Tracking Properties Research Articles

Synthetic Vs. Real Driving Cycles: A Comparison of EV Battery Degradation

Automobile dependency and the inexorable proliferation of electric vehicles (EV) compels accurate predictions of cycle life across multiple usage conditions and for multiple lithium-ion battery systems. Synthetic driving cycles have been essential in accumulating data on EV battery lifetimes. However, since battery deterioration is path-dependent, the representability of synthetic cycles must be questioned. Hence, this work compared three different synthetic driving cycles to real-driving data in terms of mimicking actual EV battery degradation. It was found that the average current and charge capacity during discharge were important parameters in determining the appropriate synthetic profile and traffic conditions have a significant impact on cell lifetimes. In addition, a stage of accelerated capacity fade was observed and shown to be induced by an increased loss of lithium inventory (LLI) resulting from irreversible Li plating. New metrics, the ratio of the loss of active material at the negative electrode (LAMNE) to the LLI and the plating threshold, were proposed as possible predictors for a stage of accelerated degradation. The results presented here demonstrate tracking properties such as capacity loss and resistance increase were insufficient in predicting cell lifetimes and support the adoption of metrics based on the analysis of degradation modes.

Slow manifolds for a nonlocal fast-slow stochastic system with stable Lévy noise

This work aims at understanding the slow dynamics of a nonlocal fast-slow stochastic evolutionary system with stable Lévy noise. Slow manifolds along with the exponential tracking property for a nonlocal fast-slow stochastic evolutionary system with stable Lévy noise are constructed, and two examples with numerical simulations are presented to illustrate the results.

Transition radiation in a piecewise-linear and infinite one-dimensional structure\u2013a Laplace transform method

Transition zones in railway tracks are areas with considerable variation of track properties (i.e., foundation stiffness), encountered near structures such as bridges and tunnels. Due to strong amplification of the response, transition zones require frequent maintenance. To better understand the underlying degradation mechanisms, a one-dimensional model is formulated, consisting of an infinite Euler–Bernoulli beam resting on a locally inhomogeneous and nonlinear Winkler foundation, subjected to a moving load. The nonlinearity is characterized by a piecewise-linear stiffness, and the system thus behaves piecewise linearly. Therefore, the solution can be obtained by sequentially applying the Laplace transform combined with the Finite Difference Method for the spatial discretization and derived non-reflective boundary conditions. Results show that the plastic deformation is a consequence of constructive interference of the excited waves and the response to the load’s deadweight, particularly for the soft-to-stiff transition. The plastic deformation area decreases quasi-monotonically with increasing transition length, and for super-critical velocities, small transition lengths and/or large stiffness dissimilarities, parts of the foundation experience plastic deformation even in the second loading–unloading cycle. Furthermore, the nonlinearity causes the maximum energy associated with the waves radiated forward and the maximum energy input not to occur for the smallest transition length, contrary to findings in corresponding linear systems. Moreover, the energy input drastically increases for the second passage of the moving load, making it a possible indicator of the damage in the supporting structure. The novelty of the current work lies in the computationally efficient solution method for an infinite system which locally exhibits nonlinear behaviour and in the study into the influence of the foundation’s nonlinear behaviour on the generated waves (i.e., transition radiation), and on the resulting plastic deformation. The model presented here can be used for the preliminary design of transition zones in railway tracks.

Robust distributed consensus tracking control for high‐order uncertain nonlinear MASs with directed topologies

AbstractThis paper addresses the robust distributed consensus tracking problem for leader‐follower multi‐agent systems (MASs) with nonlinear dynamics and external disturbances under directed graph topologies. The nonlinear uncertainties are not required to be continuous or meet the matching conditions. The backstepping design method combined with signal compensation approach is proposed to design robust controllers in order to guarantee the consensus tracking property between the followers and the one leader. Moreover, the dynamic surface control technique is used to deal with the 'explosion of complexity' problem. It is proven that the robust distributed consensus tracking property of the MASs can be guaranteed. Furthermore, the consensus tracking errors can be designed as small as required and the convergence speed can be chosen arbitrarily. Finally, two examples are presented to show the validity of the proposed consensus tracking control protocols.

Construction of catechol-grafted chitosan alginate/barium sulfate microcapsules for computed tomography real-time imaging and gastroretentive drug delivery.

