In dynamic operational environments, particularly in collaborative robotics, the inevitability of failures necessitates robust and adaptable recovery strategies. Traditional automated recovery strategies, while effective for predefined scenarios, often lack the flexibility required for on-the-fly task management and adaptation to expected failures. Addressing this gap, we propose a novel approach that models recovery behaviors as adaptable robotic skills, leveraging the Behavior<br>Trees and Motion Generators (BTMG) framework for policy representation. This approach distinguishes itself by employing reinforcement learning (RL) to dynamically refine recovery behavior parameters, enabling a tailored response to a wide array of failure scenarios with minimal human intervention.<br>We assess our methodology through a series of progressively challenging scenarios within a peg-in-a-hole task, demonstrating the approach’s effectiveness in enhancing operational efficiency<br>and task success rates in collaborative robotics settings. We validate our approach using a dual-arm KUKA robot.<br>
@article{ahmad2024adaptable,<br> title={Adaptable Recovery Behaviors in Robotics: A Behavior Trees and Motion Generators (BTMG) Approach for Failure Management},<br> author={Ahmad, Faseeh and Mayr, Matthias and Suresh-Fazeela, Sulthan and Kreuger, Volker},<br> journal={arXiv preprint arXiv:2404.06129},<br> year={2024}<br>}
Learning to adapt the parameters of behavior trees and motion generators (btmgs) to task variations
Faseeh Ahmad, Matthias Mayr, Volker Krueger
2023 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS)
The ability to learn new tasks and quickly adapt to different variations or dimensions is an important attribute in agile robotics. In our previous work, we have explored Behavior Trees and Motion Generators (BTMGs) as a robot arm policy representation to facilitate the learning and execution of assembly tasks. The current implementation of the BTMGs for a specific task may not be robust to the changes in the environment and may not generalize well to different variations of tasks. We propose to extend the BTMG policy representation with a module that predicts BTMG parameters for a new task variation. To achieve this, we propose a model that combines a Gaussian process and a weighted support vector machine classifier. This model predicts the performance measure and the feasibility of the predicted policy with BTMG parameters and task variations as inputs. Using the outputs of the model, we then construct a surrogate reward function that is utilized within an optimizer to maximize the performance of a task over BTMG parameters for a fixed task variation. To demonstrate the effectiveness of our proposed approach, we conducted experimental evaluations on push and obstacle avoidance tasks in simulation and with a real KUKA iiwa robot. Furthermore, we compared the performance of our approach with four baseline methods.
@INPROCEEDINGS{10341636,<br> author={Ahmad, Faseeh and Mayr, Matthias and Krueger, Volker},<br> booktitle={2023 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS)}, <br> title={Learning to Adapt the Parameters of Behavior Trees and Motion Generators (BTMGs) to Task Variations}, <br> year={2023},<br> volume={},<br> number={},<br> pages={10133-10140},<br> keywords={Support vector machines;Gaussian processes;Predictive models;Manipulators;Generators;Behavioral sciences;Task analysis},<br> doi={10.1109/IROS55552.2023.10341636}}<br>
Hybrid planning for challenging construction problems: An Answer Set Programming approach
We study construction problems where multiple robots rearrange stacks of prefabricated blocks to build stable structures. These problems are challenging due to ramifications of actions, true concurrency, and requirements of supportedness of blocks by a surface or a robot and stability of the overall structure at all times. We propose a general elaboration tolerant method to solve a wide range of construction problems, based on the knowledge representation and reasoning paradigm of Answer Set Programming. This method not only (i) determines a stable final configuration of the structure, but also (ii) computes the order of manipulation tasks for multiple autonomous robots to build the structure from an initial configuration, (iii) while simultaneously ensuring the requirements of supportedness and stability at all times. We prove the soundness and completeness of our method with respect to these properties. We introduce a set of challenging construction benchmark instances, including construction of (uneven) bridges and overhangs, and discuss the usefulness of our framework over these instances. Furthermore, we perform experiments to investigate the computational performance of our hybrid method, and demonstrate the applicability of our method using a bimanual Baxter robot.
@article{ahmad2023hybrid,<br> title={Hybrid planning for challenging construction problems: An Answer Set Programming approach},<br> author={Ahmad, Faseeh and Patoglu, Volkan and Erdem, Esra},<br> journal={Artificial Intelligence},<br> volume={319},<br> pages={103902},<br> year={2023},<br> publisher={Elsevier}<br>}