{"title":"Dominant modes estimation using SCUSUM method along with SSI","authors":"V. ShashankS., M. R. Mariya, M. Mamta","doi":"10.1109/MED54222.2022.9837208","DOIUrl":"https://doi.org/10.1109/MED54222.2022.9837208","url":null,"abstract":"Low-frequency oscillations (LFOs) in the power system have emerged as a significant possible cause of abrupt wide-area blackouts in several parts of the world. As consumer demand grows, so does the insecurity of the operational stability points of power systems as a result of unforeseen events such as connection and disconnection of loads, generators, or inter-area power networks. Although the stochastic subspace identification performed well in identifying certain LFO modes, it gives inaccurate results due to incorrect model order estimates. Incorrect estimation of model order results in the inclusion of trivial modes to essential subspace modes of a power system. The Sequential Cumulative Sum (SCUSUM) approach of order estimation detects changes in the mean with respect to the eigenvalues. This paper proposes the use of the SCUSUM method instead of estimating using the singular value decomposition of the weighted projection matrix in Stochastic Subspace Identification.","PeriodicalId":354557,"journal":{"name":"2022 30th Mediterranean Conference on Control and Automation (MED)","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124117187","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}
I. Rachid, T. Zoulagh, F. Tadeo, Hassnae Merzouki, E. Tissir
{"title":"Finite Frequency H∞ Control of Two-Dimensional Continuous Takagi-Sugeno Systems","authors":"I. Rachid, T. Zoulagh, F. Tadeo, Hassnae Merzouki, E. Tissir","doi":"10.1109/MED54222.2022.9837251","DOIUrl":"https://doi.org/10.1109/MED54222.2022.9837251","url":null,"abstract":"This paper solves a state feedback H∞ control issue for two-dimensional (2D) nonlinear continuous systems described by Takagi-Sugeno (T-S) fuzzy model by using a finite frequency (FF) approach. In particular, a Roesser model is investigated by employing the Generalized Kalman Yakubovich Popov (GKYP) lemma. New conditions guaranteeing the FF H∞ control and the bounded-input-bounded-output (BIBO) stability of the closed-loop system are established in terms of Linear Matrix Inequalities (LMIs). These stipulations extend minimal conservative results not only by getting the controller gain, but also in terms of H∞ norm and closed-loop states’ convergence when compared with the entire frequency (EF) design and the uncontrolled states. To exhibit the superiority of the submitted strategy, an implementation to a simulated system is thus presented.","PeriodicalId":354557,"journal":{"name":"2022 30th Mediterranean Conference on Control and Automation (MED)","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127828779","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":"Precise Motion Control of Autonomous Robots","authors":"B. Novakovic, D. Majetic, J. Kasać, D. Brezak","doi":"10.1109/MED54222.2022.9837200","DOIUrl":"https://doi.org/10.1109/MED54222.2022.9837200","url":null,"abstract":"In the case of the control synthesis of the autonomous robot precise motions in production processes, or autonomous micro/nano robot motions in drug delivery, one have to use a related Hamiltonian. It is assumed that the autonomous robot (or micro/nano robot) motions are in a multipotential field. In order to simplify control process, the concept of the external linearization is used. In that case, the nonlinear control in the closed loop with the nonlinear canonical differential equations of the autonomous robot (or micro/nano robot) motion is resulting in the linear behavior of the whole system. Therefore, the linear control algorithms can be applied. This is the main contribution of the paper. The control process is calculated in the combination of the electromagnetic and gravitational fields. In that case, the autonomous robot (or micro/nano robot) moves towards a target with limited information about the environment. The main point of these algorithms is to minimize the use of the outer perimeter of an obstacle, which also minimizes total path length taken by the autonomous robot (or micro/nano robot).","PeriodicalId":354557,"journal":{"name":"2022 30th Mediterranean Conference on Control and Automation (MED)","volume":"17 3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129011777","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}
Sotirios Spanogianopoulos, K. Sirlantzis, Kenan Ahiska
{"title":"RRT-based Path Planning for Car-Like Vehicles with Nonholonomic Constraints","authors":"Sotirios Spanogianopoulos, K. Sirlantzis, Kenan Ahiska","doi":"10.1109/MED54222.2022.9837136","DOIUrl":"https://doi.org/10.1109/MED54222.2022.9837136","url":null,"abstract":"In this paper, for car-like mobile robots, a novel path planning algorithm is proposed. The algorithm is based on rapidly-exploring random trees (RRT) with fixed nodes (RRT*FN). An improvement on the RRT*FN is proposed to abide by the non-holonomic motion constraints and RRT*FN non-holonomic (RRT*FN-NH) is introduced. The new path planning algorithm handles the non-holonomic constraints as well as the constraints on the velocity and acceleration of the vehicle. The performance of the proposed algorithm RRT*FN-NH is tested on two maps obtained from Google maps at three different speed profiles.","PeriodicalId":354557,"journal":{"name":"2022 30th Mediterranean Conference on Control and Automation (MED)","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122204956","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 Hierarchical Dual Decomposition-based Distributed Optimization Algorithm combining Quasi-Newton Steps and Bundle Methods","authors":"V. Yfantis, M. Ruskowski","doi":"10.1109/MED54222.2022.9837219","DOIUrl":"https://doi.org/10.1109/MED54222.2022.9837219","url":null,"abstract":"This paper presents a hierarchical distributed optimization algorithm based on quasi-Newton update steps. Separable convex optimization problems are decoupled through dual decomposition and solved in a distributed fashion by coordinating the solutions of the subproblems through dual variables. The proposed algorithm updates the dual variables by approximating the Hessian of the dual function through collected subgradient information, analogously to quasi-Newton methods. As the dual maximization problem is generally nonsmooth, a smooth approximation might show poor performance. To this end cutting planes, analogous to bundle methods, are constructed that take the nonsmoothness of the dual function into account and lead to a better convergence behavior near the optimum. The proposed algorithm is evaluated on a large set of benchmark problems and compared to the subgradient method and to the bundle trust method for nonsmooth optimization.","PeriodicalId":354557,"journal":{"name":"2022 30th Mediterranean Conference on Control and Automation (MED)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130762804","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}
Evangelos Vlachos, E. Spyrou, C. Stylios, K. Berberidis
{"title":"Optimal MmWave Sensor Selection for Bearing-Only Localization in Smart Environments","authors":"Evangelos Vlachos, E. Spyrou, C. Stylios, K. Berberidis","doi":"10.1109/MED54222.2022.9837261","DOIUrl":"https://doi.org/10.1109/MED54222.2022.9837261","url":null,"abstract":"Nowdays, millimeter wave (mmWave) direction sensors are being used increasingly as general-purpose radars, since they can provide high-level of accuracy for a variety of situations at low-cost. Via mutliple mmWave sensors, bearing estimation can be derived to track the position of a target, while in smart environments several sensors can be deployed. In this work, we provide an optimal sensor selection technique, for choosing which sensors to activate for bearing estimation and which not. The proposed approach is decomposed into training phase, where sensor selection is performed, and operational phase, where bearing estimation is obtained. Via simulation results we evaluate the proposed approach compared with the conventional methodology of utilizing all available data streams.","PeriodicalId":354557,"journal":{"name":"2022 30th Mediterranean Conference on Control and Automation (MED)","volume":"117 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116582164","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}
A. Agrawal, Dhruv Agarwal, Mehul Arora, Ritik Mahajan, Shivansh Beohar, Lhilo Kenye, R. Kala
{"title":"SLAM and Map Learning using Hybrid Semantic Graph Optimization *","authors":"A. Agrawal, Dhruv Agarwal, Mehul Arora, Ritik Mahajan, Shivansh Beohar, Lhilo Kenye, R. Kala","doi":"10.1109/MED54222.2022.9837164","DOIUrl":"https://doi.org/10.1109/MED54222.2022.9837164","url":null,"abstract":"Visual Simultaneous Localization and Mapping using budget-grade cameras only faces the challenges of continuous drifts that accumulate with time. While loop closure techniques mitigate the effects, they are applicable only when the robot completes a loop, which is a rarity in everyday navigation. The motion blur and smaller resolution of budget cameras further reduce the accuracy of SLAM. In this paper, we aim to solve the problem of active drift correction for a low-cost robot to solve autonomous navigation using the semantic map. Semantic maps have been used previously for re-localization but are useful only when the semantic maps themselves are highly accurate which is not realizable for budget robots. The semantic maps also face problems of correspondence matching in areas rich with recurrent semantics. To alleviate the same effects, the robot performs SLAM using a hybrid graph optimization consisting of semantic points whose pose is obtained from the semantic map database, and the non-semantic point features. The semantic map corrects for the drift, while the non-semantic features apply local smoothing that helps in mitigating the errors of the semantic map. They also apply robustness against errors in correspondence matching. The semantic graph may itself have errors, which are hence learned with time as the robot navigates. The robot adds new semantic objects into the database if it observes them, while the robot also mends the position based on the new observations. The initial semantic map is made using images captured by a camera on a few known poses, based on which it adds the observed semantics.","PeriodicalId":354557,"journal":{"name":"2022 30th Mediterranean Conference on Control and Automation (MED)","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116950419","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}
Achilleas Santi Seisa, Gerasimos Damigos, S. Satpute, A. Koval, G. Nikolakopoulos
