Regions of robust relative stability for PI controllers and LTI plants with unstructured multiplicative uncertainty: A second-order-based example

This example-oriented article addresses the computation of regions of all robustly relatively stabilizing Proportional-Integral (PI) controllers under various robust stability margins α for Linear Time-Invariant (LTI) plants with unstructured multiplicative uncertainty, where the plant model with multiplicative uncertainty is built on the basis of the second-order plant with three uncertain parameters. The applied graphical method, adopted from the authors’ previous work, is grounded in finding the contour that is linked to the pairs of P–I coefficients marginally fulfilling the condition of robust relative stability expressed using the H∞ norm. The illustrative example in the current article emphasizes that the technique itself for plotting the boundary contour of robust relative stability needs to be combined with the precondition of the nominally stable feedback control system and with the line for which the integral parameter equals zero in order to get the final robust relative stability regions. The calculations of the robust relative stability regions for various robust stability margins α are followed by the demonstration of the control behavior for two selected controllers applied to a set of members from the family of plants.College of Polytechnics Jihlava, (INT/2022/0002); Grantová Agentura České Republiky, GA ČR, (21–45465L)Czech Science Foundation (GACR) [21-45465L]; College of Polytechnics Jihlava [INT/2022/0002

Proceedings of the twelfth target fabrication specialists` meeting

Research in fabrication for inertial confinement fusion (ICF) comprises at least three broad categories: targets for high energy density physics on existing drivers, ignition capsule fabrication, and cryogenic fuel layer formation. The latter two are being pursued primarily for the National Ignition Facility (NIF). Scientists from over 14 laboratories, universities, and businesses contributed over 100 papers on all aspects of ICF target fabrication. The NIF is well along in construction and photos of poured concrete and exposed steel added to the technical excitement. It was clear from the meeting that there has been significant progress toward the fabrication of an ignition target for NIF and that new techniques are resulting in higher quality targets for high energy density research