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External Velocity Limit Selector#

Purpose#

The external_velocity_limit_selector_node is a node that keeps consistency of external velocity limits. This module subscribes

  1. velocity limit command sent by API,
  2. velocity limit command sent by Autoware internal modules.

VelocityLimit.msg contains not only max velocity but also information about the acceleration/jerk constraints on deceleration. The external_velocity_limit_selector_node integrates the lowest velocity limit and the highest jerk constraint to calculate the hardest velocity limit that protects all the deceleration points and max velocities sent by API and Autoware internal modules.

selector algorithm

Inner-workings / Algorithms#

WIP

Inputs#

Name Type Description
~input/velocity_limit_from_api autoware_internal_planning_msgs::msg::VelocityLimit velocity limit from api
~input/velocity_limit_from_internal autoware_internal_planning_msgs::msg::VelocityLimit velocity limit from autoware internal modules
~input/velocity_limit_clear_command_from_internal autoware_internal_planning_msgs::msg::VelocityLimitClearCommand velocity limit clear command

Outputs#

Name Type Description
~output/max_velocity autoware_internal_planning_msgs::msg::VelocityLimit current information of the hardest velocity limit

Parameters#

Name Type Description Default Range
max_velocity float Default max velocity [m/s] 20 N/A
Name Type Description Default Range
----------------- -------- ------------------------------- ----------- ---------
max_vel float max velocity limit [m/s] 11.1 N/A
normal.min_acc float min deceleration [m/ss] -0.5 N/A
normal.max_acc float max acceleration [m/ss] 1 N/A
normal.min_jerk float min jerk [m/sss] -0.5 N/A
normal.max_jerk float max jerk [m/sss] 1 N/A
limit.min_acc float min deceleration limit [m/ss] -2.5 N/A
limit.max_acc float max acceleration [m/ss] 1 N/A
limit.min_jerk float min jerk [m/sss] -1.5 N/A
limit.max_jerk float max jerk [m/sss] 1.5 N/A

Assumptions / Known limits#

(Optional) Error detection and handling#

(Optional) Performance characterization#

(Optional) Future extensions / Unimplemented parts#