Browsing by Author "Rao, N."

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An Integrated Method for Realtime 2D Hand Pose Detection
(Association for Computing Machinery, 2020) Rao, N.; Sinha, N.
We present an integrated, real-time approach for 2D hand pose detection from a monocular RGB image, with a common backbone shared between the bounding box detector and the keypoint detector subnets. This is in contrast to traditional methods which use two separate models for hand localization and keypoint detection with no sharing of features. We build on the popular RetinaNet architecture for object detection and introduce an integrated model which performs both hand localization and keypoint detection in real-time. We evaluate our approach on two different datasets and show evidence that our model obtains accurate results. Â© 2021 Owner/Author.
Investigation of errors in microcontroller interface circuit for mutual inductance sensor
(2019) Anarghya, A.; Rao, S.S.; Herbert, M.A.; Navin, Karanth, P.; Rao, N.
This paper proposes direct microcontroller interface circuit on Arduino platform, which is realized using the inductive sensors. The circuit is composed of two external resistors and two reference inductors resulting in four RL circuits. The microcontroller independently excites the two RL circuit on the primary side in order to measure the discharging time of voltage across each inductor. The discharging time of voltage across the inductors on the secondary side is measured similarly which is excited due to mutual inductance from the primary side. The technique of time-to-digital conversion from the built-in timer of microcontroller enables estimation of inductance value, which is compared with the actual value for self-inductance and mutual inductance circuits. Error analysis on the discharge time measurement are performed viz, parasitic resistance, parasitic capacitance on input output ports along with ringing effects and relative quantization error. The resistance and inductance estimation with regards to varying time period of oscillation of crystal is performed to analyze the effect of oscillation frequency on estimation. The parasitic resistance and quantization effects both contribute to the non-linearity errors (NLE) which is investigated further experimentally. The optimum value of the resistance was observed to be 120? and 60? for the primary and secondary side respectively. For primary side, the current and power consumption is 29 mA and 145 mW respectively, while for the secondary side, the current and power consumption is 27.5 mA and 137.5 mW respectively. The maximum NLE of ?0.18 %FSS and ?0.24 %FSS has been observed for an inductance range of 1 mH 10 mH along both primary and secondary sides respectively, whereas for an inductance range of 10 mH 100 mH, the NLE achieved was 0.29 %FSS and ?0.34 %FSS for the primary and secondary sides respectively. The future scope of the linear position displacement of the inductive sensor concludes the paper. 2018 Karabuk University
Investigation of errors in microcontroller interface circuit for mutual inductance sensor
(Elsevier B.V., 2019) Anarghya, A.; Rao, S.S.; Herbert, M.A.; Karanth P, P.N.; Rao, N.
This paper proposes direct microcontroller interface circuit on Arduino platform, which is realized using the inductive sensors. The circuit is composed of two external resistors and two reference inductors resulting in four RL circuits. The microcontroller independently excites the two RL circuit on the primary side in order to measure the discharging time of voltage across each inductor. The discharging time of voltage across the inductors on the secondary side is measured similarly which is excited due to mutual inductance from the primary side. The technique of time-to-digital conversion from the built-in timer of microcontroller enables estimation of inductance value, which is compared with the actual value for self-inductance and mutual inductance circuits. Error analysis on the discharge time measurement are performed viz, parasitic resistance, parasitic capacitance on input–output ports along with ringing effects and relative quantization error. The resistance and inductance estimation with regards to varying time period of oscillation of crystal is performed to analyze the effect of oscillation frequency on estimation. The parasitic resistance and quantization effects both contribute to the non-linearity errors (NLE) which is investigated further experimentally. The optimum value of the resistance was observed to be 120? and 60? for the primary and secondary side respectively. For primary side, the current and power consumption is 29 mA and 145 mW respectively, while for the secondary side, the current and power consumption is 27.5 mA and 137.5 mW respectively. The maximum NLE of ?0.18 %FSS and ?0.24 %FSS has been observed for an inductance range of 1 mH–10 mH along both primary and secondary sides respectively, whereas for an inductance range of 10 mH–100 mH, the NLE achieved was 0.29 %FSS and ?0.34 %FSS for the primary and secondary sides respectively. The future scope of the linear position displacement of the inductive sensor concludes the paper. © 2018 Karabuk University
Numerical investigation on wave transmission characteristics of perforated and non-perforated pile breakwater
(2019) Rao, N.; Suryanarayana, Barimar, Rao, P.; Nayak, K.; Kishor, Pal, S.; Hunasanahally, Sathyanarayana, A.; Suvarna, P.; Umesh, P.
