Allen-Bradley 1756-HYD02 User Manual page 176

Chapter 4 Geometries with orientation support
176
This robot contains a fixed top plate (Base Plate) and a moving bottom plate (End
Plate). The fixed top plate is attached to the moving bottom plate by three
link-arm assemblies. All three of the link-arm assemblies are identical in that they
each have a top link arm (L1) and bottom link arm (L2).
As each axis (J1, J2, J3) is rotated, the end plate moves correspondingly in the (X,
Y, Z) direction. The mechanical connections of the parallelograms via spherical
joints ensure that the base and end plates remain parallel to each other.
When each top link (L1) moves downward, its corresponding joint axis (J1, J2, or
J3) is assumed to be rotating in the positive direction. The three joint axes of the
robot are configured as linear axes.
The J4 and J5 axes that form the Swing Arm are connected at the end of the end
plate which provides rotation and tilt for the product at the end of the arm.
Some five dimensional Delta robots have a mechanical coupling (gearing) between
the Swing Arm rotation and the tilt movement. When the robot moves only the
J4 axis, it rotates and tilts the swing arm due to internal gearing. To compensate
this tilt effect, the robot needs to move the J5 axis. This relationship is set using
J4:J5 Coupling Ratio and Coupling Direction on the Offsets tab in the
Coordinate System Properties dialog box.
Program the Tool Center Point (TCP) to a (X, Y, Z, Rx, Ry, Rz) coordinate.
Then, the application computes the commands necessary for each of the joints
(J1,J2,J3,J4,J5) to move the TCP linearly from the current (X, Y, Z, Rx, Ry, Rz)
position to the programmed (X, Y, Z, Rx, Ry, Rz) position at the programmed
vector dynamics. Directions of Rx, Ry, Rz orientations at the Base frame are
shown in above image.
In five-axis Delta robots, the End Plate always remains parallel to Base plate (in
XY Plane). As a result, Rx orientation value can only be programed with 0
180 values. Ry and Rz orientation values are programed as fixed frame XYZ
Euler Angles with their range of +/- 90
See also
Establish a reference frame for a Delta J1J2J3J4J5 robot
Calibrate a Delta J1J2J3J4J5 robot
Configuration parameters for Delta J1J2J3J4J5 robot
Identify the Work Envelope for Delta J1J2J3J4J5 robot
Maximum joint limit condition for Delta J1J2J3J4J5 robot
Work and Tool Frame offset for Delta J1J2J3J4J5 robot
Rockwell Automation Publication MOTION-UM002F-EN-P - February 2018
and +/-180 respectively.
on page 177
on page 178
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on
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