scholarly journals Dual‐rate control system extension using the null space of a closed‐loop system

2019 ◽  
Vol 15 (1) ◽  
pp. 135-139
Author(s):  
Ryota Yasui ◽  
Natsuki Kawaguchi ◽  
Takao Sato ◽  
Nozomu Araki ◽  
Yasuo Konishi
1995 ◽  
Vol 117 (4) ◽  
pp. 484-489
Author(s):  
Jenq-Tzong H. Chan

A correlation equation is established between open-loop test data and the desired closed-loop system characteristics permitting control system synthesis to be done on the basis of a numerical approach using experimental data. The method is applicable when the system is linear-time-invariant and open-loop stable. The major merits of the algorithm are two-fold: 1) Arbitrary placement of the closed-loop system equation is possible, and 2) explicit knowledge of an open-loop system model is not needed for the controller synthesis.


Author(s):  
Hoseinali Borhan ◽  
Edmund Hodzen

In this paper, a systematic model-based calibration framework basing on robust design optimization technique is developed for engine control system. In this framework, the control system is calibrated in an optimization fashion where both performance and robustness of the closed-loop system to uncertainties are optimized. The proposed calibration process has three steps: in the first step, the optimal performance of the system at the nominal conditions, where the effects of uncertainties are ignored, is computed by formulation of the controller calibration as an optimization problem. The capabilities of the controller are fully explored at nominal conditions. In the second step, the robustness and sensitivity of a selected control design to the system uncertainties are analyzed using Monte Carlo simulation. In the third step, robust design optimization is applied to optimize both performance and robustness of the closed-loop system to the uncertainties. The robustness capabilities of the controller are fully explored and the one that satisfies both performance and robustness requirements is selected. This process is implemented for the calibration of an advanced diesel air path control system with a variable geometry turbocharger (VGT) and dual loop exhaust gas recirculation (EGR) architecture.


2021 ◽  
Vol 2070 (1) ◽  
pp. 012102
Author(s):  
V Venkatachalam ◽  
M Ramasubramanian ◽  
M Thirumarimurugan ◽  
D Prabhakaran

Abstract This paper presents an Investigation on the stability of network controlled temperature control system having Time-Invariant feedback delays, by utilizing a direct method for TDS stability analysis. A PI controller based stability analysis for temperature control system with Time invariant feedback loop delay has been constructed in this paper. The stability problem has been formulated based on the transfer function model of the closed loop system with various time delays. For different subsets of the controller parameters, based on the stability criterion’s maximal permissible bound of the network link delay that the closed loop system can accommodate without losing the stability has been computed. The effectiveness of the obtained result was validated on a benchmark temperature control system using MATLAB simulation software.


Author(s):  
Syed Mujtaba Mahdi Mudassir ◽  
Faheem Ahmed Khan ◽  
Shaziya Sultana

A control system is a set of mechanical or electronic devices that regulates other devices or systems by way of control loops. Typically, control systems are computerized. The mode of operation in a Control System where controlling variables is a function of the system and the structure is changed knowingly according to set of rules, which are already declared: for example a sensor based  system, is called as sliding control mode where the feedback control system response is limited and revolves around surface in the space to a point of equilibrium. In this mode of schemes, a switching variable dictates which form of control is to be used at a given instant, depending on the position of the state from the surface. First a set of points for which the switching function is null is used called as sliding surface. Sliding Mode Control (SMC) is a very robust technique which can handle sudden and large changes in dynamics of the system which can be applied to many areas like controlling of motor, aircraft and spacecraft, process control and power systems. SMC is one of the best tool in the industry to design controllers for the systems which has variable values, and provides robust properties against matched uncertainties, However,this use of SMC can only be achieved after the occurrence of the sliding mode. Before the occurrence of the switching function as null i.e. during the reaching phase, the system is affected by even matched ones. Several first order SMC applications for linear and nonlinear systems can be found in the literature [1]. Hence to eliminate the reaching phase and to make sure the ruggedness of the system throughout the entire closed-loop system response Integral Sliding Modes are used. In this paper a design procedure for sliding mode controllers for better control of voltage is applied, and then the ideas implemented are extended to all integral sliding modes in order to ensure optimum operation of entire system response[2]. Necessary conditions for the existence of sliding modes are also given. The closed-loop system is also proved to be exponentially stable. Simulation and experimental tests using the prototype of controlled DC-DC  CUK converter were performed to validate the proposed control approach.


2016 ◽  
Vol 8 (5) ◽  
pp. 540-547
Author(s):  
Tomas Eglynas ◽  
Audrius Senulis ◽  
Marijonas Bogdevičius ◽  
Arūnas Andziulis ◽  
Mindaugas Jusis

