Ultrasonic Rangefinder Spikes Rejection Using Discrete Wavelet Transform: Application to UAV

Ayman El-Badawy,Ramy Rashad

doi:10.4236/jst.2015.52005

Abstract

This paper presents a spikes removing methodology for ultrasonic rangefinders with an application to a quadrotor unmanned aerial vehicle. Ultrasonic sensors suffer from spikes in distance measurements due to specular reflectance and acoustic noise. Removing these spikes is necessary for improving the hovering performance of the quadrotor. The spikes removing algorithm is based on the discrete wavelet transform. The algorithm is implemented in simulation to study the effect of the altitude measurement spikes on the control performance of the quadrotor with and without the algorithm. The algorithm is also implemented digitally on ultrasonic measurements from a real flight. Results show that the method is capable of rejecting the spikes in the measurements efficiently leaving the altitude control signal unaffected.

Highlights

The field of aerial robotics has evolved in the past decades due to the rapid advances in sensors, computing and other technologies
To study the effect of these spikes on the control performance, a simulation study was performed by a developed simulation environment using MATLAB
A simulation run was performed to show the result after applying the spikes removal algorithm which is shown in figures (Figure 5 and Figure 6)

Summary

Introduction

The field of aerial robotics has evolved in the past decades due to the rapid advances in sensors, computing and other technologies. When equipped with appropriate sensors and control algorithms, they have the potential to provide cost-effective solutions to many indoor and outdoor applications. Their main advantage over other types of UAVs is its simple mechanical structure and fast dynamics that allow them to perform aggressive maneuvers. (2015) Ultrasonic Rangefinder Spikes Rejection Using Discrete Wavelet Transform: Application to UAV. The wavelet transform has an advantage over the Fourier transform in its ability to produce temporal resolution i.e., it captures both location in time information and frequency information It has been a suitable candidate for applications in numerical fields [1].

Dynamical Model and Controller Design

Discrete Wavelet Transform

Simulation Results

Experimental Validation

Conclusion