Linear programming design of multivariable feedback controllers for the NERVA nuclear engine

The application of Linear Programming (LP) to the design of state variable feedback controllers for multivariable plants with known deterministic inputs is described. The design problem is solved in two steps. The first step consists of an open-loop optimization in which LP is used to determine the plant input vector profile which optimizes the plant response to a specified demand. The second step, also implemented by LP, produces the controller parameters (a matrix of constant gains) and consists of an optimum fitting, through the feedback controller, of the input and feedback error vector profiles determined in the first step. The performance criterion used is the minimum Integral Weighted Absolute Value (IWAV). The technique is illustrated with an application to the NERVA nuclear rocket engine controller design.