- T. Narendra Reddy
- S. N. Vithun
- Mervin Herbert
- Shrikantha S. Rao
- M. Girish Kumar
- P. V. Shashikumar
- C. Rajesh Kumar
- V. Shanmugaraj
- Ranga Komanduri
- Prahalad Rao
- Omer Beyca
- Sanjay Jagannath
- Adam Fields
- Zhenyu Kong
- Satish Bukkapatnam
- J. Ramachandra Kiran
- S. Gopi Krishna
- P. V. Shashi Kumar
- K. M. Muhammed Nabil
- P. Hare Prasaad
- S. Senthil Kumar
- S. Thangavel
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z All
Vinod, Prakash
- A Compact XY Flexure-Based Nanopositioning Stage for Scanning Probe Microscope (SPM)
Authors
1 Nano Manufacturning Technology Centre (NMTC), CMTI, Bengaluru, IN
2 Nano Manufacturning Technology Centre (NMTC), CMTI, Bengaluru, IS
3 Mechanical Engineering, National Institute of Technology Karnataka (NITK), Surathkal, IN
Source
Manufacturing Technology Today, Vol 15, No 10 (2016), Pagination: 3-8Abstract
Nanotechnology has been growing rapidly in most of the applications related to semi-conductor devices, health care, consumer goods, medicine and bio-technology. Nanopositioning systems are the sub-systems of nanotechnology equipments such as nanofabrication, nano-measurements and optical focusing systems. This paper is mainly focused on the development of compact XY flexure based mechanism for Scanning Probe Microscopes (SPM). The work includes design, manufacturing and testing of flexure based nanopositioning system. The developed nano-positioning stage is tested in open-loop operation for linearity and cross axis motions of the compliant mechanism. The sources of motion errors in a nanopositioning system include actuator non-linearity, creep, structural vibrations of flexure mechanism and thermal drift are minimized using closed loop operation. The compact XY system has been tested for dynamic motion and the measured bandwidth of the positioning system shows that it can be used for scanning probe microscope (SPM) application.Keywords
Compliant Mechanism, Flexure, Nano-Positioning System, Piezo-Based Systems, Capacitive Sensors, Closed Loop System.- A Study on Ground Vibrations Induced by Metro Train Movement
Authors
1 Nano Manufacturing Technology Centre, Central Manufacturing Technology Institute, Bangalore, IN
Source
Manufacturing Technology Today, Vol 13, No 7 (2014), Pagination: 3-7Abstract
Nanotechnology deals with particles and system with dimensions of approximately 1 to 100 nanometers. The environment factors like ground vibration, temperature, humidity, acoustics, air velocity, Electro Magnetic Interference, Illumination and cleanliness will limit the performance of equipments used in nano manufacturing. Among all the environmental factors, ground vibration plays a major role in limiting the performance of the equipment. Some aspects of nanomanufacturing facilities like nanofabrication, nanometrology requires extremely stable environment with very stringent limits of ground vibration. This paper is focused on the study of vibrations induced by metro train movement. The study reveals that, the vibration induced by metro train is exceeding the limits as per the standard set by the National Institute of Standards and Technology (NIST).Keywords
Vibration, Rail, Nano Metrology, Nanotechnology, Nanomanufacturing.- On-Line Detection and Identification of Faults and Abnormalities in Sensors for Ultra Precision Process Monitoring
Authors
1 Central Manufacturing Technology Institute, Bangalore, IN
Source
Manufacturing Technology Today, Vol 13, No 7 (2014), Pagination: 13-19Abstract
In Ultra precision machining best results are obtained with on-line monitoring and adaptive control of various process parameters during machining. For a reliable on-line process monitoring and error compensation system, it is necessary to have accurate sensor readings. However, sometimes sensors may become faulty and due to failure it gives erroneous or constant values throughout the process. The problem of sensor validation is therefore a critical part of effective process monitoring. The objective of this study is to develop a sensor fault detection module which will be useful for different error compensation /diagnostic techniques needed for the ultra precision machine. A procedure based on Principal Component Analysis (PCA) is developed, which enables to perform detection and identification of sensor failures. PCA is a data driven modelling that transforms a set of correlated variables into a smaller set of new variables (principal components) that are uncorrelated and retain most of the original information. This new index is proposed in order to detect simple and multiple faults affecting the process and diagnose abnormalities in the original system in a robust way. The PCA model maps the sensor variables into a lower dimensional space and tracks their behaviour using Hot teling T2 and Q statistics.Keywords
