Description

Definition of the SCM deformable terrain node.

#include <ChVehicleCosimTerrainNodeSCM.h>

Inheritance diagram for chrono::vehicle::ChVehicleCosimTerrainNodeSCM:

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Collaboration diagram for chrono::vehicle::ChVehicleCosimTerrainNodeSCM:

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Public Member Functions
	ChVehicleCosimTerrainNodeSCM (double length, double width)
	Create an SCM terrain node. Note that no SCM parameters are set.

	ChVehicleCosimTerrainNodeSCM (const std::string &specfile)
	Create an SCM terrain node using parameters from the provided JSON specfile.

virtual ChSystem *	GetSystem () override
	Return a pointer to the underlying Chrono system.

void	SetFromSpecfile (const std::string &specfile)
	Set full terrain specification from JSON specfile.

void	SetPropertiesSCM (double spacing, double Bekker_Kphi, double Bekker_Kc, double Bekker_n, double Mohr_cohesion, double Mohr_friction, double Janosi_shear, double elastic_K, double damping_R)
	Set the SCM material properties for terrain. More...

void	SetNumThreads (int num_threads)
	Set the number of OpenMP threads for SCM ray-casting (default: 1).

void	SetProxyContactRadius (double radius)
	Set sweeping sphere radius for proxy bodies (default 5e-3). More...

void	SetInputFromCheckpoint (const std::string &filename)
	Initialize SCM terrain from the specified checkpoint file (which must exist in the output directory). More...

virtual void	WriteCheckpoint (const std::string &filename) const override
	Write checkpoint to the specified file (which will be created in the output directory).

Public Member Functions inherited from chrono::vehicle::ChVehicleCosimTerrainNodeChrono
Type	GetType () const
	Return the type of this terrain node.

void	SetProxyFixed (bool fixed)
	Set the proxy bodies as fixed to ground.

virtual double	GetInitHeight () const override final
	Return the terrain initial height.

void	AddRigidObstacle (const RigidObstacle &obstacle)
	Add a rigid obstacle.

Public Member Functions inherited from chrono::vehicle::ChVehicleCosimTerrainNode
virtual NodeType	GetNodeType () const override
	Return the node type as NodeType::TERRAIN.

void	EnableRuntimeVisualization (bool render, double render_fps=100)
	Enable/disable run-time visualization (default: false). More...

void	SetDimensions (double length, double width)
	Set the terrain patch dimensions. More...

virtual void	Initialize () override final
	Initialize this node. More...

virtual void	Synchronize (int step_number, double time) override final
	Synchronize this node. More...

virtual void	Advance (double step_size) override final
	Advance simulation. More...

virtual void	OutputData (int frame) override final
	Output logging and debugging data.

virtual void	OutputVisualizationData (int frame) override
	Output post-processing visualization data. More...

virtual int	GetNumContacts () const
	Return current number of contacts. More...

Public Member Functions inherited from chrono::vehicle::ChVehicleCosimBaseNode
std::string	GetNodeTypeString () const
	Return the node type as a string.

bool	IsCosimNode () const
	Return true if this node is part of the co-simulation infrastructure.

void	SetStepSize (double step)
	Set the integration step size (default: 1e-4).

double	GetStepSize () const
	Get the integration step size.

void	SetOutDir (const std::string &dir_name, const std::string &suffix)
	Set the name of the output directory and an identifying suffix. More...

void	SetVerbose (bool verbose)
	Enable/disable verbose messages during simulation (default: true).

const std::string &	GetOutDirName () const
	Get the output directory name for this node.

double	GetStepExecutionTime () const
	Get the simulation execution time for the current step on this node. More...

double	GetTotalExecutionTime () const
	Get the cumulative simulation execution time on this node.

Additional Inherited Members
Public Types inherited from chrono::vehicle::ChVehicleCosimTerrainNodeChrono
enum	Type { Type::RIGID, Type::SCM, Type::GRANULAR_OMP, Type::GRANULAR_GPU, Type::GRANULAR_MPI, Type::GRANULAR_SPH, Type::UNKNOWN }
	Type of Chrono terrain. More...

Public Types inherited from chrono::vehicle::ChVehicleCosimBaseNode
enum	NodeType { NodeType::MBS, NodeType::TERRAIN, NodeType::TIRE }
	Type of node participating in co-simulation. More...

enum	InterfaceType { InterfaceType::BODY, InterfaceType::MESH }
	Type of the tire-terrain communication interface. More...

Static Public Member Functions inherited from chrono::vehicle::ChVehicleCosimTerrainNodeChrono
static std::string	GetTypeAsString (Type type)
	Return a string describing the type of this terrain node.

static Type	GetTypeFromString (const std::string &type)
	Infer the terrain node type from the given string.

static bool	ReadSpecfile (const std::string &specfile, rapidjson::Document &d)
	Read a JSON specification file for a Chrono terrain node.

static Type	GetTypeFromSpecfile (const std::string &specfile)
	Get the terrain type from the given JSON specification file.

static ChVector2	GetSizeFromSpecfile (const std::string &specfile)
	Get the terrain dimensions (length and width) from the given JSON specification file.

Static Public Member Functions inherited from chrono::vehicle::ChVehicleCosimBaseNode
static std::string	OutputFilename (const std::string &dir, const std::string &root, const std::string &ext, int frame, int frame_digits)
	Utility function for creating an output file name. More...

