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Simply put, an end-effector is the tool mounted to the end of the robot that does the work.  There are many different applications of industrial robots and they all have specific end-effectors used to accomplish the task.

TOPIC 1: Welding

These two videos show a robots spot welding.  Spot welding is the most common application of welding robots.  This process is completed by mounting a spot welder to the robot and using the robot to position the welder at each weld point.

While the arc has been turned off, this is a good example of arc welding robots.  (No need to watch this video past 1:17).  This is the same concept except that the the robot is now using an arc welder.  Just as human controlled welding, surface velocity is of greatest concern to insure a good and even bead.

TOPIC 2: Assembly

Robots are also commonly used to put things together.  In this case, a robot will likely have a pneumatic gripper or a vaccuum cup to move parts through the process.  Here is an example of this activity with a motoman robot.  While it looks human, it is nothing more than two robots mounted sideways on a rotating platform with coordinated motion.

TOPIC 3: Coating

Robots that paint or spray adhesives are common in many industries.  One of the greatest concerns with painting robots is the risk of spark because a spark could cause an explosion.  Robots that are designed to spray paint have special equipment to insure that no sparks will be generated.  They are also often equipped with a coat to prevent paint from collecting on the surface of the arm.  This coat is a consumable and can be changed relatively easily.  This may be a part of a maintenance procedure for the robot.  Robots are normally sized based on their capacity to carry a payload and their reach.  For a painting robot the payload is of little concern as the end-effector is a small spray gun.  However, the reach of the robot is critical in this application as the robot must be able to reach great distances.  As can be seen in the second video, it is sometimes not feasible to reach the entire part so either the robot is mounted to a linear track or the part is moved in front of the robot.

TOPIC 4: Dispensing

Dispensing is another common application where robots are given what amounts to a hot glue gun.  As you can imagine there a several critical aspects.  Surface velocity must be maitained and angle of application must be taken into consideration.  For example the dispensed material may flow better if dispensed from above onto a surface instead of try to dispense up onto a surface.  Here is a video that shows may different robots dispensing glue or foam.

TOPIC 5: Inspection

Inspection robots use lasers, vision systems, or another type of measurement tool as an end-effector.  Effectively this application is similar to an inline CMM machine that can take measurement data on each product to insure compliance.  The robot velocities or paths are not critical as these robots are merely positioning the end-effector and allowing them to do their job.  The robot does not typically move while the measurement system is functioning.

TOPIC 6: Material Handling

Material handling robots range from palletizers to machine loading and unloading

TOPIC 7: Material Removal

Robots tasked with material removal exist in two forms, robots designed to pick up the part and present it to a cutter and robots designed to wield a cutter or other material removal device.  In the first example below, the robot is making decisions based on a vision system to cut bacon from pork pieces.  In the second video the robot presents an aluminum casting to a sander.

TOPIC 8: Other strange applications

Robots can virtually be outfitted with anything that does not exceed the payload limitation of the robot.  Strange examples include a chair with seatbelt in a “roller coaster” ride in a mall, used in a movie, or they can be used to serve ice cream!

You should now be prepared to answer the following questions.

1. An end-effecter is ________.
2. True or False?  When several robots are welding on the same piece of metal only one can weld at a time due to the flow of electricity.
3. True or False?  A robot can only control one welder at a time.
4. The largest concern with a painting robot is _____.
5. How many robots are used to paint the wind turbine blade in the example?
6. True or False?  Surface velocity is important when using dispensing robots.
7. True or False?  Inspection robots are designed to position a measuring device and typically do not move while the inspection device is functioning.
8. True or False?  Material removal robots always take the work piece to the tooling because it is not safe for the robot to wield a tool used in material removal.
9. In the video of the robot cutting pork, the robot is seen cutting _____ pieces
10. The robocoaster shown in TOPIC 8 holds _____ people at once.