Browse Topic: Nonconventional machining processes

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Smart Manufacturing ControlTBMG-359972/1/2020
The manufacturing process of today involves many challenges, from mass production down to a lot size of one. The CNC controls in factories have to master this market trend without an adequate amount of skilled labor in the US manufacturing world. In essence, manufacturing is facing a renaissance in the CNC control technology shift.
Collaborative Automation: It's More Than Just the CobotTBMG-3560812/1/2019
Collaborative robots, often called “cobots,” offer opportunities for companies of almost any size to cost-effectively automate processes that were previously out of reach. Cobots are available in a wide range of sizes, payloads, and capabilities but they all share attributes that define the term “collaborative.” The aspect that most people think of first is safety — the ability for cobots to work alongside human workers without bulky, expensive guarding. Cobots include a number of built-in safety mechanisms including rounded edges and softer materials as well as power-and force-limiting technologies that avoid injury and minimize discomfort in case of contact, and sensors that automatically slow or stop the robot arm if a human enters its workspace.
Fault Detection in Single Stage Helical Planetary Gearbox Using Artificial Neural Networks (ANN) and Decision Tree with Histogram Features2019-28-015110/11/2019
Drive train failures are most common in wind turbines. Lots of effort has been made to improve the reliability of the gearbox but the truth is that these efforts do not provide a lifetime solution. Majority of failures are caused by bearing and gearbox. It also states that wind turbine gearbox failure causes the highest downtime as the repair has to be done at Original Equipment Manufacturer [OEM]. This work aims to predict the failures in planetary gearbox using fault diagnosis technique and machine learning algorithms. In the proposed method the failing parts of the planetary gearbox are monitored with the help of accelerometer sensor mounted on the planetary gearbox casing which will record the vibrations. A prototype has been fabricated as a miniature of single stage planetary gearbox. The vibrations of the healthy gearbox, sun defect, planet defect and ring defect under loaded conditions are obtained. The signals show the performance characteristics of the gearbox condition. These characteristics and their number of occurrences were plotted in a histogram graph. Predominant statistical features which represent the fault condition were selected using decision tree algorithm. Using these features the Artificial Neural Network (ANN) and J48 algorithms were trained and tested to classify the faults. The accuracy of the machine learning algorithm greatly helps in deciding the optimum time to carry out the required maintenance operation.
Shaul Hameed, Syed, Vaithiyanathan, Muralidharan, Kesavan, Mahendran
Optimization of Machining Process Parameters for Minimizing the Waste Stream Response through Multi-Objective Optimization2019-28-006210/11/2019
During the delivering of an item, any material created moreover to a definitive item will be named as waste. The waste produced in light of machining could be a notable conservation worry for creators. The shape and condition of waste streams created, and their transportation components divergence with the strategy utilized and also shift among the technique. The effect in view of each waste stream differs as well. This examination reports a machining strategy includes the procedure of material to give a completed or a semi-completed item. This is frequently done by misapplication tools, totaling, machines and distinctive data sources that are appropriate to the strategy. The procedures thought of for the point of this work includes machining of material manipulation devices to give parts and items. The yield of the technique incorporates the item and increase the waste streams. The waste streams will be in the form of Chips, Energy usage, and Worn cutting tools and Operating time. TOPSIS and ANOVA was acclimated gauge the chief essential Cutting speed, Feed rate, Depth of Cut and Tool Nose Radius conditions that influencing the Minimum Response. The most support effect of the info factors on the normal reactions is researched. The normal esteems and estimated esteems are genuinely close. The given model may be acclimated pick the measure of machining process parameters.
Sivam Sundarlingam Paramasivam, Sundar Singh, Loganathan, Ganesh Babu, Saravanan, Krishnaswamy, Kumaran, Durai, Rajendran, Raj, Sriram, Harish
Multi Response Optimization on Machining Titanium Alloy Using Taguchi-DEAR Analysis in Abrasive Water Jet Cutting2019-28-007010/11/2019
Abrasive water jet cutting has been proven to be an effective technology for processing various engineering materials. This paper investigated the effects of process parameters on depth of cut in abrasive water jet cutting of titanium alloy. Four different process parameters were undertaken for this study; water pressure, nozzle traverse speed, abrasive mass flow rate and standoff distance. The influence of these process parameters on depth of cut, surface roughness and MRR has been investigated and analyzed. An empirical model for the prediction of depth of cut in abrasive water jet cutting of cast iron has been developed using regression analysis. The approach is based on Taguchi-DEAR method to optimize the AWJM process parameter for effective machining. It has been found that the stand-off-distance has highest impact on performance measures among all process parameters.
Thangaraj, Muthuramalingam, Loganathan, Ganesh Babu, Atif, Akhtar, Palanisamy, Srinivasan
Application of Response Surface Method to Optimize Waterjet Cutting Process Parameter of Glass Fiber Reinforced Polymer Matrix Laminates2019-28-015310/11/2019
Waterjet machining is a widely used advanced machining technique because of its versatility in removal of material for a wider range of materials. Waterjet machining is particularly advantageous in the precise cutting of advanced materials like Fiber Reinforced Polymers (FRPs) comparative to conventional machining methods. The conventional machining methods result in the release of high amount of glass fiber dust which leaves the work environment unsafe for the workers. The material dust if inhaled can lead to acute respiratory diseases. In this work an analysis was done on the cutting performance of Waterjet machining and is presented based on an experimental investigation on fabricated fiberglass reinforced laminates. It is shown that with a good combination of cutting parameters such as nozzle traverse speed, waterjet pressure, and Stand-off distance a cutting performance can be achieved. Plausible trends of kerf quality and machining time with respect to the waterjet pressure, nozzle traverse speed and nozzle stand-off distance are analysed. The surface roughness and machining time has been optimized using DOE techniques for achieving proper machining characteristics and faster completion of the work. An experimental study of WJM of Glass epoxy composite to improve kerf properties is presented. The RSM a well-renowned technique is used to optimize the process parameters.
