Industrial Robots INDUSTRIAL ROBOTS IN THE AUTOMATED MANUFACTURING INDUSTRY CAM 6132

Industrial Robots JUSTIFICATION & ROBOT AXES CAM 6132

Justification  Benefits: 1. Cuts cost for the company 2. Accuracy & Precision 3. Durability 4. Material saving and scrap reduction 5. Quick & efficient CAM 6132

1. Cuts cost for company  Robots can complete multiple tasks a human can do. With a robot the tasks will be done at a cheaper cost than hiring a employee.  Companies are responsible for the follow when an employee is hired  Salary  Sick leave  Insurance  Robot arms are generally $50-75 thousand used and $ thousand new at once compared to a line worker who can make up to $25/hr which can equate to $52,00/year in salary alone, sick leaves and insurance will add more to that cost. Over a long period of time this employee has been a rather costly investments. CAM 6132

2. Accuracy and precision  Precise maneuvering due to computer programming  Accuracy to fractions of an inch  Virtually no mistakes made from the robot itself CAM 6132

3. Durability  Robots are manufactured tough for repeatability thus resulting in long term durability  Small components of most robots can be replaced for a fraction of the cost  On average companies expect around 8 years for an industrial arm to last, however many companies have had their arms for almost 20 years. CAM 6132

4. Material saving and scrap reduction  Less scraps and waste due to accuracy and precision  Can use smaller stock for machining CAM 6132

5. Quick & efficient  Complete virtually any task a human can do in a faster time  Work efficiently without distraction, setbacks etc. CAM 6132

Robot Axes 1. Sweep 2. Swivel 3. Extension 4. Pitch 5. Roll 6. Yaw CAM 6132

1. Sweep  Sweep movement of a robot arm allows the arm to rotate from left to right.  This gives the robot full degree of freedom from the center point. CAM 6132

2. Swivel  The swivel axis allows the lower arm to move forward and backwards CAM 6132

3. Extension  The extension axis accounts for the arms vertical reach  Allows the upper arm to raise and lower CAM 6132

4. Pitch  Pitch is the arms “wrist” motion up and down CAM 6132

5. Roll  Roll rotates the arms “wrist CAM 6132

6. Yaw  Yaw moves the arms “wrist” left and right CAM 6132

Video Demonstration  CAM 6132

Industrial Robots CONFIGURATIONS AND WORK ENVELOPE CAM 6132

Manufacturing Applications  There are many applications for robotics in automated manufacturing:  Welding  Arc and Spot Welding  Spray Painting  Materials handling  Transport, Pick and Place, Palletizing  Machining processes  The most utilized among robotics is pick and place operations CAM 6132

Pick and Place  A fundamental operation that is used among robotics in the automated manufacturing industry  As the name states, the part is picked up and placed to appropriate locations for future operations  Requirements of pick and place:  The object cannot be dropped  Part must be held firmly yet not damage it  Object cannot be disturbed upon approach and departure of robot CAM 6132

Pick and Place  Examples of pick and place operations:  Pallet loading/unloading  Die-casting of metals (locking and unloading material/parts)  Loading and unloading of parts into manufacturing machines CAM 6132

Pick and Place  A pick and place robot can essentially replace a human job by programming the tedious, repetitive process  Pick and Place robots can operate 24 hours a day, problem- free  The locational accuracy that these robots can achieve are superior and more importantly, repeatable for an endless cycle CAM 6132

Servo Controlled Robotics  Also called continuous path robots  Contain internal sensors that record and control velocity, acceleration, and location from the start of the path to the end  Due to the precise operation, these robots can operate swiftly and with unmatched accuracy CAM 6132

Servo Controlled Robots  Most common industrial robot utilized in the industry  Movements can change mid-path without activating/deactivating a mechanical switch  Multiple directional movements are common, 5 to 7 movements (limited by the robot’s mechanical ability) CAM 6132

Importance of Servo Controlled Robots  Due to the accuracy required for automated manufacturing, servo controlled robots are very important for part quality  Also, the operating speed allows fast processing/manufacturing  Allows the manufacture to produce more parts with higher quality CAM 6132

Movements Cylindrical - Rotating about Z-axis - Essential for rotating position and removal of parts Cartesian - Translations on the X and Y axis Polar - Spherical movements about the center point of the robot pivot CAM 6132

Work Envelope  Important to understand and utilize the work envelope to the operator’s advantage  The work envelope is the area which the robot can move  The more flexible the robot is, the larger the work envelope is CAM 6132

Work Envelope  Areas of which the robot cannot access or reach are called dead zones  Depending on the mechanical design of the robot, it may be restricted to certain areas of the working envelope CAM 6132

Work Envelope  The work envelope does not include the end effector (Tool or equipment at the end of the robot that performs specifically performs the desired operation  The end effector increases the work envelope of the robot, usually stated in the tool manufacture  Extra care must be taken to recognize the increased work CAM 6132

