chrono::ChHydraulicActuator2 Class Reference

Description

Hydraulic actuator using a circuit with 2 volumes.

Schematic:

                 piston      rod
                  side      side
                ___________________
               |   1     |     2   |
 cylinder      |         |----------------
               |___^_____|_____^___|
                   |           |
                   |           |
                   | hose1     | hose2
                   |           |
                  _|___________|_
 directional     |       X       |
    valve        |___|____ __|___|
                     |       |
                   pump     tank

Components:

  • 1 pump and 1 tank, modeled as constant pressures
  • 2 hoses
  • 1 cylinder
  • 1 directional valve 4x3 States:
  • y(0): U – dvalve spool position
  • y(1): p1 – cylinder pressure 1 (piston-side)
  • y(2): p2 – cylinder pressure 2 (rod-side)

#include <ChHydraulicActuator.h>

Inheritance diagram for chrono::ChHydraulicActuator2:
Collaboration diagram for chrono::ChHydraulicActuator2:

Public Member Functions

void SetBulkModuli (double oil_bulk_modulus, double hose_bulk_modulus, double cyl_bulk_modulus)
 Set the bulk modulus for oil, hoses, and cylinder.
 
void SetHoseVolumes (double hose_dvalve_piston, double hose_dvalve_rod)
 Set the volumes of the two hoses in this circuit.
 
- Public Member Functions inherited from chrono::ChHydraulicActuatorBase
void SetInputFunction (std::shared_ptr< ChFunction > fun)
 Set the actuation function. More...
 
void SetPressures (double pump_pressure, double tank_pressure)
 Set the tank and pump pressures.
 
void SetActuatorInitialLength (double len)
 Set actuator initial length [m]. More...
 
void SetInitialLoad (double F0)
 Set initial loading force. More...
 
void Initialize ()
 Initialize the hydraulic actuator stand-alone. More...
 
void Initialize (std::shared_ptr< ChBody > body1, std::shared_ptr< ChBody > body2, bool local, ChVector3d loc1, ChVector3d loc2)
 Initialize this hydraulic actuator by connecting it between the two specified bodies. More...
 
ChHydraulicCylinderCylinder ()
 Access the hydraulic cylinder in this circuit.
 
ChHydraulicDirectionalValve4x3DirectionalValve ()
 Access the directoinal valve in this circuit.
 
ChVector3d GetPoint1Abs () const
 Get the endpoint location on 1st body (expressed in absolute coordinate system). More...
 
ChVector3d GetPoint2Abs () const
 Get the endpoint location on 2nd body (expressed in body coordinate system). More...
 
void SetActuatorLength (double len, double vel)
 Set the current actuator length and rate of change. More...
 
double GetActuatorForce ()
 Get the current actuator force. More...
 
std::array< double, 2 > GetCylinderPressures ()
 Get the current cylinder pressures.
 
double GetValvePosition ()
 Get the current directional valve position.
 
- Public Member Functions inherited from chrono::ChExternalDynamics
virtual ChExternalDynamicsClone () const override
 "Virtual" copy constructor (covariant return type).
 
ChVectorDynamic GetInitialStates ()
 Get the initial values (state at initial time).
 
const ChVectorDynamicGetStates () const
 Get current states.
 
const ChVectorDynamicGetRHS () const
 Get current RHS.
 
- Public Member Functions inherited from chrono::ChPhysicsItem
 ChPhysicsItem (const ChPhysicsItem &other)
 
ChSystemGetSystem () const
 Get the pointer to the parent ChSystem().
 
virtual void SetSystem (ChSystem *m_system)
 Set the pointer to the parent ChSystem(). More...
 
void AddVisualModel (std::shared_ptr< ChVisualModel > model)
 Add an (optional) visualization model. More...
 
std::shared_ptr< ChVisualModelGetVisualModel () const
 Access the visualization model (if any). More...
 
void AddVisualShape (std::shared_ptr< ChVisualShape > shape, const ChFrame<> &frame=ChFrame<>())
 Add the specified visual shape to the visualization model. More...
 
std::shared_ptr< ChVisualShapeGetVisualShape (unsigned int i) const
 Access the specified visualization shape in the visualization model (if any). More...
 
void AddVisualShapeFEA (std::shared_ptr< ChVisualShapeFEA > shapeFEA)
 Add the specified FEA visualization object to the visualization model. More...
 
