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Design optimization of savonius vertical axis wind turbine using genetic algorithm
(UMT, Lahore, 2017) Saad Bin Ejaz
Energy is derived from the natural resources. Access to energy is a key pillar for human being. Sun light is considered to be the first and most abundant source of energy. Latter more forms of energy discovered and till now it is the important need of man’s life. Wind Energy is another form of natural energy. Using this energy to generate electricity, energy crisis can be reduced. The objective of this research is to optimized the Coefficient of Performance of Savonius Vertical Axis wind turbine. In current situation, the Coefficient of Performance of VAWT is very low. There is a large room of research still available to increase the Coefficient of Performance. The model is two blades Vertical Axis Wind Turbine. The objective of this work is to achieve an optimized Coefficient of Performance. The variables use for optimization is Overlap distance ranges from 0 to 60 mm with difference of 5 mm, Twist angle (φ) ranges from 0 to 120 degree with difference of 30 degree and Wind speed ranges from 4 m/s to 18 m/s. In this research, parametric analysis of wind turbine is performed for both cases. The mathematical techniques use optimization is Genetic Algorithm (GA). The whole work divided into two cases. In Case I, wind turbine is use Without Endplates while in case II, wind turbine is use With Endplates. This wind is use to design for small scale projects. This model turbine often harnesses more power than conventional turbine. The objective function of GA is Coefficient of Performance. From all the generations achieved with initial population, GA obtain the optimal solution. Based on the simulation performed and optimization via Genetic Algorithm, it is realized that for case I, at overlap distance of 0mm and twist angle (φ) of 60o, wind turbine’s coefficient of performance will be optimum at wind speed of 4 m/s i.e. 28.738 % and for Case II, at similar condition wind turbine’s coefficient of performance will be optimum i.e. 59.3 %
Performance characteristics of diesel engine with bi-fuel using jatropha oil
(UMT, Lahore, 2018) ZAIN ALI KHAN
The expanding world population is getting industrialized rapidly with time. This results in an increased number of vehicles and sources of power generation. The increasing consumption of oil and decreasing resources causes a significant increase in the oil prize. The interests in exploration of alternative fuels are increasing with the rising oil prize. The major question for particular application is that which fuel can used as alternative fuel and what percentage of this fuel can be replaced with gasoline. A combination of available fuel and alternative fuels is the most likely choice in many cases. Wider applications of alternative fuels depend on economic, technological, and infrastructural issues. Jatropha is a tropical herb and can be matured in a diverse soil with low to high rainfall. The plant produces seeds containing inedible oil and can be acknowledged as a second-generation biofuel plant. It may provide a chunk of the fuel supply in the transportation and energy sectors. In the present work, Jatropha oil was squeezed from the seeds acquired from authorized dealer and changed to biodiesel by transesterification process. The important physical & chemical attributes of biodiesel were tested. The comparison of these properties for biodiesel and diesel oil shows approximately similar attributes and hence biodiesel is found quite feasible for usage in diesel engine. The biodiesel from jatropha oil is used in a single cylinder, four stroke diesel engine without any alteration in engine architecture or fuel scheme. The performance aspects of the diesel engine are examined in multiple proportions of biodiesel and diesel oil. The torque, and brake power of diesel engine using a mixture of 10% biodiesel and 90% diesel oil (J10D90) are found comparable with the torque and brake power of engine run on pure diesel oil. The torque and brake power of engine decreases with increasing percentage of biodiesel in the mixture. Similarly, the brake specific fuel consumption of diesel engine using a mixture of 10% biodiesel and 90% diesel oil (J10D90) is found comparable with the brake specific fuel consumption of engine run on pure diesel oil. The brake specific fuel consumption of engine then increases rapidly with increasing percentage of biodiesel in the mixture. The biodiesel blend J10D90 has shown optimum performance of diesel engine than any other blend.
