MarkerNodeODE1Coordinate

A node-Marker attached to a ODE1 coordinate of a node.

Interface

Provides: Coordinate
Connectors, constraints and loads that can use it: ObjectConnectorCoordinateSpringDamper, ObjectConnectorCoordinateSpringDamperExt, ObjectConnectorCoordinate, ObjectContactCoordinate, LoadCoordinate

Parameters

The parameters of the item; in a dictionary, its type is ‘NodeODE1Coordinate’:

name	type	default	description
name	String	‘’	marker’s unique name
nodeNumber	NodeIndex	invalid (-1)	node number to which marker is attached to
coordinate	UInt	invalid (-1)	coordinate of node to which marker is attached to; must be given: the default is only a placeholder
visualization	VMarkerNodeODE1Coordinate		parameters for visualization of item

Visualization parameters

VMarkerNodeODE1Coordinate has no parameters.

Drawing

The item draws nothing.

Detailed description

Marker quantities

quantity	symbol	as computed
coordinate	\(c = y_i\)	the current ODE1 coordinate `coordinate` \(= i\) of the node

There is no velocity: an ODE1 coordinate has no time derivative of its own in the solver.

Jacobians

\(\Jm = \ev_i\tp\), a row of the unit matrix. On a node without ODE1 coordinates the value is zero and the Jacobian empty.

Mini example

#a coordinate of a first-order system: a constant input to q_t = -q + f
node = mbs.AddNode(NodeGenericODE1(numberOfODE1Coordinates=1, referenceCoordinates=[0],
                                   initialCoordinates=[0]))
mbs.AddObject(ObjectGenericODE1(nodeNumbers=[node], systemMatrix=[[-1]]))
mCoord = mbs.AddMarker(MarkerNodeODE1Coordinate(nodeNumber=node, coordinate=0))
mbs.AddLoad(LoadCoordinate(markerNumber=mCoord, load=1))

mbs.Assemble()
mbs.SolveDynamic(solverType=exu.DynamicSolverType.RK44)

#q(1) = 1 - exp(-1)
exu.sys['testResult'] = mbs.GetNodeOutput(node, exu.OutputVariableType.Coordinates) #0.632