Browsing by Author "Bunchan, Rewat"

Filter results by typing the first few letters
Now showing 1 - 2 of 2
  • No Thumbnail Available
    Item
    A binary hyper redundant elephant trunk like robot controlled by microcontroller and plc-wincc
    (Department of Mechanical Engineering, BUET, 2011-12-18) Hasan, Mahadi; Bunchan, Rewat; I. E. L, Bohez; Islam, Md. Ashraful; Wakil, Abdul
    The word hyper-redundant refers to the robot manipulators that have a large or infinite degrees of kinematic redundancy. These robots resemble in shape and operation to snakes, elephant trunks, or tentacles and thus termed bio-inspired. Binary actuation, here in this study pneumatic cylinder, was the mechanical analogy to digital electronics, where actuators flip between two discrete states on and off. For applications where high repeatability, low cost, no necessity for feedback control and reasonable accuracy are required, hyper-redundant binary manipulators based on parallel platform are potential candidates. Here, in this study two different algorithms have been applied to control the robot, a 5-module binary robot built with the aim of demonstrating the potentials of hyper-redundant binary manipulator based on parallel mechanism. The Microcontroller, based on Genetic Algorithm (GA for solving inverse kinematics problem of the binary mechanism) along with a connecting board to the solenoid valves, was found to be a successful controller of the Elephant Trunk like Robot with some ineluctable drawbacks analyzed in detail. Afterword PLC controller was implemented where WINCC acted as the Human Machine Interface (HMI) and considered as a primary solver of the limitations appeared by the Microcontroller with remaining few constraints itself too. A 3-D model of the robot has been drawn in Solid Work and analyzed the motion of the robot with the help of COSMOS Motion Analysis in Solid Work 2010. The program for controlling 30 solenoid valves of 5 module robot (each module 6 cylinders) with 30 inputs and 30 outputs was written in PLC. Visual graphics for both manual and automatic mode control were drawn in WINCC. And finally a substantial comparison between two controllers was made
  • No Thumbnail Available
    Item
    PD controller for balancing an inverted pendulumn cart
    (Dhaka University, 2011-12-18) Hasan, Mahadi; Bunchan, Rewat; Islam, Md. Ashraful; Sivapornsatian, Jakkit; Wakil, Abdul
    In the arena of Control theory and Engineering, balancing of an inverted pendulum by moving a carrier (cart) along a horizontal track, is a classical problem for the commencers to analyze its dynamics as it continually moves toward an unstable state. Numerous physical models resembling to the same include Flight Simulation of rocket or missile during the initial stages of flight, Simulation of dynamics of a robotic arm, Model of a human standing still etc. Many researches concentrating on this field have been using different control algorithms and design techniques from PID controller, state space, neural network, genetic algorithm (GA) to particle swam optimization (PSO), in both digital and analog domain using various sensors. However, this can also be performed using a single potentiometer as a sensor and PD controller as the design algorithm. The difference between the reference (zero voltage) and potentiometer (voltage difference due to change in resistance) generates control signal to drive the system. Here, in this work, it consists of a thin vertical rod attached at the bottom (pivot point), mounted on a mobile toy car. The car, depending upon the direction of the deflection of the pendulum moves horizontally in order to bring the pendulum to absolute rest. The main idea behind this control process was the use of PD (Proportional and Derivative) controller to generate signal to control the speed and direction of the motor. The only sensor used in this project was a potentiometer. It was attached to the pendulum rod and the variation in its resistance caused change in voltage across it which was compared with the reference voltage (zero) to generate the appropriate control signal. PROTIUS software was used for circuit simulation, frequency responses of the system were analyzed in MATLAB with different values of gains, KP and KD, and finally the Root Locus diagram showing the system stability was drawn in MATLAB.