Aulakh, Savitoj Singh, Patil, Dhanush, Elsen, Renold, Aggarwal, Sangeet
Vision Based Surface Roughness Characterization of Flat Surfaces Machined with EDM2019-28-014810/11/2019
Surface roughness measurement is an important one in any manufacturing next to dimensions. In this investigation, a vision system and image processing tools were used to develop reliable surface roughness characterization technique for Electrical Discharge Machined surfaces. A CMOS camera with red LED light source were used for capturing images of EDMed surfaces. A separate signal vector generated for all the images from its image pixel intensity matrices. The mean, skewness and kurtosis were obtained from the signal vector. The mean, skewness and kurtosis of the images signal vector correlates very well with the stylus measured hybrid roughness parameters Rda and Rdq. Hence the technique may be preferred for online surface roughness characterization of Electrical Discharge Machined (EDMed) surfaces.
Ali, Mahashar, Jailani, Siddhi, Mariappan, Murugan, Anandan, Mangalnath, Pavithran, Vignesh
Assessing Viscosity in Hydro-Erosive Grinding Process via Refractometry04-12-03-00128/22/2019
The manufacturing of diesel injector nozzles requires precision processing to produce multiple micro-holes. An abrasive fluid containing a mixture of mineral oil and hard particles is used for rounding them, ensuring the hydrodynamics of the injection. As verified in a previous investigation, the viscosity of the fluid undergoes uncontrolled changes during hydro-erosive (HE) grinding. Such undesired viscosity changes are detrimental to the process and difficult to assess. The current investigation aims to study the possibility of using the refractive index of the oils used in the HE grinding for assessing their viscosities. A calibration curve correlating the refractive index and viscosity was obtained from the analysis of samples produced by mixing two distinct mineral oils in different proportions. The determined calibration curve was tested with 45 samples of filtered oil, collected directly from the tanks during the HE grinding. The results showed that refractometry is a potential technique for online control of grinding efficiency.
Heidemann, Bárbara R., Scherpinski, Gustavo, Fabris, Luís, Muller, Marcia, Fabris, José L., Pintaude, Giuseppe
Cross-Training Made Possible by Common Control PlatformTBMG-345796/1/2019
EMAG L.L.C. is the U.S. subsidiary of a major German machine tool builder that specializes in machine tools for the production of automotive, off-highway, agricultural, and oil field components. The company’s equipment ranges from basic round part turning centers to large-workpiece, five-axis machining centers; gear hobbing machines; and alternative equipment such as laser welding and electrochemical machining centers. This wide variety of machine tools requires an assortment of control technologies to power and manage the motion. For one customer requirement where a major agricultural equipment builder needed grinding, turning, and turn-grind machines, EMAG looked to Siemens for a standardized CNC solution.
A New Method for Multi-objective Optimal Design of Milling Parameters by Considering Chatter Vibrations2019-01-50435/13/2019
The desired milling process with high material removal rate (MRR) and low surface roughness of the product can be achieved only if machining chatter is absent. Incorporating chatter into the optimal selection of the machining parameters leads to a complex problem. Therefore, the approach of selecting conservative intervals for the machining parameters is usually employed instead. In this paper, a practical approach is proposed to specify the optimal machining parameters (depth of cut and spindle speed) in order to maximize MRR and minimize forced vibrations by considering machining chatter. Firstly, the worst-case scenario-based optimization problem in terms of the surface quality is solved to find the critical time at which maximal amplitude vibrations occur. Then, the time dependency of the problem is eliminated. Secondly, the multi-objective optimization is conducted to achieve the Pareto Optimal Front (POF). The Stability Lobe Diagram (SLD) is obtained independently through well-established analytical methods. Optimal machining parameters on the obtained POF are mapped into the SLD to represent optimal results for the cases at which machining chatter is absent. Finally, these optimal results are sorted by the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) decision-making method and displayed on the combined POF-SLD diagram which can be used by the machining operator for determination of the process parameters. A case study is considered, illustrating the efficiency of the proposed method.
Jafarzadeh, E., Khodaygan, S., Sohani, A.
Dynamic Modeling of CNC Drive Systems: Comparison of Two Models2019-01-08034/2/2019
Accurate positioning and precision of CNC machines are directly affected by performance of their mechanical drive system and control unit (CNC feeddrive system). This is more important in contouring operations where axes motion is synchronized by interpolators and errors are accumulative. This research work is focused on study of dynamics of the feeddrive unit. In this regard, a detailed dynamic model is developed in state-space format that is used to study its response properties. A parametric study of the system is carried out by studying shifts in eigenvalue loci when a parameter is changed. The results are used in further simplifying this model to a reduced order system which is simpler in structure and more appropriate for control applications. A comparison is made between these models and the merits of each individual model are presented.
Mehrabi, Mostafa
Digital Manufacturing Helps Medtech Firm's Goal to Improve Patient OutcomesTBMG-342614/1/2019
As often happens in the medical industry, innovative ideas hatched in university research settings spawn innovative companies, which create innovative products. A case in point: HemoSonics. The Charlottesville, VA-based medical device company was started in 2005 by two professors and a post-doctoral research student at the University of Virginia School of Medicine's Bio-Medical Engineering program — Bill Walker, Mike Lawrence, and Francesco Viola, respectively. The trio identified a method for measuring the stiffness of blood clots by using ultrasound imaging technology and created a system built around that technology aimed to improve patient outcomes and reduce costs.
Metal Additive ManufacturingTBMG-3336012/1/2018
Additive manufacturing (AM) – the process of building up solid layers of material to form a finished solid part — is an emerging and exciting technical discipline. Also referred to as “3D printing,” many misconceptions exist about the capabilities and promises of the technology.
