Frequency Response Estimation for Multiple Aircraft Control Loops Using Orthogonal Phase-Optimized Multisine Inputs

Abstract

The latest advances made at NASA for simultaneous excitation in multiple axes and the identification of frequency responses for aircraft flight systems are discussed in this paper. These techniques are extended in the prospect of identifying multiple dynamics and control loops for multiple axes. Recent applications with flight test data and simulation data are also presented, along with a discussion of the practical aspects of the approach. A demonstration is also provided, using a simulation model for the X-59 airplane in which frequency responses for the bare-airframe, closed-loop, and broken-loop (both for the actuator and the sensor) dynamics were identified from a single 60 s maneuver. The results indicate that this approach can significantly shorten the duration of flight tests and Monte Carlo simulations to save time and costs, and can produce results in real time.