Description

Base class for a suspension test rig.

#include <ChSuspensionTestRig.h>

Inheritance diagram for chrono::vehicle::ChSuspensionTestRig:

Public Member Functions

virtual ~ChSuspensionTestRig ()
 Destructor.
 
void SetDriver (std::shared_ptr< ChDriverSTR > driver)
 Set driver system.
 
void SetInitialRideHeight (double height)
 Set the initial ride height (relative to the chassis reference frame). More...
 
void SetDisplacementLimit (double limit)
 Set the limits for post displacement (same for jounce and rebound).
 
void IncludeSteeringMechanism (int index)
 Include the specified steering mechanism in testing.
 
void IncludeSubchassis (int index)
 Include the specified subchassis in testing.
 
void SetSuspensionVisualizationType (VisualizationType vis)
 Set visualization type for the suspension subsystem (default: PRIMITIVES).
 
void SetSteeringVisualizationType (VisualizationType vis)
 Set visualization type for the steering subsystems (default: PRIMITIVES).
 
void SetSubchassisVisualizationType (VisualizationType vis)
 Set visualization type for the subchassis subsystems (default: PRIMITIVES).
 
void SetWheelVisualizationType (VisualizationType vis)
 Set visualization type for the wheel subsystems (default: NONE).
 
void SetTireVisualizationType (VisualizationType vis)
 Set visualization type for the tire subsystems (default: PRIMITIVES).
 
void Initialize ()
 Initialize the suspension test rig. More...
 
void Advance (double step)
 Advance the state of the suspension test rig by the specified time step.
 
ChWheeledVehicleGetVehicle () const
 Get a handle to the underlying vehicle system.
 
const ChVectorGetSpindlePos (int axle, VehicleSide side) const
 Get the global location of the specified spindle. More...
 
ChQuaternion GetSpindleRot (int axle, VehicleSide side) const
 Get the global rotation of the specified spindle. More...
 
const ChVectorGetSpindleLinVel (int axle, VehicleSide side) const
 Get the linear velocity of the specified spindle (expressed in the global reference frame). More...
 
ChVector GetSpindleAngVel (int axle, VehicleSide side) const
 Get the angular velocity of the specified spindle (expressed in the global reference frame). More...
 
double GetSteeringInput () const
 Return current driver steering input.
 
virtual double GetActuatorDisp (int axle, VehicleSide side)=0
 Return the current post displacement for the specified axle and vehicle side.
 
virtual double GetActuatorForce (int axle, VehicleSide side)=0
 Return the current post actuation force for the specified axle and vehicle side.
 
double GetWheelTravel (int axle, VehicleSide side) const
 Get wheel travel, defined here as the vertical displacement of the spindle center from its position at the initial specified ride height (or initial configuration, if an initial ride height is not specified). More...
 
virtual double GetRideHeight (int axle) const =0
 Get current ride height for the specified axle (relative to the chassis reference frame). More...
 
std::string GetDriverMessage () const
 Return the info message from the STR driver.
 
bool DriverEnded () const
 Return true when driver stopped producing inputs.
 
void LogConstraintViolations ()
 Log current constraint violations.
 
void SetOutput (ChVehicleOutput::Type type, const std::string &out_dir, const std::string &out_name, double output_step)
 Enable output for this vehicle system (default: false). More...
 
void SetPlotOutput (double output_step)
 Enable data collection for plot generation (default: false). More...
 
void PlotOutput (const std::string &out_dir, const std::string &out_name)
 Plot collected data. More...
 

Protected Member Functions

 ChSuspensionTestRig (std::shared_ptr< ChWheeledVehicle > vehicle, std::vector< int > axle_index, double displ_limit)
 Construct a test rig for specified sets of axles and sterring mechanisms of a given vehicle. More...
 
 ChSuspensionTestRig (const std::string &spec_filename)
 Construct a test rig from the given JSON specification file. More...
 
virtual void InitializeRig ()=0
 Create and initialize the bodies, joints, and actuators of the rig mechanism.
 
virtual double CalcDisplacementOffset (int axle)=0
 Calculate required actuator displacement offset to impose specified ride height. More...
 
virtual double CalcTerrainHeight (int axle, VehicleSide side)=0
 Calculate current terrain height under the specified post. More...
 
virtual void UpdateActuators (std::vector< double > displ_left, std::vector< double > displ_speed_left, std::vector< double > displ_right, std::vector< double > displ_speed_right)=0
 Update actuators at current time.
 
void CollectPlotData (double time)
 Collect data for plot output.
 

Protected Attributes

std::shared_ptr< ChWheeledVehiclem_vehicle
 associated vehicle
 
int m_naxles
 number of tested axles
 
std::vector< int > m_axle_index
 list of tested vehicle axles in rig
 
std::vector< int > m_steering_index
 list of tested vehicle steering mechanisms in rig
 
std::vector< int > m_subchassis_index
 list of tested vehicle subchassis mechanisms in rig
 
double m_ride_height
 ride height
 
double m_displ_limit
 scale factor for post displacement
 
std::vector< double > m_displ_offset
 post displacement offsets (to set reference positions)
 

Constructor & Destructor Documentation

◆ ChSuspensionTestRig() [1/2]

chrono::vehicle::ChSuspensionTestRig::ChSuspensionTestRig ( std::shared_ptr< ChWheeledVehicle vehicle,
std::vector< int >  axle_index,
double  displ_limit 
)
protected

Construct a test rig for specified sets of axles and sterring mechanisms of a given vehicle.