std::shared_ptr< ChVisualShapeFEAGetVisualShapeFEA (unsigned int i) const
 Access the specified FEA visualization object in the visualization model (if any). More...
 
virtual ChFrame GetVisualModelFrame (unsigned int nclone=0) const
 Get the reference frame (expressed in and relative to the absolute frame) of the visual model. More...
 
virtual unsigned int GetNumVisualModelClones () const
 Return the number of clones of the visual model associated with this physics item. More...
 
void AddCamera (std::shared_ptr< ChCamera > camera)
 Attach a ChCamera to this physical item. More...
 
std::vector< std::shared_ptr< ChCamera > > GetCameras () const
 Get the set of cameras attached to this physics item.
 
virtual bool IsActive () const
 Return true if the object is active and included in dynamics.
 
virtual bool IsCollisionEnabled () const
 Tell if the object is subject to collision. More...
 
virtual void AddCollisionModelsToSystem (ChCollisionSystem *coll_sys) const
 Add to the provided collision system any collision models managed by this physics item. More...
 
virtual void RemoveCollisionModelsFromSystem (ChCollisionSystem *coll_sys) const
 Remove from the provided collision system any collision models managed by this physics item. More...
 
virtual void SyncCollisionModels ()
 Synchronize the position and bounding box of any collsion models managed by this physics item.
 
virtual ChAABB GetTotalAABB ()
 Get the entire AABB axis-aligned bounding box of the object. More...
 
virtual void GetCenter (ChVector3d &mcenter)
 Get a symbolic 'center' of the object. More...
 
virtual void Setup ()
 This might recompute the number of coordinates, DOFs, constraints, in case this might change (ex in ChAssembly), as well as state offsets of contained items (ex in ChMesh)
 
virtual void Update (bool update_assets=true)
 As above, but does not require updating of time-dependent data. More...
 
virtual void ForceToRest ()
 Set zero speed (and zero accelerations) in state, without changing the position. More...
 
virtual unsigned int GetNumCoordsVelLevel ()
 Get the number of coordinates at the velocity level. More...
 
virtual unsigned int GetNumConstraints ()
 Get the number of scalar constraints.
 
virtual unsigned int GetNumConstraintsBilateral ()
 Get the number of bilateral scalar constraints.
 
virtual unsigned int GetNumConstraintsUnilateral ()
 Get the number of unilateral scalar constraints.
 
unsigned int GetOffset_x ()
 Get offset in the state vector (position part)
 
unsigned int GetOffset_w ()
 Get offset in the state vector (speed part)
 
unsigned int GetOffset_L ()
 Get offset in the lagrangian multipliers.
 
void SetOffset_x (const unsigned int moff)
 Set offset in the state vector (position part) Note: only the ChSystem::Setup function should use this.
 
void SetOffset_w (const unsigned int moff)
 Set offset in the state vector (speed part) Note: only the ChSystem::Setup function should use this.
 
void SetOffset_L (const unsigned int moff)
 Set offset in the lagrangian multipliers Note: only the ChSystem::Setup function should use this.
 
virtual void IntStateGatherReactions (const unsigned int off_L, ChVectorDynamic<> &L)
 From item's reaction forces to global reaction vector. More...
 
virtual void IntStateScatterReactions (const unsigned int off_L, const ChVectorDynamic<> &L)
 From global reaction vector to item's reaction forces. More...
 
virtual void IntStateIncrement (const unsigned int off_x, ChState &x_new, const ChState &x, const unsigned int off_v, const ChStateDelta &Dv)
 Computes x_new = x + Dt , using vectors at specified offsets. More...
 
virtual void IntStateGetIncrement (const unsigned int off_x, const ChState &x_new, const ChState &x, const unsigned int off_v, ChStateDelta &Dv)
 Computes Dt = x_new - x, using vectors at specified offsets. More...
 
virtual void IntLoadResidual_CqL (const unsigned int off_L, ChVectorDynamic<> &R, const ChVectorDynamic<> &L, const double c)
 Takes the term Cq'*L, scale and adds to R at given offset: R += c*Cq'*L. More...
 
virtual void IntLoadConstraint_C (const unsigned int off, ChVectorDynamic<> &Qc, const double c, bool do_clamp, double recovery_clamp)
 Takes the term C, scale and adds to Qc at given offset: Qc += c*C. More...
 
