Which products are affected?
TensionControl template V2.0 + V2.2, DancerControl template V2.0 + V2.2
What happens?
When the gearbox ratio has been changed over by means of the variables g_bGear1 and g_bGear2 the additional torque required for accelerating or decelerating the reel is not precontrolled correctly. In case of the dancer position control the dancer is deflected more strongly when the system is accelerated or decelerated. In case of a tension-controlled winder the web tension is too low or too high.
When does the problem occur?
The problem occurs if the acceleration compensation function of the templates (AccCompensation) is used and at the same time the gearbox factor is changed over.
When it is changed over to another gearbox ratio, the reference of the moment of inertia of the reel compared to the motor shaft changes (JReel; red= JReel / i²). This conversion is not considered in the templates.
Possible diagnostics?
The current motor torque g_MCTRL_nMAct_a and the value of the acceleration compensation g_nMAcc_n shall be more or less equal when a winder is accelerated and the tension setpoint is 0. The two values only differ from the friction torque required. If this is not the case the acceleration torque is precontrolled incorrectly.
Short-term measures/recommendations?
The constant and max. inertia can be identified in case of every gearbox factor possible. As usual the values are indicated in the visualisation 'AccelerationCompensation'.
The acceleration compensation is to be adjusted according to the gearbox change via the g_nVarMInertiaAdapt_a variable.
Evaluation:
In closed-loop controlled systems an inappropriate acceleration compensation is in most cases compensated unnoticed. In case of purely open-loop controlled systems the faulty compensation causes a tensile force variation. Thanks to the additional calculation of the adaptation value the acceleration can be precontrolled correctly.
