Classification By Mechancial Structure |
The following is a popular way of classifying industrial robots according to the mechanical structure. Each has its own set of limitations and benefits. Mechanical structure is one of the important consideration when selection an industrial robotic arm for performing a particular task. |
Cartesian Robot |
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Cartesian robot is form by 3 prismatic joints, whose axes are coincident with the X, Y and Z planes. |
Gantry Robot |
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Cartesian coordinate robots with the horizontal member supported at both ends are sometimes called Gantry robots. |
Cylindrical Robot |
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Cylindrical robot is able to rotate along his main axes forming a cylindrical shape. |
Parallel Robot |
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Parallel robot constitutes two or more kinematics chains between the base and the platform where the end-effectors are located.
Parallel robot is a complex mechanism which is constituted by two or more kinematics chains between, the base and the platform where the end-effectors are located. Good examples are the flying simulator and 4-D attractions at Univ. Studios.
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SCARA Robot |
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SCARA robot is built with 2 parallel rotary joints to provide compliance in a plane. |
Spherical Robot |
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It is still in the research laboratory, the Spherical robot is actually a spherical shape robot, which has an internal driving source. |
Polar Robot |
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Polar robot is able to rotate in two different directions along his main axes and the third joint moves in translation forming a hemisphere or polar coordinate system. |
Articulated Robot |
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Articulated robots are mechanic manipulator that looks like an arm with at least three rotary joints. |
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Simple Comparison |
Configuration |
Advantages |
Disadvantages |
Cartesian coordinates |
3 linear axes, easy to visualize, rigid structure, easy to program |
Can only reach front of itself, requires large floor space, axes hard to seal |
Cylindrical coordinates |
2 linear axes +1 rotating, can reach all around itself, reach and height axes rigid, rotational axis easy to seal |
Can’t reach above itself, base rotation axis as less rigid, linear axes is hard to seal, won’t reach around obstacles |
SCARA coordinates |
1 linear + 2 rotating axes, height axis is rigid, large work area for floor space |
2 ways to reach point, difficult to program off-line, highly complex arm |
Spherical coordinates |
1 linear + 2 rotating axes, long horizontal reach |
Can’t reach around obstacles, short vertical reach |
Revolute coordinates |
3 rotating axes can reach above or below obstacles, largest work area for least floor space |
Difficult to program off-line, 2 or 4 ways to reach a point, most complex manipulator |
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