Merge pull request #260 from sathvikbhagavan/sb/accelerometer

feat(Translational): add AccelerationSensor

Author: ChrisRackauckas

src/Mechanical/Translational/Translational.jl

@@ -21,7 +21,7 @@ include("components.jl")
 export Force, Position, Velocity, Acceleration
 include("sources.jl")
 
-export ForceSensor, PositionSensor
+export ForceSensor, PositionSensor, AccelerationSensor
 include("sensors.jl")
 
 end

src/Mechanical/Translational/sensors.jl

@@ -5,8 +5,8 @@ Linear 1D force input sensor.
 
 # Connectors:
 
-  - `flange`: 1-dim. translational flange
-  - `output`: real output
+- `flange`: 1-dim. translational flange
+- `output`: real output
 """
 @mtkmodel ForceSensor begin
     @components begin
@@ -30,8 +30,8 @@ Linear 1D position input sensor.
 
 # Connectors:
 
-  - `flange`: 1-dim. translational flange
-  - `output`: real output
+- `flange`: 1-dim. translational flange
+- `output`: real output
 """
 @mtkmodel PositionSensor begin
     @components begin
@@ -49,3 +49,34 @@ Linear 1D position input sensor.
         flange.f ~ 0.0
     end
 end
+
+"""
+    AccelerationSensor(; name)
+
+Linear 1D position input sensor.
+
+# States:
+
+- `a`: [m/s^2] measured acceleration
+
+# Connectors:
+
+- `flange`: 1-dim. translational flange
+- `output`: real output
+"""
+@mtkmodel AccelerationSensor begin
+    @components begin
+        flange = MechanicalPort()
+        output = RealOutput()
+    end
+
+    @variables begin
+        a(t) = 0.0
+    end
+
+    @equations begin
+        a ~ D(flange.v)
+        output.u ~ a
+        flange.f ~ 0.0
+    end
+end

test/Mechanical/translational.jl

@@ -153,4 +153,24 @@ end
     s_b = 2 - delta_s + 1
 
     @test sol[s.pos_value.u][end]≈s_b atol=1e-3
+
+    @testset "AccelerationSensor" begin
+        @named acc = TV.AccelerationSensor()
+        m = 4
+        @named mass = TV.Mass(m = m)
+        @named force = TV.Force()
+        @named source = Sine(frequency = 2, amplitude = 1)
+        @named acc_output = RealOutput()
+        eqs = [
+            connect(force.f, source.output),
+            connect(force.flange, mass.flange),
+            connect(acc.flange, mass.flange),
+            connect(acc_output, acc.output)
+        ]
+        @named sys = ODESystem(eqs, t, [], []; systems = [force, source, mass, acc, acc_output])
+        s = complete(structural_simplify(sys))
+        prob = ODEProblem(s, [], (0.0, pi))
+        sol = solve(prob, Tsit5())
+        @test sol[sys.acc_output.u] ≈ (sol[sys.mass.f] ./ m)
+    end
 end