ABNT 4140 steel mechanical properties after nitriding by EDM process2018-36-03259/3/2018
Electrical Discharge Machining process (EDM) is a non-conventional cutting method applicable for the machining of electrically conductible or semi-conductible, with no contact between the tool and the work piece which consists in an electrode and a work piece both submerged in a dielectric fluid and connected into a direct current source. Initially, the fluid behaves in an insulating way so that there is no electric current until a minimum gap between the electrode and the work piece is reached. Once this gap is reached, the dielectric fluid starts behaving in a conductive way creating a plasma channel due to the electric arc generated. Ion are emitted between the anode and the cathode thus colliding with the dielectric fluid molecules obtaining enough energy to fuse/vaporize and consequently removing material from the work piece/electrode. The main objective of this study was to adapt the conventional EDM machine, so that it could allow performing the NDE (Nitriding by Electrical Discharge) while the test sample rotates. Therefore, it became possible to evaluate the results of the NDE process on test samples submitted on the traction resistance test. In order to evaluate the gain in surface hardness and the substract hardness after NDE, it was necessary to elaborate a triparted proof body, allowing the removal of proof body central part for a subsequent microhardness evaluation. In this way, it became possible to preserve the machined surface and consequently better results during the microhardness evaluation. As a dielectric fluid utilized on the test was a deionized water with urea concentration varying among 0g/l, 20g/l, 40g/l, 60g/l and 80g/l, the purpose of the urea variation was evaluate the influence of urea concentration on the surface hardness and nitrided layer depth.
Quirino, Cid Clay, Neumann, Lucas
Diamond Pellet Grinding ToolTBMG-325108/1/2018
NASA Marshall Space Flight Center has developed a numerically controlled grinding tool that eliminates undesirable periodic variations in surface contours in optical and other surfaces — such as mid-spatial frequency errors — that result from polishing. It can also be used to eliminate any undesirable irregularities in optical surfaces — either flat, curved, or aspheric — as well as other precision surfaces such as orthopedic joint replacements.
Application of TOPSIS with Taguchi Method for Multi-Attribute Optimization of Machining Parameters in EDM2018-28-00337/9/2018
The present work focused on application of TOPSIS along with Taguchi method to optimize machining parameters in Electrical Discharge Machining (EDM) of Titanium alloy (Ti-6Al-4 V) considering it as multi-attribute problem. The L9 orthogonal array of Taguchi method is used to conduct experiments. During experimentation Titanium alloy (Ti-6Al-4 V) is chosen as a work material and electrolyte copper is selected as a tool electrode. Whereas peak current, pulse on time and pulse off time are chosen as machining parameters. TOPSIS method is applied to determine the optimal combination of machining parameters to yield maximum material removal rate MRR), minimum tool wear rate (TWR) and surface roughness (SR) simultaneously. Confirmation experiments have been done at optimal parametric setting, then results are compared with predicted values and it was found that percentage error is less than 5.
Vaddi, Vikram Reddy, Ch, Sridhar Reddy, Bushaboina, Shiva Kumar, Banka, Hemasunder
Optimization of Electrical Discharge Machining of Titanium Alloy (Ti-6Al-4 V) Using Taguchi-DEAR Method2018-28-00327/9/2018
Electrical discharge machining (EDM) process is widely used unconventional machining process in manufacturing industry for machining high hardness materials and to make dies of complex cavities. In this work experiments are carried out during electric discharge machining of Titanium alloy (Ti-6Al-4 V). Taguchi L9 orthogonal array is used to conduct experiments. Process parameters, such as, peak current, pulse on time and pulse off time are chosen for this study. Whereas performance characteristics namely material removal rate (MRR), tool wear rate (TWR) and surface roughness (SR) are selected for this study. The significance of process parameters on performance characteristics is analyzed. The objective of present work is to find optimal combination of parameters that gives maximum MRR and minimum TWR and SR simultaneously. Taguchi-data envelopment analysis-based ranking method is used for above multi-response optimization.
Vaddi, Vikram Reddy, Ch, Sridhar Reddy, Pogaku, Vamshi Krishna, Bushaboina, Shiva Kumar
Optimization of Process Parameters for Electro Discharge Machining of Al 7075-Al 2 O 3 Nano Composite Using Different Electrode Materials2018-28-00937/9/2018
In the present study, an aluminium based nanocomposite, reinforced with 2 wt. % aluminium oxide (Al2O3) is developed through stir casting method. These hard ceramic particles also influence the material removal rate (MRR), electrode wear rate (EWR) and surface finish (Ra) in an electro-discharge machining (EDM) process. In this work, EDM of Al 7075/2 wt. % Al2O3 nanocomposite is carried out using copper and brass electrodes using Taguchi L18 array. The percentage contribution of each process parameter on the response variables was determined using analysis of variance (ANOVA). Multi-response signal to noise ratio (MRSN) and the optimum combination levels for the input parameters was obtained using Taguchi’s parametric design. MRR and surface roughness are substantially improved when machining is performed at optimized conditions.
C, Kannan, Ramanujam PhD, R, Balan PhD, A S S, Vijayakumar, T, Karunakaran, C
Digital Manufacturing Helps Revolutionize Surgical StaplerTBMG-297487/1/2018
Modern science has allowed surgeons to fix the human body amazingly fast yet leave behind only small traces where repairs were performed. One of the more commonly used methods to achieve this is by a minimally invasive technique called laparoscopic surgery, where small incisions are made into a patient's skin, a laparoscope is inserted to provide a magnified view of the patient's organs, the procedure is performed, and the incision is closed by stitching or surgical staples. You can have your gallbladder removed before breakfast and be binge-watching Netflix from the comfort of your couch by dinner.
