Kontrol Home

Python package for KAGRA suspension and seismic isolation control.

Kontrol

The name “Kontrol” is a blend word combining KAGRA, the gravitational-wave detector in Japan, and control, as in control system. The package contains necessary features for commissioning a KAGRA suspension. These features include:

• Sensor and actuation utilities (kontrol.sensact): Calibration and Sensing/Actuation Matrices

• System Modeling (kontrol.curvefit): Fitting frequency response data using Transfer function model.

• Basic suspension controller design (kontrol.regulator): Damping and position controller with stabilizing post filters such as low-pass and notch filters.

To interface the results generated from the above functionalities to the KAGRA control system, Kontrol also provides:

• Foton utilities (kontrol.foton): converting transfer function to/from Foton strings.

• Ezca wrapper (kontrol.ezca): Fetch/put control matrices to/from the digital system.

The above features form a control design pipeline from calibration to controller design for commissioning KAGRA suspension with basic functionality.

Besides the basic functionalities, Kontrol also contains advanced features are being continuously developed in order to further enhance seismic isolation performance. Currently, Kontrol contains:

• H-infinity optimal complementary filters (kontrol.ComplementaryFilter): Solves complementary control problems, optimizing control filters for sensor fusion, sensor correction, and vibration isolation control problems 1 2.

• Dynamic mode decomposition (kontrol.dmd): Dynamic mode decomposition for time-series forecasting and modeling. For future model predictive control work.

While Kontrol was initially created for optimizing KAGRA control systems, the package is also suitable for other gravitational-wave detectors, including LIGO, Virgo, and future detectors, such as the Einstein Telescope due to their similarities.

To familiarize users with the package, step-by-step tutorials are provided. Upon finishing the tutorials, the users should be able to convert the scripts into usable ones interfacing real data that can be used for the physical systems.

• Documentation: https://kontrol.readthedocs.io/

• Repository: https://github.com/terrencetec/kontrol.git

Contents:

• Kontrol Home
• Getting Started
  • Dependencies
  • Install from PyPI
  • Install from source
  • Concept and Tutorials
• How to use Kontrol
• Tutorials
  • Basic Suspension Commissioning
  • Advanced Control Methods
  • General Utilities
• Kontrol API
  • Subpackages
  • Submodules
• Contact
• For Developers
  • Standards and Tools

Indices and tables

• Index

• Module Index

• Search Page

1

T. T. L. Tsang, T. G. F. Li, T. Dehaeze, C. Collette. Optimal Sensor Fusion Method for Active Vibration Isolation Systems in Ground-Based Gravitational-Wave Detectors. https://arxiv.org/pdf/2111.14355.pdf

2

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