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Benchmarks

To attain maximal performance, it is recommended to pass -O3, --check-bounds=no as command line flags to julia. As of Julia 1.1, maximizing performance for the dynamics! algorithm requires either setting the number of BLAS threads to 1 (using LinearAlgebra; BLAS.set_num_threads(1)) if using OpenBLAS (the default), or compiling Julia with MKL. See this issue for more information.

Run perf/runbenchmarks.jl to see benchmark results for the Atlas robot (v5). Results below are for the following scenarios:

  1. Compute the joint-space mass matrix.
  2. Compute both the mass matrix and a geometric Jacobian from the left hand to the right foot.
  3. Do inverse dynamics.
  4. Do forward dynamics.

Note that results on CI builds are not at all representative because of code coverage. Results on a reasonably fast laptop at commit 870bea6:

Output of versioninfo():

Julia Version 1.5.3
Commit 788b2c77c1 (2020-11-09 13:37 UTC)
Platform Info:
  OS: macOS (x86_64-apple-darwin18.7.0)
  CPU: Intel(R) Core(TM) i7-8850H CPU @ 2.60GHz
  WORD_SIZE: 64
  LIBM: libopenlibm
  LLVM: libLLVM-9.0.1 (ORCJIT, skylake)

Note that this is a different machine than the one that was used for earlier benchmarks.

Mass matrix:

  memory estimate:  0 bytes
  allocs estimate:  0
  --------------
  minimum time:     4.415 μs (0.00% GC)
  median time:      4.579 μs (0.00% GC)
  mean time:        4.916 μs (0.00% GC)
  maximum time:     19.794 μs (0.00% GC)

Mass matrix and Jacobian from left hand to right foot:

  memory estimate:  0 bytes
  allocs estimate:  0
  --------------
  minimum time:     4.860 μs (0.00% GC)
  median time:      4.982 μs (0.00% GC)
  mean time:        5.399 μs (0.00% GC)
  maximum time:     24.712 μs (0.00% GC)

Note the low additional cost of computing a Jacobian when the mass matrix is already computed. This is because RigidBodyDynamics.jl caches intermediate computation results.

Inverse dynamics:

  memory estimate:  0 bytes
  allocs estimate:  0
  --------------
  minimum time:     4.256 μs (0.00% GC)
  median time:      4.541 μs (0.00% GC)
  mean time:        4.831 μs (0.00% GC)
  maximum time:     21.625 μs (0.00% GC)

Forward dynamics:

  memory estimate:  0 bytes
  allocs estimate:  0
  --------------
  minimum time:     13.600 μs (0.00% GC)
  median time:      14.419 μs (0.00% GC)
  mean time:        16.071 μs (0.00% GC)
  maximum time:     55.328 μs (0.00% GC)