Tooling CAM 6132

Types of Tooling  Grippers  Mechanical Grippers  Suction cups or vacuum cups  Magnetized grippers  Hooks  Scoops (to carry Fluids)  Spot Welding gun  Arc welding tools  Spray Painting gun  Drilling Spindle  Grinders, Wire Brushes  Heating torches CAM 6132

Tooling  In robotics the components at the end of robot arms are referred to as “End Effectors”  End Effectors are used to interact with the environment around them to complete their designated task  End Effectors are broken up into groups, some designed for specialized task were other are for general use CAM 6132

Grippers CAM 6132

Mechanical Grippers  Mechanicals Grippers are claws made of linkages actuated by pivoting, linear or translation movements  The linkages take the motion and convert it into a gripping force used to grasp objects  Simple yet effective method for grabbing flat surfaces  Pneumatics can be used to actuate linkages, effective for smaller grippers and low production cost  Mechanical grippers rely on friction between the gripper and the work piece, pads are often used to increase this amount of friction CAM 6132

Suction/Vacuum Cup Grippers  Utilizes air pressure and vacuum pressure to grip an object for transport  Vacuum grippers require a seal to be formed on the surface of object to create strong grip strength  Useful for transporting sensitive or fragile objects as no marks are left on work part  Suction tip can be large or small depending on the required task and size of object being moved  Multiple suction heads can be used to grasp large numbers of object simultaneously or selectively CAM 6132

Great for high production runs CAM 6132

CAM 6132

Magnetizing Grippers  Electromagnet used at end of arm to grab ferrous metal objects  DC power passes through the magnet creating an intense electric field (DC power is used for it stability and one direction flow)  Strong grip strength, effective for transposing heavy objects  When a permanent magnet is used, a push off pin is needed to separate the piece from the magnet  Magnetic grippers have a fast gripping speed with only one surface needed  Does not require a seal to grip CAM 6132

Hooks and Scoops  Hooks and scoops are some of the simplest forms of grippers  A Scoop or ladle is often used to scoop and transport molten metal to castings  Sometimes a hook is all that is need to transfer an object or work piece, especially if high precision is not required  Hooks are good end effectors when the work piece is to be dipped in liquid CAM 6132

Arc Welding  A welding tip is added to an end effecter in place of a gripper  This method is most effective if the seam to be welded does not deviate from a straight path by less then half the diameter of the welding wire  A sensor is added to the robot arm to detect the seam to be welded  3 methods for sensing are  TAST (Through-arc seam welding)  Laser-based systems  Though sensing  Tandem arc welding can produce welds up to 200 inches per minute CAM 6132

Spot Welder  Spot welding arms close together with work piece in the center  With pre-determined pattern, welds can be produced quickly  Access to part is limited to by length of spot welding arms  Low clamping force is needed because only contact is needed to create an arc  Sensors on welding tips are much more difficult to achieve CAM 6132

Spray Painting Gun  Painting arms can produce consistent and reproducible results  Paint is fed through lines in the robot arm as well as compressed air  Compressed air is forced out the paint nozzle creating a mist spray  A dressing is required to cover the robot components to prevent components from being effected by the mist  Other liquids like sealants and primers can be dispensed by the nozzle as well CAM 6132

Drilling Spindle  The Drill Spindle is the equivalent putting a mill on the end of a robot arm  Drill spindles are capable of creating holes with extreme precision as well as carving from a solid block of material  Drilling and Milling tools can be placed in the chuck  Multiple holes can be drilled simultaneously  Drilling on angles can be done to a large degree of freedom CAM 6132

Grinders, Wire brushes  A grinding or polishing disk is placed onto a spindle  Capable of producing chamfered edges with a high degree of accuracy  Only effective in certain applications, access to small spaces is difficult  Safety guards are still used as humans are still present to replace grinding disks and cycle work components if necessary  Capable of producing consistent results as well as good finish CAM 6132

Heating Torches  Commonly used in conjunction with welding attachments  Heating Torches also are used to cut metal producing accurate and straight cuts with high precision  Heating torches may be used to apply heat for thermal expansion of desired components to be mated together CAM 6132

References  Industrial Automation and Robotics  By A. K. Gupta, S. K. Arora  Smart Robots: A Handbook of Intelligent Robotic Systems  By V. Hunt  Robotics  By Appuu Kuttan CAM 6132

References  Industrial Robotics: selection, design, and maintenance  By Colestock, H. (2005)  Industrial Robotics: How to implement the right system for your plant  By Glaser, A (2009) CAM 6132

References  Intelligent Robotics and Applications  H. Liu, N. Kubota, X. Zhu, R. Dillmann, D. Zhou CAM 6132