Advanced Techniques For The Fabrication Of Airframe Structures Using Innovative Friction Stir Welding (FSW) TechnologyF-0074-2018-128045/14/2018
ABSTRACT One of the alternative method for welding method is a friction stir welding (FSW), which was developed in 1991 at TWI (The Welding Institute) in the United Kingdom, initially especially for joining aluminum and its alloys [1]. This process consists in joining of materials in solid state, which eliminates the problems resulting from melting the material and its re-solidifying, such as, hot cracking, residual stresses and distortion created during conventional welding. In this process, the heat which plasticized the material is provided by rotating tool consisting of shoulder and pin. This tool penetrates into the base material and then moves along the welding line. As a result of the friction between tool and joining materials is generated a sufficient amount of heat allowing on mixed the base material and create FSW joint. Among the most important advantages of using the FSW method should be listed: relatively easy automatization (it is often possible to use conventional CNC machine), lower residual stresses in the welded joints and their very good mechanical properties (often exceed the mechanical properties of welded or riveted joints). Project FAST_FSW (Advanced techniques for the Fabrication of Airframe STructures using innovative friction stir welding (FSW) technology) is realized within consortium between PZL Mielec and research partner Czestochowa University of Technology. The main objective of the FAST_FSW Project is to develop friction stir welding technology to aircraft design and manufacturing for introduce fasteners free, lighter weight and lower cost aerostructures.
Luty, Grzegorz, Wronska, Agata, Andres, Jacek, Galaczynski, Tomasz
Multi-Axis Voxel-Based CNC Machining of Centrifugal Compressor AssembliesF-0074-2018-127985/14/2018
ABSTRACT The use of computer-aided manufacturing (CAM) software is essential in the rapid production of high-quality computer numerical control (CNC) machining toolpaths for complex parts. Typical CAM software relies on analytical representations of part geometry, where curves and surfaces are described by parametric functions. This paper proposes the use of a novel way to represent part geometry known as a voxel model. A voxel model uses a three-dimensional array of small cubes to represent a part volume; these cubes, or voxels, are the three-dimensional analog of two-dimensional pixels in an image. The use of voxels for a CAM application enables higher surface complexity, simplified collision checking, and more robust analysis of material removal than would be possible with typical parametric CAM. The unique capabilities of the voxel-based CAM approach described in this paper enable rapid production of high-quality 5-axis toolpaths for machining complex parts, such as the centrifugal compressor assembly that is presented in this work.
Kurfess, Thomas, Tucker, Tommy, Silberglied, Chelsea, Lynn, Roby, Saleeby, Kyle, Saldana, Christopher
Advanced Machining and Automation Reduce Medical Device Tubing CostsTBMG-2785411/1/2017
In order to stay competitive in today’s medical device marketplace, it is imperative that companies continually invest in the latest technologies to ensure that they produce the highest quality metal tubing products, while also reducing costs. To meet these demands, full-service contract manufacturing operations must also be vertically integrated to handle complex medical device tubing projects.
True Mobile/Portable Drilling and Machining, a Paradigm Shift in Manufacturing2017-01-20849/19/2017
The evolving Aerospace manufacturing environment has created challenges that until now are not achievable with standard machine tools, large monumental gantry style machines and robots, or even manually operations. The solution is a lightweight, mobile/portable, and modular PKM (Parallel Kinematics Machine) solution, capable of machining to high tolerances, with minimal time and effort to relocate to a different area, at an affordable price With the carbon fiber PKM module mounted on a mobile platform, the module can simply be relocated using a standard pallet mover or forklift, to all areas in a factory. The module can also be removed from the mobile platform by two people, and mounted in a desired location and in any orientation “in hours”. The modularity of the PKM does not only make it possible to move it around in different production areas, but also makes it possible to reconstruct in an area that is not typically accessible by machines or robots. Acting as a mobile machine tool the PKM also eliminates special foundations, leveling of the machine prior to use, high accuracy fixtures, constant recalibration necessary for accurate robotic applications, laborious jig set up for manual operations and inconsistencies associated with manual drilling. As the manufacturing requirements of the Aerospace industry lead to greater flexibility and cost reduction, the limitations of the machine tool and robotic technology become more exposed. A lightweight, mobile/portable, modular and accurate PKM provides a revolutionary solution for many applications, while paving the way for a paradigm shift in manufacturing.
Neumann, Karl-Erik
Automated Riveting of C-130J Aft Fuselage Panels2017-01-20759/19/2017
Electroimpact and Lockheed Martin have developed an automated drilling and fastening system for C-130J aft fuselage panels. Numerous design and manufacturing challenges were addressed to incorporate the system into Lockheed Martin’s existing manufacturing paradigm and to adapt Electroimpact’s existing line of riveting machines for manufacture of these legacy aircraft parts. Challenges to automation included design of a very long yet sufficiently rigid and lightweight offset riveting anvil for fastening around deep circumferential frames, automated feeding of very short, “square” rivets in which the length is similar to the head diameter, creation of part programs and simulation models for legacy parts with no existing 3d manufacturing data, and crash protection for the aircraft part from machine collisions, given the uncertainties inherent in the model and the unique geometry of the aircraft parts. Additional challenges were overcome in integrating the system into Lockheed Martin’s existing manufacturing methodology, while avoiding disruption to ongoing production activity and delivery schedules. Innovative and novel solutions to all of these problems were found and implemented. The result is successful automation of the drilling and riveting work on the aft fuselage, with corresponding improvements in manufacturing quality and production cost, and development of new technology that will have application in future automation systems.
Bigoney, Burton, Huddleston, Nicholas
CPAC Bulkhead Riveting System2017-01-20749/19/2017
Ever increasing process applications inspire us, as suppliers of aircraft, structural-assembly, and equipment to design innovative and modular, manufacturing cells in compliance with modern specifications. The result is the new flexible C-Frame Panel Assembly Cell (CPAC) Bulkhead riveting System. This paper describes how benchmarks for flexible automated drilling and fastening are being achieved with the CPAC.
