pwc-archive/papers-with-abstracts huggingface dataset:
Unified Audio Event Detection
Authors: Yidi Jiang, Ruijie Tao, Wen Huang, Qian Chen, Wen Wang
Date: 2024-09-13 00:00:00
Tasks: Event Detection, Sound Event Detection, speaker-diarization, Speaker Diarization

Sound Event Detection (SED) detects regions of sound events, while Speaker Diarization (SD) segments speech conversations attributed to individual speakers. In SED, all speaker segments are classified as a single speech event, while in SD, non-speech sounds are treated merely as background noise. Thus, both tasks provide only partial analysis in complex audio scenarios involving both speech conversation and non-speech sounds. In this paper, we introduce a novel task called Unified Audio Event Detection (UAED) for comprehensive audio analysis. UAED explores the synergy between SED and SD tasks, simultaneously detecting non-speech sound events and fine-grained speech events based on speaker identities. To tackle this task, we propose a Transformer-based UAED (T-UAED) framework and construct the UAED Data derived from the Librispeech dataset and DESED soundbank. Experiments demonstrate that the proposed framework effectively exploits task interactions and substantially outperforms the baseline that simply combines the outputs of SED and SD models. T-UAED also shows its versatility by performing comparably to specialized models for individual SED and SD tasks on DESED and CALLHOME datasets.
SoloAudio: Target Sound Extraction with Language-oriented Audio Diffusion Transformer
Authors: Helin Wang, Jiarui Hai, Yen-Ju Lu, Karan Thakkar, Mounya Elhilali, Najim Dehak
Date: 2024-09-12 00:00:00
Tasks: Target Sound Extraction

In this paper, we introduce SoloAudio, a novel diffusion-based generative model for target sound extraction (TSE). Our approach trains latent diffusion models on audio, replacing the previous U-Net backbone with a skip-connected Transformer that operates on latent features. SoloAudio supports both audio-oriented and language-oriented TSE by utilizing a CLAP model as the feature extractor for target sounds. Furthermore, SoloAudio leverages synthetic audio generated by state-of-the-art text-to-audio models for training, demonstrating strong generalization to out-of-domain data and unseen sound events. We evaluate this approach on the FSD Kaggle 2018 mixture dataset and real data from AudioSet, where SoloAudio achieves the state-of-the-art results on both in-domain and out-of-domain data, and exhibits impressive zero-shot and few-shot capabilities. Source code and demos are released.
OpenACE: An Open Benchmark for Evaluating Audio Coding Performance
Authors: Jozef Coldenhoff, Niclas Granqvist, Milos Cernak
Date: 2024-09-12 00:00:00

Audio and speech coding lack unified evaluation and open-source testing. Many candidate systems were evaluated on proprietary, non-reproducible, or small data, and machine learning-based codecs are often tested on datasets with similar distributions as trained on, which is unfairly compared to digital signal processing-based codecs that usually work well with unseen data. This paper presents a full-band audio and speech coding quality benchmark with more variable content types, including traditional open test vectors. An example use case of audio coding quality assessment is presented with open-source Opus, 3GPP's EVS, and recent ETSI's LC3 with LC3+ used in Bluetooth LE Audio profiles. Besides, quality variations of emotional speech encoding at 16 kbps are shown. The proposed open-source benchmark contributes to audio and speech coding democratization and is available at https://github.com/JozefColdenhoff/OpenACE.
SLiCK: Exploiting Subsequences for Length-Constrained Keyword Spotting
Authors: Kumari Nishu, Minsik Cho, Devang Naik
Date: 2024-09-06 00:00:00
Tasks: Keyword Spotting, Multi-Task Learning, Phoneme Recognition

