
The SCARA is a type of
industrial robot. The acronym stands for Selective Compliance Assembly Robot Arm or Selective Compliance Articulated Robot Arm.
By virtue of the SCARA's parallel-axis joint layout, the arm is slightly
compliant in the X-Y direction but rigid in the Z direction, hence the term ''selective compliance''. This is advantageous for many types of assembly operations, for example, inserting a round pin in a round hole without binding.
The second attribute of the SCARA is the jointed two-link arm layout similar to
human arms, hence the often-used term, ''articulated''. This feature allows the arm to extend into confined areas and then retract or "fold up" out of the way. This is advantageous for transferring parts from one cell to another or for loading or unloading process stations that are enclosed.
SCARAs are generally faster than comparable
Cartesian robot systems. Their single pedestal mount requires a small footprint and provides an easy, unhindered form of mounting. On the other hand, SCARAs can be more expensive than comparable Cartesian systems and the
controlling software requires
inverse kinematics
In computer animation and robotics, inverse kinematics is the mathematical process of calculating the variable joint parameters needed to place the end of a kinematic chain, such as a robot manipulator or animation character's skeleton, in a g ...
for
linear interpolated moves. However, this software typically comes with the SCARA and is usually transparent to the end-user.
Sankyo Seiki,
Pentel and
NEC presented the SCARA robot as a completely new concept for assembly robots in 1981. The robot was developed under the guidance of Hiroshi Makino, a professor at the
University of Yamanashi.
Its arm was rigid in the Z-axis and pliable in the XY-axes, which allowed it to adapt to holes in the XY-axes.
Animations
Source:
File:SCARA right.gif, Direct kinematics of a SCARA robot
File:5R robot inv kinematics.gif, Inverse kinematics of a 5R parallel robot
File:5R robot.gif, Direct kinematics of a 5R parallel robot
See also
*
Articulated robot
*
Schoenflies displacement
References
External links
Why SCARA? A Case Study– A Comparison between 3-axis r-theta robot vs. 4-axis SCARA robot by Innovative Robotics, a division of Ocean Bay and Lake Company
{{Robotics
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Robotic manipulators
1981 in robotics