Dillhoefer, Thorsten, Erdinc, Fatih
Solid Lubricant Assisted Machining -An Environmental Friendly Clean Technology to Improve the Surface Quality2017-28-19647/10/2017
Machining of materials has received significant consideration due to the increasing use of machining processes in various industrial applications. In machining, the heat generated in the cutting zone during machining is critical in deciding the work piece quality. Lubricants are widely used to reduce the heat generation. Their usage poses threat to environment and health hazards. Hence, there is a need to identify eco-friendly and user-friendly alternatives to conventional cutting fluids. Modern tribology has facilitated the use of solid lubricants such as graphite, calcium fluoride, molybdenum disulphide, and boric acid as an alternative to cutting fluids in machining. Solid lubricant assisted machining is an environmental friendly clean technology for improving the surface quality of the machined work piece. The present work investigates the role of solid lubricant assisted machining with graphite lubricants on surface quality while machining EN 8 steel .The performance of solid lubricant assisted machining has been studied in comparison with that of wet machining. The results indicate that there is a considerable improvement in the process performance with solid lubricant assisted machining as compared to that of machining with cutting fluids. Results show considerable improvement in the surface finish with the use of solid lubricants. Due to the presence of solid lubricants, there is a decrease of surface roughness as compared to dry hard turning.
Ramamoorthy, Rajaganesh, Venkatesan, T., Rajendran, R.
Effect of Cryogenic Treatment of Copper Electrode on Electro-Discharge Machining2017-28-19627/10/2017
Cryogenic treatment is an ultra low temperature treatment technique. Effect of cryogenic treatment on properties of ferrous materials and alloys is well understood. Due to which, cryogenic treated materials are being used in various applications. One among them is Electro-Discharge Machining (EDM). In EDM, the replica of electrode is obtained on the work piece, during the process tool also worn out to certain extent. In order to reduce the tool wear rate cryogenic treatment can be applied to the tool material. In this paper, the effect of cryogenic treatment on electrode wear rate of electro-discharge machining for varied pulse ON time (EDM) was studied. The cryogenic treatment was applied to the copper electrode and the microstructure analysis was carried out using optical microscope. EDM experiment was conducted using untreated and cryogenic treated copper as electrode and High Speed Steel (HSS) as work piece. Electrical resistivity was also measured. From the microstructure analysis it was inferred that the grains of cryogenic treated electrode are smaller than that of the untreated sample. Electrode Wear Rate (EWR) was found to be reduced and Material Removal Rate (MRR) was improved due to cryogenic treatment. This can be related to the reduction in electrical resistivity of cryogenic treated copper electrode.
Mouda, Pervaz Ahmed, Siddhi Jailani, H
Adding Simple Vision Systems to Collaborative RobotsTBMG-270766/1/2017
Adding vision to a collaborative robot can open a world of possibilities for automation applications. With a vision system, a robot can inspect parts, check specific features of a part, recognize a part to pick it up, count items, adjust its path using visual feedback, color sort, and so on. The breadth of applications requires careful consideration to ensure selection of the right technology for the job.
Open Core Engineering: New Freedom for Machine Automation ProgrammingTBMG-267174/1/2017
The increasing sophistication and complexity of medical devices is compounded by strict regulatory requirements that demand systems that can produce consistent, repeatable results. Automation has been key to achieving these goals while maximizing output and minimizing downtime.
Artifact Based Assessment of CNC Machine Thermal Growth and Compensation2017-01-02993/28/2017
Thermal growth of spindle and other components is common in CNC machines, especially with MQL machining, and directly impacts positioning accuracy and thereby quality. A common method to address this is by measuring the thermal growth using gage bore probing and then compensating for it. Application of this method in 5-axis CNC machines is relatively new and effectiveness is often not tested. Error sources due to various orientations of the part could arise. A new artifact based method is presented for assessment of thermal compensation used by the CNC OEM. The method involves an artifact, test cycle and automated data logging. A precision granite artifact with gage bores on different faces is fabricated and can be presented for probing in different orientations. The machine is warmed up using repeated dry-cycling, thereby creating thermal growth. Compensation error is evaluated as the difference of actual thermal growth and compensation offset. Various metrics for overall compensation accuracy of the machine can then be evaluated. The artifact test is carried out on a 5-axis CNC machining center and compensation accuracy metrics evaluated.
Jalluri, Chandra, Rajoria, Himanshu, Goderis, Mark, Habel, Michael, Hill, Trevor
Machine Health Prediction Enhancement Using Machine Learning2017-01-16253/28/2017
Use of sensors to monitor dynamic performance of machine tools at Ford’s powertrain machining plants has proven to be effective. The traditional approach to convert sensor data to actionable intelligence consists of identifying single features from cycle based signatures and setting thresholds above acceptable performance limits based on trials. The thresholds are used to discriminate between acceptable and unacceptable performance during each cycle and raise alarms if necessary. This approach requires a significant amount of resource & time intensive set up work up-front and considerable trial and error adjustments. The current state does not leverage patterns that might be discernible using multiple features simultaneously. This paper describes enhanced methods for processing the data using supervised and unsupervised machine learning methods. The objective of using these methods is to improve the prediction accuracy and reduce up-front set up. Classifiers such as KNN, Logistic Regression with Lasso, SVM for supervised learning and Novelty Detection, Elliptic Envelope for unsupervised learning have been compared using confusion matrices and ROC curves. The paper also highlights the challenges with applying supervised techniques due to lack of tagged data for training classifiers in a manufacturing environment.
Kalamdani, Rajeev, Jalluri, Chandra, Hermiller, Stephen, Clifton, Robert
Aerospace Hydraulics and Actuation Lessons LearnedAIR4543/1A (Current)2/23/2017
This SAE Aerospace Information Report (AIR) contains Lessons Learned from aerospace actuation, control and fluid power systems technologies. The lessons were prepared by engineers from the aerospace industry and government services as part of the work of SAE Committee A-6, Aerospace Actuation, Control and Fluid Power Systems. Each lesson was presented to the appropriate A-6 technical panel. The technical topics are organized into five sections covering systems, actuation, hydraulic components, electrical components and miscellaneous, each further divided into subsections. The information topics are presented in a concise format of Problem, Issue, Solution and Lesson Learned, often with accompanying descriptive diagrams and illustrations for clarity and understanding.
