cost function
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Energies ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 419
Author(s):  
Piotr Derugo ◽  
Krzysztof Szabat ◽  
Tomasz Pajchrowski ◽  
Krzysztof Zawirski

This paper presents original concepts of control systems for an electrical drive with an elastic mechanical coupling between the motor and the driven mechanism. The synthesis procedure of the speed controller uses a proposed quality index (cost function) of system operation ensures the minimization of both tracking errors and torsional vibrations. Proper selection of the cost function focusses more on the reduction of torsional vibrations due to their negative influence on the drive’s mechanical coupling vitality. The omission of the plant identification of an adaptive fuzzy controller was proposed. Two types of fuzzy controllers were analyzed, namely with type I and type II fuzzy membership functions. The novelty of the presented approach is in the application of a Petri transition layer in a type II fuzzy controller which reduces the numerical complexity in case of a large number of complicated type II fuzzy sets. The presented simulation and experimental results prove that the best dumping of mechanical vibrations ensures the adaptive fuzzy controller with type II functions and a Petri transition layer.


Author(s):  
Zhicheng Shi ◽  
Cheng Zhang ◽  
Du Ran ◽  
Yan Xia ◽  
Reuven Ianconescu ◽  
...  

Abstract In this work, we propose a composite pulses scheme by modulating phases to achieve high fidelity population transfer in three-level systems. To circumvent the obstacle that not enough variables are exploited to eliminate the systematic errors in the transition probability, we put forward a cost function to find the optimal value. The cost function is independently constructed either in ensuring an accurate population of the target state, or in suppressing the population of the leakage state, or both of them. The results demonstrate that population transfer is implemented with high fidelity even when existing the deviations in the coupling coefficients. Furthermore, our composite pulses scheme can be extensible to arbitrarily long pulse sequences. As an example, we employ the composite pulses sequence for achieving the three-atom singlet state in an atom-cavity system with ultrahigh fidelity. The final singlet state shows robustness against deviations and is not seriously affected by waveform distortions. Also, the singlet state maintains a high fidelity under the decoherence environment.


2022 ◽  
Vol 11 (1) ◽  
pp. [12 P]-[12 P]
Author(s):  
María Aracelia Alcorta García ◽  
SANTOS MENDEZ DIAZ ◽  
JOSE ARMANDO SAENZ ESQUEDA ◽  
GERARDO MAXIMILIANO MENDEZ DIAZ ◽  
NORA ELIZONDO VILLAREAL ◽  
...  

This work presents an application of the Risk-Sensitive (R-S) control with tracking applied to a stochastic nonlinear system which models the operation of an electronic expansion valve (EEV) in a conventional evaporator. A novel dynamical stochastic equation represents the mathematical model of the evaporator system. The R-S stochastic optimal problem consists of the design of an optimal control u(t) such that the state reaches setpoint values (SP) and minimizes the exponential quadratic cost function. The presence of disturbances and errors in the sensor measurements is represented by Gauss white noise in the state equation, with the coefficient v(e/(2?^2 )) . One novel characteristic in this proposal is that the coefficient of the control into the state equation contains the state term. The error and exponential quadratic cost function show that the R-S control has a better performance versus the classical PID (Proportional, Integral Derivative) control. Key Words: Optimal Risk-Sensitive control with tracking, modelling of the evaporator.


2022 ◽  
Vol 26 (1) ◽  
pp. 43-54
Author(s):  
Ahmed J. Abdulqader ◽  
◽  
Raad H. Thaher ◽  
Jafar R. Mohammed ◽  
◽  
...  

In practice, random errors in the excitations (amplitude and phase) of array elements cause undesired variations in the array patterns. In this paper, the clustered array elements with tapered amplitude excitations technique are introduced to reduce the impact of random weight errors and recover the desired patterns. The most beneficial feature of the suggested method is that it can be used in the design stage to count for any amplitude errors instantly. The cost function of the optimizer used is restricted to avoid any unwanted rises in sidelobe levels caused by unexpected perturbation errors. Furthermore, errors on element amplitude excitations are assumed to occur either randomly or sectionally (i.e., an error affecting only a subset of the array elements) through the entire array aperture. The validity of the proposed approach is entirely supported by simulation studies.


Author(s):  
Nguyen Huu Quang ◽  
Tran Thi Phuong Thao ◽  
Tran Quoc Hoang ◽  
Trinh Kieu Tuan ◽  
Nguyen Dinh Ngoc ◽  
...  
Keyword(s):  

Author(s):  
Yuan-Shyi P. Chiu ◽  
Jian-Hua Lian ◽  
Victoria Chiu ◽  
Yunsen Wang ◽  
Hsiao-Chun Wu

Manufacturing firms operating in today’s competitive global markets must continuously find the appropriate manufacturing scheme and strategies to effectively meet customer needs for various types of quality of merchandise under the constraints of short order lead-time and limited in-house capacity. Inspired by the offering of a decision-making model to aid smooth manufacturers’ operations, this study builds an analytical model to expose the influence of the outsourcing of common parts, postponement policies, overtime options, and random scrapped items on the optimal replenishment decision and various crucial system performance indices of the multiproduct problem. A two-stage fabrication scheme is presented to handle the products’ commonality and the uptime-reduced strategies to satisfy the short amount of time before the due dates of customers’ orders. A screening process helps identify and remove faulty items to ensure the finished lot’s anticipated quality. Mathematical derivation assists us in finding the manufacturing relevant total cost function. The differential calculus helps optimize the cost function and determine the optimal stock-replenishing rotation cycle policy. Lastly, a simulated numerical illustration helps validate our research result’s applicability and demonstrate the model’s capability to disclose the crucial managerial insights and facilitate manufacturing-relevant decision making.


Author(s):  
Nguyen Hong Linh ◽  
Tran Thi Phuong Thao ◽  
Dang Quoc Cuong ◽  
Trinh Kieu Tuan ◽  
Le Hoang Anh ◽  
...  
Keyword(s):  

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