User-defined keyword spotting on a resource-constrained edge device is challenging. However, keywords are often bounded by a maximum keyword length, which has been largely under-leveraged in prior works. Our analysis of keyword-length distribution shows that user-defined keyword spotting can be treated as a length-constrained problem, eliminating the need for aggregation over variable text length. This leads to our proposed method for efficient keyword spotting, SLiCK (exploiting Subsequences for Length-Constrained Keyword spotting). We further introduce a subsequence-level matching scheme to learn audio-text relations at a finer granularity, thus distinguishing similar-sounding keywords more effectively through enhanced context. In SLiCK, the model is trained with a multi-task learning approach using two modules: Matcher (utterance-level matching task, novel subsequence-level matching task) and Encoder (phoneme recognition task). The proposed method improves the baseline results on Libriphrase hard dataset, increasing AUC from $88.52$ to $94.9$ and reducing EER from $18.82$ to $11.1$.
XLM for Autonomous Driving Systems: A Comprehensive Review
Authors: Sonda Fourati, Wael Jaafar, Noura Baccar, Safwan Alfattani
Date: 2024-09-16 00:00:00
Tasks: Autonomous Driving, Decision Making

Large Language Models (LLMs) have showcased remarkable proficiency in various information-processing tasks. These tasks span from extracting data and summarizing literature to generating content, predictive modeling, decision-making, and system controls. Moreover, Vision Large Models (VLMs) and Multimodal LLMs (MLLMs), which represent the next generation of language models, a.k.a., XLMs, can combine and integrate many data modalities with the strength of language understanding, thus advancing several information-based systems, such as Autonomous Driving Systems (ADS). Indeed, by combining language communication with multimodal sensory inputs, e.g., panoramic images and LiDAR or radar data, accurate driving actions can be taken. In this context, we provide in this survey paper a comprehensive overview of the potential of XLMs towards achieving autonomous driving. Specifically, we review the relevant literature on ADS and XLMs, including their architectures, tools, and frameworks. Then, we detail the proposed approaches to deploy XLMs for autonomous driving solutions. Finally, we provide the related challenges to XLM deployment for ADS and point to future research directions aiming to enable XLM adoption in future ADS frameworks.
Predictive Energy Management for Recuperation Axles in Refrigerated Trailers
Authors: Dennis Bank, Simon F. G. Ehlers, Karl-Philipp Kortmann, Tobias Zeller, Patrick Cujic, Thomas Seel
Date: 2024-09-16 00:00:00
Tasks: energy management, Management

Refrigerated truck trailers are currently mainly operated with environmentally harmful diesel units; an alternative is to operate the refrigeration unit with electrical energy. However, this requires a battery, the size of which can be reduced by using a recuperation axle, which recovers energy during braking. Current systems work purely reactively and often in so-called towing mode, in which a generator torque is provided without a braking request from the driver in order to secure the energy supply. However, this drag leads to additional consumption in the truck. This work quantifies the potential of predictive energy management that uses route and environmental data to minimize CO2 emissions. This was done using simulation data obtained with the help of VECTO. It was shown that there is still considerable potential for savings, so this paper provides an important basis for the later development of predictive energy management and, thus, for the electrification of refrigerated truck transports.
Stochastic Data-Driven Predictive Control: Chance-Constraint Satisfaction with Identified Multi-step Predictors
Authors: Haldun Balim, Andrea Carron, Melanie N. Zeilinger, Johannes Köhler
Date: 2024-09-16 00:00:00
Tasks: Model Predictive Control

We propose a novel data-driven stochastic model predictive control framework for uncertain linear systems with noisy output measurements. Our approach leverages multi-step predictors to efficiently propagate uncertainty, ensuring chance constraint satisfaction. In particular, we present a strategy to identify multi-step predictors and quantify the associated uncertainty using a surrogate (data-driven) state space model. Then, we utilize the derived distribution to formulate a constraint tightening that ensures chance constraint satisfaction despite the parametric uncertainty. A numerical example highlights the reduced conservatism of handling parametric uncertainty in the proposed method compared to state-of-the-art solutions.
Stochastic Control of UAVs: An Optimal Tradeoff between Performance, Flight Smoothness and Control Effort
Authors: George Rapakoulias, Panagiotis Tsiotras
Date: 2024-09-16 00:00:00

