Lateral Controller

Overview

For following target trajectory, control stack needs to output lateral control commands (steering angle, steering angle velocity), and longitudinal control commands (acceleration, velocity). Lateral controller module is responsible for calculation of lateral control commands.

Role

Lateral controller module calculates suitable velocity and acceleration for following target trajectory.

Input

The input to Lateral Controller module:

Input	Data Type	Explanation
Trajectory	autoware_planning_msgs::Trajectory	Target trajectory to follow (target position, orientation, twist, acceleration)
Pose	/tf (tf2_msgs::TFMessage)	Current pose of the vehicle
Twist	geometry_msgs::TwistStamped	Current twist of the vehicle
Steer	autoware_vehicle_msgs::Steering	Current steer of the vehicle

Output

The output type from Lateral Controller module is autoware_control_msgs/ControlCommandStamped.

The main outputs included in autoware_control_msgs/ControlCommandStamped are as follows:

Output	Data Type
Velocity	std_msgs/Float64
Acceleration	std_msgs/Float64
Steering angle	std_msgs/Float64
Steering angle velocity	std_msgs/Float64

Note that velocity and acceleration are always output as 0 from Lateral Controller module.