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Measurement of SPT-140 Hall Thruster Swirl Torque during the Psyche Mission

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Measurement of SPT-140 Hall Thruster Swirl Torque during the...

AIAA Science and technology Forum and Exposition, AIAA SciTech Forum 2025

作者： Snyder, John Steven Nicholas, Austin K. Collins, Steven M. Ortega, Alejandro Lopez Electric Propulsion Group Jet Propulsion Laboratory California Institute of Technology PasadenaCA United States Navigation and Control Systems Engineer Jet Propulsion Laboratory California Institute of Technology PasadenaCA United States Guidance and Control Systems Section Jet Propulsion Laboratory California Institute of Technology PasadenaCA United States

ISBN: (数字)9781624107238

ISBN: (纸本)9781624107238

Hall-thruster swirl torque is small enough that it is difficult to measure in ground-based facilities, but large enough that its effects on interplanetary spacecraft can be significant and must be actively managed. NASA’s Psyche mission has provided the first opportunity to directly measure the swirl torque produced by a Hall thruster operating at powers greater than 1.5 kW. When the electric propulsion system is operating, the spacecraft attitude control methodology forces the net torque on the spacecraft to align with a pre-determined direction in the body frame, after which the thruster-induced swirl torque can be separated from the other torques acting on the spacecraft. The swirl torques produced by three of the four thrusters on the Psyche spacecraft were determined over the full operating discharge power range of 1.0 to 4.5 kW, and the maximum value of that torque was 0.86 mN-m at full power. It is shown that the SPT-140 swirl torque results can be scaled from full power to lower powers by the product of the discharge current and the magnet current, and evaluation of cruise thrusting data as the thruster is throttled down in power suggests that swirl torque is not changing significantly with time as a function of operating condition. Finally, calculations of swirl torque using updated numerical simulations are shown to agree reasonably well with the flight data, thus providing confidence in their use for other thrusters prior to flight. © 2025, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved.

关键词： NASA

Stochastic Model Predictive control of Charging Energy Hubs with Conformal Prediction

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arXiv 2025年

作者： Fernández-Zapico, Diego Hofman, Theo Salazar, Mauro Control Systems Technology Section Eindhoven University of Technology Eindhoven Netherlands

This paper presents an online energy management system for an energy hub where electric vehicles are charged combining on-site photovoltaic generation and battery energy storage with the power grid, with the objective to decide on the battery (dis)charging to minimize the costs of operation. To this end, we devise a scenario-based stochastic model predictive control (MPC) scheme that leverages probabilistic 24-hour-ahead forecasts of charging load, solar generation and day-ahead electricity prices to achieve a cost-optimal operation of the energy hub. The probabilistic forecasts leverage conformal prediction providing calibrated distribution-free confidence intervals starting from a machine learning model that generates no uncertainty quantification. We showcase our controller by running it over a 280-day evaluation in a closed-loop simulated environment to compare the observed cost of two scenario-based MPCs with two deterministic alternatives: a version with point forecast and a version with perfect forecast. Our results indicate that, compared to the perfect forecast implementation, our proposed scenario-based MPCs are 11% more expensive, and 1% better than their deterministic point-forecast counterpart. © 2025, CC BY.

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Transformer-based Robust Feedback Guidance for Atmospheric Powered Landing

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Transformer-based Robust Feedback Guidance for Atmospheric P...

AIAA Science and technology Forum and Exposition, AIAA SciTech Forum 2025

作者： Carradori, Jacopo Sagliano, Marco Mooij, Erwin Section Astrodynamics and Space Mission Systems Engineering for a Mars Precision Lander ESA/ESTEC Delft University of Technology Delft Netherlands Department of Guidance Navigation and Control German Aerospace Center Bremen28359 Germany Section Astrodynamics and Space Mission Delft University of Technology Delft Netherlands

ISBN: (数字)9781624107238

ISBN: (纸本)9781624107238

Rocket reusability is a key factor in enabling quicker and more cost-effective access to space. However, landing on Earth poses significant challenges due to the dynamic and highly uncertain environment. A robust Guidance, Navigation, and control system is essential to guide the vehicle to the landing site while meeting terminal constraints and minimizing fuel consumption. This research integrates Meta-Reinforcement Learning with Gated Transformer XL Neural Networks to enhance the robustness of the powered guidance with respect to atmospheric and aerodynamic uncertainties, navigation and control errors, and dispersed initial conditions. By employing a 6-Degrees-of-Freedom dynamics model and accurate vehicle and environmental simulations, the agent learns a higher fidelity guidance policy compared to existing literature, demonstrating successful and robust performance in Monte Carlo simulations. In this complex scenario, the innovative attention-based neural networks also outperform recurrent neural networks, widely used for Reinforcement Learning-based space guidance applications. © 2025, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved.

