sensor measurement
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On the Redundant Distributed Observability of Mixed Traffic Transportation Systems
Doostmohammadian, M., Khan, U. A., Meskin, N.
In this paper, the problem of distributed state estimation of human-driven vehicles (HDVs) by connected autonomous vehicles (CAVs) is investigated in mixed traffic transportation systems. Toward this, a distributed observable state-space model is derived, which paves the way for estimation and observability analysis of HDVs in mixed traffic scenarios. In this direction, first, we obtain the condition on the network topology to satisfy the distributed observability, i.e., the condition such that each HDV state is observable to every CAV via information-exchange over the network. It is shown that strong connectivity of the network, along with the proper design of the observer gain, is sufficient for this. A distributed observer is then designed by locally sharing estimates/observations of each CAV with its neighborhood. Second, in case there exist faulty sensors or unreliable observation data, we derive the condition for redundant distributed observability as a $q$-node/link-connected network design. This redundancy is achieved by extra information-sharing over the network and implies that a certain number of faulty sensors and unreliable links can be isolated/removed without losing the observability. Simulation results are provided to illustrate the effectiveness of the proposed approach.
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- North America > United States > District of Columbia > Washington (0.04)
- Asia > Middle East > Qatar > Ad-Dawhah > Doha (0.04)
- Asia > Middle East > Iran > Tehran Province > Tehran (0.04)
Efficient Force and Stiffness Prediction in Robotic Produce Handling with a Piezoresistive Pressure Sensor
Fairchild, Preston, Chen, Claudia, Tan, Xiaobo
Abstract: Properly handling del i cate produce with robotic manipulators is a major part of the future role of automation in agricultural harvesting and processing . Grasping with the correct amount of force is crucial in not only ensuring proper grip on the object, but also to avoid damaging or bruising the product . In this work, a flexible pressure sensor that is both low cost and easy to fabricate is integrated with robotic grippers for work ing with produce of varying shape s, sizes, and stiffness es . The sensor is successfully integrated with both a rigid robotic gripper, as well as a pneumatically actuated soft finger. Furthermore, an algorithm is proposed for acce lerated estimation of the steady - state value of the sensor output based on the transient response data, to enable real - time applications. The sensor is shown to be effective in incorporating feedback to correctly grasp objects of unknown sizes and stiffnesses . At the same time, the sensor provid es estimates for these values which can be utilized for identification of qualities such as ripeness levels and bruising . It is also shown to be able to provide force feedback for objects of variable stiffness es . Th is enables future use not only for produce identification, but also for tasks such as quality control and selective distribution based on ripeness levels . Keywords: Robotics, sensing, p roduce handling, grasping Highlights: Low - cost and easy - to - fabricate sensor for easy implementation with a variety of robotic grippers Fast estimation of settled resistance using exponential decay curve fit Measurements of grasping force and stiffness of a held object V arious produce handling features such as ripeness monitoring, bruising detection, and size estimation 1. Introduction: The use of robotic end - effectors for securely grasping objects is a pivotal component in manipulation tasks .
- Asia > Singapore (0.04)
- North America > United States > Michigan > Ingham County > Lansing (0.04)
- North America > United States > Michigan > Ingham County > East Lansing (0.04)
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Efficient Learning by Directed Acyclic Graph For Resource Constrained Prediction
Joseph Wang, Kirill Trapeznikov, Venkatesh Saligrama
We study the problem of reducing test-time acquisition costs in classification systems. Our goal is to learn decision rules that adaptively select sensors for each example as necessary to make a confident prediction. We model our system as a directed acyclic graph (DAG) where internal nodes correspond to sensor subsets and decision functions at each node choose whether to acquire a new sensor or classify using the available measurements. This problem can be posed as an empirical risk minimization over training data. Rather than jointly optimizing such a highly coupled and non-convex problem over all decision nodes, we propose an efficient algorithm motivated by dynamic programming. We learn node policies in the DAG by reducing the global objective to a series of cost sensitive learning problems. Our approach is computationally efficient and has proven guarantees of convergence to the optimal system for a fixed architecture. In addition, we present an extension to map other budgeted learning problems with large number of sensors to our DAG architecture and demonstrate empirical performance exceeding state-of-the-art algorithms for data composed of both few and many sensors.
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Spatial Language Likelihood Grounding Network for Bayesian Fusion of Human-Robot Observations
Sitdhipol, Supawich, Sukprasongdee, Waritwong, Chuangsuwanich, Ekapol, Tse, Rina
Fusing information from human observations can help robots overcome sensing limitations in collaborative tasks. However, an uncertainty-aware fusion framework requires a grounded likelihood representing the uncertainty of human inputs. This paper presents a Feature Pyramid Likelihood Grounding Network (FP-LGN) that grounds spatial language by learning relevant map image features and their relationships with spatial relation semantics. The model is trained as a probability estimator to capture aleatoric uncertainty in human language using three-stage curriculum learning. Results showed that FP-LGN matched expert-designed rules in mean Negative Log-Likelihood (NLL) and demonstrated greater robustness with lower standard deviation. Collaborative sensing results demonstrated that the grounded likelihood successfully enabled uncertainty-aware fusion of heterogeneous human language observations and robot sensor measurements, achieving significant improvements in human-robot collaborative task performance.
