Project #2 - Team Chassis Design and Fabrication

In this project, your team will complete the design and fabrication of the chassis for your robot. It is strongly recommended that your team meet before lab session to block-in a design, that way, fabrication can be completed in one lab session.

Although we won't be extinguishing flames, your robot must comply with Trinity rules regarding vehicle geometry and will compete in three challenge tasks: (1) the Precision Challenge, (2) the Maze Challenge, and (3) the Long-Range Speed Challenge. Your goal is to fabricate a chassis with motors and wheels for a differential steering/drive and a caster concept that allows the robot to move and turn---possibly go up and down a shallow ramp. Care must be taken to plan the overall size and layout of the vehicle. It must specify the Handyboard or the Arduino as an Embedded controller and include swapping batteries for recharging, enough area to accomodate peripheral sensors and actuators, and a cabling concept for connecting future subsystems to I/O. Be aware that you may want a more advantageous gear ratio for the Speed Challenge and you should try to make your design capable of accomodating pulleys and belts between the motors and the wheels at a future date.

You will also write your first embedded control application. This very simple code will drive the motors so that your robot executes open-loop circular patterns. Your robot should execute counter clockwise circles of varying radii. The turn radius should be specified by the potentiometer knob input on the HandyBoard.

This is the first team project. One team (electronic) notebook should be submitted per team and should be clear from the outset about what will be done and who is doing what.
Materials:
  • perf board chassis - possibly multi-layered with standoffs
  • 2 - motors (larger motors with gearboxes), they're slow but they'll go up hills
  • 2 - motor brackets
  • HandyBoard/Arduino
  • stranded ribbon cable for fabricating motor cables to PWM outputs.
  • 2 - wheels and a caster.
Report (one per team):
  • a short verbal description of the design concept, including a diagram "as built" and the concept as it might look when the whole robot is done---guess.
  • experimental evaluation of the open-loop controller at two important turn radii: zero, and approximately 10 cm. Have the robot execute 10 circles at these radii on a piece of paper and record the approximate position of a reference point on the robot each time it returns to its initial heading.
  • a brief description of these results (mean and variance).