This book is the final report of the action COST TU0702 Real-time monitoring, surveillance and co... more This book is the final report of the action COST TU0702 Real-time monitoring, surveillance and control or road networks under adverse weather conditions. This Action was initiated with the main objectives of better understanding impacts of adverse weather on freeways, motorways, or urban traffic operations and developing, promoting and implementing strategies and tools to mitigate those impacts. This advanced interdisciplinary report is the second scientific report of TU0702 which covers all important topics related to adverse weather impact on transport networks, i.e. pavement surface conditions, traffic modeling for weather-dependent control applications, weather modeling and traffic management strategies during adverse weather conditions. It provides a comprehensive analysis on how adverse weather impacts transport infrastructure and users behaviors, and how to manage a safer and more productive road networks under these inclement weather conditions. It proceeds to the integration of weather into traffic modeling tools. It includes an extensive analysis on weather-sensitive traffic management tools, exemplified in terms of state of the art best practices. Finally, recommendations are provided on how road authorities can implement in an efficient manner weather sensitive-traffic management strategies for improved traffic safety. The TU0702 experts, through a consensus-building process, have identified major challenges and knowledge gaps that require major research efforts towards a more efficient weather-sensitive traffic management and sustainable network efficiency for enhanced safety and resilience.
This paper deals with the application of an anticipating and coordinating feedback control scheme... more This paper deals with the application of an anticipating and coordinating feedback control scheme in order to mitigate the long-term voltage instability of multi-area power systems. Each local area is uniquely controlled by a control agent (CA) selecting control values based on model predictive control (MPC) and is possibly operated by an independent transmission system operator (TSO). Each MPC-based CA only knows a detailed local hybrid system model of its own area, employing reduced-order quasi steady-state (QSS) hybrid models of its neighboring areas and even simpler PV models for remote areas, to anticipate (and then optimize) the future behavior of its own area. Moreover, the neighboring CAs agree on communicating their planned future control input sequence in order to coordinate their own control actions. The feasibility of the proposed method for real-time applications is explained, and some practical implementation issues are also discussed. The performance of the method, using time-domain simulation of the Nordic32 test system, is compared with the uncoordinated decentralized MPC (no information exchange among CAs), demonstrating the improved behavior achieved by combining anticipation and coordination. The robustness of the control scheme against modeling uncertainties is also illustrated.
The Centre for Mathematics and Computer Science is a research institute of the Stichting Mathemat... more The Centre for Mathematics and Computer Science is a research institute of the Stichting Mathematisch Centrum; which was founded on February 11 , 1946, as a nonprofit institution aiming at the promotion of mathematics, computer science, and their applications. It is sponsored by the Dutch Government through the Netherlands Organization for the Advancement of Pure Research (Z.W.O.).
[1991] Proceedings of the 30th IEEE Conference on Decision and Control
... do not give information about about transient behaviour, in particular about transitions to l... more ... do not give information about about transient behaviour, in particular about transitions to locally stable equi-librilupoints corresponding to abad operating points ... though has a certain very small probability of of end-ing up in the domain of attraction of a bad operating point. ...
IFIP Advances in Information and Communication Technology, 2000
The goal of this paper is an algorithm to find the CLR and cell delay characteristics for realist... more The goal of this paper is an algorithm to find the CLR and cell delay characteristics for realistic ATM buffer systems with a large number N of reasonably complicated Markov modulated Bernoulli sources with M states per source. Matrix geometric methods have already reduced the complexity of finding these QoS measures by using rate matrices. However the dimensions of the rate matrices still grow exponentially with N. In ATM the number of sources at the input of these buffer systems is often so large that straightforward application of matrix geometric methods is impossible, since a set of (N-1)M 2 N nonlinear equations would have to be solved to obtain the rate matrices. This paper presents a technique, based on the spectral analysis of the rate matrix, which makes computing the CLR for large N feasible. Using the Kronecker product structure of the blocks of the transition matrix, the problem of finding the eigenvalues of the rate matrix can be reduced to solving a set of N + 1 non-linear scalar equations in the eigenvalue s of the rate matrix and in N dummy variables. Only 1 equation contains all variables; the other N equations contain 1 dummy variable and s. Most of the eigenvalues can be found by using repeated substitution in the set of equations, but for some unstable roots we need a combination of repeated substitution and Powell's Direction Set Method minimizing a squared error function. The eigenvectors of the rate matrix are obtained by solving as many sets of M linear scalar equations •The results presented in this paper have been
2010 The 2nd International Conference on Computer and Automation Engineering (ICCAE), 2010
We propose a measure for the validation of clusterings of gene expression data. This measure is a... more We propose a measure for the validation of clusterings of gene expression data. This measure is also useful to estimate missing gene expression levels, based on the similarity information contained in a given clustering. It is shown that this measure is an improvement over the figure of merit, an existing validation measure especially developed for clusterings of gene expression data.
