Carla Ackermann Control
The carla_ackermann_control package is used to control a CARLA vehicle with Ackermann messages. The package converts the Ackermann messages into CarlaEgoVehicleControl messages. It reads vehicle information from CARLA and passes that information to a Python based PID controller called simple-pid to control the acceleration and velocity.
Configuration
Parameters can be set both initially in a configuration file when using both ROS 1 and ROS 2 and during runtime via ROS dynamic reconfigure in ROS 1.
Testing control messages
Test the setup by sending commands to the car via the topic /carla/<ROLE NAME>/ackermann_cmd. For example, move an ego vehicle with the role name of ego_vehicle forward at a speed of 10 meters/sec by running this command:
# ROS 1
rostopic pub /carla/ego_vehicle/ackermann_cmd ackermann_msgs/AckermannDrive "{steering_angle: 0.0, steering_angle_velocity: 0.0, speed: 10, acceleration: 0.0, jerk: 0.0}" -r 10
# ROS 2
ros2 topic pub /carla/ego_vehicle/ackermann_cmd ackermann_msgs/AckermannDrive "{steering_angle: 0.0, steering_angle_velocity: 0.0, speed: 10, acceleration: 0.0, jerk: 0.0}" -r 10
Or make the vehicle move forward while turning at an angle of 1.22 radians:
# ROS 1
rostopic pub /carla/ego_vehicle/ackermann_cmd ackermann_msgs/AckermannDrive "{steering_angle: 1.22, steering_angle_velocity: 0.0, speed: 10, acceleration: 0.0, jerk: 0.0}" -r 10
# ROS 2
ros2 topic pub /carla/ego_vehicle/ackermann_cmd ackermann_msgs/AckermannDrive "{steering_angle: 1.22, steering_angle_velocity: 0.0, speed: 10, acceleration: 0.0, jerk: 0.0}" -r 10
ROS API
Subscriptions
| Topic | Type | Description |
|---|---|---|
/carla/<ROLE NAME>/ackermann_cmd |
ackermann_msgs.AckermannDrive | Subscriber for steering commands |
Publications
| Topic | Type | Description |
|---|---|---|
/carla/<ROLE NAME>/ackermann_control/control_info |
carla_ackermann_control.EgoVehicleControlInfo | The current values used within the controller (useful for debugging) |