An Experiment on Closed-loop System Identification of UAV Using Dual-rate Sampling

Abstract

This paper reports on a closed-loop system identification experiment of an unmanned air vehicle (UAV) with the sampling period of the measured output being an integral multiple of the hold period of the control input. In more detail, the period of the control input of UAV is 5ms, while the position and attitude as the output of UAV are measured by a motion capture system with the sampling period 10ms. A dynamical model of UAV during hovering flight, which is an unstable system, is obtained using a dual-rate closed-loop subspace model identification method. The key point of our method is to apply a closed-loop subspace model identification method proposed by the authors, in order to obtain the so-called lifted model from dual-rate sampling data. Practical usefulness of our dual-rate closed-loop subspace model identification method has been demonstrated by the lab-scale real-life experiment.