Dock operations, harbouring and many other port activities demand tranquil water condition. This makes breakwater structures more than essential in coastal engineering applications. For zero wave action, rubble mound or vertical wall breakwaters are used, and for small docks and shores, piles can be used as efficient breakwaters. The permeability of pile breakwaters also aides in keeping the shores clean as there is water circulation and keeps the interferences caused due to littoral drift to the minimum. Numerical study on the single row pile breakwater is carried out using an open source computational fluid dynamics (CFD) software REEF3D. Interaction of waves with non-porous pile breakwater is simulated in a three-dimensional numerical wave tank using REEF3D and resulted transmission coefficient is validated using the physical model studies as reported by Subba Rao et al. (1999). Further, the efficiency of porous piles over non-porous piles is studied by simulating wave conditions by varying wave height, wave period, water depth and percentage porosity of the piles. It has been observed from the present study that porous piles are more efficient in wave attenuation compared to non-porous piles. The reason is that perforations increase turbulence during wave interaction which results in a better wave attenuation. � Published under licence by IOP Publishing Ltd.
Numerical investigation on wave transmission characteristics of perforated and non-perforated pile breakwater
(Institute of Physics Publishing helen.craven@iop.org, 2019) Rao, N.; Rao, P.; Nayak, K.; Kishor Pal, S.; Hunasanahally Sathyanarayana, A.; Suvarna, P.; Umesh, U.
Dock operations, harbouring and many other port activities demand tranquil water condition. This makes breakwater structures more than essential in coastal engineering applications. For zero wave action, rubble mound or vertical wall breakwaters are used, and for small docks and shores, piles can be used as efficient breakwaters. The permeability of pile breakwaters also aides in keeping the shores clean as there is water circulation and keeps the interferences caused due to littoral drift to the minimum. Numerical study on the single row pile breakwater is carried out using an open source computational fluid dynamics (CFD) software REEF3D. Interaction of waves with non-porous pile breakwater is simulated in a three-dimensional numerical wave tank using REEF3D and resulted transmission coefficient is validated using the physical model studies as reported by Subba Rao et al. (1999). Further, the efficiency of porous piles over non-porous piles is studied by simulating wave conditions by varying wave height, wave period, water depth and percentage porosity of the piles. It has been observed from the present study that porous piles are more efficient in wave attenuation compared to non-porous piles. The reason is that perforations increase turbulence during wave interaction which results in a better wave attenuation. Â© Published under licence by IOP Publishing Ltd.
Optimized ANN-GA and experimental analysis of the performance and combustion characteristics of HCCI engine
(2018) Anarghya, A.; Rao, N.; Nayak, N.; Tirpude, A.R.; Harshith, D.N.; Samarth, B.R.