Protected Types inherited from chrono::vehicle::ChVehicleCosimTerrainNodeChrono
typedef std::vector< ProxyBody >	Proxies

Protected Member Functions inherited from chrono::vehicle::ChVehicleCosimTerrainNodeChrono
	ChVehicleCosimTerrainNodeChrono (Type type, double length, double width, ChContactMethod method)
	Construct a base class terrain node. More...

virtual void	OnInitialize (unsigned int num_tires) override
	Initialize this Chrono terrain node. More...

virtual void	OnAdvance (double step_size) override
	Advance simulation. More...

Protected Member Functions inherited from chrono::vehicle::ChVehicleCosimTerrainNode
	ChVehicleCosimTerrainNode (double length, double width)
	Construct a terrain node to wrap a terrain patch of given length and width.

virtual void	OnSynchronize (int step_number, double time)
	Perform any additional operations after the data exchange and synchronization with the MBS node. More...

virtual void	UpdateMeshProxies (unsigned int i, MeshState &mesh_state)
	Update the state of all proxy bodies for the i-th tire mesh. More...

Protected Member Functions inherited from chrono::vehicle::ChVehicleCosimBaseNode
	ChVehicleCosimBaseNode (const std::string &name)

Protected Attributes inherited from chrono::vehicle::ChVehicleCosimTerrainNodeChrono
Type	m_type
	terrain type

ChContactMethod	m_method
	contact method (SMC or NSC)

std::shared_ptr< ChMaterialSurface >	m_material_terrain
	material properties for terrain bodies

double	m_init_height
	terrain initial height

std::vector< Proxies >	m_proxies
	proxy bodies for each tire

bool	m_fixed_proxies
	are proxy bodies fixed to ground?

std::vector< RigidObstacle >	m_obstacles
	list of rigid obstacles

Protected Attributes inherited from chrono::vehicle::ChVehicleCosimTerrainNode
bool	m_render
	if true, perform run-time rendering

double	m_render_step
	time step between rendered frames

double	m_hdimX
	patch half-length (X direction)

double	m_hdimY
	patch half-width (Y direction)

InterfaceType	m_interface_type
	type of communication interface

std::vector< double >	m_tire_radius
	tire radius

std::vector< double >	m_tire_width
	tire width

std::vector< double >	m_load_mass
	vertical load on tire

std::vector< MaterialInfo >	m_mat_props
	tire contact material properties

std::vector< MeshData >	m_mesh_data
	tire mesh data

std::vector< MeshState >	m_mesh_state
	tire mesh state (used for MESH communication)

std::vector< BodyState >	m_spindle_state
	spindle state (used for BODY communication interface)

Protected Attributes inherited from chrono::vehicle::ChVehicleCosimBaseNode
int	m_rank
	MPI rank of this node (in MPI_COMM_WORLD)

double	m_step_size
	integration step size

std::string	m_name
	name of the node

std::string	m_out_dir
	top-level output directory

std::string	m_node_out_dir
	node-specific output directory

std::ofstream	m_outf
	output file stream

unsigned int	m_num_mbs_nodes

unsigned int	m_num_terrain_nodes

unsigned int	m_num_tire_nodes

ChTimer< double >	m_timer
	timer for integration cost

double	m_cum_sim_time
	cumulative integration cost

bool	m_verbose
	verbose messages during simulation?

Static Protected Attributes inherited from chrono::vehicle::ChVehicleCosimBaseNode
static const double	m_gacc = -9.81

Member Function Documentation

◆ SetInputFromCheckpoint()

void chrono::vehicle::ChVehicleCosimTerrainNodeSCM::SetInputFromCheckpoint ( const std::string & filename )

Initialize SCM terrain from the specified checkpoint file (which must exist in the output directory).

By default, a flat rectangular SCM terrain patch is used.

◆ SetPropertiesSCM()

void chrono::vehicle::ChVehicleCosimTerrainNodeSCM::SetPropertiesSCM	(	double	spacing,
		double	Bekker_Kphi,
		double	Bekker_Kc,
		double	Bekker_n,
		double	Mohr_cohesion,
		double	Mohr_friction,
		double	Janosi_shear,
		double	elastic_K,
		double	damping_R
	)

Set the SCM material properties for terrain.

Parameters

spacing	SCM grid spacing
Bekker_Kphi	Kphi, frictional modulus in Bekker model
Bekker_Kc	Kc, cohesive modulus in Bekker model
Bekker_n	n, exponent of sinkage in Bekker model (usually 0.6...1.8)
Mohr_cohesion	cohesion [Pa], for shear failure
Mohr_friction	Friction angle [degrees], for shear failure
Janosi_shear	shear parameter J [m], (usually a few mm or cm)
elastic_K	elastic stiffness K per unit area, [Pa/m] (must be larger than Kphi)
damping_R	vertical damping R per unit area [Pa.s/m] (proportional to vertical speed)

◆ SetProxyContactRadius()

void chrono::vehicle::ChVehicleCosimTerrainNodeSCM::SetProxyContactRadius ( double radius )

inline

Set sweeping sphere radius for proxy bodies (default 5e-3).

This value is used as a "thickness" for collision meshes (a non-zero value can improve robustness of the collision detection algorithm).

The documentation for this class was generated from the following files:

/builds/uwsbel/chrono/src/chrono_vehicle/cosim/terrain/ChVehicleCosimTerrainNodeSCM.h
/builds/uwsbel/chrono/src/chrono_vehicle/cosim/terrain/ChVehicleCosimTerrainNodeSCM.cpp

Description

Public Member Functions

Additional Inherited Members

Member Function Documentation

◆ SetInputFromCheckpoint()

◆ SetPropertiesSCM()

◆ SetProxyContactRadius()