LIBRARY

Sources.InverseSpeedDependentTorque

Torque reciprocal dependent on speed.

Model of inverse speed dependent torque. Parameter TorqueDirection chooses whether direction of torque is the same in both directions of rotation or not. If TorqueDirection = false, regularization near zero speed avoids numerical problems.

This component extends from RotationalComponents.Interfaces.PartialTorque

Usage

RotationalComponents.Sources.InverseSpeedDependentTorque(tau_nominal, w_nominal, w0=0.1)

Parameters:

Name	Description	Units	Default value
TorqueDirection	Same direction of torque in both directions of rotation	–	true
tau_nominal	Nominal torque (if negative, torque is acting as load in positive direction of rotation)	N.m
w_nominal	Nominal speed	rad/s
w0	Regularization below w0	rad/s	0.1

Connectors

• spline - This connector represents a rotational spline with angle and torque as the potential and flow variables, respectively. (Spline)

• support - This connector represents a rotational spline with angle and torque as the potential and flow variables, respectively. (Spline)

Variables

Name	Description	Units
phi_support	Absolute angle of the support spline	rad
phi	Angle of spline with respect to support	–
w	Angular velocity of spline with respect to support (= der(phi))	rad/s
tau	Accelerating torque acting at spline (= -spline.tau)	N.m

Behavior

using RotationalComponents #hide
using ModelingToolkit #hide
@variables tau_nominal #hide
@variables w_nominal #hide
@variables w0 #hide
@named sys = RotationalComponents.Sources.InverseSpeedDependentTorque(tau_nominal=tau_nominal, w_nominal=w_nominal, w0=w0) #hide
full_equations(sys) #hide

<< @example-block not executed in draft mode >>

Source

"""
Torque reciprocal dependent on speed.

Model of inverse speed dependent torque. Parameter TorqueDirection chooses
whether direction of torque is the same in both directions of rotation or not.
If TorqueDirection = false, regularization near zero speed avoids numerical
problems.
"""
component InverseSpeedDependentTorque
  extends RotationalComponents.Interfaces.PartialTorque
  "Nominal torque (if negative, torque is acting as load in positive direction of rotation)"
  parameter tau_nominal::Torque
  "Same direction of torque in both directions of rotation"
  structural parameter TorqueDirection::Boolean = true
  "Nominal speed"
  parameter w_nominal::AngularVelocity(min = eps(Float64))
  "Regularization below w0"
  parameter w0::AngularVelocity(min = eps(Float64)) = 0.1
  "Angular velocity of spline with respect to support (= der(phi))"
  variable w::AngularVelocity
  "Accelerating torque acting at spline (= -spline.tau)"
  variable tau::Torque
relations
  w = der(phi)
  tau = -spline.tau
  if TorqueDirection
    tau = ifelse(abs(w) < w0, tau_nominal * w_nominal / w0, tau_nominal * w_nominal / abs(w))
  else
    tau = ifelse(abs(w) < w0, tau_nominal * w / w0, tau_nominal * w_nominal / w)
  end
metadata {
  "Dyad": {"icons": {"default": "dyad://RotationalComponents/InverseSpeedDepTorque.svg"}}
}
end

Flattened Source

"""
Torque reciprocal dependent on speed.

Model of inverse speed dependent torque. Parameter TorqueDirection chooses
whether direction of torque is the same in both directions of rotation or not.
If TorqueDirection = false, regularization near zero speed avoids numerical
problems.
"""
component InverseSpeedDependentTorque
  "Primary rotational shaft spline connector"
  spline = Spline() {"Dyad": {"placement": {"icon": {"x1": 950, "y1": 450, "x2": 1050, "y2": 550}}}}
  "Support spline connector"
  support = Spline() {
    "Dyad": {
      "placement": {"icon": {"iconName": "support", "x1": 450, "y1": 950, "x2": 550, "y2": 1050}}
    }
  }
  "Absolute angle of the support spline"
  variable phi_support::Angle
  "Angle of spline with respect to support"
  variable phi::Real
  "Nominal torque (if negative, torque is acting as load in positive direction of rotation)"
  parameter tau_nominal::Torque
  "Same direction of torque in both directions of rotation"
  structural parameter TorqueDirection::Boolean = true
  "Nominal speed"
  parameter w_nominal::AngularVelocity(min = eps(Float64))
  "Regularization below w0"
  parameter w0::AngularVelocity(min = eps(Float64)) = 0.1
  "Angular velocity of spline with respect to support (= der(phi))"
  variable w::AngularVelocity
  "Accelerating torque acting at spline (= -spline.tau)"
  variable tau::Torque
relations
  support.phi = phi_support
  support.tau = -spline.tau
  phi = spline.phi - phi_support
  w = der(phi)
  tau = -spline.tau
  if TorqueDirection
    tau = ifelse(abs(w) < w0, tau_nominal * w_nominal / w0, tau_nominal * w_nominal / abs(w))
  else
    tau = ifelse(abs(w) < w0, tau_nominal * w / w0, tau_nominal * w_nominal / w)
  end
metadata {
  "Dyad": {"icons": {"default": "dyad://RotationalComponents/InverseSpeedDepTorque.svg"}}
}
end

Test Cases

No test cases defined.

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