Methods and Algorithms of Turbojet Engines Thrust Parameters Control Unerroric

This report shows a real way for solving the problem of turbojet engine thrust parameters control in flight. The purpose of the research is the formalization of the digital methods and its algorithms for turbojet engines thrust parameters control unerroric. The methods of deductive digital signal processing and combined method of system analysis and approximate synthesis are used for such research. It is described the digital algorithms of unerroric methods wich are based on rotor speed control for turbojet engines of twin-engine airliner by its power plant control system. There are given the calculation formulas for those algorithms.

An algebraic input–output equation for planar RRRP and PRRP linkages

In this paper, the algebraic input–output (IO) equations for planar RRRP and PRRP linkages are derived by mapping the linkage displacement constraints into Study’s soma coordinates and then using tangent half-angle substitutions to transform the trigonometric into algebraic expressions. Both equations are found to be equivalent to the one that has already been derived for RRRR linkages, giving exciting new insight into kinematic analysis and synthesis of planar four-bar linkages. The algebraic properties of the IO curve equations yield information regarding the topology of the linkage, such as the sliding position limits of the prismatic joints and (or) the angle limits of the rotational joints. Additionally, the utility of the equations is successfully demonstrated with two approximate synthesis examples.

Optical, IR and THz screens based on layered metal-dielectric-semiconductor structures

In this work, we consider multilayer coatings of metal-dielectric-semiconductor nanosized layers located on a transparent substrate and described on the basis of the Drude–Lorentz model that serve as multiband screen filters for different frequency ranges. Structures with several layers and quasi-periodic structures are investigated. A method of the approximate synthesis of band gap structures with two layers per period and three layers per period is proposed. For three layers, the difference in plasma frequencies allows one to extend the bands. It is shown that semiconductor layers made of narrow-band crystal materials like InSb are promising for THz-band structures with the ability to adjust the ranges by doping.

A Task-Driven Approach to Optimal Synthesis of Planar Four-Bar Linkages for Extended Burmester Problem

The classic Burmester problem is concerned with computing dimensions of planar four-bar linkages consisting of all revolute joints for five-pose problems. We define extended Burmester problem as the one where all types of planar four-bars consisting of dyads of type RR, PR, RP, or PP (R: revolute, P: prismatic) and their dimensions need to be computed for n-geometric constraints, where a geometric constraint is an algebraically expressed constraint on the pose, pivots, or something equivalent. In addition, we extend it to linear, nonlinear, exact, and approximate constraints. This extension also includes the problems when there is no solution to the classic Burmester problem, but designers would still like to design a four-bar that may come closest to capturing their intent. Machine designers often grapple with such problems while designing linkage systems where the constraints are of different varieties and usually imprecise. In this paper, we present (1) a unified approach for solving the extended Burmester problem by showing that all linear and nonlinear constraints can be handled in a unified way without resorting to special cases, (2) in the event of no or unsatisfactory solutions to the synthesis problem, certain constraints can be relaxed, and (3) such constraints can be approximately satisfied by minimizing the algebraic fitting error using Lagrange multiplier method. We present a new algorithm, which solves new problems including optimal approximate synthesis of Burmester problem with no exact solutions.

A Flexible Discrete Building Block Synthesis Approach As Basis for the Design of Planar Linkages

In this paper we present a computational approximate synthesis procedure for the planar RR chain. Our approach is based on a grid search and takes an arbitrary amount of user-defined task positions for the two outer bodies of the chain and restrictions for both joints into account. The result of this synthesis approach is not only one optimal solution, but a list of several possible solutions which are ranked according to their performance. The approach aims at being used in building block-based synthesis procedures of more complex linkages. The method shall later be included into a CAD-integrated design tool for planar linkages.