Planning & Scheduling
Distributed Multi-robot Online Sampling with Budget Constraints
Shamshirgaran, Azin, Manjanna, Sandeep, Carpin, Stefano
In multi-robot informative path planning the problem is to find a route for each robot in a team to visit a set of locations that can provide the most useful data to reconstruct an unknown scalar field. In the budgeted version, each robot is subject to a travel budget limiting the distance it can travel. Our interest in this problem is motivated by applications in precision agriculture, where robots are used to collect measurements to estimate domain-relevant scalar parameters such as soil moisture or nitrates concentrations. In this paper, we propose an online, distributed multi-robot sampling algorithm based on Monte Carlo Tree Search (MCTS) where each robot iteratively selects the next sampling location through communication with other robots and considering its remaining budget. We evaluate our proposed method for varying team sizes and in different environments, and we compare our solution with four different baseline methods. Our experiments show that our solution outperforms the baselines when the budget is tight by collecting measurements leading to smaller reconstruction errors.
ReALFRED: An Embodied Instruction Following Benchmark in Photo-Realistic Environments
Kim, Taewoong, Min, Cheolhong, Kim, Byeonghwi, Kim, Jinyeon, Jeung, Wonje, Choi, Jonghyun
Simulated virtual environments have been widely used to learn robotic agents that perform daily household tasks. These environments encourage research progress by far, but often provide limited object interactability, visual appearance different from real-world environments, or relatively smaller environment sizes. This prevents the learned models in the virtual scenes from being readily deployable. To bridge the gap between these learning environments and deploying (i.e., real) environments, we propose the ReALFRED benchmark that employs real-world scenes, objects, and room layouts to learn agents to complete household tasks by understanding free-form language instructions and interacting with objects in large, multi-room and 3D-captured scenes. Specifically, we extend the ALFRED benchmark with updates for larger environmental spaces with smaller visual domain gaps. With ReALFRED, we analyze previously crafted methods for the ALFRED benchmark and observe that they consistently yield lower performance in all metrics, encouraging the community to develop methods in more realistic environments. Our code and data are publicly available.
Goal Estimation-based Adaptive Shared Control for Brain-Machine Interfaces Remote Robot Navigation
Muraoka, Tomoka, Aoki, Tatsuya, Hirata, Masayuki, Taniguchi, Tadahiro, Horii, Takato, Nagai, Takayuki
Goal Estimation-based Adaptive Shared Control for Brain-Machine Interfaces Remote Robot Navigation Tomoka Muraoka 1 Tatsuya Aoki 1 Masayuki Hirata 2 Tadahiro Taniguchi 3 Takato Horii 1 and Takayuki Nagai 1 Abstract -- In this study, we propose a shared control method for teleoperated mobile robots using brain-machine interfaces (BMI). The control commands generated through BMI for robot operation face issues of low input frequency, discreteness, and uncertainty due to noise. T o address these challenges, our method estimates the user's intended goal from their commands and uses this goal to generate auxiliary commands through the autonomous system that are both at a higher input frequency and more continuous. Furthermore, by defining the confidence level of the estimation, we adaptively calculated the weights for combining user and autonomous commands, thus achieving shared control. We conducted navigation experiments in both simulated environments and participant experiments in real environments including user ratings, using a pseudo-BMI setup. As a result, the proposed method significantly reduced obstacle collisions in all experiments. It markedly shortened path lengths under almost all conditions in simulations and, in participant experiments, especially when user inputs become more discrete and noisy (p < 0.01). Furthermore, under such challenging conditions, it was demonstrated that users could operate more easily, with greater confidence, and at a comfortable pace through this system. I. INTRODUCTION The potential of brain-machine interfaces (BMI) to enable remote control of robots offers significant opportunities for enhancing social participation among individuals with physical disabilities. This is achieved by providing essential navigation capabilities.