PCA, Scores, Faulty Sensor, HottelingT2, Artificial Drifts, Q Statistics.- Addressing the Environmental Challenges of Nanometrology Laboratories
Authors
1 Nano Manufacturing Technology Centre, CMTI, Bangalore, IN
Source
Manufacturing Technology Today, Vol 13, No 4 (2014), Pagination: 18-25Abstract
Nanometrology deals with measurements and analysis of dimensions of approximately 1 to 100 nanometres as well as measurement of force, electrical, magnetic and optical properties and to correlate the measured size with properties. Some aspects of this work require extremely stable environments. Very stringent limits are often required on environmental vibration and noise, temperature, EMC, Illumination and Clean Room requirements. The environmental requirements of Nanometrology from the perspective of designing of an advanced Nanometrology laboratory are studied and reviewed in this paper. A desirable environment at a site may be adversely affected by ground vibration from a variety of sources such as road traffic, metro train movements, utility plants and the construction. The environment inside the lab is also affected by temperature fluctuation, humidity, acoustics disturbances, air velocity, EMC, Illumination and cleanliness. All these factors affect the nano level measurements. This paper addresses various environmental conditions, its potential effect on nano level measurements and environmental conditions to be maintained for a nano metrology laboratory.Keywords
Ground Vibration, Nano Metrology, Noise, Temperature, Humidity, Metro Train, EMI/EMC, Airflow, Cleanroom, Vibration Isolation.- On the Identification of Physical Sources of Vibration Sensor Signal Patterns in Chemical Mechanical Planarization (CMP) Process
Authors
1 School of Mech., & Aerospace Engg, Oklahoma State University, Stillwater, Oklahoma, US
2 School of Industrial Engg., & Management, Oklahoma State University, Stillwater, Oklahoma, US
3 Central Manufacturing Technology Institute, Bangalore, IN
4 Dept. of Mech. Engg., Indian Institute of Technology, Chennai, Tamil Nadu, IN
5 School of Industrial Engg., & Management, Oklahoma State University, Stillwater, Oklahoma, IN
Source
Manufacturing Technology Today, Vol 12, No 12 (2013), Pagination: 7-34Abstract
This document presents the battery of tests conducted to ascertain the physical sources of dominant vibration sensor signal patterns observed in chemical mechanical planarization (CMP) process. A Buehler (model Automet® 250) bench top CMP machine is instrumented with miniature MEMS 3-axis accelerometer (Analog Devices ADXL 335) and audio sensors (Analog Devices ADMP 401). The CMP setup is used for finishing blanket copper workpieces to a surface finish of Ra ~ 5 nm. While the sensor signals are sensitive to variations in the CMP process, the extraneous noise prevents the direct use of raw signal patterns for early detection of defects. Consequently, instead of primarily monitoring the raw sensor signal patters, we isolate signal features which are indicative of process state from those which are mere artifacts, and thus potentially valuable for process monitoring.
The frequency spectrum of typical MEMS vibration sensor signals acquired during the CMP process contains three dominant components, namely:
1. Low frequency component in the 0.5 - 1 Hz region.
2. Broadband frequency regions centered around 25 Hz and 50 Hz.
3. Broadband frequency region around 120 Hz.
A total of nine tests are reported to ascertain the underlying physical cause of each of these components. Component 1 is shown to result from eccentricity errors in the polishing head (spindle); component 2 is most likely a conjoined effect due to sensor characteristics, electromagnetic interference from machine elements, and structural vibration; component 3 is observed to respond to changing downforce (polishing load) conditions, and process state, such as pad wear, and as such is useful for process monitoring applications. In addition, a relatively small (-110 dB) background (white) noise is evident throughout the frequency spectrum of CMP vibration signals; this is explained as originating from measurement errors and environmental factors.
