Description

Base class for a Pitman Arm steering subsystem.

The steering subsystem is modeled with respect to a right-handed frame with with X pointing towards the front, Y to the left, and Z up (ISO standard).

When attached to a chassis, both an offset and a rotation (as a quaternion) are provided.

#include <ChPitmanArm.h>

Inheritance diagram for chrono::vehicle::ChPitmanArm:
Collaboration diagram for chrono::vehicle::ChPitmanArm:

Public Member Functions

virtual std::string GetTemplateName () const override
 Get the name of the vehicle subsystem template.
 
virtual void Initialize (std::shared_ptr< ChChassis > chassis, const ChVector3d &location, const ChQuaternion<> &rotation) override
 Initialize this steering subsystem. More...
 
virtual void AddVisualizationAssets (VisualizationType vis) override
 Add visualization assets for the steering subsystem. More...
 
virtual void RemoveVisualizationAssets () override
 Remove visualization assets for the steering subsystem.
 
virtual void Synchronize (double time, const DriverInputs &driver_inputs) override
 Update the state of this steering subsystem at the current time. More...
 
virtual void LogConstraintViolations () override
 Log current constraint violations.
 
- Public Member Functions inherited from chrono::vehicle::ChSteering
const ChFrameGetRelTransform () const
 Get the frame of the steering subsystem relative to the associated chassis reference frame.
 
std::shared_ptr< ChBodyGetSteeringLink () const
 Get a handle to the main link of the steering subsystems. More...
 
- Public Member Functions inherited from chrono::vehicle::ChPart
const std::string & GetName () const
 Get the name identifier for this subsystem.
 
void SetName (const std::string &name)
 Set the name identifier for this subsystem.
 
bool IsInitialized () const
 Return flag indicating whether or not the part is fully constructed.
 
double GetMass () const
 Get the subsystem mass. More...
 
const ChFrameGetCOMFrame () const
 Get the current subsystem COM frame (relative to and expressed in the subsystem's reference frame). More...
 
const ChMatrix33GetInertia () const
 Get the current subsystem inertia (relative to the subsystem COM frame). More...
 
const ChFrameGetTransform () const
 Get the current subsystem position relative to the global frame. More...
 
void SetVisualizationType (VisualizationType vis)
 Set the visualization mode for this subsystem.
 
virtual void SetOutput (bool state)
 Enable/disable output for this subsystem.
 
bool OutputEnabled () const
 Return the output state for this subsystem.
 

Protected Types

enum  PointId {
  STEERINGLINK, PITMANARM, REV, UNIV,
  REVSPH_R, REVSPH_S, TIEROD_PA, TIEROD_IA,
  NUM_POINTS
}
 Identifiers for the various hardpoints. More...
 
enum  DirectionId {
  REV_AXIS, UNIV_AXIS_ARM, UNIV_AXIS_LINK, REVSPH_AXIS,
  NUM_DIRS
}
 Identifiers for the various direction unit vectors. More...
 

Protected Member Functions

 ChPitmanArm (const std::string &name, bool vehicle_frame_inertia=false)
 Protected constructor. More...
 
void SetVehicleFrameInertiaFlag (bool val)
 Indicate whether or not inertia matrices are specified with respect to a vehicle-aligned centroidal frame (flag=true) or with respect to the body centroidal frame (flag=false). More...
 
virtual void InitializeInertiaProperties () override
 Initialize subsystem inertia properties. More...
 
virtual void UpdateInertiaProperties () override
 Update subsystem inertia properties. More...
 
virtual const ChVector3d getLocation (PointId which)=0
 Return the location of the specified hardpoint. More...
 
virtual const ChVector3d getDirection (DirectionId which)=0
 Return the unit vector for the specified direction. More...
 
virtual double getSteeringLinkMass () const =0
 Return the mass of the steering link body.
 
virtual double getPitmanArmMass () const =0
 Return the mass of the Pitman arm body.
 
virtual const ChVector3dgetSteeringLinkInertiaMoments () const =0
 Return the moments of inertia of the steering link body.
 
virtual const ChVector3dgetSteeringLinkInertiaProducts () const =0
 Return the products of inertia of the steering link body.
 
virtual const ChVector3dgetPitmanArmInertiaMoments () const =0
 Return the moments of inertia of the Pitman arm body.
 
virtual const ChVector3dgetPitmanArmInertiaProducts () const =0
 Return the products of inertia of the Pitman arm body.
 
virtual double getSteeringLinkRadius () const =0
 Return the radius of the steering link body (visualization only).
 
virtual double getPitmanArmRadius () const =0
 Return the radius of the Pitman arm body (visualization only).
 
virtual double getMaxAngle () const =0
 Return the maximum rotation angle of the revolute joint.
 
