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作者： Cottrell, A. S AIR FORCE INSTITUTE OF TECHNOLOGY WRIGHT-PATTERSON AFB OH GRADUATE SCHOOL OF ENGINEERING AND MANAGEMENT AIR FORCE INSTITUTE OF TECHNOLOGY WRIGHT-PATTERSON AFB OH

Impulsive thrusters on small satellites, such as CubeSats, are typically used for attitude control. However, to become more agile, small CubeSats must also look to propulsion systems utilizing impulsive thrusters, such as cold-gas, for translational maneuvers. The combined thrust vector is often misaligned with the system's center of mass resulting in a disturbance torque. This must be counteracted by either an attitude determination and control system (ADCS), additional thrusters, or a control method to keep the satellite's attitude at or near equilibrium. Nonlinearities generated by the impulsive maneuvers are overcome via control techniques explored in this research to include on-off control, sliding mode control, and model reference adaptive control (MRAC). These methods were then compared to a baseline test without thruster modulation, where the reaction wheels must de-saturate prior to continuing the maneuver. For a 1.5 m/s delta-v maneuver, the nonlinear control techniques completed the maneuver nearly 100 times faster than the baseline, while improving pointing accuracy throughout the burn by up to 5%.

关键词： control systems Artificial satellites Spacecraft Air force control systems engineering Propulsion systems Small satellites Accuracy Cold gases engineering Modulation Physical properties Standards Thrusters United states Vehicles Algorithms

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Adaptive control Validation Using a MATLAB-Based CFD/RBD Coupled Simulation

Adaptive Control Validation Using a MATLAB-Based CFD/RBD Cou...

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作者： Sahu, J Gruenwald, B Burchett, B. T DEVCOM Army Research Laboratory Aberdeen Proving Ground MD

A new high-fidelity coupled computational fluid dynamics (CFD)/rigid body dynamics (RBD) simulation was built with several novel features aimed at validating adaptive control laws on a high-speed missile. First, the MATLAB programming language was used to implement the RBD and control laws, making the environment user-friendly for a wide community of control engineers. Second, the simulation provides for hundreds of dynamic states allowing for actuator dynamics, reference models, adaptive gains, reference signal integrators, and so forth. Third, numerical integration is performed using a multistepAdamsMoulton method such that force-moment information from prior time steps is included to smooth the predictions. With this new simulation, we demonstrate regulation and tracking control for a supersonic projectile using model reference adaptive control. The adaptive feedback law is shown to provide superior stability and tracking performance in the presence of significant modelling errors, thus achieving specified performance while reducing the precision required in gain scheduling.

关键词： Computational fluid dynamics control systems Fluid dynamics control systems engineering Three dimensional Computer programs Aircrafts Equations Military research Reliability Sea level Simulations Speed regulators Unsteady aerodynamics Aerodynamics Computations Differential equations

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Empirical Vehicle Speed Model for Tuning Throttle controller Parameters.

Empirical Vehicle Speed Model for Tuning Throttle Controller...

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作者： Jayakumar, P. Cagle, L. D. Moore, M. N. Hudson, C. H. Goodin, C. Carruth, D. W.

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The MRS UAV System: Pushing the Frontiers of Reproducible Research, Real-world Deployment, and Education with Autonomous Unmanned Aerial Vehicles

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JOURNAL OF INTELLIGENT & ROBOTIC systems 2021年第1期102卷 26-26页

作者： Baca, Tomas Petrlik, Matej Vrba, Matous Spurny, Vojtech Penicka, Robert Hert, Daniel Saska, Martin Czech Tech Univ Fac Elect Engn Multi Robot Syst Grp Tech 2 Prague Czech Republic

