Omron NJ501-4300, Руководство пользователя

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2 Features of NJ Robotics CPU Unit
NJ-series NJ Robotics CPU Unit User’s Manual (W539)
2-3 Ro
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inematics Setting
When there is this difference (between axes A0 and A1) and a robotics movement is executed, there
could be a position jump at the beginning of the movement because same position is output to axes
A0 and A1. This might cause a mechanical shock and damage the robot when there is a high mis-
alignment between the axes A0 and A1.
The system implements two checks in order to prevent possible problems:
a) Commanded axes position error (A0 and A1) is checked against parameter
Err1 before execut-
ing robotics movement commands. In the case commanded position error |A0-A1| is higher than
Err1 , the error “570F Cannot Calculate Kinematics” occurs.
b) Actual axes position error (A0 and A1) is checked against parameter Err2 . When actual position
error |A0-A1| is higher than Err2 , Cartesian position is not valid. In this case Valid output variable
of the MC_GroupMon instruction changes to FALSE.
If the error 570F occurs and the commanded axes position error is higher than Err1 , user can com-
pensate the axes position error using a motion movement instruction to align the position of A0 and
A1 (e.g. MC_GroupSyncMoveAbsolute).
Precautions for Correct Use
• When using Cartesian 3D Gantry Kinematics, you have to configure parameters Err1 and
Err2 . Those default values are 0, but cannot be used.
• Program to stop the robot if MC_GroupMon returns FALSE in Valid output because of actual
position error |A0-A1|.
In case our gantry robot mechanics cannot work in this simple solution, an alternative solution is
used to command the gantry axes (A0 and A1) by using a gearing of the two axes with a torque
feedback of A1 to ensure same position of the axes and equal distribution of torque.
For example, user could implement this solution by:
• Using the Cartesian 3D kinematics (_mcCartesian3DType1) with the axis A1 excluded from the
axes group (A0 as X coordinate, A2 as Y coordinate and A3 as Z coordinate). Applying its own
compensation algorithm to control A1 based on A0 commanded position.
• Using the Cartesian 3D kinematics (_mcCartesian3DType1) with two axes A0, A1 excluded from
the axes group (A4 as X virtual coordinate, A2 as Y coordinate and A3 as Z coordinate). Applying
its own compensation algorithm to control A0 and A1 based on A4 commanded position.
When monitoring Cartesian position of an AxesGroup with Cartesian 3D Gantry Kinematics set by
using the MC_GroupMon instruction, it is calculated assuming that A0 is equal to A1 in terms of
commanded and actual position.