A-6 Aerospace Actuation, Control and Fluid Power Systems
Accelerating Abrasives with the Greatest Precision to Produce Intricate Medical ComponentsTBMG-2558410/1/2016
The latest medical developments typically involve smaller, more precise structures. These can be implants, assemblies, or components and motors in robotic equipment. With the demand for smaller parts, the requirements for producing these parts have become more challenging.
Impact of the Fourth Industrial Revolution to Complex Aerospace “CFRP/Ti Drilling Applications” in Conjunction with Advanced Cutting Tool Design and Electric ADU’s2016-01-20999/27/2016
On CNC Machines, drilling holes under perfect condition is possible. For drilling holes into titanium, composite and aluminum stacked materials the specific cutting condition can be selected. Furthermore surrounding conditions such as peck cycle, MQL and force and torque monitoring can be easily adapted. When drilling holes in the final assembly, CNC machine tools cannot be employed due to sizes and accessibility. Power Feed Units or Automated Drill Units ADUs are very handy, flexible and depending upon the jig extremely rigid. Whenever a machine tool does not fit, ADUs are highly recommended. In comparison to machine tools, conventional pneumatic ADUs can be used with one fixed set of feed, speed and micro peck only. Due to that a compromise in cutting condition has to be chosen in drilling stacked material with different layers. In the mind-set of the fourth industrial revolution, this article presents a completely new approach in the ADU Technology, while the benefits in the capability of CNC machine tools are now available on ADUs likewise. The benefits of using individual cutting condition for every layer in composite/metal stacked material, the worldwide online-process and -data monitoring, the improved tool-management and traceability, the remote diagnostic and improved cutting tool development functions will show a variety of extremely useful and new features.
Mueller-Hummel, Peter, Langhorst, Thomas
Accuracy Analysis and Error Source Identification for Optimization of Robot Based Machining Systems for Aerospace Production2016-01-21379/27/2016
Strong market growth, upcoming global competition and the impact of customer-requirements in aerospace industry demand for more productive, flexible and cost-effective machining systems. Industrial robots have already demonstrated their advantages in smart and efficient production in a wide field of applications and industries. However, their use for machining of structural aircraft components is still obstructed by the disadvantage of low absolute accuracy and adverse reaction to process loads. This publication demonstrates and investigates different methods for performance assessment and optimization of robot-based machining systems. For conventional Cartesian CNC machining systems several methods and guidelines for performance assessment and error identification are available. Due to the attributes of a common 6-axis-robot serial kinematics these methods of decoupled and separated analysis fail, especially concerning optimization of the system. One main focus of this paper lies on a new performance assessment strategy that in contrast to conventional methods neither needs a machining process nor an additional measurement system. Nevertheless it can be combined with these methods to provide even better results. By plotting the robots encoder during movement, calculating the actual tool-position/orientation and visualizing the hypothetic part manufactured a virtual machining process is elaborated. The effectiveness of this approach is demonstrated in combination with the robot optimization strategies “real-time guidance with LaserTracker” and “control parameter optimization”. The two optimization strategies themselves are the second main focus of the investigations presented.
Kothe, Simon, Stürmer, Sven Philipp von, Schmidt, Hans Christian, Boehlmann, Christian, Wollnack, Jörg, Hintze, Wolfgang
Development of Bicycle Surrogate for Bicyclist Pre-Collision System Evaluation2016-01-14474/5/2016
As part of active safety systems for reducing bicyclist fatalities and injuries, Bicyclist Pre-Collision System (BPCS), also known as Bicyclist Autonomous Emergency Braking System, is being studied currently by several vehicles manufactures. This paper describes the development of a surrogate bicyclist which includes a surrogate bicycle and a surrogate bicycle rider to support the development and evaluation of BPCS. The surrogate bicycle is designed to represent the visual and radar characteristics of real bicyclists in the United States. The size of bicycle surrogate mimics the 26 inch adult bicycle, which is the most popular adult bicycle sold in the US. The radar cross section (RCS) of the surrogate bicycle is designed based on RCS measurement of the real adult sized bicycles. The surrogate bicycle is constructed with detachable components with shatter resistant material to prevent structural damage during a collision, and matches the look and RCS of a real 26 inch mountain bicycle from all 360 degree angles. The surrogate bicycle rider is a 168 cm tall adult with CNC machined realistic body shape. The skin of the surrogate bicycle rider has the RCS of a real human skin. Combined skin with realistic body shape, the surrogate bicyclist has the RCS matching to that of a same sized real human from 360 degree angles in the view of 77GHz automotive radar. The surrogate bicyclist has articulated leg motion which is important for micro Doppler sensing and can be supported on a sled or a mobile carrier. It can be moved at a speed of 20 mph and can be collided by vehicles from any direction and be reassembled in less than 5 minutes.
Yi, Qiang, Chien, Stanley, Brink, Jason, Niu, Wensen, Li, Lingxi, Chen, Yaobin, Chen, Chi-Chen, Sherony, Rini, Takahashi, Hiroyuki
CAM Programming vs. Manual Programming in Medical MachiningTBMG-243794/1/2016
The manufacture of medical devices involves some of the most sophisticated machining processes found in industry today. From a machining perspective, the machine tools that make up the “back bone” of medical device machining are 5-axis Computer Numerical Control (CNC) Mills, Wire EDMs (Electrical Discharge Machining) and Swiss-type lathes. For years, computer aided manufacturing (CAM) software has been used to automate the programming of the first two of those machining operations: 5- axis CNC Mills and Wire EDMs. However, CNC Swiss have been slower to move CAM.
