scholarly journals Estimation and Control for Industrial Products Reliability under Failure Trials

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Kui Wang ◽  
Lili Ding
Keyword(s):  
Confidence Interval ◽  
Control Method ◽  
Reliability Estimation ◽  
Point Estimate ◽  
Industrial Products ◽  
Dynamic Reliability ◽  
Control Approach ◽  
The Status ◽  
Estimation And Control ◽  
And Control

In practices, most industrial products are subject to sudden failure and only failure information can be collected, which presents a great challenge for reliability prediction of modern devices. To address this issue, our paper proposes a dynamic reliability estimation and control for industrial products under regular failure trials. The failure trial is performed at different operational time points of the products, which provides sole data source for evaluating the status of industrial products. We use Bayesian approach to dynamically estimate the industrial products when the failure trial is available. The estimated reliability is updated using a point estimate with new available data. To maintain the reliability of products at a desirable status, a reliability control method is presented to monitor the confidence interval of reliability distribution. The lower limit of confidence interval is maintained above a control limit, which indicates that a corresponding quality-assurance action is preferable. The proposed reliability estimation and control approach is demonstrated using a case of light-emitting diodes under failure trials at production process. The obtained results indicate the effectiveness of our estimation and control model.

scholarly journals Modeling and control of a new robotic deburring system

Robotica ◽  
2005 ◽  
Vol 24 (2) ◽  
pp. 229-237 ◽  
Author(s):  
Jae H. Chung ◽  
Changhoon Kim
Keyword(s):  
Comparative Study ◽  
Decentralized Control ◽  
Control Method ◽  
Robotic Manipulator ◽  
Coordination Control ◽  
Pneumatic Actuators ◽  
Modeling And Control ◽  
Control Approach ◽  
Simulation Results ◽  
And Control

This paper discusses the modeling and control of a robotic manipulator with a new deburring tool, which integrates two pneumatic actuators to take advantage of a double cutting action. A coordination control method is developed by decomposing the robotic deburring system into two subsystems; the arm and the deburring tool. A decentralized control approach is pursued, in which suitable controllers were designed for the two subsystems in the coordination scheme. In simulation, three different tool configurations are considered: rigid, single pneumatic and integrated pneumatic tools. A comparative study is performed to investigate the deburring performance of the deburring arm with the different tools. Simulation results show that the developed robotic deburring system significantly improves the accuracy of the deburring operation.

Intelligent Motion Planning and Control for Robotic Joints Using Bio-Inspired Spiking Neural Networks

2019 ◽  
Vol 16 (04) ◽  
pp. 1950012 ◽  
Author(s):  
Mircea Hulea ◽  
Adrian Burlacu ◽  
Constantin-Florin Caruntu
Keyword(s):  
Neural Network ◽  
Neural Networks ◽  
Motion Planning ◽  
Control Method ◽  
Inhibitory Neurons ◽  
Robotic Arm ◽  
Control Approach ◽  
Planning And Control ◽  
Robotic Joints ◽  
And Control

This paper details an intelligent motion planning and control approach for a one-degree of freedom joint of a robotic arm that can be used to implement anthropomorphic robotic hands. This intelligent control method is based on bio-inspired electronic neural networks and contractile artificial muscles implemented with shape memory alloy (SMA) actuators. The spiking neural network (SNN) includes several excitatory neurons that naturally determine the contraction force of the actuators, and unevenly distributed inhibitory neurons that regulate the excitatory activity. To validate the proposed concept, the experiments highlight the motion planning and control of a single-joint robotic arm. The results show that the electronic neural network is able to intelligently activate motion and hold with high precision the mobile link to the target positions even if the arm is slightly loaded. These results are encouraging for the development of improved biologically plausible neural structures that are able to control simultaneously multiple muscles.

