| 1. |
- Luspay, T., et al.
(författare)
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Ramp metering for flow maximisation and emission reduction – a set-based multi-objective design approach
- 2017
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Ingår i: Transportation Research Procedia. - : Elsevier BV. - 2352-1465 .- 2352-1457. ; 27, s. 937-944
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Konferensbidrag (refereegranskat)abstract
- A set-theoretical approach is presented for a multi-objective control design of the local ramp metering problem. Two control objectives are specified: first, the optimization of traffic performance, by the minimization of total time spent.Second, the emission factor of CO2 is minimized. The optimal state for traffic emission however lies in the unstable domain of the system. To resolve this inconsistency, the control problem is formalized in a set-theoretical context. For this purpose, the nonlinear METANET model is rewritten in a shifted coordinate frame in a parameter-varying, polytopic representation. Bounds on state-, input- and disturbance variables are expressed by convex polytopes. These sets are then used for the design of an interpolated H∞ controller that is capable of improving traffic conditions according to the prescribed multi-objective criteria.
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| 2. |
- Luspay, T., et al.
(författare)
-
Set-theoretic analysis of the isolated ramp metering problem
- 2016
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Ingår i: International Journal of Robust and Nonlinear Control. - : Wiley. - 1099-1239 .- 1049-8923. ; 26:6, s. 1246-1266
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Tidskriftsartikel (refereegranskat)abstract
- Analysis of ramp metering, as an effective freeway traffic control solution, is focused in the paper. Thestudied traffic control problem is discussed in a set-theoretic context in order to quantitatively characterize its effectiveness. The notions of maximal robust controlled invariant set, as well as t-step robust controllable set are defined and used for analyzing the ramp metering problem independently of the control policy applied. Algorithms are developed to compute these sets, with special attention to their practical interpretations.Numerical examples with graphical representation of the proposed methodology are given to examine localramp metering and conclude implications to control strategies.
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