Some Interpretations Of Self-Tuning Pid Controllers

1994 ◽  
pp. 27-42
Author(s):  
Rubiyah Yusof ◽  
Marzuki Khalid ◽  
Sigeru Omatu

One of the most recent development in the theories of adaptive methods in the form of self-tuning algorithms is in the area of self-tuning PID controllers (STPID). These controllers are a class of adaptive controllers but are essentially PID controllers with the capabilities of tuning their parameters automatically online. To this end, the theories of these types of controllers are still in the infancy stage. In this paper, we provide some interpretations of a STPID through some analytical and simulation results, thereby lending way for a better understanding of the algorithms and some insight into the usefullness of the algorithm. The interpretations also serve as an aid in the selection of the tuning parameters of this algorithm which can be a time consuming activity if done dilligently.

1986 ◽  
Vol 19 (9) ◽  
pp. 260-266 ◽  
Author(s):  
A Carmon

The paper reviews the operation of an on-line continuously adaptive PID controller which uses an expert system approach to self-tune. The benefits of using continuously adaptive control have been demonstrated by trial installations and have produced financial returns running into six figure values per annum per loop. Indirect benefits such as better insight into plant controllability (used to indicate a need for plant maintenance) and faster plant startups have been identified by users. The paper stresses the need for experience feedback in developing the understanding of the industry in the correct and best use of this new technology, a technology which promises to become the industry standard. An application guideline is provided and some limitations are pointed out. Some features that help make it a robust and secure product in a process control environment are also indicated.


2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Pradeep Reddy Punnam ◽  
Balaji Krishnamurthy ◽  
Vikranth Kumar Surasani

This work aims to study the structural and residual trapping mechanisms on the Deccan traps topography to elucidate the possible implementation of CO2 geological sequestration. This study provides an insight into a selection of stairsteps landscape from Deccan traps in the Saurashtra region, Gujarat, India. Various parameters affect the efficiency of the structural and residual trapping mechanisms. Thus, the parametric study is conducted on the modeled synthetic geological domain by considering the suitable injection points for varying injection rates and petrophysical properties. The outcomes of this study will provide insights into the dependencies of structural and residual trapping on the Deccan traps surface topography and injection rates. It can also establish a protocol for selecting the optimal injection points with the desired injection rate for the safe and efficient implementation of CO2 sequestration. The simulation results of this study have shown the dependencies of structural and residual trapping on the geological domain parameters.


TAPPI Journal ◽  
2009 ◽  
Vol 8 (1) ◽  
pp. 4-11
Author(s):  
MOHAMED CHBEL ◽  
LUC LAPERRIÈRE

Pulp and paper processes frequently present nonlinear behavior, which means that process dynam-ics change with the operating points. These nonlinearities can challenge process control. PID controllers are the most popular controllers because they are simple and robust. However, a fixed set of PID tuning parameters is gen-erally not sufficient to optimize control of the process. Problems related to nonlinearities such as sluggish or oscilla-tory response can arise in different operating regions. Gain scheduling is a potential solution. In processes with mul-tiple control objectives, the control strategy must further evaluate loop interactions to decide on the pairing of manipulated and controlled variables that minimize the effect of such interactions and hence, optimize controller’s performance and stability. Using the CADSIM Plus™ commercial simulation software, we developed a Jacobian sim-ulation module that enables automatic bumps on the manipulated variables to calculate process gains at different operating points. These gains can be used in controller tuning. The module also enables the control system designer to evaluate loop interactions in a multivariable control system by calculating the Relative Gain Array (RGA) matrix, of which the Jacobian is an essential part.


2020 ◽  
Vol 27 ◽  
Author(s):  
Fırat Kurt

: Oligopeptide transporter 3 (OPT3) proteins are one of the subsets of OPT clade, yet little is known about these transporters. Therefore, homolog OPT3 proteins in several plant species were investigated and characterized using bioinformatical tools. Motif and co-expression analyses showed that OPT3 proteins may be involved in both biotic and abiotic stress responses as well as growth and developmental processes. AtOPT3 usually seemed to take part in Fe homeostasis whereas ZmOPT3 putatively interacted with proteins involved in various biological processes from plant defense system to stress responses. Glutathione (GSH), as a putative alternative chelating agent, was used in the AtOPT3 and ZmOPT3 docking analyses to identify their putative binding residues. The information given in this study will contribute to the understanding of OPT3 proteins’ interactions in various pathways and to the selection of potential ligands for OPT3s.


