scholarly journals Selection of Fuzzy Controller Membership Functions Based on Adaptive Gaussian Cloud Transform

2018 ◽  
Vol 36 (3) ◽  
pp. 439-447
Author(s):  
Yong Wang ◽  
Cong Li ◽  
Hanqiao Huang ◽  
Huan Zhou
Keyword(s):  
Fuzzy Controller ◽  
Membership Functions ◽  
Threshold Values ◽  
Coverage Area ◽  
Concept Hierarchy ◽  
Response Characteristics ◽  
Sample Data ◽  
Cloud Transform ◽  
Six Degree Of Freedom ◽  
Selection Of

Aiming at the boundedness of existing methods of selecting membership functions, an adaptive Gaussian cloud transform algorithm which is guided by the threshold values of hybridization degree is proposed to construct concept hierarchy from original sample data, and then the number, shape and coverage area of membership functions can be derived from the distribution of Gaussian cloud. To test and verify the effectiveness of membership function that is extracted based on adaptive Gaussian cloud transform algorithm, a six-degree-of freedom model of unmanned aerial vehicles(UAV) is constructed, and a fuzzy controller of pitching angle is established with the platform of Simulink. The simulation results show that the fuzzy controller which includes membership functions derived from the distribution of Gaussian cloud transform can achieve perfect control performance of pitching angle and meanwhile obtain good dynamic response characteristics.

Matching area selection of an underwater terrain navigation database with fuzzy multi-attribute decision making method

2018 ◽  
Vol 233 (4) ◽  
pp. 1133-1140 ◽  
Author(s):  
Lihui Wang ◽  
Desheng Sun ◽  
Qingya Liu ◽  
Le Yu
Keyword(s):  
Set Theory ◽  
Membership Functions ◽  
Vague Set ◽  
Topographic Factor ◽  
Vague Sets ◽  
Multi Attribute Decision Making ◽  
Matching Performance ◽  
Simulation Results ◽  
Terrain Matching ◽  
Selection Of

Selecting suitable underwater terrain navigation matching areas is a prerequisite for building an underwater terrain navigation database, which is important for vehicles operating underwater. By using information features to evaluate underwater terrain matching areas, vague sets are proposed to evaluate matching performance. Mathematical models of matching area features are built and topographic factor eigenvalues are obtained. With the topographic factor eigenvalues, fuzzy relationships between factor sets and judge sets are calculated. Vague set uses membership functions and non-membership functions to define the influence of topographic factor eigenvalues on matching suitability. Simulation results demonstrate that vague set theory can overcome the deficiency of single value in fuzzy sets and define the effect of geographic characteristics for matching performance. Based on vague set method, selection rules for terrain navigation matching areas in underwater terrain database are put forward.

Fuzzy Logic Controller for Obstacle Avoidance of Mobile Robot

2019 ◽  
Vol 20 (1) ◽  
pp. 51-62
Author(s):  
Rajmeet Singh ◽  
Tarun Kumar Bera
Keyword(s):  
Fuzzy Logic ◽  
Mobile Robot ◽  
Dynamic Model ◽  
Obstacle Avoidance ◽  
Fuzzy Logic Controller ◽  
Fuzzy Controller ◽  
Bond Graph ◽  
Membership Functions ◽  
Current Position ◽  
Dc Motors

AbstractThis work describes design and implementation of a navigation and obstacle avoidance controller using fuzzy logic for four-wheel mobile robot. The main contribution of this paper can be summarized in the fact that single fuzzy logic controller can be used for navigation as well as obstacle avoidance (static, dynamic and both) for dynamic model of four-wheel mobile robot. The bond graph is used to develop the dynamic model of mobile robot and then it is converted into SIMULINK block by using ‘S-function’ directly from SYMBOLS Shakti bond graph software library. The four-wheel mobile robot used in this work is equipped with DC motors, three ultrasonic sensors to measure the distance from the obstacles and optical encoders to provide the current position and speed. The three input membership functions (distance from target, angle and distance from obstacles) and two output membership functions (left wheel voltage and right wheel voltage) are considered in fuzzy logic controller. One hundred and sixty-two sets of rules are considered for motion control of the mobile robot. The different case studies are considered and are simulated using MATLAB-SIMULINK software platform to evaluate the performance of the controller. Simulation results show the performances of the navigation and obstacle avoidance fuzzy controller in terms of minimum travelled path for various cases.

Servo respirator constructed from a positive-pressure ventilator

1976 ◽  
Vol 41 (2) ◽  
pp. 252-255 ◽  
Author(s):  
J. E. Remmers ◽  
H. Gautier
Keyword(s):  
Negative Feedback ◽  
Differential Amplifier ◽  
Positive Pressure ◽  
Precise Control ◽  
Pressure Signal ◽  
Response Characteristics ◽  
Tracheal Pressure ◽  
Selection Of

We have constructed an electronically controlled respirator from three commercially available components: a positive-pressure ventilator, a recorder pen motor, and a differential amplifier. Using negative feedback derived from a tracheal pressure signal, the instrument functions as a servo respirator which provides precise control of tracheal pressure. The system's power and response characteristics are well suited for ventilation of anesthetized cats and dogs. The servo respirator can be used as an externallycontrolled respiratory pump which provides flexibility in selection of the parameters of the ventilatory cycle. Alternatively, it can function as a “demand” respirator which generates transthoracic pressure proportional to efferent respiratory discharge.

