A study on product assembly and disassembly time prediction methodology based on virtual maintenance

2019 ◽  
Vol 39 (4) ◽  
pp. 566-580 ◽  
Author(s):  
Kaijun Cai ◽  
Weiming Zhang ◽  
Wenzhuo Chen ◽  
Hongfei Zhao
Keyword(s):  
Evaluation Method ◽  
Body Movement ◽  
Influence Factors ◽  
Prediction Method ◽  
Standard Theory ◽  
Content Type ◽  
Time Prediction ◽  
Physical Prototype ◽  
Motion Characteristics ◽  
Virtual Maintenance

Purpose Based on virtual maintenance, this paper aims to propose a time prediction method of assembly and disassembly (A&D) actions of product maintenance process to enhance existing methods’ prediction accuracy, applicability and efficiency. Design/methodology/approach First, a framework of A&D time prediction model is constructed, which describes the time prediction process in detail. Then, basic maintenance motions which can comprise a whole A&D process are classified into five categories: body movement, working posture change, upper limb movement, operation and grasp/placement. A standard posture library is developed based on the classification. Next, according to motion characteristics, different time prediction methods for each motion category are proposed based on virtual maintenance simulation, modular arrangement of predetermined time standard theory and the statistics acquired from motion experiment. Finally, time correction based on the quantitative evaluation method of motion time influence factors is studied so that A&D time could be predicted with more accuracy. Findings Case study of time prediction of products’ various A&D processes is conducted by implementing the proposed method. The prediction process of diesel cooling fan disassemble time is presented in detail. Through comparison, the advantages and effectiveness of the method are demonstrated. Originality/value This paper proposes a more accurate, efficient and applicable product A&D time prediction method. It can help designers predict A&D time of a product maintenance accurately in early design phases without a physical prototype. It can also provide basis for the verification of maintainability, the balance of the design of product structure and system layout.

The method of predicting the maintenance time of mechanical products based on Virtual Prototype

2022 ◽  
Vol 15 ◽  
Author(s):  
Jin Li ◽  
Xinsheng Jiang ◽  
Zituo Wang ◽  
Chunhui Wang ◽  
Yunxiong Cai
Keyword(s):  
Body Movement ◽  
Estimation Method ◽  
Prediction Method ◽  
Virtual Prototype ◽  
Time Prediction ◽  
Maintenance Time ◽  
Mechanical Products ◽  
Physical Prototype ◽  
Virtual Maintenance ◽  
Maintenance Process

Aim: To predict the mechanical product maintenance time is difficult in the situation of lack of physical prototype or similar products’ statistics in stage of design Method: According to the theory of time accumulative estimation method, a product maintenance time prediction method framework based on virtual prototype was constructed, which described the prediction process. The virtual maintenance environment which contains virtual prototype, virtual human and maintenance tools was developed. The virtual human’s position and posture information during the maintenance process was obtained by implementing VBScript language. Result: Basic maintenance motions that constitute the whole maintenance process were classified into 4 categories: body movement, upper limb movement, grasp/replace and operation. Based on MODAPTS (Modular arrangement of predetermined time standard) method and virtual maintenance simulation, corresponding time prediction methods for each categories were proposed. Discussion: Take a maintenance dissassembly and assembly task of engine as an example, through the comparison between the measured actual maintenance time and predicted time of several methods, feasibility and effectiveness of proposed method are verified

scholarly journals Weight Analysis of Influence Factors and Potential Evaluation Method for Chemical Combination Flooding

2018 ◽  
Vol 53 ◽  
pp. 01022
Author(s):  
LIU Zhaoxia ◽  
WANG Qiang ◽  
MA Desheng ◽  
Gaoming ◽  
LIU Wanlu
Keyword(s):  
Evaluation Method ◽  
Influence Factor ◽  
Comprehensive Evaluation ◽  
Influence Factors ◽  
Prediction Method ◽  
Weight Coefficient ◽  
New Method ◽  
Chemical Flooding ◽  
Evaluation Score ◽  
Chemical Combination

In this paper, the weight coefficient of influencing factors for chemical combination flooding is determined by using grey correlation theory. A calculation method for comprehensive evaluation score of chemical combination flooding is established. The influence factor grading and weight grading are combined in this method. By collecting and analysing chemical combination flooding field tests, a prediction method for chemical combination flooding is established by the exponential regression. It reflects the relationship between EOR of the chemical combination flooding and the comprehensive evaluation score. The new method is applied in 6 different reservoirs to evaluate the effect of chemical flooding. The new method determines the weight coefficient of influence factors for chemical combination flooding. It can quickly predict EOR factor of chemical flooding to provide a basis for chemical flooding planning in the field.

