Thursday, 29 August 2013

inline and ezplot functions elaborated

You can simply plot the function by using inline and ezplot command in the following way:





> fcn = inline('exp(-0.2*t).*sin(200*t+pi/20)','t')

fcn =

     Inline function:
     fcn(t) = exp(-0.2*t).*sin(200*t+pi/20)

>> fcn(0:10e-4:0.4);

>> ezplot(fcn)

time t array can be varied and again a new c=plot can be achieved

Wednesday, 28 August 2013

Matlab code for switch case function: Conversion of units of length

% Matlab program to demonstrate switch case function

x = 3.0;               % numeric variable for length
units = 'cm';         % string variable for unit
switch     units
    case    {'in','inch'}      % case 1 if unit is inch
           y = 2.54*x;        % converts to centimeters
          disp  ([num2str(x)  '   ' units ' converted to cm is :' num2str(y)])
            %  disp is used to print pretty in the command window
            %  in the above a string vector is being printed
     case   {'m','meter'}    % case 2 unit is meter
           y = x*100;        % converts to centimeters
           disp  ([num2str(x)  '   ' units ' converted to cm is :' num2str(y)])
     case   { 'millimeter','mm'} % case 3 unit is millimeter
           y = x/10;
          disp  ([num2str(x)  '   ' units ' converted to cm is :' num2str(y)])
    case {'cm','centimeter'}     % case 4 unit is centimeter
          y = x;
          disp  ([num2str(x)  '   ' units ' converted to cm is :' num2str(y)])
    otherwise                    % for all other cases
         disp    (['unknown units:' units])
         y = nan;  % not a number
end

Sunday, 18 August 2013

Prosthetic hands for manipulating objects for disabled

In this project, students learn how prostheses that use robotic technology can improve the lives of people with disabilities. In the laboratory, the students can use Lego Mindstorms NXT kits to create an artificial arm or hand that can lift small objects, such as a coffee cup. In the process, students discover and explore the following concepts and ideas: Hooke's Law, hysteresis, Newton's Second Law, accuracy and precision, rapid prototyping, and the relationship between the voltage applied to a motor and its speed.

Ant Colony Optimization (ACO) for engineering research and projects

Ant colonies, and more generally social insect societies, are distributed systems that, in spite of the simplicity of their individuals, present a highly structured social organization. As a result of this organization, ant colonies can accomplish complex tasks that in some cases far exceed the individual capabilities of a single ant. The field of ‘‘ant algorithms’’ studies models derived from the observation of real ants’ behavior, and uses these models as a source of inspiration for the design of novel algorithms for the solution of optimization and distributed control problems. The main idea is that the self-organizing principles which allow the highly coordinated behavior of real ants can be exploited to coordinate populations of artificial agents that collaborate to solve computational problems. Several different aspects of the behavior of ant colonies have inspired different kinds of ant algorithms. Examples are foraging, division of labor, brood sorting, and cooperative transport. In all these examples, ants coordinate their activities via stigmergy, a form of indirect communication mediated by modifications of the environment. For example, a foraging ant deposits a chemical on the ground which increases the probability that other ants will follow the same path. Biologists have shown that many colony-level behaviors observed in social insects can be explained via rather simple models in which only stigmergic communication is present. In other words, biologists have shown that it is often su‰cient to consider stigmergic, indirect communication to explain how social insects can achieve self-organization. The idea behind ant algorithms is then to use a form of artificial stigmergy to coordinate societies of artificial agents.


This technique of ant communication for finding the shortest available path between their nest and the food source by depositing pheromones can be applied for optimization various engineering problems and there comparison with other conventional techniques. 

Induction motor drive by 3-level PWM inverter by v/f method

Be it domestic application or industry, motion control is required everywhere. The systems that are employed for this purpose are called drives. Such a system, if makes use of electric motors is known as an electrical drive. In electrical drives, use of various sensors and control algorithms is done to control the speed of the motor using suitable speed control methods. Earlier only dc motors were employed for drives requiring variable speeds due to ease of their speed control methods. The conventional methods of speed control of an induction motor were either too expensive or too inefficient thus restricting their application to only constant speed drives. However, modern trends and development of speed control methods of an induction motor have increased the use of induction motors in electrical drives extensively. In this project, we will study the various methods of speed control of a 3-ph induction motor and compared them using their Torque-Speed characteristics. Also the transients during the starting of a 3-ph induction motor will be studied using MATLAB Simulink and the effects of various parameters such as rotor and stator resistances and inductances well be analyzed

Project: Matlab/Simulink modeling of PV cell and their comparative study

Solar energy has a major role in renewable energy resources. Solar Cell as a basement of solar system has attracted lots of research. To conduct a study about solar energy system, an authenticated model is required. Diode base PV models are widely used by researchers. These models are classified based on the number of diodes used in them. Single and two-diode models are well studied. Single-diode models may have two, three or four elements. In this project, these solar cell models are examined and the simulation results are compared to each other. All PV models are re-designed in the Matlab/Simulink software and they examined by certain test conditions and parameters. This project will provide comparative studies of these models and it tries to compare the simulation results with manufacturer’s data sheet to investigate model validity and accuracy.