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

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

Towards Group Decision Support in the Software Maintenance Process

Software maintenance is an element-key of the life cycle of software. However,the techniques of software maintenance do not consider the diversity and the complexity of decisions which do not stop increasing. So, there are at present a few tools, susceptible to insure the relevance and the efficiency of the decision-making in this phase. The work presented in this paper aims to eliminate or at least to reduce the effect to fall in an expensive change by reducing the time to find a compromise on the adequate change. The development of the decision support system for software maintenance is an answer to the problem. The developed tool allows:-to make a fast diagnosis on the software by using the coupling metrics;-to help the decision-makers of the maintenance, according to their preferences often conflicting, to adopt a change among several proposed. To answer this group decision where various points of view are considered, we propose a negotiation protocol. This protocol try to find a compromise that suits best all the decision-makers.

Sistem Status Kelaikudaraan Pesawat Udara Berbasis Website Menggunakan Framework CodeIgniter dan PostgreSQL dengan Metode Prototype

In aircraft operation, maintenance must always be carried out so that the aircraft meets airworthiness standards in order to meet flight safety, in which maintenance is carried out on aircraft components on a regular basis. The problem that exists today is that there is frequent damage to the aircraft without any known cause, even when the aircraft is flown which results in the plane crashing and experiencing severe damage until it can no longer be used. This condition is due to the absence of a system that can monitor the aircraft maintenance process, so that the components of the aircraft used to be flown cannot be known whether it is airworthy or not. The solution to overcome this problem is by building a website-based system. The system was built using the CodeIgniter framework and PostgreSQL as its database. Meanwhile, for system development using the Prototype method. Through this system the aircraft maintenance process can be carried out according to the existing schedule.

Using I2P Encrypted Virtual Tunnels for a Secure and Anonymous Communication in VANets: I2P Vehicular Protocol (IVP)

Providing security and anonymity within VANet requires application of robust and secure models that meet several characteristics of VANet. I2P as a secure protocol designed to anonymize the communication on the internet, can be used as a reference model to develop new mechanisms of security and anonymity in VANet. I2P uses robust mechanisms and strong algorithms to reinforce the security and the anonymity of the communication. However, the difference between internet and VANet in terms of mobility and connectivity of nodes presents a big issue that needs to be treated when using I2P mechanisms in VANet. In the previous work [1], we propose a protocol based on tunnels and encryption algorithms that use digital signatures and authentication mechanisms. Tunnels are created in static scenarios and without maintaining their existence. In this paper, we complete the last version of the proposed protocol (I2P Vehicular Protocol) by integrating a tunnel maintenance algorithm for maintaining the existence of the created tunnels during the communication. This algorithm allows the implementation of the protocol in mobile scenarios of VANet. The effectiveness and security of IVP protocol are proved by analyzing the added part related to the tunnel maintenance process and showing performance results (end-to-end delay, PDR and overhead). Simulation scenarios were executed using NS3 simulator.

Investigation of fault modelling in the identification of bearing wear severity

Recent research into machines involved in the power generation process has demanded deep investigation of model-based techniques for fault diagnosis and identification. The improvement of critical fault characterisation is crucial in the maintenance process effectiveness, hence in time/costs saving, increasing performance and productivity of the whole system. Consequently, this paper deals with a common fault in hydrodynamically lubricated bearings assembled in rotating systems, namely, that of abrasive wear. Research on this topic points to an interesting query about the significance of model detail and complexity and the identification of its characteristic parameters for the important stages of fault diagnosis and fault identification. For this purpose, two models are presented and analysed in their completeness concerning the fault signature by vibration measurements, as well as the identification of fault critical parameters which determine the machine lifetime estimation, maintenance procedures and time costs regarding performance and productivity. From this study, the detailing in fault modelling has a substantial impact on fault parameter identification, even if its improvement is not so expressive in fault diagnosis procedures involving standard signal processing techniques of vibration signatures.

