Pub Date : 2009-06-24DOI: 10.1109/MED.2009.5164579
M. Vaccarini, S. Longhi
Traditional ocean research and exploration usually require a lot of time, funds and, in general, resources. In the last years, mainly thanks to the GPS technology, unmanned small vehicles have been proposed for marine exploration and investigation. In this paper, a cooperation scheme (either for surface and underwater vehicles) is outlined for a multi-robot framework with a certain mission. The objective is translated into a formation control problem and the coordination is achieved through underwater sonar communication. A real-time implementable formation control strategy based on Networked Decentralized MPC is presented that drive each single vehicle. MPC allows to take into account for constraints, nonlinearities and exchanged information about future behaviours of the single agents. The decentralized strategy makes use of either local and received information for computing the best behaviour that optimises some objective function. A reconfigurable hierarchical structure is assumed for managing the formation. The real-time implementability is achieved using Multiplexed MPC and/or stochastic optimization algorithms for reducing computation times. Simulation results are provided for comparing the presented algorithms.
{"title":"Formation control of marine veihicles via real-time Networked Decentralized MPC","authors":"M. Vaccarini, S. Longhi","doi":"10.1109/MED.2009.5164579","DOIUrl":"https://doi.org/10.1109/MED.2009.5164579","url":null,"abstract":"Traditional ocean research and exploration usually require a lot of time, funds and, in general, resources. In the last years, mainly thanks to the GPS technology, unmanned small vehicles have been proposed for marine exploration and investigation. In this paper, a cooperation scheme (either for surface and underwater vehicles) is outlined for a multi-robot framework with a certain mission. The objective is translated into a formation control problem and the coordination is achieved through underwater sonar communication. A real-time implementable formation control strategy based on Networked Decentralized MPC is presented that drive each single vehicle. MPC allows to take into account for constraints, nonlinearities and exchanged information about future behaviours of the single agents. The decentralized strategy makes use of either local and received information for computing the best behaviour that optimises some objective function. A reconfigurable hierarchical structure is assumed for managing the formation. The real-time implementability is achieved using Multiplexed MPC and/or stochastic optimization algorithms for reducing computation times. Simulation results are provided for comparing the presented algorithms.","PeriodicalId":422386,"journal":{"name":"2009 17th Mediterranean Conference on Control and Automation","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127548311","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}
Pub Date : 2009-06-24DOI: 10.1109/MED.2009.5164714
I. Raptis, K. Valavanis, W. Moreno
This paper presents a backstepping control design for small scale helicopters. The objective is for the helicopter to autonomously track predefined position and yaw trajectories. The position reference trajectories are arbitrary, possibly aggressive, with some constraints in their higher order time derivatives. The main idea of the algorithm is to control the direction and magnitude of the thrust vector appropriately in order to stabilize the position dynamics. In contrast with most control schemes that use Euler angles or quaternions for the control of the attitude dynamics, this design use the elements of the rotation matrix. The intermediate pseudo controls related with the directional dynamics are enhanced with terms that guarantee that the helicopter will not overturn while tracking the position reference signals.
{"title":"Nonlinear backstepping control design for miniature helicopters using the rotation matrix","authors":"I. Raptis, K. Valavanis, W. Moreno","doi":"10.1109/MED.2009.5164714","DOIUrl":"https://doi.org/10.1109/MED.2009.5164714","url":null,"abstract":"This paper presents a backstepping control design for small scale helicopters. The objective is for the helicopter to autonomously track predefined position and yaw trajectories. The position reference trajectories are arbitrary, possibly aggressive, with some constraints in their higher order time derivatives. The main idea of the algorithm is to control the direction and magnitude of the thrust vector appropriately in order to stabilize the position dynamics. In contrast with most control schemes that use Euler angles or quaternions for the control of the attitude dynamics, this design use the elements of the rotation matrix. The intermediate pseudo controls related with the directional dynamics are enhanced with terms that guarantee that the helicopter will not overturn while tracking the position reference signals.","PeriodicalId":422386,"journal":{"name":"2009 17th Mediterranean Conference on Control and Automation","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131027538","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}
Pub Date : 2009-06-24DOI: 10.1109/MED.2009.5164630
J. Stergiopoulos, G. Konstantopoulos, A. Tzes
The aim of this paper is the presentation of an adaptive input shaping technique suitable for overhead cranes with hoisting mechanism. The main goal is the minimization of the remaining oscillations when the motion of the trolley and the hoisting of the load are performed simultaneously. While standard input shaping theory can be applied in its standard form in classical cranes, the shaper configuration when the load is hoisted is not profound. The adaptive version proposed calculates the parameters of the shaper online depending on the updated linearized model and the current rope length. Experimental results show the benefits of the proposed controller contrary to standard input shaping and to unshaped responses.
