[SamuelEStreamline]

Hello,

I'm getting an issue where a linear move to a joint target does not move the robot to the correct joint target and also does not flag a reach error.

I've attached an example simulation file.

If you run the TRIM_WIRE_C2_1 program, the last instruction tells the robot to move linearly to target WR_C2_1.

Target WR_C2_1 is a joint target with the following joint values:

Code:

106.300000, -10.800000, -56.000000, -180.000000, 34.200000, 163.700000

However, when the TRIM_WIRE_C2_1 program is executed, the final robot joints are:

Code:

106.300000, -10.800000, -56.000000, 0.000000, -34.200000, -16.300000

Can you explain why the robot is not moving to the correct joints?

[Albert]

Robots can't cross a singularity while performing a linear movement. For linear movements, the robot must maintain the current robot configuration. Among others, this means that joint 5 will not cross 0 deg because this means it would cross a singularity.

If you want to change the configuration you should first perform a joint movement to a joint target with the desired configuration (for example, flip axis 5), then you can perform linear movements from there on.

There are some exceptions for robot controllers where they can avoid singularities but they alter the linear movement by adjusting the orientation of the tool along a linear movement.

With most post processors in RoboDK (including the Fanuc post processors), when you generate a linear movement the output is usually the target pose even for joint targets. This should give you the same result you see in the simulation.