scholarly journals Observer Design for Nonlinear Systems with Equivariance

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Robert Mahony ◽  
Pieter van Goor ◽  
Tarek Hamel
Keyword(s):  
State Space ◽  
Kalman Filtering ◽  
High Performance ◽  
Autonomous Systems ◽  
Observer Design ◽  
Annual Review ◽  
Publication Date ◽  
Navigation Systems ◽  
Extended Kalman Filtering ◽  
Wide Range

Equivariance is a common and natural property of many nonlinear control systems, especially those associated with models of mechatronic and navigation systems. Such systems admit a symmetry, associated with the equivariance, that provides structure enabling the design of robust and high-performance observers. A key insight is to pose the observer state to lie in the symmetry group rather than on the system state space. This allows one to define a global intrinsic equivariant error but poses a challenge in defining internal dynamics for the observer. By choosing an equivariant lift of the system dynamics for the observer internal model, we show that the error dynamics have a particularly nice form. Applying the methodology of extended Kalman filtering to the equivariant error state yields a filter we term the equivariant filter. The geometry of the state-space manifold appears naturally as a curvature modification to the classical Riccati equation for extended Kalman filtering. The equivariant filter exploits the symmetry and respects the geometry of an equivariant system model, and thus yields high-performance, robust filters for a wide range of mechatronic and navigation systems. Expected final online publication date for the Annual Review of Control, Robotics, and Autonomous Systems, Volume 5 is May 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Flood Inundation Prediction

2021 ◽  
Vol 54 (1) ◽  
Author(s):  
Paul D. Bates
Keyword(s):  
Fluid Mechanics ◽  
Land Surface ◽  
High Performance ◽  
Numerical Algorithms ◽  
Economic Damage ◽  
Annual Review ◽  
Publication Date ◽  
Flood Inundation ◽  
Damage Mapping ◽  
Performance Computing

Every year flood events lead to thousands of casualties and significant economic damage. Mapping the areas at risk of flooding is critical to reducing these losses, yet until the last few years such information was available for only a handful of well-studied locations. This review surveys recent progress to address this fundamental issue through a novel combination of appropriate physics, efficient numerical algorithms, high-performance computing, new sources of big data, and model automation frameworks. The review describes the fluid mechanics of inundation and the models used to predict it, before going on to consider the developments that have led in the last five years to the creation of the first true fluid mechanics models of flooding over the entire terrestrial land surface. Expected final online publication date for the Annual Review of Fluid Mechanics, Volume 54 is January 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Thermoelectrics by Computational Design: Progress and Opportunities

2021 ◽  
Vol 51 (1) ◽  
Author(s):  
Boris Kozinsky ◽  
David J. Singh
Keyword(s):  
First Principles ◽  
High Performance ◽  
Materials Science ◽  
Phonon Scattering ◽  
Transport Coefficients ◽  
Computational Design ◽  
Science Volume ◽  
Annual Review ◽  
Publication Date ◽  
Boltzmann Transport

The performance of thermoelectric materials is determined by their electrical and thermal transport properties that are very sensitive to small modifications of composition and microstructure. Discovery and design of next-generation materials are starting to be accelerated by computational guidance. We review progress and challenges in the development of accurate and efficient first-principles methods for computing transport coefficients and illustrate approaches for both rapid materials screening and focused optimization. Particularly important and challenging are computations of electron and phonon scattering rates that enter the Boltzmann transport equations, and this is where there are many opportunities for improving computational methods. We highlight the first successful examples of computation-driven discoveries of high-performance materials and discuss avenues for tightening the interaction between theoretical and experimental materials discovery and optimization. Expected final online publication date for the Annual Review of Materials Science, Volume 51 is August 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Design and Control of Drones

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Mark W. Mueller ◽  
Seung Jae Lee ◽  
Raffaello D’Andrea
Keyword(s):  
Energy Consumption ◽  
Motion Planning ◽  
Recent Progress ◽  
Scaling Laws ◽  
Autonomous Systems ◽  
Annual Review ◽  
Publication Date ◽  
Trade Offs ◽  
Active Research ◽  
And Control

The design and control of drones remain areas of active research, and here we review recent progress in this field. In this article, we discuss the design objectives and related physical scaling laws, focusing on energy consumption, agility and speed, and survivability and robustness. We divide the control of such vehicles into low-level stabilization and higher-level planning such as motion planning, and we argue that a highly relevant problem is the integration of sensing with control and planning. Lastly, we describe some vehicle morphologies and the trade-offs that they represent. We specifically compare multicopters with winged designs and consider the effects of multivehicle teams. Expected final online publication date for the Annual Review of Control, Robotics, and Autonomous Systems, Volume 5 is May 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Secure Networked Control Systems

