International Journal of Instrumentation Technology (7 papers in press)
An Intuitive Approach to Innovate a Low Cost Braille Embosser
by Dhiman Chowdhury, Mohammad Zakaria Haider, Mrinmoy Sarkar, Mustakim Refat, Kanak Datta, Dr. Shaikh Anowarul Fattah
Abstract: Braille printers are the most convenient way to emboss the texts on a Braille paper. But existing embossers are more than 100 times expensive than the normal printers. In this paper, an innovative design of a low cost Braille printer is presented. The design being not dependent on expensive tools is an efficient solution. In the proposed Braille system, major concentration is given to develop the actuators which emboss the impressions on the Braille paper to make dots to decode text language in Braille format. Unlike conventional mechanisms, gear DC motors are utilized to design efficient and inexpensive actuators. Additionally, the overall printing system involves cost efficiently designed inter-dependent components, such as customized printing software, wireless communication system, sensing mechanisms, and compact mechanical setup. Extensive testing under different conditions is carried out and it is found that the proposed design can provide satisfactory embossing performance at a very low cost.
Keywords: Actuator; Braille; communication; cost-effectiveness; efficient; embosser; intuitive; printer; sensor; software; visually impaired.
Programmable FPGA Based 32 Channel Transmitter for High Frame Rate Ultrasound Channel Excitation Applications
by Jean Rossario Raj, S.M.K. Rahman, Sneh Anand
Abstract: This paper describes the design and results of a Field Programmable Gate Array (FPGA) designed for ultrasound transient elastography transmitter. The high frame rate is achieved by multi-line transmission. The design is capable of achieving frame rates up to 8000 frames per second by excitation of all the channels simultaneously. The FPGA also generates the drive signals for the commonly available CMOS transmit pulsers for high voltage excitation of the ultrasound transducer. The FPGA is configured from a microcontroller using a parallel interface. The FPGA also generates the synchronization pulses for the receiver. The FPGA has a flexible design where parameters like ultrasound frequency, number of pulses per burst, pulse repetition frequency, and so on are programmed from the microcontroller. One FPGA caters for 32 channels and has a maximum frequency of operation of 8MHz. The novelty of this study is in the design and implementation of an open FPGA architecture for 32 channel high frame rate ultrasound application.
Keywords: FPGA; Multi Line Transmission; Ultrasound Scanner; Transient Elastography.
Detection of NQR signals using Wavelet Transform and Adaptive filters.
by Preeti Hemnani
Abstract: NQR signal processing method based on two adaptive filters techniques namely adaptive noise cancellation (ANC), Adaptive line enhancement (ALE) and wavelet transform are studied and it is shown that ALE is faster detection method with improved signal to noise ratio. Based on the 14N NQR signal observed from NaNO2, ALE seems to be easier and more reliable technique for NQR spectroscopy.
Keywords: NQR; NMR; Wavelets; ALE; ANC.
Determining Statistical Parameters of ADC Using Probability Based Histogram Method with Noise as Stimuli
by Bhawana Garg, Deepak Mishra
Abstract: This paper aims to the estimation of an Analog to Digital Converter (ADC) parameters using probability-based histogram method with white Gaussian noise as stimuli. ADC characterization based on this methodology is described and error in computing the code transition level with suggested corrective action is reported. Uncertainty in the computation of Effective Number of Bits (ENOB) is investigated and simulation results for an 8-bit ADC are presented and compared with other existing methods.
Keywords: Differential nonlinearity; ENOB; Gain; Histogram technique; Integral nonlinearity; White Gaussian noise.
A Novel Method for Mitigation of False Echo in Radar Based Positioning System in High Scattering Zone Application Areas
by Prabal Patra, Chitresh Kundu, Bipan Tudu, Rajib Bandyopadhyay, Punit Rathore
Abstract: Conventional radar systems are rugged but prone to false echoes from various surrounding metallic structures which are always present in the industrial site. This paper presents a methodology for false echo mitigation in radar-based positioning system which is suitable for industrial conditions, specifically at steel plants. It can be used in various positioning requirements of rail-borne vehicles like overhead cranes and coke oven machines. In this method, the Return Time of Flight (RTOF) technique is used to measure the distance between two nodes. The echo signal is a frequency shifted active return, for eliminating false echoes, thus enabling distance measurement with very high degree of precision and accuracy even in a scattering environment. This method eliminates the problem of false echoes which is present with conventional radar systems. Using this method, the distance between the stations can be accurately determined over a range of 500 meters with precision in millimetres.
Keywords: RTOF; Radar; Laser; False Echo; Positioning.
ENHANCED HOWLAND BASED CONSTANT CURRENT SOURCE FOR SOIL ECa MEASUREMENT
by Ritula Thakur, Babankumar Bansod
Abstract: In the present work, Enhanced Howland current source based Voltage Controlled Current Source (VCCS), used in four probe Wenner array technique to measure apparent electrical conductivity (ECa) of soil is reported. The distortion in the output signal is negligible and current is maintained constant. To check circuit reliability for constant current characteristics across varying standard load resistance, voltages were measured to calculate value of current, which was then compared with theoretically calculated value. The performance of proposed circuit was studied using TINA-TI software simulations and it was found that proposed source is capable of providing a constant current over the entire range of resistance (0.5Ω to 20kΩ) within very low frequency range; with an error less than 5%, and an average error of 0.9466%, which is within acceptable tolerance in present application.
Keywords: Enhanced Howland based current source; Voltage Controlled Current Source; Wenner Array; Soil Electrical Conductivity (ECa) measurement.
A Novel Frequency Shifted Active Radar for Local Position Measurement of Rail Borne Vehicles for Industrial Conditions
by Prabal Patra, Chitresh Kundu, Arunangshu Ghosh, Bipan Tudu, Rajib Bandyopadhyay, Punit Rathore
Abstract: This paper presents active radar based position measurement system for rail borne vehicles. Laser systems are more accurate but fail to perform well in the dusty environment and also due to erroneous alignment. Conventional radar systems are rugged but prone to false echoes from various surrounding metallic structures which are always present in the industrial site. This affects radar based system adversely and the range gets limited to $50$m. To overcome this drawback, an active radar based system with frequency shift has been designed and developed which is suitable for industrial conditions and is used in positioning requirements of rail borne vehicles. The proposed system measures distance using return time of flight (RTOF) method. The echo signal is an active signal, generated by the slave to measure distance with very high precision and accuracy. The distance between the stations can be accurately determined over a range of 300 meters using this method with the accuracy of $pm 50$mm.
Keywords: Radar; RTOF; Microstrip; Laser; Filter; Antenna.