virtual void IntLoadConstraint_Ct (const unsigned int off, ChVectorDynamic<> &Qc, const double c)
 Takes the term Ct, scale and adds to Qc at given offset: Qc += c*Ct. More...
 
virtual void InjectConstraints (ChSystemDescriptor &descriptor)
 Register with the given system descriptor any ChConstraint objects associated with this item.
 
virtual void LoadConstraintJacobians ()
 Compute and load current Jacobians in encapsulated ChConstraint objects.
 
virtual void ConstraintsBiReset ()
 Sets to zero the known term (b_i) of encapsulated ChConstraints.
 
virtual void ConstraintsBiLoad_C (double factor=1, double recovery_clamp=0.1, bool do_clamp=false)
 Adds the current C (constraint violation) to the known term (b_i) of encapsulated ChConstraints.
 
virtual void ConstraintsBiLoad_Ct (double factor=1)
 Adds the current Ct (partial t-derivative, as in C_dt=0-> [Cq]*q_dt=-Ct) to the known term (b_i) of encapsulated ChConstraints.
 
virtual void ConstraintsBiLoad_Qc (double factor=1)
 Adds the current Qc (the vector of C_dtdt=0 -> [Cq]*q_dtdt=Qc ) to the known term (b_i) of encapsulated ChConstraints.
 
virtual void ConstraintsFetch_react (double factor=1)
 Fetches the reactions from the lagrangian multiplier (l_i) of encapsulated ChConstraints. More...
 
virtual void ArchiveOut (ChArchiveOut &archive_out) override
 Method to allow serialization of transient data to archives.
 
virtual void ArchiveIn (ChArchiveIn &archive_in) override
 Method to allow deserialization of transient data from archives. More...
 
- Public Member Functions inherited from chrono::ChObj
 ChObj (const ChObj &other)
 
int GetIdentifier () const
 Get the unique integer identifier of this object. More...
 
void SetTag (int tag)
 Set an object integer tag (default: -1). More...
 
int GetTag () const
 Get the tag of this object.
 
void SetName (const std::string &myname)
 Set the name of this object.
 
const std::string & GetName () const
 Get the name of this object.
 
double GetChTime () const
 Gets the simulation time of this object.
 
void SetChTime (double m_time)
 Sets the simulation time of this object.
 
virtual std::string & ArchiveContainerName ()
 

Additional Inherited Members

- Protected Member Functions inherited from chrono::ChHydraulicActuatorBase
double GetInput (double t) const
 Get current actuator input.
 
virtual bool IsStiff () const override
 Declare the EOM of this physics item as stiff or non-stiff.
 
virtual void Update (double time, bool update_assets=true) override
 Update the physics item at current state.
 
virtual void IntLoadResidual_F (const unsigned int off, ChVectorDynamic<> &R, const double c) override
 Load generalized forces.
 
- Protected Member Functions inherited from chrono::ChExternalDynamics
virtual unsigned int GetNumCoordsPosLevel () override
 Get the number of coordinates at the position level. More...
 
ChVariablesVariables ()
 
virtual void InjectVariables (ChSystemDescriptor &descriptor) override
 Register with the given system descriptor any ChVariable objects associated with this item.
 
virtual void InjectKRMMatrices (ChSystemDescriptor &descriptor) override
 Register with the given system descriptor any ChKRMBlock objects associated with this item.
 
virtual void IntStateGather (const unsigned int off_x, ChState &x, const unsigned int off_v, ChStateDelta &v, double &T) override
 From item's state to global state vectors y={x,v} pasting the states at the specified offsets. More...
 
virtual void IntStateScatter (const unsigned int off_x, const ChState &x, const unsigned int off_v, const ChStateDelta &v, const double T, bool full_update) override
 From global state vectors y={x,v} to item's state (and update) fetching the states at the specified offsets. More...
 
virtual void IntStateGatherAcceleration (const unsigned int off_a, ChStateDelta &a) override
 From item's state acceleration to global acceleration vector. More...
 
virtual void IntStateScatterAcceleration (const unsigned int off_a, const ChStateDelta &a) override
 From global acceleration vector to item's state acceleration. More...
 
virtual void IntLoadResidual_Mv (const unsigned int off, ChVectorDynamic<> &R, const ChVectorDynamic<> &v, const double c) override
 Takes the M*v term, multiplying mass by a vector, scale and adds to R at given offset: R += c*M*w. More...
 
