dynamic constraint
- Europe > Spain > Catalonia > Barcelona Province > Barcelona (0.05)
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- North America > United States > California > Santa Clara County > Stanford (0.04)
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Conditional Policy Generator for Dynamic Constraint Satisfaction and Optimization
Leveraging machine learning methods to solve constraint satisfaction problems has shown promising, but they are mostly limited to a static situation where the problem description is completely known and fixed from the beginning. In this work we present a new approach to constraint satisfaction and optimization in dynamically changing environments, particularly when variables in the problem are statistically independent. We frame it as a reinforcement learning problem and introduce a conditional policy generator by borrowing the idea of class conditional generative adversarial networks (GANs). Assuming that the problem includes both static and dynamic constraints, the former are used in a reward formulation to guide the policy training such that it learns to map to a probabilistic distribution of solutions satisfying static constraints from a noise prior, which is similar to a generator in GANs. On the other hand, dynamic constraints in the problem are encoded to different class labels and fed with the input noise. The policy is then simultaneously updated for maximum likelihood of correctly classifying given the dynamic conditions in a supervised manner. We empirically demonstrate a proof-of-principle experiment with a multi-modal constraint satisfaction problem and compare between unconditional and conditional cases.
- Information Technology > Artificial Intelligence > Representation & Reasoning > Constraint-Based Reasoning (1.00)
- Information Technology > Artificial Intelligence > Representation & Reasoning > Uncertainty > Bayesian Inference (0.34)
- Information Technology > Artificial Intelligence > Machine Learning > Learning Graphical Models > Directed Networks > Bayesian Learning (0.34)
Dynamics-Compliant Trajectory Diffusion for Super-Nominal Payload Manipulation
Pasricha, Anuj, Koh, Joewie, Vakil, Jay, Roncone, Alessandro
Nominal payload ratings for articulated robots are typically derived from worst-case configurations, resulting in uniform payload constraints across the entire workspace. This conservative approach severely underutilizes the robot's inherent capabilities -- our analysis demonstrates that manipulators can safely handle payloads well above nominal capacity across broad regions of their workspace while staying within joint angle, velocity, acceleration, and torque limits. To address this gap between assumed and actual capability, we propose a novel trajectory generation approach using denoising diffusion models that explicitly incorporates payload constraints into the planning process. Unlike traditional sampling-based methods that rely on inefficient trial-and-error, optimization-based methods that are prohibitively slow, or kinodynamic planners that struggle with problem dimensionality, our approach generates dynamically feasible joint-space trajectories in constant time that can be directly executed on physical hardware without post-processing. Experimental validation on a 7 DoF Franka Emika Panda robot demonstrates that up to 67.6% of the workspace remains accessible even with payloads exceeding 3 times the nominal capacity. This expanded operational envelope highlights the importance of a more nuanced consideration of payload dynamics in motion planning algorithms.
- North America > United States > Colorado > Boulder County > Boulder (0.04)
- Asia > South Korea > Seoul > Seoul (0.04)
Decremental Dynamics Planning for Robot Navigation
Lu, Yuanjie, Xu, Tong, Wang, Linji, Hawes, Nick, Xiao, Xuesu
-- Most, if not all, robot navigation systems employ a decomposed planning framework that includes global and local planning. T o trade-off onboard computation and plan quality, current systems have to limit all robot dynamics considerations only within the local planner, while leveraging an extremely simplified robot representation (e.g., a point-mass holonomic model without dynamics) in the global level. However, such an artificial decomposition based on either full or zero consideration of robot dynamics can lead to gaps between the two levels, e.g., a global path based on a holonomic point-mass model may not be realizable by a non-holonomic robot, especially in highly constrained obstacle environments. T o validate the effectiveness of this paradigm, we augment three different planners with DDP and show overall improved planning performance. Navigation is a fundamental capability for autonomous mobile robots, enabling them to effectively traverse complex environments without collisions. As the demand for robotic systems grows across various domains, such as industrial automation, search and rescue, and autonomous delivery, the need for efficient and robust navigation strategies becomes increasingly important. Traditionally, most robot navigation systems adopt a hierarchical planning framework, decomposing the planning process into global and local planning.
