Description

"Pure Pursuit" path-following controller This implementation is based on the CARLA Pure Pursuit controller: https://carla.org// https://thomasfermi.github.io/Algorithms-for-Automated-Driving/Control/PurePursuit.html Original algorithm documented at: https://www.ri.cmu.edu/pub_files/pub3/coulter_r_craig_1992_1/coulter_r_craig_1992_1.pdf

#include <ChSteeringController.h>

Inheritance diagram for chrono::vehicle::ChPathSteeringControllerPP:

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Collaboration diagram for chrono::vehicle::ChPathSteeringControllerPP:

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Public Member Functions
	ChPathSteeringControllerPP (std::shared_ptr< ChBezierCurve > path, double max_wheel_turn_angle=0.0, double wheel_base=2.0)
	Construct a steering controller to track the specified path. More...

	ChPathSteeringControllerPP (const std::string &filename, std::shared_ptr< ChBezierCurve > path, double max_wheel_turn_angle=0.0, double wheel_base=2.0)
	Construct a steering controller to track the specified path. More...

void	SetGain (double Kd)
	Set the gain for the PP controller.

void	SetPreviewDistance (double pvd)

void	SetStartSpeed (double v_start)

virtual double	Advance (const ChFrameMoving<> &ref_frame, double time, double step) override
	Advance the state of the Stanley controller.

virtual void	Reset (const ChFrameMoving<> &ref_frame) override
	Reset the PID controller. More...

virtual void	CalcTargetLocation () override
	Calculate the current target point location. More...

double	CalcHeadingError (ChVector3d &a, ChVector3d &b)

Public Member Functions inherited from chrono::vehicle::ChSteeringController
virtual	~ChSteeringController ()
	Destructor.

void	SetLookAheadDistance (double dist)
	Specify the look-ahead distance. More...

const ChVector3d &	GetSentinelLocation () const
	Return the current location of the sentinel point. More...

const ChVector3d &	GetTargetLocation () const
	Return the current value of the target point. More...

std::shared_ptr< ChBezierCurve >	GetPath () const
	Return a pointer to the Bezier curve.

void	StartDataCollection ()
	Start/restart data collection.

void	StopDataCollection ()
	Suspend/stop data collection.

bool	IsDataCollectionEnabled () const
	Return true if data is being collected.

bool	IsDataAvailable () const
	Return true if data is available for output.

void	WriteOutputFile (const std::string &filename)
	Output data collected so far to the specified file.

Additional Inherited Members
Protected Member Functions inherited from chrono::vehicle::ChSteeringController
	ChSteeringController (std::shared_ptr< ChBezierCurve > path)
	Construct a steering controller with default parameters.

Protected Attributes inherited from chrono::vehicle::ChSteeringController
std::shared_ptr< ChBezierCurve >	m_path
	tracked path (piecewise cubic Bezier curve)

double	m_dist
	look-ahead distance

ChVector3d	m_sentinel
	position of sentinel point in global frame

ChVector3d	m_target
	position of target point in global frame

double	m_err
	current error (signed distance to target point)

double	m_errd
	error derivative

double	m_erri
	integral of error

utils::ChWriterCSV *	m_csv
	ChWriterCSV object for data collection.

bool	m_collect
	flag indicating whether or not data is being collected

Constructor & Destructor Documentation

◆ ChPathSteeringControllerPP() [1/2]

chrono::vehicle::ChPathSteeringControllerPP::ChPathSteeringControllerPP	(	std::shared_ptr< ChBezierCurve >	path,
		double	max_wheel_turn_angle = `0.0`,
		double	wheel_base = `2.0`
	)

Construct a steering controller to track the specified path.

This version uses default controller parameters (zero gains). The user is responsible for calling SetGains and SetLookAheadDistance.

◆ ChPathSteeringControllerPP() [2/2]

chrono::vehicle::ChPathSteeringControllerPP::ChPathSteeringControllerPP	(	const std::string &	filename,
		std::shared_ptr< ChBezierCurve >	path,
		double	max_wheel_turn_angle = `0.0`,
		double	wheel_base = `2.0`
	)

Construct a steering controller to track the specified path.

This version reads controller gains and lookahead distance from the specified JSON file.

Member Function Documentation

◆ CalcTargetLocation()

void chrono::vehicle::ChPathSteeringControllerPP::CalcTargetLocation ( )

overridevirtual

Calculate the current target point location.

The target point is the point on the associated path that is closest to the current location of the sentinel point.

Implements chrono::vehicle::ChSteeringController.

◆ Reset()

void chrono::vehicle::ChPathSteeringControllerPP::Reset ( const ChFrameMoving<> & ref_frame )

overridevirtual

Reset the PID controller.

This function resets the underlying path tracker using the current location of the sentinel point.

Reimplemented from chrono::vehicle::ChSteeringController.

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

/builds/uwsbel/chrono/src/chrono_vehicle/utils/ChSteeringController.h
/builds/uwsbel/chrono/src/chrono_vehicle/utils/ChSteeringController.cpp