ArduPilot
Gazebo: add OmniRover with Mecanum wheels
Add two omni rover frames using Mecanum wheels: a 4 wheel rover with frame type OmniX (FRAME_TYPE = 3), and a 3 wheel rover that uses a new frame type Omni3Mecanum.
Figure: 4 wheel rover using frame type OmniX.
Figure: 3 wheel rover using frame type Omni3Mecanum.
Alternatives considered
The Gazebo model repo contains a Mecanum Lift. This model includes a planar controller plugin to move the model about in response to a planar twist command. The approach here is different in that the Mecaum wheels are modelled directly using 9 spheroid rollers in each wheel. There are models for left and right wheels that may be imported into another model using the SDF <include> element. This permits different geometries to be assembled, and allows the ArduPilot plugin to control each wheel directly by assigning it to a PWM channel.
Figure: Mecanum wheel detail displaying roller joints.
Related issues and discussion
- https://discuss.ardupilot.org/t/support-for-omni-boats-coming-in-rover-3-5/31663/1
- https://github.com/ArduPilot/ardupilot/issues/9352
- https://github.com/ArduPilot/ardupilot/issues/11782
- https://github.com/ArduPilot/ardupilot/pull/25204
- https://github.com/ArduPilot/ardupilot/pull/27551
Usage
Run Gazebo
gz sim -v4 -s -r omnirover_playpen.sdf
Run SITL
sim_vehicle.py -v Rover --model JSON --add-param-file=$HOME/SITL_Models/Gazebo/config/omni4rover.param --console --map
Once armed, set the mode to MANUAL and control as follows:
| Channel | Low | High |
|---|---|---|
rc 1 |
yaw left | yaw right |
rc 2 |
not assigned | |
rc 3 |
move back | move forward |
rc 4 |
move left | move right |
Figure: omni rover moving laterally