MODELING THE SYNTHESIS OF TAKAGI — SUGENO — KANG FUZZY CONTROLLERS IN SOME CONTROL SYSTEMS

2021 ◽  
Vol 7 (2) ◽  
pp. 147-169
Author(s):  
Irina V. Kulikova
Keyword(s):  
Genetic Algorithms ◽  
Control System ◽  
Fuzzy Controller ◽  
Industrial Society ◽  
Control Action ◽  
Effective Control ◽  
Control Parameters ◽  
Membership Functions ◽  
Fuzzy Controllers ◽  
Takagi Sugeno

Modern challenges in a post-industrial society require further development of management systems for complex technical and technological phenomena and processes. Effective control of an object is possible if a controller, or a fuzzy controller, correctly generates the required control action. Recently, fuzzy controllers have been very popular. Fuzzy logical statements in this case help considering various nonlinear relationships. The synthesis of the fuzzy controller parameters allows for more efficient operation of the control system. A possible option for obtaining the best set of parameters for a fuzzy controller is the use of genetic algorithms for its synthesis. The use of genetic algorithms for the fuzzy controllers synthesis can lead to the fact that the elements of its parameters array will change in such a way that an incorrect value of one or more elements will occur. This situation leads to impossibility of composing membership functions for the terms of the variables of the fuzzy controller. Incorrect value formation is excluded by constructing a limited functional dependency. This paper proposes a mathematical model of the parameters of the term-set of variables of a fuzzy controller of the Takagi — Sugeno — Kang type of the zero and first orders. The authors disclose the content of the conditions and conclusions of the rule base for the fuzzy controller of the above type. As a result of the simulation, some operations of the genetic algorithm are implemented using a random number generator. Graphical models of the membership functions of the input variables of the fuzzy controller of the type under consideration clearly illustrate the occurrence of all parameters in their range of possible values. A description of the control system operation with two control parameters and one control action at the specified values of the control parameters is presented.

Fading Activities of Herbicidal Droplets Amended with Emulsifiable Spray Adjuvants on Cucurbitaceous Leaves

2018 ◽  
Vol 61 (6) ◽  
pp. 1881-1888
Author(s):  
Jeng-Liang Lin ◽  
Heping Zhu
Keyword(s):  
Weed Control ◽  
Droplet Size ◽  
Spray Deposition ◽  
Herbicide Application ◽  
Spray Droplet ◽  
Coverage Area ◽  
Maximum Coverage ◽  
Fading Time ◽  
Selection Of ◽  
Spray Adjuvants

Abstract. Understanding reactions of surfactant-amended droplets on difficult-to-wet weed surfaces could help develop application strategies to increase herbicide efficacy. Behaviors of herbicidal droplets containing different emulsifiable anti-evaporation spray adjuvants were investigated by characterizing 250 and 450 µm herbicidal droplet dispersion and fading time on cucurbitaceous leaves placed inside a 20°C chamber at 30% and 60% relative humidity (RH). Droplet maximum coverage area increased with droplet size but not with RH, while droplet fading time increased with both droplet size and RH. Despite 450 µm droplets having greater maximum coverage area than 250 µm droplets, the larger droplets had higher fading rates and lower ratios of maximum coverage area to droplet volume. Droplet maximum coverage area and fading time on leaves were affected by adding spray adjuvants to the herbicide-only solution. The Uptake surfactant was more effective than the other two surfactants (AntiEvap+BS1000 and Enhance) in increasing droplet maximum coverage area and fading time. Compared to the herbicide-only solution, addition of Uptake surfactant to the herbicide solution could increase maximum coverage area by 68% and 52% for 250 and 450 µm droplets, respectively, but addition of AntiEvap+BS1000 or Enhance surfactants did not show significant increase. Similarly, addition of Uptake surfactant to the herbicide-only solution increased droplet fading times by 11.1% and 13.2% at 30% and 60% RH, respectively, for 250 µm droplets and by 34.7% and 2.8% at 30% and 60% RH, respectively, for 450 µm droplets. In contrast, addition of AntiEvap+BS1000 surfactant reduced fading time, and addition of Enhance surfactant did not significantly affect fading time. Therefore, appropriate selection of spray adjuvants for herbicide applications could significantly influence droplet deposit behaviors on cucurbitaceous leaves, leading to improved effectiveness of weed control. Keywords: Herbicide application, Spray deposition, Spray droplet, Surfactant, Weed control.

scholarly journals The discursive production of professionals about humanizing health: singularity, rights and ethics