Design and fabrication of low cost composite filament winding machine
(UMT Lahore, 2018) S.MUTEEN-UD-DIN; MUHAMMAD AMMAR JAVED; SALMAN SAEED KHAN
The authors are going to design and fabricate low cost composites filament winding machine. Filament winding is a process of laying high degree of fibers for the manufacturing of hollow or majorly cylindrical products with high tensile strength. Filament winding process having the high strength and weight ratio and gives high degree of control over consistency and fiber orientation. The product which produced by this process can be having no need of further matching and labor factor is also less than other molding processes. The filament composite pipes are manufactured with the help of high power fiber and resin by using 2 axes filament winding machine. The purpose of designed and fabrication of filament winding machine for the fabrication of pipes and those specimens which having the round shape. The concept of lathe machine and wet winding method used to design this machine. In filament winding process a single-glass travelling is drawn through a bath of resin which is fixed on the threaded rod by the rotating mandrel. By this process regular winding and good finish is achieved.
Automation of a brush tufting machine using multi axis control system
(UMT Lahore, 2018) HAMZA ARIF; UMER MUNIR; MUHAMMAD AZEEM
Personal computer and motion card controllers are programmed to design a multi axis control system and present the method to control the interface and procedures. In this stepper motors are used with feedback function to achieve closed loop control and to improve accuracy of the system. This system not only has distinctive interface and simple operation but also has high accuracy and superior performance compared to manual methods.
Optimization of number and position of the clamps in sheet metals fixture
(UMT Lahore, 2018) ARSALAN FAZIL
The accuracy of manufacturing process is highly dependent on how well a workpiece is constrained in the fixture. A well constrained workpiece show minimum deformation during manufacturing process or application of load and workpiece will have high stiffness. Workpiece can be constrained by proper positioning of fixture elements. Most of research in fixture layout optimization is done on rigid bodies and some work has been done on sheet metals to find the optimum position of the fixture elements. But, the selection of number of clamps entirely depends on the expertise and knowledge of designer. Therefore, the research work to select automatically the initial numbers of clamps and their positions is fairly new. In this research; a methodology is devised to select the number of clamps automatically and then finding the optimum position of clamps even if the designer lacks in expertise to do so. The objective function of this research is to minimize total deformation normal to the plane of workpiece while keeping maximum deformation of individual nodes upto 2 mm. The proposed method consists of two stages; in first stage, the initial number of clamps is calculated. In second stage, initial number of clamps and their positions are optimized using genetic algorithm. The first stage involves two different methodologies namely maximum deformation method and means method. The edges of the workpiece are design edges because clamps are placed on the edges only. In maximum deformation method workpiece is divided into four quadrants and the node with maximum deformation in each quadrant is selected. Clamps are added at the edge near to the maximum deformation nodes in each quadrant and adding clamps on the edge near to maximum deformation nodes is continued until deformation becomes lower than 2 mm. In means method, procedure is the same as in maximum deformation method, but average deformation is measured in each quadrant instead of maximum deformation. Then a node is selected from each quadrant whose value is closer to the value of average deformation of respective quadrant. Then clamps are placed on the edge near to the average deformation values nodes till the value of maximum deformation becomes less than 2 mm. In second stage only one method is devised. In second stage, genetic algorithm is implemented on layouts. Genetic algorithm is used to optimize number and position of clamps therefore first genetic algorithm is used to optimize the number of clamps then it is used to optimize the position of clamps. Number and position of clamps are not optimized simultaneously because the computational load is significant. When the number of clamps are optimized only population is generated and processes like crossover and mutation are not implemented because of significant number of clamps. More clamps produce lengthy chromosomes which are cumbersome to handle and when crossover Is performed the resulting computations takes significant time to complete when number of candidates in population are also significant. Once the clamps are reduced to minimal numbers then second population is generated and crossover, mutation are implemented to diversify population for optimizing the position of remaining clamps. Different kinds of case studies are solved with the proposed methods in different scenarios to check the effectiveness of the proposed method. An experiment is also performed in which the proposed method is implemented on case study 1. This was done to compare the computational results with experimental results and verify the effectiveness of the methodology. The final results of the experiment fully justify the proposed method.
