Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. PowerPoint to accompany Krar Gill Smid Technology of Machine Tools 6 th Edition Robotics Unit 96

96-2 Objectives Describe industrial robots and provide applications of their use Identify the different types of robots, describe their basic principle, and list their main parts Understand vision-based robotics State the four modes of programming robots List the advantages of robots Recognize the safety precautions required when working with robots

96-3 Industrial Robot Defined as programmable, multi-functional manipulator designed to move parts, and tools through programmed motions First American application was in automotive industry in early 1960s Used in all types of manufacturing/assembly Were prime factors of growth of industrial production in 1980s and 1990s

96-4 Robot Requirements Can be adaptable for many applications Reliable Easy to program Safe to operate Capable of working in hazardous places

96-5 Application Flexibility Handling –Load, unload, retrieving parts, forging Processing –Metalizing, seam welding, spot welding, cleaning Assembly –Riveting, drilling, reaming, insertion and tightening Sealing and painting –Applying grease/adhesives, spray painting

96-6 Robots Equipped with set of grippers (end-effectors) –Located at end of single arm and used to perform an operation or pick and move item Able to reach all locations in work area with speed and fluid motion Very accurate in following programmed path Key requirements –Versatility, high repeatability, compactness and ease of programming

96-7 Three Parts of a Robot Arm –For using tools and moving parts –Also called manipulator Can move in 6 or more axes including rotary motion Power Supply –Electrically powered for low power consumption, smooth motion and reliability Computer –Controls actions

96-8 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

96-9 Types of Sensors Tactile (touch) sensors –Located in gripper to feel or fit parts Vision system –Identifies type and rotational position of object –Help control direction of gripping pressure Force or torque sensors –Indicate resistance force of object and adjust gripping pressure

96-10 Vision-Based Robotics Used to automate high-speed assembly Improvements in robotic photoelectric diodes Black and white video cameras used System of template matching used and process by computer analysis

96-11 Intelligent Vision for Robots Next generation of manufacturing systems Will improve robots present senses –Allow them greater flexibility –Will perform more complex tasks more quickly Researchers trying to duplicate human eye movements –Try to duplicate how human vision system processes information and makes predictions Use smart cameras to mimic human vision

96-12 Artificial Intelligence Speed of robot tied to control languages and software stored in computer program Four ways of programming robots –Manual mode –Teach mode –Automatic mode –Off-line programming

96-13 Manual Mode Robot taught by leading arm through necessary movements by operator Movements stored in memory to be used again Suited for operations difficult to explain or program

96-14 Teach Mode Axes of robot arm moved by use of portable teach pendant Movement within coordinate system controlled by pendant's pushbuttons Human operator teaches how to perform specific tasks within coordinate system

96-15 Automatic Mode Movement controlled by computer program Types of control languages –VAL (Versatile Assembly Language) most common –KAREL Named after person who introduced term robot –Cover range of motion, grippers, input/output

96-16 Off-line Programming Programming robot and simulating movements on computer screen Provides check on accuracy of programming Provides opportunity to change programming and avoid costly crashes

96-17 Next-Generation Manufacturing Incorporates open communications, flexible adaptive intelligent behavior Benefit spanning productivity, cost and human safety Vision systems will allow more complex tasks to be accomplished

96-18 Factors Used to Justify Cost of Robotics Vision Systems 100% inspection Statistical Process Control required Number of parts produced per month Number of production operators/lines/shifts Manual Inspection time per piece Number of rejects per month Monthly warranty/liability costs, scrap/waste inventory costs and monthly units sales

96-19 Advantages of Robots Computer controls position, orientation, velocity and acceleration of path of tool center point at all times Can be easily taught with the teach pendant Computer can store system software and taught data in memory Program in computer's memory easily expanded with extra functions

96-20 Advantages of Robots Can be interfaced with other equipment, provide valuable data to supervisory computer and receive and interpret signals System can be easily changed Computer able to monitor robot and equipment in service

96-21 Safety Precautions Enclose working area to prevent people from entering Make emergency stop buttons available outside working range Programmed, serviced and operated only by fully trained workers

96-22 Safety Precautions Use extreme care during programming cycle Work done should not be a health or safety hazard to human workers nearby Place Hydraulic and electrical cables so cannot be damaged during operation