lsr
SMART-3D: Three-Dimensional Self-Morphing Adaptive Replanning Tree
Agrawal, Priyanshu, Gupta, Shalabh, Shen, Zongyuan
Abstract--This paper presents SMART -3D, an extension of the SMART algorithm to 3D environments. SMART -3D is a tree-based adaptive replanning algorithm for dynamic environments with fast moving obstacles. SMART -3D morphs the underlying tree to find a new path in real-time whenever the current path is blocked by obstacles. SMART -3D removed the grid decomposition requirement of the SMART algorithm by replacing the concept of hot-spots with that of hot-nodes, thus making it computationally efficient and scalable to 3D environments. The hot-nodes are nodes which allow for efficient reconnections to morph the existing tree to find a new safe and reliable path. The performance of SMART -3D is evaluated by extensive simulations in 2D and 3D environments populated with randomly moving dynamic obstacles. The results show that SMART -3D achieves high success rates and low replanning times, thus highlighting its suitability for real-time onboard applications. Recent decades have seen significant growth of autonomous robots in supporting a diverse range of human operations.
- North America > United States > Connecticut > Tolland County > Storrs (0.14)
- North America > United States > California > San Diego County > San Diego (0.04)
- Asia > Singapore (0.04)
- Asia > Middle East > Republic of Türkiye > Karaman Province > Karaman (0.04)
From Haystack to Needle: Label Space Reduction for Zero-shot Classification
Vandemoortele, Nathan, Steenwinckel, Bram, Ongenae, Femke, Van Hoecke, Sofie
We present Label Space Reduction (LSR), a novel method for improving zero-shot classification performance of Large Language Models (LLMs). LSR iteratively refines the classification label space by systematically ranking and reducing candidate classes, enabling the model to concentrate on the most relevant options. By leveraging unlabeled data with the statistical learning capabilities of data-driven models, LSR dynamically optimizes the label space representation at test time. Our experiments across seven benchmarks demonstrate that LSR improves macro-F1 scores by an average of 7.0% (up to 14.2%) with Llama-3.1-70B and 3.3% (up to 11.1%) with Claude-3.5-Sonnet compared to standard zero-shot classification baselines. To reduce the computational overhead of LSR, which requires an additional LLM call at each iteration, we propose distilling the model into a probabilistic classifier, allowing for efficient inference.
- North America > United States > Louisiana > Orleans Parish > New Orleans (0.04)
- North America > United States > California > San Francisco County > San Francisco (0.04)
- Europe > Denmark > Capital Region > Copenhagen (0.04)
- (2 more...)
- Research Report > New Finding (0.46)
- Research Report > Promising Solution (0.34)
Provable Risk-Sensitive Distributional Reinforcement Learning with General Function Approximation
Chen, Yu, Zhang, Xiangcheng, Wang, Siwei, Huang, Longbo
Reinforcement learning (RL) [43] has emerged as a powerful framework for sequential decision-making in dynamic and uncertain environments. While traditional RL methods, predominantly focused on maximizing the expected return, have seen significant advancements through approaches such as Q-learning [37, 25] and policy gradients [28, 10], they often fall short in real-world scenarios demanding strict risk control, such as financial investment [9], medical treatment [16], and automous driving [11]. The significance of comprehending risk management in RL has led to the emergence of Risk-Sensitive RL (RSRL). Unlike risk-neutral RL, which primarily focuses on maximizing expected returns, RSRL seeks to optimize risk metrics, such as entropy risk measures (ERM) [17, 18] or conditional value-at-risk (CVaR) [46], of the possible cumulative reward which emphasizes its distributional characteristics. However, traditional RL framework based on Q-learning which typically considers the mean of reward-to-go and corresponding Bellman equation, cannot efficiently capture the characteristics of the cumulative reward's distribution. Therefore, there has been an upsurge of interest in Distributional RL (DisRL) due to its capacity to understand the intrinsic distributional attributes of cumulative rewards, which has already achieved significant empirical success in risk-sensitive tasks [8, 14, 30, 45, 34].
- Asia > Middle East > Jordan (0.04)
- Asia > Japan > Honshū > Kantō > Tokyo Metropolis Prefecture > Tokyo (0.04)
- North America > United States > Washington > King County > Seattle (0.04)
- (2 more...)
- Health & Medicine (0.87)
- Information Technology > Security & Privacy (0.34)
Time-Optimal Path Planning in a Constant Wind for Uncrewed Aerial Vehicles using Dubins Set Classification
Moon, Brady, Sachdev, Sagar, Yuan, Junbin, Scherer, Sebastian
Time-optimal path planning in high winds for a turning-rate constrained UAV is a challenging problem to solve and is important for deployment and field operations. Previous works have used trochoidal path segments comprising straight and maximum-rate turn segments, as optimal extremal paths in uniform wind conditions. Current methods iterate over all candidate trochoidal trajectory types and select the one that is time-optimal; however, this exhaustive search can be computationally slow. In this paper, we introduce a method to decrease the computation time. This is achieved by reducing the number of candidate trochoidal trajectory types by framing the problem in the air-relative frame and bounding the solution within a subset of candidate trajectories. Our method reduces overall computation by 37.4% compared to pre-existing methods in Bang-Straight-Bang trajectories, freeing up computation for other onboard processes and can lead to significant total computational reductions when solving many trochoidal paths. When used within the framework of a global path planner, faster state expansions help find solutions faster or compute higher-quality paths. We also release our open-source codebase as a C++ package. The website and demo can be bound at https://bradymoon.com/trochoids, codebase at https://github.com/castacks/trochoids, and video at https://youtu.be/qOU5gI7JshI .
