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.
The parameters of a steering controller can also be specified through a JSON file; sample JSON input file:
{
"Gains":
{
"Kp": 0.5,
"Ki" : 0.0,
"Kd" : 0.0
}, "Lookahead Distance": 20.0
}
#include <ChSteeringController.h>
Public Member Functions | |
| ChPathSteeringController (std::shared_ptr< ChBezierCurve > path) | |
| Construct a steering controller to track the specified path. More... | |
| ChPathSteeringController (const std::string &filename, std::shared_ptr< ChBezierCurve > path) | |
| 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 ChFrameMoving<> &ref_frame) override |
| Reset the PID controller. More... | |
| virtual void | CalcTargetLocation () override |
| Calculate the current target point location. More... | |
| virtual double | Advance (const ChFrameMoving<> &ref_frame, double time, 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 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
◆ ChPathSteeringController() [1/2]
| chrono::vehicle::ChPathSteeringController::ChPathSteeringController | ( | std::shared_ptr< ChBezierCurve > | path | ) |
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 | ||
| ) |
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()
|
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()
|
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()
|
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