Fabrication and implementation of dual axis solar tracker in UMT
(UMT Lahore, 2018-06) Muhammad Abdullah Sheikh; Muhammad Hussnain; Hafiz Waleed Akram
Sun based energy is quick turning into an essential methods for sustainable power source asset. With sun tracking, it turns into possible to generate greater energy since the solar panel can maintain a perpendicular profile to the rays of the sun. This project discusses the design and construction of a prototype used for solar tracking that has a dual axis of freedom. The highlighted innovation of this project is that it works on dual axis of rotation but all the previous work done in Pakistan was on fixed axis. The initial cost of putting in place the tracking gadget is considerably excessive, there are less expensive choices that have been proposed after some time. The use of a highly portable, efficient solar tracker can be very useful to applications of the military, industrial, or residential variety. The tracker effectively tracks the sun and changes its position likewise to amplify the power yield. The design of a tracking system consists of sensors, microcontroller operated control circuits to drive Direct Current (DC) motors and gear- bearing arrangements with supports and mountings. Two equipped DC motors are utilized to move the sunlight based board or also named as solar panel so sun's bar can stay lined up with the solar panel.
Performance of flywheel energy storage on wind power generation
(UMT Lahore, 2018-06) Shahryar Majeed Siddiqui; Mahmood Akram; Mudassir Razzaq
There are several energy storage systems (e.g. compressed air battery, battery and supercapacitors etc.) which are widely used according to the desired requirements. This report deals with the Performance of Flywheel Energy Storage on Wind Power Generation. Flywheel energy storage system which cannot be considered as an energy source but this system has the ability to store energy, and this energy can further be utilized as backup. The apparatus consists of flywheel, vertical axis wind turbine and its electrical system which uses air energy as an input to the wind turbine and also rotates the flywheel, and flywheel stores this energy in the form of kinetic energy. In this report we are mainly going to focus the effect of flywheel on the wind power generation, 3D modeling of our prototype of Performance of Flywheel Energy Storage on Wind Power Generation and analyzing this system through simulation.
Fabrication and thermal analysis of solar still using phase change material
(UMT Lahore, 2018-06) Muhammad Shahid.; Nouman Ahmad Mughal.; Adnan Mushtaq.
Distillation is one of the effective techniques used to purify the water. Solar still is a device which distills water using solar energy. In this study an attempt is made to investigate the effect of phase change materials on the productivity and performance of single slope solar still. A single slope wooden solar still, having base area 0.2679 m² and inclination angle of glass 30°, is used. Paraffin wax and Sodium sulphate Decca hydrate, encapsulated in circular aluminum tubes, were used as phase change materials (PCM). Experimentations were carried out by using both types of PCM and without using Phase Change material. A comprehensive comparison is made to examine the effect of phase change material on productivity and efficiency of solar still. The productivity values observed for the cases of without PCM, with paraffin wax and with sodium sulphate were 1.92 L/m² per day, 2.27 L/m² per day and 1.99 L/m² per day respectively. Results shows that the productivity of solar still is maximum for the case of paraffin wax under similar conditions. Also the maximum efficiency of solar still is observed when paraffin wax is used as energy storage medium.
Vacuum assisted resin transfer molding technology
(UMT Lahore, 2018-06) Azam Ali; Mirza Sadullah Baig; Danish Riaz
The composite materials are widely using in place of conventional materials due to its particular properties. There are a number of methods to manufacture composite material products but Vacuum Assisted Resin Transfer Molding (VARTM) technology has many advantages over RTM. It is a cost effective molding method especially using for long sheets. Our aim is to make an understanding and feasibility of this technology. Our aim is to manufacture a composite material sheet by using VARTM technology. And after that to make an understanding of VARTM for complex geometry. This is not an easy task because finishing of sheet is not easy to achieve without upper part of mold. Flow of resin effects the finishing of the part. If flow is inappropriate then voids can be produce. Flow timing is an important factor when it will slow or fast it results a defective part. Incomplete impregnation of resin will cause dry spots in the manufactured part. Distribution media places on the top of the fiber to accelerate the resin flow. So, porosity, permeability and thickness of distribution media and fiber or reinforcement are also important factors. Another challenge is to design VARTM process. Inlets for resin impregnation is an important factor that how many inlets should be for proper impregnation and where these inlets should be introduced to the mold. Leakage of vacuum bag is another challenge so proper sealing of system is required. Vacuum timing is also notable factor. Pressure and temperature of resin to introduce into the mold is also part of design challenges which we will achieve. Finishing of the final part including less voids, better surface finishing, precise and dimensions is the main aim of our project which we will achieve.
