Robert Swiatlak, B. Tibken, Thomas Paradowski, Robert Dehnert
{"title":"An interval arithmetic approach for the estimation of the robust domain of attraction for nonlinear autonomous systems with nonlinear uncertainties","authors":"Robert Swiatlak, B. Tibken, Thomas Paradowski, Robert Dehnert","doi":"10.1109/ACC.2015.7171139","DOIUrl":"https://doi.org/10.1109/ACC.2015.7171139","url":null,"abstract":"This paper investigates an algorithm for the estimation of the robust domain of attraction (RDA) for nonlinear autonomous systems with uncertain parameters. Usually, an exact mathematical model for a system is assumed. In real systems, there are uncertainties caused by e. g. temperature drift or friction, which increases while lifetime. Furthermore, system parameters could be varied by the user. However, time-dependent parameters fluctuate in an known interval. Therefore, it is important to determine the domain of attraction for all configurations of the system. The presented method can estimate the RDA for systems with linear as well as nonlinear uncertainties. In this algorithm, interval arithmetic is used to determine successively the RDA by an inner and an outer bound. As a result, the algorithm delivers an enclosure of the Lyapunov function (LF) contour line c*.","PeriodicalId":223665,"journal":{"name":"2015 American Control Conference (ACC)","volume":"175 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115989830","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Bounding the effect of retroactivity in the presence of parameter uncertainty","authors":"Thomas P. Prescott, A. György","doi":"10.1109/ACC.2015.7171812","DOIUrl":"https://doi.org/10.1109/ACC.2015.7171812","url":null,"abstract":"As the number of synthetic genetic modules grows, the issue of reliably predicting their behavior upon interconnection becomes more pressing. The trajectory of an upstream module changes once connected to a downstream module due to retroactivity. Here, we employ dissipativity analysis to provide an upper bound on the L2 measure of this difference. To obtain this upper bound we formulate a Sum of Squares (SOS) optimization problem which we then solve using semi-definite programming. One particular strength of this approach is the ability to successfully handle parameter uncertainties while providing guaranteed upper bounds on the difference between the trajectories. We illustrate how to apply our method in the case of the most recurrent motif in gene networks.","PeriodicalId":223665,"journal":{"name":"2015 American Control Conference (ACC)","volume":"126 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116092027","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
G. Hilhorst, G. Pipeleers, W. Michiels, R. Oliveira, P. Peres, J. Swevers
{"title":"Reduced-order ℋ2/ℋ∞ control of discrete-time LPV systems with experimental validation on an overhead crane test setup","authors":"G. Hilhorst, G. Pipeleers, W. Michiels, R. Oliveira, P. Peres, J. Swevers","doi":"10.1109/ACC.2015.7170723","DOIUrl":"https://doi.org/10.1109/ACC.2015.7170723","url":null,"abstract":"This paper presents a numerically attractive approach to design reduced-order multi-objective ℋ<sub>2</sub>/ℋ<sub>∞</sub> controllers for discrete-time linear parameter-varying (LPV) systems. The proposed controller synthesis approach relies on an a priori computed polynomially parameter-dependent full-order LPV controller that stabilizes the LPV system for all possible parameter trajectories. This full-order controller is subsequently used in a sufficient linear matrix inequality (LMI) optimization problem for reduced-order ℋ<sub>2</sub>/ℋ<sub>∞</sub> LPV synthesis. Pólya relaxations are used to obtain tractable LMI formulations, and a simplicial subdivision of the parameter domain is applied to relieve the numerical burden. Experimental validations on a lab-scale overhead crane with varying cable length illustrate the practical viability of the approach.","PeriodicalId":223665,"journal":{"name":"2015 American Control Conference (ACC)","volume":"190 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116408546","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Path planning for information acquisition and evasion using marsupial vehicles","authors":"Jonathan C. Las Fargeas, P. Kabamba, A. Girard","doi":"10.1109/ACC.2015.7171910","DOIUrl":"https://doi.org/10.1109/ACC.2015.7171910","url":null,"abstract":"This paper considers a path planning problem with two marsupial vehicles (one carrier vehicle and one passenger vehicle that is deployed by the carrier vehicle) exploring a planar area. This work is motivated by multi-agent intelligence, surveillance, and reconnaissance missions in contested environments. The vehicles are heterogeneous, e.g., the carrier vehicle is faster than the passenger vehicle or the passenger vehicle possesses better sensors than the carrier vehicle. The vehicles are to gather a finite amount of information about an object of interest using their sensors while minimizing the likelihood of their detection by an opponent. Necessary conditions for optimal solutions are given and straight line travel for both vehicles is shown to be optimal. The results are illustrated in several simulation examples.","PeriodicalId":223665,"journal":{"name":"2015 American Control Conference (ACC)","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116435178","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Mirzaei, T. Göçmen, G. Giebel, P. Sørensen, N. K. Poulsen