Background: The gastroretentive drug delivery system is an effective administration route, which can improve the bioavailability of the drug and the therapeutic effect by prolonging the release time of the drug and controlling the release rate in the stomach.Methods: Inspired by the excellent adhesion properties of mussel protein, we prepared novel catechol-grafted chitosan alginate/barium sulfate microcapsules (Cat-CA/BS MCs) with mucoadhesive properties and computed tomography (CT) imaging function for gastric drug delivery. First, barium sulfate nanoclusters used as CT contrast agent were synthesized in situ in the Cat-CA/BS MCs through a one-step electronic spinning method. Next, catechol-grafted chitosan as the mucoadhesive moiety was coated on the surface of Cat-CA/BS MCs by polyelectrolyte molecule self-assembly.Results: The prepared Cat-CA/BS MCs could effectively retained in the stomach for 48 hours and successively released ranitidine hydrochloride, which could be used for the treatment of gastric ulcer. Cat-CA/BS MCs exhibited superior CT contrast imaging properties for real-time tracking in vivo after oral administration.Conclusion: These findings demonstrate that Cat-CA/BS MCs serving as multifunctional oral drug carriers possess huge potential in gastroretentive drug delivery and non-invasive visualization.

A decoupling control for quadrotor UAV using dynamic surface control and sliding mode disturbance observer

This paper proposes a decoupling tracking controller for quadrotors using dynamic surface control (DSC) and second-order sliding mode disturbance observer (SMDO). The DSC used in this paper is improved with the sliding mode differentiators that replace the original low-pass filter, and the SMDO is utilized to restrain the influence of system uncertainties and external disturbances. In addition, instead of the roll attitude angle ( $$\varphi $$ ) and pitch attitude angle ( $$\theta $$ ), applying $$\sin {\varphi }$$ and $$\sin {\theta }$$ as control variables simplifies the analysis of stability. Moreover, a fuzzy logic-based method is utilized to compensate the influence of battery voltage changing during the procedure of thrust generation. The asymptotic tracking property of the closed-loop system is proven via the Lyapunov-based stability theory. Finally, the real-time experiment results, which contain a hovering case and rectangular path tracking case, are given to validate the practicability of the proposed method.

Event-triggered decentralized output-feedback control for interconnected nonlinear systems with input quantization

In this paper, the event-triggered decentralized control problem for interconnected nonlinear systems with input quantization is investigated. A state observer is constructed to estimate the unmeasurable states, and the state-dependent interconnections are accommodated by presenting some smooth functions. Then by employing backstepping technique and neural networks (NNs) approximation capability, a novel decentralized output feedback control strategy and an event-triggered mechanism are designed simultaneously. It is proved through Lyapunov theory that the closed-loop system is stable and the tracking property of all subsystems is guaranteed. Finally, the effectiveness of the proposed scheme is illustrated by an example.

Design optimization of a pixel-based range telescope for proton computed tomography

PurposeA pixel-based range telescope for tracking particles during proton imaging is described. The detector applies a 3D matrix of stacked Monolithic Active Pixel Sensors with fast readout speeds. This study evaluates different design alternatives of the range telescope on basis of the protons’ range accuracy and the track reconstruction efficiency. MethodDetector designs with different thicknesses of the energy-absorbing plates between each sensor layer are simulated using the GATE/Geant4 Monte Carlo software. Proton tracks traversing the detector layers are individually reconstructed, and a Bragg curve fitting procedure is applied for the calculation of each proton’s range. ResultsSimulations show that the setups with 4 mm and thinner absorber layers of aluminum have a low range uncertainty compared to the physical range straggling, systematic errors below 0.3 mm water equivalent thickness and a track reconstruction capability exceeding ten million protons per second. ConclusionsIn order to restrict the total number of layers and to yield the required tracking and range resolution properties, a design recommendation is reached where the proposed range telescope applies 3.5 mm thick aluminum absorber slabs between each sensor layer.

Tracking the Reflective Light Particles Spreading on the Cornea: An Emerging Assessment for Tear Film Homeostasis.

