add some joint assemblies

MWE

updates

Author: baggepinnen

src/Multibody.jl

@@ -1,7 +1,8 @@
 # Find variables that are both array form and scalarized / collected
 # foreach(println, sort(unknowns(IRSystem(model)), by=string))
 module Multibody
-
+# Find variables that are both array form and scalarized / collected
+# foreach(println, sort(unknowns(IRSystem(model)), by=string))
 using LinearAlgebra
 using ModelingToolkit
 using JuliaSimCompiler
@@ -208,6 +209,4 @@ include("robot/path_planning.jl")
 include("robot/robot_components.jl")
 include("robot/FullRobot.jl")
 
-
-
 end

src/components.jl

@@ -124,7 +124,7 @@ Can be thought of as a massless rod. For a massive rod, see [`BodyShape`](@ref)
 @component function FixedTranslation(; name, r, radius=0.02f0, color = purple, render = true)
     @named frame_a = Frame()
     @named frame_b = Frame()
-    @parameters r[1:3]=r [
+    @parameters r[1:3]=collect(r) [
         description = "position vector from frame_a to frame_b, resolved in frame_a",
     ]
     r = collect(r)