| 1. |
- Adaldo, Antonio, 1989-, et al.
(författare)
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Control of Multi-Agent Systems with Event-Triggered Cloud Access
- 2015
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Ingår i: Proceedings of the 14th annual European Control Conference. - : IEEE. - 9783952426937 ; , s. 954-961
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Konferensbidrag (refereegranskat)abstract
- This paper investigates a multi-agent formation control problem with event-triggered control updates and additive disturbances. The agents communicate only by exchanging information in a cloud repository. The communication with the cloud is considered a shared and limited resource, and therefore it is used intermittently and asynchronously by the agents. The proposed approach takes advantage of having a shared asynchronous cloud support while guaranteeing a reduced number of communication. More in detail, each agent schedules its own sequence of cloud accesses in order to achieve a coordinated network goal. A control law is given with a criterion for scheduling the control updates recursively. The closed loop scheme is proven to be effective in achieving the control objective and a numerical simulation corroborates the theoretical results.
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| 2. |
- Adaldo, Antonio, et al.
(författare)
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Coordination of multi-agent systems with intermittent access to a cloud repository
- 2017
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Ingår i: Workshop on Sensing and Control for Autonomous Vehicles. - Cham : Springer. - 9783319553719 ; , s. 453-471
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Konferensbidrag (refereegranskat)abstract
- A cloud-supported multi-agent system is composed of autonomous agents required to achieve a common coordination objective by exchanging data over a shared cloud repository. The repository is accessed asychronously by different agents, and direct inter-agent commuication is not possible. This model is motivated by the problem of coordinating a fleet of autonomous underwater vehicles, with the aim to avoid the use of expensive and power-hungry modems for underwater communication. For the case of agents with integrator dynamics, a control law and a rule for scheduling the cloud access are formally defined and proven to achieve the desired coordination. A numerical simulation corroborate the theoretical results.
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| 3. |
- Adaldo, Antonio, 1989-, et al.
(författare)
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Event-triggered pinning control of complex networks with switching topologies
- 2014
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Ingår i: Proceedings of the 53rd annual IEEE Conference on Decision and Control. - 9781479977468 ; , s. 2783-2788
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Konferensbidrag (refereegranskat)abstract
- This paper investigates the problem of eventtriggered pinning control for the synchronization of networks of nonlinear dynamical agents onto a desired reference trajectory. The pinned agents are those that have access to the reference trajectory. We consider both static and switching topologies. We prove that the system is well posed and identify conditions under which the network achieves exponential convergence. A lower bound for the rate of convergence is also derived. Numerical examples demonstrating the effectiveness of the results are provided.
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| 4. |
- Ahmadi, Seyed Alireza, et al.
(författare)
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Towards more efficient building energy management systems
- 2012
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Ingår i: Proceedings - 2012 7th International Conference on Knowledge, Information and Creativity Support Systems, KICSS 2012. - : IEEE. - 9780769548616 ; , s. 118-125
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Konferensbidrag (refereegranskat)abstract
- As a first step towards developing efficient building energy management techniques, in this paper, we first study the energy consumption patterns of heating, ventilation and cooling (HVAC) systems across the KTH Royal Institute of Technology campus and we identify some possible areas where energy consumption can be made less wasteful. Later, we describe a test-bed where wireless sensor networks are used to collect data and eventually control the HVAC system in a distributed way. We present some of the data, temperature, humidity, and CO2 measurements, that are collected by the aforementioned network and compare them with the measurements collected by the legacy sensors already in place. In the end we present a preliminary result on modelling the dynamics of the temperature, humidity, and CO2 using the data gather by the sensor network. We check the validity of the model via comparing the out put of the system with measured data. As a future work we identify the possibility of using the models obtained here for model based control, and fault detection and isolation techniques.
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| 5. |
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| 6. |
- Al Alam, Assad, et al.
(författare)
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An experimental study on the fuel reduction potential of heavy duty vehicle platooning
- 2010
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Ingår i: 13th International IEEE Conference on Intelligent Transportation Systems (ITSC), 2010. - : IEEE. ; , s. 306-311
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Konferensbidrag (refereegranskat)abstract
- Vehicle platooning has become important for the vehicle industry. Yet conclusive results with respect to the fuel reduction possibilities of platooning remain unclear. The focus in this study is the fuel reduction that heavy duty vehicle platooning enables and the analysis with respect to the influence of a commercial adaptive cruise control on the fuel consumption. Experimental results show that by using preview information of the road ahead from the lead vehicle, the adaptive cruise controller can reduce the fuel consumption. A study is undertaken for various masses of the lead vehicle. The results show that the best choice with respect to a heavier or lighter lead vehicle depends on the desired time gap. A maximum fuel reduction of 4.7-7.7% depending on the time gap, at a set speed of 70 km/h, can be obtained with two identical trucks. If the lead vehicle is 10 t lighter a corresponding 3.8-7.4% fuel reduction can be obtained depending on the time gap. Similarly if the lead vehicle is 10 t heavier a 4.3-6.9% fuel reduction can be obtained. All results indicate that a maximum fuel reduction can be achieved at a short relative distance, due to both air drag reduction and suitable control.
