Add AbsolutePoision sensor to AbsoluteAccCentrifugal test

Author: AbdulrhmnGhanem

src/Mechanical/PlanarMechanics/components.jl

@@ -123,11 +123,11 @@ A fixed translation between two components (rigid rod)
     @extend frame_a, frame_b = partial_frames = PartialTwoFrames()
 
     @parameters begin
-        rx,
+        rx = 0,
         [
             description = "Fixed x-length of the rod resolved w.r.t to body frame_a at phi = 0",
         ]
-        ry,
+        ry = 0,
         [
             description = "Fixed y-length of the rod resolved w.r.t to body frame_a at phi = 0",
         ]

src/Mechanical/PlanarMechanics/joints.jl

@@ -21,22 +21,28 @@ A revolute joint
   - `support` [Support](@ref) if `use_flange == true`
 
 """
-@component function Revolute(; name, phi = 0.0, ω = 0.0, tau = 0.0, use_flange = false)
+@component function Revolute(;
+    name,
+    constant_phi = nothing,
+    constant_ω = nothing,
+    constat_tau = nothing,
+    use_flange = false)
     @named partial_frames = PartialTwoFrames()
     @unpack frame_a, frame_b = partial_frames
     @named fixed = Rotational.Fixed()
     systems = [frame_a, frame_b, fixed]
 
     vars = @variables begin
-        phi(t) = phi
-        ω(t) = ω
+        phi(t) = 0.0
+        ω(t) = 0.0
         α(t) = 0.0
-        j(t) = tau
+        j(t) = 0.0
     end
 
     eqs = [
-        ω ~ D(phi),
-        α ~ D(ω),
+        phi ~ ifelse(constant_phi === nothing, phi, constant_phi),
+        ω ~ ifelse(constant_ω === nothing, D(phi), constant_ω),
+        α ~ ifelse(constant_ω === nothing, D(ω), 0.0),
         # rigidly connect positions
         frame_a.x ~ frame_b.x,
         frame_a.y ~ frame_b.y,
@@ -46,6 +52,7 @@ A revolute joint
         frame_a.fy + frame_b.fy ~ 0,
         # balance torques
         frame_a.j + frame_b.j ~ 0,
+        j ~ ifelse(constat_tau === nothing, j, constat_tau),
         frame_a.j ~ j,
     ]
 

test/Mechanical/planar_mechanics.jl

@@ -34,7 +34,7 @@ end
     @named ceiling = Fixed()
     @named rod = FixedTranslation(rx = 1.0, ry = 0.0)
     @named body = Body(m = 1, j = 0.1)
-    @named revolute = Revolute(phi = 0.0, ω = 0.0)
+    @named revolute = Revolute()
 
     connections = [
         connect(ceiling.frame, revolute.frame_a),
@@ -65,18 +65,25 @@ end
     m = 1
     j = 0.1
     ω = 10
-    resolve_in_frame = :world
 
     # components
     @named body = Body(; m, j, gy = 0.0)
     @named fixed_translation = FixedTranslation(; rx = 10.0, ry = 0.0)
     @named fixed = Fixed()
-    @named revolute = Revolute(ω = ω)
+    @named revolute = Revolute(constant_ω = ω)
+
+    # sensors
+    @named abs_pos_sensor = AbsolutePosition()
 
     eqs = [
-        connect(fixed_translation.frame_b, body.frame),
         connect(fixed.frame, revolute.frame_a),
         connect(revolute.frame_b, fixed_translation.frame_a),
+        connect(fixed_translation.frame_b, body.frame),
+        connect(abs_pos_sensor.frame_a, body.frame),
+        # TODO: the following equations shouldn't be necessary
+        body.ω ~ revolute.ω,
+        fixed.frame.fy ~ -body.fy,
+        fixed.frame.fx ~ -body.fx,
     ]
 
     @named model = ODESystem(eqs,
@@ -88,9 +95,10 @@ end
             fixed_translation,
             fixed,
             revolute,
+            abs_pos_sensor,
         ])
     sys = structural_simplify(model)
-    prob = ODEProblem(sys, [0.0, 10.0, 0.0], tspan, []; jac = true)
+    prob = ODEProblem(sys, [0.0], tspan, []; jac = true)
     sol = solve(prob, Rodas5P())
 
     # phi