We present a multirotor Unmanned Aerial Vehicle (UAV) control and estimation system for supporting replicable research through realistic simulations and real-world experiments. We propose a unique multi-frame localization paradigm for estimating the states of a UAV in various frames of reference using multiple sensors simultaneously. The system enables complex missions in GNSS and GNSS-denied environments, including outdoor-indoor transitions and the execution of redundant estimators for backing up unreliable localization sources. Two feedback control designs are presented: one for precise and aggressive maneuvers, and the other for stable and smooth flight with a noisy state estimate. The proposed control and estimation pipeline are constructed without using the Euler/Tait-Bryan angle representation of orientation in 3D. Instead, we rely on rotation matrices and a novel heading-based convention to represent the one free rotational degree-of-freedom in 3D of a standard multirotor helicopter. We provide an actively maintained and well-documented open-source implementation, including realistic simulation of UAV, sensors, and localization systems. The proposed system is the product of years of applied research on multi-robot systems, aerial swarms, aerial manipulation, motion planning, and remote sensing. All our results have been supported by real-world system deployment that subsequently shaped the system into the form presented here. In addition, the system was utilized during the participation of our team from the Czech Technical University in Prague in the prestigious MBZIRC 2017 and 2020 robotics competitions, and also in the DARPA Subterranean challenge. Each time, our team was able to secure top places among the best competitors from all over the world.

关键词： Unmanned aerial systems Multirotor helicopters control systems engineering Educational robotics

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Experience with use of HIL simulators in control engineering course 21st

Experience with use of HIL simulators in control engineering...

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21st IFAC World Congress on Automatic control - Meeting Societal Challenges

作者： Goubej, Martin Langmajer, Martin Univ West Bohemia Dept Cybernet Plzen Czech Republic

The goal of the paper is to share experience with the use of hardware-in-the-loop (HIL) simulators in a control-engineering course being taught at the University of West Bohemia. The hardware simulators were introduced recently in the course curriculum aiming to get more realistic application scenarios for the students. They allow simple explanation of the concepts of model-based systems engineering in a form close to the workflow used in industrial practice. The achieved results show some significant benefits when compared to former course content, which relied on numerical simulations only. The paper presents one of the application use-cases dealing with the problem of active car suspension control. Individual phases of the control system development as done by students are explained step by step, revealing the main benefits of the hands-on experience with the physical setup. Copyright (C) 2020 The Authors.

关键词： control education automatic control control systems engineering hardware-in-the-loop simulation model-based design quarter-car system

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Framework for Autonomous Cooperative Optimal Assignment and control of Multi-Agent systems

Framework for Autonomous Cooperative Optimal Assignment and ...

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作者： Saunders, D. E AIR FORCE INSTITUTE OF TECHNOLOGY WRIGHT-PATTERSON AFB OH GRADUATE SCHOOL OF ENGINEERING AND MANAGEMENT AIR FORCE INSTITUTE OF TECHNOLOGY WRIGHT-PATTERSON AFB OH

Space has always been a domain requiring a high degree of autonomy. The challenges presented by the required autonomy have made it difficult to accomplish complex tasks and operations with short response windows. With the growing use of multiagent systems to enhance old and demonstrate new capabilities in the aerial domain, the need for development in multi-agent operations on orbit and in proximity operations has never been greater. A decentralized, cooperative multi-agent optimal control framework is presented to offer a solution to the assignment and control problems associated with performing multi-agent tasks in a proximity operations environment. However, the framework developed may be applied to a variety domains such as air, space, and sea. The solution presented takes advantage of a second price auction assignment algorithm to optimally task each satellite, while model predictive control is implemented to control the agents optimally while adhering to safety and mission constraints. The solution is compared to a direct orthogonal collocation method, and a study on tuning parameters is included. Results demonstrate the proposed technique allows the user to optimize control beyond phase horizons with Model Predictive control and achieve a formation rendezvous with three tuning parameters. This better approximates phase transition in collocation techniques compared to traditional multi-phase MPC.

关键词： control systems Computational science Collision avoidance Model predictive control Space force Spacecraft Air force Algorithms Artificial satellites Computational fluid dynamics Department of defense Autonomous systems control systems engineering Guidance Multiagent systems Elliptical orbits Equations of motion

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Robust control of an off Road Single Wheel Module Using Sliding Mode control and Fuzzy Logic Corrector

Robust Control of an off Road Single Wheel Module Using Slid...

