Robot end effector

In robotics, an end effector is the device at the end of a robotic arm, designed to interact with the environment. The exact nature of this device depends on the application of the robot.

In the strict definition, which originates from serial robotic manipulators, the end effector means the last link (or end) of the robot. At this endpoint the tools are attached. In a wider sense, an end effector can be seen as the part of a robot that interacts with the work environment. This does not refer to the wheels of a mobile robot or the feet of a humanoid robot which are also not end effectors—they are part of the robot's mobility.

Examples

The end effector of an assembly line robot would typically be a welding head, or a paint spray gun. A surgical robot's end effector could be a scalpel or others tools used in surgery. Other possible end effectors are machine tools, like a drill or milling cutters. The end effector on the space shuttle’s robotic arm uses a pattern of wires which close like the aperture of a camera around a handle or other grasping point.

When referring to robotic prehension there are four general categories of robot grippers, these are^[1]:

1. Impactive – jaws or claws which physically grasp by direct impact upon the object.
2. Ingressive – pins, needles or hackles which physically penetrate the surface of the object (used in textile, carbon and glass fibre handling).
3. Astrictive – suction forces applied to the objects surface (whether by vacuum, magneto– or electroadhesion).
4. Contigutive – requiring direct contact for adhesion to take place (such as glue, surface tension or freezing).

Examples of end effectors

•  
  An example of a basic gripping end effector
•  
  A spot welding end effector
• A laser welding end effector
•  
  A repair and observation end effector in use in space (Canadarm)
•  
  A highly sophisticated attempt at reproducing the human end effector

See also

• Grapple (tool)
• Tongs
• Shadow Hand

References

1. Monkman, G. J.; Hesse, S.; Steinmann, R.; Schunk, H. (2007). Robot Grippers. Wiley-VCH. p. 62. ISBN 978-3-527-40619-7.

• Koren, Y. (1985). Robotics for engineers. McGraw-Hill. ISBN 0-07-035399-9
• Monkman. G.J., Hesse. S., Steinmann. R. & Schunk. H. Robot Grippers. Wiley. ISBN 978-3-527-40619-7