switch torque variable to tau for consistency

Author: baggepinnen

src/PlanarMechanics/PlanarMechanics.jl

@@ -6,13 +6,14 @@ module PlanarMechanics
 
 import ModelingToolkitStandardLibrary.Mechanical.Rotational
 import ModelingToolkitStandardLibrary.Mechanical.TranslationalModelica
+import ModelingToolkitStandardLibrary.Blocks
 using ModelingToolkit: t_nounits as t, D_nounits as D
 using ModelingToolkit
 using ...Blocks: RealInput, RealOutput
 import ...@symcheck
 import ..Multibody
 
-export Frame, FrameResolve, PartialTwoFrames, ZeroPosition
+export Frame, FrameResolve, PartialTwoFrames, ZeroPosition, ori_2d
 include("utils.jl")
 
 export Fixed, Body, FixedTranslation, Spring, Damper, SpringDamper

src/PlanarMechanics/components.jl

@@ -40,7 +40,7 @@ Body component with mass and inertia
 
 # Parameters:
 - `m`: [kg] mass of the body
-- `j`: [kg.m²] inertia of the body with respect to the origin of `frame` along the z-axis of `frame`
+- `I`: [kg.m²] inertia of the body with respect to the origin of `frame` along the z-axis of `frame`
 - `r`: [m, m] Translational position x,y-position
 - `gy`: [m/s²] gravity field acting on the mass in the y-direction, positive value acts in the positive direction defaults to -9.807
 - `radius`: [m] Radius of the body in animations
@@ -71,13 +71,13 @@ Body component with mass and inertia
     end
 
     vars = @variables begin
-        f(t)[1:2]
-        r(t)[1:2] = r
-        v(t)[1:2]
-        a(t)[1:2]
-        phi(t) = phi
-        ω(t)
-        α(t)
+        f(t)[1:2], [description = "Force"]
+        (r(t)[1:2] = r), [description = "x,y position"]
+        v(t)[1:2], [description = "x,y velocity"]
+        a(t)[1:2], [description = "x,y acceleration"]
+        (phi(t) = phi), [description = "Rotation angle"]
+        ω(t), [description = "Angular velocity"]
+        α(t), [description = "Angular acceleration"]
     end
 
     eqs = [
@@ -92,7 +92,7 @@ Body component with mass and inertia
         # newton's law
         f .~ [frame.fx, frame.fy]
         f + [0, m*gy] .~ m*a#ifelse(gy !== nothing, fy / m + gy, fy / m),
-        I * α ~ frame.j
+        I * α ~ frame.tau
     ]
 
     return compose(ODESystem(eqs, t, vars, pars; name),
@@ -183,7 +183,7 @@ A fixed translation between two components (rigid rod)
         # balancing force including lever principle
         frame_a.fx + frame_b.fx ~ 0
         frame_a.fy + frame_b.fy ~ 0
-        frame_a.j + frame_b.j + r0' * [frame_b.fy, -frame_b.fx] ~ 0
+        frame_a.tau + frame_b.tau + r0' * [frame_b.fy, -frame_b.fx] ~ 0
     end
 end
 
@@ -248,8 +248,8 @@ Linear 2D translational spring
 
     @equations begin
         phi_rel ~ frame_b.phi - frame_a.phi
-        frame_a.j ~ 0
-        frame_b.j ~ 0
+        frame_a.tau ~ 0
+        frame_b.tau ~ 0
         s_relx ~ frame_b.x - frame_a.x
         s_rely ~ frame_b.y - frame_a.y
         f_x ~ c_x * (s_relx - s_relx0)
@@ -313,10 +313,10 @@ Linear (velocity dependent) damper
         d0y ~ ifelse(l < s_small, r0[2], r0[2] / l)
         frame_a.fx ~ d0x * f
         frame_a.fy ~ d0y * f
-        frame_a.j ~ 0
+        frame_a.tau ~ 0
         frame_a.fx + frame_b.fx ~ 0
         frame_a.fy + frame_b.fy ~ 0
-        frame_a.j + frame_b.j ~ 0
+        frame_a.tau + frame_b.tau ~ 0
 
         # lossPower ~ -f * v
     end
@@ -382,7 +382,7 @@ Linear 2D translational spring damper model
         phi_rel(t) = 0
         f_x(t)
         f_y(t)
-        j(t)
+        tau(t)
     end
 
     begin
@@ -399,9 +399,9 @@ Linear 2D translational spring damper model
         v_rely ~ D(s_rely)
         ω_rel ~ D(phi_rel)
 
-        j ~ c_phi * (phi_rel - phi_rel0) + d_phi * ω_rel
-        frame_a.j ~ -j
-        frame_b.j ~ j
+        tau ~ c_phi * (phi_rel - phi_rel0) + d_phi * ω_rel
+        frame_a.tau ~ -tau
+        frame_b.tau ~ tau
         f_x ~ c_x * (s_relx - s_relx0) + d_x * v_relx
         f_y ~ c_y * (s_rely - s_rely0) + d_y * v_rely
         frame_a.fx ~ -f_x

src/PlanarMechanics/joints.jl

@@ -33,7 +33,7 @@ https://github.com/dzimmer/PlanarMechanics/blob/743462f58858a808202be93b70839146
         (phi(t) = 0.0), [state_priority=10]
         (ω(t) = 0.0), [state_priority=10]
         α(t)
-        j(t)
+        tau(t)
     end
 
     pars = @parameters begin
@@ -53,8 +53,8 @@ https://github.com/dzimmer/PlanarMechanics/blob/743462f58858a808202be93b70839146
         frame_a.fx + frame_b.fx ~ 0,
         frame_a.fy + frame_b.fy ~ 0,
         # balance torques
-        frame_a.j + frame_b.j ~ 0,
-        frame_a.j ~ j
+        frame_a.tau + frame_b.tau ~ 0,
+        frame_a.tau ~ tau
     ]
 
     if use_flange
@@ -67,7 +67,7 @@ https://github.com/dzimmer/PlanarMechanics/blob/743462f58858a808202be93b70839146
         push!(eqs, connect(fixed.flange, support))
     else
         # actutation torque
-        push!(eqs, j ~ 0)
+        push!(eqs, tau ~ 0)
     end
 