Efficiency enhancement of solar panel with automatic water cooling system
(UMT Lahore, 2018-06) Hafiz Usama Maood; Fahad Arif; Umar Qayyum
Solar energy is abundantly available clean energy which be sufficient to overcome the future energy crisis. Solar panels usage is one of the clean and easy strategy to harvest the available solar energy. The temperature of solar panel increases when they are exposed to sunlight which causes a significant decrease in its efficiency and life. In the present study an attempt is made to overcome this problem by applying cooling mechanisms. An experimental setup consisting of a solar panel integrated with water cooling system is used here. Two different shapes of ducts are considered to examine their effect on solar panel efficiency. Water is circulated in circular coil and a rectangular duct which were attached at the back of solar panel. Temperature with output power variations for the three cases, i.e. without cooling system, with rectangular duct and with circular coil, were noted for period of time. A significant increase in efficiency of solar panel is observed when cooling system is integrated with it. The average efficiency values of solar panel without cooling system with coil system and with rectangular duct system were observed as 0.8 %, 9.6 % and 17.3 % respectively. A comparison between the studied cases revealed that the efficiency of solar panel was higher when rectangular duct was used for water circulation. Moreover, application of cooling system will reduce the thermal stresses in the panel which will ultimately increase its life.
Design & fabrication of pick & place robotic arm
(UMT Lahore, 2018-06) Muhammad Dawood; Muhammad Saud; Syed Zaid Ibrahim
The aim of our project was to design and fabricate a Robotic Arm for picking and placing objects from one place to another in other words for “Pick and Place Application” which can help people in their daily use and industrial applications. Basically, the design of Robotic arm was inspired from the human arm. We used the combined knowledge of Mechanical, Electrical and computer science. Four servo motors were used in this robotic arm. Each motor served the purpose for the movements of the elbow, shoulder and gripper joints. Each servo motor took the voltage of +5V and 600mA current. Thirteen ball bearings were used for the movement of links in upward, downward, forward and backward motion and for the motion of robotic arm’s base in 180° rotation. An android mobile app “Multiple servo control” was used for the real-time programming and controlling of all the servo motors of this Robotic arm. The app was connected wirelessly through an “HC-05 Bluetooth module”. An Arduino Nano ATmega328 microcontroller was connected to the circuit which was used to program all four servo motors in the android mobile app. Four Buck converters were used for each servos whose main purpose was to convert main AC supply voltage of +12V to DC supply voltage of +12V which then helped in stepping down that +12V DC voltage to +5V DC voltage for each servo. Now-a-days, robots can cause joblessness by substituting human workers but robots also create jobs for engineers, programmers, supervisors or as a robot technician. In the age of industrial revolution the uses of this kind of technology is increasing gradually.
Design and fabriction of sub-sonic open type wind tunnel
(UMT Lahore, 2018-06) Qazi Fahad Tarik; Sanwal Bin Tahir; Usman Ali Jajja
The aerodynamic, which is the branch of the fluid dynamics, plays a very important role in our daily life. Any device that is related to aerodynamics or fluid dynamics it has to be very efficient so that it can be economical and have good efficiency. The wind tunnels are using to study the behavior of air on the machine or device related to the aerodynamics. The object with different shape like sphere, disc or any arbitrary are placed inside the tunnel with different orientation in order to study the flow patterns on it. The study of these patterns help in the reduction of the force exerting on the body in opposite direction. The aim of our project is to make an efficient design of the wind tunnel in low speed and to analyze the forces acting on the body that is placed in the test section of the wind tunnel. This tunnel will be fabricated and designed under the available data of different research papers. The objects of different shapes are placed in the section with the different placement to study the flow patterns. The gauges are used to calculate the effect of airflow on the different objects. The smoke will visualize the flow patterns to make an easy research and efficient work for the researcher or an analysis. Here, the different variables like drag force, angle of attack, lift, air velocity, surface roughness and temperature are analysis and will be varied to study behavior of the air on the object.
