selection principle
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Author(s):  
Mehmet Çinar

Control strategies for uncertainties or nonlinear effects need to be developed for control systems. Optimization algorithms developed with the rapid development of computer technology are frequently used to improve the steady-state response with the help of the ambiguous mathematical characteristics or nonlinearity of control systems. In this study, an optimum proportional–integral–derivative (PID) controller was designed using the wound healing algorithm based on the clonal selection principle. The proposed algorithm is applied in self-tuning a PID controller in the ball and hoop system which represents a system of complex industrial processes. In order to adjust the PID parameters with the aid of the developed algorithm, an integral absolute error (IAE) has been chosen as the objective function. Thus, the system reached the optimum solution quickly and time was saved. The advantages of the proposed algorithm have been proved by comparing the obtained results with other algorithms. To succeed this, a programme was written in the MATLAB GUI environment.


Author(s):  
Mehmet Çinar ◽  

Fractional-order PID (FOPID) controller is a generalization of standard PID controller using fractional calculus. Compared to PID controller, the tuning of FOPID is more complex and remains a challenge problem. This paper focuses on the design of FOPID controller using wound healing algorithm (WHA) based on clonal selection principle. The tuning of FOPID controller is formulated as a nonlinear optimization problem, in which the objective function is composed of overshoot, steady-state error, raising time and settling time. WHA algorithm, a newly developed evolutionary algorithm inspired by human immune system, is used as the optimizer to search the best parameters of FOPID controller. The designed WHA-FOPID controller is applied to various systems. Numerous numerical simulations and comparisons with other FOPID/PID controllers show that the WHA-FOPID controller can not only ensure good control performance with respect to reference input but also improve the system robustness with respect to model uncertainties.


2021 ◽  
Vol 16 (4) ◽  
pp. 359-372
Author(s):  
Lin-Shu Wang

The entropy principle has been commonly considered to be a selection principle. A history/philosophy-of-science analysis of development in thermodynamic thought was carried out based on a historical account of contributions to thermodynamics of nine Schools of thermodynamics plus that of Mayer/Joule (the Mayer-Joule principle), publication of A Treatise of Heat and Energy, development in maximum entropy production principle (MEPP), and process ecology formulated by Ulanowicz. The analysis discloses the dual nature in the entropy principle, as selection principle and causal principle, and that as well in thermodynamics: as equilibrium thermodynamics (Gibbsian thermodynamics) and as “engineering” thermodynamics in a general sense. Entropy-growth-potential (EGP) as the causal agent and the theory of engineering thermodynamics entail the concept of causal necessity, as suggested by Poincare. Recent development of the entropy principle into maximum entropy production principle (MEPP) is then critically analyzed. Special attention is paid to MEPP’s explanatory power of biological orders vs. that of process ecology: whereas MEPP asserts universal approach to physics and biology based on physical necessity and efficient causation, the case for “EGP as the causal agent and process ecology” allows biology to be different from physics by allowing the additional presupposition of causal necessity and efficacious causation.


2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Yajun Chen ◽  
Yongbin Li ◽  
Dong Yang ◽  
Tiejun Li

When the two arms of the robot are transporting the heavy loads together, a new parallel mechanism is formed. The actuator input selection and optimization of the parallel mechanism are basic and important problems in mechanism research. In this paper, a 2-RPPPS dual-arm robot is taken as the research object. Firstly, based on the screw theory and input selection principle, 158 reasonable schemes are obtained. Then, an evaluation mechanism is established to screen out the schemes that do not conform to the input selection principle. Then, the end effector of the parallel mechanism moves along two different trajectories. Using the particle swarm optimization algorithm, the inverse kinematics solution of each trajectory is obtained, and the velocity and acceleration of each actuator under different trajectories are obtained. Finally, the motion stability of each actuator is evaluated, and the best scheme is selected. The results show that the best input scheme can be selected according to different trajectories, so as to improve the performance of the parallel mechanism. To the authors’ knowledge, no one has done any research on selecting the appropriate input scheme according to the trajectory of the end effector.


2021 ◽  
pp. 1-11
Author(s):  
Youcheng Han ◽  
Caizhi Zhou ◽  
Weizhong Guo

Abstract This paper presents the reconfigurable legged mobile lander (ReLML) with its modes from adjusting, landing, to roving. Based on the invented metamorphic variable-axis revolute hinge, the actuated link has three alternative phases of rotating around either of two orthogonal topological axes or locking itself to the base as a rigid body. This property enables the ReLML to switch among three modes and within two driving states (as the adjusting and roving modes are active mechanisms driven by motors, while the landing truss is regarded as a passive mechanism driven by the touchdown impact force exerted on footpad). The unified differential kinematics for the ReLML is established by the screw-based Jacobian modeling, unifying both active and passive operation phases throughout all modes. Afterward, the distributions of workspaces and singularity loci in three modes are discussed for the multi-solution sake, and the selection principle of the practicable solution pattern is proposed to obtain the actual workspace, singularity loci, and configurations. The results stemming from the Jacobian-matrix-based method and the Grassmann-geometry-based method give mutual authentication and match well. Finally, as prospects for promising applications, four bifurcated evolution routes and configuration transitions are figured out and compared.


2021 ◽  
Vol 19 (2) ◽  
pp. 216-228
Author(s):  
Kholidun Asri

The aim of this study is therefore to identify the types of problemsof teachers in the selection of Arabic mufrodat in Grade VII students ofMadrasah Tsanawiyah Fadllillah. The method used in this research, usingresearch and development methods (R&D) refers to the Thiagarajan 4Dmodel, which focuses on the definition or definition phase, using the RusydiAhmad Thu’aimah mufrodat selection principle, which is divided into sevenmufrodat selection principles. This research was carried out at one of the mostcumbersome educational institutions in the Waru area , at MTs. Fadllillah Jl.Kyai Ali No 57 A Sidoarjo Waru Sidoarjo. The results of this study have ledto the discovery of many of the problems faced by teachers in determininggood, accurate and effective mufrodats to be taught to students. For example,the appropriateness of the principles for the selection of mufrodat accordingto the principle of frequency is the choice of mufrodat in accordance withthe application of everyday language, but there are also principles that arenot appropriate, such as the principle of availability of teachers who do notknow the ability of students to understand words.


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