SimpleController Class Reference

A simple path-following controller using PID and look-ahead strategy. More...

#include <SimpleController.hpp>

Inheritance diagram for SimpleController:

Collaboration diagram for SimpleController:

Public Member Functions
std::expected< void, std::string >	on_initialize () override
	Initializes parameters and PID controllers.
	SimpleController ()
void	update_rt (NavState &nav_state) override
	Updates the controller using the given NavState.
	~SimpleController () override
	Destructor.

Protected Member Functions
double	get_angle (const geometry_msgs::msg::Point &from, const geometry_msgs::msg::Point &to)
	Computes the angle between two points.
double	get_diff_angle (const geometry_msgs::msg::Quaternion &a, const geometry_msgs::msg::Quaternion &b)
	Computes the angular difference between two quaternions (yaw).
double	get_distance (const geometry_msgs::msg::Pose &a, const geometry_msgs::msg::Pose &b)
	Computes the Euclidean distance between two poses.
geometry_msgs::msg::Pose	get_ref_pose (const nav_msgs::msg::Path &path, double look_ahead)
	Gets the reference pose at look-ahead distance on the path.

Protected Attributes
std::shared_ptr< PIDController >	angular_pid_
	PID controller for angular velocity.
double	k_rot_ {0.5}
rclcpp::Time	last_update_ts_
	Timestamp of the last control update.
double	last_vlin_ {0.0}
	Previous linear velocity for acceleration limiting.
double	last_vrot_ {0.0}
	Previous angular velocity for acceleration limiting.
std::shared_ptr< PIDController >	linear_pid_
	PID controller for linear velocity.
double	look_ahead_dist_ {1.0}
	Distance ahead of the robot to track in meters.
double	max_angular_acc_ {0.3}
	Maximum angular acceleration in rad/s².
double	max_angular_speed_ {1.0}
	Maximum angular speed in rad/s.
double	max_linear_acc_ {0.3}
	Maximum linear acceleration in m/s².
double	max_linear_speed_ {1.0}
	Maximum linear speed in m/s.
double	tolerance_dist_ {0.05}
	Distance threshold to switch to orientation tracking.
geometry_msgs::msg::TwistStamped	twist_stamped_
	Current velocity command.

Detailed Description

A simple path-following controller using PID and look-ahead strategy.

Constructor & Destructor Documentation

SimpleController()

SimpleController

(

)

~SimpleController()

~SimpleController ( )

overridedefault

Destructor.

Member Function Documentation

get_angle()

double get_angle ( const geometry_msgs::msg::Point & from, const geometry_msgs::msg::Point & to )

protected

Computes the angle between two points.

Parameters

from	Start point.
to	End point.

Returns

Angle in radians.

get_diff_angle()

double get_diff_angle ( const geometry_msgs::msg::Quaternion & a, const geometry_msgs::msg::Quaternion & b )

protected

Computes the angular difference between two quaternions (yaw).

Parameters

a	First quaternion.
b	Second quaternion.

Returns

Angle difference in radians within [-π, π].

get_distance()

double get_distance ( const geometry_msgs::msg::Pose & a, const geometry_msgs::msg::Pose & b )

protected

Computes the Euclidean distance between two poses.

Parameters

a	First pose.
b	Second pose.

Returns

Distance in meters.

get_ref_pose()

geometry_msgs::msg::Pose get_ref_pose ( const nav_msgs::msg::Path & path, double look_ahead )

protected

Gets the reference pose at look-ahead distance on the path.

Parameters

path	The planned path.
look_ahead	Distance to look ahead in meters.

Returns

PoseStamped representing the goal reference.

on_initialize()

std::expected< void, std::string > on_initialize ( )

override

Initializes parameters and PID controllers.

Returns

std::expected<void, std::string> success or error message.

update_rt()

void update_rt ( NavState & nav_state )

override

Updates the controller using the given NavState.

Parameters

nav_state

Current navigation state, including odometry and planned path.

Member Data Documentation

angular_pid_

std::shared_ptr<PIDController> angular_pid_

protected

PID controller for angular velocity.

k_rot_

double k_rot_ {0.5}

protected

last_update_ts_

rclcpp::Time last_update_ts_

protected

Timestamp of the last control update.

last_vlin_

double last_vlin_ {0.0}

protected

Previous linear velocity for acceleration limiting.

last_vrot_

double last_vrot_ {0.0}

protected

Previous angular velocity for acceleration limiting.

linear_pid_

std::shared_ptr<PIDController> linear_pid_

protected

PID controller for linear velocity.

look_ahead_dist_

double look_ahead_dist_ {1.0}

protected

Distance ahead of the robot to track in meters.

max_angular_acc_

double max_angular_acc_ {0.3}

protected

Maximum angular acceleration in rad/s².

max_angular_speed_

double max_angular_speed_ {1.0}

protected

Maximum angular speed in rad/s.

max_linear_acc_

double max_linear_acc_ {0.3}

protected

Maximum linear acceleration in m/s².

max_linear_speed_

double max_linear_speed_ {1.0}

protected

Maximum linear speed in m/s.

tolerance_dist_

double tolerance_dist_ {0.05}

protected

Distance threshold to switch to orientation tracking.

twist_stamped_

geometry_msgs::msg::TwistStamped twist_stamped_

protected

Current velocity command.

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The documentation for this class was generated from the following files:

• easynav_simple_controller/include/easynav_simple_controller/SimpleController.hpp
• easynav_simple_controller/src/easynav_simple_controller/SimpleController.cpp