Vision-guided process optimization for stringing reduction in FDM 3D printing using RSM Rajamani R, Aswin T M, Dhinnesh S, Guru Prasath K S, Hasina M Engineering Research Express, 2025 Fused Deposition Modeling (FDM) often faces problems in the quality of the parts due to formation of defects such as stringing, dimensional inaccuracy and warping. Stringing is a defect in FDM, where tiny strings of plastic material exist on the printed objects. This study employs the Central Composite Design (CCD) approach under Response Surface Methodology (RSM) to conduct experimental trials, optimizing critical process parameters influencing stringing, which includes nozzle temperature, retraction speed, layer thickness and print speed. A vision-based defect identification approach is employed to detect and quantify the presence of stringing in printed parts. A regression model is developed to analyze the effect of process parameters on the formation of stringing. The optimal parameters were determined as nozzle temperature of 198 °C, retraction speed of 36 mm s−1, print speed of 145 mm s−1 and layer thickness of 0.14 mm. These findings are crucial for manufacturing industries where precision and reliability are vital. By addressing the stringing in FDM processes, this work enhances the quality of printed parts while reducing reliance on post-processing, thereby promoting broader industrial adoption of FDM technology.
Micro-milling cutting conditions influence on part geometrical accuracy, surface quality and tool wear in Ti-Grade-5 alloy Rajamani R, Leo Kumar S P Materials Research Express, 2025 This work focuses on analyzing the consequences of micro-milling process variables on part geometrical accuracy, area surface finish (Sa) and tool wear. Ti-Grade-5 (Ti-6Al-4V) was selected as the work material due to its established applications in biomedical micro parts and its potential for performance improvement. A tungsten carbide flat end two flute micro-milling cutter with a diameter of 500 μm was chosen as the cutting tool. A feed rate (fz) range of 0.2–0.3 μm tooth−1 was selected for the work material, taking into account the size effect. Other variables included a depth of cut (ac) ranging from 75 to 150 μm and cutting speed (vc) ranging from 23.55 to 70.65 m min−1. Taguchi L9 Orthogonal array-based micro-milling experiments were conducted using a unique micro-cutting tool. The response variables measured included tool wear, geometrical accuracy, and Sa values.The results indicate that operating at lower ranges of vc (23.55 m min−1), fz (0.2 μm tooth−1), and ac (75 μm) yields a geometrical accuracy of 33.334 μm, an Sa value of 0.185 μm, and minimal tool wear of 11 μm. It was observed that under these lower operating conditions, there is an increased time interval for material removal and reduced contact between the workpiece and the tool. In conclusion, optimizing cutting conditions based on the size effect will enhance part geometrical accuracy, surface finish, and tool performance during the micro-part generation process in Ti Grade-5 alloy.
A MACHINE VISION SYSTEM FOR INSPECTING MECHANICAL PARTS Rajamani Rajagounder Machine Graphics and Vision, 2025 Computer vision-based inspection has become widely used in manufacturing industries for part identification, dimensional inspection, and guiding material handling systems. Defect-free production cannot be achieved with sampling inspection methods; therefore, a 100 percentage inspection approach is mandatory to meet the zero-defect goals of manufacturing industries. Achieving this is possible with advanced technologies, such as vision-based inspection systems. In this study, a vision-based inspection system is proposed for part identification, defect detection, and dimensional measurement. The system is validated using machined parts, including a Druck plate, Pressure plate, and Retainer. A part identification algorithm is developed based on a geometry search approach. The inspection algorithm classifies parts based on edge relationships, utilizing edge detection techniques to identify each part's geometric features. Surface defects are identified by analyzing the pixel intensity gradients within defective regions. The system measures part dimensions using a vision system, with results comparable to those obtained from a coordinate measuring machine.
Impact of Excitation Frequency and Fill Levels on Fuel Sloshing in Automotive Tanks Rajamani Rajagounder, Jayakrishnan Nampoothiri Strojniski Vestnik Journal of Mechanical Engineering, 2025 Fuel sloshing in modern automotive fuel tanks is analyzed in this study to provide a better understanding of fuel system performance. The behaviour of sloshing waves was investigated under varying excitation frequencies and fuel fill levels using both experimental and numerical methods. A sinusoidal motion was applied to the fuel tank along its transverse axis, and the resulting wave profiles were captured using a digital camera setup. Numerical simulations were conducted using the volume of fluid (VOF) model and a user-defined function (UDF) in ANSYS Fluent to predict the sloshing wave profiles. The study reveals distinct wave patterns depending on the excitation frequency. Standing and traveling waves were observed at 0.5 Hz and 0.6 Hz, while multiple traveling waves with wave collisions occurred at 0.7 Hz. Additionally, increasing the fuel fill level (from 25 % to 60 % of tank height) significantly enhanced the damping of sloshing wave oscillations. Regression equations were developed to quantify the relationship between excitation frequency, fill level, and sloshing wave amplitude. These findings may contribute to the design of fuel tanks that mitigate sloshing effects and enhance overall vehicle performance.