{"title":"Edge Computing Architectures for Enabling the Realisation of the Next Generation Robotic Systems","authors":"Achilleas Santi Seisa, Gerasimos Damigos, S. Satpute, A. Koval, G. Nikolakopoulos","doi":"10.1109/MED54222.2022.9837289","DOIUrl":"https://doi.org/10.1109/MED54222.2022.9837289","url":null,"abstract":"Edge Computing is a promising technology to provide new capabilities in technological fields that require instantaneous data processing. Researchers in areas such as machine and deep learning use extensively edge and cloud computing for their applications, mainly due to the significant computational and storage resources that they provide. Currently, Robotics is seeking to take advantage of these capabilities as well, and with the development of 5G networks, some existing limitations in the field can be overcome. In this context, it is important to know how to utilize the emerging edge architectures, what types of edge architectures and platforms exist today and which of them can and should be used based on each robotic application. In general, Edge platforms can be implemented and used differently, especially since there are several providers offering more or less the same set of services with some essential differences. Thus, this study addresses these discussions for those who work in the development of the next generation robotic systems and will help to understand the advantages and disadvantages of each edge computing architecture in order to choose wisely the right one for each application.","PeriodicalId":354557,"journal":{"name":"2022 30th Mediterranean Conference on Control and Automation (MED)","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131230088","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":"Attack-Resilient Multi-Agent Flocking Control Using Graph Neural Networks","authors":"C. Bhowmick, Mudassir Shabbir, X. Koutsoukos","doi":"10.1109/MED54222.2022.9837237","DOIUrl":"https://doi.org/10.1109/MED54222.2022.9837237","url":null,"abstract":"Flocking control of a group of mobile agents has been recently investigated using Graph Convolution Networks (GCNs). The design relies on training using a centralized controller but the resulting GCN controller is based on communication between the agents. The agents receive sensor measurements which are incorporated into the states and shared between the neighbors. However, the paradigm is prone to adversarial attacks. In this paper, we consider the problem of designing GCN-based distributed flocking control that is resilient to attacks on the communicated information. We consider an attack model that is used to compromise the inter-agent communication and may inject arbitrary signals. Our control design uses a coordinate-wise median-based aggregation function. It is shown that the GCN-based controller using the proposed aggregation method is resilient against attacks on the communication between the agents, whereas the typical average-based aggregation fails to maintain the flock structure. Robustness analysis is performed to show that the proposed method is resilient whenever a majority of the agents in the neighborhood can be trusted. Simulation results and analysis are presented that validate the merits of the proposed approach.","PeriodicalId":354557,"journal":{"name":"2022 30th Mediterranean Conference on Control and Automation (MED)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131334551","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":"PWA-CTM: An Extended Cell-Transmission Model based on Piecewise Affine Approximation of the Fundamental Diagram","authors":"F. Alimardani, J. Baras","doi":"10.1109/MED54222.2022.9837131","DOIUrl":"https://doi.org/10.1109/MED54222.2022.9837131","url":null,"abstract":"Throughout the past decades, many different versions of the widely used first-order Cell-Transmission Model (CTM) have been proposed for optimal traffic control. Highway traffic management techniques such as Ramp Metering (RM) are typically designed based on an optimization problem with nonlinear constraints originating in the flow-density relation of the Fundamental Diagram (FD). Most of the extended CTM versions are based on the trapezoidal approximation of the flow-density relation of the Fundamental Diagram (FD) in an attempt to simplify the optimization problem. However, this relation is naturally nonlinear, and crude approximations can greatly impact the efficiency of the optimization solution. In this study, we propose a class of extended CTMs that are based on piecewise affine approximations of the flow-density relation such that (a) the integrated squared error with respect to the true relation is greatly reduced in comparison to the trapezoidal approximation, and (b) the optimization problem remains tractable for real-time application of ramp metering optimal controllers. A two-step identification method is used to approximate the FD with piecewise affine functions resulting in what we refer to as PWA-CTMs. The proposed models are evaluated by the performance of the optimal ramp metering controllers, e.g. using the widely used PI-ALINEA approach, in complex highway traffic networks. Simulation results show that the optimization problems based on the PWA-CTMs require less computation time compared to other CTM extensions while achieving higher accuracy of the flow and density evolution. Hence, the proposed PWA-CTMs constitute one of the best approximation approaches for first-order traffic flow models that can be used in more general and challenging modeling and control applications.","PeriodicalId":354557,"journal":{"name":"2022 30th Mediterranean Conference on Control and Automation (MED)","volume":"62 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132234245","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}