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CHAPTER 7 – Programming
SMT-BD1/t
During a tension control sequence execution, the gearing ratio gain calculation is only performed when
the tension set point error is lower than the tension error tolerance parameter value (TER output
activated). During a torque control sequence execution, the gearing ratio gain calculation is only
performed when the torque set point value is reached (TER output also activated).
The ratio init sequence allows to calculate the gearing ratio gain value for a tension control application based on a
dancer feedback. This sequence must be executed before entering a variable diameter tension control sequence
when
Gearing ratio adaptation by line encoder
operation is selected, in order to correctly initialise the gearing
ratio gain calculation procedure before starting the material running.
4.2 - Torque set point ratio adaptation
The amplifier torque set point ratio is only valid during the Torque sequence execution. The other control
sequences and the "Jog" mode are not concerned by the torque set point ratio value. At the amplifier power up,
the torque set point ratio value is set at 1. During a Tension, Speed 1 or Ratio init sequence execution, the torque
set point ratio value is continuously updated according to the speed gearing ratio gain value on the following way :
Torque set point ratio = Spool diameter ratio / Speed gearing ratio gain. During a Torque sequence execution, the
torque set point ratio value can be calculated on various ways according to the unwind/rewind application. The
Torque sequence parameter setting allows to select the most appropriate calculation method as described below :
When
Constant set point ratio
is selected , the sequence
Torque set point ratio
parameter value is
giving the amplifier torque set point ratio value to be applied during the complete sequence execution. If
the sequence
Torque set point ratio
parameter value is set at 0, the sequence is started with the
current amplifier torque set point ratio value (final value of the former sequence) and this value is
maintained during the complete sequence execution.
When
Set point ratio modulation by diameter sensor
is selected , the amplifier torque set point ratio
value is continuously calculated according to the spool diameter value during the sequence execution. In
this case, the effective diameter value source can be either the current analog input 2 (ANin 2) voltage
value or the current diameter value received via the PROFIBUS process data words depending on the
Amplifier configuration
parameter.
When
Set point ratio modulation by line encoder
is selected , the amplifier torque set point ratio value
is calculated according to the encoder/motor speed ratio during the sequence execution. In this case, the
sequence
Torque set point ratio
parameter value is giving the amplifier torque set point ratio value to
be applied at the sequence start. If the sequence
Torque set point ratio
parameter value is set at 0, the
sequence is started with the current amplifier torque set point ratio value (final value of the former
sequence). The amplifier torque set point ratio calculation by the encoder/motor speed ratio is only valid
when the material is stretched. During the torque control sequence execution, the torque set point ratio
calculation is only performed when the torque set point value is reached (TER output activated).
During the Torque sequence execution, the speed gearing ratio gain value is continuously updated according to
the torque set point ratio value in the following way :
Speed gearing ratio gain = Spool diameter ratio / Torque set point ratio.
4.3 - Servo loop gains adaptation
The speed servo loop gains adaptation mechanism is always active when the amplifier is enabled. The
proportional and integral speed regulator gains are both continuously multiplied by the gain ratio value. The gain
ratio value is calculated according to the diameter sensor measurement value in order to adapt the speed servo
loop gain values with regard to the spool inertia value. This allows to maintain the best speed servo loop stability
when the spool diameter is changing. The
Diameter sensor calibration
menu allows to adjust the gains
adaptation parameters according to the spool characteristics. When the
Speed regulator gain ratio
parameter
is set at 1, the servo loop gains adaptation mechanism is disabled. In this case, the speed regulator gains are
maintained at their rated value regardless of the diameter sensor measurement value.