Robotica ◽  
2021 ◽  
pp. 1-17
Author(s):  
Seyed Mostafa Almodarresi ◽  
Marzieh Kamali ◽  
Farid Sheikholeslam

Abstract In this paper, new distributed adaptive methods are proposed for solving both leaderless and leader–follower consensus problems in networks of uncertain robot manipulators, by estimating only the gravitational torque forces. Comparing with the existing adaptive methods, which require the estimation of the whole dynamics, presented methods reduce the excitation levels required for efficient parameter search, the convergence time, and the complexity of the regressor. Additionally, proposed schemes eliminate the need for velocity information exchange between the agents. Global asymptotic synchronization is shown by introducing new Lyapunov functions. Simulation results are provided for a network of 10 4-DOF robot manipulators.


Author(s):  
L F Campanile ◽  
R Jähne ◽  
A Hasse

Classical beam models do not account for partial restraint of anticlastic bending and are therefore inherently inaccurate. This article proposes a modification of the exact Bernoulli–Euler equation which allows for an exact prediction of the beam's deflection without the need of two-dimensional finite element calculations. This approach offers a substantial reduction in the computational effort, especially when coupled with a fast-solving schema like the circle-arc method. Besides the description of the new method and its validation, this article offers an insight into the somewhat disregarded topic of anticlastic bending by a short review of the published theories and a selection of representative numerical results.


2006 ◽  
Vol 519-521 ◽  
pp. 949-954 ◽  
Author(s):  
Beong Bok Hwang ◽  
J.H. Shim ◽  
Jung Min Seo ◽  
H.S. Koo ◽  
J.H. Ok ◽  
...  

This paper is concerned with the analysis of the forming load characteristics of a forward-backward can extrusion in both combined and sequence operation. A commercially available finite element program, which is coded in the rigid-plastic finite element method, has been employed to investigate the forming load characteristics. AA 2024 aluminum alloy is selected as a model material. The analysis in the present study is extended to the selection of press frame capacity for producing efficiently final product at low cost. The possible extrusion processes to shape a forward-backward can component with different outer diameters are categorized to estimate quantitatively the force requirement for forming forward-backward can part, forming energy, and maximum pressure exerted on the die-material interfaces, respectively. The categorized processes are composed of combined and/or some basic extrusion processes such as sequence operation. Based on the simulation results about forming load characteristics, the frame capacity of a mechanical press of crank-drive type suitable for a selected process could be determined along with securing the load capacity and with considering productivity. In addition, it is suggested that different load capacities be selected for different dimensions of a part such as wall thickness in forward direction and etc. It is concluded quantitatively from the simulation results that the combined operation is superior to sequence operation in terms of relatively low forming load and thus it leads to low cost for forming equipments. However, it is also known from the simulation results that the precise control of dimensional accuracy is not so easy in combined operation. The results in this paper could be a good reference for analysis of forming process for complex parts and selection of proper frame capacity of a mechanical press to achieve low production cost and thus high productivity.


Author(s):  
Vahid Bahrami ◽  
Ahmad Kalhor ◽  
Mehdi Tale Masouleh

This study intends to investigate a dynamic modeling and design of controller for a planar serial chain, performing 2-DoF, in interaction with a cable-driven robot. The under study system can be used as a rehabilitation setup which is helpful for those with arm disability. The latter goal can be achieved by applying the positive tensions of the cable-driven robot which are designed based on feedback linearization approach. To this end, the system dynamics formulation is developed using Lagrange approach and then the so-called Wrench-Closure Workspace (WCW) analysis is performed. Moreover, in the feedback linearization approach, the PD and PID controllers are used as auxiliary controllers input and the stability of the system is guaranteed as a whole. From the simulation results it follows that, in the presence of bounded disturbance based on Roots Mean Square Error (RMSE) criteria, the PID controller has better performance and tracking error of the 2-DoF robot joints are improved 15.29% and 24.32%, respectively.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Marshal Thakran ◽  
Meenakshi ◽  
Jitender Sharma ◽  
Charles Gilbert Martin

Purpose The purpose of this paper is to evaluate the model of a rear pressure bulkhead with different design optimizations to meet the pressurized cabin requirements of an aircraft. Design/methodology/approach This paper presents the results of the static analysis of a dome-shaped rear pressure bulkhead model designed in Catia-v5. Numerical analysis of model meshed in hyper-mesh and solved using Opti-Struct for iterative design optimizations. Findings All the iterative models are analyzed at 9 Psi. Rear pressure bulkhead designed with L-section stringer shows better results than the model optimized with T-section stringer for the same thickness. The model optimized with L-shaped stinger also reduces the weight of the bulkhead without affecting the structural integrity. Practical implications It has been concluded in this paper that the selection of specific shapes of the stringers shows a significant influence on weight reduction. Originality/value This paper provides a topical, technical insight into the design and development of a rear pressure bulkhead. It also outlines the future development of dome-shaped rear pressure bulkhead.


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