Neural Modelling of Dynamic Systems with Time Delays Based on an Adjusted NEAT Algorithm

A problem related to the development of an algorithm designed to find an architecture of artificial neural network used for black-box modelling of dynamic systems with time delays has been addressed in this paper. The proposed algorithm is based on a well-known NeuroEvolution of Augmenting Topologies (NEAT) algorithm. The NEAT algorithm has been adjusted by allowing additional connections within an artificial neural network and developing original specialised evolutionary operators. This resulted in a compromise between the size of neural network and its accuracy in capturing the response of the mathematical model under which it has been learnt. The research involved an extended validation study based on data generated from a mathematical model of an exemplary system as well as the fast processes occurring in a pressurised water nuclear reactor. The obtaining simulation results demonstrate the high effectiveness of the devised neural (black-box) models of dynamic systems with time delays.Comment: Conference pape

A selection of PID type controller settings via LQR approach for two-wheeled balancing robot

The problem of PID type controller tuning has been addressed in this paper. In particular, a method of selection of PD settings based on the solution of linear-quadratic optimisation problem using the energy criterion has been investigated. Thus, the possibility of transforming optimal settings of the linear-quadratic regulator into the settings of the controller in the classical control system has been given. The presented methodology has been used during synthesis of control system for a two-wheeled balancing robot. Finally, the performance of the proposed control system has been validated by simulation in Matlab-Simulink environment with the use of a two-wheeled balancing robot model.Comment: Conference pape

An automatic selection of optimal recurrent neural network architecture for processes dynamics modelling purposes

A problem related to the development of algorithms designed to find the structure of artificial neural network used for behavioural (black-box) modelling of selected dynamic processes has been addressed in this paper. The research has included four original proposals of algorithms dedicated to neural network architecture search. Algorithms have been based on well-known optimisation techniques such as evolutionary algorithms and gradient descent methods. In the presented research an artificial neural network of recurrent type has been used, whose architecture has been selected in an optimised way based on the above-mentioned algorithms. The optimality has been understood as achieving a trade-off between the size of the neural network and its accuracy in capturing the response of the mathematical model under which it has been learnt. During the optimisation, original specialised evolutionary operators have been proposed. The research involved an extended validation study based on data generated from a mathematical model of the fast processes occurring in a pressurised water nuclear reactor.Comment: 32 pages, 17 figures, code availabl

A control system design for two-wheeled balancing robot

W niniejszym artykule rozważony został problem sterowania dwukołowym robotem balansującym. Celem zaprezentowanych prac było zaprojektowanie systemu sterowania tego typu obiektem z wykorzystaniem metod nowoczesnej teorii sterowania. W ramach syntezy, bazując na wyprowadzonym w oparciu o zasady dynamiki Newtona modelu, dobrana została struktura systemu sterowania w postaci regulatora wykorzystującego sprzężenie zwrotne od stanu oraz sprzężenie w przód od zadanej wartości prędkości liniowej robota. Dobór wzmocnień regulatora w sprzężeniu od stanu wykonano z wykorzystaniem technologii sterowania optymalnego z kwadratowym wskaźnikiem jakości. Ponadto, z uwagi na niedostateczną jakość pomiarów używanych w sterowaniu, opracowano dyskretny filtr Kalmana. Jakość opracowanego rozwiązania została przetestowana, przede wszystkim symulacyjnie, w środowisku Matlab/Simulink. Zawarte rozważania agregują wiedzę umożliwiającą zaprojektowanie systemu sterowania obiektami tej klasy, co może być użyteczne szczególnie w różnych aplikacjach inżynierskich.A two-wheeled balancing robot is one type of structures based on the principle of a mobile inverted pendulum. The main aim of controlling a balancing robot is to stabilise it at the upper equilibrium point and to enable its movement with the set speed. In this paper, a synthesis of a balancing robot control system has been given. Within its framework, based on the model using Newton's laws, a feedforward state-feedback control system structure has been designed. The controller parameter values have been computed using optimisation tools. More specifically, the linear-quadratic regulator (LQR) has been designed. Moreover, due to the insufficient quality of measurements used in the control system, a linear discrete Kalman filter has been developed. The complete control system has been implemented and tested in the Matlab/Simulink environment

PID-type regulators tuning by using state-feedback control design

Układy sterujące typu PID są jednymi z najbardziej popularnych regulatorów wykorzystywanych w układach regulacji. W związku z tym znanych jest szereg metod doboru wartości ich parametrów (nastaw). Obok różnych metod inżynierskich czy analitycznych strojenia tego typu regulatorów, dostępne są również podejścia bazujące na optymalizacji. Wskaźnikiem jakości znajdującym w nich zastosowanie jest np. całka z kwadratu uchybu. W artykule przedstawiono alternatywny sposób wyznaczania nastaw regulatora z rodziny PID bazujący na rozwiązaniu liniowokwadratowego zadania optymalizacji wykorzystującego kryterium energetyczne. Uszczegóławiając, pokazano możliwość transformacji optymalnych nastaw regulatora bazującego na sprzężeniu zwrotnym od stanu obiektu w nastawy regulatora w klasycznym układzie regulacji. Jako aplikację wykorzystano nieliniowy matematyczny model dynamiki podwójnego odwróconego wahadła.The PID-type regulators are one of the most commonly used in control systems. Therefore, there are many different methods of selecting values of their parameters. Apart from various engineering or analytical methods of tuning such controllers, there are also approaches based on optimisation. In the latter case, a typical performance index is integral square error (ISE). In this paper, an alternative method of PID parameters tuning has been presented. This approach is based on a solution of the linear-square optimisation task with energy-based performance index. In the result, a state-feedback controller is obtained. Subsequently, the state-feedback gains are translated into PID regulator parameters. The proposed approach has been illustrated using a non-linear mathematical model of a double inverted pendulum

Estimation of the angular position of a two–wheeled balancing robot using a real IMU with selected filters

A low–cost measurement system using filtering of measurements for two–wheeled balancing robot stabilisation purposes has been addressed in this paper. In particular, a measurement system based on gyroscope, accelerometer, and encoder has been considered. The measurements have been corrected for deterministic disturbances and then filtered with Kalman, a–b type, and complementary filters. A quantitative assessment of selected filters has been given. As a result, the complete structure of a measurement system has been obtained. The performance of the proposed measurement system has been validated experimentally by using a dedicated research rig

A comprehensive approach to double inverted pendulum modelling

The problem of mathematical modelling and indication of properties of a DIP has been investigated in this paper. The aim of this work is to aggregate the knowledge on a DIP modelling using the Euler-Lagrange formalism in the presence of external forces and friction. To indicate the main properties important for simulation, model parameters identification and control system synthesis, analytical and numerical tools have been used. The investigated properties include stability of equilibrium points, a chaos of dynamics and non-minimum phase behaviour around an upper position. The presented results refer to the model of a physical (constructed) DIP system