Robotics: Our Homemade Unmanned Ground Vehicle (UGV): A New Direction
Posted on 2008-11-18 @ 22:13:54 by r00t - Read the parent: A Remote Operated Vehicle (ROV) Project

Well, it's official: I am going a new direction in the development of the UGV. A friend from my work, Jared Hurn, has decided to assist me in the development and programming of the robot. We hope to eventually be able to enter it into the Robo-Magellan contest, if not the one next year, then the year after. Read on for more about this exciting new direction the project has taken!

Jared Hurn brings to the project a knowledge of GPS coordinate and spatialization mathematics, along with other skills related to UGV and ROV tasks. He is also highly interested in learning about machine vision processing, along with neural network systems; both of which are skills necessary to know for advanced robotics projects, even at a hobby level. His addition to the team will make the development of the UGV project proceed at a much quicker pace.

I now present several videos I have taken of the UGV's embedded computer system we are developing. As you may remember (and if you don't, read the parent for more information), the UGV is being built around a scale R/C truck. Our embedded computer system, as you will notice in the following video, is larger than what the truck can carry (and power!):

So - why are building this system?

Well, it was never my intention to stop the UGV development after the completion of the truck and its controlling software. Ultimately, I had planned two additional stages (the third is kinda "pie-in-the-sky" - here's hoping we actually manage it!):

  1. This stage is where we are now, with the scale truck chassis.
  2. This stage was to scale up from the truck chassis, and utilize a PowerWheels platform.
  3. Fantasy stage: Quad ATV, large go-kart, or custom 6-wheel chassis, possibly with hybrid gas/electric drive.

So, for the first stage the embedded system will act as our controlling platform for the scale R/C truck. By setting it up so that we communicate with the embedded box using an 802.11g WiFi connection, we can connect via a browser (and https) to an on-board Ubuntu LAMP-based web application which will send serial commands via an RF-serial link to the OEM Basic Stamp 2, which serves to command the pan/tilt camera servo platform, the drive and steering motors, along with other on-board devices. Essentially, the brains stay stationary while the body is controlled from a distance.

While this initial platform and software is developed, other work can be developed for the future system, which will include a high-resolution web camera mounted to the pan/tilt system for telepresence and recording, along with research and development of a vision processing system for autonomous navigation (coupled with on-board GPS and other sensors). Then, once we have exhausted our options with the R/C truck platform, we can move on to the larger platforms and have our system ready ahead of time, in a sturdy and protective casing.

The following videos show how I made a custom bracket for mounting the 802.11g WAP circuit board to the ATOM motherboard. Prior to the building of this bracket, Jared had attached an SMA connector to the antenna wire of the WAP (it didn't originally have a removable antenna). Once the WAP was attached and the rest of the machine assembled, I booted it up to verify that the power connections worked:

Since these videos, we have continued work on the system in a variety of tasks. For one, I have been developing the code to allow the server to control the servos and other items on the R/C truck. We have also found that the lid-mounting of the hard drives was a mistake; we didn't realize that the SATA connectors couldn't handle the strain. We intend to move the hard drives to a better location (near the fan), and keep them oriented parallel with the SATA connectors on the RAID adaptor.

We also (well, Jared, actually) secured a PowerWheels Hummer H2! So, we have our second stage platform, and we haven't even finished the first. However, I think we got a good deal on the purchase; it had a working battery and charger, and the thing is plenty powerful (my 240 lbs didn't even slow it down when I rode on it)!

We are also investigating building a cheap structured light LIDAR/LADAR system to help with the vision processing system. We will be basing it around the high-resolution web camera we purchased, and use a red or a green laser, along with a cross line generator lens and a radial or square diffraction grating to project a grid onto the terrain from which we can synthesize distances from. At least, that's the idea...

I hope to have articles in the near future about these developments. Stay tuned, and enjoy the videos!

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