Stationarity of electromechanical propellers variables: a unit root test approach

Valid mathematical models can be obtained by the means of the system’s input and output data, as well as by using system identification techniques. However, it is fundamental that the data within the time series does not violate the statistical assumptions of the series. It is necessary to perform tests to detect possible violations of the system’s variables. Concerning the time series of the experimental data, the present work investigates and performs three stationarity verifications tests on the data series: the ADF test (Augmented Dickey and Fuller); the PP test (Phillips and Perron); and the KPSS test (Kwiatkowski Philips Schmidt and Shin). Electrical current and angular speed data of an electromechanical propeller were collected for the testing by the means of an experimental platform. The propellers utilized are those of Unmanned Aerial Vehicles (UAVs). This work’s contribution consists in establishing pathways that allow obtaining non-spurious mathematical models that represent the physical model with reliability.