Research on configuration design and operation effect evaluation for ultra high voltage (UHV) vertical insulator cleaning robot

2019 ◽  
Vol 47 (1) ◽  
pp. 90-101 ◽  
Author(s):  
Yu Yan ◽  
Wei Jiang ◽  
An Zhang ◽  
Qiao Min Li ◽  
Hong Jun Li ◽  
...  
Keyword(s):  
Neural Network ◽  
Motion Planning ◽  
High Voltage ◽  
Bp Neural Network ◽  
Evaluation Method ◽  
Effect Evaluation ◽  
Content Type ◽  
Network Training ◽  
Cleaning Robot ◽  
Physical Prototype

Purpose This study aims to the three major problems of low cleaning efficiency, high labor intensity and difficult to evaluate the cleaning effect for manual insulators cleaning in ultra high voltage (UHV) converter station, the purpose of this paper is to propose a basic configuration of UHV vertical insulator cleaning robot with multi-freedom-degree mechanical arm system on mobile airborne platform and its innovation cleaning operation motion planning. Design/methodology/approach The main factors affecting the insulators cleaning effect in the operation process have been analyzed. Because of the complex coupling relationship between the influencing factors and the insulators cleaning effect, it is difficult to establish its analytical mathematical model. Combining the non-linear mapping and approximation characteristics of back propagation (BP) neural network, the insulator cleaning effect evaluation can be abstracted as a non-linear approximation process from actual cleaning effect to ideal cleaning effect. An evaluation method of robot insulator cleaning effect based on BP neural network has been proposed. Findings Through the BP neural network training, the robot cleaning control parameters can be obtained and used in the robot online operation control, so that the better cleaning effect can be also obtained. Finally, a physical prototype of UHV vertical insulator cleaning robot has been developed, and the effectiveness and engineering practicability of the proposed robot configuration, cleaning effect evaluation method are all verified by simulation experiments and field operation experiments. At the same time, this method has the remarkable characteristics of sound versatility, strong adaptability, easy expansion and popularization. Originality/value An UHV vertical insulator cleaning robot operation system platform with multi-arm system on airborne platform has been proposed. Through the coordinated movement of the manipulator each joint, the manipulator can be positioned to the insulator strings, and the insulator can be cleaned by two pairs high-pressure nozzles located at the double manipulator. The influence factors of robot insulator cleaning effect have been analyzed. The BP neural network model of insulator cleaning effect evaluation has been established. The evaluation method of robot insulator cleaning effect based on BP neural network has also been proposed, and the corresponding evaluation result can be obtained through the network training. Through the system integration design, the robot physical prototype has been developed. For the evaluation of other operation effects of power system, the validity and engineering practicability of the robot mechanism, motion planning and the method for evaluating the effect of robot insulator cleaning have been verified by simulation and field operation experiments.

Forecasting Model of Short-Term Traffic Flow Based on Cloud Model

2011 ◽  
Vol 94-96 ◽  
pp. 38-42
Author(s):  
Qin Liu ◽  
Jian Min Xu
Keyword(s):  
Real Time ◽  
Traffic Flow ◽  
Cloud Model ◽  
Prediction Method ◽  
Absolute Error ◽  
Short Term ◽  
Guangzhou City ◽  
Time Prediction ◽  
Real Time Traffic ◽  
Absolute Percent Error

In order to improve the prediction precision of the short-term traffic flow, a prediction method of short-term traffic flow based on cloud model was proposed. The traffic flow was fit by cloud model. The history cloud and the present cloud were built by historical traffic flow and present traffic flow. The forecast cloud is produced by both clouds. Then, combining with the volume of the short-term traffic flow of an intersection in Guangzhou City, the model was calculated and simulated through programming. Max Absolute Error (MAE) and Mean Absolute percent Error (MAPE) were used to estimate the effect of prediction. The simulation results indicate that this prediction method is effective and advanced. The change of the historical and real time traffic flow is taken into account in this method. Because the short-term traffic flow is dealt with as a whole, the error of prediction is avoided. The prediction precision and real-time prediction are satisfied.

Study on Prediction of the Peasants’ Income Based on SVM

2014 ◽  
Vol 687-691 ◽  
pp. 5169-5172
Author(s):  
Li Na Zhang ◽  
Bo Yang
Keyword(s):  
Social Factors ◽  
Index System ◽  
Statistical Data ◽  
Influence Factors ◽  
Prediction Method ◽  
Svm Model ◽  
The Index System ◽  
Relationship Of ◽  
System Designs ◽  
Computing Speed

China is a big agricultural country, effective prediction of peasants’ income is very important. This study mainly uses the SVM theory to predict the peasants’ income. By analyzing the influence factors of peasants’ income, establishes the index system, that is corresponding relationship of peasants’ income and factors of social influence, According to this index system, designs the prediction method of peasants’ income based on SVM. Bases on the statistical data of social factors and peasants’ income between 1990-2012 in china, to train the SVM model, at the same time, the kernel function and parameters of SVM used were setting and compared. The experimental results show that the accuracy of RBF function is 90.7%, the time is 98ms, has higher accuracy and faster computing speed.

