27-07-2012, 01:49 PM
METAL OBJECT FOLLOWER ROBOT USING VISION SYSTEM
METAL OBJECT FOLLOWER ROBOT.docx (Size: 87.29 KB / Downloads: 47)
Introduction
Visual servoing, also known as Vision-Based Robot Control and abbreviated VS, is a technique which uses feedback information extracted from a vision sensor to control the motion of a robot. Visual servoing canbe useful for a wide range of applications and it can be used to control many different dynamic systems (manipulator arms, mobile robots, aircraft, etc.). Visual servoing systems are generally classified depending on the number of cameras, on the position of the camera with respect to the robot, on the design of the error function to minimize in order to reposition the robot.
Description
Vision feedback control loops have been introduced in order to increase the flexibility and the accuracy of robotic systems. The aim of the visual servoing approach is to control a robot using the information provided by a vision system. Here the vision system is camera (Logitech pro 9000).
Mat lab simulations are generally used to get assistance in understanding an overall picture of the problem and to find a decent solution to the problem. It is clear that Robot is a non-linear system. Therefore, checking a stability of the robot is little bit complicated. Hence, a simple code in m-file was written.
Ultrasonic sensors measurement:
The ultrasonic distance sensor provides precise, non-contact distance measurements. It transmits an ultrasonic burst to detect any obstacle and outputs a pulse. The output pulse width corresponds to the time required for the burst echo to return to the sensor. The distance between the robot and a wall can be determined by multiplying the pulse width and the velocity of the ultrasonic burst. The ultrasonic sensor (PING) by Parallax Inc. has a male three-pin header used for+5V supply (Vdd), ground (Vss), and signal as shown in Figure 4. Since there is only one pin for signal, the input pulse transmitted and the output pulse received at the same pin.
Methodology
Different image processingtechniques are adopted and combined to achieve optimal results. The robot has been programmed to perform tracking once target is detected, or to continue the search otherwise.
Conclusion
The aim of the document is to design a robot which detects the metal objects using ultrasonic sensors and move along the object detected direction.