scholarly journals Development of an Automatic Elastic Torque Control System Based on a Two-Mass Electric Drive Coordinate Observer

Machines ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 305
Author(s):  
Andrey A. Radionov ◽  
Alexandr S. Karandaev ◽  
Vadim R. Gasiyarov ◽  
Boris M. Loginov ◽  
Ekaterina A. Gartlib
Keyword(s):  
Control System ◽  
Literature Review ◽  
Control Systems ◽  
Electric Drive ◽  
Rolling Mill ◽  
A Priori ◽  
Torque Control ◽  
Mass System ◽  
Loop Control ◽  
Plate Rolling

Development of control system based on digital twins of physical processes is a promising area of research in the rolling industry. Closed-loop control systems are developed to control the coordinates of two-mass electromechanical systems in order to limit the dynamic loads on the equipment of main rolling lines. These control systems are based on observers (digital shadows) that indirectly detect (reconstruct) the roll speed and the elastic torque of the shaft (spindle) in real time. Notably, observers are required to work fast in order to reconstruct transients attributable to shock (impact) loads. Literature review shows that the known observers, which use complex algorithms to compute coordinates, do not respond fast enough. The paper analyzes the kinematic diagram of Mill 5000, a plate rolling mill. It presents oscillograms that prove that the elastic torque does oscillate as the rolls grip the strip dynamically. The authors hereof have developed an observer that reconstructs the coordinates of the uncontrolled mass (the shaft) and the spindle torque from the parameters of the controlled mass, namely the torque and speed of the motor. The paper further rationalizes an approach that consists of simulating the processes on a model to further directly configure them on the object. The authors analyze the transients of the reconstructed two-mass system coordinates, which are associated with the rolls gripping the strip. The paper compares data against oscillograms recorded on the mill itself. The accuracy is satisfactory. The proposed observer has been used to developed a three-loop automatic speed control system for the uncontrolled mass. Controller configurations are substantiated. The paper shows coordinates obtained by simulation modeling as functions of time. It further presents experiments run on Mill 5000; the conclusions are that the amplitude and oscillations of the elastic torque drop significantly. The paper concludes with recommendations on industrial adoption of the observer and the novel electric drive coordinate control system. Study presented herein substantiates and implements a concept of developing algorithms that solve specific problems and are readily implementable on the existing equipment without need for additional computing devices. The contribution of the paper consists of stating and solving the problem of developing and testing an automatic elastic torque control system for the shaft of a heavy-duty rolling mill. This system has been implemented in the form of algorithms that run in the software of the existing industrial controllers (PLCs). It is simple and performs well. It does not need additional sensors or computers to be implemented, nor does it rely on complex computational algorithms. Such algorithms are based on computational tables that require a priori data on numerous process parameters. In our literature review, we have not come across any industrial implementation of such algorithms on hot-rolling mills.

Experimental Parametrization of the Dual-Mass Electromechanical System of a Rolling Mill

2021 ◽  
Vol 64 (3) ◽  
pp. 24-35
Author(s):  
Alexander Karandaev ◽  
◽  
Andrey Radionov ◽  
Boris Loginov ◽  
Olga Gasiyarova ◽  
...  
Keyword(s):  
Electric Drive ◽  
Rolling Mill ◽  
Torque Control ◽  
Electromechanical System ◽  
Model Parameters ◽  
Mass Model ◽  
Mass System ◽  
Iron And Steel ◽  
Electric Drives ◽  
Drive Control

Transients in electromechanical systems need to be modeled adequately if the existing electric drive control algorithms are to be improved, or new ones are to be developed. This fully applies to the electric drives of roll-ing mill stands. When studying such drives, one often needs to find a tradeoff between the complexity of Park-Gorev equation-based mathematical description of processes in variable frequency drives, and the capabilities of simpler models that adequately describe the processes relevant for each specific case. The latter include the known dual-mass model of the electromechanical system of a rolling mill stand featuring a flexible shaft and gaps in transmissions. Research presented herein covers the parameters of this model, which need to be ob-tained experimentally. The most accurate way to find the model parameters is to derive them from the oscillo-grams sampled on the object when running in typical transient. This particular paper addresses the electrome-chanical system of the horizontal stand in Plate Mill 5000 deployed at Magnitogorsk Iron and Steel Works (MMK PJSC). The paper substantiates the methodology behind parametrizing the system and shows how to cal-culate the moments of inertia of rotating masses from oscillograms of unloaded drive acceleration. To showcase the method, the paper presents finding the stiffness factor of an elastic coupling from the transients recorded when halting the electric drive. Focus is made on finding the time constants of the internal torque control cir-cuit as approximated by first-order or second-order filters. By comparing the simulation output against the os-cillograms sampled on the mill itself, the model was proven to adequately compute the parameters of the object. The paper concludes with recommendations on how the developed methods could be used to find the parame-ters of a dual-mass system when modeling the electric drives in rolling mills. The conclusions outline possible further research.