Modeling and control of a mobile manipulator

Robotica ◽  
1998 ◽  
Vol 16 (6) ◽  
pp. 607-613 ◽  
Author(s):  
J. H. Chung ◽  
S. A. Velinsky
Keyword(s):  
Dynamic Model ◽  
Control Method ◽  
Harmful Effect ◽  
Euler Method ◽  
Friction Model ◽  
Mobile Manipulator ◽  
Wheel Slip ◽  
Modeling And Control ◽  
Control Approach ◽  
And Control

This paper concerns the modeling and control of a mobile manipulator which consists of a robotic arm mounted upon a mobile platform. The equations of motion are derived using the Lagrange-d'Alembert formulation for the nonholonomic model of the mobile manipulator. The dynamic model which considers slip of the platform's tires is developed using the Newton-Euler method and incorporates Dugoff's tire friction model. Then, the tracking problem is investigated by using a well known nonlinear control method for the nonholonomic model. The adverse effect of the wheel slip on the tracking of commanded motion is discussed in the simulation. For the dynamic model, a variable structure control approach is employed to minimize the harmful effect of the wheel slip on the tracking performance. The simulation results demonstrate the effectiveness of the proposed control algorithm.

Dynamics and Control of a Helicopter Carrying a Payload Using a Cable-Suspended Robot

2005 ◽  
Author(s):  
So-Ryeok Oh ◽  
Ji-Chul Ryu ◽  
Sunil K. Agrawal
Keyword(s):  
Control Method ◽  
Dual System ◽  
Robust Controller ◽  
Robot System ◽  
Control Approach ◽  
Cable Robot ◽  
Dynamics And Control ◽  
Position And Orientation ◽  
And Control ◽  
Scale Control

This paper presents a study of the dynamics and control of a helicopter carrying a payload through a cable-suspended robot. The helicopter can perform gross motion, while the cable suspended robot underneath the helicopter can modulate a platform in position and orientation. Due to the under-actuated nature of the helicopter, the operation of this dual system consisting of the helicopter and the cable robot is challenging. We propose here a two time scale control method, which makes it possible to control the helicopter and the cable robot independently. In addition, this method provides an effective estimation on the bound of the motion of the helicopter. Therefore, even in the case where the helicopter motion is unknown, the cable robot can be stabilized by implementing a robust controller. Simulation results of the dual system show that the proposed control approach is effective for such a helicopter-robot system.

scholarly journals Childhood Overnutrition among School Going Children in a Municipality: A Descriptive Cross-sectional Study

2021 ◽  
Vol 59 (242) ◽  
pp. 868-871
Author(s):  
Alisha Thapa ◽  
Susmita Nepal ◽  
Garima Malla ◽  
Sushma Pokhrel
Keyword(s):  
Confidence Interval ◽  
School Children ◽  
Binary Data ◽  
Simple Random Sampling ◽  
Cross Sectional Study ◽  
Overweight And Obesity ◽  
Point Estimate ◽  
Sectional Study ◽  
Cross Sectional ◽  
The Status

 Introduction: Childhood obesity, caused due to excessive fat accumulation, is one of the leading causes of preventable deaths associated with several non-communicable diseases. In Nepal, there is limited data available on the status of overweight and obesity among school children. The objective of this study was to find out the prevalence of childhood overnutrition among school going children in a municipality. Methods: A descriptive cross-sectional study was conducted from June 2019 to July 2019, in four schools of a municipality selected by simple random sampling. Ethical approval was obtained from Nepal Health Research Council (Registration number 380/2019). Data was collected using census sampling from children aged 5-18 years through self-administered questionnaires to the children’s parents. The data was entered into the Statistical Package for Social Sciences for analysis. Point estimate at 95% confidence interval was calculated along with frequency and proportion for binary data. Results: Out of 379 school children, the prevalence of overnutrition was found to be 38 (10.03%) (95% Confidence Interval= 7.01-13.05). Prevalence of overnutrition was highest in children of age group 10-13 years 23 (60.5%), in females 27 (71.1%), those consuming junk food 4-6 times weekly 14 (36.8%) and those performing daily physical activity less than 60 minutes 24 (63.2%). Conclusions: The prevalence of childhood overnutrition is similar in comparison to other studies done in similar settings.