Synthesis and Control of Discrete Event Systems, 2002
This paper discusses how the adaptive control paradigm can be used for reducing the computational... more This paper discusses how the adaptive control paradigm can be used for reducing the computational complexity of the synthesis of supervisory controllers for discrete event systems (timed or untimed) with partial observations. The adaptive control paradigm simplifies the design by assuming a priori that the control design is decomposed in two parts. The state space of the plant model can be partitioned in different “modes of operation”. The first component of the control loop is a “mode detector”, an observer that estimates the set of all “modes of operation” that are compatible with the past observations. The second component of the supervisory controller activates feedback controllers corresponding to each of these possible current “modes of operation”. This leads to a safe, but not maximally permissive control law, that is computationally much easier to design.
... 9 Page 10. 3] RK Boel and G. Stremersch. Forbidden state control synthesis for timed Petri ne... more ... 9 Page 10. 3] RK Boel and G. Stremersch. Forbidden state control synthesis for timed Petri net models. In M. Vidyasagar VD Blondel, ED Sontag and JC Willems, editors, Open Problems in Mathematical Systems and Control Theory, pages 61{66. Springer-Verlag London, 1998. ...
2015 54th IEEE Conference on Decision and Control (CDC), 2015
With which intensity to request high-quality components of the observed output of a Gaussian syst... more With which intensity to request high-quality components of the observed output of a Gaussian system driven by Brownian motions so as to minimize the trace of the error covariance when there is a cost for doing so? The optimal stochastic control problem is considered on an infinite horizon and with a discounted cost, and separately also for discounted impulse control. The optimal control law is for the scalar cases proven to be a threshold control law. The dynamic behavior of the closed-loop system is such that if the conditional variance is large then the sensor input for better quality observations is switched on while if the uncertainty is small then the input for better quality observations is switched off. The optimal control law for the drift input is identical to the classical LQG case.
This paper proposes a distributed coordination mechanism between local feedback controllers that ... more This paper proposes a distributed coordination mechanism between local feedback controllers that adapt the switching times of traffic lights at neighboring intersections. Some heavily loaded intersections are designated “leader intersections”. There, a local control agent sets switching times to minimize the expected queues, knowing vehicle passing times at local upstream sensors only, and sends its intended switching plan to neighboring “follower intersections”. Each follower agent uses this information to try to minimize the waste of green capacity at the neighboring leader intersection: in addition to minimizing its local queues, it also takes into account the expected queues that their switching decisions imply for their leader. We show, in realistic simulations, how the coordination introduced by this element allows to reduce queues not only at the leaders, but also at the follower nodes. The potential and key aspects of this scalable and simple coordinated control method for o...
This paper proposes a particle filter (PF) state estimator, using a platoon based model for urban... more This paper proposes a particle filter (PF) state estimator, using a platoon based model for urban traffic networks. The urban traffic network model consists of signalized intersections (representing queues of vehicles competing for service) connected to each other through links with predefined receiving capacities and stochastic delays. Sensors detect the passage of vehicles at the sensor locations. The algorithm is flexible and robust and can be used in real-time applications such as on-line control of switching times of traffic lights.
Urban traffic control poses a challenging problem in terms of coordinating the different traffic ... more Urban traffic control poses a challenging problem in terms of coordinating the different traffic lights that can be used in order to influence the traffic flow. Model based control requires hybrid systems models consisting of interacting fluid flow Petri net models for controlled and uncontrolled intersections, and cell transmission models for links connecting the intersections. This paper proposes a simulation based distributed model predictive control algorithm for solving this problem.
Proceedings of the 15th Wseas International Conference on Systems, Jul 14, 2011
This paper proposes a particle filter (PF) state estimator, using a platoon based model for urban... more This paper proposes a particle filter (PF) state estimator, using a platoon based model for urban traffic networks. The urban traffic network model consists of signalized intersections (representing queues of vehicles competing for service) connected to each other through links with predefined receiving capacities and stochastic delays. Sensors detect the passage of vehicles at the sensor locations. The algorithm is flexible and robust and can be used in real-time applications such as on-line control of switching times of traffic lights.
HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.
