Industrial Robotics Chap 01 FundamentalsPresentation Transcript
Introduction to Robotics Prof A S Rao Robotics & CAD/CAM Laboratory Mechanical Engineering Department VEERMATA JIJABAI TECHNOLOGICAL INSTITUTE MUMBAI-400019
What is Robotics
Laws of Robotics
Robot Reference Frames
What is a Robot
What is Robotics:
Robotics is an interdisciplinary subject that benefits from mechanical engineering, electrical and electronic engineering, computer science, biology and many other disciplines.
Robotics is defined as that branch of engineering which deals with the study of different types of robots, their simulations, their designs, their constructions, operations, performance etc.
Robotics is a form of Industrial Automation and is a technology with a future and a technology for the future
What is a Robot :
When we compare a crane attached to a utility or towing vehicle and robot manipulator which appears to be very similar because :
Both posses a number of links attached serially to each other with joints
In both the systems, the hand of the manipulator can be moved in space and be placed in any desired location with in the workspace of the system
Each one is controlled by a central controller which controls the actuators
However one is called a robot and the other a manipulator (i.e. a crane)
The fundamental difference between the two is that the crane is controlled by a human who operates and controls the actuators, whereas a robot manipulator is controlled by a computer that runs a program.
What is a Robot : Definition :
The Automatic progrmmable machines which does the required job through various programmed motions
According to RIA: A robot is a reprogrammable multifunctional manipulator designed to move various objects, tools, materials or specialized devices through variable programmed motions for the performance of variety of tasks
Law of Japan states that a robot is “All purpose machine equipped with a memory device (for handling) capable of replacing human labour for the automatic performance of tasks”
Robert Schilling defines a robot as “a software controlled mechanical device that uses sensors to guide one or more of its end effectors through various programmed motions in a work space in order to manipulate physical objects”
Classification of Robots:
Work Envelope/Coordinate Geometry
Motion Control Methods
I. Drive Technology:
Motors are part of any robot system they produce spatial displacement and control axis motions of the robot. Based on power used to drive the joints of the robot the 3 drive technologies are :
Electrical drive technology
Hydraulic drive technology
Pneumatic drive technology
1. Electrical drive technology:
Most Robotic manipulators today use electric drives in the form of either D.C.Servomotors or D.C.Stepped motors
D.C.Servomotors : More controllability for precision work (neat/precise)
D.C.Stepped motors : Load carrying capacity is large
IC manufacture, etc
2. Hydraulic drive technology:
Robotic manipulator which uses oil/liquid/gel as a drive technology. We use it for very heavy load carrying capacity purpose.
Limitation : Cleanliness will not be maintained
In steel industry for carrying molten steel
3. Pneumatic drive technology: It is used as at the gripper for manipulating delicate objects, e.g. used in glass industry. The robot operates from compressed air and they are activated tools. Limitation: Built in compliance of air, i.e. air can be compressed, creates noise while operation. Application: Used in pick and place operations in glass industry
II. Work Envelope/Coordinate Geometry : Work Envelope is defined as locus of points in 3 Dimensional space that can be reached by the wrist of robot. It consists of Rotary/Revolute motion about an axis and Translation motion along an axis (i.e. linear/sliding/prismatic/translate)
III. Motion Control Methods :
Point to Point motion : The discrete points are specified, the tool moves in a sequence of discrete points in the workspace.
Continuous or Controlled path motion : The end effector must follow a prescribed path in 3D space and speed of motion along the path may vary
Examples : PTP : Spot welding, Loading & Unloading, Pick and Place, etc.