METHOD OF DISCRETE MODELING AND ITS APPLICATION TO ESTIMATION OF TF30 ENGINE VARIABLES

摘要

A method of discrete modeling is presented that effectively isolates steady-state model accuracy from dynamic model accuracy. The steady-state model may be generated from the engine de¬sign equations with any desired degree of accuracy. The dynamic model is generated by apply-ing a step disturbance of a manipulated variable to an open-loop engine simulation. The sam¬pled response of the variable is combined with the steady-state model's response to form a set of weighting factors. These weighting factors are then used to weight past values of the manip¬ulated variable, thus forming the dynamic model. The method is used to estimate various TF30-P-3 engine variables. A dynamic trim function is developed to compensate for the dy¬namic nonlinearities of the variables as well as for inaccuracies in dynamic definition. The trim function is shown to be related to the square root of the sum of the squares of the weighting factors obtained at various engine operating conditions. Finally, the estimation of variables with¬out dynamic modeling is discussed.