Virtual current

Virtual sea current field.

Collaboration diagram for Virtual current:

Author

Joakim Haugen

VirtualCurrent is a manipulable current field. Error signals are used to change the magnitude and direction of the current at various depths. The adaptation is using a PID controller with integral saturation for each error signal. The sim object

Warning

This somObject does not work as expected.

Example configuration excerpt

 <Lib
   LibName                = "fhsim_base"
   SimObject              = "Adaptive/Current"
   Name                   = "C"
   ProportionalGain       = "1"
   IntegralGain           = "0"
   IntegralSaturation     = "1"
   DerivativeGain         = "0"
   DerivativeTimeConstant = "10"
   DepthLayerThickness    = "5.0, 10.0, 15.0"
 />
...
 <Connection
    C.PlanarError_L1 = "0,0"
    C.PlanarError_L2 = "0,0"
    C.PlanarError_L3 = "0,0"
 />

Input ports

Name	Width	Description
PlanarError_L1 .. PlanarError_L<N>	2	Error signal to use in adaptation. One for each depth layer; in total N.

Output ports

Name	Width	Description
PlanarCurrent_L1 .. PlanarCurrent_L<N>	2	Estimated current at specified DepthLayersThicknesses.

Configuration parameters

Name	Width	Description
ProportionalGain	1	\(P_p (p_d - p_e)\).
IntegralGain	1	\(P_i\int_0^t (p_d - p_e)\).
IntegralSaturation	1	\(\text{abs}(\max(\int_0^t (p_d - p_e))) = sat\).
DerivativeGain	1	\(P_d (\dot{e})\).
DerivativeTimeConstant	1	Time contant of the dynamics of error derivative.
DepthLayerThickness	N	Array of depths at which the virtual inputs will manipulate the current. Between these points a linear interpolation is used (and below/above boundary depths: the closest one).
MaximumCurrent	1	Upper limit on the magnitude of each component of every Current_L\<i\> state (Default: -1.0). When positive, each component is clamped to [-MaximumCurrent, MaximumCurrent] before every ODE evaluation; a non-positive value disables the limit.

Initial conditions

Name	Width	Description
Current_L1 .. Current_L<N>	2	Initial planar current at each depth layer.
IntegralError_L1 .. IntegralError_L<N>	2	Initial integral error (default: 0,0)
ErrorDerivative_L1 .. ErrorDerivative_L<N>	2	Initial derivative error (default: 0,0)

Full example file

This SimObject is referred to as Adaptive/VirtualCurrent