FixTheRobot Explore Robotics / Guidance, Navigation and Control / M10 / M10-L1

This lab works on phones, but writing code is much easier on a laptop.

Guidance, Navigation and Control · Aircraft GNC · M10-L1 · Intermediate

Name the Mode

Bench log · Hopper on the test range

10:30. The survey aircraft was flown with elevator and rudder doublets for the first time and the data engineer has four plots and no labels. The test pilot says the nose "bounces" after a pull and the tail "wags" after a rudder kick.

You will name what each record shows, extract frequency and damping from a free response, and work out how much pitch stiffness the nose bounce needs.

Your task

    Simulation
    solution.pyLoading Python…
    Ctrl+Enter runs
    What Python can I use?

    Plain Python 3 with the standard library and the course library gnckit (import gnckit as g: transfer functions and margins, state space and LQR, the Hopper model, quaternions, a convex solver). NumPy is not available in the browser. Your code runs in a background worker: an endless loop is stopped after a few seconds and the page stays usable. It runs in your browser and is never sent anywhere.

    Hints

    What this lab teaches

    Stage 1: reading a mode from a record by its period, decay and time scale: short period, phugoid, Dutch roll, roll subsidence. Stage 2: the logarithmic decrement and the difference between the damped and the natural frequency. Stage 3: the short-period frequency as ω² = Zw Mq − U0 Mw, and the stability derivative that changes it.

    Grading checks your names, compares your frequency and damping with the true ones (3% and 5%) on hidden records, and your derivative with the formula to 1e-9.

    Theory for this lab

    Aircraft GNC labs

    1. M10-L1: Name the Mode: this lab.
    2. M10-L2: Close the Loops in Order

    Educational simplification: an illustrative airframe in stability axes with round numbers, linear responses and clean records without noise or turbulence; module 10 treats the full derivation of the modes and their approximations.

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