| 1. |
- Aminifar, Amir
(författare)
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Self-Triggered Controllers, Resource Sharing, and Hard Guarantees
- 2016
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Ingår i: 2016 2ND INTERNATIONAL CONFERENCE ON EVENT-BASED CONTROL, COMMUNICATION, AND SIGNAL PROCESSING (EBCCSP). - : IEEE. - 9781509041961
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Konferensbidrag (refereegranskat)abstract
- Today, many control applications in embedded and cyber-physical systems are implemented on shared platforms, alongside other hard real-time or safety-critical applications. Having the resource shared among several applications, to provide hard guarantees, it is required to identify the amount of resource needed for each application. This is rather straightforward when the platform is shared among periodic control and periodic real-time applications. In the case of event-triggered and self-triggered controllers, however, the execution patterns and, in turn, the resource usage are not clear. Therefore, a major implementation challenge, when the platform is shared with self-triggered controllers, is to provide hard and efficient stability and schedulability guarantees for other applications. In this paper, we identify certain execution patterns for self-triggered controllers, using which we are able to provide hard and efficient stability guarantees for periodic control applications.
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| 2. |
- Cervin, Anton
(författare)
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LQG-optimal PI and PID control as benchmarks for event-based control
- 2016
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Ingår i: 2016 2nd International Conference on Event-Based Control, Communication, and Signal Processing, EBCCSP 2016 - Proceedings. - 9781509041961
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Konferensbidrag (refereegranskat)abstract
- We formulate two simple benchmark problems for event-based control, where the optimal solutions in the continuous-time setting turn out to be ordinary PI and PID controllers. The benchmarks can be used to compare the performance of continuous-time, discrete-time, and various event-based controllers with regard to for instance disturbance attenuation, control effort, and average sampling or actuation rates. They can also be used to evaluate heuristic event-based PI(D) controllers and see how their performance compare to each other and to regular sampled-data control. We give two benchmark examples, where we study the trade-off between event frequency and regulator performance for a number of previously proposed approaches to event-based control.
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| 3. |
- Podgorski, Krzysztof, et al.
(författare)
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Distributions at random events
- 2016
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Ingår i: 2016 2ND INTERNATIONAL CONFERENCE ON EVENT-BASED CONTROL, COMMUNICATION, AND SIGNAL PROCESSING (EBCCSP). - 9781509041961 ; , s. 1-8
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Konferensbidrag (refereegranskat)abstract
- We discuss the generalized Rice formula approach to deriving long-run distributions of characteristics defined at random events of a stochastic process or field. The approach stems from the same principle originally introduced by Rice for the level crossing intensity in a random signal and we review its extensions to more general contexts.Events are defined on random surfaces through crossing levels of (multivariate) stochastic fields.We also account for the dynamics of spatial-temporal fields using observed velocities. Extensions beyond the Gaussian model are shown and models for sampling from the level crossing distributions are presented.The importance of these generalizations for applications is illustrated through examples.
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| 4. |
- Podgorski, Krzysztof, et al.
(författare)
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Distributions of spatial wave size for random fields
- 2016
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Ingår i: 2nd International Conference on Event-Based Control, Communication, and Signal Processing (EBCCSP), Krakow, POLAND, JUN 13-15, 2016. - 9781509041961
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Konferensbidrag (refereegranskat)abstract
- A method of measuring three-dimensional spatial wave size is proposed and statistical distributions of the size characteristics are derived in explicit integral forms for Gaussian sea surfaces. New definitions of wave characteristics such as the crest-height, the length, the size and the wave front location are provided in fully dimensional context. The joint statistical distributions of these wave characteristics are derived using the Rices formulas for expected numbers of local maximum and distance from a local maximum to a level crossing countour. %The methodology will be also illustrated by some examples from other type of engineering applications. Review of the Rice's method to study crossing distributions is given.
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| 5. |
- Thelander Andrén, Marcus, et al.
(författare)
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Event-Based State Estimation Using an Improved Stochastic Send-on-Delta Sampling Scheme
- 2016
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Ingår i: 2016 Second International Conference on Event-based Control, Communication, and Signal Processing (EBCCSP). - 9781509041961
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Konferensbidrag (refereegranskat)abstract
- Event-based sensing and communication holds the promise of lower resource utilization and/or better performance for remote state estimation applications found in e.g. networked control systems. Recently, stochastic event-triggering rules have been proposed as a means to avoid the complexity of the problem that normally arises in event-based estimator design. By using a scaled Gaussian function in the stochastic triggering scheme, the optimal remote state estimator becomes a linear Kalman filter with a case dependent measurement update. In this paper we propose a modified version of the stochastic send-on-delta triggering rule. The idea is to use a very simple predictor in the sensor, which allows the communication rate to be reduced while preserving estimation performance compared to regular stochastic send-on-delta sampling. We derive the optimal mean-square error estimator for the new scheme and present upper and lower bounds on the error covariance. The proposed scheme is evaluated in numerical examples, where it compares favorably to previous stochastic sampling approaches, and is shown to preserve estimation performance well even at large reductions in communication rate.
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