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| 7. |
- Al Alam, Assad, et al.
(författare)
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Establishing safety for heavy duty vehicle platooning : a game theoretical approach
- 2011
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Ingår i: IFAC Proceedings Volumes (IFAC-PapersOnline). ; , s. 3818-3823
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Konferensbidrag (refereegranskat)abstract
- It is fuel efficient to minimize the relative distance between vehicles to achievea maximum reduction in air drag. However, the relative distance can only be reduced to acertain extent without endangering a collision. Factors such as the vehicle velocity, the relativevelocity, and the characteristics of the vehicle ahead has a strong impact on what minimumrelative distance can be obtained. In this paper, we utilize optimal control and game theory toestablish safety criteria for heavy duty vehicle platooning applications. The derived results showthat a minimum relative distance of 1.2m can be obtained for two identical vehicles withoutendangering a collision, assuming that there is no delay present in the feedback system. If aworst case delay is present in the system, a minimum relative distance is deduced based uponthe vehicle’s maximum deceleration ability. The relative distance can be reduced if the followervehicle has a greater overall braking capability, which suggests that vehicle heterogeneity andorder has substantial impact. The findings are verified by simulations and the main conclusion isthat the relative distance utilized in commercial applications today can be reduced significantlywith a suitable advanced cruise control system.
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| 8. |
- Alam, Assad, 1982-, et al.
(författare)
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Suboptimal Decentralized Controller Design for Chain Structures : Applications to Vehicle Formations
- 2011
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Ingår i: IEEE 50th Annual Conference on Decision and Control and European Control Conference, Orlando, December, 2011. - : IEEE. ; , s. 6894-6900
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Konferensbidrag (refereegranskat)abstract
- We consider suboptimal decentralized controllerdesign for subsystems with interconnected dynamics and costfunctions. A systematic design methodology is presented overthe class of linear quadratic regulators (LQR) for chain graphs.The methodology is evaluated on heavy duty vehicle platooningwith physical constraints. A simulation and frequency analysisis performed. The results show that the decentralized controllergives good tracking performance and a robust system. We alsoshow that the design methodology produces a string stablesystem for an arbitrary number of vehicles in the platoon, ifthe vehicle configurations and the LQR weighting parametersare identical for the considered subsystems.
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| 9. |
- Alexandre, Seuret, et al.
(författare)
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Consensus of Double Integrator Multi-agents under Communication Delay
- 2009
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Ingår i: IFAC Proceedings Volumes (IFAC-PapersOnline). - : Elsevier BV. - 1474-6670. ; , s. 376-381
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Konferensbidrag (refereegranskat)abstract
- This paper deals with the consensus problem under network induced communication delays. It is well-known that introducing a delay generally leads to a reduce of the performance or to instability. Thus, investigating the impact of time-delays in the consensus problem is an important issue. Another important issue is to obtain an estimate of the convergence rate, which is not straightforward when delays appear in the network. In this paper, the agents are modelled as double integrator systems. It is assumed that each agent receives instantaneously its own output information but receives the information from its neighbors after a constant delay. A stability criterion is provided based on Lyapunov-Krasovskii techniques and is expressed in terms of LMI. An expression of the consensus equilibrium which depends on the delay and on the initial conditions taken in an interval is derived. The results are supported through several simulations for different network symmetric communication schemes.
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| 10. |
- Altaf, Faisal, et al.
(författare)
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Wireless event-triggered controller for a 3D tower crane lab process
- 2011
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Ingår i: 2011 19th Mediterranean Conference on Control and Automation, MED 2011. - 9781457701252 - 9781457701245 ; , s. 994-1001
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Konferensbidrag (refereegranskat)abstract
- This paper studies the design and real-time implementation of an event-triggered controller for a nonlinear 3D tower crane where the communication between the controller and the actuators is performed over a low-power wireless network. A flexible Event-Generation Circuit (EGC) is proposed in order to implement event-driven controllers for Networked Control Systems. Furthermore, a detailed experimental analysis on the performance of the event-triggered controller and the influence of packet losses on the transmitted actuation messages are presented. The results show that the event-triggered controllers in networked control systems are able to maintain the same level of performance as compared to periodic controllers, while increasing the sensors/actuators lifetime by reducing network bandwidth utilization.
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