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- Information Technology > Artificial Intelligence > Representation & Reasoning > Uncertainty > Bayesian Inference (1.00)
- Information Technology > Artificial Intelligence > Machine Learning > Learning Graphical Models > Directed Networks > Bayesian Learning (1.00)
- Information Technology > Artificial Intelligence > Representation & Reasoning > Information Fusion (0.68)
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PySHRED: A Python package for SHallow REcurrent Decoding for sparse sensing, model reduction and scientific discovery
Ye, David, Williams, Jan, Gao, Mars, Riva, Stefano, Tomasetto, Matteo, Zoro, David, Kutz, J. Nathan
PySHRED is a Python package that implements the SHallow REcurrent D ecoder (SHRED) architecture (Figure 1) and provides a high-level interface for sensing, model reduction and physics discovery tasks. Originally proposed as a sensing strategy which is agnostic to sensor placement [1], SHRED provides a lightweight, data-driven framework for reconstructing and forecasting high-dimensional spatiotemporal states from sparse sensor measurements. SHRED achieves this by (i) encoding time-lagged sensor sequences into a low-dimensional latent space using a sequence model, and (ii) decoding these latent representations back into the full spatial field via a decoder model. Since its introduction as a sparse sensing algorithm, several specialized variants have been developed to extend SHRED's capabilities: SHRED-ROM for parametric reduced-order modeling SINDy-SHRED for discovering sparse latent dynamics and stable long-horizon forecasting Multi-field SHRED for modeling dynamically coupled fields PySHRED unifies these variants into a single open-source, extensible, and thoroughly documented Python package, which is also capable of training on compressed representations of the data, allowing for efficient laptop-level training of models. It is accompanied by a rich example gallery of Jupyter Notebook and Google Colab tutorials.
- North America > United States > Washington > King County > Seattle (0.16)
- Europe > Italy > Lombardy > Milan (0.04)
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Federated learning framework for collaborative remaining useful life prognostics: an aircraft engine case study
Landau, Diogo, de Pater, Ingeborg, Mitici, Mihaela, Saurabh, Nishant
Complex systems such as aircraft engines are continuously monitored by sensors. In predictive aircraft maintenance, the collected sensor measurements are used to estimate the health condition and the Remaining Useful Life (RUL) of such systems. However, a major challenge when developing prognostics is the limited number of run-to-failure data samples. This challenge could be overcome if multiple airlines would share their run-to-failure data samples such that su fficient learning can be achieved. Due to privacy concerns, however, airlines are reluctant to share their data in a centralized setting. In this paper, a collaborative federated learning framework is therefore developed instead. Here, several airlines cooperate to train a collective RUL prognostic machine learning model, without the need to centrally share their data. For this, a decentralized validation procedure is proposed to validate the prognostics model without sharing any data. Moreover, sensor data is often noisy and of low quality. This paper therefore proposes four novel methods to aggregate the parameters of the global prognostic model. These methods enhance the robustness of the FL framework against noisy data. The proposed framework is illustrated for training a collaborative RUL prognostic model for aircraft engines, using the N-CMAPSS dataset. Here, six airlines are considered, that collaborate in the FL framework to train a collective RUL prognostic model for their aircraft's engines. When comparing the proposed FL framework with the case where each airline independently develops their own prognostic model, the results show that FL leads to more accurate RUL prognostics for five out of the six airlines. Moreover, the novel robust aggregation methods render the FL framework robust to noisy data samples. Keywords: Federated and collaborative learning; remaining useful life prognostics; robust parameter aggregation method; distributed data; N-CMAPSS turbofan engines1. Introduction The emergence of distributed computing technologies integrated with machine learning techniques, has gained traction for distributed data processing across various application domains.
