Search results for " manufacturing systems"

showing 3 items of 3 documents

ROBUST CONTROL STRATEGIES FOR MULTI—INVENTORY SYSTEMS WITH AVERAGE FLOW CONSTRAINTS

2006

Abstract In this paper we consider multi—inventory systems in presence of uncertain demand. We assume that i) demand is unknown but bounded in an assigned compact set and ii) the control inputs (controlled flows) are subject to assigned constraints. Given a long—term average demand, we select a nominal flow that feeds such a demand. In this context, we are interested in a control strategy that meets at each time all possible current demands and achieves the nominal flow in the average. We provide necessary and sufficient conditions for such a strategy to exist and we characterize the set of achievable flows. Such conditions are based on linear programming and thus they are constructive. In …

Inventory controlMathematical optimizationManufacturing systemLinear programmingBounded disturbancesBounded disturbanceBounded disturbances; Inventory control; Linear programming; Manufacturing systems; Robust controlRobust controlContext (language use)General MedicineDynamic problemFlow (mathematics)Inventory control Robust control Bounded disturbances Manufacturing systems Linear programming.Control and Systems EngineeringControl theoryBounded functionLinear programmingSettore MAT/09 - Ricerca OperativaManufacturing systemsElectrical and Electronic EngineeringSpecial caseRobust controlMathematicsInventory control
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A hierarchic approach to production planning and scheduling of a flexible manufacturing system

1999

Abstract The paper deals with the problem of improving the machine utilization of a flexible manufacturing cell. Limited tool magazine space of the machines turns out to be a relevant bottleneck. A hierarchic approach for this problem is proposed. At the upper level, sets of parts that can be concurrently processed (batches) are determined. At the lower levels, batches are sequenced, linked, and scheduled. Methods taken from the literature are used for the solution of the latter subproblems, and an original mixed integer programming model is formulated to determine batches. The proposed methods are discussed on the basis of computational experience carried out on real instances.

Mathematical optimizationEngineeringbusiness.industryFlexible manufacturing systemsGeneral MathematicsFlexible manufacturing systemScheduling (production processes)Production planningFlexible manufacturing systemIndustrial and Manufacturing EngineeringBottleneckManufacturing engineeringComputer Science ApplicationsProduction planningMachine utilizationComputer-integrated manufacturingControl and Systems EngineeringToolingManufacturing cellbusinessInteger programmingProduction planning; Flexible manufacturing systems; Tooling; Mathematic; SimulationSoftwareMathematicSimulation
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Robust control of uncertain multi-inventory systems via linear matrix inequality

2008

We consider a continuous time linear multi inventory system with unknown demands bounded within ellipsoids and controls bounded within ellipsoids or polytopes. We address the problem of "-stabilizing the inventory since this implies some reduction of the inventory costs. The main results are certain conditions under which "-stabilizability is possible through a saturated linear state feedback control. All the results are based on a Linear Matrix Inequalities (LMIs) approach and on some recent techniques for the modeling and analysis of polytopic systems with saturations.

Mathematical optimizationLinear Matrix InequalitiesPolytopeDynamical Systems (math.DS)stock control93xxcontinuous systems linear matrix inequalities linear systems manufacturing systems robust control state feedback stock control uncertain systemsimpulse control inventory control hybrid systemsSettore ING-INF/04 - AutomaticaControl theoryFOS: Mathematicsmanufacturing systemsMathematics - Dynamical Systemslinear matrix inequalitiesstate feedbackTime complexityMathematics - Optimization and ControlInventory systemsMathematicsInventory controlLinear Matrix Inequalities; Inventory systemsLinear systemlinear systemsLinear matrix inequality93Cxx;93xxLinearity93Cxxhybrid systemsEllipsoidComputer Science Applicationsimpulse control; inventory control; hybrid systemsuncertain systemsControl and Systems EngineeringOptimization and Control (math.OC)Control systemBounded functioncontinuous systemsPerpetual inventorycontinuous systems; linear matrix inequalities; linear systems; manufacturing systems; robust control; state feedback; stock control; uncertain systemsinventory controlRobust controlSettore MAT/09 - Ricerca Operativarobust controlimpulse control
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