lowdrant / secretbandname

Planar biped control and simulation project for ECE4560

secretbandname

Bipedal Robot lab project for ECE4560 | Fall 2017

Data

Link Lengths

Motors

Angle Measurement

Angles relative to each frame are measured from the negative y-axis. Exactly like this pendulum's angle.

Internal Data Management

Rough Sketch of Setup

• Link lengths are stored as an Nx1 vector

  • Both biped legs are identical in geometry
  • Link indices follow this diagram
  • Lengths are in millimeters

• Joint angles are stored as an Nx2 matrix

  • The biped legs can be configured independently
  • 1st column corresponds with the left leg
  • 2nd column corresponds with the right leg
  • Angles are in radians

• Link COM and Motor COM data are input separately

  • Link and Motor COMs don't correspond intuitively
  • Need to perfom link-specific motor centroid translations
  • Handling calculations internally removes them from the input
  • Link COM data included for forward-compatibility

• One full gait trajectory is stored in gaitData.mat

  • Moving right foot data is stored in swingRight.mat
  • Recentering right foot data is stored in doubleRL.mat
  • The left foot trajectory is reated by mirroring right foot trajectories

Stability

See this document.

Zero-Configuration

All joints in a vertical line, with their y-axes parallel to that line.

Notes

• L₃ & L₄ extend along the Foot Frame x-axis
• update_linkframes is called every time the joint angles change
• L₀ was calulated by doubling the plastic connector's length
• Link length measurements include motors' contributions
• For lab scripts, got to labs/
• Be sure to clone the Optragen submodule for trajectory generation

Authors

• Madeleyne Vaca
• Marion Anderson

References

• Biped Class Wiki

Special Thanks

• Alex Chang - ECE4560 TA
• Patricio Vela - ECE4560 Professor

License

It should be noted that not all the work here is mine. In particular, this project was a class assignment, and I had no involvement whatsoever in the development of Optragen.

However, the MATLAB code in this repository, beyond skeleton code for the SE2 and Biped classes, was developed by Madeleyne and me.

We have no issue with that code being used for inspiration, knowledge gap-filling, or utility, but it is the result of academic coursework. Deliberate duplication with intent to substitue understanding in an academic setting would constitute plagiarism.