Visualizing Standardized Model-based Design and Inspection Data in Augmented Reality

Augmented reality (AR) has already helped manufacturers realize value across a variety of domains, including assistance in maintenance, process monitoring, and product assembly. However, coordinating traditional engineering data representations into AR systems without loss of context and information remains a challenge. A major barrier is the lack of interoperability between manufacturing-specific data models and AR-capable data representations. In response, we present a pipeline for porting standards-based design and inspection data into an AR scene. As a result, product manufacturing information with three-dimensional (3D) model data and corresponding inspection results are successfully overlaid onto a physical part. We demonstrate our pipeline by interacting with annotated parts while continuously tracking their pose and orientation. We then validate the pipeline by testing against six fully toleranced design models, accompanied by idealized inspection results. Our work (1) pro-vides insight on how to address fundamental issues related to interoperability between domain-specific models and AR systems and (2) establishes an open software pipeline from which others can implement and further develop.

Application of analysis methods and forecasting of time series of indicators of the effectiveness of airworthiness maintaining of civil aircraft

The use of the analysis methodology and forecasting of time series of indicators of the effectiveness of maintaining airworthiness of aircraft of civil aviation made it possible to present the dynamics of indicators as a combination of the regular component, harmonic components with oscillation periods of 12 months and more, and a random component, which represents random processes developing under the influence of groups of factors affecting the airworthiness maintenance process. The results obtained are aimed at improving the safety and effectiveness of aircraft use. Keywords: aircraft, airworthiness, effectiveness of airworthiness maintenance, analysis methodology, forecasting, time series of effectiveness indicators. [email protected]

System of Water Vehicle Power Plant Remote Condition Monitoring

Remote condition monitoring of water vehicles plays an important role in preventing potentially very expensive marine incidents and ensuring maximum efficiency of a ship's operation and reliability with minimum maintenance downtime and repair costs. Concept of the condition-based approach to maintenance is today's best practise, and it is becoming increasingly important to move from planned maintenance to condition-based maintenance, to reduce the increasingly high cost of maintaining a modern fleet. Onboard and remote monitoring is now an essential part of condition-based maintenance process to obtain the good quality data, correct analysis, and effective counteractive actions necessary for such an approach, and article presents the water vehicle power plant monitoring model developed by authors. Considered approach, coupled with preventive maintenance, saves shipowners time and money through early diagnosis of component failure or excess wear. Power plant of water vehicle comprises far more than just an engine with its auxiliary equipment but also other main propulsion blocks – in particular, thrusters. The result was the development of the Water Vehicle Condition Monitoring (WVCM) system, which enables to closely examine water vehicle equipment performance. A WVCM system comprises the following installed onboard: accelerometers, pressure and temperature transmitters, oil, fuel and exhaust monitoring units and a torque measurement system.

Terrain surveillance system with drone and applied machine vision

Road accidents are a major contribution to the Annual death rates all over the world. India, ranks first globally in the number of fatalities from road accidents. According to the Ministry of Roads & Transportation, India saw over 440,000 road accidents in 2019. As a result, over 150,000 lives were lost. Poor road conditions contribute to these directly and indirectly. In India, safety standards and conditions of roads are maintained by local bodies in a given area of jurisdiction. While there have been several attempts at improving the quality of roads, weren’t instrumental in giving proper results [42]. A recent study suggested that Artificial Intelligence (AI) might help achieve the goals. Some of the AI applications have had better results when powered with Computer Vision. While computer vision has been previously used to identify faults in roads, it is not widely implemented or made available for public use. Road inspection still largely remains a time-consuming manual task, hindering the maintenance process in most cities. Moreover, being unaware of unattended faults on roads is often the cause of road accidents, especially in rough weather conditions that make it impossible for drivers to visually gauge any dangers on their route. The proposed model uses a transfer-learning approach; using Mask R-CNN in identifying the defects at an instance level segmentation. As adding this, it requires less labelling and an additional mask helps in blocking out extra noise around the images. This paper trains a Mask R-CNN architecture-based model to identify potholes, discontinuous roads, blind spots, speed bumps, and the type of road--gravel, concrete, asphalt, tar, or mud--with a dataset of images obtained from a drone. The model is further trained to create depth maps and friction estimates of the roads being surveyed. Once trained, the model is tested on a drone-captured live feed of roads in Chennai, India. The results, once sufficiently accurate, will be implemented in a practical application to help users assess road conditions on their path.