{"title":"Experimental verification of an adaptive input shaping scheme for hoisting cranes","authors":"J. Stergiopoulos, G. Konstantopoulos, A. Tzes","doi":"10.1109/MED.2009.5164630","DOIUrl":"https://doi.org/10.1109/MED.2009.5164630","url":null,"abstract":"The aim of this paper is the presentation of an adaptive input shaping technique suitable for overhead cranes with hoisting mechanism. The main goal is the minimization of the remaining oscillations when the motion of the trolley and the hoisting of the load are performed simultaneously. While standard input shaping theory can be applied in its standard form in classical cranes, the shaper configuration when the load is hoisted is not profound. The adaptive version proposed calculates the parameters of the shaper online depending on the updated linearized model and the current rope length. Experimental results show the benefits of the proposed controller contrary to standard input shaping and to unshaped responses.","PeriodicalId":422386,"journal":{"name":"2009 17th Mediterranean Conference on Control and Automation","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126903115","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}
Pub Date : 2009-06-24DOI: 10.1109/MED.2009.5164596
J. Georges, D. Theilliol, J. Ponsart, C. Aubrun
This paper presents a FTC approach based on sensor masking principle in the special case of control system integrating a wireless sensor network. In the presence of sensor faults, the faulty measurements corrupt directly the behaviour of the closed-loop systems. With wireless transmission, packet losses are acting as additional sensor faults. Since the controller aims at cancelling the error between the measurement and its reference input, the real outputs will in such networked control system deviate from the desired value and may drive the system to its physical limitations or even to instability. The proposed method makes possible the faults compensation based on a classical Interacting Multiple Model developed in the framework of multiple sensors failures. The IMM involved in Networked Control system provides simultaneously on-line packet losses detection, and isolation and also a suitable state estimation. Based on particular knowledge on packet losses, sensor fault-tolerant controls are obtained by computing a new control law using a fault-free estimation of the faulty element to avoid faults to develop into failures and to minimise the effects on the system performance and safety.
{"title":"Networked Control system with intermittent observations: FDI/FTC design based on Interacting Multiple Model approach","authors":"J. Georges, D. Theilliol, J. Ponsart, C. Aubrun","doi":"10.1109/MED.2009.5164596","DOIUrl":"https://doi.org/10.1109/MED.2009.5164596","url":null,"abstract":"This paper presents a FTC approach based on sensor masking principle in the special case of control system integrating a wireless sensor network. In the presence of sensor faults, the faulty measurements corrupt directly the behaviour of the closed-loop systems. With wireless transmission, packet losses are acting as additional sensor faults. Since the controller aims at cancelling the error between the measurement and its reference input, the real outputs will in such networked control system deviate from the desired value and may drive the system to its physical limitations or even to instability. The proposed method makes possible the faults compensation based on a classical Interacting Multiple Model developed in the framework of multiple sensors failures. The IMM involved in Networked Control system provides simultaneously on-line packet losses detection, and isolation and also a suitable state estimation. Based on particular knowledge on packet losses, sensor fault-tolerant controls are obtained by computing a new control law using a fault-free estimation of the faulty element to avoid faults to develop into failures and to minimise the effects on the system performance and safety.","PeriodicalId":422386,"journal":{"name":"2009 17th Mediterranean Conference on Control and Automation","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128876140","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}
Pub Date : 2009-06-24DOI: 10.1109/MED.2009.5164631
M. Mirmomeni, C. Lucas, Babak Nadjar Araabi
several methods have been introduced for identification of nonlinear processes via locally or partially linear models. Unfortunately, most of these methods have a training phase which should be done offline. There are phenomena that possess time varying behavior. Furthermore, the amount, distribution and/or quality of measurement data that is available before the model is put to operation may be insufficient to build a model that would meet the specification. One of the most popular learning methods in nonlinear system identification is Locally Linear Model Tree (LoLiMoT) algorithm as an incremental learning method which needs to be carried out by an offline data set. This paper introduces a recursive version of this algorithm called Recursive Locally Linear Model Tree algorithm (RLoLiMoT) for time varying and online applications. The proposed method also eliminates some of the LoLiMoT restrictions in tuning premise parameters of the Locally Linear Models (LLMs). Two case studies are considered to test the performance of the proposed method. The results depict the power of the proposed method in online system identification of nonlinear time varying systems.
