Which products are concerned?
Library module L_MCProfileGenerator, included in the Software Package as of V3.3
Problem description:
Although jerk-reduced profile generation is used, a profile change leads to an acceleration jump (jerk). For small load inertia, the resulting torque jump at the output may be audible.
When does the problem occur?
When all of the following conditions are met:
1. Use of jerk-reduced profiles in S-profile optimised mode (wSProfileMode=1)
2. A new profile is started in the acceleration phase of a running positioning process.
3. The profile parameter speed of the new profile is higher than the current speed.
4. The profile parameter speed of the new profile is smaller than the profile parameter speed of the previous profile.
Possible diagnostics?
With the GD oscilloscope, you can generate an oscillograph of the internal acceleration (Program_Task1.L_ProfileGenerator1.dnS_AccInternal). The generated signal shows a jump. The acceleration jump leads to a jump of the torque setpoint. Often, this setpoint jump can be heared at the drive (clicks).
Short-term measures/recommendations?
A profile change in the acceleration phase of a jerk-reduced profile should be avoided.
Evaluation
The drive still follows a motion profile with an unsteadiness in the torque setpoint. The effect of the torque jump depends on the load inertia. In most cases, you will only hear clicks in the drive train, the driven shaft doesn't noticeably change its path. Normally, the restriction already occurs during commissioning.