An Overview of Nitinol: Superelastic and Shape MemoryTBMG-2307710/1/2015
The world population is growing, globalization has resulted in a higher standard of living in many countries, and people are living longer. With increased living standards and choices people make, lifestyle-related illnesses, such as cardiovascular diseases, are on the increase. Companies race to make medical devices to cure challenging physical conditions and diseases. Novel materials are an integral part of supporting such design and development. One such material is Nitinol (NiTi), a serendipitous discovery in 1959 by William J. Buehler during research at the U.S. Naval Ordnance Laboratory, White Oak, MD. Nitinol, which saw use in medical devices beginning in the late 1980s, stands for Nickel Titanium Naval Ordnance Laboratory.
Integrated Ball-Screw Based Upset Process for Index Head Rivets Used in Wing Panel Assembly2015-01-24919/15/2015
A new high speed forming process for fatigue rated index head rivets used in wing panel assembly using ball-screw based servo squeeze actuation has been developed. The new process is achieved using a combination of force and position control and is capable of forming to 40,000 lbs at rates of up to 200,000 lbs/second whilst holding the part location to within +/− 10 thousandths of an inch. Multi-axis riveting machines often have positioning axes that are also used for fastener upset. It is often the case that while a CNC is used for positioning control, another secondary controller is used to perform the fastener upset. In the new process, it has been possible to combine the control of the upset process with the machine CNC, thus eliminating any separate controllers. The fastener upset force profile is controlled throughout the forming of the rivet by using a closed loop force control system that has a load cell mounted directly behind the stringer side forming tool. Panel assembly where the components are not pre-tacked is referred to as a ‘one-up’ process. This process requires that aircraft parts be rigidly and precisely fixtured, and that the fastening processes do not result in excessive part motion. The recently developed riveting process uses a separate position control loop and a position sensor to hold the location of the panel during rivet squeeze to within +/− 0.010″.
Haworth, Paul, Peterson, Donald, Hayes, Curtis
Utilizing Additive Manufacturing / 3-D Printing to Optimize Design and Support Solutions for One-Off Spares and Support Product RequirementsF-0071-2015-102015/5/2015
ABSTRACT Out-of-production aircraft continue to have demand for spare parts that are designed and fabricated with the tooling, processes and materials that were optimized during the high-rate production periods. Similarly, component repair and overhaul support equipment can require broaching, machining, electrical discharge machining (EDM), grinding and polishing and other techniques necessary to achieve reliable functionality of the system. In both cases the low production volume for these parts requires significant non-recurring set-up, tooling, and quality controls costs that affect the per-unit costs and lead times. The maturing technology of additive manufacturing and 3-D printing is now allowing companies to strategize around "growing parts" from a digital database and bypass the design paradigms and production costs inherited from historical manufacturing limitations. Engineers who understand the design freedom of additive manufacturing could leverage the capability and optimize support equipment functionality even further to increase maintainability and safety of usage. As additive materials continue to develop, more and more low-volume spare parts could be converted from traditional, production-driven designs to parts grown-when-needed.
Reilly, Thomas, Przano, Dominic
Kinematic Analysis of a 6DOF Gantry Machine2015-01-04974/14/2015
Gantry robots are mainly employed for applications requiring large workspace, with limited higher manipulability in one direction than the others. The Gantries offer very good mechanical stiffness and constant positioning accuracy, but low dexterity. Common gantries are CNC machines with three translational joints XYZ (3DOF) and usually with an attached wrist (+3DOF). The translational joints are used to move the tool in any position in the 3D workspace. The wrist is used to orient the tool by rotation about X, Y and Z axis. This standard kinematic structure (3T3R) produces a rectangular workspace. In this paper a full kinematic model for a 6DOF general CNC (gantry) machine is presented, along with the Jacobian matrix and singularity analysis. Using Denavit-Hartenberg convention, firstly, the general kinematic structure is presented, in order to assign frames at each link. The forward kinematic problem is solved using Maple 17 software. Differential kinematics describes the analytical relationship between the joint motion and the end-effector motion in terms of velocities, through the manipulator Jacobian matrix. The configuration at which the manipulator Jacobian matrix drops rank is called singular configuration. In this paper the Jacobian matrix is derived using the vector cross multiplication method. The singularity conditions are examined and validated. The fully reachable workspace is plotted with Matlab tools using specified joint limits. The presented solutions are expressed in parametric manner and can be used for analysis of the existing gantry type machine as well as a design tool for new machines.
Filiposka, Monika, Djuric, Ana M., ElMaraghy, Waguih
Precision Measurement and Inspection Ensure Quality of SLS Rocket PanelsTBMG-217844/1/2015
Reverse engineering and inspection software Verisurf Software Anaheim, CA 714-970-1683
A Comparison between Regular and Vibration-Assisted Drilling in CFRP/Ti6Al4V Stack2014-01-22369/16/2014
As aircraft programs currently ramp up, productivity of assembly processes needs to be improved while keeping quality, reliability and manufacturing cost requirements. Efficiency of the drilling process still remains an issue particularly in the case of CFRP/metal stacks: hot and long metallic chips are difficult to remove and often damage the surface of CFRP holes. Low frequency axial vibration drilling has been proposed to solve this issue. This innovative drilling process allows breaking up the metallic chips in such a way that jamming is avoided. This paper presents a case of CFRP/Ti6Al4V drilling on a CNC machine where productivity must be increased. A comparison is made between the current regular process and the MITIS drilling process. First the analysis and comparison method is presented. The current process is analyzed and its limits are highlighted. Then the vibration process is implemented and its performances are studied. Both processes are compared according to the following criteria: chip morphology, thrust force, power consumption, tool life, cycle time, holes quality and manufacturing costs. Results show that the vibration drilling process is more productive and reliable, while maintaining the quality as well as reducing manufacturing costs. The paper also shows that the vibration drilling allows simplifying cutting tool design and reducing lubrication.
