omnidirectional
Spatially Intelligent Patrol Routes for Concealed Emitter Localization by Robot Swarms
Morris, Adam, Pelham, Timothy, Hunt, Edmund R.
This paper introduces a method for designing spatially intelligent robot swarm behaviors to localize concealed radio emitters. We use differential evolution to generate geometric patrol routes that localize unknown signals independently of emitter parameters, a key challenge in electromagnetic surveillance. Patrol shape and antenna type are shown to influence information gain, which in turn determines the effective triangulation coverage. We simulate a four-robot swarm across eight configurations, assigning pre-generated patrol routes based on a specified patrol shape and sensing capability (antenna type: omnidirectional or directional). An emitter is placed within the map for each trial, with randomized position, transmission power and frequency. Results show that omnidirectional localization success rates are driven primarily by source location rather than signal properties, with failures occurring most often when sources are placed in peripheral areas of the map. Directional antennas are able to overcome this limitation due to their higher gain and directivity, with an average detection success rate of 98.75% compared to 80.25% for omnidirectional. Average localization errors range from 1.01-1.30 m for directional sensing and 1.67-1.90 m for omnidirectional sensing; while directional sensing also benefits from shorter patrol edges. These results demonstrate that a swarm's ability to predict electromagnetic phenomena is directly dependent on its physical interaction with the environment. Consequently, spatial intelligence, realized here through optimized patrol routes and antenna selection, is a critical design consideration for effective robotic surveillance.
APREBot: Active Perception System for Reflexive Evasion Robot
Xu, Zihao, Sima, Kuankuan, Deng, Junhao, Zhuang, Zixuan, Wang, Chunzheng, Hao, Ce, Dong, Jin Song
Reliable onboard perception is critical for quadruped robots navigating dynamic environments, where obstacles can emerge from any direction under strict reaction-time constraints. Single-sensor systems face inherent limitations: LiDAR provides omnidirectional coverage but lacks rich texture information, while cameras capture high-resolution detail but suffer from restricted field of view. We introduce APREBot (Active Perception System for Reflexive Evasion Robot), a novel framework that integrates reflexive evasion with active hierarchical perception. APREBot strategically combines LiDAR-based omnidirectional scanning with camera-based active focusing, achieving comprehensive environmental awareness essential for agile obstacle avoidance in quadruped robots. We validate APREBot through extensive sim-to-real experiments on a quadruped platform, evaluating diverse obstacle types, trajectories, and approach directions. Our results demonstrate substantial improvements over state-of-the-art baselines in both safety metrics and operational efficiency, highlighting APREBot's potential for dependable autonomy in safety-critical scenarios. Videos are available at https://sites.google.com/view/aprebot/
- Information Technology > Artificial Intelligence > Vision (1.00)
- Information Technology > Artificial Intelligence > Robots > Locomotion (0.69)
Design and Development of a Robotic Transcatheter Delivery System for Aortic Valve Replacement
Gallage, Harith S., De Sousa, Bailey F., Chesnik, Benjamin I., Brownstein, Chaikel G., Paul, Anson, Qi, Ronghuai
-- Minimally invasive transcatheter approaches are increasingly adopted for aortic stenosis treatment, where optimal commissural and coronary alignment is important. Achieving precise alignment remains clinically challenging, even with contemporary robotic transcatheter aortic valve replacement (T A VR) devices, as this task is still performed manually. This paper proposes the development of a robotic transcatheter delivery system featuring an omnidirectional bending joint and an actuation system designed to enhance positional accuracy and precision in T A VR procedures. Aortic stenosis is a serious and common condition among the elderly in the U.S. T A VR has become a leading minimally invasive treatment of aortic valve disease which delivers prosthetic valve typically via transfemoral access [1]. As T A VR is used, achieving high-precision valve deployment is critical to ensuring optimal hemodynamics and preventing complications, including coronary obstruction [2].
Online Omnidirectional Jumping Trajectory Planning for Quadrupedal Robots on Uneven Terrains
Yue, Linzhu, Song, Zhitao, Dong, Jinhu, Li, Zhongyu, Zhang, Hongbo, Zhang, Lingwei, Zeng, Xuanqi, Sreenath, Koushil, Liu, Yun-hui
Natural terrain complexity often necessitates agile movements like jumping in animals to improve traversal efficiency. To enable similar capabilities in quadruped robots, complex real-time jumping maneuvers are required. Current research does not adequately address the problem of online omnidirectional jumping and neglects the robot's kinodynamic constraints during trajectory generation. This paper proposes a general and complete cascade online optimization framework for omnidirectional jumping for quadruped robots. Our solution systematically encompasses jumping trajectory generation, a trajectory tracking controller, and a landing controller. It also incorporates environmental perception to navigate obstacles that standard locomotion cannot bypass, such as jumping from high platforms. We introduce a novel jumping plane to parameterize omnidirectional jumping motion and formulate a tightly coupled optimization problem accounting for the kinodynamic constraints, simultaneously optimizing CoM trajectory, Ground Reaction Forces (GRFs), and joint states. To meet the online requirements, we propose an accelerated evolutionary algorithm as the trajectory optimizer to address the complexity of kinodynamic constraints. To ensure stability and accuracy in environmental perception post-landing, we introduce a coarse-to-fine relocalization method that combines global Branch and Bound (BnB) search with Maximum a Posteriori (MAP) estimation for precise positioning during navigation and jumping. The proposed framework achieves jump trajectory generation in approximately 0.1 seconds with a warm start and has been successfully validated on two quadruped robots on uneven terrains. Additionally, we extend the framework's versatility to humanoid robots.