This book is the final report of the action COST TU0702 Real-time monitoring, surveillance and co... more This book is the final report of the action COST TU0702 Real-time monitoring, surveillance and control or road networks under adverse weather conditions. This Action was initiated with the main objectives of better understanding impacts of adverse weather on freeways, motorways, or urban traffic operations and developing, promoting and implementing strategies and tools to mitigate those impacts. This advanced interdisciplinary report is the second scientific report of TU0702 which covers all important topics related to adverse weather impact on transport networks, i.e. pavement surface conditions, traffic modeling for weather-dependent control applications, weather modeling and traffic management strategies during adverse weather conditions. It provides a comprehensive analysis on how adverse weather impacts transport infrastructure and users behaviors, and how to manage a safer and more productive road networks under these inclement weather conditions. It proceeds to the integration of weather into traffic modeling tools. It includes an extensive analysis on weather-sensitive traffic management tools, exemplified in terms of state of the art best practices. Finally, recommendations are provided on how road authorities can implement in an efficient manner weather sensitive-traffic management strategies for improved traffic safety. The TU0702 experts, through a consensus-building process, have identified major challenges and knowledge gaps that require major research efforts towards a more efficient weather-sensitive traffic management and sustainable network efficiency for enhanced safety and resilience.
This paper deals with the application of an anticipating and coordinating feedback control scheme... more This paper deals with the application of an anticipating and coordinating feedback control scheme in order to mitigate the long-term voltage instability of multi-area power systems. Each local area is uniquely controlled by a control agent (CA) selecting control values based on model predictive control (MPC) and is possibly operated by an independent transmission system operator (TSO). Each MPC-based CA only knows a detailed local hybrid system model of its own area, employing reduced-order quasi steady-state (QSS) hybrid models of its neighboring areas and even simpler PV models for remote areas, to anticipate (and then optimize) the future behavior of its own area. Moreover, the neighboring CAs agree on communicating their planned future control input sequence in order to coordinate their own control actions. The feasibility of the proposed method for real-time applications is explained, and some practical implementation issues are also discussed. The performance of the method, using time-domain simulation of the Nordic32 test system, is compared with the uncoordinated decentralized MPC (no information exchange among CAs), demonstrating the improved behavior achieved by combining anticipation and coordination. The robustness of the control scheme against modeling uncertainties is also illustrated.
The Centre for Mathematics and Computer Science is a research institute of the Stichting Mathemat... more The Centre for Mathematics and Computer Science is a research institute of the Stichting Mathematisch Centrum; which was founded on February 11 , 1946, as a nonprofit institution aiming at the promotion of mathematics, computer science, and their applications. It is sponsored by the Dutch Government through the Netherlands Organization for the Advancement of Pure Research (Z.W.O.).
[1991] Proceedings of the 30th IEEE Conference on Decision and Control
... do not give information about about transient behaviour, in particular about transitions to l... more ... do not give information about about transient behaviour, in particular about transitions to locally stable equi-librilupoints corresponding to abad operating points ... though has a certain very small probability of of end-ing up in the domain of attraction of a bad operating point. ...
IFIP Advances in Information and Communication Technology, 2000
The goal of this paper is an algorithm to find the CLR and cell delay characteristics for realist... more The goal of this paper is an algorithm to find the CLR and cell delay characteristics for realistic ATM buffer systems with a large number N of reasonably complicated Markov modulated Bernoulli sources with M states per source. Matrix geometric methods have already reduced the complexity of finding these QoS measures by using rate matrices. However the dimensions of the rate matrices still grow exponentially with N. In ATM the number of sources at the input of these buffer systems is often so large that straightforward application of matrix geometric methods is impossible, since a set of (N-1)M 2 N nonlinear equations would have to be solved to obtain the rate matrices. This paper presents a technique, based on the spectral analysis of the rate matrix, which makes computing the CLR for large N feasible. Using the Kronecker product structure of the blocks of the transition matrix, the problem of finding the eigenvalues of the rate matrix can be reduced to solving a set of N + 1 non-linear scalar equations in the eigenvalue s of the rate matrix and in N dummy variables. Only 1 equation contains all variables; the other N equations contain 1 dummy variable and s. Most of the eigenvalues can be found by using repeated substitution in the set of equations, but for some unstable roots we need a combination of repeated substitution and Powell's Direction Set Method minimizing a squared error function. The eigenvectors of the rate matrix are obtained by solving as many sets of M linear scalar equations •The results presented in this paper have been
2010 The 2nd International Conference on Computer and Automation Engineering (ICCAE), 2010
We propose a measure for the validation of clusterings of gene expression data. This measure is a... more We propose a measure for the validation of clusterings of gene expression data. This measure is also useful to estimate missing gene expression levels, based on the similarity information contained in a given clustering. It is shown that this measure is an improvement over the figure of merit, an existing validation measure especially developed for clusterings of gene expression data.
