Mechanism type in RigidBodyDynamics.jl defaulting to Mechanism type in ConstrainedDynamics.jl

General Usage
1

I’m new to the RigidBodyDynamics package and wanted to follow this tutorial.

Quickstart - double pendulum

When I call the Mechanism type I get errors. Here is my code along with the errors. It appears based on the error that it is expecting a type defined by the “mechaism_struct” in the ConstrainedDynamics.jl package, and thus is expecting additional parameters to be defined (bodes, delta t).

using RigidBodyDynamics

using StaticArrays

using LinearAlgebra

g = -9.81 # gravitational acceleration in z-direction

world = RigidBody{Float64}("world")

doublependulum = Mechanism(world; gravity = SVector(0, 0, g))

ERROR: MethodError: no method matching Mechanism(::RigidBody{Float64}; gravity=[0.0, 0.0, -9.81])
Closest candidates are:
  Mechanism(::Origin{T}, ::Array{Body{T}, 1}; Δt, g) where T at C:\Users\JuliaProctor\.julia\packages\ConstrainedDynamics\yq8xZ\src\main_components\mechanism_struct.jl:146 got unsupported keyword argument "gravity"
  Mechanism(::Origin{T}, ::Array{Body{T}, 1}, ::Vector{<:EqualityConstraint{T}}; Δt, g) where T at C:\Users\JuliaProctor\.julia\packages\ConstrainedDynamics\yq8xZ\src\main_components\mechanism_struct.jl:127 got unsupported keyword argument "gravity"  Mechanism(::Origin{T}, ::Array{Body{T}, 1}, ::Vector{<:EqualityConstraint{T}}, ::Vector{<:InequalityConstraint{T}}; Δt, g) where T at C:\Users\JuliaProctor\.julia\packages\ConstrainedDynamics\yq8xZ\src\main_components\mechanism_struct.jl:39 got unsupported keyword argument "gravity"

How is this happening if I’m not even using the ConstrainedDynamics package in this script? Any ideas to resolve this issue are much appreciated.

2

Works fine here, perhaps you have an old version of something?

julia> doublependulum = Mechanism(world; gravity = SVector(0, 0, g))
Spanning tree:
Vertex: world (root)
No non-tree joints.

(jl_UkHAQX) pkg> st
      Status `/tmp/jl_UkHAQX/Project.toml`
  [366cf18f] RigidBodyDynamics v2.3.2
  [90137ffa] StaticArrays v1.4.6