 
@@ -143,7 +143,7 @@ https://github.com/dzimmer/PlanarMechanics/blob/743462f58858a808202be93b70839146
         frame_a.phi ~ frame_b.phi,
         frame_a.fx + frame_b.fx ~ 0,
         frame_a.fy + frame_b.fy ~ 0,
-        frame_a.j + frame_b.j + r0[1] * frame_b.fy - r0[2] * frame_b.fx ~ 0,
+        frame_a.tau + frame_b.tau + r0[1] * frame_b.fy - r0[2] * frame_b.fx ~ 0,
         e0[1] * frame_a.fx + e0[2] * frame_a.fy ~ f
     ]
 

src/PlanarMechanics/sensors.jl

@@ -50,10 +50,10 @@ Partial absolute sensor models for sensors defined by equations (frame_resolve m
         # https://github.com/dzimmer/PlanarMechanics/blob/443b007bcc1522bb172f13012e2d7a8ecc3f7a9b/PlanarMechanics/Sensors/Internal/PartialAbsoluteBaseSensor.mo#L20-L21
         frame_a.fx ~ 0
         frame_a.fy ~ 0
-        frame_a.j ~ 0
+        frame_a.tau ~ 0
         frame_resolve.fx ~ 0
         frame_resolve.fy ~ 0
-        frame_resolve.j ~ 0
+        frame_resolve.tau ~ 0
     end
 end
 
@@ -79,13 +79,13 @@ Partial relative sensor models for sensors defined by equations (frame_resolve m
 
         frame_a.fx ~ 0
         frame_a.fy ~ 0
-        frame_a.j ~ 0
+        frame_a.tau ~ 0
         frame_b.fx ~ 0
         frame_b.fy ~ 0
-        frame_b.j ~ 0
+        frame_b.tau ~ 0
         frame_resolve.fx ~ 0
         frame_resolve.fy ~ 0
-        frame_resolve.j ~ 0
+        frame_resolve.tau ~ 0
     end
 end
 
@@ -140,7 +140,7 @@ Measure absolute position and orientation (same as Sensors.AbsolutePosition, but
         phi.u ~ r[3],
         frame_a.fx ~ 0,
         frame_a.fy ~ 0,
-        frame_a.j ~ 0
+        frame_a.tau ~ 0
     ]
 
     return compose(ODESystem(eqs, t, [], []; name = name),
@@ -249,10 +249,10 @@ Measure relative position and orientation between the origins of two frame conne
         rel_phi.u ~ r[3],
         frame_a.fx ~ 0,
         frame_a.fy ~ 0,
-        frame_a.j ~ 0,
+        frame_a.tau ~ 0,
         frame_b.fx ~ 0,
         frame_b.fy ~ 0,
-        frame_b.j ~ 0
+        frame_b.tau ~ 0
     ]
 
     return compose(ODESystem(eqs, t, [], []; name = name),
@@ -330,10 +330,10 @@ end
         # https://github.com/dzimmer/PlanarMechanics/blob/443b007bcc1522bb172f13012e2d7a8ecc3f7a9b/PlanarMechanics/Sensors/Internal/BasicTransformAbsoluteVector.mo#L42-L43
         frame_a.fx ~ 0,
         frame_a.fy ~ 0,
-        frame_a.j ~ 0,
+        frame_a.tau ~ 0,
         frame_resolve.fx ~ 0,
         frame_resolve.fy ~ 0,
-        frame_resolve.j ~ 0
+        frame_resolve.tau ~ 0
     ]
 
     r_temp = Vector{Float64}(undef, 3)

src/PlanarMechanics/utils.jl

@@ -4,7 +4,7 @@
     phi(t), [state_priority=2, description = "rotation angle (counterclockwise)"]
     fx(t), [connect = Flow, description = "force in the x direction"]
     fy(t), [connect = Flow, description = "force in the y direction"]
-    j(t), [connect = Flow, description = "torque (clockwise)"]
+    tau(t), [connect = Flow, description = "torque (clockwise)"]
 end
 Base.@doc """
     Frame(;name)
@@ -17,9 +17,14 @@ Coordinate system (2-dim.) fixed to the component with one cut-force and cut-tor
     - `phi`: [rad] rotation angle (counterclockwise)
     - `fx`: [N] force in the x direction
     - `fy`: [N] force in the y direction
-    - `j`: [N.m] torque (clockwise)
+    - `tau`: [N.m] torque (clockwise)
 """ Frame
 
+function ori_2d(frame)
+    phi = frame.phi
+    return [cos(phi) -sin(phi); sin(phi) cos(phi)]
+end
+
 # extends Frame with just styling
 # https://github.com/dzimmer/PlanarMechanics/blob/master/PlanarMechanics/Interfaces/Frame_resolve.mo
 FrameResolve = Frame

test/test_PlanarMechanics.jl

@@ -2,6 +2,7 @@
 # using Plots
 using ModelingToolkit, OrdinaryDiffEq, Test
 using ModelingToolkit: t_nounits as t, D_nounits as D
+import ModelingToolkitStandardLibrary.Blocks
 import Multibody.PlanarMechanics as Pl
 using JuliaSimCompiler