The main control object of Quay crane, which is operating in seaport intermodal terminal cargo loading and unloading process, is the crane trolley. One of the main frequent problem, which occurs, is the swinging of the container. This swinging is caused not only by external forces but also by the movement of the trolley. The research results of recent years produced various types of control algorithms by the other researchers. The control algorithms are solving separate control problems of Quay crane in laboratory environment. However, there is still complex control algorithm design and the controller’s parameter estimation problems to be solved. This paper presents mathematical model of the Quay crane trolley mechanism with the suspended cargo. The mathematical model is implemented in Matlab Simulink environment and using Dormand-Prince solving method. The presented model of laboratory quay crane mathematical model is dedicated to parameter estimation of PID controller of closed loop system with the usage of S –form speed input profile. The article includes the dynamic model of the presented system, the description of closed loop system and modeling results. These results will be used as an initial information for the PID parameters estimation in real quay crane control system. The simu-lation of the model was performed using estimated values of controller. The sway influence of the cargo, the usage of the trolley speed input S-shaper and the PID controller was used to control the trolley speed. Jūriniame įvairiarūšiame terminale atliekant konteinerių krovos procesus, vienas iš krantinės kranų valdymo objektų yra vežimėlis. Viena iš problemų, su kuria susiduriama dažniausiai, yra konteinerio svyravimai, kuriuos, be išorinių veiksnių, taip pat sukelia ir vežimėlio judėji-mas. Remdamiesi paskutinių kelerių metų tyrimais, mokslininkai sukūrė įvairių valdymo algoritmų, kurie laboratorinėmis sąlygomis spren-džia atskiras krantinės kranų valdymo problemas. Tačiau kompleksinių ir efektyvių valdymo algoritmų ir jų valdymo sistemos parametrų nustatymo metodai vis dar kuriami ir tobulinami. Šiame darbe sudarytas krantinės krano vežimėlio su kabančiu kroviniu mechanizmo sis-temos matematinis modelis. Šis modelis realizuotas Matlab Simulink aplinkoje ir sprendžiamas taikant Dormand-Prince metodą. Sukurtas laboratorinio krantinės krano valdymo sistemos kompiuterinis modelis skirtas uždarosios valdymo sistemos PID valdiklio parametrams nustatyti, kai užduoties signalui taikomas S formos greičio kitimo profilis. Darbe pateiktas sistemos dinaminis modelis, aprašyta uždaroji valdymo sistema, pateikti kompiuterinio modeliavimo rezultatai, kuriuos planuojama panaudoti kaip pradinę informaciją realaus krano PID valdiklio parametrams derinti. Atlikta simuliacija naudojant nustatytas vertes ir įvertinti krovinio svyravimai taikant S formos greičio kitimo profilį kartu su PID valdikliu vežimėlio greičiui valdyti.


Author(s):  
K W Lee ◽  
S N Singh

The article presents a new non-certainty-equivalent adaptive (NCEA) longitudinal autopilot for the control of a missile based on the immersion and invariance theory. The interest here is to control the angle of attack of the missile in the presence of large parametric uncertainties. For the derivation of the control law, a backstepping design procedure is used. At each step of the design, certain filtered signals are generated for the synthesis of a stabilizing control signal and a parameter estimator. Using Lyapunov stability analysis, it is shown that in the closed-loop system, trajectory control of the angle of attack is accomplished, and the trajectories of the system are attracted to certain manifold in the space of state variables and parameter errors. For stability in the closed-loop system, an explicit analytical relation involving the controller gains is obtained. It may be pointed out that recently an adaptive autopilot based on the immersion and inversion theory has been designed, but it has stringent requirements because for its synthesis, the derivatives of the Mach number and angle of attack must be known, and a large number of parameters must be updated. The derived control system of this article is synthesized using only the state variables, and its identifier is of lower order. A traditional certainty-equivalent adaptive autopilot is also presented for comparison. Simulation results are obtained which show that the designed NCEA control system can accomplish angle of attack control despite large parametric uncertainties; and it can give better tracking performance than the traditional controller.


2016 ◽  
Vol 24 (4) ◽  
pp. 722-738 ◽  
Author(s):  
Atta Oveisi ◽  
Tamara Nestorović

A robust nonfragile observer-based controller for a linear time-invariant system with structured uncertainty is introduced. The [Formula: see text] robust stability of the closed-loop system is guaranteed by use of the Lyapunov theorem in the presence of undesirable disturbance. For the sake of addressing the fragility problem, independent sets of time-dependent gain-uncertainties are assumed to be existing for the controller and the observer elements. In order to satisfy the arbitrary H2-normed constraints for the control system and to enable automatic determination of the optimal [Formula: see text] bound of the performance functions in disturbance rejection control, additional necessary and sufficient conditions are presented in a linear matrix equality/inequality framework. The [Formula: see text] observer-based controller is then transformed into an optimization problem of coupled set of linear matrix equalities/inequality that can be solved iteratively by use of numerical software such as Scilab. Finally, concerning the evaluation of the performance of the controller, the control system is implemented in real time on a mechanical system, aiming at vibration suppression. The plant under study is a multi-input single-output clamped-free piezo-laminated smart beam. The nominal mathematical reduced-order model of the beam with piezo-actuators is used to design the proposed controller and then the control system is implemented experimentally on the full-order real-time system. The results show that the closed-loop system has a robust performance in rejecting the disturbance in the presence of the structured uncertainty and in the presence of the unmodeled dynamics.


1986 ◽  
Vol 120 (1) ◽  
pp. 369-385 ◽  
Author(s):  
G. WEILAND ◽  
U. BÄSSLER ◽  
M. BRUNNER

An experimental arrangement was constructed which is based on the open-loop femur-tibia control system of two stick insect species (Carausius morosus and Cuniculina impigra). It could be artificially closed in the following way: the position of the tibia was measured by an optical device and this value was used to drive a penmotor which moved the receptor apodeme of the femoral chordotonal organ in the same way as in intact animals. This arrangement allows direct comparison of the behaviour of the open-loop and the closed-loop system as well as introducing an additional delay. The Carausius system has a phase reserve of only 30°-50° and the factor of feedback control approaches 1 between 1 and 2 Hz. This agrees with the observation that an additional delay of 70–200 ms produces long-lasting oscillations of 1–2 Hz. The Cuniculina system has a larger phase reserve and consequently a delay of 200 ms produced no oscillations. All experiments show that extrapolation from the open-loop system to the closed-loop system is valid, despite the non-linear characteristics of the loop. Consequences for servo-mechanisms during walking and rocking movements are discussed.


1986 ◽  
Vol 9 (6) ◽  
pp. 992-996 ◽  
Author(s):  
K. STANGL ◽  
A WIRTZFELD ◽  
G. GOBL ◽  
R. HEINZE ◽  
M. LAULE ◽  
...  

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