Designing, analysis & fabrication for prototype of highway wind turbine
(UMT Lahore, 2018-06) Ali Rehman; Ammar Aftab; Fahad Bin Qamar; Muazam Iqbal
Worldwide dependence on “GREEN ENERGY” can comprehensively be impacted by Vertical Axis Wind Turbines (VAWTs) as they possess huge prospective to contribute towards ever growing demand of green energy. For sustainable contribution of VAWTs, these turbines should be made utilizable outside their conventional farmland environments. This project features goal to utilize the power of urban environment to produce energy using VAWTs effectively and efficiently. The main purpose of this project is to design a wind turbine to utilize wind energy from atmosphere and vehicles on the highway. The turbine will be placed along medians of highways and sides of highways and effective circumstances will be considered in this report. The turbine will be designed under modern engineering standards and is given modern and effectively smart design. They also can be installed on parks, roads, public facilities or other amenities. The proposed Helix wind turbine for highways are designed to produce power up to 100 watts depending upon conditions. The power generated through turbine can be used to provide electricity to streetlights along the highways and for miscellaneous use.
Spherical solar power generator
(UMT Lahore, 2018-12) Syed Ali Raza; M. Talha Rashid; Aleem Ali Bhatti
The most ample energy source present on earth is solar energy. So if this energy utilized properly can prove to be very fruitful. Photovoltaic panels are used in order to convert solar energy into electrical energy, and these photovoltaic panels are the combination of smaller photovoltaic cells. The sunlight falling on these photovoltaic panels allow the electrons to excite and they knockout the free electrons from the atom generating flow of electricity. Our project aims to utilize this solar energy fully and to get maximum power output from the solar rays. This project includes the design of a dual axis solar tracking system on which the solar panel is mounted; the solar tracker helps to get out the maximum power output from the solar panel independent of the time. The solar tracker tracks the position of sun and always allow the solar panel to face the sun. In addition to the solar panel a spherical or circular ball made of acrylic glass is used, this sphere helps to concentrate these solar rays onto the panel so that maximum surface area of the solar panel is dealing with sunlight. The main function of this sphere made of glass is to focus the solar rays on to the panel in this way we can easily increase the efficiency of the solar panels or we can get more energy from a smaller solar panels. The technology we will be using in the project is called concentrated photovoltaic technology or (CPT).
Water purification system using solar radiation
(UMT Lahore, 2019) Muhammad Hashim Ahmad Khan; Mustafed Rehman; Sikandar Ahmad Jahangir
Water is essential need for survival of human beings. Only 1% percent of water is available for drinkable condition as Earth surface covered by 71 percent of water. So the rest of water present on Earth contaminated by some activities doing on Earth and its atmosphere. To meet with the problem of pure water. We have to purify water. Therefore, we proposed water purification using solar radiation in which we have parabolic dish containing mirror reflector and collector containing water. With the help of solar radiation, mirror reflect the solar radiation into a single point that called focal point. At that focal point, we have collector that will heat the water to vaporize form. We collect that vaporize form of water which is in purified form and we will reduce the quantity of water in collector to get more efficiency of purify water.
To investigate near wall effects of UV water disinfection reactor using CFD
(UMT, Lahore, 2019) Muhammad Yasir
Many improvements have been presented on the Ultra-violet (UV) disinfection reactor geometry in which lamp configuration, wall roughness and hydrodynamics were the main focus of the research. The turbulence of the fluid flow is significantly influenced by the presence of the wall, since it is modified by the nearness of the wall in a non-minor way. Unfortunately, no single model of turbulence is available that could deal the complexity of the fluid flow on the wall. Wall function is the pivotal to control the turbulence on the wall, different functions available which control the individual layer of the wall region. In our study we have used different wall function numerical approaches of the computational fluid dynamics (CFD) to study the effects of fluent turbulence on the reduction equivalent dose (RED) in the UV disinfection Reactor Model. For our turbulence model we used K-elipson to calculate RED under different wall functions (standard, scalable, non-equilibrium, enhanced wall treatment). Discrete ordinates radiation model was used and simulated for the UV lamp inside the reactor chamber, which has been ended up being a solid instrument for fluence rate (FR) displaying circulations in our UV reactor. Onwards critical parameter of wall functions was highlighted. We have investigated near wall effects of water disinfection and calculated the RED on each wall function with variable pathogen velocities. The simulation results provide the valuable understanding about how the RED differ or remains same between wall functions of single annular water disinfection reactor.
