UWE Bristol Engineering showcase 2015

Andy Lang
MEng Aerospace Systems Engineering
Project Supervisor
Pritesh Narayan
The Design of a Tri-Rotor UAS Optimised for Forest Fire Surveillance
Background
Unmanned aerial vehicles have been utilised in a
variety of natural disaster data acquisition tasks for
over a decade, predominantly in post disaster use.
The type of disaster environments that the
technology has been deployed ranges from
hurricanes, earthquakes and tsunamis. Although a
great deal of the platforms were envisioned to
assess the severity of the natural disasters,
offering video footage from various angles
unobtainable by other methods, some were used
to provide detailed evaluation in critical
environments.
Practical Analysis
All Tri-Rotor manoeuvres refer to the thrust force
generated by each rotor through manipulation of
their individual speeds. The relationship between
the thrust force and the rotational speed is a
complex one which takes into account various
elements in the powertrain design. A thrust
analysis was performed on multiple propellers.
CFD Analysis
To further assess the validity of the results, a CFD
analysis was implemented to add another
dimension to the investigation. In order to achieve
this, the motor and propeller assembly was
modelled in SolidWorks in a simplified manner.
These were then put through a simulation and
compared to physical and theoretical results.
Design and Build
The MK-III Tri-Rotor below was rapid prototyped
and assembled in 24 hours, after previous versions
outlined prospective areas of improvement. The
final UAS is incredibly stable and has a flight time
of up to half an hour and is fully capable of First
Person View (FPV) flight.
Further Work
One of the main decisions for selecting a Tri-Rotor
airframe was because of the theoretical endurance
supremacy over other Multi-Rotor systems.
However, as the study has progressed the
underlying theory has been identified to have
sources of error which could have led to an
inaccurate decision. Therefore, the development
of the Quad-Rotor system illustrated is currently
underway to compare the endurance of each UAS
in a practical assessment
Project summary
The primary aim of this investigation is to design a
UAS capable of undergoing the task of monitoring
forest fires in Ontario. The system is a combination of
a stable Multi-Rotor platform which facilitates the
desired flight characteristics, and a sensory payload
which is essential to perform the desired task. The
investigation is a result of encompassing various
research objectives and fabricating an efficient design
capable of achieving positive results in the scenario
set by the Ministry of Natural Resources, Aviation
Forest Fire and Emergency Services, Ontario.
Project Objectives
• Perform a Thrust Analysis
• Undertake a Hardware and Sensor Selection
Process
• Design, Build and Test a Tri-Rotor UAS
• Fly a Mission Demonstration
Project Conclusion
An investigation into the design of a Tri-Rotor UAS
utilised for a particular flight scenario has been
conducted and specifications have been established
to define necessary flight characteristics. The
majority of the project at this stage has been driven
by research, both through a literature survey and
exploration into a wide focus area. The prerequisite
knowledge of rapid prototyping from Part A of the
project helped fuel the iterative design process of the
Tri-Rotor facilitating the opportunity to explore new
applications within the field and exploring valuable
experimentation potential. After acquiring a
perception of the wide subject area of Multi-Rotor
remote sensing platforms and how their synergies
between functionality and flexibility benefit the
design process, the theoretical and practical
assessments could be recognised.