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Browsing by Author "Shewale, Mahesh S."
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Item A Control Oriented Soot Prediction Model for Diesel Engines Using an Integrated Approach(American Society of Mechanical Engineers, 2021-11-01) Shewale, Mahesh S.; Razban, Ali; Mechanical Engineering, School of Engineering and TechnologyDiesel engines have been used in many vehicles and power generation units since a long time due to their less fuel consumption and high trustworthiness. With reference to upcoming emission norms, various engine out emissions have proved to be causing adverse effect on human health and environment. Soot, or particulate matter is one of the major pollutants in diesel engine out emissions and causes various lung related issues. There have been efforts to reduce the amount of soot generated using after-treatment devices like diesel particulate filter (DPF) to filter out particles and get clean tailpipe emissions. These technologies increase load on the system and involves additional maintenance. Also, deposition-based soot sensors have been found to be inoperative in certain scenarios like cold start conditions. In this research work, an effort has been made to develop a phenomenological model that predicts soot mass generated in a Cummins 6.7L diesel engine. The model uses in-cylinder conditions such as pressure, bulk mean temperature, fuel mass flow rate and injector orifice diameter. The difference between soot mass formed and oxidized yields the net amount of soot generated at engine out end. Furthermore, the generated soot mass is compared with benchmark results for specific load conditions and appropriate controller is designed to minimize this tradeoff. The control parameter being used here is fuel rail pressure, which controls the lift-off length, and ultimately equivalence ratio, which predicts mass of soot, generated in formation phase. The presented method shows a prediction error ranging from 5–20%, which is significantly reduced to 2% using a PID controller. The approach presented in this research work is generic and can be operated as stand-alone system or an integrated subsystem in a higher order control architecture.Item Characterization and System Identification of XY Flexural Mechanism Using Double Parallelogram Manipulator for High Precision Scanning(Springer, 2020) Shewale, Mahesh S.; Razban, Ali; Deshmukh, Suhas P.; Mulik, Sharad S.; Patange, Abhishek D.; Mechanical and Energy Engineering, School of Engineering and TechnologyThis article represents modeling of double parallelogram flexural manipulator derived from basic classical mechanics theory. Fourth order vibration wave equation is used for mathematical modeling and its performance is determined for step input and sinusoidal forced input. Static characterization of DFM is carried out to determine stiffness and force deflection characteristics over the entire motion range and dynamic characteristics is carried out using Transient response and Frequency response. Transient response is determined using step input to DFM which gives system properties such as damping, rise time and settling time. These parameters are then compared with theoretical model presented previously. Frequency response of DFM system gives characteristics of system with different frequency inputs which is used for experimental modeling of DFM device. Here, Voice Coil Motor is used as Actuator and optical encoder is used for positioning sensing of motion stage. It is noted that theoretical model is having 5% accuracy with experimental results. To achieve better position and accuracy, PID and LQR (Linear Quadratic Regulator) implementation was carried out on experimental model. PID gains are optimally tuned by using Ziegler Nichols approach. PID control is implemented experimentally using dSPACE DS1104 microcontroller and Control Desk software. Experimentally, it is observed that positioning accuracy is less than 5 μm. Further multiple DFM blocks are arranged for developing XY flexural mechanism and static characterization was carried out on it. The comparison of experimental and FEA results for X-direction and Y-direction is presented at end of paper.Item Design and Experimental Validation of Voice Coil Motor for High Precision Applications(IEEE, 2018-04) Shewale, Mahesh S.; Razban, Ali; Deshmukh, Suhas P.; Mulik, Sharad S.; Zambare, Hrishikesh B.; Mechanical Engineering and Energy, School of Engineering and TechnologyFlexural structures are extensively beneficial when differentiated with conventional inflexible body structures where point accuracy positioning is strongly required extending in the range of microns. To fulfill clear and accurate positioning requirements, we come up with the solution of voice coil motors (VCM) with position estimator algorithm. Appropriate magnet and coil assembly is designed by considering the ultimate force for the application. Voice coil motor components are fabricated on milling machine and then assembled. This VCM is incorporated with dSPACE DS1104 R&D controller with the help of linear current amplifier (LCAM) which controls VCM with respect to desired amplitude and frequency. Displacement of coil of VCM is detected with respect to fixed magnet by using linear variable differential transformer (LVDT) which generates analog voltage signal in relation with motion of coil. Static characteristic such as stiffness is determined using force-deflection plot and dynamic characteristic like damping factor and frequency response are estimated with the help of transient response obtained by providing step input to the motor. Further, PID controller is implemented on this VCM and it is error observed is less than ±0.S microns.Item Design and Implementation of Position Estimator Algorithm on Voice Coil Motor(IEEE, 2018-04) Shewale, Mahesh S.; Razban, Ali; Deshmukh, Suhas P.; Mulik, Sharad S.; Zambare, Hrishikesh B.; Mechanical Engineering, School of Engineering and TechnologyVoice Coil Motors (VCMs) have been an inevitable element in the mechanisms that have been used for precise positioning in the applications like 3D printing., micro-stereolithography., etc. These voice coil motors translate in a linear direction and require a high accuracy position sensor that amounts for a major part in the budget. In this research work., an effort has been made to design and implement an algorithm that would predict the displacement of VCM and eliminate the need of high cost sensors. VCM was integrated with dSPACE DS1104 R&D controller via linear current amplifier (LCAM) which acts as a driver circuit for VCM. Sine input was given to VCM with various amplitude and frequency and the corresponding displacement is measured by using linear variable differential transformer (LVDT). The position estimator algorithm is also implemented at the same time on VCM and its output is compared with that of LVDT. It is observed that there is 97.8 % accuracy in between algorithm output and LVDT output. Further., PID controller is used in integration with the novel algorithm to minimize the error. The estimator algorithm is tested for various amplitudes and frequencies and it is found that it has a very good agreement of 99.2% with the actual displacement measured with the help of LVDT.