Tangible Programming for Basic Control System New Frameworks to Engineering Education for Children

2014 ◽  
Vol 931-932 ◽  
pp. 1298-1302
Author(s):  
Thiang Meadthaisong ◽  
Siwaporn Meadthaisong ◽  
Sarawut Chaowaskoo
Keyword(s):  
Control System ◽  
Engineering Education ◽  
Control Systems ◽  
Primary Schools ◽  
Closed Loop ◽  
Open Loop ◽  
Closed Loop Control ◽  
College Level ◽  
Loop Control ◽  
Tangible Programming

Programming control in industrial design is by its nature expert upon an example being Programmable Logic Controller (PLC). Such programmes are unsuitable for children or novices as they cannot understand how to use the programme. This research seeks to present tangible programming for a basic control system in new frameworks in engineering education for children. Such programmes could be for use in kindergartens, primary schools or general teaching where knowledge about basic control is required. Normally open-loop and closed-loop control system programming is taught at university and college level. This may be late as far as acquiring knowledge of basic control systems is concerned. Using tangible programming without a computer but instructions and interface, relay and motor could result in children in kindergartens and primary schools being able to programme open-looped control systems which mix chemicals or closed-loop control systems which control conveyor belts. However, the children would not be able to undertake programming using programmable control in a similar scenario.

The use of models with improved characteristics in the missile control system

2020 ◽  
Keyword(s):  
Control System ◽  
Control Systems ◽  
A Priori ◽  
The State ◽  
State Variables ◽  
Control Loop ◽  
Fundamental Diagram ◽  
Management Efficiency ◽  
Control Matrix ◽  
Improved Characteristics

A fundamental diagram of a control system for missiles of various classes is investigated. A functional diagram of a control system with an intelligent component for long-range aerodynamic rockets returning to the atmosphere is developed. It is proposed to use in the control loop an ensemble of a priori missile models and models of external influences. It is proposed to improve the accuracy of control systems with an intelligent component by increasing the degree of controllability of the state variables for a priori models. The most convenient numerical criterion of controllability degree for of the state variables of the models is presented. The results of mathematical modeling showed a slight increase in the efficiency of missile control with an increase in the degree of controllability of the pitch angle by changing the coefficients of the control matrix. Keywords rocket; control system; intelligent component; an action acceptor; a priori model; controllability; degree of controllability; management efficiency

The Technology Study of Direct Torque Control Method for Permanent Magnet Synchronous Motor

2013 ◽  
Vol 341-342 ◽  
pp. 1013-1017
Author(s):  
Yi Ming Li ◽  
Wei Huang ◽  
Peng Jin ◽  
Jun Rong
Keyword(s):  
Control System ◽  
Permanent Magnet ◽  
Control Method ◽  
Permanent Magnet Synchronous Motor ◽  
Direct Torque Control ◽  
Synchronous Motor ◽  
Torque Control ◽  
Technology Study ◽  
Loop Control ◽  
Actual Application

According to the analysis of mathematical model for permanent magnet synchronous motor (PMSM), direct torque control(DTC) technology is introduced to the control system of PMSM. The paper builds dual-closed loop control system of PMSM, and the outer loop is speed loop, the inner loop is flux and torque loop, at the same time, the paper makes simulation in Matlab/Simulink. The simulation results show that the DTC technology significantly improves the dynamic performances of PMSM, and the control system is no overshoot, and has small flux response comparing with the conventional control methods of PMSM. So the application of DTC technology in PMSM provides a new thoughtful way for PMSM control system designing and debugging in actual application.

