Home > General, Platform, Sensors > We’re In!

We’re In!

February 26, 2010 Leave a comment Go to comments

Today, I received the email from SparkFun.   Another team has dropped out so we are officially in!   Too bad for the other guys but I am happy for us.   The added pressure should ramp up the effort over the next few weeks.    So much to do, so little time….

Goodbye RC Control

On that note, work continues on the vehicle.   Today, I gutted the stock RC electronics.   Our current approach bypasses the RC receiver completely so I just removed it from the vehicle.   Traxxas did a pretty nice job of packaging the receiver and servo cable entry for water resistance/proofing.   But it had to go.

Next, an IR sensor was added to the rear of the vehicle mounted on the stock bumper.

Rear IR Sensor

Given the single sense beam, it is unlikely to be of significant help but should allow the motion planner to avoid ramming into something if the vehicle has to back up to get out of a cul de sac.   A little information is better than none at all.

I chopped up a little aluminum plate to fabricate a mount for the GPS sensor near the center of the rear axle.   Having it close to the point of rotation minimizes the need to do additional math to translate the actual position.   Simpler is better when it comes to calculations.    Once the paint is dry, I can get that installed

The encoder from US Digital should arrive on Tuesday.  By far, that will be the most complex to install and mate to the drive gear of the transmission assembly.  An accurate indication of speed is essential to being able to dead reckon between GPS updates or to handle GPS outages.    However, the steering will not have a feedback mechanism.   For now, the software will just have to trust that the set point is being achieved to determine steering angle and radius.    Not foolproof but should be sufficient.

Due to the battery compartment being only accessible from the inside of the vehicle, it makes mounting electronics difficult.  I’ll have to fab up something to allow access to the battery while still allowing the new electronics to be mounted and stable.    I should have dimensions from Floyd tomorrow when he returns from a trip so I can get that done.

In the interim, I’ll be continuing software development on our original prototype vehicle.

Prototype One

Prototype One

Floyd has already done the hard work on this vehicle but it lacks the new board plus the bulk of the sensors.   As you can see, we’re using XBee modules for remote telemetry and debugging.   Eventually, that communication will be quashed down to only a few control messages for mission execution and a remote stop signal.

Categories: General, Platform, Sensors
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