HCCI (Homogeneous Charge Compression Ignition) engine has the benefit of operating at high thermal efficiency and low emissions of NOx and soot. However, it has challenges of complex combustion phase controlling and low operating range. This research work investigated the performance and combustion characteristics of HCCI engine with numerical simulations on ANSYS FLUENT and neural network models. The numerical and neural network results were validated by experimental observations with different fuel properties and reduced valve lifts for trapping of the exhaust gases. Experiments were performed on a SMART engine for different speeds and inlet air temperature, with various reference fuels (PRF30, PRF50, PRF70) and methanol to validate the CFD and ANN-GA observations. The engine performance was analyzed for IMEP, ISFC and thermal efficiency, which were found to be 8.2 bar, 205 g/kWh and 44.5% respectively as the optimum performance with PRF-70 fuel. The trapping of the residual gases was performed with various fuel blends in order to overcome the cyclic variations and to improve the operating zones near the knock boundary. The heat release rate was significantly reduced with trapped exhaust gases, and operating region was improved with the use of methanol fuel. Overall the trapping of the hot residual gases resulted in the maximum increase in the operating region by 12% and reduced cyclic variations by 15% for methanol fuel. The exhaust emissions were analyzed and ultra-low emissions of NOx at lean operating conditions were observed with the reduced valve lifts. The study results indicated thermal NO emissions on an average were decreased by 7.8%, CO emissions reduced by 6% and HC emissions increased by 9%. Methanol had ultra-low emissions of HC and CO, but higher emissions of NO and PRF30 had lower emissions of NO. However, ANN-GA model gave satisfactory combustion characteristics and emissions with respect to experimental results. Thus, CFD simulations, Neural Network methods and experimental study gave valuable thoughts of trapped residual gases approach on performance, combustion and emission characteristics of HCCI with PRF's and methanol fuel. 2017 Elsevier Ltd
Optimized ANN-GA and experimental analysis of the performance and combustion characteristics of HCCI engine
(Elsevier Ltd, 2018) Anarghya, A.; Rao, N.; Nayak, N.S.; Tirpude, A.R.; Harshith, D.N.; Samarth, B.R.
HCCI (Homogeneous Charge Compression Ignition) engine has the benefit of operating at high thermal efficiency and low emissions of NOx and soot. However, it has challenges of complex combustion phase controlling and low operating range. This research work investigated the performance and combustion characteristics of HCCI engine with numerical simulations on ANSYS FLUENT and neural network models. The numerical and neural network results were validated by experimental observations with different fuel properties and reduced valve lifts for trapping of the exhaust gases. Experiments were performed on a SMART engine for different speeds and inlet air temperature, with various reference fuels (PRF30, PRF50, PRF70) and methanol to validate the CFD and ANN-GA observations. The engine performance was analyzed for IMEP, ISFC and thermal efficiency, which were found to be 8.2 bar, 205 g/kWh and 44.5% respectively as the optimum performance with PRF-70 fuel. The trapping of the residual gases was performed with various fuel blends in order to overcome the cyclic variations and to improve the operating zones near the knock boundary. The heat release rate was significantly reduced with trapped exhaust gases, and operating region was improved with the use of methanol fuel. Overall the trapping of the hot residual gases resulted in the maximum increase in the operating region by 12% and reduced cyclic variations by 15% for methanol fuel. The exhaust emissions were analyzed and ultra-low emissions of NOx at lean operating conditions were observed with the reduced valve lifts. The study results indicated thermal NO emissions on an average were decreased by 7.8%, CO emissions reduced by 6% and HC emissions increased by 9%. Methanol had ultra-low emissions of HC and CO, but higher emissions of NO and PRF30 had lower emissions of NO. However, ANN-GA model gave satisfactory combustion characteristics and emissions with respect to experimental results. Thus, CFD simulations, Neural Network methods and experimental study gave valuable thoughts of trapped residual gases approach on performance, combustion and emission characteristics of HCCI with PRF's and methanol fuel. © 2017 Elsevier Ltd
Remotely operated marine rescue vehicle
(American Institute of Physics Inc. subs@aip.org, 2020) Shetty, N.B.; Rao, N.; Umesh, P.; Gangadharan, K.V.
