a websitee

# Notebook Entry

• [x] Motek training, Day One
• [x] Work on parsing the walking data
• [] Make generic settings on the lab website
• [] Work on the website theme
• [] Fix the budgeting and purchasing issues
• [] Review the TODO items on the Yeadon paper
• [] Run variations in guesses for structural id
• [] Work on BMD papers

## Motek Training

The Lua scripting environment.

D-Flow Feature Requests

• feature request: output mox files to hdf5 instead
• support python alongside of lua because of the abundance of scientific code
• allow scripting outside the d-flow loop, ie.e start stop the loop, init code outside of it
• include the Lua interpreter in the script module window for interactive debugging
• Allow Lua scripts to be run and debugged outside of D-Flow
• Introduce extensive keyboard shortcuts for interacting with modules.

Bugs

• Any top layer D-Flow related window does not gt hidden when you select windows that are behind it.

## Walking System Identification

Ton's idea is to identify both the phase dependent gain matrix and the "commanded" gait cycle. I didn't understand the idea about identifying the commanded gait cycle (angles and rates) and still don't know if I understand what it means conceptually. But I think the problem now becomes non-linear.

$m(t) = K(t) [s_{lc}(t) - s(t)]$

If we measure $$m(t)$$ and $$s(t)$$ and want to solve for $$K(t)$$ and $$s_{lc}(t)$$ then things look non-linear:

$m(t) = K(t) s_{lc}(t) - K(t)s(t)$

But Ton was writing it like:

$m(t) = A(t) - K(t)s(t)$

If we have:

• $$n$$ time samples in a cycle
• $$m$$ cycles
• $$p$$ sensors
• $$q$$ controls

Then for one cycle:

• $$K$$: $$q \times p$$
• $$s$$: $$p \times 1$$
• $$s_{lc}$$: $$p \times 1$$
• $$m$$: $$q x 1$$

$$A$$ is then shape $$q \times 1$$ so we could solve for the entries of $$A$$ and not for $$s_{lc}$$ explicitly. Then at each time step in a cycle we have $$q + qp$$ unknowns giving $$nq(1 + p)$$ unknowns for a cycle and thus need that many equations. Each cycle gives us $$nq$$ equations so we need at least $$1 + p$$ cycles to solve for the entries of $$A$$ and $$K$$.