Burr detection and classification using RUSTICO and image processing

.Machined workpieces must satisfy quality standards such as avoid the presence of burrs in edge finishing to reduce production costs and time. In this work we consider three types of burr that are determined by the distribution of the edge shape on a microscopic scale: knife-type (without imperfections), saw-type (presence of small splinters that could be accepted) and burr-breakage (substantial deformation that produces unusable workpieces). The proposed method includes RUSTICO to classify automatically the edge of each piece according to its burr type. Experimental results validate its effectiveness, yielding a 91.2% F1-Score and identifying completely the burr-breakage type.S

A MODEL VISION OF SORTING SYSTEM APPLICATION USING ROBOTIC MANIPULATOR

Image processing in today’s world grabs massive attentions as it leads to possibilities of broaden application in many fields of high technology. The real challenge is how to improve existing sorting system in the Moduler Processing System (MPS) laboratirium which consists of four integrated stations of distribution, testing, processing and handling with a new image processing feature. Existing sorting method uses a set of inductive, capacitive and optical sensors do differentiate object color. This paper presents a mechatronics color sorting system solution with the application of image processing. Supported by OpenCV, image processing procedure senses the circular objects in an image captured in realtime by a webcam and then extracts color and position information out of it. This information is passed as a sequence of sorting commands to the manipulator (Mitsubishi Movemaster RV-M1) that does pick-and-place mechanism. Extensive testing proves that this color based object sorting system works 100% accurate under ideal condition in term of adequate illumination, circular objects’ shape and color. The circular objects tested for sorting are silver, red and black. For non-ideal condition, such as unspecified color the accuracy reduces to 80%.

Experimental investigation on camera calibration for 3D photogrammetric scanning of micro-features for micrometric resolution

[EN] Recently, it has been demonstrated that photogrammetry can be used for the measurement of small objects with micro-features, with good results and lower cost, compared to other established techniques such as interferometry, conoscopic holography, and 3D microscopy. Calibration is a critical step in photogrammetry and the classical pinhole camera model has been tested for magnifications lower than 2×. At higher magnification levels, because of the reduction of the depth of field (DOF), images can lead to calibration data with low reprojection errors. However, this could lead to bad results in the 3D reconstruction. With the aim of verifying the possibility of applying the camera model to magnifications higher than 2×, experiments have been conducted using reflex cameras with 60 mm macro lens, equipped with the combination of three extension tubes, corresponding to 2.06, 2.23, and 2.4 magnification levels, respectively. Experiments consisted of repeating calibration five times for each configuration and testing each calibration model, measuring two artifacts with different geometrical complexity. The calibration results have shown good repeatability of a subset of the internal calibration parameters. Despite the differences in the calibration reprojection error (RE), the quality of the photogrammetric 3D models retrieved was stable and satisfying. The experiment demonstrated the possibilities of the photogrammetric system presented, equipped to very high magnification levels, to retrieve accurate 3D reconstruction of micro-features with uncertainties of few micrometers, comparable with industry s expensive state-of-the-art technologies.Percoco, G.; Guerra, MG.; Sánchez Salmerón, AJ.; Galantucci, LM. (2017). Experimental investigation on camera calibration for 3D photogrammetric scanning of micro-features for micrometric resolution. 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Development of the UMAC-based control system with application to 5-axis ultraprecision micromilling machines