Synthesis and Control of Discrete Event Systems, 2002
This paper discusses how the adaptive control paradigm can be used for reducing the computational... more This paper discusses how the adaptive control paradigm can be used for reducing the computational complexity of the synthesis of supervisory controllers for discrete event systems (timed or untimed) with partial observations. The adaptive control paradigm simplifies the design by assuming a priori that the control design is decomposed in two parts. The state space of the plant model can be partitioned in different “modes of operation”. The first component of the control loop is a “mode detector”, an observer that estimates the set of all “modes of operation” that are compatible with the past observations. The second component of the supervisory controller activates feedback controllers corresponding to each of these possible current “modes of operation”. This leads to a safe, but not maximally permissive control law, that is computationally much easier to design.
... 9 Page 10. 3] RK Boel and G. Stremersch. Forbidden state control synthesis for timed Petri ne... more ... 9 Page 10. 3] RK Boel and G. Stremersch. Forbidden state control synthesis for timed Petri net models. In M. Vidyasagar VD Blondel, ED Sontag and JC Willems, editors, Open Problems in Mathematical Systems and Control Theory, pages 61{66. Springer-Verlag London, 1998. ...
2015 54th IEEE Conference on Decision and Control (CDC), 2015
With which intensity to request high-quality components of the observed output of a Gaussian syst... more With which intensity to request high-quality components of the observed output of a Gaussian system driven by Brownian motions so as to minimize the trace of the error covariance when there is a cost for doing so? The optimal stochastic control problem is considered on an infinite horizon and with a discounted cost, and separately also for discounted impulse control. The optimal control law is for the scalar cases proven to be a threshold control law. The dynamic behavior of the closed-loop system is such that if the conditional variance is large then the sensor input for better quality observations is switched on while if the uncertainty is small then the input for better quality observations is switched off. The optimal control law for the drift input is identical to the classical LQG case.
This paper proposes a distributed coordination mechanism between local feedback controllers that ... more This paper proposes a distributed coordination mechanism between local feedback controllers that adapt the switching times of traffic lights at neighboring intersections. Some heavily loaded intersections are designated “leader intersections”. There, a local control agent sets switching times to minimize the expected queues, knowing vehicle passing times at local upstream sensors only, and sends its intended switching plan to neighboring “follower intersections”. Each follower agent uses this information to try to minimize the waste of green capacity at the neighboring leader intersection: in addition to minimizing its local queues, it also takes into account the expected queues that their switching decisions imply for their leader. We show, in realistic simulations, how the coordination introduced by this element allows to reduce queues not only at the leaders, but also at the follower nodes. The potential and key aspects of this scalable and simple coordinated control method for o...
This paper proposes a particle filter (PF) state estimator, using a platoon based model for urban... more This paper proposes a particle filter (PF) state estimator, using a platoon based model for urban traffic networks. The urban traffic network model consists of signalized intersections (representing queues of vehicles competing for service) connected to each other through links with predefined receiving capacities and stochastic delays. Sensors detect the passage of vehicles at the sensor locations. The algorithm is flexible and robust and can be used in real-time applications such as on-line control of switching times of traffic lights.
Urban traffic control poses a challenging problem in terms of coordinating the different traffic ... more Urban traffic control poses a challenging problem in terms of coordinating the different traffic lights that can be used in order to influence the traffic flow. Model based control requires hybrid systems models consisting of interacting fluid flow Petri net models for controlled and uncontrolled intersections, and cell transmission models for links connecting the intersections. This paper proposes a simulation based distributed model predictive control algorithm for solving this problem.
Proceedings of the 15th Wseas International Conference on Systems, Jul 14, 2011
This paper proposes a particle filter (PF) state estimator, using a platoon based model for urban... more This paper proposes a particle filter (PF) state estimator, using a platoon based model for urban traffic networks. The urban traffic network model consists of signalized intersections (representing queues of vehicles competing for service) connected to each other through links with predefined receiving capacities and stochastic delays. Sensors detect the passage of vehicles at the sensor locations. The algorithm is flexible and robust and can be used in real-time applications such as on-line control of switching times of traffic lights.
HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.
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