SYNTHESIS OF A ROBUST ACS WITH A DYNAMIC COMPENSATOR AND A STATE OBSERVER WITH CORRECTIVE FEEDBACK BASED ON SIGMOID FUNCTIONS
DOI:
https://doi.org/10.18522/2311-3103-2026-1-%25pKeywords:
Robust bioreactor control, typical PID controller, dynamic compensator, state observer, sigma functionAbstract
A methodology for analyzing a robust automatic control system for linear dynamic control objects with a delay in the uncertainty of information about the parameters of the mathematical model and interference in the measured signals is described. The system implements a widely used PID controller and a dynamic compensator (DC) for the inertial part of the control object, implemented using estimates of state variables obtained on the basis of a state observer (SO). It is noted that any stability criterion can be used for the asymptotic stability of the controller and observer, but to ensure the maximum degree of stability and the required quality indicators of the transient process, it is convenient to use the maximum degree of stability criterion. In this paper, instead of derivatives obtained by differentiation, it is proposed to use in the dynamic compensator of the inertia of the object estimates of the state variables of the object obtained with the help of a state observer. Another difference from the known ones is the use of sigmoid functions in the corrective feedback of the state observer and the implementation of an additional effect to the main one based on the estimation error, compensating for external disturbance at the input of the object. The parametric synthesis of a state observer was used to study the impact of disturbances and noise on the performance of an automated control system (ACS) for an industrial interval-defined plant with various parameters. A robust typical PID controller with optimal parameters for maximum stability was calculated, taking into account the compensation of the inertial part of the object. For this purpose, a dynamic compensator (DC) was implemented using the parameters of a nominal (calculated) model of the object with the worst combination of parameters obtained on the basis of the interval model of the control object with a delay. The conducted research has established that the structure of the ACS with a typical PID controller with a sequential dynamic compensator for the inertia of the object and a state observer with corrective feedback based on sigma functions ensures the simplicity of the ACS synthesis methodology that is robust to changes in the parameters of the object and the action of unmeasured disturbances and uncontrolled interference.
References
1. Lubentsov V.F., Luzhevskiy N.O., Lubentsova E.V. Analiz podkhodov k sintezu sistem upravleniya ob"yektami s zapazdyvaniyem s ispol′zovaniyem nablyudateley sostoyaniya [Analysis of approaches to the synthesis of control systems for objects with delay using state observers]. Elektronnyy setevoy poli-tematicheskiy zhurnal «Nauchnyye trudy KubGTU» [Electronic network polythematic journal «Scientific works of KubSTU»], 2024, No 4, pp. 122-132.
2. Pukhov G.E., Zhuk K.D. Sintez mnogosvyaznykh sistem upravleniya po metodu obratnykh operatorov [Synthesis of Multivariate Control Systems Using the Inverse Operator Method]. Kiev: Naukova dumka, 1966, 218 p.
3. Izerman R. Tsifrovye sistemy upravleniya: transl. from Engl. [Digital Control Systems: Translated from English]. Moscow: Mir, 1984, 541 p.
4. Luzhevskiy N.O., Shakhray E.A., Lubentsov V.F., Lubentsova E.V. Analiz i sintez robastnykh regulya-torov s tipovymi zakonami regulirovaniya dlya kvazistatsionarnykh ob"yektov s zapazdyvaniyem [Anal-ysis and synthesis of robust regulators with standard control laws for quasi-stationary objects with de-lay], Pribory i sistemy. Upravleniye, kontrol′, diagnostika [Instruments and Systems. Control, Monitor-ing, Diagnostics], 2024, No. 5, pp. 24-31.
5. Krasnova S.A., Utkin A.V. Sigma-funktsiya v zadachakh sinteza nablyudateley sostoyaniy i vozmush-cheniy [Sigma Function in Problems of Synthesis of State and Disturbance Observers], Problemy up-ravleniya [Problems of Control], 2015, No. 5, pp. 27-36.
6. Potapenko E.M., Kazurova A.E. Osnovy teorii avtomaticheskogo upravleniya [Fundamentals of Auto-matic Control Theory]. Zaporozh'e: ZNTU, 2007, 162 p.
7. Denisenko V. PID-regulyatory: printsipy postroyeniya i modifikatsii. Chast′ 1 [PID Controllers: Princi-ples of Design and Modification. Part 1], Sovremennyye tekhnologii avtomatizatsii [Modern Automation Technologies], 2006, No. 4, pp. 66-74.
8. Tutov I.A. Sistema avtomaticheskogo regulirovaniya davleniya vnutripromyslovoy gazoraspredelitel′noy seti [Automatic pressure control system for an in-field gas distribution network]. Aktual′nyye problemy gumanitarnyy i yestestvennykh nauk. Chast′ 1 [Actual problems of humanitarian and natural sciences, Part 1], 2013, No. 11 (58), pp. 118-121.
9. Shubladze A.M., Popad′ko V.E., Yakusheva A.A., Kuznetsov S.I. Issledovaniye optimal′nykh po stepeni ustoychivosti resheniy pri PID upravlenii. Chast′ 1 [Study of optimal solutions in terms of stability un-der PID control. Part 1], Upravleniye bol′shimi sistemami: sbornik trudov [Control of large systems: collected papers], 2008, Issue. 22, pp. 86-100.
10. Aleksandrov A.G., Palenov M.V. Sostoyaniye i perspektivy razvitiya adaptivnykh PID-regulyatorov [Status and development prospects of adaptive PID controllers], Avtomatika i telemekhanika [Automa-tion and Telemechanics], 2014, No 2, pp. 16-30.
