Characterising Angular Accelerometer Calibration Setup Disturbance Using Box–Jenkins Method

Abstract

Angular acceleration feedback is a powerful concept when designing a model-free, state-of-the-art Fault-Tolerant Flight Control (FTFC) system. Such feedback is currently being obtained by differentiating the rate gyro signals [1], which amplifies the noise component and introduces delay [2]. Considering feedback is a valuable tool to adjust the performance and to ultimately meet the desired result, the feedback signal accuracy will determine the system’s successful control actions. To incorporate the angular acceleration feedback in the FTFC system design, analysis and simulation, a proper angular accelerometer model is of substantial concern. Creating a controller based on an incorrect angular accelerometer, for example, could result in the control not meeting the desired control variables. Therefore, establishing a proper angular accelerometer system identification method is crucial to achieving the correct model. The frequency response data generates the current angular accelerometer model in a transfer function form [3]. Frequency domain data provides the required accuracy to calculate the Frequency Response Function (FRF) in this approach. Specifying the sensor bandwidth as well as recognising the system’s phase are the additional advantages of this method. The Auto-Regressive with exogenous terms (ARX) model is employed as the first stage estimation due to its efficiency in estimating the polynomial because it is the result of solving linear regression equations in analytic form. Moreover, the result is distinctive; it always fulfils the global minimum of the loss function. The ARX model, therefore, is favoured, especially when the model order is high.