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Henrik Sandberg ◽  
Vijay Gupta ◽  
Karl H. Johansson
Keyword(s):  
Control Systems ◽  
Critical Infrastructure ◽  
Networked Control Systems ◽  
Denial Of Service ◽  
Autonomous Systems ◽  
Mitigation Strategies ◽  
Networked Control ◽  
Annual Review ◽  
Publication Date ◽  
Process Industries

Cyber-vulnerabilities are being exploited in a growing number of control systems. As many of these systems form the backbone of critical infrastructure and are becoming more automated and interconnected, it is of the utmost importance to develop methods that allow system designers and operators to do risk analysis and develop mitigation strategies. Over the last decade, great advances have been made in the control systems community to better understand cyber-threats and their potential impact. This article provides an overview of recent literature on secure networked control systems. Motivated by recent cyberattacks on the power grid, connected road vehicles, and process industries, a system model is introduced that covers many of the existing research studies on control system vulnerabilities. An attack space is introduced that illustrates how adversarial resources are allocated in some common attacks. The main part of the article describes three types of attacks: false data injection, replay, and denial-of-service attacks. Representative models and mathematical formulations of these attacks are given along with some proposed mitigation strategies. The focus is on linear discrete-time plant models, but various extensions are presented in the final section, which also mentions some interesting research problems for future work. Expected final online publication date for the Annual Review of Control, Robotics, and Autonomous Systems, Volume 5 is May 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Stimuli-Responsive Polymers for Soft Robotics

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Yusen Zhao ◽  
Mutian Hua ◽  
Yichen Yan ◽  
Shuwang Wu ◽  
Yousif Alsaid ◽  
...  
Keyword(s):  
Autonomous Systems ◽  
Soft Robotics ◽  
Annual Review ◽  
Liquid Crystal Polymers ◽  
Publication Date ◽  
Stimuli Responsive ◽  
Stimuli Responsive Polymers ◽  
Responsive Polymers ◽  
Evaluation Of Performance ◽  
Robotic Applications

This article reviews recent progress in the use of stimuli-responsive polymers for soft robotics. First, we introduce different types of representative stimuli-responsive polymers, which include liquid crystal polymers and elastomers, hydrogels, shape memory polymers, magnetic elastomers, electroactive polymers, and thermal expansion actuators. We focus on the mechanisms of actuation and the evaluation of performance and discuss strategies for improvements. We then present examples of soft robotic applications based on stimuli-responsive polymers for bending, grasping, walking, swimming, flying, and sensing control. Finally, we discuss current opportunities and challenges of stimuli-responsive soft robots for future study. Expected final online publication date for the Annual Review of Control, Robotics, and Autonomous Systems, Volume 5 is May 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Methods for Robot Behavior Adaptation for Cognitive Neurorehabilitation

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Alyssa Kubota ◽  
Laurel D. Riek
Keyword(s):  
State Of The Art ◽  
Cognitive Impairments ◽  
Autonomous Systems ◽  
Behavioral Adaptation ◽  
Annual Review ◽  
Publication Date ◽  
Pharmacological Treatments ◽  
Robot Behavior ◽  
Behavioral Treatments ◽  
Physical Abilities

An estimated 11% of adults report experiencing some form of cognitive decline, which may be associated with conditions such as stroke or dementia and can impact their memory, cognition, behavior, and physical abilities. While there are no known pharmacological treatments for many of these conditions, behavioral treatments such as cognitive training can prolong the independence of people with cognitive impairments. These treatments teach metacognitive strategies to compensate for memory difficulties in their everyday lives. Personalizing these treatments to suit the preferences and goals of an individual is critical to improving their engagement and sustainment, as well as maximizing the treatment's effectiveness. Robots have great potential to facilitate these training regimens and support people with cognitive impairments, their caregivers, and clinicians. This article examines how robots can adapt their behavior to be personalized to an individual in the context of cognitive neurorehabilitation. We provide an overview of existing robots being used to support neurorehabilitation and identify key principles for working in this space. We then examine state-of-the-art technical approaches for enabling longitudinal behavioral adaptation. To conclude, we discuss our recent work on enabling social robots to automatically adapt their behavior and explore open challenges for longitudinal behavior adaptation. This work will help guide the robotics community as it continues to provide more engaging, effective, and personalized interactions between people and robots. Expected final online publication date for the Annual Review of Control, Robotics, and Autonomous Systems, Volume 5 is May 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

The Basis of Navigation Across Species

2021 ◽  
Vol 73 (1) ◽  
Author(s):  
Cody A. Freas ◽  
Ken Cheng
Keyword(s):  
Large Scale ◽  
Error Reduction ◽  
Annual Review ◽  
Publication Date ◽  
Additional Component ◽  
Oscillatory Systems ◽  
Neural Architecture ◽  
Wide Range ◽  
Reduction Strategies ◽  
Cycling Behavior

