Class: wsim.linearPowerTakeOff
==============================


.. code-block:: none

   wsim.linearPowerTakeOff is a class representing a linear power-take-off
   mechanism in a wave energy converter. It facilitates sending the correct
   forces to an MBDyn multibody simulation. wsim.linearPowerTakeOff applies
   forces between two MBDyn nodes based on their relative displacement.
   Forces are applied based on the relative displacement and velocity of the
   two nodes along axis 3 in the reference frame of the first node. It is
   assumed that the nodes motion is constrained appropriately by other MBDyn
   elements (e.g. a prismatic joint).
  
   wsim.linearPowerTakeOff Methods:
  
     linearPowerTakeOff - construct a wsim.linearPowerTakeOff object
     forceAndMoment - returns the forces and moments applied by the PTO in 3D
  
     Inheirited Methods
  
     advanceStep - advance to the next simulation time step
     logData - appends the internal variable data to the log
     loggingSetup - sets up data logging for a wsim.linearPowerTakeOff object
  
  

Inheiritance Graph
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.. graphviz::

   digraph graph_for_linearPowerTakeOff {
      "handle" -> "wsim.powerTakeOff" -> "wsim.linearPowerTakeOff";
   }

Parent Class Properties and Methods
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handle
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Inheirited Properties
""""""""""""""""""""""""""""""""""""""""""""""""""

None

Inheirited Methods
""""""""""""""""""""""""""""""""""""""""""""""""""

* addlistener : *ADDLISTENER  Add listener for event.*
* addlistener : *ADDLISTENER  Add listener for event.*
* addlistener : *ADDLISTENER  Add listener for event.*
* addlistener : *ADDLISTENER  Add listener for event.*
* addlistener : *ADDLISTENER  Add listener for event.*
* delete : *DELETE   Delete a handle object.*
* eq : *== (EQ)   Test handle equality.*
* findobj : *FINDOBJ   Find objects matching specified conditions.*
* findprop : *FINDPROP   Find property of MATLAB handle object.*
* ge : *>= (GE)   Greater than or equal relation for handles.*
* gt : *> (GT)   Greater than relation for handles.*
* isvalid : *ISVALID   Test handle validity.*
* le : *<= (LE)   Less than or equal relation for handles.*
* listener : *LISTENER  Add listener for event without binding the listener to the source object.*
* listener : *LISTENER  Add listener for event without binding the listener to the source object.*
* listener : *LISTENER  Add listener for event without binding the listener to the source object.*
* listener : *LISTENER  Add listener for event without binding the listener to the source object.*
* listener : *LISTENER  Add listener for event without binding the listener to the source object.*
* lt : *< (LT)   Less than relation for handles.*
* ne : *~= (NE)   Not equal relation for handles.*
* notify : *NOTIFY   Notify listeners of event.*
* notify : *NOTIFY   Notify listeners of event.*


wsim.powerTakeOff
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Inheirited Properties
""""""""""""""""""""""""""""""""""""""""""""""""""

* id
* loggingInfo
* loggingOn
* otherNode
* referenceNode
* uniqueLoggingNames


Inheirited Methods
""""""""""""""""""""""""""""""""""""""""""""""""""

* powerTakeOff : *wsim.powerTakeOff constructor*
* advanceStep : *advance to the next simulation time step*
* finish : *method called at end of wecSim simulation*
* forceAndMoment : *forceAndMoment should return the force and moment from a PTO*
* logData : *appends the internal variable data to the log*
* loggingSetup : *sets up data logging for a wsim.linearPowerTakeOff object*
* start : *initialise the pto simulation*


Properties
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No public properties

Methods
-------
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* linearPowerTakeOff
* forceAndMoment


linearPowerTakeOff
^^^^^^^^^^^^^^^^^^

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Summary
""""""""""""""""""""

construct a wsim.linearPowerTakeOff object


Syntax
""""""""""""""""""""

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   lpto = wsim.linearPowerTakeOff (reference_node, other_node, axisNum, force_fcn)
   lpto = wsim.linearPowerTakeOff (..., 'Parameter', value)
  

Description
""""""""""""""""""""

