6,049 research outputs found

    NASA space station automation: AI-based technology review

    Get PDF
    Research and Development projects in automation for the Space Station are discussed. Artificial Intelligence (AI) based automation technologies are planned to enhance crew safety through reduced need for EVA, increase crew productivity through the reduction of routine operations, increase space station autonomy, and augment space station capability through the use of teleoperation and robotics. AI technology will also be developed for the servicing of satellites at the Space Station, system monitoring and diagnosis, space manufacturing, and the assembly of large space structures

    Estimating the Lead Time Distribution of Priority Lots in a Semiconductor Factory

    Get PDF
    We consider the lead time of priority lots in a semiconductor factory. The main cause of delays is waiting for repairs of failed machines, and the failures are mainly caused by power disturbances. This can be modeled as an exogenous time-dependent failure process, and we develop a probabilistic model of the system based on this. Using this model, a convolution algorithm for finding the lead time distribution is described. We describe a method of creating synthetic samples of the lead time from historical failure and repair data collected in the factory. Based on such a sample from the MIT Integrated Circuits Laboratory, we approximate the distribution of lead times by a gamma probability density function shifted by the smallest possible lead time for the product type. The parameters of the gamma distribution are found by using a maximum likelihood estimator. The resulting distribution gives good agreement with the synthetic data for values less than two standard deviations above the mean lead time. Since our procedure only depends on a description of the process and the failure and repair history of the factory, it can also be used to obtain lower bounds on the lead time for new product types

    An agile and adaptive holonic architecture for manufacturing control

    Get PDF
    Tese de doutoramento. Engenharia Electrotécnica e de Computadores. 2004. Faculdade de Engenharia. Universidade do Port

    NASA space station automation: AI-based technology review. Executive summary

    Get PDF
    Research and Development projects in automation technology for the Space Station are described. Artificial Intelligence (AI) based technologies are planned to enhance crew safety through reduced need for EVA, increase crew productivity through the reduction of routine operations, increase space station autonomy, and augment space station capability through the use of teleoperation and robotics

    Constraint-based Scheduling for Closed-loop Production Control in RMSs

    Get PDF
    Reconfigurable manufacturing systems (RMS) are conceived to operate in dynamic production contexts often characterized by fluctuations in demand, discovery or invention of new technologies, changes in part geometry, variances in raw material requirements. With specific focus on the RMS production aspects, the scheduling problem implies the capability of developing plans that can be easily and efficiently adjusted and regenerated once a production or system change occurs. The authors present a constraint-based online scheduling controller for RMS whose main advantage is its capability of dynamically interpreting and adapting to production anomalies or system misbehavior by regenerating on-line a new schedule. The performance of the controller has been tested by running a set of closed-loop experiments based on a real-world industrial case study. Results demonstrate that automatically synthesizing plans and recovery actions positively contribute to ensure a higher production rate

    Advancing automation and robotics technology for the Space Station and for the US economy, volume 2

    Get PDF
    In response to Public Law 98-371, dated July 18, 1984, the NASA Advanced Technology Advisory Committee has studied automation and robotics for use in the Space Station. The Technical Report, Volume 2, provides background information on automation and robotics technologies and their potential and documents: the relevant aspects of Space Station design; representative examples of automation and robotics; applications; the state of the technology and advances needed; and considerations for technology transfer to U.S. industry and for space commercialization

    An improvement of a cellular manufacturing system design using simulation analysis

    Get PDF
    Cell Formation (CF) problem involves grouping the parts into part families and machines into manufacturing cells, so that parts with similar processing requirements are manufactured within the same cell. Many researches have suggested methods for CF. Few of these methods; have addressed the possible existence of exceptional elements (EE) in the solution and the effect of correspondent intercellular movement, which cause lack of segregation among the cells. This paper presents a simulation-based methodology, which takes into consideration the stochastic aspect in the cellular manufacturing (CM) system, to create better cell configurations. An initial solution is developed using any of the numerous CF procedures. The objective of the proposed method which provides performances ratings and cost-effective consist in determine how best to deal with the remaining EE. It considers and compares two strategies (1) permitting intercellular transfer and (2) exceptional machine duplication. The process is demonstrated with a numerical exampleCell Formation; Exceptional Elements; Simulation; Alternative costs; Improvement

    Smart manufacturing scheduling: A literature review

    Full text link
    [EN] Within the scheduling framework, the potential of digital twin (DT) technology, based on virtualisation and intelligent algorithms to simulate and optimise manufacturing, enables an interaction with processes and modifies their course of action in time synchrony in the event of disruptive events. This is a valuable capability for automating scheduling and confers it autonomy. Automatic and autonomous scheduling management can be encouraged by promoting the elimination of disruptions due to the appearance of defects, regardless of their origin. Hence the zero-defect manufacturing (ZDM) management model oriented towards zero-disturbance and zero-disruption objectives has barely been studied. Both strategies combine the optimisation of production processes by implementing DTs and promoting ZDM objectives to facilitate the modelling of automatic and autonomous scheduling systems. In this context, this particular vision of the scheduling process is called smart manufacturing scheduling (SMS). The aim of this paper is to review the existing scientific literature on the scheduling problem that considers the DT technology approach and the ZDM model to achieve self-management and reduce or eliminate the need for human intervention. Specifically, 68 research articles were identified and analysed. The main results of this paper are to: (i) find methodological trends to approach SMS models, where three trends were identified; i.e. using DT technology and the ZDM model, utilising other enabling digital technologies and incorporating inherent SMS capabilities into scheduling; (ii) present the main SMS alignment axes of each methodological trend; (iii) provide a map to classify the literature that comes the closest to the SMS concept; (iv) discuss the main findings and research gaps identified by this study. Finally, managerial implications and opportunities for further research are identified.This work was supported by the Spanish Ministry of Science, Innovation and Universities project entitled 'Optimisation of zero-defects production technologies enabling supply chains 4.0 (CADS4.0) ' (RTI2018-101344-B-I00) , the European Union H2020 research and innovation programme with grant agreement No. 825631 "Zero Defect Manufacturing Platform (ZDMP) " and the European Union H2020 research and innovation programme with agreement No. 958205 "In-dustrial Data Services for Quality Control in Smart Manufacturing (i4Q) ".Serrano-Ruiz, JC.; Mula, J.; Poler, R. (2021). Smart manufacturing scheduling: A literature review. Journal of Manufacturing Systems. 61:265-287. https://doi.org/10.1016/j.jmsy.2021.09.0112652876
    • …
    corecore