Drive Bases

Holonomic: Can translate and rotate in all directions simultaneously, not just forwards and rotating.

Omni Wheel: A wheel with smaller wheels mounted around its circumference allowing to to provide power in one direction but slide passively in the other.

Swerve Drive

  • Each wheel can rotate independently, letting the robot rotate and translate as requested

  • Very maneuverable

  • Expensive, Complex

  • Uses 8 of the 16 power distribution slots

  • Certified coolest drive base (certifiable)

The team used to make our own swerve drive modules (2018-2020) but have now bought SDS MK4i's and we will likely use them for the foreseeable future unless the game makes them unsuitable (e.g. requires driving over obstacles)


Tank Drive

Also called differential drive, west coast drive and skid steer.

  • 2-3 Wheels on each side which are either slaved together or driven individually

  • Easy to build, Cheap

  • High Grip, Good straight line speed

  • Turning can be difficult and slow

    • Usually either a dropped center wheel and/or omni wheels in the corners to make turning easier.

We have used tank drive in the past and may consider it again for its ease, robustness.

The following we will likely not use on a competition robot but are still interesting.

H-drive

  • Omni wheels in four corners in tank drive configuration, however with one “drop wheel” in the middle to move sideways

  • Also possible to have two wheels in the center at the top and bottom for more powerful and faster strafing

  • Low grip

  • Preferences one directly making field relative controls harder.

Omni Drive

  • Three (if robot is triangular) or four (if robot is square) omni wheels in the corners of the robot

  • Driving them at different relative speeds lets the robot move in any direction, and rotate however it wants.

  • Simple mechanics

  • Immediate turning

  • Minimal pushing power

Mecanum Drive

  • Four Mecanum wheels

  • Fully holonomic.

  • Lower grip.

  • May exhibit unusual characteristics when turning depending on the weight distribution.

Very popular in other robotics competitions (FTC, VEX)

Grasshopper

  • Actuated wheels that swap between tank and either H-drive or Mecanum drive.

  • Heavy and complex