Humanoid Locomotion

Controller

An Efficiently Solvable Quadratic Program for Stabilizing Dynamic Locomotion (Scott Kuindersma, Frank Permenter, and Russ Tedrake)

Roughly equivalent to InstantaneousQPController

Disturbance Rejection

Rejects random forces applied to upper torso at random directions and positions with magnitude 120N for 0.1s

1. Run python3 HumanoidController.py
   • Formulate-Solve Time: 0.04s
   • 20s of simulation takes around 20mins to run

Trajectory tracking

TODO

Planner

Whole-body Motion Planning with Centroidal Dynamics and Full Kinematics (Hongkai Dai, Andrés Valenzuela and Russ Tedrake)

Adapted from http://underactuated.mit.edu/humanoids.html#example1

Simple walking

Simple forward walking trajectory with hard-coded contact schedule and periodicity

python3 Planner.py

• Takes around 40mins to solve
• Not solved to optimum (some constraints may be violated / may not be physically feasible)

  SNOPTA EXIT  80 -- insufficient storage allocated
  SNOPTA INFO  83 -- not enough integer storage

• Potential fix: https://stackoverflow.com/questions/68295629/solving-error-of-snopt-in-drake-how-to-fix-it But requires compiling from source which requires SNOPT license...
  • If someone could lend me a SNOPT license, that'd be great... :pleading_face:
• Decapitated and dismembered to improve solve time...

Troubleshooting

Out of memory when building drake

In CMakeLists.txt, add --jobs 4 after ${BAZEL_TARGETS}

ExternalProject_Add(drake_cxx_python
  SOURCE_DIR "${PROJECT_SOURCE_DIR}"
  CONFIGURE_COMMAND :
  BUILD_COMMAND
    ${BAZEL_ENV}
    "${Bazel_EXECUTABLE}"
    ${BAZEL_STARTUP_ARGS}
    build
    ${BAZEL_ARGS}
    ${BAZEL_TARGETS}
    --jobs 4
  BUILD_IN_SOURCE ON
  BUILD_ALWAYS ON
  INSTALL_COMMAND
    ${BAZEL_ENV}
    "${Bazel_EXECUTABLE}"
    ${BAZEL_STARTUP_ARGS}
    run
    ${BAZEL_ARGS}
    ${BAZEL_TARGETS}
    --
    ${BAZEL_TARGETS_ARGS}
  USES_TERMINAL_BUILD ON
  USES_TERMINAL_INSTALL ON
)

Link error on std::filesystem calls

Error

error: undefined reference to 'std::filesystem::__cxx11::path::_M_find_extension() const'

Use gcc 7 instead of gcc 8

VTK problems when launching drake-visualizer

• ModuleNotFoundError: No module named 'vtkCommonCorePython'
• libvtkxxx.so: No such file or directory

In CMakeLists.txt, add --define="-DUSE_SYSTEM_VTK=OFF" after ${BAZEL_TARGETS}