Combined Control System for Structural and Parametric Uncertain Non-Affine Plants with Delay in Control

Author(s):  
E.L. Eremin ◽  
L.V. Nikiforova ◽  
E.A. Shelenok
Author(s):  
Alexander M. Abakumov ◽  
Pavel K. Kuznetsov

The problem of the temperature control at the outlet of gas cooling units of compressor stations of main gas pipelines is discussed. To solve the problemt, a discrete or frequency control of electric motors of fans of gas air cooling devices is used. The problems of electromagnetic compatibility that arise in typical power supply systems of gas cooling installations when connecting electric motors of fans through frequency converters are noted. A combined fan motor control system is considered, in which the electric motors are divided into two groups. The electric motors of the first group are connected to the network directly, the second through frequency converters. By reducing the number of electric motors connected to the network through frequency converters, the negative impact of frequency-controlled drives on the quality of electricity is reduced and the costs of modernization projects are reduced in comparison with the option of the variant using a frequency converter for each electric motor. The energy characteristics of the combined control system are analyzed. The relations that establish the relationship between the temperature difference at the cooling unit and the power of the fan motors for various control methods are obtained. The optimal control algorithm according to the criterion of maximum power saving is proposed, which provides for the interconnected control of the number of discrete-controlled motors and the speed of frequency-controlled drives. The variants of the implementation of the optimal control algorithm are discussed. Analytical expressions for power saving on the fan motor shaft in a combined system compared with a discrete one and a method for estimating energy savings are considered. The obtained results are recommended to be used to assess the technical and economic efficiency of projects for the modernization of electrical complexes of gas cooling units.


2021 ◽  
Vol 2096 (1) ◽  
pp. 012069
Author(s):  
E L Eremin ◽  
L V Nikiforova ◽  
E A Shelenok

Abstract The paper is devoted to consideration of the problem of constructing a discrete-continuous decentralized nonlinear combined control system for two-link robotic manipulator with restrictions in control signals. The mathematical model of the manipulator is presented as a two-channel dynamic plant with nonlinear cross-links. As methods for solving this problem V. M. Popov’s hyperstability criterion and the conditions of L-dissipativity are used. With the help of simulation, the quality of the proposed control system is shown. The results obtained in article may be useful for construction the control systems for manipulators with many degrees of freedom and also for control various mechanical systems.


2019 ◽  
Vol 2019 ◽  
pp. 1-11
Author(s):  
Xiaoli Li ◽  
Yan Shi

This paper focuses on the seismic isolation design of near-fault bridges under the seismic excitations of near-fault ground motions in high-intensity earthquake zones and proposes a combined control system using lead rubber bearings (LRBs) and cable displacement restrainers (CDRs) along with ductility seismic resistance for the reinforced concrete piers. As part of the performance-based seismic design framework, this study provides the quantitative design criteria for multilevel performance-based objectives of a combined control system under conditions of frequent earthquake (E1), design earthquake (medium earthquake), and rare earthquake (E2). Moreover, in this study, a preliminary performance-based seismic isolation design for a near-fault actual highway bridge in high-intensity earthquake zones (basic peak of ground acceleration 0.4 g) was developed. Using nonlinear time-history analysis of the actual bridge under near-fault ground motions, the feasibility of a performance-based design method was validated. Furthermore, to ensure the predicted performance of the isolated bridges during a strong earthquake, a relatively quantitative design in structural details derived from the stirrup ratio of piers, expansion joints gap, supported length of capping beams, and limited vertical displacement response was obtained.


IEEE Access ◽  
2019 ◽  
Vol 7 ◽  
pp. 159960-159970 ◽  
Author(s):  
Mingjiang Shi ◽  
Shun Guo ◽  
Lu Jiang ◽  
Zhiqiang Huang

2006 ◽  
Vol 50 (04) ◽  
pp. 344-354
Author(s):  
Ming-Chung Fang ◽  
Jhih-Hong Luo

In this paper, a hydrodynamic numerical model with a combined control system is developed to simulate a ship steering in waves. The combined control system includes the PD controller and the sliding mode controller. By way of the rudder operation, the PD controller integrated with a line-of-sight (LOS) guidance system is used to control the track keeping, whereas the sliding mode controller is mainly chosen to reduce the roll motion. Different heading angle, wave height, wavelength, and initial speed are selected to investigate the combined control ability of the autopilot system. From simulation results, we find that this combined control system indeed works well, either for the ship roll motion reduction or for the ship track keeping in waves.


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