Аналитическое решение задачи синтеза трехзвенного ступенчатого чебышевского СВЧ-фильтра

The problem of synthesis of the three–link stepped Chebyshev's microwave filter is reduced to two independent fourth degree equations, including a single link wave impedance as unknown. The solution of Descartes – Euler is applied to these equations. It is proved, that in case of wave impedances of extreme links are equal, the problem of the filter synthesis has two solutions. Identical phase–frequency responses correspond to these solutions. It is proved, that for every one of links a product of the wave impedances, relating to these solutions, is equal to a square of the wave impedance of transmission line, including filter.

Optimum control of a flexible single link manipulator with Artificial Bee Colony Algorithm

This paper presents a stable control for a single link flexible manipulator. The flexible manipulator is considered as Euler–Bernoulli beam, and its dynamic model is developed based on assumed mode method. Position and vibration control are realised with a single controller as motor torque. The controller has three parameters that must be selected. In this paper, the main motivation is to find the suitable parameter values to generate optimum torque values in every sampling time. In order to achieve this goal, Artificial Bee Colony Algorithm is performed, and the controller parameters are optimised simultaneously in every sampling period. Simulations verify that the manipulator achieves the position control objective, and the vibration is suppressed simultaneously even with different payloads with the proposed optimisation method.

Sliding Mode Robust Active Disturbance Rejection Control for Single-Link Flexible Arm with Large Payload Variations

This paper proposes a novel robust control scheme for tip trajectory tracking of a lightweight flexible single-link arm. The developed control scheme deals with the influence of tip payload changes and disturbances during the working process of the flexible arm, thus realizing the accurate tracking for the tip reference trajectory. The robust control scheme is composed of an inner loop and an outer loop. The inner loop adopts the traditional PD control, and an active disturbance rejection control (ADRC) with a sliding mode (SM) compensation is designed in the outer loop. Moreover, the sliding mode compensation is mainly used to cope with the disturbance estimation error from the extended state observer (ESO), by which the insensitivity to tip payload variations and strong disturbance resistance is achieved. Finally, some numerical simulations are performed to support the theoretical analysis. The results show that the system is more robust to the tip mass variations of the arm and more resistant to the external torque after adding the sliding mode robustness term to the ADRC.

Time-Delayed Acceleration Feedback Control of a Single-Link Flexible Manipulator Using Kalman Filter

The design problem of a discrete controller with time delay and acceleration feedback for a single-link flexible manipulator system is addressed in this paper. The dynamical model of a single-link flexible manipulator system is presented by the adoption of the finite element method and Lagrange’s equation. Based on the random-walk process and the discrete reduction method, an augmented discretized delay-free state derivate space equation containing the random noise is established. An acceleration-based Kalman filtering method is developed in order to estimate the system state and external excitation necessary for the controller design. In light of the estimated augmented states, a hybrid controller that combines a feedback control algorithm and a feedforward control algorithm is designed according to optimal control theory and Moore–Penrose theory. Numerical simulation results show that the proposed controller can damp out the vibration response of the flexible manipulator system effectively upon external excitations. Moreover, it is further revealed that the control performance of the presented method can be improved by adding the time delay appropriately.

Osteosarcopenic obesity in cardiovascular patients. Controversial and open issues

See “Inflammaging in the pathogenesis of chronic non-communicable diseases”, Kim O. T. in Opinion of invited editor, pp. 54-55.The study of osteosarcopenic obesity (OSO) in patients with cardiovascular diseases (CVDs) in recent years has caused a dis-cussion on common pathogenesis of atherosclerosis, obesity, progressive loss of skeletal and muscle mass. Are these processes independent age-related conditions or comorbidities with common links of pathogenesis? The aim of this review was to analyze studies on OSO in patients with CVDs. We used following electronic databases: PubMed, Clinical Trials, Google Scholar, www.elibrary.ru. Based on this analysis, modern ideas on the etiology, epidemiology and pathogenesis of OSO in elderly and senile patients with atherosclerosis were described. The authors concluded that absence of standards for OSO diagnosis and inadequate clinical suspicion of specialists during routine examination is one of the main causes of its insufficient detection in elderly patients with CVDs. The results of analyzed studies allow us to consider the OSO and atherosclerotic changes as a single link of cardiovascular continuum. Eliminating the negative effect of chronic inflammation on human body should be considered as a key mechanism in the treatment of OSO and atherosclerosis. However, more research is needed in this area.