{"title":"Introducing recursive learning algorithm for system identification of nonlinear time varying processes","authors":"M. Mirmomeni, C. Lucas, Babak Nadjar Araabi","doi":"10.1109/MED.2009.5164631","DOIUrl":"https://doi.org/10.1109/MED.2009.5164631","url":null,"abstract":"several methods have been introduced for identification of nonlinear processes via locally or partially linear models. Unfortunately, most of these methods have a training phase which should be done offline. There are phenomena that possess time varying behavior. Furthermore, the amount, distribution and/or quality of measurement data that is available before the model is put to operation may be insufficient to build a model that would meet the specification. One of the most popular learning methods in nonlinear system identification is Locally Linear Model Tree (LoLiMoT) algorithm as an incremental learning method which needs to be carried out by an offline data set. This paper introduces a recursive version of this algorithm called Recursive Locally Linear Model Tree algorithm (RLoLiMoT) for time varying and online applications. The proposed method also eliminates some of the LoLiMoT restrictions in tuning premise parameters of the Locally Linear Models (LLMs). Two case studies are considered to test the performance of the proposed method. The results depict the power of the proposed method in online system identification of nonlinear time varying systems.","PeriodicalId":422386,"journal":{"name":"2009 17th Mediterranean Conference on Control and Automation","volume":"49 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120890679","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}
Pub Date : 2009-06-24DOI: 10.1109/MED.2009.5164732
W. Griggs, C. King, R. Shorten, O. Mason, K. Wulff
The question of existence of joint quadratic Lyapunov functions (QLFs) for state-dependent, switched dynamical systems is given a preliminary geometrical treatment in this paper. The joint QLF problem for a switched system and a collection of regions defined by state vectors that determine when switching occurs consists of finding nonempty intersections of convex sets of QLFs. The existence of a joint QLF guarantees switched system stability. Necessary and sufficient conditions for the existence of a joint QLF are obtained for a two-dimensional problem.
{"title":"A geometrical treatment for obtaining necessary and sufficient conditions for joint quadratic Lyapunov function existence for state-dependent, switched systems: A two-dimensional case","authors":"W. Griggs, C. King, R. Shorten, O. Mason, K. Wulff","doi":"10.1109/MED.2009.5164732","DOIUrl":"https://doi.org/10.1109/MED.2009.5164732","url":null,"abstract":"The question of existence of joint quadratic Lyapunov functions (QLFs) for state-dependent, switched dynamical systems is given a preliminary geometrical treatment in this paper. The joint QLF problem for a switched system and a collection of regions defined by state vectors that determine when switching occurs consists of finding nonempty intersections of convex sets of QLFs. The existence of a joint QLF guarantees switched system stability. Necessary and sufficient conditions for the existence of a joint QLF are obtained for a two-dimensional problem.","PeriodicalId":422386,"journal":{"name":"2009 17th Mediterranean Conference on Control and Automation","volume":"144 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116081312","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}
Pub Date : 2009-06-24DOI: 10.1109/MED.2009.5164668
Grant Miller, S. Atev, N. Papanikolopoulos
Static occlusions are a common impediment to successful object tracking in many realistic scenes. Knowledge about the locations of occlusions in the field of view of video cameras can allow tracking algorithms to successfully handle occlusion events. We present a simple and efficient rule-based method for finding large, rigid occluders in a scene by analysis of images from a single camera. Pixels along occlusion edges are identified through specific spatiotemporal patterns occurring in the binary foreground segmentation masks obtained from the input video. The final output of our algorithm is a binary mask indicating the locations of static occluders in the scene. We present experimental results from several outdoor scenes and compare the performance of the algorithm with a previously proposed method.
{"title":"Detecting static occlusion edges using foreground patterns","authors":"Grant Miller, S. Atev, N. Papanikolopoulos","doi":"10.1109/MED.2009.5164668","DOIUrl":"https://doi.org/10.1109/MED.2009.5164668","url":null,"abstract":"Static occlusions are a common impediment to successful object tracking in many realistic scenes. Knowledge about the locations of occlusions in the field of view of video cameras can allow tracking algorithms to successfully handle occlusion events. We present a simple and efficient rule-based method for finding large, rigid occluders in a scene by analysis of images from a single camera. Pixels along occlusion edges are identified through specific spatiotemporal patterns occurring in the binary foreground segmentation masks obtained from the input video. The final output of our algorithm is a binary mask indicating the locations of static occluders in the scene. We present experimental results from several outdoor scenes and compare the performance of the algorithm with a previously proposed method.","PeriodicalId":422386,"journal":{"name":"2009 17th Mediterranean Conference on Control and Automation","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116123726","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}
Pub Date : 2009-06-24DOI: 10.1109/MED.2009.5164730
N. Mohammadzadeh, M. Mola, R. Amirifar
The control of an industrial manipulator Arm with high accuracy in the presence of multi-model is a challenging control problem. In this paper, it is shown that based on identified models a robust linear controller can be designed using the combined pole placement method with sensitivity function shaping in the frequency domain via performance limitation for example modulus margin. This controller provides satisfactory performance for a large range of load variations.