Implementation of Six Sigma to improve service quality and customer satisfaction in e-commerce industry Kumar S Pratheesh, R Rajamani, P B Maharasi, R Mohanraj, K Morsshini, Prabhu M Nitis, V Pachaiyappan Recent Advances in Materials Manufacturing and Machine Learning, 2024 The internet has changed the language of e-commerce transactions for clients towards the purchase and selling of products and services during last decade. Sales in the e-commerce industry have been drastically increased as a result of internet’s rapid growth and these figures continue to rise year by year. As sales expands, the issues associated with the e-commerce industry also increases. The goal of this review paper is to identify the key challenges in the e-commerce industry and give appropriate solutions using various six sigma methodologies. This study presents a six-sigma improvement model based on DMAIC cycle that incorporates a set of statistical tools for quality improvement in e-commerce industry. Six major challenges in e-commerce industry such as delivery defects, delivery delays, customer complaints, cancellation, return, website and server errors were recognised and addressed. In each phase of the DMAIC cycle, appropriate tools such as project charter, pairwise ranking, cause and effect diagram, standard operating procedure, and reaction plan have been selected and used to overcome the aforementioned challenges. On comparing the various challenges with the help of pairwise ranking in measure phase, delivery defects which was ranked 1 with a maximum occurrence of five times turned out to be a primary concern in the e-commerce industry. The DMAIC tool implementation described in this paper can be applied to e-commerce as well as other service industries for product and service quality improvement, process improvement, cost reduction, capital profitability, and customer satisfaction.
IoT-enabled Condition Monitoring and Intelligent Maintenance System for Machine R. Mohanraj, R. Rajamani, S. Elangovan, S. Pratheesh Kumar, T.G. Sreekanth, C.S. Ramshankar, R. Sugumar Futuristic Manufacturing Perpetual Advancement and Research Challenges, 2023 Internet of Things (IoT) for industrial automation system is an innovative approach for remote monitoring of machine components and its processes. Condition monitoring of machines through traditional methods requires manpower, consumes time, and interprets the production process. This empathizes the need for remote monitoring of machine using IoT system. Real-time data monitoring of computer numerical control (CNC) turning center machine are important to increase the productivity. Real-time data of machine were collected from the various external sensors and programmable logic controller (PLC) system which has been connected to gateway through data acquisition board for condition monitoring. IoT system was directly connected with individual devices as well as with the control panel of the system to retrieve data. The data collected meaningfully was interpreted and analyzed by PTC ThingWorx IoT platform. The image target-based augmented reality virtual environment was created for real-time data visualization. This provides a provision for the manufacturer to monitor the condition of the system and to identify the device failure within the system. In the proposed IoT-enabled maintenance system, the overall equipment effectiveness (OEE) and theoretical tool life are visualized in real-time manner from the remote place.
A study of liquid sloshing in an automotive fuel tank under uniform acceleration Rajamani Rajagounder, Guru Vignesh Mohanasundaram, Prakasan Kalakkath Engineering Journal, 2016 This paper presents the free surface behaviour of liquid in a partially filled automotive fuel tank under uniformly accelerated motion. The liquid in the fuel tank is subjected to violent sloshing during sudden acceleration or stopping of the vehicle which will produce structural vibration and noise in the passenger compartment. To reduce this sloshing, baffles are used inside the tank. The objective of this work is to study the influence of vertical baffles and fill levels on free surface elevation of liquid in a partially filled fuel tank. The simulation of liquid free surface behaviour under uniform acceleration is done using ANSYS-FLUENT software. A numerical model is developed based on Volume of Fluid (VOF) technique to track the free surface motion of liquid. The explicit time discretization scheme is employed to solve the volume fraction equation. From the numerical analysis, amplitude of free surface elevation and slope of free surface are predicted. Experiments are carried out with transparent fuel tank, fabricated using glass fibre and epoxy resin. A uniform acceleration is applied to the tank and free surface displacements of liquid are captured using high speed camera. Also, an analytical model is formulated to find position of the free surface of liquid in a rectangular container subjected to uniform acceleration. The free surface profiles obtained from the simulations are compared with the experimental results.
Experimental and numerical analysis of modal properties for automotive fuel tank Arpn Journal of Engineering and Applied Sciences, 2014
Inspection and error analysis of Geneva gear on machine vision system using Sherlock™ and VB 6.0 Algorithm C. Vigneswaran, M. Madhu, R. Rajamani 2012 International Conference on Machine Vision and Image Processing Mvip 2012, 2012 Indexing mechanisms find several applications in machineries, equipments and instruments such as, watches, projectors, machine tools, printing and pressing machinery, packaging and automatic machinery, etc., Currently, Geneva mechanism is extensively used for this purpose due to its reduction in shock loading. Therefore, Geneva mechanism should be carefully designed and those attained dimensions inclusive of tolerances must be measured closely to the true value. These measurements need more than one measuring instrument, which cumulatively costs much. Machine Vision is the suitable remedial solution, which acts fast and reduces the cost for large quantity measurement. In this work, an updated version of analyzer is developed by collaborating Machine vision software with Visual Basic 6.0 to make easy and comfortable, even the user is not fully aware of machine vision operations. The Geneva wheel is designed and modeled using CAD software, the dimensional features of the component is compared with the original modeled CAD image, taken as template. For this, a machine Vision software named Sherlock™ is interfaced with Visual Basic 6.0 designed window. This window is customized for user friendly environment to facilitate even an unskilled operator to operate the inspection system without having a deep knowledge about Machine Vision and its software's.
