Simon Howroyd
  • Male
  • Loughborough
  • United Kingdom

Simon Howroyd's Discussions

Antenna Tracker v0.1

Started this discussion. Last reply by Charles lakins Oct 10, 2014. 4 Replies

I notice mission planner has "Antenna Tracker v0.1" in the firmware list. Anyone seen documentation for this? I seem to be struggling to find anything.CheersSiContinue

Tags: tracking, antenna

Reversing deflections

Started this discussion. Last reply by Søren Kuula Apr 24, 2014. 2 Replies

Hi all,I'm sat scratching my head trying to do something which is easy on APM...My PX4 is all set up and working...however, in seatbelt mode, the autopilot actuation is reversed for the elevator and…Continue

Tags: PX4

PX4 Pressure Sensor for Airspeed

Started this discussion. Last reply by Simon Howroyd Apr 8, 2014. 2 Replies

Hi all,I need an airspeed sensor for my PX4. According to the documentation, this is an analogue sensor (…Continue

Tags: differential, pressure, airspeed, PX4, Loughborough


Started this discussion. Last reply by Tom Pittenger Jan 12, 2015. 9 Replies

Hi All,I am struggling to find any concise information on ArduStation, but bits and pieces I can find suggest it is a pretty handy bit of kit that I might consider exploring...My main intent it to…Continue

Tags: University, Loughborough, FuelCellUAV, ArduStation

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Efficient Powerpath Balancing for Fuel Cell Battery Hybrid Powertrains

Posted on February 8, 2016 at 6:13am 15 Comments

For those following my work, thank you and sorry for the long wait for an update!  I am currently writing up my doctorate so as you can imagine I have been a social hermit recently!

Nevertheless, I have now had a journal paper published which may be of interest to those fellow electronics geeks out there and as a bonus it…


Loughborough University Undergraduate Search & Rescue

Posted on April 29, 2014 at 1:00pm 9 Comments

Undergraduates of Loughborough University have to do a Group Design Project as part of their final year Aeronautical MEng degree. This year, with the help of Simon Howroyd a PhD student at the University, one of the groups were challenged to design and develop a UAV capable of searching for a…


Hydrogen Fuel Cell Polarisation Curve

Posted on January 16, 2014 at 8:30am 12 Comments

Hi all,


The latest update on my project for the chemical engineering nerds out there, how to get a polarisation curve from my fuel cell using a raspberryPi controller.


Why a fuel cell; if you haven't followed my other posts, they can provide cruise power for hours, greatly increasing the endurance of a RC plane or…


Long Endurance Flying Technology Prototype

Posted on December 20, 2013 at 11:00am 16 Comments

Please see the video below for a description of my fuel cell controller (so far) for a remote controlled plane. A fuel cell provides much greater energy density than a battery, so for long endurance it is far superior (hours). Hopefully, with a bit of refinement I'll have the system flying in my SkyWalker X8 in the spring.

 Feel free to comment, I look forward to sparking some interest!




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Fuel Cells in Unmanned Aircraft

This project is researching and developing, the implementation of a hydrogen fuel cell into a small autonomous unmanned aerial vehicle.

The aircraft will be a development platform for the integration of a Horizon 100W hydrogen fuel cell, along with the development of eco power management to increase endurance.
Using ArduPilot Mega 2.5 and a RaspberryPi with WiFi dongle, flight and power data can be obtained and transmitted in real time to a laptop, over a network or the internet.  The system can also accommodate a webcam (to be upgraded to a GoPro 3) and stream all this data on a user friendly webpage.
Try the first link below for my YouTube channel, the second link for the code:

Latest Challenges

Overweight testing of the X8 has begun. A few modifications include a larger prop 16x8" folding and fiberglass tape on the lower wing. Flying at 5.6kg very well, next stage to push towards 6kg!
Calculations on wing loading done by Robert of NuvAero Flight Systems give promising leads to the capabilities of the X8:
X8 has 80 sq. dm of wing area. Lets compare it to the popular Gatewing X100 which is 23 sq. dm. Gatewing is 4.4lbs so has a wing loading of 31.5 oz/sq. ft. Cruises around 75km/hr and reported stall speed of 45 km/hr.

Our X8 at 8.5lbs has a wing loading of 15.8 oz/sq. ft. At 9.9 lbs it would be 18.5 oz/sq. ft. In fact our X8 would need to weigh 16.8 lbs to have the same wing loading as the Gatewing.

I'd say that at 8.5lbs it flys great. Could easily handle a couple extra pounds as far as flight characteristics go. Would consider proper carbon fibre wing spars and maybe some fiberglass packing tape first.
Watch this space for results!

I am also in need of peoples flight data; I need current, voltage and throttle for any flights you do, which I can include in my PhD research. Inbox me if you can help!

Any advice, experience or ideas please let me know!

Current Setup

  • SkyWalker X8 Airframe
  • ArduPilot Mega 2.5 Autopilot
  • Spektrum AR12010 12Channel DSMX Receiver
  • Hyperion ZS-4025-10 505kV motor
  • 16x10" non-folding 2 bladed propeller
  • Hyperion Titan 85HV Opto PO31 ESC
  • Hyperion G3 CX-25C 4000mAh 7s LiPo Battery
  • Hitec HS7965MG Servos
  • Spektrum DX8 Transmitter


The X8 has successfully flown at 5.6kg. It flew well, however upon landing (on long grass) the main spar snapped. I have fitted a new spar and have also fitted plywood plates in the wing root (there is already a recess in the X8's design for this).
I have also made good progress on the code for the fuel cell controller, which is available on github. I'm also using MAVProxy to save all the flight data onboard and transmit it to the ground over WiFi at the same time.