Animals navigate a wide range of distances, from a few millimeters to globe-spanning journeys of thousands of kilometers. Despite this array of navigational challenges, similar principles underlie these behaviors across species. Here, we focus on the navigational strategies and supporting mechanisms in four well-known systems: the large-scale migratory behaviors of sea turtles and lepidopterans as well as navigation on a smaller scale by rats and solitarily foraging ants. In lepidopterans, rats, and ants we also discuss the current understanding of the neural architecture which supports navigation. The orientation and navigational behaviors of these animals are defined in terms of behavioral error-reduction strategies reliant on multiple goal-directed servomechanisms. We conclude by proposing to incorporate an additional component into this system: the observation that servomechanisms operate on oscillatory systems of cycling behavior. These oscillators and servomechanisms comprise the basis for directed orientation and navigational behaviors. Expected final online publication date for the Annual Review of Psychology, Volume 73 is January 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Engineering Advances in Spray Drying for Pharmaceuticals

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
John M. Baumann ◽  
Molly S. Adam ◽  
Joel D. Wood
Keyword(s):  
Spray Drying ◽  
Oral Delivery ◽  
Process Development ◽  
Solid Dispersions ◽  
Amorphous Solid ◽  
Annual Review ◽  
Publication Date ◽  
Dry Powders ◽  
Wide Range ◽  
Pharmaceutical Industries

Spray drying is a versatile technology that has been applied widely in the chemical, food, and, most recently, pharmaceutical industries. This review focuses on engineering advances and the most significant applications of spray drying for pharmaceuticals. An in-depth view of the process and its use is provided for amorphous solid dispersions, a major, growing drug-delivery approach. Enhanced understanding of the relationship of spray-drying process parameters to final product quality attributes has made robust product development possible to address a wide range of pharmaceutical problem statements. Formulation and process optimization have leveraged the knowledge gained as the technology has matured, enabling improved process development from early feasibility screening through commercial applications. Spray drying's use for approved small-molecule oral products is highlighted, as are emerging applications specific to delivery of biologics and non-oral delivery of dry powders. Based on the changing landscape of the industry, significant future opportunities exist for pharmaceutical spray drying. Expected final online publication date for the Annual Review of Chemical and Biomolecular Engineering, Volume 12 is June 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Chemical Stability of Proteins in Foods: Oxidation and the Maillard Reaction

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Mahesha M. Poojary ◽  
Marianne N. Lund
Keyword(s):  
Maillard Reaction ◽  
Protein Oxidation ◽  
Oxidation Products ◽  
Protein Carbonyls ◽  
Annual Review ◽  
Publication Date ◽  
Food Protein ◽  
Food Proteins ◽  
Wide Range ◽  
Specific Oxidation

Protein is a major nutrient present in foods along with carbohydrates and lipids. Food proteins undergo a wide range of modifications during food production, processing, and storage. In this review, we discuss two major reactions, oxidation and the Maillard reaction, involved in chemical modifications of food proteins. Protein oxidation in foods is initiated by metal-, enzyme-, or light-induced processes. Food protein oxidation results in the loss of thiol groups and the formation of protein carbonyls and specific oxidation products of cysteine, tyrosine, tryptophan, phenylalanine, and methionine residues, such as disulfides, dityrosine, kynurenine, m-tyrosine, and methionine sulfoxide. The Maillard reaction involves the reaction of nucleophilic amino acid residues with reducing sugars, which yields numerous heterogeneous compounds such as α-dicarbonyls, furans, Strecker aldehydes, advanced glycation end-products, and melanoidins. Both protein oxidation and the Maillard reaction result in the loss of essential amino acids but may positively or negatively impact food structure and flavor. Expected final online publication date for the Annual Review of Food Science and Technology, Volume 13 is March 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

scholarly journals Set Propagation Techniques for Reachability Analysis

2020 ◽  
Vol 4 (1) ◽  
Author(s):  
Matthias Althoff ◽  
Goran Frehse ◽  
Antoine Girard
Keyword(s):  
Hybrid Systems ◽  
Fundamental Problem ◽  
Autonomous Systems ◽  
Reachability Analysis ◽  
Controller Synthesis ◽  
Annual Review ◽  
Publication Date ◽  
Initial States ◽  
Set Of Initial States ◽  
Real World Problems

Reachability analysis consists in computing the set of states that are reachable by a dynamical system from all initial states and for all admissible inputs and parameters. It is a fundamental problem motivated by many applications in formal verification, controller synthesis, and estimation, to name only a few. This article focuses on a class of methods for computing a guaranteed overapproximation of the reachable set of continuous and hybrid systems, relying predominantly on set propagation; starting from the set of initial states, these techniques iteratively propagate a sequence of sets according to the system dynamics. After a review of set representation and computation, the article presents the state of the art of set propagation techniques for reachability analysis of linear, nonlinear, and hybrid systems. It ends with a discussion of successful applications of reachability analysis to real-world problems. Expected final online publication date for the Annual Review of Control, Robotics, and Autonomous Systems, Volume 4 is May 3, 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

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