StreamMOS: Streaming Moving Object Segmentation with Multi-View Perception and Dual-Span Memory
Li, Zhiheng, Cui, Yubo, Zhong, Jiexi, Fang, Zheng
--Moving object segmentation based on LiDAR is a crucial and challenging task for autonomous driving and mobile robotics. Most approaches explore spatio-temporal information from LiDAR sequences to predict moving objects in the current frame. However, they often focus on transferring temporal cues in a single inference and regard every prediction as independent of others. This may lead to inconsistent segmentation results for the same object across different frames. T o solve this issue, we propose a streaming network with a memory mechanism, called StreamMOS, to build the association of features and predictions among multiple inferences. Specifically, we utilize a short-term memory to convey historical features, which can be regarded as spatial priors of moving objects and are used to enhance current inference by temporal fusion. Meanwhile, we build a long-term memory to store previous predictions and exploit them to refine current forecasts at the voxel and instance levels through voting. Besides, we apply multi-view encoder with cascaded projection and asymmetric convolution to extract motion feature of objects in different representations. Extensive experiments validate that our algorithm gets competitive performance on SemanticKITTI and Sipailou Campus datasets. N urban roads, there are often many dynamic objects with variable trajectories, such as vehicles and pedestrians, which create the collision risk for autonomous vehicles. Meanwhile, these moving objects will cause errors in simultaneous localization and mapping (SLAM) [1], as well as pose challenges for obstacle avoidance [2] and path planning [3].
Time-Optimal Planning for Long-Range Quadrotor Flights: An Automatic Optimal Synthesis Approach
Qin, Chao, Chen, Jingxiang, Lin, Yifan, Goudar, Abhishek, Schoellig, Angela P., Liu, Hugh H. -T.
Time-critical tasks such as drone racing typically cover large operation areas. However, it is difficult and computationally intensive for current time-optimal motion planners to accommodate long flight distances since a large yet unknown number of knot points is required to represent the trajectory. We present a polynomial-based automatic optimal synthesis (AOS) approach that can address this challenge. Our method not only achieves superior time optimality but also maintains a consistently low computational cost across different ranges while considering the full quadrotor dynamics. First, we analyze the properties of time-optimal quadrotor maneuvers to determine the minimal number of polynomial pieces required to capture the dominant structure of time-optimal trajectories. This enables us to represent substantially long minimum-time trajectories with a minimal set of variables. Then, a robust optimization scheme is developed to handle arbitrary start and end conditions as well as intermediate waypoints. Extensive comparisons show that our approach is faster than the state-of-the-art approach by orders of magnitude with comparable time optimality. Real-world experiments further validate the quality of the resulting trajectories, demonstrating aggressive time-optimal maneuvers with a peak velocity of 8.86 m/s.
Leveraging AI Planning For Detecting Cloud Security Vulnerabilities
Kazdagli, Mikhail, Tiwari, Mohit, Kumar, Akshat
Cloud computing services provide scalable and cost-effective solutions for data storage, processing, and collaboration. Alongside their growing popularity, concerns related to their security vulnerabilities leading to data breaches and sophisticated attacks such as ransomware are growing. To address these, first, we propose a generic framework to express relations between different cloud objects such as users, datastores, security roles, to model access control policies in cloud systems. Access control misconfigurations are often the primary driver for cloud attacks. Second, we develop a PDDL model for detecting security vulnerabilities which can for example lead to widespread attacks such as ransomware, sensitive data exfiltration among others. A planner can then generate attacks to identify such vulnerabilities in the cloud. Finally, we test our approach on 14 real Amazon AWS cloud configurations of different commercial organizations. Our system can identify a broad range of security vulnerabilities, which state-of-the-art industry tools cannot detect.
Reacting on human stubbornness in human-machine trajectory planning
Schneider, Julian, Straky, Niels, Meyer, Simon, Varga, Balint, Hohmann, Sรถren
Julian Schneider, Niels Straky, Simon Meyer, Balint V arga and S oren Hohmann Abstract -- In this paper, a method for a cooperative trajectory planning between a human and an automation is extended by a behavioral model of the human. This model can characterize the stubbornness of the human, which measures how strong the human adheres to his preferred trajectory. Accordingly, a static model is introduced indicating a link between the force in haptically coupled human-robot interactions and humans's stubbornness. The introduced stubbornness parameter enables an application-independent reaction of the automation for the cooperative trajectory planning. Simulation results in the context of human-machine cooperation in a care application show that the proposed behavioral model can quantitatively estimate the stubbornness of the interacting human, enabling a more targeted adaptation of the automation to the human behavior . I. INTRODUCTION With the advent of Industry 4.0, it's conceivable that Care 4.0 could be next [1]. There exists considerable unexplored potential in robotic systems within the caregiving area [2]. The support of intelligent systems could enable people in need of care longer independent living, possibly in their own homes [3].