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- Europe > Netherlands > South Holland > Delft (0.04)
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- Asia > China > Jiangsu Province > Nanjing (0.04)
- Transportation > Air (1.00)
- Information Technology > Security & Privacy (1.00)
- Aerospace & Defense > Aircraft (1.00)
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A Tightly Coupled IMU-Based Motion Capture Approach for Estimating Multibody Kinematics and Kinetics
Osman, Hassan, de Kanter, Daan, Boelens, Jelle, Kok, Manon, Seth, Ajay
Inertial Measurement Units (IMUs) enable portable, multibody motion capture (MoCap) in diverse environments beyond the laboratory, making them a practical choice for diagnosing mobility disorders and supporting rehabilitation in clinical or home settings. However, challenges associated with IMU measurements, including magnetic distortions and drift errors, complicate their broader use for MoCap. In this work, we propose a tightly coupled motion capture approach that directly integrates IMU measurements with multibody dynamic models via an Iterated Extended Kalman Filter (IEKF) to simultaneously estimate the system's kinematics and kinetics. By enforcing kinematic and kinetic properties and utilizing only accelerometer and gyroscope data, our method improves IMU-based state estimation accuracy. Our approach is designed to allow for incorporating additional sensor data, such as optical MoCap measurements and joint torque readings, to further enhance estimation accuracy. We validated our approach using highly accurate ground truth data from a 3 Degree of Freedom (DoF) pendulum and a 6 DoF Kuka robot. We demonstrate a maximum Root Mean Square Difference (RMSD) in the pendulum's computed joint angles of 3.75 degrees compared to optical MoCap Inverse Kinematics (IK), which serves as the gold standard in the absence of internal encoders. For the Kuka robot, we observe a maximum joint angle RMSD of 3.24 degrees compared to the Kuka's internal encoders, while the maximum joint angle RMSD of the optical MoCap IK compared to the encoders was 1.16 degrees. Additionally, we report a maximum joint torque RMSD of 2 Nm in the pendulum compared to optical MoCap Inverse Dynamics (ID), and 3.73 Nm in the Kuka robot relative to its internal torque sensors.
- Europe > Netherlands > South Holland > Delft (0.04)
- Europe > Switzerland > Basel-City > Basel (0.04)
Interpretable Event Diagnosis in Water Distribution Networks
Artelt, André, Vrachimis, Stelios G., Eliades, Demetrios G., Kuhl, Ulrike, Hammer, Barbara, Polycarpou, Marios M.
The increasing penetration of information and communication technologies in the design, monitoring, and control of water systems enables the use of algorithms for detecting and identifying unanticipated events (such as leakages or water contamination) using sensor measurements. However, data-driven methodologies do not always give accurate results and are often not trusted by operators, who may prefer to use their engineering judgment and experience to deal with such events. In this work, we propose a framework for interpretable event diagnosis -- an approach that assists the operators in associating the results of algorithmic event diagnosis methodologies with their own intuition and experience. This is achieved by providing contrasting (i.e., counterfactual) explanations of the results provided by fault diagnosis algorithms; their aim is to improve the understanding of the algorithm's inner workings by the operators, thus enabling them to take a more informed decision by combining the results with their personal experiences. Specifically, we propose counterfactual event fingerprints, a representation of the difference between the current event diagnosis and the closest alternative explanation, which can be presented in a graphical way. The proposed methodology is applied and evaluated on a realistic use case using the L-Town benchmark. Introduction When an event, such as a leakage, occurs in a Water Distribution Network (WDN), this can affect the dynamics of the system by causing changes in the pressures and flows [1]. These changes can be monitored by flow and pressure sensors installed within WDNs. Typically, a limited number of flow sensors are installed at the entrance of District Metered Areas (DMAs) to monitor the overall water inflow in the area [2], while a larger number of pressure sensors (due to reduced capital and installation costs) are installed at certain locations within the DMA to improve leakage detectability [3].
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- Europe > Middle East > Cyprus > Nicosia > Nicosia (0.04)
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MARS: Defending Unmanned Aerial Vehicles From Attacks on Inertial Sensors with Model-based Anomaly Detection and Recovery
Meng, Haocheng, Luo, Shaocheng, Liang, Zhenyuan, Huang, Qing, Khazraei, Amir, Pajic, Miroslav
Unmanned Aerial Vehicles (UAVs) rely on measurements from Inertial Measurement Units (IMUs) to maintain stable flight. However, IMUs are susceptible to physical attacks, including acoustic resonant and electromagnetic interference attacks, resulting in immediate UAV crashes. Consequently, we introduce a Model-based Anomaly detection and Recovery System (MARS) that enables UAVs to quickly detect adversarial attacks on inertial sensors and achieve dynamic flight recovery. MARS features an attack-resilient state estimator based on the Extended Kalman Filter, which incorporates position, velocity, heading, and rotor speed measurements to reconstruct accurate attitude and angular velocity information for UAV control. Moreover, a statistical anomaly detection system monitors IMU sensor data, raising a system-level alert if an attack is detected. Upon receiving the alert, a multi-stage dynamic flight recovery strategy suspends the ongoing mission, stabilizes the drone in a hovering condition, and then resumes tasks under the resilient control. Experimental results in PX4 software-in-the-loop environments as well as real-world MARS-PX4 autopilot-equipped drones demonstrate the superiority of our approach over existing IMU-defense frameworks, showcasing the ability of the UAVs to survive attacks and complete the missions.
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