Chuan Lv

A modeling approach for maintenance safety evaluation in a virtual maintenance environment

This paper presents a novel virtual maintenance application for maintenance safety evaluation (MSE) to provide recommendations on maintenance safety during the early stages of product design. The proposed methodology detects the potential defects via virtual maintenance technology, and safety evaluation could be carried out in a predictive way intuitively and systemically to decrease the possibility of accidents. After reviewing relevant publications, a MSE model with thorough consideration of the characters in the virtual maintenance environment was addressed. The model consists of evaluation contributors, evaluation criteria, and evaluation methodology. A case study on APU system maintenance was used to illustrate the performance of the evaluation model. The result showed the feasibility of virtual maintenance in improving maintenance safety designs.

Using the swept volume to verify maintenance space in virtual environment

Purpose – Maintainability, as an intrinsic property that shows how well a product can be maintained, should be strictly controlled in the design stage. Maintenance space is an important aspect of maintainability and should be verified in the design stage. Methods to verify maintenance space based on expert knowledge or vision cone have been proposed. However, no proper quantitative solutions have been proposed yet to verify maintenance space in the design stage. This paper aims to provide a new method to evaluate quantitatively the maintenance space in a virtual environment by using the swept volume (SV). Design/methodology/approach – An integrated platform for quantitatively evaluating maintenance space in a virtual environment is designed. Virtual reality technology and digital prototype are used to overcome the shortage of physical prototypes in the design stage. SVs are applied to represent the movement of the hand along the entire maintenance process. Maintenance operations are divided into three bas...

Compensation-based methodology for maintenance time prediction in a virtual environment

Abstract This study presents a novel compensation-based methodology for maintenance time prediction in a virtual environment during the early stage of product design. According to the work procedure in assigning maintenance tasks, a maintenance process simulation is generated on the virtual maintenance platform by following the simulation principle. The basic compensation time or ratio is acquired by analyzing the relationship between practical human motions and corresponding virtual human motions. After that, the compensation principle is confirmed based on the generated simulation principle. Finally, the simulation time and compensation time are approached according to the compensation model to obtain the predicted time. The obtained predicted time of several cases are accurate to a certain extent compared with feedback information.

Human Factors Assessment Based on the Technology of Human Motion Capturing

We aim to combine the technology of capturing human motion and the technology of virtual reality to carry on assessment of human factors. The unique point in this method is that not only the reliable data of the maintenance worker can be gained, but also the quantitative analytic result based on the virtual environment can be obtained. In the paper, human motion capture technology, ergonomics evaluation and the interface technology have been considered comprehensively. overall technical program of human factors evaluation, which is based on human motion capturing technology, have been carried on; the technology, which include the captured data of human motion translating into the virtual environment, building the virtual human model and virtual human simulation, both based on captured data in the working site, are taken as innovations; replicable technology of the captured data in the virtual environment have been broken through. Carrying on the quantitative analysis of worker working postures, fatigue and human force and torque in the maintenance process, which is based on the technology of human factors evaluation by using the captured data in the working site, is researched. We have verified the feasibility of this technology through an example. The method provides a new way and operational technology for human factors assessment in maintenance process of aviation equipment.

Corrective maintenance task ascertain method research based on FMECA

In order to avoid repetitive FMECA (Failure Modes, Effects and Criticality Analysis) in supportability analysis tasks FMECA outcome data from reliability analysis is usually successively utilized tasks. But engineer usually encounter difficulties including that indenture levels definition are difference between reliability and supportability analysis and that FMECA outcomes data may not be directly inputted to MTA (Maintenance Task Analysis) for corrective maintenance task analysis. To solve above difficulties corrective maintenance task ascertainment method was presented according to comparing the difference between FMECA indenture level in reliability and supportability analysis in the precondition of inheriting FMECA outcome data from reliability analysis. Corrective maintenance task ascertainment procedure was constructed prone to operation for engineering. The related analysis worksheets formats were presented. It can be proved that good effects were achieved in terms of the applications in a type of plane development institute. The proposed methodology is demonstrated to make up the gap between FMECA and MTA in supportability analysis. FMECA and supportability analysis data can be seamless integrated.

A mission execution decision making methodology based on mission-health interrelationship analysis

A mission decision making method is presented based on mission-system analysis.The method analyzes the basic interrelationship between mission and modules.The method focuses on the contractive analysis between requirement and capability.This method provides a quantitative suggestion for mission decision making. In this paper, a mission execution decision making methodology is proposed based on the interrelationship between mission requirements and system capability. A mission-system correlation model is established after analyzing mission-function and function-system separately to determine the connections between mission and system. A detailed contrastive analysis between mission requirements and system capability, including transforming intrinsic health into mission health and modules interrelationship analysis, is then conducted for the given mission, which provides quantitative suggestions for objective and timely mission-execution decision making. A case study on a cruise is used to illustrate the performance of the methodology.

Notice of Retraction A maintenance decision-making model based on risk evaluation

Many factors need to be considered for modern weapons and equipment, especially in the operation phase, such as safety, reliability, economy and mission success. Therefore, the paper sets the risk as a comprehensive goal to strike a balance among these various factors. With the weapon characteristics in the operation phase, combining with condition monitoring technology, based on the dynamic risk estimation and evaluation, the paper research a dynamic maintenance decision-making techniques based on risk. According to comparison of the risk level and the acceptable standard, three maintenance decision-making models are established: immediate maintenance, timing on condition maintenance, and rule-based reasoning group maintenance. The entire decision-making process can be divided into three modules: risk estimate, risk evaluation, risk control module.

Research of the military aircraft maintenance support mode based on the prognostics and health management

The paper first introduces the actuality of the maintenance support for domestic military aircrafts. Then, we build the maintenance support system of the military aircraft through the technology of PHM. The system is specified and its impacts on maintenance support under PHM are analyzed, the corresponding maintenance support mode is then researched starting from the four kinds of force of the maintenance support for military aircrafts: institutional maintenance support, contract maintenance support, wartime maintenance support, and information support. Institution maintenance support adopts two-level maintenance system and condition based maintenance; contract maintenance support applies performance based logistics mode; wartime maintenance support seeks for interservice maintenance support and remote support; information support uses two-level information support system and integrative information system. Finally the frame model of the maintenance support mode for military aircrafts is established.

Virtual Maintenance Concepts and Methods

The paper first demonstrates some relevant concepts with virtual maintenance, and further discusses the concepts and connotations of virtual maintenance. As the key techniques, virtual maintenance model and simulation method are studied in the paper. Virtual maintenance model (VMM) is present, and the model is based on Petri Net and can describe the relations of maintenance resources. In addition, virtual maintenance simulation rules are built in the paper. Finally, a case study of the LRU repair of an aircraft is conducted, and the result confirms the validation and feasibility of all the studies, which can become a new technique means for maintainability engineering.

A maintenance time prediction method considering ergonomics through virtual reality simulation

AbstractMaintenance time is a critical quantitative index in maintainability prediction. An efficient maintenance time measurement methodology plays an important role in early stage of the maintainability design. While traditional way to measure the maintenance time ignores the differences between line production and maintenance action. This paper proposes a corrective MOD method considering several important ergonomics factors to predict the maintenance time. With the help of the DELMIA analysis tools, the influence coefficient of several factors are discussed to correct the MOD value and the designers can measure maintenance time by calculating the sum of the corrective MOD time of each maintenance therbligs. Finally a case study is introduced, by maintaining the virtual prototype of APU motor starter in DELMIA, designer obtains the actual maintenance time by the proposed method, and the result verifies the effectiveness and accuracy of the proposed method.