RoboCupMechanical2008

This page houses the current RoboCup Mechanical efforts. The 2007 efforts can be found here. All development work will be done in Autodesk Inventor 2008. How to use Inventor and get it can be found on the Inventor How to Guide. Inventor is also available on our CAD Machines in Tin.

Mechanical team meets Monday at 7pm and after the general meeting on Thursdays at 6:30

Systems

• Drivetrain
  • Omni Wheels
  • Motors/Gearing
  • Drive Module
• Integration
  • Shell
  • Chassis
• Ball Control
  • Dribbler
  • Kicker
  • Chipper
• Test Rig

Schedule

• To be updated when testing plan is more developed
• Nov 14th - Full design review
• First of spring semester '08 - robots designed and assembled

• October 24th - First prototype of ball control system - at minimum Dribbler and Kicker.

Meetings

• 9/6/07 - Update for new members, organized testing plan and ideas
• 9/13/07 - Organized most of the required tests into one device that will be designed starting on monday when we get CAD computer's back in the TIN.
• 9/20/07 - The Test Rig aka "The Everything Box" is being designed and components spec-ed out. The hunt continutes for the dribbler motor.
• 9/24/07 - Everything Box still being designed, would like to start ordering parts on Monday 10/3/07. Idea generation started on the dribbler system such as suspension and damping systems
• 9/27/07 - Test Rig nearing completion. Concepts of ball control system discussed as well as the use of solenoids or some other actuator for the kicker

• for next meeting (10/2) - everyone have dimensioned sketches of the dribbler and ball control system, specifically for suspension, motor placement, and the chip kicker
  • concept will be chosen for ball control will be chosen on Monday
  • test rig for dribbler bar will be designed and built

Testing

Dribbler test

Functions:

Trap ball

• Ball speed- speed the ball can hit the without moving back. Use a spring and a speed trap to measure the speed.
• Ball angle- rotate the robot
• Rebound- distance the ball bounces back

Hold ball

• Center time- measure time in seconds
• Climb ball- measure change in normal force on the measuring platform
• Pull force- angle of loss of contact. Measure what incline the measuring platform is required for the dribbler to lose contact
• Reverse speed- have the robot on a treadmill and measure when the ball comes lose
• Lateral speed- have the robot on the treadmill but have the dribbler facing tangential to the motion
• Rotational speed- rotate the speed of the carpet and see when the dribbler loses control

Material Test

• Measure either the lifetime of the dribbler under continuous operation and visually inspect the dribbler.

Kicker Test

• Control speed- speed trap measuring velocity versus voltage
• Accuracy- impact test to measure where the ball impacts a wall
• Lifetime- how long does the kicker last both with a ball being hit and when there is no ball. Also measure changes in speed and accuracy over time.
• Frequency- how long between successive firings

Chipper Test

• Range- to where the ball lands
• Angle- accuracy to how close the ball lands
• Lifetime analysis same as kicker

Shell impact Test

• Maximum speed ball at different areas of the shell until it breaks

Omni wheels Test

• Traction- run the robot up an incline

Quick Notes

• field area 5 meters x 3.5 meters
• max ball speed - 10 m/s
• ball diameter - 43 mm
• ball mass - 46 grams
• 1 rpm = .105 rad/s

Useful Links

• Cornell Documents (Look at 2003)

• Eagle Knights Dribbler Testing

• Mechanical Engineering Tips

• G-Code Tutorial

• Overhead camera footage from Robocup 2007 Championship Match