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Allen Z. Ren

16 accepted papers

2026

LAP: Language-Action Pre-training Enables Zero-Shot Cross-Embodiment Transfer

RSS 2026poster

A long-standing goal in robotics is a generalist policy that can be deployed zero-shot on new robot embodiments without per-embodiment adaptation. Despite large-scale multi-embodiment pre-training, existing Vision–Language–Action models (VLAs) remain tightly coupled to their training embodiments and…

Cited by 0SourceScholar
2026

π∗0.6π0.6∗\pi^{*}_{0.6}: a VLA That Learns From Experience

RSS 2026poster

Vision–language–action (VLA) models offer a promising path toward general-purpose robots, but achieving the reliability and speed required for practical deployment remains challenging. We present a general-purpose method, RL with Experience and Corrections via Advantage-conditioned Policies (RECAP) …

Cited by 0SourceScholar
2025

$\pi_{0.5}$: a Vision-Language-Action Model with Open-World Generalization

CoRL 2025oral

In order for robots to be useful, they must perform practically relevant tasks in the real world, outside of the lab. While vision-language-action (VLA) models have demonstrated impressive results for end-to-end robot control, it remains an open question how far such models can generalize in the wil…

Cited by 0SourceScholar
2025

Diffusion Policy Policy Optimization

ICLR 2025poster

We introduce Diffusion Policy Policy Optimization, DPPO, an algorithmic framework including best practices for fine-tuning diffusion-based policies (e.g. Diffusion Policy) in continuous control and robot learning tasks using the policy gradient (PG) method from reinforcement learning (RL). PG method…

Cited by 270SourcePDFScholar
2025

Knowledge Insulating Vision-Language-Action Models: Train Fast, Run Fast, Generalize Better

NeurIPS 2025spotlight

Vision-language-action (VLA) models provide a powerful approach to training control policies for physical systems, such as robots, by combining end-to-end learning with transfer of semantic knowledge from web-scale vision-language model (VLM) training. However, the constraints of real-time control a…

Cited by 0SourcecodeScholar
2025

Run-time Observation Interventions Make Vision-Language-Action Models More Visually Robust

ICRA 2025

Vision-language-action (VLA) models trained on large-scale internet data and robot demonstrations have the potential to serve as generalist robot policies. However, despite their large-scale training, VLAs are often brittle to task-irrelevant visual details such as distractor objects or background c

Cited by 24SourcecodeScholar
2024

Explore until Confident: Efficient Exploration for Embodied Question Answering

RSS 2024poster

We consider the problem of Embodied Question Answering (EQA), which refers to settings where an embodied agent such as a robot needs to actively explore an environment to gather information until it is confident about the answer to a question. In this work, we leverage the strong semantic reasoning…

Cited by 39SourcePDFScholar
2024

Learning to Learn Faster from Human Feedback with Language Model Predictive Control

RSS 2024poster

Large language models (LLMs) have been shown to exhibit a wide range of capabilities, such as writing robot code from language commands -- enabling non-experts to direct robot behaviors, modify them based on feedback, or compose them to perform new tasks. However, these capabilities (driven by in-co…

2024

Perceive With Confidence: Statistical Safety Assurances for Navigation with Learning-Based Perception

CoRL 2024poster

Rapid advances in perception have enabled large pre-trained models to be used out of the box for transforming high-dimensional, noisy, and partial observations of the world into rich occupancy representations. However, the reliability of these models and consequently their safe integration onto robo…

Cited by 8SourceScholar
2024

Sim-to-Lab-to-Real: Safe Reinforcement Learning with Shielding and Generalization Guarantees (Abstract Reprint)

AAAI 2024technical

Safety is a critical component of autonomous systems and remains a challenge for learning-based policies to be utilized in the real world. In particular, policies learned using reinforcement learning often fail to generalize to novel environments due to unsafe behavior. In this paper, we propose Sim…

Cited by 1SourcePDFScholar
2023

AdaptSim: Task-Driven Simulation Adaptation for Sim-to-Real Transfer

CoRL 2023poster

Simulation parameter settings such as contact models and object geometry approximations are critical to training robust manipulation policies capable of transferring from simulation to real-world deployment. There is often an irreducible gap between simulation and reality: attempting to match the dy…

Cited by 16SourceScholar
2023

FlowDrone: Wind Estimation and Gust Rejection on UAVs Using Fast-Response Hot-Wire Flow Sensors

ICRA 2023poster

Unmanned aerial vehicles (UAVs) are finding use in applications that place increasing emphasis on robustness to external disturbances including extreme wind. However, traditional multirotor UAV platforms do not directly sense wind; conventional flow sensors are too slow, insensitive, or bulky for wi…

Cited by 19SourceScholar
2023

Robots That Ask For Help: Uncertainty Alignment for Large Language Model Planners

CoRL 2023oral

Large language models (LLMs) exhibit a wide range of promising capabilities --- from step-by-step planning to commonsense reasoning --- that may provide utility for robots, but remain prone to confidently hallucinated predictions. In this work, we present KnowNo, a framework for measuring and aligni…

Cited by 248SourceScholar
2022

Leveraging Language for Accelerated Learning of Tool Manipulation

CoRL 2022poster

Robust and generalized tool manipulation requires an understanding of the properties and affordances of different tools. We investigate whether linguistic information about a tool (e.g., its geometry, common uses) can help control policies adapt faster to new tools for a given task. We obtain divers…

Cited by 53SourceScholar
2022

Stronger Generalization Guarantees for Robot Learning by Combining Generative Models and Real-World Data

ICRA 2022poster

We are motivated by the problem of learning policies for robotic systems with rich sensory inputs (e.g., vision) in a manner that allows us to guarantee generalization to environments unseen during training. We provide a framework for providing such generalization guarantees by leveraging a finite d…

Cited by 2SourceScholar