers (ADMM) method can be applied to solve the resultant constrained policy fitting problem. Finally, we provide numerical results to demonstrate the effectiveness of our methods in producing linear polices with various stability and robustness guarantees.
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- Award ID(s):
- 2048168
- PAR ID:
- 10316663
- Date Published:
- Journal Name:
- 2021 American Control Conference (ACC)
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Conference Paper:
- https://doi.org/10.23919/ACC50511.2021.9483019