- A Study on Environmental Conditions for Nanometrology Labs
Authors
1 Micro Engineering and Nano Technology Dept, Central Manufacturing Technology Institute, Bangalore, IN
Source
Manufacturing Technology Today, Vol 12, No 1 (2013), Pagination: 12-21Abstract
Nanometrology deals with measurements and analysis of dimensions of approximately 1 to 100 nanometres. Some aspects of this work require extremely stable environments. Very stringent limits are often required on environmental vibration and noise, temperature, EMC, Illumination and Clean Room requirements. The environmental requirements of Nanometrology from the perspective of designing of an advanced Nanometrology laboratory are studied and reviewed in this paper. A desirable environment at a site may be adversely affected by ground vibration from a variety of sources such as vehicle traffic, rail, utility plants and the construction. The environment inside the lab may be also affected by temperature fluctuation, humidity, acoustics disturbances, air velocity, EMC, Illumination and cleanliness. All these factors affect the nano level measurements. This paper addresses various environmental conditions to be maintained for establishment of a nano metrology laboratory and its potential impact on nano level measurements.Keywords
Nano Metrology, Vibration, Noise, Temperature, Humidity, Traffic, Rail.- Design Considerations of Nanometer Resolution Aerostatic Spindle Bearing for Ultra Precision Machining
Authors
1 Micro-Engineering and Nanotechnology Department, Central Manufacturing Technology Institute, Bangalore, IN
Source
Manufacturing Technology Today, Vol 9, No 1 (2010), Pagination: 3-7Abstract
The paper addresses the key design considerations for aerostatic bearings for ultra precision machines requiring nanometer precise spindle rotation and moderate axial and radial stiffness. The development in optical & opto-electronic industry, defence, space and nuclear research demands for high form less than 0.1 μm and surface finish in the order of 2-5 nm components to be used as optics. Aerostatic bearing spindles with nanometric accuracy are required to manufacture such high precision optics. Many research and developmental work has been carried out for the past three decades in the field of aerostatic bearing design and performance testing. The selection of suitable bearing type and configuration plays a critical role in achieving the spindle running accuracy in nanometre range. This paper focuses on the selection criteria of bearing film thickness, air bearing types and configurations, air inlet feeding media, and the material selection. The errors associated with the aerostatic bearings and its effect on the surface finish and form accuracy of the component is also discussed in the paper. This gives a clear and basic insight to designers to begin with the aerostatic bearing spindle design for ultra precision machines.- Development of an Analytical Method for Dynamic Balancing of Rotors
Authors
1 MNT Dept., CMTI, Bangalore, IN
Source
Manufacturing Technology Today, Vol 8, No 11 (2009), Pagination: 3-8Abstract
Unbalance in rotating machinery is a common source of vibration in many applications and has a strong impact on the performance, accuracy of product and life of the rotating system. Generally, the dynamic balancing of rotors are carried out with the help of FFT Analyzer with expensive balancing software. Most of the commercially available balancing programs are not flexible, requires input like exact location o f the trial mass with respect to reference mark and do notallow intervention in between balancing procedure and in case of any mistake, the entire procedure need to be repeated. There are other methods for dynamic balancing like graphical method and trial and error method is cumbersome and prone to errors. This paper gives details on the development of an analytical method for dynamic balancing, which can be used with normal FFT Analyzer (with amplitude and Phase information). This method is inexpensive, easy to use, flexible and requires less time. This method provides correction mass and its angle with respect to the trial mass position. The developed analytical method has been validated by graphical method, experimental data and practical cases.- Theoretical and Experimental Study on Performance of Pneumatic Vibration Isolators for use in Ultraprecision Machine Tools
Authors
1 Central Manufacturing Technology Institute, Tumkur Road, Bangalore-560 022, IN
Source