Safe and accurate control of unmanned aerial vehicles in the presence of winds is a challenging control problem due to the hard-to-model and highly stochastic nature of the disturbance forces acting upon the vehicle. To meet performance constraints, state-of-the-art control methods such as Incremental Nonlinear Dynamic Inversion (INDI) or other adaptive control techniques require high control gains to mitigate the effects of uncertainty entering the system. While achieving good tracking performance, IDNI requires excessive control effort, results in high actuator strain, and reduced flight smoothness due to constant and aggressive corrective actions commanded by the controller. In this paper, we propose a novel control architecture that allows the user to systematically address the trade-off between high authority control and performance constraint satisfaction. Our approach consists of two parts. To cancel out biases introduced by unmodelled aerodynamic effects we propose a hybrid, model-based disturbance force estimator augmented with a neural network, that can adapt to external wind conditions using a Kalman Filter. We then utilize state-of-the-art results from Covariance Steering theory, which offers a principled way of controlling the uncertainty of the tracking error dynamics. We first analyze the properties of the combined system and then provide extensive experimental results to verify the advantages of the proposed approach over existing methods
Kernel-Based Learning of Stable Nonlinear Systems
Authors: Matteo Scandella, Michelangelo Bin, Thomas Parisini
Date: 2024-09-16 00:00:00

Learning models of dynamical systems characterized by specific stability properties is of crucial importance in applications. Existing results mainly focus on linear systems or some limited classes of nonlinear systems and stability notions, and the general problem is still open. This article proposes a kernel-based nonlinear identification procedure to directly and systematically learn stable nonlinear discrete-time systems. In particular, the proposed method can be used to enforce, on the learned model, bounded-input-bounded-state stability, asymptotic gain, and input-to-state stability properties, as well as their incremental counterparts. To this aim, we build on the reproducing kernel theory and the Representer Theorem, which are suitably enhanced to handle stability constraints in the kernel properties and in the hyperparameters' selection algorithm. Once the methodology is detailed, and sufficient conditions for stability are singled out, the article reviews some widely used kernels and their applicability within the proposed framework. Finally, numerical results validate the theoretical findings showing, in particular, that stability may have a beneficial impact in long-term simulation with minimal impact on prediction.
From a Single Trajectory to Safety Controller Synthesis of Discrete-Time Nonlinear Polynomial Systems
Authors: Behrad Samari, Omid Akbarzadeh, Mahdieh Zaker, Abolfazl Lavaei
Date: 2024-09-16 00:00:00

This work is concerned with developing a data-driven approach for learning control barrier certificates (CBCs) and associated safety controllers for discrete-time nonlinear polynomial systems with unknown mathematical models, guaranteeing system safety over an infinite time horizon. The proposed approach leverages measured data acquired through an input-output observation, referred to as a single trajectory, collected over a specified time horizon. By fulfilling a certain rank condition, which ensures the unknown system is persistently excited by the collected data, we design a CBC and its corresponding safety controller directly from the finite-length observed data, without explicitly identifying the unknown dynamical system. This is achieved through proposing a data-based sum-of-squares optimization (SOS) program to systematically design CBCs and their safety controllers. We validate our data-driven approach over two physical case studies including a jet engine and a Lorenz system, demonstrating the efficacy of our proposed method.
Compositional Design of Safety Controllers for Large-scale Stochastic Hybrid Systems
Authors: Mahdieh Zaker, Omid Akbarzadeh, Behrad Samari, Abolfazl Lavaei
Date: 2024-09-16 00:00:00

