tractor_sim

Package for simulating the Olin Robotics Lab Autonomous Tractor. For further project information, see the GRAVL main repository wiki: (link)

Setup

Dependencies:

GRAVL - for teleop and testing code
Follow setup instructions on the GRAVL wiki if you haven't already (reference)
tractor_sim_packages - packages for simulated localization and odometry
velodyne_simulator - packages for simulated 3D lidar

Installation:

cd ~/catkin_ws/src
git clone https://github.com/olinrobotics/tractor_sim.git
cd ..
rosdep install -iry --from-paths src
cd ~/catkin_ws/
catkin_make

To use the models included in this repo, copy the contents of the folder to ~/.gazebo/models

cd ~/catkin_ws/src/tractor_sim/tractor_sim_gazebo/models
cp -R . ~/.gazebo/models

Usage

To run simulation:

roslaunch tractor_sim_gazebo bringup.launch

ROS Topics

/cmd_vel - twist command for driving the tractor
/cmd_hitch - pose command for setting height of box blade (reference)

Sensor Topics

/camera/image_raw - camera feed
/gps/fix - rtk gps data
/imu/data - imu data
/scan - downward facing LiDar data

Troubleshooting

If using the main launch file doesn't work for you, you can just run individual launch files to suit your needs To run simulation without external dependencies:

roslaunch tractor_sim_gazebo bringup_min.launch

To run rviz:

roslaunch tractor_sim_description tractor_sim_rviz.launch

To test code:

rosrun gravl yourscript.py (ex: rosrun gravl LidarFollower.py)

To run simulation (without teleop, hitch controls, localization, or any extra code running)

roslaunch tractor_sim_gazebo tractor_sim.launch

To run teleop (following https://github.com/olinrobotics/gravl/wiki/Kubo:-Overview):

roslaunch gravl teleop.launch
roslaunch gravl mainstate.launch

To setup localization:

roslaunch gravl localization.launch

To setup hitch commands:

roslaunch tractor_sim_gazebo hitch.launch

Parameters

tractor_delay - either 0 or 1. If set to 1, then tractor will react instantaneously to commands. If set to 1, the tractor will simulate the delayed response time of the real tractor (Default: 1)
max_acceleration - maximum acceleration for the tractor Note: only works when tractor_delay is 0 (Default: 0.4)
max_steering_angle_velocity - maximum steering velocity Note: only works when tractor_delay is set to 0 (Default: 1)

Known Issues

Running the launch file will throw the warning

[WARN] [1590601461.920958, 0.000000]: Controller Spawner couldn't find the expected controller_manager ROS interface.

if the controller spawner loads before gazebo loads, which is likely. To get around this, in the launch file the controller spawner's node has respawn="true". Ideally, this should wait for gazebo to finish loading before starting the node so that the warning doesn't pop up, but this works for now.

ipa-rar / tractor_sim