Strongly consistent estimation in a controlled Markov renewal model

1982 ◽  
Vol 19 (03) ◽  
pp. 532-545 ◽  
Author(s):  
Michael Kolonko
Keyword(s):  
Optimal Control ◽  
Dynamic Models ◽  
Consistent Estimation ◽  
Unknown Parameters ◽  
Control Approach ◽  
Renewal Model ◽  
Countable State ◽  
Estimation And Control ◽  
And Control ◽  
Strongly Consistent

The optimal control of dynamic models which are not completely known to the controller often requires some kind of estimation of the unknown parameters. We present conditions under which a minimum contrast estimator will be strongly consistent independently of the control used. This kind of estimator is appropriate for the adaptive or ‘estimation and control' approach in dynamic programming under uncertainty. We consider a countable-state Markov renewal model and we impose bounding and recurrence conditions of the so-called Liapunov type.

An Improved Control Method to Solve Thin System Problem

2013 ◽  
Vol 791-793 ◽  
pp. 807-812
Author(s):  
Chun Yang Fu ◽  
Qi Wang
Keyword(s):  
Control Problem ◽  
Control Method ◽  
New Method ◽  
Output Variable ◽  
Control Approach ◽  
Loop Method ◽  
Input Variables ◽  
Square Systems ◽  
And Control

Recently, research of non-square systems mainly focuses on fat system, and control approach to thin systems is less. This paper proposes a new method using improved selection control to square the systems and then design IMC controller for thin systems in which the number of output variables exceeds the number of input variables. This proposed method is applied to the control problem in which there is an output variable that is barely impact on the system. Then we use PSO method to seek the parameters. Then we can come to a conclusion that this method has better performance to reducing loop method through simulation. Moreover, this new method is simple and easy to implement.

scholarly journals Prevalence of Hypertension in a Community

2020 ◽  
Vol 58 (232) ◽  
Author(s):  
Pradeep Paudel ◽  
Samir Chalise ◽  
Dinesh Raj Neupane ◽  
Narayan Adhikari ◽  
Shishir Paudel ◽  
...  
Keyword(s):  
Confidence Interval ◽  
Binary Data ◽  
Adult Population ◽  
Family Members ◽  
Simple Random Sampling ◽  
Primary Data ◽  
Point Estimate ◽  
Cross Sectional ◽  
Hypertensive Patients ◽  
And Control

Introduction: Hypertension is one of the leading risk factors for the global burden of disease and is of rising public health concerns in the developing world including Nepal. However, few studies have focused on awareness, treatment, and control of hypertension among people living with this condition. In this scenario, this study aimed to find out the prevalence of hypertension and its awareness, treatment, and control among hypertensive patients residing in different parts of Kaski district, Nepal. Methods: A descriptive cross-sectional study was performed among 977 family members of 290 households from August to December 2017. Ethical approval was taken from the Institutional Review Committee (reference number:73/074/75) of the Pokhara University Research Center. Simple random sampling was done. Hypertension screening was performed through averaging three values obtained by standardized aneroid sphygmomanometer in three observations. Primary data was collected through self-administered questionnaires and face-to-face interviews based on the participant’s preferences. Collected data were analyzed using Statistical Package for the Social Sciences version 20. Point estimate at 95% Confidence Interval was calculated along with frequency and proportion for binary data. Results: Out Of total 997 family members screened, 294 (29.49%) (26.66-32.32 at 95% confidence interval) had hypertension whereas only 127 (43.2%) were completely aware of their disease condition. 279 (94.9%) were taking antihypertensive medication and 201 (68.4%) had their blood pressure controlled. Conclusions: We found that almost one-fourth of the adult population in the community suffered from hypertension but less than half of the hypertensive patients are aware of their conditions.

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