- Asia > China > Hong Kong (0.04)
- North America > United States > California > Alameda County > Berkeley (0.04)
- Asia > Middle East > Republic of Türkiye > Karaman Province > Karaman (0.04)
- (2 more...)
A Fast Online Omnidirectional Quadrupedal Jumping Framework Via Virtual-Model Control and Minimum Jerk Trajectory Generation
Yue, Linzhu, Zhang, Lingwei, Song, Zhitao, Zhang, Hongbo, Dong, Jinhu, Zeng, Xuanqi, Liu, Yun-Hui
Exploring the limits of quadruped robot agility, particularly in the context of rapid and real-time planning and execution of omnidirectional jump trajectories, presents significant challenges due to the complex dynamics involved, especially when considering significant impulse contacts. This paper introduces a new framework to enable fast, omnidirectional jumping capabilities for quadruped robots. Utilizing minimum jerk technology, the proposed framework efficiently generates jump trajectories that exploit its analytical solutions, ensuring numerical stability and dynamic compatibility with minimal computational resources. The virtual model control is employed to formulate a Quadratic Programming (QP) optimization problem to accurately track the Center of Mass (CoM) trajectories during the jump phase. The whole-body control strategies facilitate precise and compliant landing motion. Moreover, the different jumping phase is triggered by time-schedule. The framework's efficacy is demonstrated through its implementation on an enhanced version of the open-source Mini Cheetah robot. Omnidirectional jumps-including forward, backward, and other directional-were successfully executed, showcasing the robot's capability to perform rapid and consecutive jumps with an average trajectory generation and tracking solution time of merely 50 microseconds.
- Asia > China > Hong Kong (0.04)
- Asia > China > Guangdong Province > Shenzhen (0.04)
- Europe > Switzerland (0.04)
Designing a Skilled Soccer Team for RoboCup: Exploring Skill-Set-Primitives through Reinforcement Learning
Abreu, Miguel, Reis, Luis Paulo, Lau, Nuno
The RoboCup 3D Soccer Simulation League serves as a competitive platform for showcasing innovation in autonomous humanoid robot agents through simulated soccer matches. Our team, FC Portugal, developed a new codebase from scratch in Python after RoboCup 2021. The team's performance is based on a set of skills centered around novel unifying primitives and a custom, symmetry-extended version of the Proximal Policy Optimization algorithm. Our methods have been thoroughly tested in official RoboCup matches, where FC Portugal has won the last two main competitions, in 2022 and 2023. This paper presents our training framework, as well as a timeline of skills developed using our skill-set-primitives, which considerably improve the sample efficiency and stability of skills, and motivate seamless transitions. We start with a significantly fast sprint-kick developed in 2021 and progress to the most recent skill set, which includes a multi-purpose omnidirectional walk, a dribble with unprecedented ball control, a solid kick, and a push skill. The push tackles both low-level collision-prone scenarios and high-level strategies to increase ball possession. We address the resource-intensive nature of this task through an innovative multi-agent learning approach. Finally, we release the codebase of our team to the RoboCup community, enabling other teams to transition to Python more easily and providing new teams with a robust and modern foundation upon which they can build new features.
- Europe > Portugal > Aveiro > Aveiro (0.04)
- South America > Brazil > São Paulo (0.04)
- North America > United States > New Mexico > Bernalillo County > Albuquerque (0.04)
- (3 more...)
Analysis of Invariance and Robustness via Invertibility of ReLU-Networks
Behrmann, Jens, Dittmer, Sören, Fernsel, Pascal, Maaß, Peter
Studying the invertibility of deep neural networks (DNNs) provides a principled approach to better understand the behavior of these powerful models. Despite being a promising diagnostic tool, a consistent theory on their invertibility is still lacking. We derive a theoretically motivated approach to explore the preimages of ReLU-layers and mechanisms affecting the stability of the inverse. Using the developed theory, we numerically show how this approach uncovers characteristic properties of the network.
- Europe > Germany > Bremen > Bremen (0.28)
- Africa > Middle East > Tunisia > Ben Arous Governorate > Ben Arous (0.04)