PurposeTo implement an emerging noninvasive approach for assessing the dynamic tear film (TF) homeostasis.MethodsThe video records of dynamic TF from 12 healthy orthokeratology lens wearers were obtained by a clinically available TF analyzer and decomposed as image sequences. The trajectories of TF particles were analyzed by two tracking models, the full-span model (FSM) and the fixed-duration model (FDM). FSM tracked a particle for a complete opening blink cycle, while FDM tracked 1 second of the same cycle. A power-law fitting operation newcommand{bialpha}{boldsymbol{alpha}}newcommand{bibeta}{boldsymbol{beta}}newcommand{bigamma}{boldsymbol{gamma}}newcommand{bidelta}{boldsymbol{delta}}newcommand{bivarepsilon}{boldsymbol{varepsilon}}newcommand{bizeta}{boldsymbol{zeta}}newcommand{bieta}{boldsymbol{eta}}newcommand{bitheta}{boldsymbol{theta}}newcommand{biiota}{boldsymbol{iota}}newcommand{bikappa}{boldsymbol{kappa}}newcommand{bilambda}{boldsymbol{lambda}}newcommand{bimu}{boldsymbol{mu}}newcommand{binu}{boldsymbol{nu}}newcommand{bixi}{boldsymbol{xi}}newcommand{biomicron}{boldsymbol{micron}}newcommand{bipi}{boldsymbol{pi}}newcommand{birho}{boldsymbol{rho}}newcommand{bisigma}{boldsymbol{sigma}}newcommand{bitau}{boldsymbol{tau}}newcommand{biupsilon}{boldsymbol{upsilon}}newcommand{biphi}{boldsymbol{phi}}newcommand{bichi}{boldsymbol{chi}}newcommand{bipsi}{boldsymbol{psi}}newcommand{biomega}{boldsymbol{omega}}{rm{MMS}}left( t right) = {rm{alpha }} times {t^{ - {rm{beta }}}} was used to extract homeostasis markers based on the tracking model for each subject.ResultsComparing two tracking models (N = 6), only one subject had statistical difference in averaged momentary moving speed (MMS; P = 0.0488), while none had significant difference in averaged momentary moving direction (MMD). However, both models showed good correlations in average MMS (ρ = 0.94, P = 0.0048) and MMD (ρ = 1.00, P < 0.0001) and all extracted homeostasis markers [α, β, MMS(0.1), and MMS(2.0)]. Assessing interblink reliability in these markers under FDM tracking (N = 12), only one subject in the MMS (0.1) and another subject in the MMS (2.0) were outside 95% limits of agreement, respectively.ConclusionsFDM is a good alternative to FSM and has tracking properties of higher efficiency and easier implementation. The homeostasis markers under FDM tracking showed a good interblink consistence; therefore this approach will be a promising method for analyzing dynamic TF homeostasis in future practice.Translational RelevanceFDM analytical architecture can practice the past experimental platform on a TF analyzer to obtain homeostasis markers of TF.

Global mapping of asteroids by frozen orbits: The case of 216 kleopatra

In this paper, the global mapping of an irregular asteroid is studied referring to the ground track properties of a frozen orbit (at constant eccentricity and argument of pericentre on average). In fact, when the size of the asteroid is in the order of hundreds of kilometres or more, an appropriate design of the ground track becomes an important element to optimise the coverage and guarantee regular cycles of observation. To this end, the methodology used to design the ground track in missions for the observation of regular bodies, like planets, is extended to the case of irregular bodies, such as asteroids. Moreover, to manage the irregular shape of the asteroid, the classical spherical coordinates (geographical longitude and latitude) are replaced by cylindrical coordinates, whereas the regions that are not reached by the ground track are modelled by using appropriate tetrahedra, useful to plan the coverage. In this context, the case of asteroid 216 Kleopatra has been investigated.

Railway track degradation: The contribution of a spatially variant support stiffness - Local variation

This study addresses the contribution of spatial variance in the railway track support stiffness to the expected long-term track degradation. Hereto, a novel frequency-domain model is developed with a double periodicity ‘layer’, capable of dealing with both sleeper periodicity and arbitrary non-uniformity in track properties. The model application focuses on a locally reduced support stiffness (hanging sleeper) along the track. The resulting susceptibility to degradation is assessed by quantifying the mechanical energy dissipated over the influence length under a moving train axle. Different descriptions of this energy amount are benchmarked with respect to their predictive value. In the presence of a degraded sleeper support, hanging sleepers are found to develop faster with increasing train speed; the speed effect may be estimated as roughly linear. Moreover, degradation increases progressively with an increasing local relative stiffness reduction. Coincidence of the train speed corresponding to the sleeper passing frequency with the first resonance peak of the system leads to severely increased degradation; increased damping however attenuates dissipation peaks at resonant speeds and shifts their position upwards. The effect of a degraded support is most significant on soft subgrades. The effect of multiple degraded sleeper supports increases up to three sleepers, for any train speed. With respect to the system parameters, particularly the railpad stiffness has significant effect; especially for high-speed tracks a high pad stiffness is very unfavorable. Other effective control parameters in the case of degraded sleeper supports are the sleeper spacing and the rail cross-sectional properties; for example replacing a 54E1 with a 60E1 rail profile may reduce energy dissipation with roughly 30% on high-speed track. An increasing unsprung vehicle mass is unfavorable for track degradation, again with the effect increasing with the train speed. The developed methodology is shown to have significant potential with respect to railway track design in terms of multi-parametric optimization for concrete cases with a given input in terms of soil properties and operational regime.

