Test Rig
January 4th, 2008 by 
David
I recently started assembling a test rig to integrate all of the electronics that will be going in the UAV. By performing all of this integration on test bench, the final installation and configuration will be performed much faster. This will also allow us do our HIL (Hardware In the Loop) simulation with all of the components connected.
You may have noticed that there are two large NiHM battery packs, these will soon be replaced by two (11.1V 3200mAh) Lithium Polymer battery packs, saving us about half a pound of weight and significantly increasing our power capacities. Although for bench testing all of the electronics will be powered of off a standard ATX computer power supply. The next step is the get the HIL simulation working with the autopilot and the it’s simulator, this part has been a bit finicky but it should be resolved now.
As a team we have also discussed possible strategies for image acquisition and processing. We had previously planned on simply acquiring VGA resolution video at 30 frames per second, but after reconsidering what altitudes we will be required to fly at to cover the search area in a reasonable time we quickly realized that VGA video would not provide the resolution we need to identify a human target on the ground from an altitude of 400 feet. We have since decided it would be best to use a much higher resolution still camera taking images at set intervals and tagging them with the GPS coordinates and the orientation of the UAV.
Posted in Autopilot, Electronics | 
5 Comments »
April 2nd, 2008 at 4:41 pm
I am a student at UCSD working on a multi-UAV project and am looking at the Kestrel autopilot for our system. What are your thoughts on the hardware quality/durability? Have you noticed any excessive latency issues while controlling the aircraft in manual mode? Are you using the servo extension board provided by Procerus?
April 3rd, 2008 at 7:40 am
So far I have been impressed by the system overall. I found the software and documentation to be very good, and if you ever have any trouble they have great support. The hardware is also quite durable, it survived one of our crashes so that was good, and we haven’t had any issues with reliability.
I have heard of people complaining about latency issues when not using the Maxstream (or now Digi) Xtend serial modems, but with the Xtend modem it has been working great for us, the latency is noticeable (I think it’s around ~10-20ms, you can contact Procerus for exact numbers) but very manageable, our pilot has not had any problems with operating it under manual mode. We are currently not using the servo expansion board so I don’t have any first had experience with that, but we do plan on adding it shortly.
I would like to hear more about your project, do you have a website?
Thanks,
David
April 3rd, 2008 at 11:08 am
We are working on a multi-UAV system for sensor development to effectively monitor plumes from a variety of different sources. No website for this project has been created yet. Once I have one up and running I will post the link here.
May 6th, 2008 at 4:17 pm
I have a question regarding the Aviones program used for the hardware in the loop simulation. Where did you get the data to modify the physics library so that it was simulating your specific aircraft?
May 6th, 2008 at 11:03 pm
We did not actually use the physic parameters for our specific airframe. We primarily used Aviones to practice what we will be doing at the actual airfield with our airframe in order to speed up the tuning process. We also used it to play around with the navigation parameters and to just get familiar with the platform.
The aerospace engineers on the team told me that we would have to model the entire aircraft in order to get the moments of inertia of the aircraft and then you would have to know all your wing and control surface parameters; you would then enter all of these parameters in the physics file. But I am not too familiar with the process, you might try contacting Procerus to see if they have any suggestions.