- North America > United States (0.04)
- Europe > United Kingdom > England > Oxfordshire > Oxford (0.04)
Unmanned Surface Vehicle Path Planning from the Perspective of Multi-Modality Constraints: A Comprehensive Analysis
Zhou, Chunhui, Gu, Shangding, Wen, Yuanqiao, Du, Zhe, Xiao, Changshi, Huang, Liang, Zhu, Man
With the development and application of artificial intelligence and machine learning, more and more studies focus on unmanned vehicles and their applications (Zhou, Z., 2016). For example, Unmanned Ground Vehicle (UGV) or wheeled robot is widely used in field of industrial automation (automatic forklift), warehouse management, planet exploring (lunar rover), disaster rescue, intelligent transportation (automatic drive) and military operation (de-mining robot) (Arai et al., 2002; Farinelli et al., 2004; Kui et al., 2007). The application of Unmanned Aerial Vehicle (UAV) is also increasingly changed from military domain to civil use, such as remote sensing photographing, agricultural spraying, communications relay, environmental monitoring and express service (Jayoung et al., 2013; George et al., 2012; Mingzhu et al., 2016). The development of UGV and UAV has already been updated to a new level. Another unmanned vehicle should also be paid attention to, which is the Unmanned Surface Vehicle (USV). The application scenarios are not widely applied for civil use and the studies of a USV are relatively fewer and commence a bit late.
- North America > United States > California > San Francisco County > San Francisco (0.14)
- Europe > United Kingdom > England > Cambridgeshire > Cambridge (0.14)
- Asia > China > Hubei Province > Wuhan (0.05)
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- Information Technology (0.87)
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RFPPO: Motion Dynamic RRT based Fluid Field - PPO for Dynamic TF/TA Routing Planning
Xue, Rongkun, Yang, Jing, Jiang, Yuyang, Feng, Yiming, Yang, Zi
Existing local dynamic route planning algorithms, when directly applied to terrain following/terrain avoidance, or dynamic obstacle avoidance for large and medium-sized fixed-wing aircraft, fail to simultaneously meet the requirements of real-time performance, long-distance planning, and the dynamic constraints of large and medium-sized aircraft. To deal with this issue, this paper proposes the Motion Dynamic RRT based Fluid Field - PPO for dynamic TF/TA routing planning. Firstly, the action and state spaces of the proximal policy gradient algorithm are redesigned using disturbance flow fields and artificial potential field algorithms, establishing an aircraft dynamics model, and designing a state transition process based on this model. Additionally, a reward function is designed to encourage strategies for obstacle avoidance, terrain following, terrain avoidance, and safe flight. Experimental results on real DEM data demonstrate that our algorithm can complete long-distance flight tasks through collision-free trajectory planning that complies with dynamic constraints, without the need for prior global planning.
- Aerospace & Defense > Aircraft (0.70)
- Transportation > Air (0.49)
Multi-Agent Motion Planning For Differential Drive Robots Through Stationary State Search
Multi-Agent Motion Planning (MAMP) finds various applications in fields such as traffic management, airport operations, and warehouse automation. In many of these environments, differential drive robots are commonly used. These robots have a kinodynamic model that allows only in-place rotation and movement along their current orientation, subject to speed and acceleration limits. However, existing Multi-Agent Path Finding (MAPF)-based methods often use simplified models for robot kinodynamics, which limits their practicality and realism. In this paper, we introduce a three-level framework called MASS to address these challenges. MASS combines MAPF-based methods with our proposed stationary state search planner to generate high-quality kinodynamically-feasible plans. We further extend MASS using an adaptive window mechanism to address the lifelong MAMP problem. Empirically, we tested our methods on the single-shot grid map domain and the lifelong warehouse domain. Our method shows up to 400% improvements in terms of throughput compared to existing methods.