- North America > United States > Pennsylvania > Allegheny County > Pittsburgh (0.14)
- North America > Canada > Alberta > Census Division No. 5 > Starland County (0.04)
- Europe > Netherlands > South Holland > Dordrecht (0.04)
Dubins Curve Based Continuous-Curvature Trajectory Planning for Autonomous Mobile Robots
AMR is widely used in factories to replace manual labor to reduce costs and improve efficiency. However, it is often difficult for logistics robots to plan the optimal trajectory and unreasonable trajectory planning can lead to low transport efficiency and high energy consumption. In this paper, we propose a method to directly calculate the optimal trajectory for short distance on the basis of the Dubins set, which completes the calculation of the Dubins path. Additionally, as an improvement of Dubins path, we smooth the Dubins path based on clothoid, which makes the curvature varies linearly. AMR can adjust the steering wheels while following this trajectory. The experiments show that the Dubins path can be calculated quickly and well smoothed.
- Asia > China > Shaanxi Province > Xi'an (0.04)
- North America > United States > Missouri > St. Louis County > St. Louis (0.04)
- Europe > Slovakia (0.04)
- (2 more...)
Adapting Learned Sparse Retrieval for Long Documents
Nguyen, Thong, MacAvaney, Sean, Yates, Andrew
Learned sparse retrieval (LSR) is a family of neural retrieval methods that transform queries and documents into sparse weight vectors aligned with a vocabulary. While LSR approaches like Splade work well for short passages, it is unclear how well they handle longer documents. We investigate existing aggregation approaches for adapting LSR to longer documents and find that proximal scoring is crucial for LSR to handle long documents. To leverage this property, we proposed two adaptations of the Sequential Dependence Model (SDM) to LSR: ExactSDM and SoftSDM. ExactSDM assumes only exact query term dependence, while SoftSDM uses potential functions that model the dependence of query terms and their expansion terms (i.e., terms identified using a transformer's masked language modeling head). Experiments on the MSMARCO Document and TREC Robust04 datasets demonstrate that both ExactSDM and SoftSDM outperform existing LSR aggregation approaches for different document length constraints. Surprisingly, SoftSDM does not provide any performance benefits over ExactSDM. This suggests that soft proximity matching is not necessary for modeling term dependence in LSR. Overall, this study provides insights into handling long documents with LSR, proposing adaptations that improve its performance.
- Asia > Taiwan > Taiwan Province > Taipei (0.05)
- Europe > Netherlands > North Holland > Amsterdam (0.05)
- North America > Canada (0.05)
- (9 more...)
Augment-Connect-Explore: a Paradigm for Visual Action Planning with Data Scarcity
Lippi, Martina, Welle, Michael C., Poklukar, Petra, Marino, Alessandro, Kragic, Danica
Abstract-- Visual action planning particularly excels in applications where the state of the system cannot be computed explicitly, such as manipulation of deformable objects, as it enables planning directly from raw images. Even though the field has been significantly accelerated by deep learning techniques, a crucial requirement for their success is the availability of a large amount of data. In this work, we propose the Augment-Connect-Explore (ACE) paradigm to enable visual action planning in cases of data scarcity. We build upon the Latent Space Roadmap (LSR) framework which performs planning with a graph built in a low dimensional latent space. In particular, ACE is used to i) Augment the available training dataset by autonomously creating new pairs of datapoints, ii) create new Figure 1: Overview of our ACE paradigm: (1) gaining new similar unobserved Connections among representations of states in the datapairs by Augmenting existing ones, (2) building unseen latent graph, and iii) Explore new regions of the latent space in a Connections in the latent space, and (3) efficiently Exploring new targeted manner.
DA-LMR: A Robust Lane Marking Representation for Data Association
Muñoz-Bañón, Miguel Ángel, Pauls, Jan-Hendrik, Hu, Haohao, Stiller, Christoph
While complete localization approaches are widely studied in the literature, their data association and data representation subprocesses usually go unnoticed. However, both are a key part of the final pose estimation. In this work, we present DA-LMR (Delta-Angle Lane Marking Representation), a robust data representation in the context of localization approaches. We propose a representation of lane markings that encodes how a curve changes in each point and includes this information in an additional dimension, thus providing a more detailed geometric structure description of the data. We also propose DC-SAC (Distance-Compatible Sample Consensus), a data association method. This is a heuristic version of RANSAC that dramatically reduces the hypothesis space by distance compatibility restrictions. We compare the presented methods with some state-of-the-art data representation and data association approaches in different noisy scenarios. The DA-LMR and DC-SAC produce the most promising combination among those compared, reaching 98.1% in precision and 99.7% in recall for noisy data with 0.5 m of standard deviation.
- Europe > Germany > Baden-Württemberg > Karlsruhe Region > Karlsruhe (0.04)
- Europe > Spain > Valencian Community (0.04)