- Protected Member Functions inherited from chrono::vehicle::ChSteering
 ChSteering (const std::string &name)
 Construct a steering subsystem with given name.
 
- Protected Member Functions inherited from chrono::vehicle::ChPart
 ChPart (const std::string &name)
 Construct a vehicle subsystem with the specified name.
 
void AddMass (double &mass)
 Add this subsystem's mass. More...
 
void AddInertiaProperties (ChVector3d &com, ChMatrix33<> &inertia)
 Add this subsystem's inertia properties. More...
 
virtual void Create (const rapidjson::Document &d)
 Create a vehicle subsystem from JSON data. More...
 
void ExportBodyList (rapidjson::Document &jsonDocument, std::vector< std::shared_ptr< ChBody >> bodies) const
 Export the list of bodies to the specified JSON document.
 
void ExportShaftList (rapidjson::Document &jsonDocument, std::vector< std::shared_ptr< ChShaft >> shafts) const
 Export the list of shafts to the specified JSON document.
 
void ExportJointList (rapidjson::Document &jsonDocument, std::vector< std::shared_ptr< ChLink >> joints) const
 Export the list of joints to the specified JSON document.
 
void ExportCouplesList (rapidjson::Document &jsonDocument, std::vector< std::shared_ptr< ChShaftsCouple >> couples) const
 Export the list of shaft couples to the specified JSON document.
 
void ExportMarkerList (rapidjson::Document &jsonDocument, std::vector< std::shared_ptr< ChMarker >> markers) const
 Export the list of markers to the specified JSON document.
 
void ExportLinSpringList (rapidjson::Document &jsonDocument, std::vector< std::shared_ptr< ChLinkTSDA >> springs) const
 Export the list of translational springs to the specified JSON document.
 
void ExportRotSpringList (rapidjson::Document &jsonDocument, std::vector< std::shared_ptr< ChLinkRSDA >> springs) const
 Export the list of rotational springs to the specified JSON document.
 
void ExportBodyLoadList (rapidjson::Document &jsonDocument, std::vector< std::shared_ptr< ChLoadBodyBody >> loads) const
 Export the list of body-body loads to the specified JSON document.
 

Protected Attributes

std::shared_ptr< ChBodym_arm
 handle to the Pitman arm body
 
std::shared_ptr< ChLinkMotorRotationAnglem_revolute
 handle to the chassis-arm revolute joint
 
std::shared_ptr< ChLinkRevoluteSphericalm_revsph
 handle to the revolute-spherical joint (idler arm)
 
std::shared_ptr< ChLinkUniversalm_universal
 handle to the arm-link universal joint
 
- Protected Attributes inherited from chrono::vehicle::ChSteering
ChFrame m_rel_xform
 location and orientation relative to associated chassis
 
std::shared_ptr< ChBodym_link
 handle to the main steering link
 
- Protected Attributes inherited from chrono::vehicle::ChPart
std::string m_name
 subsystem name
 
bool m_initialized
 specifies whether ot not the part is fully constructed
 
bool m_output
 specifies whether or not output is generated for this subsystem
 
std::shared_ptr< ChPartm_parent
 parent subsystem (empty if parent is vehicle)
 
double m_mass
 subsystem mass
 
ChMatrix33 m_inertia
 inertia tensor (relative to subsystem COM)
 
ChFrame m_com
 COM frame (relative to subsystem reference frame)
 
ChFrame m_xform
 subsystem frame expressed in the global frame
 

Additional Inherited Members

- Static Public Member Functions inherited from chrono::vehicle::ChPart
static ChMatrix33 TransformInertiaMatrix (const ChVector3d &moments, const ChVector3d &products, const ChMatrix33<> &vehicle_rot, const ChMatrix33<> &body_rot)
 Utility function for transforming inertia tensors between centroidal frames. More...
 
- Static Protected Member Functions inherited from chrono::vehicle::ChPart
static void RemoveVisualizationAssets (std::shared_ptr< ChPhysicsItem > item)
 Erase all visual shapes from the visual model associated with the specified physics item (if any).
 
static void RemoveVisualizationAsset (std::shared_ptr< ChPhysicsItem > item, std::shared_ptr< ChVisualShape > shape)
 Erase the given shape from the visual model associated with the specified physics item (if any).
 

Member Enumeration Documentation

◆ DirectionId

Identifiers for the various direction unit vectors.

Enumerator
REV_AXIS 

revolute joint

UNIV_AXIS_ARM 

universal joint (Pitman arm side)

UNIV_AXIS_LINK 

universal joint (steering link side)

REVSPH_AXIS 

revolute joint for idler arm

◆ PointId

Identifiers for the various hardpoints.