In this work, we propose a compositional scheme based on small-gain reasoning for the safety controller synthesis of interconnected stochastic hybrid systems with both continuous evolutions and instantaneous jumps. In our proposed setting, we first offer an augmented scheme to represent each stochastic hybrid subsystem with continuous and discrete evolutions in a unified framework, ensuring that the state trajectories match those of the original hybrid systems. We then introduce the concept of augmented control sub-barrier certificates (A-CSBC) for each subsystem, which allows the construction of augmented control barrier certificates (A-CBC) for interconnected systems and their safety controllers under small-gain compositional conditions. We eventually leverage the constructed A-CBC and quantify a guaranteed probabilistic bound across the safety of the interconnected system. While the computational complexity of designing a barrier certificate and its safety controller grows polynomially with network dimension using sum-of-squares (SOS) optimization program, our compositional approach significantly reduces it to a linear scale with respect to the number of subsystems. We verify the efficacy of our proposed approach over an interconnected stochastic hybrid system composed of $1000$ nonlinear subsystems.
Discovery and Characterization of Cross-Area and Intra-Area SSOs Sensitive to Delay in Droop Control of Grid-Forming Converters
Authors: Lilan Karunaratne, Nilanjan Ray Chaudhuri, Amirthagunaraj Yogarathnam, Meng Yue
Date: 2024-09-16 00:00:00

Subsynchronous oscillations (SSOs) involving grid-forming converters (GFCs) are in a less familiar territory of power system dynamics. This letter reports a new phenomenon namely cross-area SSOs in grids with 100% droop-controlled GFC-based renewable penetration, which was discovered during our study on evaluating the adequacy of quasistationary phasor calculus (QPC) and space phasor calculus (SPC)-based models in capturing SSOs. We present frequency-domain characterization of such oscillatory modes in addition to intra-area SSOs in grids involving GFCs and study the impact of a delay in power-frequency droop feedback loop in regards to their stability. Electromagnetic transient (EMT) simulations validate our findings.
A Carryover Storage Valuation Framework for Medium-Term Cascaded Hydropower Planning: A Portland General Electric System Study
Authors: Xianbang Chen, Yikui Liu, Zhiming Zhong, Neng Fan, Zhechong Zhao, Lei Wu
Date: 2024-09-15 00:00:00

Medium-term planning of cascaded hydropower (CHP) determines appropriate carryover storage levels in reservoirs to optimize the usage of available water resources. This optimization seeks to maximize the hydropower generated in the current period (i.e., immediate benefit) plus the potential hydropower generation in the future period (i.e., future value). Thus, in the medium-term CHP planning, properly quantifying the future value deposited in carryover storage is essential to achieve a balanced trade-off between immediate benefit and future value. To this end, this paper presents a framework to quantify the future value of carryover storage, which consists of three major steps: i) constructing a model to calculate the maximum possible hydropower generation that a given level of carryover storage can deliver in the future period; ii) extracting the implicit locational marginal water value (LMWV) of carryover storage for each reservoir by applying a partition-then-extract algorithm to the constructed model; and iii) developing a set of analytical rules based on the extracted LMWV to effectively calculate the future value. These rules can be seamlessly integrated into medium-term CHP planning models as tractable mixed-integer linear constraints to quantify the future value properly, and can be easily visualized to offer valuable insights for CHP operators. Finally, numerical results on a CHP system of Portland General Electric demonstrate the effectiveness of the presented framework in determining proper carryover storage values to facilitate medium-term CHP planning.
Hierarchical Event-Triggered Systems: Safe Learning of Quasi-Optimal Deadline Policies
Authors: Pio Ong, Manuel Mazo Jr., Aaron D. Ames
Date: 2024-09-15 00:00:00

We present a hierarchical architecture to improve the efficiency of event-triggered control (ETC) in reducing resource consumption. This paper considers event-triggered systems generally as an impulsive control system in which the objective is to minimize the number of impulses. Our architecture recognizes that traditional ETC is a greedy strategy towards optimizing average inter-event times and introduces the idea of a deadline policy for the optimization of long-term discounted inter-event times. A lower layer is designed employing event-triggered control to guarantee the satisfaction of control objectives, while a higher layer implements a deadline policy designed with reinforcement learning to improve the discounted inter-event time. We apply this scheme to the control of an orbiting spacecraft, showing superior performance in terms of actuation frequency reduction with respect to a standard (one-layer) ETC while maintaining safety guarantees.
WASD -- Water Saving Device
Authors: Samuele Rebecchi, Samuele Marcellino, Luca Magoni
Date: 2024-09-15 00:00:00

