Using Uppaal for the secure and optimal control of AGV fleets

The design and realization of an on line control system for automated guided vehicles (AGV) is addressed. A synthesis method is proposed based on the use of the model checking tool for timed automata Uppaal. This system has to route the vehicles while ensuring the system safeness, a good coordination between vehicles and the optimization of performance criteria.This problem is like synthesizing a Ramadge and Wonham supervisor combined with routing and optimizing functions, that is an ongoing problem within the supervisory control theory. The proposed concepts are validated through a software tool suite based on Uppaal in order to generate optimal traces and interact with an AGV system emulated with Arena

Modelling, Optimization And Control Of Subway Systems.

A methodology that improves the operational use of reference schedules for the North-South line of the Metro Company of Sao Paulo is presented. Improvements with respect to the reference schedules are obtained by exploring the fact that the model used to generate reference schedules does not differentiate trains being dispatched from the Jabaquara yard. The strategy takes into account the maximum delay time possible with respect to the arrival time of each train in Jabaquara such that no train exceeds its capacity, and there is no violation of physical constraints imposed by the system or by maintenance requirements. Based on the limits determined above, the reference schedule is modified to adjust the arrival times at Jabaquara in order to redispatch trains. This methodology has been implemented and computer simulations have shown that it can improve further the operational utilization of trains.616516

Robust Controller Synthesis for Hybrid Systems Using Modal Logic

. In this paper, we formulate and robustly solve a quite general class of hybrid controller synthesis problems. The type of controller we investigate is the switching control mechanism of a hybrid automaton (via guard and mode invariant sets), and the robustness result is with respect to variations in the right hand sides of the dierential equations that depend continuously on a parameter. We present a novel methodology for controller design and synthesis which uses modal logic as a formalism for reasoning about sets of plant states, and various operators on sets arising from the dierential equations and from metric tolerance relations on the state space. 1 Introduction In general terms, a hybrid system H can be said to satisfy a performance speci cation robustly if every system H 0 in some nominated variation class around H also satis es that speci cation. Likewise, a synthesis procedure for a class of control problems can be called robust if the nominal closed-loop hyb..

Model checking LTL over controllable linear systems is decidable

The use of algorithmic verification and synthesis tools for hybrid systems is currently limited to systems exhibiting simple continuous dynamics such as timed automata or rectangular hybrid systems. In this paper we further enlarge the class of systems amenable to algorithmic analysis and synthesis by showing decidability of model checking Linear Temporal Logic (LTL) formulas over discrete time, controllable, linear systems. This result follows from the construction of a language equivalent, finite abstraction of a control system based on a set of finite observations (the atomic propositions appearing in a given LTL formula). Furthermore, the size of this abstraction is shown to be polynomial in the dimension of the control system and the number of observations. These results open the doors for verification and synthesis of continuous and hybrid control systems from LTL specifications.