How to modify the TCP to have X axis aligned with the nozzle (Kuka Welding)
By default, in Robotmaster’s tool frame Z+ points out of the spindle or welding torch.
It is not possible to have Robotmaster calculate the trajectories with the X aligned with the tool pointing out. It is possible however, to transform the TCP coordinates to match the Kuka TCP via the output code.
Step by Step Guide:
Similar to Figure 1, we want to go from “1” to “2”, to do this, we have to do a Ry 90 rotation and then a Rz 180 rotation. (Rxyz):
Figure 1: Before and After TCP orientations.
Note: a Rz 180 and a -90 Ry rotation is equivalent (Rzyx)
To achieve this, we have to transform the TCP using a Rotation Matrix, which we can get from Robotmaster’s Rotation Calculator tool:
Figure 2: Robotmaster’s rotation Calculator tool.
2. Once we have the rotation matrix, we must add it to the V7 .rmcell file as a “Custom Value” by doing the following:
Figure 3: Modifying the .rmcell file, Part 1
Figure 4: Modifying the .rmcell file, Part 2
Warning: The rotation matrix depends on your original tool frame, if your original tool frame is different from the one shown in figure 1, your rotation matrix will also be different.
Values added in the .rmcell:
Custom Value: _FEATURE_ToolFrameExtraRotationMatrix3X3
Rotation Matrix: 0,0,1,0,-1,0,1,0,0
3. With this added, load the processor and generate the code. This should change the coordinates for the TCP and all the points.
Warning: Robotmaster’s simulation will not reflect the modification applied to the TCP. The simulation will show Robotmaster’s default TCP orientation.
Warning: We strongly recommend generating robotic code without the custom values added first, and then generate code with the custom values added. This way, the generated codes can be compared.