chrono::vehicle::ChVehicleCosimTerrainNodeGranularGPU Class Reference


Definition of the GPU granular terrain node (using Chrono::Gpu).

#include <ChVehicleCosimTerrainNodeGranularGPU.h>

Inheritance diagram for chrono::vehicle::ChVehicleCosimTerrainNodeGranularGPU:
Collaboration diagram for chrono::vehicle::ChVehicleCosimTerrainNodeGranularGPU:

Public Member Functions

 ChVehicleCosimTerrainNodeGranularGPU (double length, double width)
 Create a Chrono::Granular terrain node.
 ChVehicleCosimTerrainNodeGranularGPU (const std::string &specfile)
 Create a Chrono::Granular terrain node and set parameters from the provided JSON specfile.
virtual ChSystemGetSystem () override
 Return a pointer to the underlying Chrono system.
void SetFromSpecfile (const std::string &specfile)
 Set full terrain specification from JSON specfile.
void SetGranularMaterial (double radius, double density)
 Set properties of granular material. More...
void SetMaterialSurface (const std::shared_ptr< ChMaterialSurfaceSMC > &mat)
 Set the material properties for terrain. More...
void SetTangentialDisplacementModel (gpu::CHGPU_FRICTION_MODE model)
 Set the normal contact force model (default: Hertz). /void SetContactForceModel(ChSystemSMC::ContactForceModel model);. More...
void SetSamplingMethod (utils::SamplingType type, double init_height, double sep_factor=1.001, bool in_layers=false)
 Set sampling method for generation of granular material. More...
void SetIntegratorType (gpu::CHGPU_TIME_INTEGRATOR type)
 Set the integrator type (default: CENTERED_DIFFERENCE)
void SetInputFromCheckpoint (const std::string &filename)
 Initialize granular terrain from the specified checkpoint file (which must exist in the output directory). More...
void SetSettlingTime (double time)
 Set simulation length for settling of granular material (default: 0.4).
void SetSettlingKineticEneryThreshold (double threshold)
 Set total kinetic energy threshold as stopping criteria for settling (default: 1e-3).
void EnableSettlingOutput (bool output, double output_fps=100)
 Enable/disable output during settling (default: false). More...
void Settle ()
 Obtain settled terrain configuration. More...
virtual void WriteCheckpoint (const std::string &filename) const override
 Write checkpoint to the specified file (which will be created in the output directory).
double CalculatePackingDensity (double &depth)
 Estimate packing density (eta) of granular material in current configuration. More...
virtual void OutputVisualizationData (int frame) override final
 Output post-processing visualization data.
- 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.
- 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 of Chrono terrain. More...
- Public Types inherited from chrono::vehicle::ChVehicleCosimBaseNode
enum  NodeType { NodeType::MBS_WHEELED, NodeType::MBS_TRACKED, 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< ProxyBodyProxies
- 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_objects) override
 Initialize this Chrono terrain node. More...
virtual void CreateMeshProxy (unsigned int i)
 Create the i-th proxy mesh. 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 UpdateMeshProxy (unsigned int i, MeshState &mesh_state)
 Update the state of the i-th proxy mesh. More...
virtual void GetForceMeshProxy (unsigned int i, MeshContact &mesh_contact)
 Collect cumulative contact forces on the i-th proxy mesh. More...
- Protected Member Functions inherited from chrono::vehicle::ChVehicleCosimBaseNode
 ChVehicleCosimBaseNode (const std::string &name)
void SendGeometry (const ChVehicleGeometry &geom, int dest) const
void RecvGeometry (ChVehicleGeometry &geom, int source) const
- Protected Attributes inherited from chrono::vehicle::ChVehicleCosimTerrainNodeChrono
Type m_type
 terrain type
ChContactMethod m_method
 contact method (SMC or NSC)
std::shared_ptr< ChMaterialSurfacem_material_terrain
 material properties for terrain bodies
double m_init_height
 terrain initial height
std::vector< Proxies > m_proxies
 proxy bodies for each object
bool m_fixed_proxies
 are proxy bodies fixed to ground?
std::vector< RigidObstaclem_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)
bool m_wheeled
 comm node (true: TIRE nodes, false: tracked MBS node)
InterfaceType m_interface_type
 communication interface (body or mesh)
int m_num_objects
 number of interacting objects
std::vector< ChVehicleGeometry::AABB > m_aabb
 AABB of collision models for interacting objects.
std::vector< ChVehicleGeometrym_geometry
 contact geometry and materials for interacting objects
std::vector< double > m_load_mass
 vertical load on interacting objects
std::vector< int > m_obj_map
 mapping from interacting object to shape
std::vector< MeshState > m_mesh_state
 mesh state (used for MESH communication)
std::vector< BodyStatem_rigid_state
 rigid state (used for BODY communication interface)
std::vector< MeshContactm_mesh_contact
 mesh contact forces (used for MESH communication interface)
std::vector< TerrainForcem_rigid_contact
 rigid contact force (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_wheeled_mbs_nodes
unsigned int m_num_tracked_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

