How to use Kontrol

Kontrol was designed to help setting up a KAGRA vibration isolation system. But, because many control systems in gravitational-wave detectors are set up in a similar way, Kontrol can help setting up other control systems as well. You should have Kontrol installed. If you haven’t, refer to Getting Started.

Kontrol provides the necessary modules and functionality for setting a control system.

  1. Sensors and actuators calibration and alignment (kontrol.sensact).

    1. kontrol.sensact.calibrate() for calibrating linear sensors.

    2. kontrol.curvefit.TransferFunctionFit for calibrated inertial sensors (sensors with frequency responses.)

    3. kontrol.sensact.SensingMatrix for refining sensing matrices for aligning signals.

  2. System modeling (kontrol.curvefit).

    1. kontrol.curvefit.TransferFunctionFit for modeling system processes.

    2. kontrol.curvefit.spectrum_fit() for modeling frequency spectrums with the magnitude response of a transfer function.

  3. Controller design (kontrol.regulator).

    1. kontrol.regulator.oscillator.pid() for designing position and damping PID controllers for oscillatory systems (systems with complex poles) with coefficients determined by critical criteria.

    2. kontrol.regulator.post_filter for designing post lower-pass and notch filters with stability constrains.

Kontrol also provides advanced features for optimizing seismic isolation systems.

  1. H-infinity optimization for solving complementary filter problems (kontrol.ComplementaryFilter).

    1. Optimizes complementary filters for sensor fusion.

    2. Optimizes sensor correction filters for sensor correction.

    3. Optimizes feedback controller with known disturbance and noise.

All aforementioned funtionalities are detailed in Chapter 6 and 8 in Ref. 1. These methods solve the static optimal control problem for a seismic isolation system. And, you can find example usages of them in the Tutorials.

References

1

Terrence Tak Lun Tsang. Optimizing Active Vibration Isolation Systems in Ground-Based Interferometric Gravitational-Wave Detectors. https://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/DocDB/ShowDocument?docid=14296