Performance assessment of an energy harvesting system located on a copter

Energy harvesting from moving structures for autonomous electrically powered applications, i.e. unmanned aerial vehicles (UAVs), especially in the case quadrotors, has been a common subject of scientific investigations in last years. Most of them have looked into improving the endurance of electrically powered UAVs using technologies such as photovoltaic or vibration harvesting. UAV platforms have a limited amount of power for electrical suppling. In order to keep a constant time of flight duration, the UAV can be equipped with an additional battery, which increases the total mass and causes higher energy losses. Therefore, we address this problem in our paper by proposing a vibration-based energy harvesting system. It consists of piezoelectric harvesters integrated into a frame of BLDC rotors. In order to check efficiency of the energy harvesting system, the copter is equipped with MFC harvesters. Taking into account this solution, the distributed-parameters of the electromechanical system in the modal coordinates are estimated using numerical methods. The simulation results showedhow the duty cycle of the PWM signal applied to the BLDC rotor and resistive load connected to the system influence on voltage generating by the piezo harvester, while experimental test allow verify them.