Dyad

Appearance

LIBRARY
Sources.Tests.Torque2.md

Sources.Tests.Torque2 ​

Test for Torque2: two inertias driven by a torque acting between them, matching the MSL test topology.

SpeedSource (sine, f=1 Hz) → inertia_a (J=3) → Torque2 → inertia_b (J=3) ↑ sine (f=1 Hz)

inertia_b is free on its outer flange. With tau = sin(2πt), and the flow sign convention at the connection (connect sums flow to zero), inertia_b sees +tau:

  • J_b * a_b = +tau → a_b = sin(2πt)/3

  • w_b(t) = (1 - cos(2πt))/(6π)

  • At t=1.0: w_b = 0

  • phi_b(t) = t/(6π) - sin(2πt)/(12π²)

  • At t=1.0: phi_b ≈ 1/(6π) ≈ 0.05305

Usage ​

RotationalComponents.Sources.Tests.Torque2()

Behavior ​

julia
using RotationalComponents #hide
using ModelingToolkit #hide
@named sys = RotationalComponents.Sources.Tests.Torque2() #hide
full_equations(sys) #hide
<< @example-block not executed in draft mode >>

Source ​

dyad
"""
Test for Torque2: two inertias driven by a torque acting between them, matching the MSL test topology.

SpeedSource (sine, f=1 Hz) → inertia_a (J=3) → Torque2 → inertia_b (J=3)
                                                    ↑
                                              sine (f=1 Hz)

inertia_b is free on its outer flange. With tau = sin(2πt), and the flow sign
convention at the connection (connect sums flow to zero), inertia_b sees +tau:
  - J_b * a_b = +tau → a_b = sin(2πt)/3
  - w_b(t) = (1 - cos(2πt))/(6π)
  - At t=1.0: w_b = 0
  - phi_b(t) = t/(6π) - sin(2πt)/(12π²)
  - At t=1.0: phi_b ≈ 1/(6π) ≈ 0.05305
"""
test component Torque2
  "Fixed support for speed source"
  fixed = RotationalComponents.Components.Fixed()
  "Sine signal for speed reference (amplitude=1, f=1 Hz)"
  speed_sine = BlockComponents.Sources.Sine(amplitude = 1, frequency = 1)
  "Speed source prescribing inertia_a velocity (Exact mode)"
  speed = RotationalComponents.Sources.SpeedSource(ref_type = RotationalComponents.Sources.ReferenceType.Exact())
  "First inertia (J=3), speed-driven side"
  inertia_a = RotationalComponents.Components.Inertia(J = 3)
  "Torque2 under test"
  torque2 = RotationalComponents.Sources.Torque2()
  "Sine signal for torque input (amplitude=1, f=1 Hz)"
  torque_sine = BlockComponents.Sources.Sine(amplitude = 1, frequency = 1)
  "Second inertia (J=3), free side"
  inertia_b = RotationalComponents.Components.Inertia(J = 3)
relations
  initial inertia_a.phi = 0
  initial inertia_b.phi = 0
  initial inertia_b.w = 0
  connect(speed_sine.y, speed.w_ref)
  connect(speed.support, fixed.spline)
  connect(speed.spline, inertia_a.spline_a)
  connect(inertia_a.spline_b, torque2.spline_a)
  connect(torque2.spline_b, inertia_b.spline_a)
  connect(torque_sine.y, torque2.tau)
metadata {
  "Dyad": {
    "icons": {"default": "dyad://RotationalComponents/Example.svg"},
    "tests": {
      "case1": {
        "stop": 1,
        "atol": {"inertia_b.phi": 0.001, "inertia_b.w": 0.001, "inertia_a.w": 0.001},
        "expect": {
          "initial": {"inertia_a.phi": 0, "inertia_b.phi": 0, "inertia_b.w": 0},
          "final": {"inertia_b.phi": 0.05305, "inertia_b.w": 0, "inertia_a.w": 0},
          "signals": ["inertia_b.phi", "inertia_b.w", "inertia_a.w", "inertia_a.phi"]
        }
      }
    }
  }
}
end
Flattened Source
dyad
"""
Test for Torque2: two inertias driven by a torque acting between them, matching the MSL test topology.

SpeedSource (sine, f=1 Hz) → inertia_a (J=3) → Torque2 → inertia_b (J=3)
                                                    ↑
                                              sine (f=1 Hz)

inertia_b is free on its outer flange. With tau = sin(2πt), and the flow sign
convention at the connection (connect sums flow to zero), inertia_b sees +tau:
  - J_b * a_b = +tau → a_b = sin(2πt)/3
  - w_b(t) = (1 - cos(2πt))/(6π)
  - At t=1.0: w_b = 0
  - phi_b(t) = t/(6π) - sin(2πt)/(12π²)
  - At t=1.0: phi_b ≈ 1/(6π) ≈ 0.05305
"""
test component Torque2
  "Fixed support for speed source"
  fixed = RotationalComponents.Components.Fixed()
  "Sine signal for speed reference (amplitude=1, f=1 Hz)"
  speed_sine = BlockComponents.Sources.Sine(amplitude = 1, frequency = 1)
  "Speed source prescribing inertia_a velocity (Exact mode)"
  speed = RotationalComponents.Sources.SpeedSource(ref_type = RotationalComponents.Sources.ReferenceType.Exact())
  "First inertia (J=3), speed-driven side"
  inertia_a = RotationalComponents.Components.Inertia(J = 3)
  "Torque2 under test"
  torque2 = RotationalComponents.Sources.Torque2()
  "Sine signal for torque input (amplitude=1, f=1 Hz)"
  torque_sine = BlockComponents.Sources.Sine(amplitude = 1, frequency = 1)
  "Second inertia (J=3), free side"
  inertia_b = RotationalComponents.Components.Inertia(J = 3)
relations
  initial inertia_a.phi = 0
  initial inertia_b.phi = 0
  initial inertia_b.w = 0
  connect(speed_sine.y, speed.w_ref)
  connect(speed.support, fixed.spline)
  connect(speed.spline, inertia_a.spline_a)
  connect(inertia_a.spline_b, torque2.spline_a)
  connect(torque2.spline_b, inertia_b.spline_a)
  connect(torque_sine.y, torque2.tau)
metadata {
  "Dyad": {
    "icons": {"default": "dyad://RotationalComponents/Example.svg"},
    "tests": {
      "case1": {
        "stop": 1,
        "atol": {"inertia_b.phi": 0.001, "inertia_b.w": 0.001, "inertia_a.w": 0.001},
        "expect": {
          "initial": {"inertia_a.phi": 0, "inertia_b.phi": 0, "inertia_b.w": 0},
          "final": {"inertia_b.phi": 0.05305, "inertia_b.w": 0, "inertia_a.w": 0},
          "signals": ["inertia_b.phi", "inertia_b.w", "inertia_a.w", "inertia_a.phi"]
        }
      }
    }
  }
}
end


