Friday, May 16, 2014

June 1 Test

When I last entered the AVC in earnest, I remember there being an April 1 test, where you had to demonstrate the vehicle moving and steering under its own power and control. As it happened, I burned out my helicopter and shifted to the car design after this date, but I got a waiver when I demonstrated the car a mere 1 week before the contest. And we all know how that wound up.
April 1 test from last time, completed on April 17

So, I was expecting something like this, this time around. I was watching the Sparkfun web page, expecting to see something there. My phone automatically checks my gmail, so I was watching that. As it turns out, their email got stuck in a spam trap, and I didn't see it until today. So without further ado, I present the June 1 test, completed on February 22, 2014.
This test shows the steering servo connected to an Arduino Nano, powered by the BEC from the ESC, just like the real controller will be used.
Maya wants to help. Some tests are more successful than others...

This test shows the Arduino controlling both the steering and throttle.

Steering is the easy part. It is half of the Control function in the Guidance, Navigation, and Control triad. All the mechanical parts work and if the robot knew where to go, it could control itself and get itself there. The latter is the hard part. I anticipate using a Kalman filter with inputs from the GPS, magnetic compass, and inertial rotation rate sensor. I also am going to add a bumper, so in case it hits anything, it can back up and try again. This is to get around the barrels. I am not currently planning on using the line for line-following robots.

The parts breakdown is about as follows:

Robot chassis - RC car. Includes drive motor, steering servo, battery, ESC, and radio receiver (still carried in robot but disconnected). about $150. Maybe $100 if you count only the parts in the chassis that I actually use, not the receiver, transmitter, or battery charger.
Controller - Kwan Systems Loginator (Logomatic clone) - about $60
Inertial Sensors - Kwan Systems 11DoF - about $40
GPS - GP2106 - about $50
Miscelaneous wires and breadboards - scattered on my workbench.

After last time's debacle, I decided to not go crazy with parts this time. All parts except the chassis are from other projects. I have all these parts already. This is all the hardware I anticipate needing. I use lots of other parts for bench support, such as Arduinos, FTDI chips, oscilliscopes, logic analyzers, computers, etc. None of these are actually part of the robot.

As such, I believe it is a small enough budget that it might fit in the micro class.

As noted in the parts list above, I have chosen to go with the more powerful LPC2148, in the form of the Kwan Systems Loginator. You can read about the design of the Loginator and 11DoF further down this blog. I have repeated all these tests with that controller, but I didn't record them, and they would just look the same as these tests anyway. Video from those tests when it does something more advanced.

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