virtual void IntLoadLumpedMass_Md (const unsigned int off, ChVectorDynamic<> &Md, double &err, const double c) override
 Adds the lumped mass to a Md vector, representing a mass diagonal matrix. More...
 
virtual void IntToDescriptor (const unsigned int off_v, const ChStateDelta &v, const ChVectorDynamic<> &R, const unsigned int off_L, const ChVectorDynamic<> &L, const ChVectorDynamic<> &Qc) override
 Prepare variables and constraints to accommodate a solution: More...
 
virtual void IntFromDescriptor (const unsigned int off_v, ChStateDelta &v, const unsigned int off_L, ChVectorDynamic<> &L) override
 After a solver solution, fetch values from variables and constraints into vectors: More...
 
virtual void LoadKRMMatrices (double Kfactor, double Rfactor, double Mfactor) override
 Compute and load current stiffnes (K), damping (R), and mass (M) matrices in encapsulated ChKRMBlock objects. More...
 
virtual void VariablesFbReset () override
 Sets the 'fb' part (the known term) of the encapsulated ChVariables to zero.
 
virtual void VariablesFbLoadForces (double factor=1) override
 Adds the current forces (applied to item) into the encapsulated ChVariables, in the 'fb' part: qf+=forces*factor.
 
virtual void VariablesQbLoadSpeed () override
 Initialize the 'qb' part of the ChVariables with the current value of speeds. More...
 
virtual void VariablesQbSetSpeed (double step=0) override
 Fetches the item speed (ex. More...
 
virtual void VariablesFbIncrementMq () override
 Adds M*q (masses multiplied current 'qb') to Fb, ex. More...
 
virtual void VariablesQbIncrementPosition (double step) override
 Increment item positions by the 'qb' part of the ChVariables, multiplied by a 'step' factor. More...
 
virtual void ConstraintsFbLoadForces (double factor=1) override
 Adds the current link-forces, if any, (caused by springs, etc.) to the 'fb' vectors of the ChVariables referenced by encapsulated ChConstraints.
 
void ComputeJac (double time)
 Compute the Jacobian at the current time and state.
 
- Protected Member Functions inherited from chrono::ChObj
int GenerateUniqueIdentifier ()
 
- Protected Attributes inherited from chrono::ChHydraulicActuatorBase
bool is_attached
 true if actuator attached to bodies
 
ChBodym_body1
 first conected body
 
ChBodym_body2
 second connected body
 
ChVector3d m_loc1
 point on body 1 (local frame)
 
ChVector3d m_loc2
 point on body 2 (local frame)
 
ChVector3d m_aloc1
 point on body 1 (global frame)
 
ChVector3d m_aloc2
 point on body 2 (global frame)
 
ChVectorDynamic m_Qforce
 generalized forcing terms
 
ChHydraulicCylinder cyl
 hydraulic cylinder
 
ChHydraulicDirectionalValve4x3 dvalve
 directional valve
 
std::shared_ptr< ChFunctionref_fun
 actuation function (spool displacement reference)
 
double s_0
 initial actuator length [m]
 
double s
 current actuator length [m]
 
double sd
 current actuator speed [m/s]
 
double pP
 pump pressure [Pa]
 
double pT
 tank pressure [Pa]
 
bool calculate_consistent_IC
 solve initialization nonlinear system
 
double F0
 estimated initial load
 
- Protected Attributes inherited from chrono::ChPhysicsItem
ChSystemsystem
 parent system
 
std::shared_ptr< ChVisualModelInstancevis_model_instance
 instantiated visualization model
 
std::vector< std::shared_ptr< ChCamera > > cameras
 set of cameras
 
unsigned int offset_x
 offset in vector of state (position part)
 
unsigned int offset_w
 offset in vector of state (speed part)
 
unsigned int offset_L
 offset in vector of lagrangian multipliers
 
- Protected Attributes inherited from chrono::ChObj
double ChTime
 object simulation time
 
std::string m_name
 object name
 
int m_identifier
 object unique identifier
 
int m_tag
 user-supplied tag
 

The documentation for this class was generated from the following files:
  • /builds/uwsbel/chrono/src/chrono/physics/ChHydraulicActuator.h
  • /builds/uwsbel/chrono/src/chrono/physics/ChHydraulicActuator.cpp