An investigation of the influence of thermal process on the electrical conductivity of LIFT printed Cu structures

The electrical properties of copper tracks printed by laser-induced-forward-transfer (LIFT) are typically inferior to the bulk values. Several limiting factors have been indicated such as oxidation, droplet boundaries and grain boundaries. However, the relative contribution of each of these factors has not been determined. To improve the electrical properties of LIFT printed structures, an analysis of various factors is essential. Here, we concentrate on the effect of post-printing thermal treatment on LIFT printed copper structures. A reduction in electrical resistivity by a factor of ~3 is obtained resulting in a value lower than 3 times the bulk copper value (1.68 µΩ · cm). Real time resistance measurements indicate that an efficient thermal annealing can be achieved at 200 °C–300 °C within a couple of minutes. The morphological changes associated with such thermal treatment were analyzed using HR-SEM and XRD and highlight the role of stress relief, grain growth and formation of new grains primarily at the inter-droplet interfaces.

A Design Method for Linear Motion Servocontrol System

This paper proposes some practical methodology and design aids for the linear motion servocontrol systems such as the electromagnetic launchers. Mason’s gain formula was first used in the state space to solve for the transfer function of the complex and multiloop system rapidly and conveniently. The classical feedback control referring to the separation principle, involving a tracking controller and an observer-based compensator, may work well but has limited bandwidth under the constraint of the nominal inertia, and this fact is demonstrated rigorously in this paper and improved by a novel compensation scheme. According to the time-domain performance and Nyquist view, a delicate parameter design of control parameters is made for the tracking controller and the robust observer. The algorithm is verified by use of a rapid control prototype real-time simulation platform. The comparison of the experimental results shows that the proposed control scheme has good properties of trajectory tracking, antidisturbance, and noise suppression.

Synthetic vs. Real Driving Cycles: A Comparison of Electric Vehicle Battery Degradation

Automobile dependency and the inexorable proliferation of electric vehicles (EVs) compels accurate predictions of cycle life across multiple usage conditions and for multiple lithium-ion battery systems. Synthetic driving cycles have been essential in accumulating data on EV battery lifetimes. However, since battery deterioration is path-dependent, the representability of synthetic cycles must be questioned. Hence, this work compared three different synthetic driving cycles to real driving data in terms of mimicking actual EV battery degradation. It was found that the average current and charge capacity during discharge were important parameters in determining the appropriate synthetic profile, and traffic conditions have a significant impact on cell lifetimes. In addition, a stage of accelerated capacity fade was observed and shown to be induced by an increased loss of lithium inventory (LLI) resulting from irreversible Li plating. New metrics, the ratio of the loss of active material at the negative electrode (LAMNE) to the LLI and the plating threshold, were proposed as possible predictors for a stage of accelerated degradation. The results presented here demonstrated tracking properties, such as capacity loss and resistance increase, were insufficient in predicting cell lifetimes, supporting the adoption of metrics based on the analysis of degradation modes.

Distributed Fault-Tolerant Control of Multiagent Systems: An Adaptive Learning Approach.

This paper focuses on developing a distributed leader-following fault-tolerant tracking control scheme for a class of high-order nonlinear uncertain multiagent systems. Neural network-based adaptive learning algorithms are developed to learn unknown fault functions, guaranteeing the system stability and cooperative tracking even in the presence of multiple simultaneous process and actuator faults in the distributed agents. The time-varying leader's command is only communicated to a small portion of follower agents through directed links, and each follower agent exchanges local measurement information only with its neighbors through a bidirectional but asymmetric topology. Adaptive fault-tolerant algorithms are developed for two cases, i.e., with full-state measurement and with only limited output measurement, respectively. Under certain assumptions, the closed-loop stability and asymptotic leader-follower tracking properties are rigorously established.

