Title: System identification of the quadrotor with inner loop stabilisation system

Authors: Minhuan Guo; Yan Su; Dongbing Gu

Addresses: School of Mechanical Engineering, Nanjing University of Science and Technology, No. 200 Xiaolingwei Street, China ' School of Mechanical Engineering, Nanjing University of Science and Technology, No. 200 Xiaolingwei Street, China ' School of Computer Science and Electronic Engineering, University of Essex, Wivenhoe Park, Colchester, CO4, 3SQ, UK

Abstract: In order to build the dynamic model of quadrotors with inner loop stabilisation system, a real-time system identification technique is developed in frequency domain with real flight data. Firstly, a second order transfer function is adopted as the low order equal system (LOES) for each channel. Then, a recursive discrete Fourier transformation (DFT) is detailed, which helps to calculate the recursive frequency spectrum of the inputs and outputs. Based on the latest frequency spectrum, the unknown parameters in LOES are calculated by a least squares method and then the observable canonical form of state space equations is given. Finally, the performance of the identified model is analysed in time-domain by calculating Theil's inequality coefficient and in frequency-domain by plotting Bode diagrams. The identified model is utilised for the design of tracking controllers. The experimental result validates the proposed method.

Keywords: discrete Fourier transformation; DFT; least squares estimation; system identification; quadrotor; path tracking; PID.

DOI: 10.1504/IJMIC.2017.086555

International Journal of Modelling, Identification and Control, 2017 Vol.28 No.3, pp.245 - 255

Received: 28 Jun 2016
Accepted: 20 Sep 2016
Published online: 12 Sep 2017 *

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