Works like model

We were finally able to build and test all of the working parts for our rover.

The car drives pretty well with all 6 wheels.  We initially based the rover off of the Sciborgs that we used earlier this year in order to create a working vehicle.  The rover is powered from the back two wheels since the Sciborg board is only able to support three motors at once and we wanted to save one for the arm/claw.  Since we will be incorporating hills into the landscape that the rover will drive through and we wanted to stay true to NASA's rover design, we also incorporated a third pair of wheels in the front.  These wheels will allow the rover to travel up steep hills and lower itself gently into ditches.

We encountered a few problems with this initial design.  For one, the rover didn't drive in a straight line, a problem that was prevalent throughout the Sciborg project.  Another issue was that the rover was unable to drive up steep hills because of a protruding back piece that the Sciborg design incorporated.  We thought this back piece would be a cool way to prevent the rover from damaging itself if it ever backed up into anything.  However, it just hindered the movement of the rover in the end.  There were also extra pieces and structural parts that could have been built in a more efficient way.  Thus, when we iterated the rover, we removed the back bumper piece and redesigned some of the structural pieces, especially near the front two wheels.  After this iteration, the rover drove in a straight line and the back was no longer a problem.

Initial design Rover stuck

Initial design Rover

Sciborg that we based the Rover off of

Our second big component was the robotic claw.  Our goal is to incorporate this feature such that it will be able to pick up an object of our choosing.  Since we are using a motor, only one side of the claw can move.  Thus, we chose to make it the bottom jaw since the top does not need to move as much.  We plan on making this feature in delrin so our initial testing was focused more on creating the structure and code that would allow the claw to move successfully.  We also noted that if the claw were placed on the back, it would pose a problem when the rover drove up the hill.  Thus, we attached a small piece that would push the upper jaw upwards when the lower jaw encountered a steep slope.  I foresee this feature being replaced when the actual delrin pieces are created since there will be solid walls that can push on each other.

I forgot to save the code that we used to power the claw.  However there are two simple commands:

OpenClaw: Talk to c, set power = 40, motor on = 8 sec

CloseClaw: Talk to c, that way, set power = 40, motor on = 8 sec

Rover after iteration that incorporates the claw

 Protruding piece that pushes the upper jaw up