Drake

A class to hold a set of forces applied to a MultibodyTree system. More...
#include <drake/multibody/multibody_tree/multibody_forces.h>
Public Member Functions  
MultibodyForces (const MultibodyTree< T > &model)  
Constructs a force object to store a set of forces to be applied to model . More...  
MultibodyForces< T > &  SetZero () 
Sets this to store zero forces (no applied forces). More...  
int  num_bodies () const 
Returns the number of bodies for which this force object applies. More...  
int  num_velocities () const 
Returns the number of generalized velocities for the model to which these forces apply. More...  
const VectorX< T > &  generalized_forces () const 
Returns a constant reference to the vector of generalized forces stored by this forces object. More...  
VectorX< T > &  mutable_generalized_forces () 
Mutable version of generalized_forces(). More...  
const std::vector< SpatialForce< T > > &  body_forces () const 
Returns a constant reference to the vector of spatial body forces F_BBo_W on each body B in the model, at the body's frame origin Bo , expressed in the world frame W. More...  
std::vector< SpatialForce< T > > &  mutable_body_forces () 
Mutable version of body_forces(). More...  
void  AddInForces (const MultibodyForces< T > &addend) 
Adds into this the force contribution stored in addend . More...  
bool  CheckHasRightSizeForModel (const MultibodyTree< T > &model) const 
Utility that checks that the forces stored by this object have the proper sizes to represent the set of forces for the given model . More...  
Implements CopyConstructible, CopyAssignable, MoveConstructible, MoveAssignable  
MultibodyForces (const MultibodyForces &)=default  
MultibodyForces &  operator= (const MultibodyForces &)=default 
MultibodyForces (MultibodyForces &&)=default  
MultibodyForces &  operator= (MultibodyForces &&)=default 
A class to hold a set of forces applied to a MultibodyTree system.
Forces can include generalized forces as well as body spatial forces.
T  The scalar type. Must be a valid Eigen scalar. 
Instantiated templates for the following kinds of T's are provided:
They are already available to link against in the containing library. No other values for T are currently supported.

default 

default 

explicit 
Constructs a force object to store a set of forces to be applied to model
.
Forces are initialized to zero, meaning no forces are applied to model
. model
must have been already finalized with MultibodyTree::Finalize() or this constructor will abort.
void AddInForces  (  const MultibodyForces< T > &  addend  ) 
Adds into this
the force contribution stored in addend
.

inline 
Returns a constant reference to the vector of spatial body forces F_BBo_W
on each body B in the model, at the body's frame origin Bo
, expressed in the world frame W.
bool CheckHasRightSizeForModel  (  const MultibodyTree< T > &  model  )  const 
Utility that checks that the forces stored by this
object have the proper sizes to represent the set of forces for the given model
.
this
forces object has the proper sizes for the given model
. Returns a constant reference to the vector of generalized forces stored by this
forces object.

inline 
Mutable version of body_forces().
Mutable version of generalized_forces().

inline 
Returns the number of bodies for which this
force object applies.
Determined at construction from the given model MultibodyTree object.

inline 
Returns the number of generalized velocities for the model to which these forces apply.
The number of generalized forces in a multibody model always equals the number of generalized velocities. Determined at construction from the given model MultibodyTree object.

default 

default 
MultibodyForces< T > & SetZero  (  ) 
Sets this
to store zero forces (no applied forces).