◆ CalculatePackingDensity()

double chrono::vehicle::ChVehicleCosimTerrainNodeGranularGPU::CalculatePackingDensity ( double &  depth)

Estimate packing density (eta) of granular material in current configuration.

Note that porosity is phi=1-eta and void ratio is e=(1-eta)/eta=phi/(1-phi). The function also returns the current depth of granular material.

◆ EnableSettlingOutput()

void chrono::vehicle::ChVehicleCosimTerrainNodeGranularGPU::EnableSettlingOutput ( bool  output,
double  output_fps = 100 

Enable/disable output during settling (default: false).

If enabled, output files are generated with the specified frequency.

◆ SetGranularMaterial()

void chrono::vehicle::ChVehicleCosimTerrainNodeGranularGPU::SetGranularMaterial ( double  radius,
double  density 

Set properties of granular material.

radiusparticle radius (default: 0.01)
densityparticle material density (default: 2000)

◆ SetInputFromCheckpoint()

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

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

By default, particles are created uniformly distributed in the specified domain such that they are initially not in contact.

◆ SetMaterialSurface()

void chrono::vehicle::ChVehicleCosimTerrainNodeGranularGPU::SetMaterialSurface ( const std::shared_ptr< ChMaterialSurfaceSMC > &  mat)

Set the material properties for terrain.

These parameters characterize the material for the container and the granular material. Object contact material is received from the rig node.

◆ SetSamplingMethod()

void chrono::vehicle::ChVehicleCosimTerrainNodeGranularGPU::SetSamplingMethod ( utils::SamplingType  type,
double  init_height,
double  sep_factor = 1.001,
bool  in_layers = false 

Set sampling method for generation of granular material.

The granular material is created in the volume defined by the x-y dimensions of the terrain patch and the specified initial height, using the specified sampling type, layer by layer or all at once. Note: for correct HCP, do not initialize in layers!

typevolume sampling type (default POISSON_DISK)
init_heightheight of granular material at initialization (default 0.2)
sep_factorradius inflation factor for initial separation
in_layersinitialize material in layers

◆ SetTangentialDisplacementModel()

void chrono::vehicle::ChVehicleCosimTerrainNodeGranularGPU::SetTangentialDisplacementModel ( gpu::CHGPU_FRICTION_MODE  model)

Set the normal contact force model (default: Hertz). /void SetContactForceModel(ChSystemSMC::ContactForceModel model);.

Set the tangential contact displacement model (default: SINGLE_STEP).

◆ Settle()

void chrono::vehicle::ChVehicleCosimTerrainNodeGranularGPU::Settle ( )

Obtain settled terrain configuration.

This is an optional operation that can be performed for granular terrain before initiating communictation with the rig node. For granular terrain, a settled configuration can be obtained either through simulation or by initializing particles from a previously generated checkpointing file.

The documentation for this class was generated from the following files:
  • /builds/uwsbel/chrono/src/chrono_vehicle/cosim/terrain/ChVehicleCosimTerrainNodeGranularGPU.h
  • /builds/uwsbel/chrono/src/chrono_vehicle/cosim/terrain/ChVehicleCosimTerrainNodeGranularGPU.cpp