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.Increasing demands from end users in the fields of optics, defence, automotive, medical, aerospace, etc. for high precision 3D miniaturized components and microstructures from a range of materials have driven the development in micro and nano machining and changed the manufacturing realm. Conventional manufacturing processes such as chemical etching and LIGA are found unfavourable or limited due to production time required and have led mechanical micro machining to grow further. Mechanical micro machining is an ideal method to produce high accuracy micro components and micro milling is the most flexible enabling process and is thus able to generate a wider variety of complex micro components and microstructures. Ultraprecision micromilling machine tools are required so as to meet the accuracy, surface finish and geometrical complexity of components and parts. Typical manufacturing requirements are high dimensional accuracy being better than 1 micron, flatness and roundness better than 50 nm and surface finish ranging between 10 and 50 nm. Manufacture of high precision components and parts require very intricate material removal procedure. There are five key components that include machine tools, cutting tools, material properties, operation variables and environmental conditions, which constitute in manufacturing high quality components and parts. End users assess the performance of a machine tool based on the dimensional accuracy and surface quality of machined parts including the machining time. In this thesis, the emphasis is on the design and development of a control system for a 5-axis bench-type ultraprecision micromilling machine- Ultra-Mill. On the one hand, the developed control system is able to offer high motion and positioning accuracy, dynamic stiffness and thermal stability for motion control, which are essential for achieving the machining accuracy and surface finish desired. On the other hand, the control system is able to undertake in-process inspection and condition monitoring of the machine tool and process. The control of multi-axis precision machines with high-speed and high-accuracy motions and positioning are desirable to manufacture components with high accuracy and complex features to increase productivity and maintain machine stability, etc. The development of the control system has focused on fast, accurate and robust positioning requirements at the machine system design stage. Apart from the mechanical design, the performance of the entire precision systems is greatly dependent on diverse electrical and electronics subsystems, controllers, drive instruments, feedback devices, inspection and monitoring system and software. There are some variables that dynamically alter the system behaviour and sensitivity to disturbance that are not ignorable in the micro and nano machining realm. In this research, a structured framework has been developed and integrated to aid the design and development of the control system. The framework includes critically reviewing the state of the art of ultraprecision machining tools, understanding the control system technologies involved, highlighting the advantages and disadvantages of various control system methods for ultraprecision machines, understanding what is required by end-users and formulating what actually makes a machine tool be an ultraprecision machine particularly from the control system perspective. In the design and development stage, the possession of mechatronic know-how is essential as the design and development of the Ultra-Mill is a multidisciplinary field. Simulation and modelling tool such as Matlab/Simulink is used to model the most suitable control system design. The developed control system was validated through machining trials to observe the achievable accuracy, experiments and testing of subsystems individually (slide system, tooling system, monitoring system, etc.). This thesis has successfully demonstrated the design and development of the control system for a 5-axis ultraprecision machine tool- Ultra-Mill, with high performance characteristics, fast, accurate, precise, etc. for motion and positioning, high dynamic stiffness, robustness and thermal stability, whereby was provided and maintained by the control system

Recent research on flexible fixtures for manufacturing processes

Fixtures, are used to fixate, position and support workpieces, and form a crucial tool in manufacturing. Their performance influences the manufacturing (and assembly) process of a product. Furthermore, fixturing can form a significant portion of the needed investment and total process planning time for the manufacturing system. Many fixturing concepts, as contribution to increase the flexibility of the manufacturing system, are reported in the literature. The flexible fixturing designs can be classified into the following seven categories: modular fixtures, flexible pallet systems, sensor-based fixture design, phase-change based concepts, chuck-based concepts, pin-type array fixtures and automatically reconfigurable fixtures. It is observed that the more intelligent and automated fixturing systems are designed with the demands for automation in certain industries in mind. Furthermore, different fixturing solutions suit the engineering demands for different manufacturing areas, this means that for the foreseeable future all technologies will remain current. From the self-reconfigurable fixturing techniques a new fixturing capability is emerging: in process reconfigurability for the optimal placement of clamps and supports during the whole process time. These several concepts together with some recent patents are studied here. The paper concludes with some prospective research directions in the field of flexible fixturing

A New Measurement Method of Relative Volume Wear Ratio Based on Discharge Debris Composition Analysis in Micro-EDM

In microelectrical discharge machining (micro-EDM) milling process, due to the unavoidability of electrode wear, selection of electrode with high electrical erosion resistance and accurate electrode compensation is entitled to be conducted to ensure high precision and high quality. The RVWR is used as criterion for electrode wear characteristics and is fundamental to achieve accurate electrode compensation; however, it is hardly measured accurately with conventional methods. In this paper, firstly, the error of RVWR measured by conventional measurement method is analyzed. Thereafter, for accurately measuring RVWR, a new measurement method is proposed based on electrical debris composition analysis. The RVWR of widely used tungsten, molybdenum, and copper electrode in machining different materials is measured, respectively, and the optimum electrode is selected based on the measuring results. Finally, microgrooves on different materials are machined with tungsten electrode, and the experiment results show that the microstructures have good bottom surface profiles, which indicates that the proposed method is effective to precisely measure the RVWR and guarantee accurate electrode compensation in micro-EDM process

Study On The Effect Of Tool Nose Wear On Surface Roughness And Dimensional Deviation Of Workpiece In Finish Turning Using Machine Vision.