Lonfier, Julian, De Castelbajac, Côme
A New Robotic Vibration-Drilling Process2014-01-22589/16/2014
In today's aircraft assembly process several new features make drilling operations very challenging according to production requirements. Parts are made of thin or thick multi-material stacks with a large scope to cover and complex assembly sequences. In addition, the current ramp-up in aircraft programs involves to improve productivity while keeping process quality and reliability. In this context robotic solution meets perfectly all these requirements as it is flexible, reconfigurable, fast and agile. Among the possible end-effectors, the Barrel Multi-Function End Effector (BMFEE) appears to be the most flexible solution to allow many different process configurations. The latest developments have been focused on the drilling equipment of this BMFEE. In fact the drilling process efficiency can be constantly improved especially in terms of reliability, quality and productivity. Therefore vibration-assisted drilling system has been integrated into the BMFEE drilling module. This innovative drilling process allows breaking up the metallic chips in such a way that jamming is avoided. Thus peck-drilling cycles are avoided and the global process offers more reliability and productivity while fulfilling quality requirements. This article presents the work of this integration. Benefits of this new robotic vibration-drilling process are shown on the basis of an industrial example.
Laporte, Sylvain, Gueydon, Etienne, Auffret, Alain, De Castelbajac, Cosme
Robot Accuracy: Online Compensation (EU COMET Project)2014-01-22579/16/2014
The 30 month COMET project aims to overcome the challenges facing European manufacturing industries by developing innovative machining systems that are flexible, reliable and predictable with an average of 30% cost efficiency savings in comparison to machine tools. From a conceptual point of view, industrial robot technology could provide an excellent base for machining being both flexible and cost efficient. However, industrial robots lack absolute positioning accuracy, are unable to reject disturbances in terms of process forces and lack reliable programming and simulation tools to ensure right first time machining, once production commences. These three critical limitations currently prevent the use of robots in typical machining applications. The COMET project is co-funded by the European Commission as part of the European Economic Recovery Plan (EERP) adopted in 2008. The EERP proposes the launch of Public-Private Partnerships (PPP) in three sectors, one of them being Factories of the Future (FoF). Factories of the Future is a EUR 1.2 billion program in which the European Commission and industry are collaborating in research to support the development and innovation of new enabling technologies for the EU manufacturing sector. The 14 project partners combine their experience and expertise in manufacturing from 8 countries across Europe to use plug-and-produce COmponents and METhods for adaptive control of industrial robots enabling high-end machining for cost effective, flexible and reliable manufacturing solutions.
Holden, Roger, Lightowler, Paul, Andreou, Simon
Selecting the Proper Motor for Linear Motion ApplicationsTBMG-204199/1/2014
Linear motion systems are found inside countless machines including precision laser cutting systems, laboratory automation equipment, semiconductor fabrication machines, CNC machines, factory automation, and many others too numerous to list. They range from the relatively simple such as an inexpensive seat actuator in a passenger vehicle, to a complex, multi-axis coordinate system complete with control and drive electronics for closed-loop positioning. No matter how simple or complex the linear motion system, at the most basic level, they all have one thing in common: moving a load through a linear distance in a specific amount of time.
Utilizing Selective Laser Sintering For Production Fabrication of Peculiar Support EquipmentF-0070-2014-95635/20/2014
Traditionally, helicopter peculiar support equipment is designed, developed, and fabricated using conventional methods, primarily with metallic materials. Specifically, component repair and overhaul tools containing unique, complex features (e.g. internal involute splines) are fabricated using conventional broaching, machining, or electrical discharge machining (EDM) techniques. These techniques combined with the low volume production and acquisition of these products, result in high cost and long lead times. As an alternative, Selective Laser Sintering (SLS), the process of using 3D CAD models to "grow" parts using a laser to sinter powdered material, can be utilized with the primary benefits being inherent cost savings and lead time reductions. This process also facilitates the ability to develop unique, innovative, and simpler tools that would have been impractical or impossible to fabricate using conventional methods. Feasibility, proofing, and practical implementations are the focus of this paper.
Przano, Dominic
CNC Technology Produces Precision ImplantsTBMG-192273/1/2014
Substantial legal requirements result in complex functional specifications for implant manufacturers. From the design, including materials, through production, the complete process chain must be documented and validated. Computer numerical controlled (CNC) high-tech machines support prosthetics manufacturers and allow highquality products to be manufactured, despite continuing high cost pressures.
Mobile Automated Robotic Drilling, Inspection, and Fastening2013-01-23389/17/2013
The versatility of the accurate robot has been increased by coupling it with a mobile platform with vertical axis. The automation can be presented to fixed aircraft components such as wings, fuselage sections, flaps, or other aircraft assemblies requiring accurate drilling, inspection, and fastening. The platform accommodates a tool changer, ride along coupon stand, fastener feed system, and other systems critical for quality automated aircraft assembly. The accurate robot's flexibility is increased by a floor resynchronization system. The indexing system is replaced by an automated two-camera onboard vision system and miniature targets embedded in the factory floor, with accuracy comparable to cup and cone alternatives. The accurate robot can be deployed by casters, curvilinear rail, or air bearings.
Gray, Troy, Orf, Daniel, Adams, Greg
Increasing Machine Accuracy by Spatially Compensating Large Scale Machines for Use in Constructing Aerospace Structures2013-01-22989/17/2013
Starting in 2003 Electroimpact began development on a comprehensive kinematic and compensation software package for machines with large envelopes. The software was first implemented on Electroimpact's Automatic Fiber Placement (AFP) equipment. Implementation became almost universal by 2005. By systematically collecting tracker measurements at various machine poses and then using this software to optimize the kinematic parameters of the machine, we are able to reliably achieve machine positional accuracy of approximately 2x the uncertainty of the measurements themselves. The goal of this paper is to document some of the features of this system and show the results of compensation in the hope that this method of machine compensation or similar versions will become mainstream.
Rudberg, Todd
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