Interview with Ben Coughlan

Featured Engineer

Ben Coughlan

Ben Coughlan - PhD Scholar, The Australian National University; Consultant/Engineer, CGSY

How did you get into electronics/engineering and when did you start?

My interest in electronics can go back as far as playing with “Funway into Electronics” kits from Dick Smith. My background since then has been mostly software. I completed my Bachelor’s degree in Software Engineering at the Australian National University in 2009 while working at Codarra Advanced Systems.

After getting a taste for embedded software development on a few projects, I jumped at the chance to return to university to complete a PhD focused on Unmanned Aerial Vehicles. So far this has taken me well outside of my software comfort zone involving a lot of electronic and mechanical design.

How do you find working in other disciplines given your software background?

I touched on a number of other disciplines during my degree including basic electronics and mechanics. The things I find most useful are the abstract concepts required for systems engineering. These concepts are very familiar after learning about software architecture and design.

When I approach a new discipline, it’s easy to map the required system knowledge. It’s then just a matter of learning the specifics of design and implementation for what I’m trying to build.

What are your favorite hardware tools that you use?

The tool I use most often would easily be my callipers. Simple yes, but whenever I need to build a model, which is pretty often, my callipers are invaluable.

I should probably also mention my cast-iron frying pan. It’s the easiest way for me to reflow a board with surface mount components and it makes pretty great pancakes.

What are your favorite software tools that you use?

I think my two favorite pieces of software would be Altium Designer and Solid Works. Between these two products I can design and model just about everything I want to build. Being able to create virtual prototypes is invaluable when money for physical prototypes is hard to come by.

What is on your bookshelf?

There are a lot of textbooks. The two most relevant/recent additions are Feedback Control of Dynamic Systems by Franklin Powell and Probabilistic Robotics by Thrun, Burgard, and Fox.

On the fiction side I’ve been enjoying the Book of the New Sun series on audio book. At the moment I’m listening to Catch-22.

Do you have any tricks up your sleeve?

Nothing specific. My usual approach always involves doing things the hard way, or from scratch myself. Often I learn why I shouldn’t be doing it myself from scratch but it does leave me with a better understanding of how something works. As the quote goes: “Aim for the moon; even if you miss you’ll land among the stars.”

It always helps to surround yourself with people that know things. I’m lucky to have experienced colleagues that can easily answer all my silly questions. Otherwise I can always turn to online forums. It’s important to involve yourself and your work with the world.

Do you have any note-worthy engineering experiences?

My most noteworthy accomplishment would be an award for innovation my team and I won in 2009 at the Australian National iAwards for a software framework supporting the development of robotic applications on Linux platforms.

The Linux Robotics Framework was my final year project for my Bachelor’s degree. I managed a team of five other students to produce the framework for our sponsor Nias Digital. The framework was intended to provide a collection of software components and accompanying design concepts to simplify the development of robots running Linux. This included a hardware abstraction layer with drivers for a few interface devices like the Pololu TReX motor controllers and serial servo controllers, as well as some higher level functions like steering, throttle, and a controller for a 3 DOF arm.

We built a robotic vehicle named ‘Buzz’ as a demonstration for our project. Starting with a 4WD RC truck we constructed a chassis to mount the extra hardware we wanted. This included a pan/tilt CMOS camera, a 3DOF arm with a gripper, various controller boards and transceivers for 2.4GHz wifi and video. The main processor was a 32bit AVR on an Atmtel NGW-100. This was a conveniently sized, low powered board that our sponsor was using at the time.

More recently, the first prototype of Asity, the avionics board I’ve developed, came off of the frying pan and actually worked on the first try. It being my first significant electronic design, I was pretty happy with this.
h5. What are you currently working on?

My PhD is investigating energy usage in unmanned aerial vehicles. The goal is to monitor energy levels and consumption onboard the aircraft in real time and try to develop behaviors that optimize these.

Including solar and wind energy, I hope this will lead to extreme-endurance aircraft that maintain the capabilities required in the growing UAV industry.

Can you tell us more about your UAV research and projects?

My research is investigating the energy usage of onboard UAVs. This includes monitoring the total energy stored in the system, including the aircraft’s velocity and altitude, in addition to the battery. The goal is to develop flight behaviors that optimize energy usage in reaction to air conditions and energy inputs (e.g., solar). In suitable aircraft or use cases, this will hopefully increase the endurance of the system. Simply put, I would like to show that the most efficient behavior for an aircraft is not necessarily straight and level.

This is a highly experimental project so I have had the opportunity to develop many custom hardware components. The main avionics is a custom board I’ve named Asity. This is a processor, inertial sensor pack, and radio in a small package to fit in the slim fuselage of the gliders I work with.

The main processor is actually an FPGA to allow for high integrity, interrupt-free, and flexible design of the avionics firmware. FPGAs are notoriously power hungry, so I have used the Actel ProAsic3 series of chip. Being flashed based, in contrast to their SRAM based competitors, they have a much lower current draw and don’t require any configuration memory. The current Asity prototype has 1M system gates; time will tell if this is sufficient. I am avoiding soft-core processors for as long as I can, and I believe I can build a complete avionics system in HDL.

While I’m developing an experimentation platform, I’ve decided to include capabilities for the Outback Rescue Challenge. I hope to compete in 2012 with my 4 meter glider.

What has been your favorite project?

My current one, hands down. I was into model aircraft as a kid and now I get to play with them for a living. Given this is a research project, I enjoy a lot of freedom with what I work on.

What direction do you see your business heading in the next few years?

I still have a few years in the comfort of academia. Between now and then I hope to develop something that can support further research. My main goal is just to keep working on the same or similar projects.

What challenges do you foresee in our industry?

The biggest challenge in the UAV industry specifically is mostly legislative, although this is driven by quite reasonable, technical short-comings.

Aircraft are not currently permitted to fly truly unmanned without constant supervision from someone who can take control. This does limit the range and utility of such aircraft.

The challenge for engineers in this field is to develop systems that are safe, reliable, and capable of sensing and reacting to abnormal situations.