关键词： Reusability

Continuity Conditions for Piecewise Quadratic Functions on Simplicial Conic Partitions are Equivalent

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arXiv 2025年

作者： Erlandsen, Magne Meijer, Tomas Heemels, Maurice van den Eijnden, Sebastiaan Control Systems Technology section Department of Mechanical Engineering Eindhoven University of Technology Eindhoven5600 MB Netherlands

Analysis of continuous-time piecewise linear (PWL) systems based on piecewise quadratic (PWQ) Lyapunov functions typically requires continuity of these functions over a partition of the state space. Several conditions for guaranteeing continuity of PWQ functions over state space partitions can be found in the literature. In this technical note, we show that these continuity conditions are equivalent over so-called simplicial conic partitions. A key element in our proof is a technical lemma, which, in addition to being of independent interest, plays a crucial role in demonstrating the equivalence of these conditions. As a consequence, the choice of which condition to impose can be based solely on practical considerations such as specific application or numerical aspects, without introducing additional conservatism in the analysis. © 2025, CC BY-NC-ND.

关键词： Piecewise linear techniques

Distributed Design of Ultra Large-Scale control systems: Progress, Challenges, and Prospects

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arXiv 2025年

作者： Pedroso, Leonardo Batista, Pedro Heemels, W.P.M.H. Control Systems Technology Section Eindhoven University of Technology Netherlands Institute for Systems and Robotics Instituto Superior Técnico Universidade de Lisboa Portugal

The transition from large centralized complex control systems to distributed configurations that rely on a network of a very large number of interconnected simpler subsystems is ongoing and inevitable in many applications. It is attributed to the quest for resilience, flexibility, and scalability in a multitude of engineering fields with far-reaching societal impact. Although many design methods for distributed and decentralized control systems are available, most of them rely on a centralized design procedure requiring some form of global information of the whole system. Clearly, beyond a certain scale of the network, these centralized design procedures for distributed controllers are no longer feasible and we refer to the corresponding systems as ultra large-scale systems (ULSS). For these ULSS, design algorithms are needed that are distributed themselves among the subsystems and are subject to stringent requirements regarding communication, computation, and memory usage of each subsystem. In this paper, a set of requirements is provided that assures a feasible real-time implementation of all phases of a control solution on an ultra large scale. State-of-the-art approaches are reviewed in the light of these requirements and the challenges hampering the development of befitting control algorithms are pinpointed. Comparing the challenges with the current progress leads to the identification and motivation of promising research directions. © 2025, CC BY-NC-ND.

关键词： Decentralized control

Local Rational Modeling for Identification Beyond the Nyquist Frequency: Applied to a Prototype Wafer Stage

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arXiv 2025年

作者： van Haren, Max Blanken, Lennart Classens, Koen Oomen, Tom Control Systems Technology Section Department of Mechanical Engineering Eindhoven University of Technology Eindhoven5600 MB Netherlands Sioux Technologies Eindhoven5633 AA Netherlands Delft Center for Systems and Control Delft University of Technology Delft2628 CD Netherlands

Fast-rate models are essential for control design, specifically to address intersample behavior. The aim of this paperis to develop a frequency-domain non-parametric identification technique to estimate fast-rate models of systems that have relevant dynamics and allow for actuation above the Nyquist frequency of a slow-rate output. Examples of such systems include vision-in-the-loop systems. Through local rational models over multiple frequency bands, aliased components are effectively disentangled, particularly for lightly-damped systems. The developed technique accurately determines non-parametric fast-rate models of systems with slow-rate outputs, all within a single identification experiment. Finally, the effectiveness of the technique is demonstrated through experiments conducted on a prototype wafer stage used for semiconductor manufacturing. © 2025, CC BY-NC-ND.