Test Cases ​

julia
using RotationalComponents
using DyadInterface: TransientAnalysis, rebuild_sol, ODEAlg
using ModelingToolkit: toggle_namespacing, get_initial_conditions, @named
using CSV, DataFrames, Plots

snapshotsdir = joinpath(dirname(dirname(pathof(RotationalComponents))), "test", "snapshots")
<< @setup-block not executed in draft mode >>

Test Case case1 ​

julia
@named model_case1 = RotationalComponents.Sources.Tests.Torque2()
model_case1 = toggle_namespacing(model_case1, false)

model_case1 = toggle_namespacing(model_case1, true)
result_case1 = TransientAnalysis(; model = model_case1, alg = ODEAlg.Auto(), start = 0e+0, stop = 1e+0, abstol=1e-6, reltol=1e-6)
sol_case1 = rebuild_sol(result_case1)
<< @setup-block not executed in draft mode >>
julia
df_case1 = DataFrame(:t => sol_case1[:t], :actual => sol_case1[model_case1.inertia_b.phi])
dfr_case1 = try CSV.read(joinpath(snapshotsdir, "RotationalComponents.Sources.Tests.Torque2_case1_sig0.ref"), DataFrame); catch e; nothing; end
plt = plot(sol_case1, idxs=[model_case1.inertia_b.phi], width=2, label="Actual value of inertia_b.phi")
if !isnothing(dfr_case1)
  scatter!(plt, dfr_case1.t, dfr_case1.expected, mc=:red, ms=3, label="Expected value of inertia_b.phi")
end
scatter!(plt, [df_case1.t[1]], [0], label="Initial Condition for `inertia_b.phi`")
scatter!(plt, [df_case1.t[end]], [0.05305], label="Final Condition for `inertia_b.phi`")
<< @setup-block not executed in draft mode >>
julia
plt
<< @example-block not executed in draft mode >>
julia
df_case1 = DataFrame(:t => sol_case1[:t], :actual => sol_case1[model_case1.inertia_b.w])
dfr_case1 = try CSV.read(joinpath(snapshotsdir, "RotationalComponents.Sources.Tests.Torque2_case1_sig1.ref"), DataFrame); catch e; nothing; end
plt = plot(sol_case1, idxs=[model_case1.inertia_b.w], width=2, label="Actual value of inertia_b.w")
if !isnothing(dfr_case1)
  scatter!(plt, dfr_case1.t, dfr_case1.expected, mc=:red, ms=3, label="Expected value of inertia_b.w")
end
scatter!(plt, [df_case1.t[1]], [0], label="Initial Condition for `inertia_b.w`")
scatter!(plt, [df_case1.t[end]], [0], label="Final Condition for `inertia_b.w`")
<< @setup-block not executed in draft mode >>
julia
plt
<< @example-block not executed in draft mode >>
julia
df_case1 = DataFrame(:t => sol_case1[:t], :actual => sol_case1[model_case1.inertia_a.w])
dfr_case1 = try CSV.read(joinpath(snapshotsdir, "RotationalComponents.Sources.Tests.Torque2_case1_sig2.ref"), DataFrame); catch e; nothing; end
plt = plot(sol_case1, idxs=[model_case1.inertia_a.w], width=2, label="Actual value of inertia_a.w")
if !isnothing(dfr_case1)
  scatter!(plt, dfr_case1.t, dfr_case1.expected, mc=:red, ms=3, label="Expected value of inertia_a.w")
end
scatter!(plt, [df_case1.t[end]], [0], label="Final Condition for `inertia_a.w`")
<< @setup-block not executed in draft mode >>
julia
plt
<< @example-block not executed in draft mode >>
julia
df_case1 = DataFrame(:t => sol_case1[:t], :actual => sol_case1[model_case1.inertia_a.phi])
dfr_case1 = try CSV.read(joinpath(snapshotsdir, "RotationalComponents.Sources.Tests.Torque2_case1_sig3.ref"), DataFrame); catch e; nothing; end
plt = plot(sol_case1, idxs=[model_case1.inertia_a.phi], width=2, label="Actual value of inertia_a.phi")
if !isnothing(dfr_case1)
  scatter!(plt, dfr_case1.t, dfr_case1.expected, mc=:red, ms=3, label="Expected value of inertia_a.phi")
end
scatter!(plt, [df_case1.t[1]], [0], label="Initial Condition for `inertia_a.phi`")
<< @setup-block not executed in draft mode >>
julia
plt
<< @example-block not executed in draft mode >>