11. Kolpikov Yu.G., Lubentsov V.F., Oprishko A.A., Belova D.A., Shubladze A.M. Ob osobennostyakh ispol′zovaniya adaptivnogo PI-regulyatora s aktivnoy identifikatsiyey [On the Features of Using an Adaptive PI Controller with Active Identification], Pribory i sistemy upravleniya [Control Instruments and Systems], 1989, No. 4, pp. 26-27.
12. Lubentsova E.V. Proportsional′no-integral′no-differentsial′nyy regulyator [Proportional-integral-differential controller]: Patent RF, no 2234116 C1, 2004.
13. Gayduk A.R. Teoriya i metody analiticheskogo sinteza sistem avtomaticheskogo upravleniya (polinomi-al′nyy podkhod) [Theory and Methods of Analytical Synthesis of Automatic Control Systems (Polyno-mial Approach)]. Moscow: Fizmalit, 2012, 360 p.
14. Dudnikov E.G. Avtomaticheskoye upravleniye v khimicheskoy promyshlennosti [Automatic Control in the Chemical Industry]. Moscow: Khimiya, 1987, 368 p.
15. Gayvoronskiy S.A., Yezangina T.A., Sobol′ A.V. Sintez sistem upravleniya maksimal′noy robastnoy stepeni ustoychivosti na osnove vershinnykh kriticheskikh kornevykh diagramm [Synthesis of Maxi-mum Robust Stability Control Systems Based on Vertex Critical Root Diagrams], Mekhatronika, avtomatizatsiya, upravleniye [Mechatronics, Automation, Control], 2023, No. 24 (10), pp. 519-525.
16. Tychinin A.V. Strukturno-parametricheskiy sintez sistemy granichnogo upravleniya ob"ektom s raspre-delennymi parametrami metodami obratnoy dinamiki: spetsial'nost' 05.13.01 "Sistemnyy analiz, uprav-lenie i obrabotka informatsii (po otraslyam)": avtoref. diss. … kand. tekh. nauk [Structural-parametric synthesis of a boundary control system for an object with distributed parameters using inverse dynamics methods: abstract cand. of eng. sc. diss.]. Samara, 2008, 22 p.
17. Filimonov A.B., Filimonov N.B. K voprosu sinteza sistem mnogorezhimnogo regulirovaniya [On the issue of synthesis of multimode control systems], Journal of Advanced Research in Technical Science [Journal of Advanced Research in Technical Science], 2020, No. 18, pp. 41-49.
18. Remizova O.A., Syrokvashin V.V., Fokin A.L. Sintez robastnykh sistem upravleniya s tipovymi regulya-torami [Synthesis of robust control systems with standard controllers]. Izvestiya vysshikh uchebnykh zavedeniy. Priborostroyeniye [News of higher educational institutions. Instrument engineering], 2015, Vol. 58, No. 12, pp. 966-972.
19. Tendentsii razvitiya metodov sinteza sistem avtomaticheskogo upravleniya (SAU) [Trends in the Devel-opment of Methods for Synthesizing Automatic Control Systems (ACS). Available at: https://gigabaza.ru/doc/112825-pall.html (accessed 25 October 2025).
20. Fokin A.L. Sintez robastnykh sistem upravleniya tekhnologicheskimi protsessami s tipovymi regulya-torami [Synthesis of Robust Process Control Systems with Standard Controllers], Izvestiya Sankt-Peterburgskogo gosudarstvennogo tekhnologicheskogo instituta (tekhnicheskogo universiteta) [Bulletin of the St. Petersburg State Technological Institute (Technical University)], 2014, No. 27 (53), pp. 101-106.
21. Lubentsova E.V., Lubentsov V.F. Postroyeniye optimal′nykh po bystrodeystviyu sistem stabilizatsii [Construction of stabilization systems with optimal response time], Matematicheskiye metody v tekhnike i tekhnologiyakh: MMTT-2000: Sb. tr. 13 Mezhdunar. nauch. konf. [Mathematical methods in engineering and technology: MMTT-2000: Collection of works of the 13th International scientific conference]: In 7 vol. Vol. 6. St. Petersburg: St. Petersburg State Technological Institute (Technical University), 2000, pp. 272-273.
22. Antipov A.S., Krasnova S.A., Utkin V.A. Sintez invariantnykh nelineynykh odnokanal′nykh sistem slezheniya s sigmoidal′nymi obratnymi svyazyami s obespecheniyem zadannoy tochnosti slezheniya [Synthesis of invariant nonlinear single-channel tracking systems with sigmoid feedbacks ensuring a specified tracking accuracy], Avtomatika i telemekhanika [Automation and Telemechanics], 2022,
No 1, pp. 40-66.
23. Gouze J.-L., Rapaport А., Hadj-Sadok Z. Interval observers for uncertain biological systems, Ecological modeling, Issue 133 (1), рр. 45-56.
24. Bernard О., Gouze J. L. Closed loop observers bundle for uncertain biotechnological models, Journal of Process Control, October 2004, Vol, 14. Issue 7, рр. 765-774.
25. Alessan-dri A., Baglietto M., Battistelli G.Design of state estimators for uncertain linear systems using quadratic boundedness, Automatica, 2006, Vol, 42, рр. 497-502.
26. Khar′kovskaya T.A., Kremlev A.S., Sabirova D.M., Efimov D.V., Raissi T. Interval′nyy nablyudatel′ dlya modeli biologicheskogo reaktora [Interval observer for a biological reactor model], Nauchno-tekhnicheskiy vestnik informatsionnykh tekhnologiy, mekhaniki i optiki. [Scientific and Technical Journal of Information Technologies, Mechanics and Optics], 2014, No 3 (91), pp. 39-45.
27. P′yavchenko T.A., Finayev V.I. Avtomatizirovannyye informatsionno-upravlyayushchiye sistemy [Auto-mated information and control systems]. Taganrog: Izd-vo TRTU, 2007, 271 p.