Drowning is the process of experiencing respiratory impairment from submersion or immersion in liquid which leads to death, permanent or temporary disability. People living close to the water bodies or involved in water related activities are prone to drowning. When a victim is identified to be drowning, the first response would be to bring him out of water at the earliest. The urgency of the situation causes lifeguards and rescue personnel to put themselves at risk to save the victim. Provided early buoyancy, victims in distress are presented with a chance of keeping afloat until assistance arrives. Lifesaving equipment's such as ring-buoys (life-buoys) are purpose-designed to provide flotation. By using a low-cost drone to act as a flotation device the risk of drowning may be lowered for both the victim as well as for the rescuer. This drone or robot must be easy to deploy, light weight, reliable, low cost and capable to carry average person to safety. The proposed product is a modified ring buoy controlled by a remote. The ring buoy size is standard SOLAS (Safety Of Life At Sea) approved, which has been proved to work under extreme sea conditions. The external attachment consists of underwater thruster for propulsion and watertight container containing electronics and battery. The ground station includes operator with transmitter and micro-controller. The project on full implementation aims to have major impact in reducing risks involved in saving drowning people and in aiding the population dwelling by the water bodies in their daily occupational activities. Â© 2020 Author(s).
Thrust and torque force analysis in the drilling of aramid fibre-reinforced composite laminates using RSM and MLPNN-GA
(2018) Anarghya, A.; Harshith, D.N.; Rao, N.; Nayak, N.S.; Gurumurthy, B.M.; Abhishek, V.N.; Patil, I.G.S.
Aramid Fibre Reinforced Plastic composites are difficult to be drilled due to anisotropic material properties. Currently, soft computing techniques are used as alternatives to conventional mathematical models, which is robust and can deal with inaccuracy and uncertainty. In this paper, drilling of Aramid Fibre Reinforced Plastics (AFRPs) was carried out using Taguchi L54 experimental layout. Drilling tool used in this experiment was solid carbide. The purpose of this study was to find optimum combination of drilling parameters to obtain minimum thrust and torque force to reduce the delamination. Also, this paper proposed a prediction model of Multilayer Perception Neural Network optimized by Genetic Algorithm (MLPNN-GA). Moreover, RSM technique was used to evaluate the influence of process parameters (spindle speed, feed rate, drill point angle and drill diameter on thrust force and torque. The prediction capability of both RSM and MLPNN-GA was compared with Response optimizer for thrust force and torque. The investigation demonstrated that drill point angle is the primary factor affecting thrust force and drill diameter influences the torque force on the drill bit. Overall, this study recommends the use of high speed and low feed combination and drill point angles of 90 118 to reduce the delamination of the materials in the drilling of AFRP composites. 2018 The Authors
Thrust and torque force analysis in the drilling of aramid fibre-reinforced composite laminates using RSM and MLPNN-GA
(Elsevier Ltd, 2018) Anarghya, A.; Harshith, D.N.; Rao, N.; Nayak, N.S.; Gurumurthy, B.M.; Abhishek, V.N.; Patil, I.G.S.
Aramid Fibre Reinforced Plastic composites are difficult to be drilled due to anisotropic material properties. Currently, soft computing techniques are used as alternatives to conventional mathematical models, which is robust and can deal with inaccuracy and uncertainty. In this paper, drilling of Aramid Fibre Reinforced Plastics (AFRPs) was carried out using Taguchi L54 experimental layout. Drilling tool used in this experiment was solid carbide. The purpose of this study was to find optimum combination of drilling parameters to obtain minimum thrust and torque force to reduce the delamination. Also, this paper proposed a prediction model of Multilayer Perception Neural Network optimized by Genetic Algorithm (MLPNN-GA). Moreover, RSM technique was used to evaluate the influence of process parameters (spindle speed, feed rate, drill point angle and drill diameter on thrust force and torque. The prediction capability of both RSM and MLPNN-GA was compared with Response optimizer for thrust force and torque. The investigation demonstrated that drill point angle is the primary factor affecting thrust force and drill diameter influences the torque force on the drill bit. Overall, this study recommends the use of high speed and low feed combination and drill point angles of 90°–118° to reduce the delamination of the materials in the drilling of AFRP composites. © 2018 The Authors