• ML-derived kinematics

    David Greenberg • 01/13/2021 at 22:18 • 0 comments

    (This is as-of December 25, 2020)

    Due to the interesting structure of a universal spine joint with 2 actuated abdominal muscles, doing the trig for the inverse kinematics isn't as simple as it would be for legged robots. As a result, I ran a simulation that tried all the different servo positions. I measured the servo positions & spine angles and trained an lightgbm model to create a kinematics controller.

    This video shows a the simulated robot doing a simple serpentine gait. While there's still a lot to do, I'm excited that some of the low-level components of the project are starting to seem real.

  • Completed integrated CAD and ROS Simulation Environment

    David Greenberg • 01/13/2021 at 22:09 • 0 comments

    (This is actually as-of Dec 19, 2020)

    This shows the environment I created that uses python to combine openscad, step file importing, and joint definitions to export to a physics and motor-control simulation-ready model for Gazebo/ROS.

    It was particularly exciting because this approach actually includes full inertial models for the entire robot, doing calculations to estimate them from the component's STEP files.

    This shows a side profile of the robot at this point, highlighting all points with their orientation axis in red, and connections points to combine components (so that all calculations can be done in local frames of reference). This shows an initial design for the body segments, spine, servo motors, and wheels for the elemental. The servo models come from the vendor's step files.