关键词： Frequency domain analysis

From a Frequency-Domain Willems’ Lemma to Data-Driven Predictive control

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arXiv 2025年

作者： Meijer, Tomas J. Scheres, Koen J.A. Nouwens, Sven A.N. Dolk, Victor S. Heemels, W.P.M.H. Control Systems Technology Section Department of Mechanical Engineering Eindhoven University of Technology P.O. Box 513 Eindhoven5600 MB Netherlands

Willems’ fundamental lemma has recently received an impressive amount of attention from the (data-driven) control community. In this paper, we formulate a version of this celebrated result based on frequency-domain data. In doing so, we bridge the gap between recent developments in data-driven analysis and control, and the readily-available techniques and extensive expertise for non-parametric frequency-domain identification in academia and industry. In addition, we generalize our results to allow multiple frequency-domain data sets to be carefully combined to form a sufficiently rich data set. Building on these results, we propose a data-driven predictive control scheme based on measured frequency-domain data of the plant. This novel scheme provides a frequency-domain counterpart of the well-known data-enabled predictive control scheme DeePC based on time-domain data. We prove that, under appropriate conditions, the new frequency-domain data-driven predictive control (FreePC) scheme is equivalent to the corresponding DeePC scheme, and we demonstrate the benefits of FreePC and the use of frequency-domain data in a numerical case study. These benefits include the ability to collect data in closed loop with a pre-stabilizing controller, dealing with noisy data, without increasing computational complexity, and intuitively visualizing the uncertainty in the frequency-domain data. In addition, we further showcase the potential of our frequency-domain Willems’ fundamental lemma in applications to data-driven simulation, and the linear-quadratic regulator (LQR) problem. Finally, we show that our results can be used to evaluate the transfer function of the system at a desired frequency based on a finite amount of frequency-domain data. © 2025, CC BY-NC-ND.

关键词： Predictive control systems

Leveraging Non-Steady-State Frequency-Domain Data in Willems’ Fundamental Lemma

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arXiv 2025年

作者： Meijer, T.J. Wind, M. Dolk, V.S. Heemels, W.P.M.H. Control Systems Technology Section Department of Mechanical Engineering Eindhoven University of Technology P.O. Box 513 Eindhoven5600 MB Netherlands

Willems’ fundamental lemma enables data-driven analysis and control by characterizing an unknown system’s behavior directly in terms of measured data. In this work, we extend a recent frequency-domain variant of this result–previously limited to steady-state data–to incorporate non-steady-state data including transient phenomena. This approach eliminates the need to wait for transients to decay during data collection, significantly reducing the experiment duration. Unlike existing frequency-domain system identification methods, our approach integrates transient data without preprocessing, making it well-suited for direct data-driven analysis and control. We demonstrate its effectiveness by isolating transients in the collected data and performing FRF evaluation at arbitrary frequencies in a numerical case study including noise. © 2025, CC BY-NC-ND.

关键词： Frequency domain analysis

System Identification Beyond the Nyquist Frequency: A Kernel-Regularized Approach

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arXiv 2025年

作者： van Haren, Max Smith, Roy S. Oomen, Tom Department of Mechanical Engineering Control Systems Technology Section Eindhoven University of Technology Groene Loper 5 Eindhoven5612 AE Netherlands Automatic Control Laboratory ETH Zürich Zürich8092 Switzerland Delft Center for Systems and Control Delft University of Technology Mekelweg 2 Delft2628 CN Netherlands

Models that contain intersample behavior are important for control design of systems with slow-rate outputs. The aim of this paper is to develop a system identification technique for fast-rate models of systems where only slow-rate output measurements are available, e.g., vision-in-the-loop systems. In this paper, the intersample response is estimated by identifying fast-rate models through least-squares criteria, and the limitations of these models are determined. In addition, a method is developed that surpasses these limitations and is capable of estimating unique fast-rate models of arbitrary order by regularizing the least-squares estimate. The developed method utilizes fast-rate inputs and slow-rate outputs and identifies fast-rate models accurately in a single identification experiment. Finally, both simulation and experimental validation on a prototype wafer stage demonstrate the effectiveness of the framework. © 2025, CC BY-NC-ND.

关键词： Decentralized systems