{"title":"Robust control of manipulator arm using combined shame via performance limitation","authors":"N. Mohammadzadeh, M. Mola, R. Amirifar","doi":"10.1109/MED.2009.5164730","DOIUrl":"https://doi.org/10.1109/MED.2009.5164730","url":null,"abstract":"The control of an industrial manipulator Arm with high accuracy in the presence of multi-model is a challenging control problem. In this paper, it is shown that based on identified models a robust linear controller can be designed using the combined pole placement method with sensitivity function shaping in the frequency domain via performance limitation for example modulus margin. This controller provides satisfactory performance for a large range of load variations.","PeriodicalId":422386,"journal":{"name":"2009 17th Mediterranean Conference on Control and Automation","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115389264","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}
Pub Date : 2009-06-24DOI: 10.1109/MED.2009.5164689
Giorgos Altanis, N. Maratos
This work studies the problem of monitoring and avoiding fold (saddle-node) bifurcations of equilibria without solving any difficult optimization problems, such as the closest bifurcation problem. New scalar indices are proposed to monitor the proximity to fold bifurcations. These indices are based on the QR factorization of the Jacobian matrix, and they are directionally differentiable in the interior of the feasibility boundary. This allows us to compute steepest descent directions in the uncontrollable parameter space and steepest ascent directions in the controllable parameter space. The former are used to estimate the distance to the feasibility boundary, while the latter are used by a simple algorithm which designs the controllable parameters in a way that the proximity indices maintain values above a certain threshold, thus avoiding the feasibility boundary. One of the proposed indices is asymptotically linear with respect to the distance to the bifurcation value being approached, resulting in accurate estimates of the distance to the bifurcation.
{"title":"Avoiding fold bifurcations with the help of new proximity indices","authors":"Giorgos Altanis, N. Maratos","doi":"10.1109/MED.2009.5164689","DOIUrl":"https://doi.org/10.1109/MED.2009.5164689","url":null,"abstract":"This work studies the problem of monitoring and avoiding fold (saddle-node) bifurcations of equilibria without solving any difficult optimization problems, such as the closest bifurcation problem. New scalar indices are proposed to monitor the proximity to fold bifurcations. These indices are based on the QR factorization of the Jacobian matrix, and they are directionally differentiable in the interior of the feasibility boundary. This allows us to compute steepest descent directions in the uncontrollable parameter space and steepest ascent directions in the controllable parameter space. The former are used to estimate the distance to the feasibility boundary, while the latter are used by a simple algorithm which designs the controllable parameters in a way that the proximity indices maintain values above a certain threshold, thus avoiding the feasibility boundary. One of the proposed indices is asymptotically linear with respect to the distance to the bifurcation value being approached, resulting in accurate estimates of the distance to the bifurcation.","PeriodicalId":422386,"journal":{"name":"2009 17th Mediterranean Conference on Control and Automation","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115945482","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}
Pub Date : 2009-06-24DOI: 10.1109/MED.2009.5164759
N. Talebi, M. Sadrnia, S. Rafiei
Power inverters are used to acquire an ac output voltage from a dc power supply. The parallel connection of inverters results in several advantages, like improvement of the system reliability and increasing of the power capacity. The control problem for parallel-connected inverters is proper voltage regulation and equal current distribution. In this paper, a characteristic loci based compensator (Approximate commutative compensator) is used to obtain design objectives. In order to compare results, Hæ and LQG/LTR controllers, are also implemented on parallel inverters. Simulation results of the single-module, two-module and three-module inverter systems with different kinds of loads and parametric uncertainties, have demonstrated the feasibility of the proposed control scheme in proper voltage regulation and equal current distribution.
{"title":"Current and voltage control of paralleled multi-module inverter systems","authors":"N. Talebi, M. Sadrnia, S. Rafiei","doi":"10.1109/MED.2009.5164759","DOIUrl":"https://doi.org/10.1109/MED.2009.5164759","url":null,"abstract":"Power inverters are used to acquire an ac output voltage from a dc power supply. The parallel connection of inverters results in several advantages, like improvement of the system reliability and increasing of the power capacity. The control problem for parallel-connected inverters is proper voltage regulation and equal current distribution. In this paper, a characteristic loci based compensator (Approximate commutative compensator) is used to obtain design objectives. In order to compare results, Hæ and LQG/LTR controllers, are also implemented on parallel inverters. Simulation results of the single-module, two-module and three-module inverter systems with different kinds of loads and parametric uncertainties, have demonstrated the feasibility of the proposed control scheme in proper voltage regulation and equal current distribution.","PeriodicalId":422386,"journal":{"name":"2009 17th Mediterranean Conference on Control and Automation","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121180590","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：