Resource-Optimal Scheduling Using Priced Timed Automata

Abstract

In this paper, we show how the simple structure of the linear programs encountered during symbolic minimum-cost reachability analysis of priced timed automata can be exploited in order to substantially improve the performance of the current algorithm. The idea is rooted in duality of linear programs and we show that each encountered linear program can be reduced to the dual problem of an instance of the min-cost flow problem. Thus, we only need to solve instances of the much simpler min-cost flow problem during minimum-cost reachability analysis. Experimental results using Uppaal show a 70-80 percent performance gain. As a main application area, we show how to solve energy-optimal task graph scheduling problems using the framework of priced timed automata.

Optimal Strategies in Priced Timed Game Automata

“…Efficient incorporation in Uppaal is provided by use of so-called priced zones as a main data structure [LBB + 01]. In [RLS04] the implementation of cost-optimal reachability is improved considerably by exploiting duality between linear programming problems over zones with min-cost flow problems. More recently [BBL04], the problem of computing optimal infinite schedules (in terms of minimal limit-ratios) is solved for the model of priced timed automata.…”

Almost Optimal Strategies in One Clock Priced Timed Games

“…An interesting direction of real-time model checking that has recently received substantial attention is to extend and re-target timed automata technology towards optimal scheduling and planning [1,15,9]. In particular, as part of this effort, the notion of priced timed automata [6,5] has been promoted as a useful extension of the classical model of timed automata [4].…”

“…[6] and [5] independently show computability of the cost-optimal reachability for priced (or weighted) timed automata using different adaptations of the so-called region technique. In [13,15] the notion of priced zone is developed allowing efficient implementation of cost-optimal reachability as witnessed by the competitive tool UPPAAL Cora [16]. Also the problem of computing optimal infinite schedules (in terms of minimal limit-ratios) has been shown computable [8].…”

Real-Time Model Checking on Secondary Storage

“…UPPAAL CORA [20] is the extension of UPPAAL designed for efficient cost-optimal reachability analysis in priced timed automata. UP-PAAL CORA is also competitive in resource-optimal scheduling [23].…”