{"title":"Turbine Control strategies for wind farm power optimization","authors":"M. Mirzaei, T. Göçmen, G. Giebel, P. Sørensen, N. K. Poulsen","doi":"10.1109/ACC.2015.7170979","DOIUrl":"https://doi.org/10.1109/ACC.2015.7170979","url":null,"abstract":"In recent decades there has been increasing interest in green energies, of which wind energy is the most important one. In order to improve the competitiveness of the wind power plants, there are ongoing researches to decrease cost per energy unit and increase the efficiency of wind turbines and wind farms. One way of achieving these goals is to optimize the power generated by a wind farm. One optimization method is to choose appropriate operating points for the individual wind turbines in the farm. We have made three models of a wind farm based on three difference control strategies. Basically, the control strategies determine the steady state operating points of the wind turbines. Except the control strategies of the individual wind turbines, the wind farm models are similar. Each model consists of a row of 5MW reference wind turbines. In the models we are able to optimize the generated power by changing the power reference of the individual wind turbines. We use the optimization setup to compare power production of the wind farm models. This paper shows that for the most frequent wind velocities (below and around the rated values), the generated powers of the wind farms are different. This means that choosing an appropriate control strategy for the individual wind turbines will result in an increased power production of the wind farm.","PeriodicalId":223665,"journal":{"name":"2015 American Control Conference (ACC)","volume":"120 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116572709","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Philip N. Sabes, Maria C. Dadarlat, J. E. O’Doherty
{"title":"A learning-based approach to artificial sensory feedback","authors":"Philip N. Sabes, Maria C. Dadarlat, J. E. O’Doherty","doi":"10.1109/ACC.2015.7171917","DOIUrl":"https://doi.org/10.1109/ACC.2015.7171917","url":null,"abstract":"The planning and control of even simple movements, such as reaching for an object, rely on somatosensory feedback of the state of the limb. Such feedback will be equally important for naturalistic control of neuro-prosthetic devices. For this reason, there has been considerable interest in the development of systems for artificial somatosensory feedback, in particular using electrical microstimulation of the brain. Much of this work has focused on creating “biomimetic” patterns of neural activation, i.e., trying replicate natural sensory-drive activity, however the challenges for this approach remain significant. We have developed a complementary approach, focusing instead on the brain's natural ability to to learn. In particular, we learn to combine somatosensory and visual feedback of the limb in a statistically optimal fashion and to recalibrate the two senses when they come out of alignment. Moreover, computational work from our lab shows that these learning processes can be achieved by simple algorithms, driven only by spatiotemporal correlations between the two sensory signals. We have tested this idea in a demonstration of a novel, learning-based approach to artificial motor feedback. Animals were trained to perform a reaching task under the guidance of visual feedback. They were then exposed to a novel, artificial feedback signal in the form of a non-biomimetic pattern of multielectrode intracortical microstimulation (ICMS). After training with correlated visual and ICMS feedback, the animals were able to perform precise movements with the artificial signal alone. Furthermore, they combine the ICMS signal with vision in a statistically optimal fashion, as would be done for two natural stimuli. This result serves as a proof-of-concept for a learning-based approach to artificial feedback with brain-machine interfaces.","PeriodicalId":223665,"journal":{"name":"2015 American Control Conference (ACC)","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122304143","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A case study in experimentally-infused plant and controller optimization for airborne wind energy systems","authors":"N. Deodhar, C. Vermillion, P. Tkacik","doi":"10.1109/ACC.2015.7171087","DOIUrl":"https://doi.org/10.1109/ACC.2015.7171087","url":null,"abstract":"This paper presents a combined plant and controller optimization process for airborne wind energy systems (AWEs) that fuses numerical optimization with lab-scale experimental results. The methodology