Parameters
vehicletest vehicle
axle_indexlist of tested vehicle axles
displ_limitdisplacement limits

◆ ChSuspensionTestRig() [2/2]

chrono::vehicle::ChSuspensionTestRig::ChSuspensionTestRig ( const std::string &  spec_filename)
protected

Construct a test rig from the given JSON specification file.

An STR specification file includes the JSON specification for the underlying vehicle, the sets of tested vehicle subsystems, and the displacement limit for the rig posts.

Member Function Documentation

◆ CalcDisplacementOffset()

virtual double chrono::vehicle::ChSuspensionTestRig::CalcDisplacementOffset ( int  axle)
protectedpure virtual

Calculate required actuator displacement offset to impose specified ride height.

Note: 'axle' is the index in the set of tested axles.

◆ CalcTerrainHeight()

virtual double chrono::vehicle::ChSuspensionTestRig::CalcTerrainHeight ( int  axle,
VehicleSide  side 
)
protectedpure virtual

Calculate current terrain height under the specified post.

Note: 'axle' is the index in the set of tested axles.

◆ GetRideHeight()

virtual double chrono::vehicle::ChSuspensionTestRig::GetRideHeight ( int  axle) const
pure virtual

Get current ride height for the specified axle (relative to the chassis reference frame).

This estimate uses the average of the left and right posts. Note: 'axle' is the index in the set of tested axles.

Implemented in chrono::vehicle::ChSuspensionTestRigPushrod, and chrono::vehicle::ChSuspensionTestRigPlatform.

◆ GetSpindleAngVel()

ChVector chrono::vehicle::ChSuspensionTestRig::GetSpindleAngVel ( int  axle,
VehicleSide  side 
) const

Get the angular velocity of the specified spindle (expressed in the global reference frame).

Note: 'axle' is the index in the set of tested axles.

◆ GetSpindleLinVel()

const ChVector & chrono::vehicle::ChSuspensionTestRig::GetSpindleLinVel ( int  axle,
VehicleSide  side 
) const

Get the linear velocity of the specified spindle (expressed in the global reference frame).

Note: 'axle' is the index in the set of tested axles.

◆ GetSpindlePos()

const ChVector & chrono::vehicle::ChSuspensionTestRig::GetSpindlePos ( int  axle,
VehicleSide  side 
) const

Get the global location of the specified spindle.

Note: 'axle' is the index in the set of tested axles.

◆ GetSpindleRot()

ChQuaternion chrono::vehicle::ChSuspensionTestRig::GetSpindleRot ( int  axle,
VehicleSide  side 
) const

Get the global rotation of the specified spindle.

Note: 'axle' is the index in the set of tested axles.

◆ GetWheelTravel()

double chrono::vehicle::ChSuspensionTestRig::GetWheelTravel ( int  axle,
VehicleSide  side 
) const

Get wheel travel, defined here as the vertical displacement of the spindle center from its position at the initial specified ride height (or initial configuration, if an initial ride height is not specified).

Note: 'axle' is the index in the set of tested axles.

◆ Initialize()

void chrono::vehicle::ChSuspensionTestRig::Initialize ( )

Initialize the suspension test rig.

Initialize and prepare the associated vehicle and rig driver, then let derived classes construct the bodies, joints, and actuators of the rig mechanism.

◆ PlotOutput()

void chrono::vehicle::ChSuspensionTestRig::PlotOutput ( const std::string &  out_dir,
const std::string &  out_name 
)

Plot collected data.

When called (typically at the end of the simulation loop), the collected data is saved in ASCII format in a file with the specified name (and 'txt' extension) in the specified output directory. If the Chrono::Postprocess module is available (with gnuplot support), selected plots are generated.

◆ SetInitialRideHeight()

void chrono::vehicle::ChSuspensionTestRig::SetInitialRideHeight ( double  height)
inline

Set the initial ride height (relative to the chassis reference frame).

If not specified, the reference height is the suspension design configuration.

◆ SetOutput()

void chrono::vehicle::ChSuspensionTestRig::SetOutput ( ChVehicleOutput::Type  type,
const std::string &  out_dir,
const std::string &  out_name,
double  output_step 
)

Enable output for this vehicle system (default: false).

Parameters
typetype of output DB
out_diroutput directory name
out_namerootname of output file
output_stepinterval between output times

◆ SetPlotOutput()

void chrono::vehicle::ChSuspensionTestRig::SetPlotOutput ( double  output_step)

Enable data collection for plot generation (default: false).

Collected data includes:

  • [col 1] time (s)
  • [col 2-5] left input, left spindle z (m), left spindle z velocity (m/s), left wheel travel (m)
  • [col 6-7] left spring force (N), left shock force (N)
  • [col 8-11] right input, right spindle z (m), right spindle z velocity (m/s), right wheel travel (m)
  • [col 12-13] right spring force (N), right shock force (N)
  • [col 14] estimated ride height (m)
  • [col 15] left camber angle, gamma (deg)
  • [col 16] right camber angle, gamma (deg)
  • [col 17-19] application point for left tire force (m)
  • [col 20-22] left tire force (N)
  • [col 23-25] left tire moment (Nm)
  • [col 26-28] application point for right tire force (m)
  • [col 29-31] right tire force (N)
  • [col 32-34] right tire moment (Nm) Tire forces are expressed in the global frame, as applied to the center of the associated wheel.

The documentation for this class was generated from the following files:
  • /builds/uwsbel/chrono/src/chrono_vehicle/wheeled_vehicle/test_rig/ChSuspensionTestRig.h
  • /builds/uwsbel/chrono/src/chrono_vehicle/wheeled_vehicle/test_rig/ChSuspensionTestRig.cpp