Application of the Least Squares Method to Estimate the Gain of the Mathematical Model of the Aircraft Structure Strength Test Bench

The problrm of the improving accuracy of carrying out resource and static strength tests of elements of structures of aviation and space technology is considered. Increased accuracy of power loading of structures is achieved by evaluation of gain of control channel of electrohydraulic test bench during fatigue testing, where the gain can vary within wide limits depending on properties of test object and characteristics of electrohydraulic drive. The least squares method with a sliding window is used as the method for identifying this coefficient. Then the obtained gain estimate is applied to adapt the parameters of the electrical drive controller of the bench. Proposed approach makes it possible to increase accuracy of implementation of the desired profile of power loading of structures, as well as to eliminate possibility of occurrence of high-frequency oscillations in control loop. The results of the experimental test of the proposed approach on a single-channel test bench are given too.