Исследование влияния режимов фокусировки лазерного излучения на геометрические и механические свойства металлокерамических треков

Исследование влияния режимов фокусировки лазерного излучения на геометрические и механические свойства металлокерамических треков

Generalized active disturbance rejection control for the boiler-turbine unit using multi-objective optimization and extended state observer

This paper proposes a generalized active disturbance rejection controller (GADRC) based hierarchical control structure for the boilerturbine unit. In the lower layer, a multivariable extended state observer (MESO) is developed to estimate the values of the lumped disturbances caused by modelling mismatches, fuel quality variation and wide range load variation. The influence of the disturbances is then compensated at the input side as a feedforward control. In the upper layer, the multi-objective optimization is devised to obtain the set-points by removing the plant behaviour variation from the optimized model in a feasible way. The lowpass filter acting on the lumped disturbances is designed to bridge the gap between the lower and upper layer. The impact of the feedthrough item is approximated by a first-order system and a two degree-of-freedom (2-DOF) control strategy is established to illustrate the set-point tracking and disturbance rejection properties of the controller. Simulation studies on a 1000MWe coal-fired ultra-supercritical boiler-turbine unit demonstrate that the proposed control strategy can achieve a satisfactory performance in cases of fuel quality variations, model-plant mismatches and wide range load variation.

Application of Fractional Order Sliding Mode Control for Speed Control of Permanent Magnet Synchronous Motor

This paper investigates speed regulation of permanent magnet synchronous motor (PMSM) system based on sliding mode control (SMC). Sliding mode control has been vastly applied for speed control of PMSM. However, continuous SMC enhancement studies are executed to improve the performance of conventional SMC in terms of tracking and disturbance rejection properties as well as to reduce chattering effects. By introducing fractional calculus in the sliding mode manifold, a novel fractional order sliding mode controller is proposed for the speed loop. The proposed fractional order sliding mode speed controller is designed with a sliding surface that consists of both fractional differentiation and integration. Stability of the proposed controller is proved using Lyapunov stability theorem. The simulation and experimental results show the superiorities of the proposed method in terms of faster convergence, better tracking precision and better anti-disturbance rejection properties. In addition, chattering effect of this enhanced SMC is smaller compared to those of conventional SMC. Last but not least, a comprehensive comparison table summarizes key performance indexes of the proposed controller with respect to conventional integer order controller.

The Possibilities of Supporting the Public Functions with Fleet and Force Tracking Systems

The variable tracking systems for troops monitoring on field were popular for espionage in the 1980s and 1990s. Then they became essential materials for the action movies of the 21st century. Due to the rapid development of information technologies, the different navigation methods, systems and tools, this is now a 24/7 service and can be purchased by anyone to have detections and observations of the actions of vehicles, groups of people, individuals or even animals. From the number of variable options available for navigation, the applicable procedures are based on radio frequencies, even within that, those solutions that work in the frame of the service of global navigation satellite systems. This is due to their universalities. Gratitude to the up-to-date wireless data transfer solutions that can assure the near-real time geographical location detection of the respective moving object and individuals. Nowadays, these alternate services are widely used in many areas of public life i.e. fleet tracking or personal and property security. The proper way of integration into the state administrational technical support subsystem of these developed technologies and the implementation of the available services can significantly increase the effectiveness of the public duties’ performance, both in the area of public services and governmental organisations. These could contribute to the creation of the picture of “Good State” and to raise the standardised level of services provided to the citizens.

Examining Some Key Issues of the Maintenance Organisation from the Point of View of the Operator and the Manufacturer

The variable tracking systems for troops monitoring on field were popular for espionage in the 1980s and 1990s. Then they became essential materials for the action movies of the 21st century. Due to the rapid development of information technologies, the different navigation methods, systems and tools, this is now a 24/7 service and can be purchased by anyone to have detections and observations of the actions of vehicles, groups of people, individuals or even animals. From the number of variable options available for navigation, the applicable procedures are based on radio frequencies, even within that, those solutions that work in the frame of the service of global navigation satellite systems. This is due to their universalities. Gratitude to the up-to-date wireless data transfer solutions that can assure the near-real time geographical location detection of the respective moving object and individuals. Nowadays, these alternate services are widely used in many areas of public life i.e. fleet tracking or personal and property security. The proper way of integration into the state administrational technical support subsystem of these developed technologies and the implementation of the available services can significantly increase the effectiveness of the public duties’ performance, both in the area of public services and governmental organisations. These could contribute to the creation of the picture of “Good State” and to raise the standardised level of services provided to the citizens.