System Identification and Modeling of an Actuation System for Small Aerial Vehicle

System identification develops a mathematical model of a dynamic system from the observed input and the measured output data. It is very important for a successful control application. This work proposes a method for Unmanned Aerial Vehicle (UAV) servo system identification. The classical method that was being used to identify the actuation system was based on using a potentiometer connected to a microcontroller. The potentiometer is usually fixed on the servo so the value of the potentiometer reading is equivalent to the servo angle. The mathematical model is generated using MATLAB system identification with the PWM value as input and servo angle (which is indicated by the potentiometer) as output, the generated model is not depending on the actual configuration of the actuation system as a whole. This paper will generate the mathematical model taking into account the length of the servo horn, the pivot point on the control surface, and replace the potentiometer used by the classical method with the actual control surface. The proposal uses a commercial gyroscope calibrated with turn table to find the actual angle of the control surface, unlike the classical method which measures the servo angle. MATLAB simulation is introduced and the results show an improved model compared to the classical method which uses a potentiometer on the servo itself. The simulation results are presented for the first-order and the second-order transfer functions.