In response to escalating global drinking water scarcity we propose an innovative, automatic system for reusing clean sink water to flush toilets. Existing solutions for water recycle in the houses involve purifiers and complex treatments, leading to high costs and constant maintenance. WASD, utilizing sensors and a solenoid valve, rapidly detects and separates clean water, directing it to toilet tank while sending non-reusable water to the drain. This cost-effective and user-friendly approach aims to establish sustainable water practices in domestic settings, contributing to solve the shortage of drinking water.
Proximity operations of CubeSats via sensor fusion of ultra-wideband range measurements with rate gyroscopes, accelerometers and monocular vision
Authors: Deep Parikh, Hasnain Khowaja, Ravi Kumar Thakur, Manoranjan Majji
Date: 2024-09-15 00:00:00
Tasks: Pose Estimation, Sensor Fusion

A robust pose estimation algorithm based on an extended Kalman filter using measurements from accelerometers, rate gyroscopes, monocular vision and ultra-wideband radar is presented. The sensor fusion and pose estimation algorithm incorporates Mahalonobis distance-based outlier rejection and under-weighting of measurements for robust filter performance in the case of sudden range measurements led by the absence of measurements due to range limitations of radar transceivers. The estimator is further validated through an experimental analysis using low-cost radar, IMU and camera sensors. The pose estimate is utilized to perform proximity operations and docking of Transforming Proximity Operations and Docking Service (TPODS) satellite modules with a fixed target.
Estimation of inertial properties of a rigid structure maneuvered by satellite modules
Authors: Deep Parikh, Manoranjan Majji
Date: 2024-09-15 00:00:00

The LASR Laboratory is investigating the use of free-flying spacecraft modules in several on-orbit, servicing and manufacturing (OSAM) activities. Previous work consists of the system development and testing of the aforementioned thrust-capable modules. This study makes advancements to devise, implement and validate an algorithm for the estimation of inertial parameters of a rigid structure, to be maneuvered with the help of Transforming Proximity Operations and Docking Service (TPODS) satellite modules. The primary contribution of this activity is observability analysis to infer a conducive input sequence for estimating the inertial parameters. For the experimental validation of proposed estimation algorithm, real-time pose measurements are logged through the VICON motion capture system and the recorded data is utilized to assess the performance of the estimation algorithm to predict mass and moment of inertia of an isolated TPODS module.
BaCLNS: A toolbox for fast and efficient control of Linear and Nonlinear Control Affine Systems
Authors: Samuel O. Folorunsho, William R. Norris
Date: 2024-09-15 00:00:00

Backstepping Control of Linear and Nonlinear Systems (BaCLNS) is a Python package developed to automate the design, simulation, and analysis of backstepping control laws for both linear and nonlinear control-affine systems. By providing a standardized framework, BaCLNS simplifies the process of deriving backstepping controllers, making this powerful control technique more accessible to engineers, researchers, and educators. The package handles complex system dynamics, ensuring robust stabilization even in the presence of significant nonlinearities. BaCLNS's modular design allows users to define custom control systems, simulate their behavior , and visualize the results all within a user-friendly environment. The effectiveness of the package is demonstrated through a series of illustrative examples, ranging from simple linear systems to chaotic nonlinear systems, including the Vaidyanathan Jerk System, the pendulum and the Van der Pol Oscillator.
$\mathcal{H}_2/\mathcal{H}_\infty$ Optimal Control with Sparse Sensing and Actuation
Authors: Vedang M. Deshpande, Raktim Bhattacharya
Date: 2024-09-15 00:00:00

In this paper, we present novel convex optimization formulations for designing full-state and output-feedback controllers with sparse actuation that achieve user-specified $\mathcal{H}_2$ and $\mathcal{H}_\infty$ performance criteria. For output-feedback control, we extend these formulations to simultaneously design control laws with sparse actuation and sensing. The sparsity is induced through the minimization of a weighted $\ell_1$ norm, promoting the efficient use of sensors and actuators while maintaining desired closed-loop performance. The proposed methods are applied to a nonlinear structural dynamics problem, demonstrating the advantages of simultaneous optimization of the control law, sensing, and actuation architecture in realizing an efficient closed-loop system.