Preliminary study of Augmented Reality based manufacturing for further integration of Quality Control 4.0 supported by metrology

Augmented Reality (AR) is a key technology enabling Industry 4.0, which enriches human perspectives by overlaying digital information onto the real world. The maturity of AR technology has grown recently. As processes in the automotive and aeronautic sectors require high quality and near-zero error rates to ensure the safety of end-users, AR can be implemented to facilitate workers with immersive interfaces to enhance productivity, accuracy and autonomy in the quality sector. In order to analyse whether there is a real and growing interest in the use of AR as assisting technology for manufacturing sector in general and quality control in particular, two specific research questions are defined. In addition, two well-known research databases (Scopus, Web of Science) are used for the paper selection phase in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology to conduct a preliminary study and evaluate the current development of AR applications in manufacturing sector in order to answer the defined questions. It is found that while the development of AR technology has widely implemented to assign real-time information to several systems and processes in assembly and maintenance sectors, this tendency has only emerged in the quality sector over the last few years. However, AR-based quality control has proved its advantages in improving productivity, accuracy and precision of operators as well as benefits to manufacturing in terms of product and process quality control across different manufacturing phases

Machine tool Verification According to Machine Configuration

AbstractMachine Tool verification is an important issue for metrology. In recent years several efforts has being done in order to increase the methods reliabilities. However, geometrical verification on shop floor and big machines has not being explore as widely, leaving work possibilities open. This article presents a ball bar-based formulae determination method for the 21 MT geometrical errors taking into account the specific machine configuration, as well as its verification and validation

Implementation of the control strategy for a 2D nanopositioning long range stage

A 2D-platform stage able to obtain an effective metrological positioning with nanometer resolution and long working range (50 x 50 mm2) is on development at the University of Zaragoza. The 2D stage has already been designed, manufactured and assembled. The movement of the platform is performed by four custom-made linear motors, and mirror laser interferometers work as positioning sensors in XYRz degrees of freedom. The work here presented focuses on the hardware implementation of the motor control, for one actuator on a 1D linear stage. The developed control strategy acts on three-phase PWM (Pulse-Width Modulation) signals and a feedback is provided by measuring the phase currents. As a preliminary solution, a sensorless algorithm substitutes the positioning sensor before implementing the laser interferometers

Uncertainty budget of a large-range nanopositioning platform based on Monte Carlo simulation

The objective of precision systems design is to obtain machines with very high and totally predictable work-zone accuracies. In already functional systems, where the errors can be measured, this is achieved by error correction and compensation. The aim of this work is to propose an uncertainty budget methodology to obtain the final measuring uncertainty of precise measuring systems, after error compensation. The case study is a nanopositioning platform, referred as NanoPla, with a confocal sensor integrated as measuring instrument. The NanoPla performs precise positioning in a large range of 50 mm × 50 mm, and its target is surface topography characterization, at a submicrometre scale. After performing the uncertainty budget of the NanoPla, Monte Carlo method is used to obtain the final measuring uncertainty along the whole NanoPla working range, considering all the casuistry. By studying the results, the authors are able to propose solutions to minimize the final measuring uncertainty

One-Dimensional Control System for a Linear Motor of a Two-Dimensional Nanopositioning Stage Using Commercial Control Hardware

A two-dimensional (2D) nanopositioning platform stage (NanoPla) is in development at the University of Zaragoza. To provide a long travel range, the actuators of the NanoPla are four Halbach linear motors. These motors present many advantages in precision engineering, and they are custom made for this application. In this work, a one-dimensional (1D) control strategy for positioning a Halbach linear motor has been developed, implemented, and experimentally validated. The chosen control hardware is a commercial Digital Motor Control (DMC) Kit from Texas Instruments that has been designed to control the torque or the rotational speed of rotative motors. Using a commercial control hardware facilitates the applicability of the developed control system. Nevertheless, it constrains the design, which needs to be adapted to the hardware and optimized. Firstly, a dynamic characterization of the linear motor has been performed. By leveraging the dynamic properties of the motor, a sensorless controller is proposed. Then, a closed-loop control strategy is developed. Finally, this control strategy is implemented in the control hardware. It was verified that the control system achieves the working requirements of the NanoPla. It is able to work in a range of 50 mm and perform a minimum incremental motion of 1 mu m

