A Study in Industrial Robot Programming

|
All materials on our website are shared by users. If you have any questions about copyright issues, please report us to resolve them. We are always happy to assist you.
 10 views
of 26

Please download to get full document.

View again

Description
A STUDY IN INDUSTRIAL ROBOT PROGRAMMING YUSMARNITA BINTI YUSOP A thesis submitted in partial fulfillment of the requirements for the award of the Degree of Master of Engineering (Electrical) Kolej Universiti Teknologi Tun HusseShhn NOVEMBER 2004 ABSTRACT This project is concerned with learning the technology and programming of servo controlled industrial robots. A Mitsubishi RV-2AJ articulated robot was used in this project. The project work is divided into two parts: In the first part o
Share
Tags
Transcript
  A STUDY IN INDUSTRIAL ROBOT PROGRAMMINGYUSMARNITA BINTI YUSOP A thesis submitted in partial fulfillment of the requirements for the award of theDegree of Master of Engineering (Electrical)Kolej Universiti Teknologi Tun HusseShhn NOVEMBER 2004  ABSTRACT This project is concerned with learning the technology and programming ofservo controlled industrial robots. A Mitsubishi RV-2AJ articulated robot was used inthis project. The project work is divided into two parts: In the first part of the projectthe author familiarized herself with the operation and programming of the robot'smanipulator and controller hardware by carrying out some laboratory experiments. A set of laboratory sheets were produced from this exercise. In the second part, theauthor studied the mechanics of software control of the robot. A user-defined trajectory planning routine based on the cubic spline fitting function has successfullybeen developed in this project.  CHAPTER 1INTRODUCTION 1.1 Overview Multi-axis machines are used in a variety of applications: pick-and-placeoperations, welding, machining, etc. Such machines can be divided into two units: thephysical mechanism composed of links and actuators, and the control system. Thenumber of actuators present in the mechanical system depends on the number ofindependent machine axes, or degrees of freedom. For example, a typical articulatedsix degree of freedom manipulator contains six rotating actuators. A five-axis high-speed CNC machining centre would contain three linear actuators and two rotatingactuators. A motion task given to the machine must ultimately be represented as areference signal, which is sent to the control system. The control system acts to makethe machine track the reference signal by activating the appropriate actuators. If thereference signal changes too quickly, given the dynamic limitations of the machine,the traclung of the reference signal will be poor, regardless of the control system  design. Computer algorithms are designed to calculate an appropriate reference signalbased on the desired task path and time-related limits (such as speed and acceleration).This reference signal is the trajectory, and can be defied as a locus of points inoperational or joint space on which a time-law has been specified [I]. The generationof an appropriate trajectory is the problem that is being investigated in this thesis.The path along which the trajectory is defined can be point-to-point; namely,the machine is required to move between the two points but is not given any fixedintermediate path. This type of path is useful in manipulator pick-and-placeoperations. A path can also be completely specified through use of geometricfunctions. This type of path is commonly used in CNC machining applications or inmanipulator applications when obstacles are present, or when it is necessary to ensurethat the end effector follows a specific path. Herein it is assumed that the pathdefinition is provided, and the problem of path planning is not specifically addressed.The control of the machine motion can be divided into two parts: motionplanning and motion tracking. Motion planning involves generating the path and itstime law, providing the controller's reference signal. Motion tracking, on the otherhand, is concerned with improving the tracking of the reference signal. Motionplanning is often done off-line, typically when the trajectory generation algorithms arecomputationally intensive. However, it is often desirable to generate trajectories on-line so that changes can easily be made to the machine's trajectory, increasing thesystem's overall robustness and adaptability. For example, a manipulator may requirethe ability to recompute its trajectory on-line in order to avoid an unexpected obstaclethat lies along a path on which it is currently moving 121. In an automated robotworkcell, a high level scheduler feeds a series of tasks to a manipulator in terms ofwaypoints, approach points and stop points. The manipulator must execute the task bygenerating paths and trajectories to these points and then following these trajectoriesusing a control law. Use of an on-line planner reduces manipulator setup time anddowntime, since the time required to plan the trajectories is shorter.
Related Search
We Need Your Support
Thank you for visiting our website and your interest in our free products and services. We are nonprofit website to share and download documents. To the running of this website, we need your help to support us.

Thanks to everyone for your continued support.

No, Thanks