chrono::vehicle::ChPathSteeringController Class Reference

Description

Path-following steering PID controller.

The path to be followed is specified as a ChBezierCurve object and the target point is defined to be the point on that path that is closest to the current location of the sentinel point.

#include <ChSteeringController.h>

Inheritance diagram for chrono::vehicle::ChPathSteeringController:
Collaboration diagram for chrono::vehicle::ChPathSteeringController:

Public Member Functions

 ChPathSteeringController (std::shared_ptr< ChBezierCurve > path, bool isClosedPath=false)
 Construct a steering controller to track the specified path. More...
 
 ChPathSteeringController (const std::string &filename, std::shared_ptr< ChBezierCurve > path, bool isClosedPath=false)
 Construct a steering controller to track the specified path. More...
 
void SetGains (double Kp, double Ki, double Kd)
 Set the gains for the PID controller.
 
virtual void Reset (const ChVehicle &vehicle) override
 Reset the PID controller. More...
 
virtual void CalcTargetLocation () override
 Calculate the current target point location. More...
 
virtual double Advance (const ChVehicle &vehicle, double step) override
 Advance the state of the PID controller. More...
 
- Public Member Functions inherited from chrono::vehicle::ChSteeringController
virtual ~ChSteeringController ()
 Destructor.
 
void SetLookAheadDistance (double dist)
 Specify the look-ahead distance. More...
 
const ChVectorGetSentinelLocation () const
 Return the current location of the sentinel point. More...
 
const ChVectorGetTargetLocation () const
 Return the current value of the target point. More...
 
std::shared_ptr< ChBezierCurveGetPath () 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< ChBezierCurvem_path
 tracked path (piecewise cubic Bezier curve)
 
double m_dist
 look-ahead distance
 
ChVector m_sentinel
 position of sentinel point in global frame
 
ChVector 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::CSV_writer * m_csv
 CSV_writer object for data collection.
 
bool m_collect
 flag indicating whether or not data is being collected
 

Constructor & Destructor Documentation

◆ ChPathSteeringController() [1/2]

chrono::vehicle::ChPathSteeringController::ChPathSteeringController ( std::shared_ptr< ChBezierCurve path,
bool  isClosedPath = false 
)

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.

◆ ChPathSteeringController() [2/2]

chrono::vehicle::ChPathSteeringController::ChPathSteeringController ( const std::string &  filename,
std::shared_ptr< ChBezierCurve path,
bool  isClosedPath = false 
)

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

◆ Advance()

double chrono::vehicle::ChPathSteeringController::Advance ( const ChVehicle vehicle,
double  step 
)
overridevirtual

Advance the state of the PID controller.

This function performs the required integration for the integral component of the PID controller and returns the calculated steering value.

Implements chrono::vehicle::ChSteeringController.

◆ CalcTargetLocation()

void chrono::vehicle::ChPathSteeringController::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::ChPathSteeringController::Reset ( const ChVehicle vehicle)
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