Drivetrain

Each platform comes with a default drivetrain controller and set of wheels. Some platforms support different controllers, and some support multiple wheel types. The drivetrain section determines which velocity controller to load, and which wheels to define in the robot description.

The following drivetrain controllers are supported:

• diff_4wd: Differential four-wheel drive
• diff_fwd: Differential front-wheel drive
• diff_rwd: Differential rear-wheel drive
• omni_4wd: Omnidirectional four-wheel drive

note

The control type is determined by which wheels are controlled, not how many motors a platform has. An A200 has one motor per side which control two motors each, so it can only be diff_4wd.

The following wheel types are supported:

• outdoor: Rugged outdoor wheels
• indoor: Smooth indoor wheels
• mecanum: Roller wheels for omnidirectional control
• tracks: Continuous track system
• caster: Uncontrolled caster wheels

The drivetrain section defines the keys control and wheels to set these parameters. Under wheel, the front and rear wheels are set separately. Some example configurations are shown below.

diff_4wd

drivetrain:
  control: diff_4wd
  wheels:
    front: outdoor
    rear: outdoor

omni_4wd

drivetrain:
  control: omni_4wd
  wheels:
    front: mecanum
    rear: mecanum

diff_fwd

drivetrain:
  control: diff_fwd
  wheels:
    front: indoor
    rear: caster

diff_rwd

drivetrain:
  control: diff_rwd
  wheels:
    front: caster
    rear: outdoor

note

Not all configurations are valid. For example, an omni_4wd controller must be matched with four mecanum wheels. Also, caster wheels cannot be attached to wheels which are controlled.

Supported controllers and wheels

Platform	Control	Front Wheels	Rear Wheels
A200	[diff_4wd]	[outdoor] indoor	[outdoor] indoor
A300	[diff_4wd] diff_fwd diff_rwd omni_4wd	[outdoor] mecanum caster	[outdoor] mecanum caster
J100	[diff_4wd]	[outdoor]	[outdoor]
W200	[diff_4wd]	[outdoor] tracks	[outdoor] tracks
DD100	[diff_fwd]	[indoor]	[caster]
DO100	[omni_4wd] diff_4wd	[mecanum]	[mecanum]
DD150	[diff_fwd]	[indoor]	[caster]
DO150	[omni_4wd] diff_4wd	[mecanum]	[mecanum]
R100	[omni_4wd] diff_4wd	[mecanum]	[mecanum]

note

Default configurations are noted with square brackets.