Older News

The X8 has successfully flown at 4kg, rocketing into the sky with no issues. I have also now finished t

he fist prototype of my hybrid power setup, which will eventually see the raspPi take over from the Horizon controller to manage the whole system. And, of course, the various components will be condensed onto a single breakout board rather than wires & bits everywhere!

All suggestions for improvements welcome!

Older Older News

In order to take such a high weight I have beefed up the structure using fiberglass tape. I am also running a 4Ah 7s LiPo with 1800W motor (needs to be a high voltage for fuel cell integration). Currently I am running a smaller 12x7" prop which stalls if much above 50% throttle, stopping torque roll completely. I will up the prop as I increase the weight.

The X8 has now flown! Cruising around on 20% throttle on the first flight. I shall be doing some more flights (weather permitting) and collecting some data & video.
All-in-all this is a very impressive aircraft, currently weighing in at 2.72kg including about 500g of ballast.
I've also got the raspberry pi transmitting a nice HD webcam with low latency (~0.25s) and about 15fps!

I have successfully moved from using XBee to connect our vehicles together and to the ground, and have replaced them with a WiFi network.  It could be set up as an ad-hoc network, but for development I am using a standard home router to host a wireless-g network, which my laptop with mission planner connects to, as do our vehicles, at the full 54Mbps (less errors than 100Mbps).  This is 100x faster than the XBee's, and in testing has proved to have a better range and signal quality.  Below is an image showing the new setup, and how "plug-and-play" it is.  I have no experience of networking but this was very easy to set up in 30mins.

Much Older News

I have now received ArduPilot Mega 2.0 (APM2), a full autopilot suite for model aircraft.  This has a 6DOF accelerometer/gyro MEMS sensor, static and dynamic pressure, GNSS (GPS) and a magnetometer (compass).  Is can be used in pass through mode (manual control), fly-by-wire for automatic stabilisation and autonomous for waypoint following.  It has 2.4GHz telemetry to communicate with ground station software on my laptop, where missions can be updated in flight!
This has now had three flights, all successful!  It is heavy, requiring 60-70% throttle to cruise in wind.  I have tuned the low level stabilisation gains allowing for carefree handling.  Airspeed hold is proving to be more difficult for FBW-B mode, so when the weather perks up I will go straight for autonomous circuits with me commanding throttle!



Profile Information

About Me:
Love flying fixed wing aircraft, primarily electric but I was taught on glow.
Please tell us a bit about your UAV interest
Autonomous Systems Specialist
Hydrogen Fuel Cells in Unmanned Aerial Vehicles

Comment Wall (11 comments)

At 11:59am on March 20, 2013, Tommy Larsen said…


What is your X8 weight before you put the batteries in ? 

At 1:03pm on March 20, 2013, Simon Howroyd said…

The operating weight empty, everything except batteries, is 2.3kg. The rest is made up of a 4Ah 7s Hyperion 25c LiPo (~350g ish I think) and a load of dummy weight.

My goal is to put an expensive fuel cell, so at the moment I'm testing it with buts of junk inside to simulate the weight.

At 2:18pm on March 20, 2013, Tommy Larsen said…

Ok :)

I have been looking into FC myself. I have seen the H-100 and also this one :

At 2:41pm on March 20, 2013, Simon Howroyd said…

Ah cool. I'm using the horizon h100...because that's what I was given lol.

At 1:45am on April 3, 2013, Tommy Larsen said…

Hi Simon

How is your overweight testing at 6kg going ? :-)


At 1:26pm on December 20, 2013, Michael Cook said…

At UAF we fly UAV's for many different research projects. A lot of the time our flight times are small because of the battery. We are looking for ways to fly longer times and we know that fuel cells are the way to go! Some of our sensors that we fly are around 500kg. But we need to fly longer. Somethings I think we are work on is how does a fuel cell handle in extreme cold climates. I have access to some of the coldest places in Alaska with temperatures down in the -50F. We think that coming together with other Universities is way more beneficial then giving some big name company thousands of dollars. You gain knowledge along with it. I think the biggest question here is what progress have you made and is it something that could help us out a lot. 

I hope that I have answered your question. As I believe it will be really great work and very beneficial in the future to tell people about this type of technology flying in UAV's today. 

Thank you for listening and your time. 

Michael Cook

At 6:38am on January 25, 2014, Eye-in-the-sky said…

Hello Simon

I have been following your works on the hydrogen cell and am about ready to go into that subject. Are there any 'Tips' that you can share and also do you have a schematic wiring diagram for your 100W system? Thank you.

At 3:00am on January 27, 2014, Eye-in-the-sky said…

Thanks Simon. I shall study the info you sent me. Have you flown this with an APM without the Pi?

At 9:25am on March 24, 2014, Keith Geary said…

Hi Simon,

I have sent you a PM regarding the LMFC.



At 9:28am on October 29, 2014, Chieme Nicholas Olisakwe said…

hi simon

i bet you are a great guy. please i have a question for you, how do i connect the APM2.6 to the pi, i mean the pin connection?

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