Patent ID: 7433742
Filing Date: 2008-10-07
Classification: G06Q

Abstract:
1. An apparatus for optimizing the performance of a controlled system over a plurality of times, said apparatus comprising: a plurality of process control devices for controlling said controlled system in response to control signals from the apparatus, a plurality of sensors for sensing variable conditions of the controlled system by the apparatus, a means for modeling said controlled system by a conceptual fluid-model, a means for calculating optimal control signals for the control of said controlled system, wherein said controlled system comprises a plurality of discrete items, a plurality of actions, and a plurality of resources, where at each of said times each of said items is in one of a plurality of classes, and where application of one of said actions to one of said items in one of said classes at one of said times will change the class of the item, and where said application of one of said actions to one of said items at one of said times will consume some of said resources, and wherein the control of the said controlled system comprises the timing of said actions and the allocation of said resources to said actions, and wherein said means of the apparatus for modeling said controlled system by a conceptual fluid-model comprise: a plurality of state functions that denote levels of fluids in buffers as a function of time, where the fluid in a buffer at time t approximates the number of items in a corresponding class in the controlled system around the time t, and a plurality of control functions that denote flow rates as a function of time, where a flow rate at time t represents the number of applications of a corresponding action in the controlled system system around the time t, and a linear relationship between the flow rates and the rates of change of the state of the fluid-model system at time t, and a linear relationship between the flow rates of the fluid-model system at time t and the rate of consumption of resources, and wherein said means of the apparatus for calculating optimal control signals comprise an algorithm for a solution of separated continuous linear programming problems, and wherein the operation of the apparatus comprises the repeated applications of the steps: (a) setting current-time to 0, and setting time-horizon to a predetermined value T, and using the apparatus sensing devices to (b) solving said separated continuous linear programming optimization problem, by an algorithm comprising a sequence of iterations, each of said iterations comprising (d) producing control signals for controlling the real system in accordance with the optimal solution of the fluid-model system, where the repeated application of the steps (a), (b), and (c) is performed at a plurality of predetermined decision times.