.. code-block:: none

   wsim.linearPowerTakeOff is a class representing a linear
   power-take-off mechanism in a wave energy converter. It
   facilitates sending the correct forces to an MBDyn multibody
   simulation. wsim.linearPowerTakeOff applies forces between
   two MBDyn nodes based on their relative displacement. Forces
   are applied based on the relative displacement and velocity
   of the two nodes along axis 3 in the reference frame of the
   first node. It is assumed that the nodes motion is
   constrained appropriately by other MBDyn elements (e.g. a
   prismatic joint).
  
   wsim.linearPowerTakeOff Methods:
  
    wsim.linearPowerTakeOff - constructor
    forceAndMoment - returns pto forces and moments on the 
      attached nodes
  

Inputs
""""""""""""""""""""

reference_node
""""""""""""""

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   mbdyn.pre.structuralNode6dof object


other_node
""""""""""

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   mbdyn.pre.structuralNode6dof object


axisNum
"""""""

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   axis in the frame of the reference node. Forces
   will be applied to the node in a direction parallel to this
   axis.
   


force_fcn
"""""""""

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   function handle or string to be used to
   calculate the force to be applied between the two nodes
   making up the PTO. force_fcn is a function which takes two
   arguments with the following signature:
   
        force_value = myfcn (time, reldisp, relvel)
   
   where time is the current simulation time, reldisp is the
   relative displacement of the two nodes along the specified
   axis in axisNum in the reference frame of the reference
   node, and relvel is the relative velocity of the two nodes
   in the same frame. force_value is expected to be a scalar
   value, the value of the force acting on the reference node
   parallel to the axis in forceAxis in the frame of the
   reference node.
   


Additional arguments may be supplied as parameter-value pairs:


InitialDisplacementZero
"""""""""""""""""""""""

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   optional true/false flag
   indicating whether the intial relative displacement (along
   axis 3 of the reference node) in the global frame should
   be taken as the reference point for displacement during
   the simulation, i.e. the PTO starts with an initial
   displacement of zero for the purposes of force calulation,
   and future displacement is measured relative to this
   initial position. If false, the raw position is used
   instead. Default is true if not supplied.
   


LoggedVars
""""""""""

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   character vector, or cell array of character
   vectors indicating what internal variables are to be
   logged during a simulation. If a character vector, it must
   be 'none', meaning nothing will be logged. Otherwise it
   must be a cell array containing any combination of the
   following names:
   


InternalForce
"""""""""""""

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   This is the internal PTO force
   calculated using the function supplied in force_fcn
   


RelativeDisplacement
""""""""""""""""""""

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   The relative displacement used to 
   calculate the PTO force
   


RelativeVelocity
""""""""""""""""

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   The relative velocity used to 
   calculate the PTO force
   


Outputs
""""""""""""""""""""

lpto
""""

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   a wsim.linearPowerTakeOff object



See Also
""""""""""""""""""""

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forceAndMoment
^^^^^^^^^^^^^^

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Summary
""""""""""""""""""""

returns the forces and moments applied by the PTO in 3D


Syntax
""""""""""""""""""""

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   [FM, ptotorque, reltheta, relomega] = forceAndMoment (rot)
  

Description
""""""""""""""""""""

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   wsim.linearPowerTakeOff.forceAndMoment calculates the forces
   and moments applied in the global frame by the PTO to the two
   nodes associated with the PTO.
  

Inputs
""""""""""""""""""""

rot
"""

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   wsim.rotaryPowerTakeOff object


Outputs
""""""""""""""""""""

FM
""

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   (6 x 2) vector of forces and moments in the global
   frame which the PTO is applying to the two nodes. The first
   column is the forces applied to the reference node, the
   second column is the forces and moments applied to the
   other node.
   


ptoforce
""""""""

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   scalar force value applied to the nodes parallel
   to axis three of the reference node. This is the force
   which is applied to the non-reference node, the opposite
   force is applied to the reference node.
   


reldisp
"""""""

.. code-block:: none

   relative displacement of the non-reference node
   relative to the reference node in a direction parallel to
   axis three of the reference node
   


relvel
""""""

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   relative angular velocity of the non-reference node
   relative to the reference node in a direction parallel to
   axis three of the reference node