ROS Nodes
These are the ROS Nodes provided by this package.
Most likely, you will use a launch file to run these. You can also run them
by using rosrun:
rosrun rktl_planner <Node name>
bezier_path_server
This node is a ROS service that creates a Bezier path using a series of input poses, target durations, and segment durations. The output includes the Bezier path (which is a series of connected Bezier curves) and a linear path (which is a series of linear segments that approximate the Bezier path). The Bezier path is designed to allow for smooth turns and gradual acceleration and deceleration, while the linear path is used for easier computation and execution.
Services:
create_bezier_path(rktl_planner/CreateBezierPath): A service that creates a Bezier path using the input poses and durations.
path_follower
This node ensures the car follows a given trajectory using the pure pursuit
algorithm. It subscribes to the /cars/{car_name}/odom topic to obtain the
car’s odometry information and the /linear_path topic to receive the desired
path. It then publishes the control commands to the /cars/{car_name}/command
topic.
Subscribed Topics:
/cars/{car_name}/odom(nav_msgs/Odometry): The car’s odometry information containing its position, orientation, and velocities.linear_path(rktl_msgs/Path): The desired path that the car should follow.
Published Topics:
/cars/{car_name}/command(rktl_msgs/ControlCommand): The control commands to be sent to the car to follow the desired path
Parameters:
~frame_id(str, default: ‘map’): The frame ID for the path and pose messages.~max_speed(float, default: 0.1): The maximum speed at which the car should travel along the path.~lookahead_dist(float, default: 0.15): The distance ahead of the car to look for the next point on the path.~lookahead_gain(float, default: 0.035): The coefficient used to adjust the lookahead distance based on the car’s current speed.~lookahead_pnts(int, default: -1): The number of points to search along the path for the next valid intersection. If set to -1, the entire path is searched.~car_name(str): The name of the car to which this node belongs.
path_planner
This node uses bezier_path_server to generate bezier paths between a car and
the ball in order to hit the ball into a goal. Options exist for generating a
‘simple’ or ‘complex’ path to the ball. A ‘simple’ path is a direct path between
the current position of the car and the ball’s position, while a ‘complex’ path
takes into account the orientation of the car and decides whether to take a
direct path or to generate a path in reverse.
Subscribed Topics:
/cars/{car_name}/odom(nav_msgs/Odometry): The car’s odometry information containing its position, orientation, and velocities.
Published Topics:
linear_path(rktl_msgs/Path): The desired path that the car should follow, split into linear segmentsbezier_path(rktl_msgs/BezierPath): The desired path that the car should follow, split into bezier segments
Services:
reset_planner(std_srvs/Empty): An empty service that is used to trigger the generation/regeneration of the path based on the odemetry of the car and ball. The new path is published on the topics above.
Parameters:
~frame_id(str, default: ‘map’): The frame ID for the path and pose messages.~max_speed(float, default: 0.1): The maximum speed at which the car should travel along the path.~lookahead_dist(float, default: 0.15): The distance ahead of the car to look for the next point on the path.~lookahead_gain(float, default: 0.035): The coefficient used to adjust the lookahead distance based on the car’s current speed.~lookahead_pnts(int, default: -1): The number of points to search along the path for the next valid intersection. If set to -1, the entire path is searched.~car_name(str): The name of the car to which this node belongs.
patrol_planner
This node implements a “patrol”-based algorithm to control the car. The car “patrols” around the field in a circle and makes a beeline towards the ball if it seems like it would result in a goal. Logic is in place for both offensive and defensive modes. A Proportional Derivative (PD) controller is used to determine how much to turn.
Subscribed Topics:
odom(nav_msgs/Odometry): The car’s odometry information, containing its position, orientation, and velocities./ball/odom(nav_msgs/Odometry): The ball’s odometry information, containing its position, orientation, and velocities.
Published Topics:
command(rktl_msgs/ControlCommand): The control commands to be sent to the car to perform the patrol algorithm
Parameters:
/field/width(float): Physical constant, width of the field/field/length(float): Physical constant, length of the field/cars/steering/max_throw(float): Physical constant, maximum steering throw/cars/length(float): Physical constant, car length~speed(float, default: 1.0): Maximum speed of the car~curvature_gain/kp(float, default: 1.0): Parameter for PD Controller~curvature_gain/kd(float, default: 0.0): Parameter for PD Controller~curvature_gain/falloff(float, default: 1e-9): Parameter for PD Controller~patrol_wall_dist(float, default: 0.5)~wall_avoidance/reverse_time(float, default: 0.25)~wall_avoidance/distance_margin(float, default: 0.5)~wall_avoidance/heading_margin(float, default: π/4)~attempt_timeout(float, default: 5.0)~defensive_line(float: 0.0)~reverse_line(float: 0.0)~scoring/heading_margin(float, default: π/8)~scoring/car_lookahead_dist(float, default: 1.0)~scoring/ball_lookahead_time(float, default: 0.0)~scoring/goal_depth_target(float, default: 0.0)~defense/reverse_time_gain(float, default: 0.5)