Design and fabrication of patient’s assistant robotic arm
(UMT Lahore, 2019-08) Faisal Arif; Umer Jalil; Wasif Sayal
The Robotic arm was designed and implemented which did a job of drinking for disabled patients or for eldery persons. Basically, the designed was inspired from the human arm. The objective of this project is to develop an automated robot using the available resources at low manufacturing cost. We use the combined knowledge of designed, programming and electrical subjects. Each link has been first designed using Creo Parametric and then fabricated by using a 3mm thick aluminum sheet. The mechanical system of the robot comprised of locomotion, gripping and lifting mechanism. Each servo motor served the purpose of the movements of the elbow and shoulders joints. The electrical system of the robot comprised of servo motors, gripper motors and some other sensors like force sensitive resistance(Measures change in pressure). Servo motor of gripper took the voltage of 5V. A single buck convertor is used for the controlling of each servo whose main purpose is to convert +12V of AC supply to +12V of DC supply. The arduino has been programmed which provides specific motion to each motor. Grippers were designed to grip a glass from a predefined position and pre-defined shape of glass. The rotation of the gripper is 1800. Gear motors are used in gripper. The links were gave a motion in upward, downward, forward and backward. Ball bearings were used in the base for their rotaion. In fabrication of the prototype robot weight was always a pivotal factor.
Energy conservation and optimization of HVAC design in-line with USGBC codes
(UMT, Lahore, 2020) ARSLAN FAISAL
With the rapid growth in global population and continuous improvement in the quality of life style, the energy consumption is at rise causing an increase in fossil combustion and ultimately pollution. Therefore, efforts are being made to optimize energy consuming systems for power utilization. In large buildings, small electrical air conditioners are not used due to their high power consumption and short running life, but preference is given to the central air conditioning for being more economical due to its lower maintenance cost and being energy efficient. Therefore, in large buildings such as auditorium, educational and commercial buildings, central air conditioning systems are used. The precise calculation of cooling load is needed to reduce capital cost and power consumption, and to maintain a comfortable environment in a building. This research work presents cooling load calculation for a building in the University of Management and Technology (UMT), Lahore, Pakistan for peak running time using cooling load temperature difference (CLTD) method. Sensible cooling load calculation for vapor compression system using CLTD method is presented to replace the existing high-power consumption cooling system, partially or completely, with an energy efficient system for maintaining human comfort without effecting indoor air quality (IAQ). The heat gains due to structure, lighting, occupancy, and equipment were simulated using Carrier's Hourly Analysis Program (HAP). The analysis of Green Building Design showed significant improvement compared with the existing building design. The analysis of a building’s HVAC design is carried out to highlight the benefits of achieving LEED standard in the UMT building.