Who is more likely to become business angels?

2014 ◽  
Vol 6 (1) ◽  
pp. 4-20 ◽  
Author(s):  
Yaokuang Li ◽  
Li Ling ◽  
Juan Wu ◽  
Peng Li
Keyword(s):  
Influence Factors ◽  
Positive Influence ◽  
Clear Understanding ◽  
Logit Analysis ◽  
Business Angels ◽  
Investment Activity ◽  
Content Type ◽  
Angel Investment ◽  
Investment In China ◽  
Practical Implications

Purpose – The paper is aimed to obtain a clear understanding of influence factors that can increase the possibility to be business angels (BA). Design/methodology/approach – This study develops the 3A model in the Chinese context to design questionnaire, and 334 questionnaires are obtained via focus group sample and targeted snowball approach, and the multinomial logit analysis is used to test a serious of hypotheses. Findings – The paper confirmed that the entrepreneurial experience and wealth are determinants of investment for potential BA, and the wealth have both directly and indirectly positive influence on investment activity through risk preference, namely that richer people prefer risk which impel them to invest as BA. Research limitations/implications – There are two limitations in the paper: first, the macro environment in China has not been taken into consideration in the model; second, the source of the sample focuses on the developed cities in the middle and eastern of China, only reflect the characteristic of angels in these areas, which may somewhat diverges from the reality. Practical implications – The paper would contribute to form the policy which could promote the development of angel investment in China. Originality/value – This paper conducts a preliminary exploration of the factors that have impact on Chinese BA' investment activity based on current research.

Design and locomotion analysis of the tetrahedral mobile robot with only revolute joints (TMRR)

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Zhirui Wang ◽  
Yezhuo Li ◽  
Bo Su ◽  
Lei Jiang ◽  
Ziming Zhao ◽  
...  
Keyword(s):  
Mobile Robot ◽  
Main Body ◽  
Dynamics Analysis ◽  
Content Type ◽  
Displacement Error ◽  
Working Space ◽  
Revolute Joints ◽  
Physical Prototype ◽  
Moving Direction ◽  
Rolling Locomotion

Purpose The purpose of this paper is to introduce a tetrahedral mobile robot with only revolute joints (TMRR). By using rotation actuators, the mechanism of the robot gains favorable working space and eliminates the engineering difficulties caused by the multilevel extension compared with liner actuators. Furthermore, the rolling locomotion is improved to reduce displacement error based on dynamics analysis. Design/methodology/approach The main body of deforming mechanism with a tetrahedral exterior shape is composed of four vertexes and six RRR chains. The mobile robot can achieve the rolling locomotion and reach any position on the ground by orderly driving the rotation actuators. The global kinematics of the mobile modes are analyzed. Dynamics analysis of the robot falling process is carried out during the rolling locomotion, and the rolling locomotion is improved by reducing the collision impulse along with the moving direction. Findings Based on global kinematics analysis of TMRR, the robot can realize the continuous mobility based on rolling gait planning. The main cause of robot displacement error and the corresponding improvement locomotion are gained through dynamic analysis. The results of the theoretical analysis are verified by experiments on a physical prototype. Originality/value The work introduced in this paper is a novel exploration of applying the mechanism with only revolute joints to the field of tetrahedral rolling robots. It is also an attempt to use the improved rolling locomotion making this kind of mobile robot more practical. Meanwhile, the reasonable engineering structure of the robot provides feasibility for load carrying.

The effect of body-movement teaching, learning motivation and performance

2016 ◽  
Vol 24 (3) ◽  
pp. 414-437 ◽  
Author(s):  
Satoshi Sugahara ◽  
Hisayo Sugao ◽  
Steven Dellaportas ◽  
Takahiro Masaoka
Keyword(s):  
Body Movement ◽  
Learning Motivation ◽  
Control Group ◽  
Content Type ◽  
Entry Level ◽  
Quasi Experimental ◽  
And Performance ◽  
Teaching Learning ◽  
The Impact ◽  
Experimental Group

Purpose This research applies a quasi-experimental research method to investigate the impact of an innovative resource titled “Accounting Exercise” (teaching intervention using physical movement and lyrics) on learning motivation and performance on a group of students enrolled in a first-year undergraduate accounting course in Japan. Design/methodology/approach Five classes were randomly assigned to either an experimental group (two classes) or a control group (three classes). In the experimental group, 90 students participated in a 15-min “Accounting Exercise” at the commencement of lectures over three consecutive weeks. The remaining 133 students assigned to the control group did not participate in the Accounting Exercise. Findings The findings indicate that the Accounting Exercise provided stimuli in maintaining students’ learning motivation. This finding is important for entry-level students where learning motivation has the potential to influence students’ future decisions on major areas of study and career choices. Originality/value This finding is important for entry-level students where future career options are decided. This effect is also believed to contribute to reducing the declining numbers of students in accounting majors.

Sign in / Sign up

Export Citation Format

Share Document