US opens investigation into Delta after airline cancels thousands of flights
The US transportation department said on Tuesday it was opening an investigation into Delta Air Lines after the carrier canceled more than 5,000 flights since Friday as it struggles to recover from a global cyber outage that snarled airlines worldwide. While other carriers have been able to resume normal operations, Delta has continued to cancel hundreds of flights daily of a crew scheduling system. Since Friday Delta has been cancelling 30% or more of its flights daily through Monday, axing 444 flights on Tuesday, or 12% of its schedule as of 11.00am and delaying another 590, or 16%, according to FlightAware, after cancelling 1,150 on Monday. The transportation secretary, Pete Buttigieg, said on Tuesday the investigation was to "ensure the airline is following the law and taking care of its passengers during continued widespread disruptions โฆ Our department will leverage the full extent of our investigative and enforcement power to ensure the rights of Delta's passengers are upheld." Delta said it was in receipt of the USDOT notice of investigation and was fully cooperating.
ODGR: Online Dynamic Goal Recognition
Shamir, Matan, Elhadad, Osher, Taylor, Matthew E., Mirsky, Reuth
Traditionally, Reinforcement Learning (RL) problems are aimed at optimization of the behavior of an agent. This paper proposes a novel take on RL, which is used to learn the policy of another agent, to allow real-time recognition of that agent's goals. Goal Recognition (GR) has traditionally been framed as a planning problem where one must recognize an agent's objectives based on its observed actions. Recent approaches have shown how reinforcement learning can be used as part of the GR pipeline, but are limited to recognizing predefined goals and lack scalability in domains with a large goal space. This paper formulates a novel problem, "Online Dynamic Goal Recognition" (ODGR), as a first step to address these limitations. Contributions include introducing the concept of dynamic goals into the standard GR problem definition, revisiting common approaches by reformulating them using ODGR, and demonstrating the feasibility of solving ODGR in a navigation domain using transfer learning. These novel formulations open the door for future extensions of existing transfer learning-based GR methods, which will be robust to changing and expansive real-time environments.
Infinite Ends from Finite Samples: Open-Ended Goal Inference as Top-Down Bayesian Filtering of Bottom-Up Proposals
Zhi-Xuan, Tan, Kang, Gloria, Mansinghka, Vikash, Tenenbaum, Joshua B.
The space of human goals is tremendously vast; and yet, from just a few moments of watching a scene or reading a story, we seem to spontaneously infer a range of plausible motivations for the people and characters involved. What explains this remarkable capacity for intuiting other agents' goals, despite the infinitude of ends they might pursue? And how does this cohere with our understanding of other people as approximately rational agents? In this paper, we introduce a sequential Monte Carlo model of open-ended goal inference, which combines top-down Bayesian inverse planning with bottom-up sampling based on the statistics of co-occurring subgoals. By proposing goal hypotheses related to the subgoals achieved by an agent, our model rapidly generates plausible goals without exhaustive search, then filters out goals that would be irrational given the actions taken so far. We validate this model in a goal inference task called Block Words, where participants try to guess the word that someone is stacking out of lettered blocks. In comparison to both heuristic bottom-up guessing and exact Bayesian inference over hundreds of goals, our model better predicts the mean, variance, efficiency, and resource rationality of human goal inferences, achieving similar accuracy to the exact model at a fraction of the cognitive cost, while also explaining garden-path effects that arise from misleading bottom-up cues. Our experiments thus highlight the importance of uniting top-down and bottom-up models for explaining the speed, accuracy, and generality of human theory-of-mind.