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< ChSuspensionTestRigDriver > 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.

ChWheeledVehicle &	GetVehicle () const
	Get a handle to the underlying vehicle system.

const ChVector3d &	GetSpindlePos (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 ChVector3d &	GetSpindleLinVel (int axle, VehicleSide side) const
	Get the linear velocity of the specified spindle (expressed in the global reference frame). More...

ChVector3d	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< ChWheeledVehicle >	m_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

vehicle	test vehicle
axle_index	list of tested vehicle axles
displ_limit	displacement 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()

ChVector3d 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 ChVector3d & 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 ChVector3d & 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

type	type of output DB
out_dir	output directory name
out_name	rootname of output file
output_step	interval 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

Description

Public Member Functions

Protected Member Functions

Protected Attributes

Constructor & Destructor Documentation

◆ ChSuspensionTestRig() [1/2]

◆ ChSuspensionTestRig() [2/2]

Member Function Documentation

◆ CalcDisplacementOffset()

◆ CalcTerrainHeight()

◆ GetRideHeight()

◆ GetSpindleAngVel()

◆ GetSpindleLinVel()

◆ GetSpindlePos()

◆ GetSpindleRot()

◆ GetWheelTravel()

◆ Initialize()

◆ PlotOutput()

◆ SetInitialRideHeight()

◆ SetOutput()

◆ SetPlotOutput()