Symbolic Array Programming for Control System Analysis by Digital Computer

1968 ◽  
Vol 1 (6) ◽  
pp. 226-230 ◽  
Author(s):  
F. L. N-Nagy ◽  
O. Bar
Keyword(s):  
Control System ◽  
Control Systems ◽  
Digital Computer ◽  
System Analysis ◽  
Flow Diagram ◽  
Control Engineering ◽  
Loop Control ◽  
Novel Approach ◽  
Main Programme ◽  
Computational Form

A novel approach is provided for the analysis of multi-loop control systems by a digital computer introducing operational arrays, in which all the instructions are given through the data input. Changing parameters for optimisation purposes or the introducing of additional networks becomes a matter of changing the operational array in the data, leaving the main programme untouched. Although the method is general, only the frequency response of a control system is considered, but at the same time the way has been left open to expand the method as experience reveals the need for further facilities, i.e. root locus, time response, etc. The programme has been written in Algol, but the basic flow diagram can be easily converted into any other language. Whatever the language is, the programme provides the necessary software design facilities translated into control engineering terms in a readily usable computational form.

scholarly journals ALGORITHM FOR SYNTHESIS OF QUASI-OPTIMAL IN SPEED THIRD-ORDER SYSTEMS WITH APERIODIC SLIDING MODE

2021 ◽  
Vol 1 (38) ◽  
pp. 48-56
Author(s):  
O. Derets ◽  
O. Sadovoi ◽  
H. Derets
Keyword(s):  
Control System ◽  
Control Systems ◽  
Electric Drive ◽  
Sliding Mode ◽  
Block Diagram ◽  
Order System ◽  
Practical Implementation ◽  
Third Order ◽  
Relay Control ◽  
Electric Drives

The relevance of the work is due to the growing requirements for the dynamic characteristics of electric drives. In particular, together with the requirements of ensuring high accuracy and maximum at given speed limits, a typical task of designing such systems is the mandatory formation of transition diagrams in the form of monotonic time functions. The purpose of this study is to develop an adaptive algorithm for the synthesis of the third-order sliding mode control systems based on the method of N-i switching. Changing the shape of transient trajectory depends on the magnitude of the movement, which requires adaptation of the settings of the control system of the electric drive to the features of the current positioning mode. On the basis of the N-i switching method, an algorithm for synthesizing the parameters of a re-lay control system with cascade-subordinated structure, ensures non-oscillatory initiation of a sliding mode at various positioning modes, has been created. It is constructed by integrating the results of a number of previous works, in which the synthesis of relay control systems based on the analysis of the roots of the sliding equation of the position regulator is performed. This algorithm cannot be formally considered as an optimization tool due to the incompatibility of this problem with the aperiodization taken as the purpose, which comes about for certain forms of transient trajectories. But for such cases, the loss of performance relatively optimal one is negligible. Thus, the result of the application of the proposed algorithm in most practically significant cases is an optimal third-order system with aperiodic entry into the sliding mode. When controlling the electric drive, such a system will ensure the monotonous nature of the movement of the working body of the electromechanical system. The developed block diagram is focused on the practical implementation of the algorithm by the software of controllers of precision electric drives.

scholarly journals Control System Design for 16/6/8 Double-Stator Bearingless Switched Reluctance Motor

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Chuanyu Sun ◽  
Hang Yang ◽  
Shangke Han ◽  
Hongchang Ding ◽  
Jiaqing Li ◽  
...  
Keyword(s):  
Control System ◽  
Levitation Force ◽  
Switched Reluctance Motor ◽  
Torque Ripple ◽  
Torque Control ◽  
Strong Nonlinearity ◽  
Loop Control ◽  
Switched Reluctance ◽  
State Process ◽  
Reluctance Motor

The 16/6/8 double-stator bearingless switched reluctance motor (DSBSRM) is used as the object of study in this paper. To solve the problem of torque and levitation force ripples in this motor, a control system direct force control (DFC) and direct instantaneous torque control (DITC) based on the torque sharing function (TSF) are proposed. With the strong nonlinearity and approximation capability of radial basis function neural networks, the torque and levitation force observer are designed. The observed torque and levitation forces are used as feedback for the internal loop control, which is combined with the external loop control to make a double closed-loop control. In order to further improve the output torque and system robustness and suppress the torque ripple in steady-state process, the motor winding method is optimized and a set of switching angles is added on the basis of TSF. The simulation results verify the effectiveness and superiority of the proposed control method. It effectively suppresses speed ripple and reduces torque and levitation force fluctuations and rotor radial displacement jitter.

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