Enumerator
STEERINGLINK 

steering link location (com)

PITMANARM 

Pitman arm location (com)

REV 

location of joint between Pitman arm and chassis

UNIV 

location of joint between Pitman arm and steering link

REVSPH_R 

location of revolute joint for the idler arm

REVSPH_S 

location of spherical joint for the idler arm

TIEROD_PA 

tierod connection point (Pitman arm side)

TIEROD_IA 

tierod connection point (idler arm side)

Constructor & Destructor Documentation

◆ ChPitmanArm()

chrono::vehicle::ChPitmanArm::ChPitmanArm ( const std::string &  name,
bool  vehicle_frame_inertia = false 
)
protected

Protected constructor.

Parameters
[in]namename of the subsystem
[in]vehicle_frame_inertiainertia specified in vehicle-aligned centroidal frames?

Member Function Documentation

◆ AddVisualizationAssets()

void chrono::vehicle::ChPitmanArm::AddVisualizationAssets ( VisualizationType  vis)
overridevirtual

Add visualization assets for the steering subsystem.

This default implementation uses primitives.

Reimplemented from chrono::vehicle::ChPart.

◆ getDirection()

virtual const ChVector3d chrono::vehicle::ChPitmanArm::getDirection ( DirectionId  which)
protectedpure virtual

Return the unit vector for the specified direction.

The returned vector must be expressed in the suspension reference frame.

Implemented in chrono::vehicle::artcar::ARTcar_PitmanArm, chrono::vehicle::PitmanArm, chrono::vehicle::feda::FEDA_PitmanArm, chrono::vehicle::generic::Generic_PitmanArm, chrono::vehicle::hmmwv::HMMWV_PitmanArm, and chrono::vehicle::mrole::mrole_PitmanArm.

◆ getLocation()

virtual const ChVector3d chrono::vehicle::ChPitmanArm::getLocation ( PointId  which)
protectedpure virtual

Return the location of the specified hardpoint.

The returned location must be expressed in the suspension reference frame.

Implemented in chrono::vehicle::artcar::ARTcar_PitmanArm, chrono::vehicle::PitmanArm, chrono::vehicle::feda::FEDA_PitmanArm, chrono::vehicle::generic::Generic_PitmanArm, chrono::vehicle::hmmwv::HMMWV_PitmanArm, and chrono::vehicle::mrole::mrole_PitmanArm.

◆ Initialize()

void chrono::vehicle::ChPitmanArm::Initialize ( std::shared_ptr< ChChassis chassis,
const ChVector3d location,
const ChQuaternion<> &  rotation 
)
overridevirtual

Initialize this steering subsystem.

The steering subsystem is initialized by attaching it to the specified chassis at the specified location (with respect to and expressed in the reference frame of the chassis) and with specified orientation (with respect to the chassis reference frame).

Parameters
[in]chassisassociated chassis subsystem
[in]locationlocation relative to the chassis frame
[in]rotationorientation relative to the chassis frame

Reimplemented from chrono::vehicle::ChSteering.

◆ InitializeInertiaProperties()

void chrono::vehicle::ChPitmanArm::InitializeInertiaProperties ( )
overrideprotectedvirtual

Initialize subsystem inertia properties.

Derived classes must override this function and set the subsystem mass (m_mass) and, if constant, the subsystem COM frame and its inertia tensor. This function is called during initialization of the vehicle system.

Implements chrono::vehicle::ChPart.

◆ SetVehicleFrameInertiaFlag()

void chrono::vehicle::ChPitmanArm::SetVehicleFrameInertiaFlag ( bool  val)
inlineprotected

Indicate whether or not inertia matrices are specified with respect to a vehicle-aligned centroidal frame (flag=true) or with respect to the body centroidal frame (flag=false).

Note that this function must be called before Initialize().

◆ Synchronize()

void chrono::vehicle::ChPitmanArm::Synchronize ( double  time,
const DriverInputs driver_inputs 
)
overridevirtual

Update the state of this steering subsystem at the current time.

The steering subsystem is provided the current steering driver input (a value between -1 and +1). Positive steering input indicates steering to the left. This function is called during the vehicle update.

Parameters
[in]timecurrent time
[in]driver_inputscurrent driver inputs

Implements chrono::vehicle::ChSteering.

◆ UpdateInertiaProperties()

void chrono::vehicle::ChPitmanArm::UpdateInertiaProperties ( )
overrideprotectedvirtual

Update subsystem inertia properties.

Derived classes must override this function and set the global subsystem transform (m_xform) and, unless constant, the subsystem COM frame (m_com) and its inertia tensor (m_inertia). Calculate the current inertia properties and global frame of this subsystem. This function is called every time the state of the vehicle system is advanced in time.

Implements chrono::vehicle::ChPart.


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