introduced in this paper, referred to as experimentally-infused optimization, addresses several challenges faced by AWE system designers, including a strong coupling between the controller and plant design, significant modeling uncertainties (which require the use of experiments), and high costs associated with full-scale experimental prototypes. This paper presents an initial case study of the proposed experimentally-infused optimization, where experiments were conducted on a 1/100th-scale model of Altaeros Buoyant Air Turbine (BAT), which was tethered and flown in the University of North Carolina at Charlotte 1m × 1m water channel. The lab-scale experimental platform reduced the cost of evaluating flight dynamics and control by more than two orders of magnitude, while resulting in substantially improved flight performance, quantified by a 15.2 percent improvement in an objective function value, as compared to a purely numerical optimization.","PeriodicalId":223665,"journal":{"name":"2015 American Control Conference (ACC)","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122318266","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Finite-time convergence policies in state-dependent social networks","authors":"D. Silvestre, P. Rosa, J. Hespanha, C. Silvestre","doi":"10.1109/ACC.2015.7170870","DOIUrl":"https://doi.org/10.1109/ACC.2015.7170870","url":null,"abstract":"This paper addresses the problem of finite-time convergence in a social network for a political party or an association, modeled as a distributed iterative system with a graph dynamics chosen to mimic how people interact. It is firstly shown that, in this setting, finite-time convergence is achieved only when nodes form a complete network, and that contacting with agents with distinct opinions reduces to a half the required interconnections. Two novel strategies are presented that enable finite-time convergence, even for the case where each node only contacts the two closest neighbors. These strategies are of prime importance, for instance, in a company environment where agents can be motivated to reach faster conclusions. The performance of the proposed policies is assessed through simulation, illustrating, in particular the finite-time convergence property.","PeriodicalId":223665,"journal":{"name":"2015 American Control Conference (ACC)","volume":"156 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122448349","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Multiple-dynamic-scaling output-feedback control for uncertain strict-feedback-like systems with input unmodeled dynamics","authors":"P. Krishnamurthy, F. Khorrami","doi":"10.1109/ACC.2015.7171140","DOIUrl":"https://doi.org/10.1109/ACC.2015.7171140","url":null,"abstract":"A general class of uncertain strict-feedback-like nonlinear systems with dynamic input nonlinearities is considered. The addressed nonlinear system structure can be viewed as a nominal system of strict-feedback-like form with its input signal given by an uncertain nonlinear function coupled with an uncertain nonlinear time-varying input unmodeled dynamics. The proposed controller is based on a scaling-based redesign of the dual dynamic high-gain scaling based output-feedback control design for strict-feedback-like systems. The scaling-based redesign introduces a dynamic state extension and an additional dynamic scaling based on a singular-perturbation-like structure to address the nonlinear uncertain dynamic input perturbation. The proposed approach provides a globally stabilizing output-feedback control design that is robust to the uncertain input unmodeled dynamics and functional and parameteric uncertainties allowed in the system structure.","PeriodicalId":223665,"journal":{"name":"2015 American Control Conference (ACC)","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122941983","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Autonomous vehicle control for emergency maneuvers: The effect of topography","authors":"John K. Subosits, J. C. Gerdes","doi":"10.1109/ACC.2015.7170930","DOIUrl":"https://doi.org/10.1109/ACC.2015.7170930","url":null,"abstract":"When attempting to drive collision-free paths in emergency situations, automobiles are limited by the amount of force their tires can produce through friction. A road's topography affects the tire forces, so the ability of an autonomous vehicle to follow a desired path depends on the shape of the path in three, not two, dimensions. In this paper, a model that captures the effects of road topography on tire forces is derived and used to compute the speeds at which a given path can be followed. Experimental evidence is used to support the conclusion that accounting for topography, particularly the vertical curvature of the road, is critical for good path tracking performance even with a conservative estimate of maximum friction.","PeriodicalId":223665,"journal":{"name":"2015 American Control Conference (ACC)","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122513029","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}