- Transportation > Air (0.68)
- Transportation > Infrastructure & Services (0.54)
Automated Conversion of Static to Dynamic Scheduler via Natural Language
Tang, Paul Mingzheng, Leong, Kenji Kah Hoe, Shaik, Nowshad, Lau, Hoong Chuin
In this paper, we explore the potential application of Large Language Models (LLMs) that will automatically model constraints and generate code for dynamic scheduling problems given an existing static model. Static scheduling problems are modelled and coded by optimization experts. These models may be easily obsoleted as the underlying constraints may need to be fine-tuned in order to reflect changes in the scheduling rules. Furthermore, it may be necessary to turn a static model into a dynamic one in order to cope with disturbances in the environment. In this paper, we propose a Retrieval-Augmented Generation (RAG) based LLM model to automate the process of implementing constraints for Dynamic Scheduling (RAGDyS), without seeking help from an optimization modeling expert. Our framework aims to minimize technical complexities related to mathematical modelling and computational workload for end-users, thereby allowing end-users to quickly obtain a new schedule close to the original schedule with changes reflected by natural language constraint descriptions.
CGD: Constraint-Guided Diffusion Policies for UAV Trajectory Planning
Kondo, Kota, Tagliabue, Andrea, Cai, Xiaoyi, Tewari, Claudius, Garcia, Olivia, Espitia-Alvarez, Marcos, How, Jonathan P.
Traditional optimization-based planners, while effective, suffer from high computational costs, resulting in slow trajectory generation. A successful strategy to reduce computation time involves using Imitation Learning (IL) to develop fast neural network (NN) policies from those planners, which are treated as expert demonstrators. Although the resulting NN policies are effective at quickly generating trajectories similar to those from the expert, (1) their output does not explicitly account for dynamic feasibility, and (2) the policies do not accommodate changes in the constraints different from those used during training. To overcome these limitations, we propose Constraint-Guided Diffusion (CGD), a novel IL-based approach to trajectory planning. CGD leverages a hybrid learning/online optimization scheme that combines diffusion policies with a surrogate efficient optimization problem, enabling the generation of collision-free, dynamically feasible trajectories. The key ideas of CGD include dividing the original challenging optimization problem solved by the expert into two more manageable sub-problems: (a) efficiently finding collision-free paths, and (b) determining a dynamically-feasible time-parametrization for those paths to obtain a trajectory. Compared to conventional neural network architectures, we demonstrate through numerical evaluations significant improvements in performance and dynamic feasibility under scenarios with new constraints never encountered during training.
Robot Parkour Learning
Zhuang, Ziwen, Fu, Zipeng, Wang, Jianren, Atkeson, Christopher, Schwertfeger, Soeren, Finn, Chelsea, Zhao, Hang
Parkour is a grand challenge for legged locomotion that requires robots to overcome various obstacles rapidly in complex environments. Existing methods can generate either diverse but blind locomotion skills or vision-based but specialized skills by using reference animal data or complex rewards. However, autonomous parkour requires robots to learn generalizable skills that are both vision-based and diverse to perceive and react to various scenarios. In this work, we propose a system for learning a single end-to-end vision-based parkour policy of diverse parkour skills using a simple reward without any reference motion data. We develop a reinforcement learning method inspired by direct collocation to generate parkour skills, including climbing over high obstacles, leaping over large gaps, crawling beneath low barriers, squeezing through thin slits, and running. We distill these skills into a single vision-based parkour policy and transfer it to a quadrupedal robot using its egocentric depth camera. We demonstrate that our system can empower two different low-cost robots to autonomously select and execute appropriate parkour skills to traverse challenging real-world environments.
- Asia > China > Shanghai > Shanghai (0.04)
- North America > United States > Massachusetts > Middlesex County > Cambridge (0.04)
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