Manufacturing Technology Today, Vol 2, No 12 (2003), Pagination: 17-22Abstract
Pneumatic Vibration isolators are used as vibration control devices in ultra precision machines / optical & instrumentation tables to cut off ground vibration efficiently. This helps in achieving surface roughness of a few nanometers on finished jobs on a ultraprecision machine. Unlike optical& instrumentation tables, in ultraprecision machines payload is high, with high moving loads. The static loads at various isolators of the isolation system also vary widely. During machining of jobs, the centre of gravity of machine will be shifting resulting in further change in load distribution of the isolator system. Experimental studies on the performance of different reputed make pneumatic vibration isolators on a ultraprecision machine has been carried out at CMTI to study various performance characteristics and to establish guidelines for selection and usage of pneumatic isolators in ultraprecision machines.- Study on the Influence of Spindle Running Accuracy and Feed Drive Characteristics of a Diamond Turning Machine on Work Piece Accuracy
Authors
1 Head-Nano Manufacturing Technology Centre Central Manufacturing Technology Institute Tumkur Road, Bangalore, IN
Source
Manufacturing Technology Today, Vol 18, No SP 3 (2019), Pagination: 42-46Abstract
Surface roughness of the order of few nanometers and form accuracies of the order of few hundred nanometers are the requirements of the components produced on a Diamond Turning Machine. Spindle running accuracies and feed drive characteristics of the machine are the significant factors, which are likely to limit the work piece accuracies that can be achieved on the machine.
The paper presents the studies conducted on the diamond turning machine, developed at CMTI using high precision integrated motor aerostatic spindle and hydrostatic slide driven by high precision friction drive, to establish the influence of the spindle error motions and feed drive errors of the linear axis on the work piece accuracy. The results show the correlation of various spindle errors and feed drive errors of the linear axis with the work piece errors.
Keywords
Single-Point Diamond Turning, Spindle Error, Feed Drive Error, Diamond Turning.References
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- Smart Factories – An Overview
Authors
1 Vellore Institute of Technology (VIT), Vellore, IN
2 Kongu Engineering College(KEC), Erode, IN
3 NMTC Dept., CMTI, Bengaluru, IN
Source
Manufacturing Technology Today, Vol 18, No 8 (2019), Pagination: 57-63Abstract
Due to the current structure of digital factory, it is necessary to build the smart factory to upgrade the manufacturing industry. This paper provides brief review on Smart factory and its implementation on traditional factory. They adopt the combination of physical technology and cyber technology and deeply integrate previously independent discrete systems making the involved technologies more complex and precise than they are now. Furthermore, a hierarchical architecture of the smart factory was proposed first, and then the key technologies were analyzed from the aspects of the physical resource layer, the network layer, and the data application layer. We have discussed the various features of the Smart Factory through an factory experts and example from the already existed smart factory. The Smart Factory architecture serves as solution pattern for the conception of modern production plants, which are characterized by mechatronic changeability, individualized mass production and internal and external networking. In addition, we discussed the major issues and potential solutions to key emerging technologies, such as Internet of Things (IoT), big data, and cloud computing, which are embedded in the manufacturing process. Finally, we discuss the main limitation of the Smart factory and its ongoing research towards overcoming the limitations toward the future.Keywords
Industry 4.0, Manufacturing Servitization, Industrial Big Data, Smart Factory, Real Time Factory, Internet Of Things, Cyber Physical System, Cyber-Physical System.References
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- Yoon, Soocheol; Um, Jumyung, Suh, Suk-Hwan; Stroud, Ian; Yoon, Joo-Sung: Smart Factory Information Service Bus (SIBUS) for manufacturing application: requirement, architecture and implementation. 'Journal of Intelligent Manufacturing', 2016 10.1007/s10845-016-1251-9.
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