2015 ◽  
Vol 23 (5) ◽  
pp. 936-944 ◽  
Author(s):  
Rose Mary Costa Rosa Andrade Silva ◽  
Denize Cristina de Oliveira ◽  
Eliane Ramos Pereira
Keyword(s):  
Quality Care ◽  
Social Representation ◽  
University Hospital ◽  
The Social ◽  
Sample Data ◽  
Social Representation Theory ◽  
Provide Quality Care ◽  
Descriptive Approach ◽  
Historical Scenario ◽  
Selection Of

Objective: to describe the discursive production of professionals about the humanization of health.Method: qualitative study of descriptive approach, inspired by the social representation theory, with 24 professionals in the healthcare field, working in a university hospital with the established humanization policy. The selection of participants was conducted according to criteria of adequacy and diversity for an intentional sample. Data collection was conducted by semi-structured interviews.Results: through content analysis, three categories emerged, around which the analyses were conducted: "humanizing health as an act of accepting the other as unique", "humanizing health as a matter of right" and "humanizing health as an ethical issue". The discursive production of professionals is based on a perspective which is based on the humanist prospect with socio-historical bias.Conclusion: healthcare professionals must know the National Humanization Policy in order to provide quality care, promoting the meeting, welcoming and recognition of oneself, others and their profession in the political and socio-historical scenario of their country as a citizen, not only of rights, but also of obligations.

The Arc Sound Characteristic on MIG Weld Penetration

2010 ◽  
Vol 97-101 ◽  
pp. 3948-3951 ◽  
Author(s):  
Li Jun Liu ◽  
Lan Hu
Keyword(s):  
Welding Process ◽  
Sound Signal ◽  
Weld Penetration ◽  
Time Frequency ◽  
Sample Data ◽  
On Line ◽  
The Relationship ◽  
Arc Sound ◽  
Arc Sound Signal ◽  
Selection Of

Arc sound signal in MIG welding contains plenty of welding information, which is an important signal source of weld penetration. Aiming at on-line monitoring of weld penetration, the relationship between arc sound signal and penetration is analyzed in time-frequency domain through a reasonable selection of sample data. The results show that the spectrum of arc sound signal and penetration status are highly correlative. The changes of penetration can accurately detected by variation of signal energy from 1500 Hz to 4500 Hz in welding process. The above experiments verify the feasibility of monitoring the penetration through arc sound signal and provides theory and application foundation for penetration adaptive control.

Research of the System Based on BP Network for the Prediction of Grape Disease

2013 ◽  
Vol 462-463 ◽  
pp. 476-480
Author(s):  
Feng Bao ◽  
Juan Wang ◽  
Zhen Hui Ren
Keyword(s):  
Influencing Factors ◽  
Network Model ◽  
Network Structure ◽  
Good Effect ◽  
Bp Network ◽  
Disease Occurrence ◽  
Sample Data ◽  
Long Term Prediction ◽  
Selection Of

The text introduced a system based on BP network for the prediction of grape disease. It included the design of a network structure, the selection of parameter for network study, the processing of sample data etc. With the use of BP network model, this system can forecast the extent of grape disease, so it is applicable to the conditions which have many influencing factors, complicated relationship, difficulty of analyze quantitatively and requirement of long-term prediction. Using this system to the prediction of grape disease in Zhuo Lu area Zhang Jia Kou city, the authors obtained a good effect, which is of value to the prediction of grape disease occurrence.

Optimal selection of the supporting points of large component aligned and positioned by parallel manipulator

2016 ◽  
Vol 230 (17) ◽  
pp. 3066-3075
Author(s):  
Hongshuang Zhang ◽  
Junxia Jiang ◽  
Yinglin Ke ◽  
Qing Wang
Keyword(s):  
Parallel Manipulator ◽  
Stability Index ◽  
Stiffness Index ◽  
Performance Indices ◽  
Large Component ◽  
Global Performance ◽  
Effective Selection ◽  
Capacity Index ◽  
Six Degree Of Freedom ◽  
Selection Of

Large components such as wing sections should be aligned and positioned in a desired position prior to the final manufacturing or assembly, so a digital alignment and position device based on six degree of freedom parallel manipulator with several prismatic-prismatic-prismatic-spherical branches was designed and fabricated to meet the needs. The digital alignment and position device is an alignment device based on the parallel manipulator, and it is also a positioning and holding fixture for large components manufacturing or assembly. In order to effectively and efficiently select the supporting points of large component where the digital alignment and position device branch is connected with, the performance of the parallel manipulator and the fixture should be comprehensively analyzed at the same time. The global performance indices such as the dexterity index, the bearing capacity index, and the stiffness index are calculated based on the mechanism Jacobean matrix of the parallel manipulator, and the positioning stability index is calculated based on the position Jacobean matrix of the fixture. The results show that the global performance indices are not related to the pose, but the positioning stability index is; in addition, all indices rely on the originally selected supporting points and provide the basis for the effective selection of the supporting points for large component aligned and positioned by the digital alignment and position device, which is based on parallel manipulator with prismatic- prismatic-prismatic-spherical pairs.

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