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作者： Ghasemi, M Gorsich, D Vantsevich, V Moradi, L Paldan, J Cole, M Goryca, J Singh, A US Army Combat Capabilities Development Command Ground Vehicle Systems Center Warren MI

In this paper, the linear speed tracking control problem of a single-wheel module (SWM) operating in an offroad environment is discussed. The approach is an extension to the authors previous work for angular speed control based on sliding mode control methodology. The linear speed tracking is performed by incorporating an adjusted reference angular speed. This reference speed is constructed utilizing a proportional control method. Further, two different approaches for tire slippage suppression are proposed. Both methods provide a corrected reference angular speed such that tracking it limits the tire slippage growth. The first method utilizes a predefined slippage limit, while the second method bounds the slippage by considering a range of characteristic slippages corresponding to different tire-terrain attributes. The second method is based on fuzzy logic control and specifically is designed according to Mamdani fuzzy inference system and is called the fuzzy logic corrector in this paper. The efficacy of the controlled system is evaluated through numerical simulations. It is shown that the system is able to robustly track the reference linear speed while it suppresses the tire slippage.

关键词： control systems Closed loop systems control systems engineering Electric vehicles Electric motors Fuzzy logic Maneuverability Motors Surfaces Vehicles control theory Efficiency Energy efficiency engineering Dc motors Dynamics Environment

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Building Automation System Enumeration and Configuration (BASEC).

Building Automation System Enumeration and Configuration (BA...

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作者： Butts, J. Rios, B.

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Model predictive control for MR-HIFU-mediated, uniform hyperthermia

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INTERNATIONAL JOURNAL OF HYPERTHERMIA 2019年第1期36卷 1040-1050页

作者： Sebeke, L. Deenen, D. A. Maljaars, E. Heijman, E. de Jager, B. Heemels, W. P. M. H. Gruell, H. Eindhoven Univ Technol Dept Mech Engn Computat Biol Eindhoven Netherlands Univ Cologne Fac Med Cologne Germany Univ Cologne Univ Hosp Cologne Dept Diagnost & Intervent Radiol Cologne Germany Eindhoven Univ Technol Dept Mech Engn Control Syst Technol Eindhoven Netherlands Philips Res Eindhoven Eindhoven Netherlands

Purpose: In local hyperthermia, precise temperature control throughout the entire target region is key for swift, safe, and effective treatment. In this article, we present a model predictive control (MPC) algorithm providing voxel-level temperature control in magnetic resonance-guided high intensity focused ultrasound (MR-HIFU) and assess the improvement in performance it provides over the current state of the art. Materials and methods: The influence of model detail on the prediction quality and runtime of the controller is evaluated and a tissue mimicking phantom is characterized using the resulting model. Next, potential problems arising from modeling errors are evaluated in silico and in the characterized phantom. Finally, the controller?s performance is compared to the current state-of-the-art hyperthermia controller in side-by-side experiments. Results: Modeling diffusion by heat exchange between four neighboring voxels achieves high predictive performance and results in runtimes suited for real-time control. Erroneous model parameters deteriorate the MPC?s performance. Using models derived from thermometry data acquired during low powered test sonications, however, high control performance is achieved. In a direct comparison with the state-of-the-art hyperthermia controller, the MPC produces smaller tracking errors and tighter temperature distributions, both in a homogeneous target and near a localized heat sink. Conclusion: Using thermal models deduced from low-powered test sonications, the proposed MPC algorithm provides good performance in phantoms. In direct comparison to the current state-of-the-art hyperthermia controller, MPC performs better due to the more finely tuned heating patterns and therefore constitutes an important step toward stable, uniform hyperthermia.

关键词： High intensity focused ultrasound noninvasive thermometry modeling control systems engineering treatment optimization hyperthermia phantom tissue-mimick perfusion

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Experience with use of HIL simulators in control engineering course

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IFAC-PapersOnLine 2020年第2期53卷 17308-17313页

作者： Martin Goubej Martin Langmajer University of West Bohemia Department of Cybernetics Pilsen Czech Republic

关键词： control education automatic control control systems engineering hardware-in-the-loop simulation model-based design quarter-car system

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