Geometrical characterisation of a 2D laser system and calibration of a cross-grid encoder by means of a self-calibration methodology

This article presents a self-calibration procedure and the experimental results for the geometrical characterisation of a 2D laser system operating along a large working range (50 mm × 50 mm) with submicrometre uncertainty. Its purpose is to correct the geometric errors of the 2D laser system setup generated when positioning the two laser heads and the plane mirrors used as reflectors. The non-calibrated artefact used in this procedure is a commercial grid encoder that is also a measuring instrument. Therefore, the self-calibration procedure also allows the determination of the geometrical errors of the grid encoder, including its squareness error. The precision of the proposed algorithm is tested using virtual data. Actual measurements are subsequently registered, and the algorithm is applied. Once the laser system is characterised, the error of the grid encoder is calculated along the working range, resulting in an expanded submicrometre calibration uncertainty (k = 2) for the X and Y axes. The results of the grid encoder calibration are comparable to the errors provided by the calibration certificate for its main central axes. It is, therefore, possible to confirm the suitability of the self-calibration methodology proposed in this article

Lateral error compensation for stitching-free measurement with focus variation microscopy

This paper proposes a practical methodology to quantify and compensate lateral errors for focus variation microscopy measurements without stitching. The main advantages of this new methodology are its fast and simple implementation using any uncalibrated artefact. The methodology is applied by performing measurements with multiple image fields with and without stitching on an uncalibrated artefact and using the stitched measurements as reference. To quantify the lateral errors, the determination of their geometrical components is carried out through kinematic modelling. With the quantified errors, compensation can be applied for lateral measurements without stitching. Over the entire 200mm lateral range, the lateral errors without stitching and without compensation can reach up to 180 mu m. With the proposed error compensation methodology, the lateral errors have been reduced to around 15 mu m. The proposed methodology can be applied to any Cartesian-based optical measuring instrument

Reference standard for the uncertainty estimation of X–ray Computed Tomography measurements of complex macro-and micro-geometries

Traditionally, measuring both macro and micro geometries with a single device has been challenging in metrology. Coordinate Measuring Machines (CMM) are common devices for the inspection of large features, while optical microscopes can achieve resolutions in the order of micrometers in small areas. X-Ray Computed Tomography (XCT) has become a solution not only to characterize both micro and macro geometries, but also to inspect internal features without destroying the sample. In this field, various reference standards have been developed in order to verify the capabilities of XCT systems, these artefacts include geometrical features or profiles for roughness inspection. This paper shows the design and develompent of a reference standard for XCT test which includes internal and external geometrical features and profiles for macro and micro geometrical inspection. The model is manufactured by additive manufacturing (AM), easing the process of fabrication of the artefact and allowing to test the capabilities of this technology to produce reference standards

Systematic literature review: Integration of additive manufacturing and industry 4.0

The research trend in additive manufacturing (AM) has evolved over the past 30 years, from patents, advances in the design, and layer-by-layer materials, to technologies. However, this evolution is faced with some barriers, such as the implementation of additive manufacturing (AM) in operations, its productivity limitations, and economic and social sustainability. These barriers need to be overcome in order to realize the full potential of AM. The objective of this study is to analyze the bibliometric data on these barriers through a systematic review in two study areas: business model innovation and sustainability in AM from Industry 4.0 perspective. Using the most common keywords in these two study areas, we performed a search on the Web of Science (WoS) and Scopus databases and filtered the results using some inclusion and exclusion criteria. A bibliometric analysis was performed for authorship productivity, journals, the most common keywords, and the identified research clusters in the study areas. For the bibliometric analysis, the BIBEXCEL software was used to extract the relevant information, and Bibliometrix was used to determine the research trend over the past few years. Finally, a literature review was performed to identify future trends in the study areas. The analysis showed evidence of the relationship between the study areas from a bibliometric perspective and areas related to AM as an enabler for Industry 4.0