Fixture layout and clamping force optimization for sheet metals
(UMT, Lahore, 2020) Adeel Qadir
Elastic deformation produced during machining effects the dimensional and form errors of workpiece. For precision, accuracy, fine surface finish and minimized workpiece elastic deformation; the parameters like number and position of fixture elements and clamping forces are optimized. The work on rigid bodies is well established but the work on sheet metals is still under process by various researchers due to flexible nature of the sheet metals. The objective of this research work is to optimize the number and position of the clamps and also to optimize clamping forces to keep the maximum deformation of individual nodes up to 2 mm by minimizing the total deformation normal to the plane of workpiece. N-3-2-1 fixturing principle is used to place clamps on sheet metals. The value of N≥1. Fixturing principle provides constraints on 6 Degree of freedom of workpiece and stability to workpiece which increases the machining and assembly accuracy of workpiece. In this research, design elements are the clamps of primary plane whereas locators in secondary and tertiary planes are kept non design elements. To maximize the machining area, clamps are placed only at edges of workpiece. Selection of clamps depends totally on experience of designer. Automatic selection of number and position of clamps is new. In this research, a method is proposed to select number and position of clamps for sheet metals automatically. This work consists of two stages; stage 1 and stage 2. In stage 1; optimized number and position of clamps are calculated by Response Surface Methodology (RSM). It is done by considering initial number and position of clamps from already published work. In stage 2, clamping forces are calculated for optimum layouts obtained by RSM. Stage 1 involves a structural optimization technique; Response Surface Methodology. In RSM, a relationship between set design variables; number and position of clamps and an optimal response; deformation gives an approximation model using Minitab. The second order mathematical model is developed for workpiece elastic deformation. As the predictive model is being developed by response surface methodology, a huge reduction in computational complexity and time is achieved during the optimization of number and position of clamps. The necessary data for building the response models are generally collected by the design of experiments. In this work, the collection of experimental data adopts a standard RSM design, central composite design (CCD) and the approximation of response is proposed using the fitted second-order polynomial regression model known as quadratic model. Maximum deformation for each optimized layout was kept up to 2 mm. In 2nd stage, Clamping forces are calculated for optimum layouts obtained in stage 1. To calculate the minimum clamping forces to hold the workpiece, friction forces are considered due to clamps. A method; Balancing force moment is used for calculations of clamping forces. It states; Equilibrium occurs when the sum of all forces in the x, y and z direction is zero and the sum of moments at any point is zero. Coulomb static friction law is used to verify the calculated clamping forces required to hold the workpiece. The forces in each direction are multiplied by the static friction coefficient value. It gives the friction force values due to the clamps. For equilibrium condition, the amount of friction force should be greater than or equal to the machining force in that direction. Clamping forces are calculated for optimum layouts while keeping maximum deformation up to 2 mm. Two case studies are used; flat plate and spacer grid. Different loads at different positions are applied to check the effectiveness of proposed methods. After determining the geometric center, workpiece geometry is divided in to 4 hypothetical quadrants. Quadrants with minimal deformation are considered as non-design quadrants. Quadrants with maximum deformations are considered as design quadrants. Clamps are mounted in two different ways with in the proposed method. When clamps are mounted on long edge of workpiece, the condition is called 1 design edge. When clamps are mounted on both short and long edges of the workpiece, it is called 2 design edges. Both case studies are divided into subcases. For case study 1; subcase 1, subcase 2, subcase 3, subcase 4, subcase 5, subcase 6, subcase 7 and subcase 8 are considered. For all subcases, optimized number of clamps is 4, but for subcase 1; optimized number of clamps is 5 in number. For case study 2; subcase 9, subcase 10, subcase 11 and subcase 12 are used. For all subcases optimized number of clamps is 4. Experimental setup is also designed to check the effectiveness of proposed methods. Simulation results obtained for case study 1 only are verified. The final experimental results fully justify the computational results. Maximum deformation for all subcases is less than 10%. Several factors like analogue dial indicator, human errors are the reason of difference in values.
Design and fabrication of exoskeleton arm
(UMT Lahore, 2020-07) Muhammad Kashif Sattar; Afaq Arif; Muhammad Zakria Zamir
An exoskeleton is the mechanical structures that humans can wear to increase their strength and endurance. The purpose of this study is to explain how exoskeletons can be used to improve the performance of the human body. However, exoskeletons can have the unintended negative consequences of reducing human flexibility leading to new sources of musculoskeletal disorder (MSD) and accidents. The exoskeleton arm was designed and implemented which did a great job in lifting up objects for elderly and disabled patients. This arm can also be used for lifting and exercising purposes and for therapy sessions. Basically, our design was inspired by the human arm. Our main objective of this project is to develop an exoskeleton arm by using all available resources at a low manufacturing cost. Each part of the drawing has been designed first using Creo Parametric 2.0. The 2D drawings have been created on AutoCAD. The mechanical system of the arm compromised of locomotion, lifting and gripping mechanism. A wiper motor serves the purpose of the movements of the elbow and shoulder joints. The electrical system of the robot comprised of a servo motor, potentiometer and joystick. The Arduino has been programmed which provides specific motion to a motor.

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