Performance assessment of an energy harvesting system located on a copter

A Koszewnik,D Oldziej

doi:10.1140/epjst/e2019-800128-3

Abstract

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.

Highlights

Energy harvesting from moving structures for autonomous electrically powered applications, i.e. unmanned aerial vehicles (UAVs), especially in the case of multiple motors like a quadrocopter, is a common subject of scientific in vestigationin last years
For this purpose taking into account parameters of input power of the system dedicated to power supply of the copter (Vin = 14.7 V, Iin = 4 A for 40% of the duty cycle of the Pulse Width Modulation (PWM) signal applied to BLDC rotor with propeller) and output power can calculate efficiency of the system in the following form: ηele
The aforementioned fields of applications caused that such kinds of mechanical structures have been a subject of many articles in recent two decades. This caused that our investigations are focused on determining distributed parameters of a piezoelectric harvester located on a single arm of a UAV six-rotor and check the possibilities of the considered structure to harvest energy

Summary

Introduction

Energy harvesting from moving structures for autonomous electrically powered applications, i.e. unmanned aerial vehicles (UAVs), especially in the case of multiple motors like a quadrocopter, is a common subject of scientific in vestigationin last years. This caused that the electrical circuit of the system can be obtained by substituting the electric field Both equations (1) and (5), refer to distributed electro-elastic model parameters of the piezo-patch harvester integrated to a 1D mechanical structure in physical coordinates. The performed considerations of the cantilever beam with an integrated piezoharvester for modal coordinates allow to calculate the value of rectified voltage response accumulated on the resistorR in the steady-state For this purpose, assuming the harmonic form of the force generated from the system connected with the motor BLDC and the propeller, formed as f (t) = F0 sin(ωt) = F0ejωt, the modal voltage response V (t) and the modal response of the system ηn can expressed in the following forms:. The frequency response function of the modal voltage amplitude Vof the smart beam in the frequency domain can be express in the following form in the case of substituting equation (16) into equation (15) [13]: xPH 2

Numerical analysis of a single smart arm of the UAV with a BLDC rotor

Experimental set-up and testing of energy harvesting system

Findings

Summary and conclusions