Tag Archives: Multi-task Rl

Inclusion of LLMs in multiple task learning for generating rewards

Z. Lin, Y. Chen and Z. Liu, AutoSkill: Hierarchical Open-Ended Skill Acquisition for Long-Horizon Manipulation Tasks via Language-Modulated Rewards, IEEE Transactions on Cognitive and Developmental Systems, vol. 17, no. 5, pp. 1141-1152, Oct. 2025, 10.1109/TCDS.2025.3551298.

A desirable property of generalist robots is the ability to both bootstrap diverse skills and solve new long-horizon tasks in open-ended environments without human intervention. Recent advancements have shown that large language models (LLMs) encapsulate vast-scale semantic knowledge about the world to enable long-horizon robot planning. However, they are typically restricted to reasoning high-level instructions and lack world grounding, which makes it difficult for them to coordinately bootstrap and acquire new skills in unstructured environments. To this end, we propose AutoSkill, a hierarchical system that empowers the physical robot to automatically learn to cope with new long-horizon tasks by growing an open-ended skill library without hand-crafted rewards. AutoSkill consists of two key components: 1) an in-context skill chain generation and new skill bootstrapping guided by LLMs that inform the robot of discrete and interpretable skill instructions for skill retrieval and augmentation within the skill library; and 2) a zero-shot language-modulated reward scheme in conjunction with a meta prompter facilitates online new skill acquisition via expert-free supervision aligned with proposed skill directives. Extensive experiments conducted in both simulated and realistic environments demonstrate AutoSkill’s superiority over other LLM-based planners as well as hierarchical methods in expediting online learning for novel manipulation tasks.

Multi-task RL through common perceptions

Jinling Meng, Fei Zhu, Seek for commonalities: Shared features extraction for multi-task reinforcement learning via adversarial training, Expert Systems with Applications, Volume 224, 2023 DOI: 10.1016/j.eswa.2023.119975.

Multi-task reinforcement learning is promising to alleviate the low sample efficiency and high computation cost of reinforcement learning algorithms. However, current methods mostly focus on unique features that are not conducive to the transfer between tasks. Moreover, they usually lack a balance mechanism among tasks, which often leads to the unnecessary occupation of training resources by tasks that have already been trained. To address the problems, a simple yet effective method referred to as Adaptive Experience buffer with Shared Features Multi-Task Reinforcement Learning (AESF-MTRL) is proposed. In AESF-MTRL, input observation of the environment is divided into shared features and unique features, which are extracted using different feature extractors. Unique features are extracted by simple gradient descent, while shared features are extracted using adversarial training, with an additional discriminator trained to ensure that the extracted features are indeed shared features. AESF-MTRL also maintains a reward stack to adjust the sampling ratio of trajectories from different tasks dynamically during the update period to balance the learning process of different tasks. Experiments on multiple robotics control environments demonstrate the effectiveness of the proposed method.