Base class for a tracked vehicle sprocket.

A sprocket is responsible for contact processing with the track shoes of the containing track assembly.

#include <ChSprocket.h>

Inheritance diagram for chrono::vehicle::ChSprocket:
Collaboration diagram for chrono::vehicle::ChSprocket:

Public Member Functions

 ChSprocket (const std::string &name)
virtual int GetNumTeeth () const =0
 Get the number of teeth of the gear.
virtual double GetAssemblyRadius () const =0
 Get the track assembly radius. More...
std::shared_ptr< ChBodyGetGearBody () const
 Get a handle to the gear body.
std::shared_ptr< ChShaftGetAxle () const
 Get a handle to the axle shaft.
< ChLinkLockRevolute
GetRevolute () const
 Get a handle to the revolute joint.
double GetAxleSpeed () const
 Get the angular speed of the axle.
void SetContactFrictionCoefficient (float friction_coefficient)
 Set coefficient of friction. More...
void SetContactRestitutionCoefficient (float restitution_coefficient)
 Set coefficient of restiturion. More...
void SetContactMaterialProperties (float young_modulus, float poisson_ratio)
 Set contact material properties. More...
void SetContactMaterialCoefficients (float kn, float gn, float kt, float gt)
 Set contact material coefficients. More...
float GetCoefficientFriction () const
 Get coefficient of friction for contact material.
float GetCoefficientRestitution () const
 Get coefficient of restitution for contact material.
float GetYoungModulus () const
 Get Young's modulus of elasticity for contact material.
float GetPoissonRatio () const
 Get Poisson ratio for contact material.
float GetKn () const
 Get normal stiffness coefficient for contact material.
float GetKt () const
 Get tangential stiffness coefficient for contact material.
float GetGn () const
 Get normal viscous damping coefficient for contact material.
float GetGt () const
 Get tangential viscous damping coefficient for contact material.
void SetCollide (bool val)
 Turn on/off collision flag for the gear wheel.
virtual double GetMass () const
 Get the mass of the sprocket subsystem.
void Initialize (std::shared_ptr< ChBodyAuxRef > chassis, const ChVector<> &location, ChTrackAssembly *track)
 Initialize this sprocket subsystem. More...
void ApplyAxleTorque (double torque)
 Apply the provided motor torque. More...
virtual void AddVisualizationAssets (VisualizationType vis) override
 Add visualization assets for the sprocket subsystem.
virtual void RemoveVisualizationAssets () overridefinal
 Remove visualization assets for the sprocket subsystem.
void LogConstraintViolations ()
 Log current constraint violations.
- Public Member Functions inherited from chrono::vehicle::ChPart
 ChPart (const std::string &name)
 Construct a vehicle subsystem with the specified name. More...
const std::string & GetName () const
 Get the name identifier for this track shoe subsystem.
void SetName (const std::string &name)
 Set the name identifier for this track shoe subsystem.
void SetVisualizationType (VisualizationType vis)
 Set the visualization mode for this subsystem.

Protected Member Functions

virtual double GetGearMass () const =0
 Return the mass of the gear body.
virtual const ChVectorGetGearInertia ()=0
 Return the moments of inertia of the gear body.
virtual double GetAxleInertia () const =0
 Return the inertia of the axle shaft.
virtual double GetSeparation () const =0
 Return the distance between the two gear profiles.
virtual std::shared_ptr
< geometry::ChLinePath
GetProfile ()=0
 Return the 2D gear profile. More...
GetCollisionCallback (ChTrackAssembly *track)=0
 Return the custom collision callback object. More...

Protected Attributes

std::shared_ptr< ChBodym_gear
 handle to the sprocket gear body
std::shared_ptr< ChShaftm_axle
 handle to gear shafts
std::shared_ptr< ChShaftsBodym_axle_to_spindle
 handle to gear-shaft connector
< ChLinkLockRevolute
 handle to sprocket revolute joint
 custom collision functor object
float m_friction
 contact coefficient of friction
float m_restitution
 contact coefficient of restitution
float m_young_modulus
 contact material Young modulus
float m_poisson_ratio
 contact material Poisson ratio
float m_kn
 normal contact stiffness
float m_gn
 normal contact damping
float m_kt
 tangential contact stiffness
float m_gt
 tangential contact damping
- Protected Attributes inherited from chrono::vehicle::ChPart
std::string m_name

Constructor & Destructor Documentation

chrono::vehicle::ChSprocket::ChSprocket ( const std::string &  name)
[in]namename of the subsystem

Member Function Documentation

void chrono::vehicle::ChSprocket::ApplyAxleTorque ( double  torque)

Apply the provided motor torque.

The given torque is applied to the axle. This function provides the interface to the drivetrain subsystem (intermediated by the vehicle system).

[in]torquevalue of applied torque
virtual double chrono::vehicle::ChSprocket::GetAssemblyRadius ( ) const
pure virtual

Get the track assembly radius.

This quantity is used during the automatic track assembly. It represents a safe distance from the sprocket gear center at which the track shoes can be instantiated.

Implemented in chrono::vehicle::SprocketDoublePin, and chrono::vehicle::SprocketSinglePin.

virtual ChSystem::ChCustomComputeCollisionCallback* chrono::vehicle::ChSprocket::GetCollisionCallback ( ChTrackAssembly track)
protectedpure virtual

Return the custom collision callback object.

Note that the derived need not delete this object (it is deleted in the destructor of this base class).

[in]trackpointer to containing track assembly

Implemented in chrono::vehicle::ChSprocketDoublePin, and chrono::vehicle::ChSprocketSinglePin.

virtual std::shared_ptr<geometry::ChLinePath> chrono::vehicle::ChSprocket::GetProfile ( )
protectedpure virtual

Return the 2D gear profile.

The gear profile, a ChLinePath geometric object, is made up of an arbitrary number of sub-paths of type ChLineArc or ChLineSegment sub-lines. These must be added in clockwise order, and the end of sub-path i must be coincident with beginning of sub-path i+1.

Implemented in chrono::vehicle::ChSprocketDoublePin, and chrono::vehicle::ChSprocketSinglePin.

void chrono::vehicle::ChSprocket::Initialize ( std::shared_ptr< ChBodyAuxRef chassis,
const ChVector<> &  location,
ChTrackAssembly track 

Initialize this sprocket subsystem.

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

[in]chassishandle to the chassis body
[in]locationlocation relative to the chassis frame
[in]trackpointer to containing track assembly
void chrono::vehicle::ChSprocket::SetContactFrictionCoefficient ( float  friction_coefficient)

Set coefficient of friction.

The default value is 0.4

void chrono::vehicle::ChSprocket::SetContactMaterialCoefficients ( float  kn,
float  gn,
float  kt,
float  gt 

Set contact material coefficients.

These values are used directly to compute contact forces (if the containing system is so configured and if the DEM-P contact method is being used). The default values are: kn=2e5, gn=40, kt=2e5, gt=20

[in]knnormal contact stiffness
[in]gnnormal contact damping
[in]kttangential contact stiffness
[in]gttangential contact damping
void chrono::vehicle::ChSprocket::SetContactMaterialProperties ( float  young_modulus,
float  poisson_ratio 

Set contact material properties.

These values are used to calculate contact material coefficients (if the containing system is so configured and if the DEM-P contact method is being used). The default values are: Y = 1e7 and nu = 0.3

[in]young_modulusYoung's modulus of elasticity
[in]poisson_ratioPoisson ratio
void chrono::vehicle::ChSprocket::SetContactRestitutionCoefficient ( float  restitution_coefficient)

Set coefficient of restiturion.

The default value is 0.1