Operasi pemesinan merupakan suatu kaedah umum bagi menghasilkan komponen-komponen mekanikal yang dikeluarkan di segenap pelusuk dunia. Permintaan terhadap perkakas mesin dalam setahun dilaporkan mencecah lebih daripada £10 bilion. The aim of this research is to study the direct effect of tool nose wear which is in contact to the surface profile of workpiece directly, on the surface roughness and dimensional deviation of workpiece using a developed machine vision in finish turning operation

Collision avoidance and adaptive path planning in machine tools by matching live image data with a geometric simulation

A major cause for unplanned downtime in small-series machining are collisions. While there are solutions to avoid collisions using geometric simulations, these do not cover collisions caused by setup errors. To address this problem from batch size one, a system has been developed which matches a geometric simulation with image data to detect deviations, modify the simulation and recalculate NC-Code to fit reality. Building on previous work regarding image-preprocessing, an iterative matching algorithm is developed, as well as a microservice based system-architecture which allows the integration of matching, adaptive path planning and collision avoidance simulation. The system is validated on a machining center

Micromechanics as a testbed for artificial intelligence methods evaluation

Some of the artificial intelligence (AI) methods could be used to improve the performance of automation systems in manufacturing processes. However, the application of these methods in the industry is not widespread because of the high cost of the experiments with the AI systems applied to the conventional manufacturing systems. To reduce the cost of such experiments, we have developed a special micromechanical equipment, similar to conventional mechanical equipment, but of a lot smaller overall sizes and therefore of lower cost. This equipment can be used for evaluation of different AI methods in an easy and inexpensive way. The methods that show good results can be transferred to the industry through appropriate scaling. This paper contains brief description of low cost microequipment prototypes and some AI methods that can be evaluated with mentioned prototypes.Applications in Artificial Intelligence - ApplicationsRed de Universidades con Carreras en Informática (RedUNCI

Aspects of automation in the shoe industry

The shoe manufacturing industry has undergone a revolution during the last 50 years, due to the introduction of task specific machinery. Great technological strides have been made in the areas of shoe manufacture prior to actual component assembly. Computer systems are now becoming the norm for the design of shoes for today's market place. Technological innovations have also started to be applied in the assembly and construction processes of modern shoes. Computer controlled cutting machines calculate the optimum usage of leather from any given hide, new machines allow decorative stitch patterns to be associated with a given shape and size of component and automatically stitched on to the presented workpiece. However the majority of assembly operations have remained predominantly manual with technology playing a secondary role to the human operator due to complexities either in manipulation, control or sensing. In these machines electronic and mechanical innovations have been used to add new features to often simple machines and in some cases to simplify some of the more complex operations, thus increasing productivity but reducing the required dexterity and knowledge of an operator. Modern preferences in industry are to utilise fully automated machines, that are as operator independent as possible, thus improving quality, consistency and production speed whilst at the same time reducing production costs.Due to the nature of the shoe manufacturing industry and the complex operations that have to be performed in order to construct a shoe, machinery manufacturers who have ventured into this field of automation have generally struggled to gain acceptance from the shoe makers as the machinery is generally complex and slow in operation. This together with the fact that a large proportion of the world's main footwear production is centred in the far east, with their correspondingly low labour costs, has held back the automation of the shoe  manufacturing industry.This thesis examines a selection of operations encountered in the construction of a typical shoe. These include operations for processing single flat component parts as well as more complex three-dimensional operations encountered when lasting and soling a shoe. The aim of the research was to develop an understanding of processes encountered in specific areas within the shoe manufacturing industry in order to identify areas where further advances in automation could be achieved. This understanding has been applied to produce proposals and in some cases hardware, to allow for the development of working systems