Wake and Shake
One of the basic functions in the drive of a brushless servomotor is the commutation. The commutation is the current transition of one winding of the motor to the next winding. Only in case of a correct commutation time respectively a correct commutation angle there is correct synchronism of the motor with perfect efficiency and minimum thermal load.
There are different possibilities to evaluate and adjust the commutation angle (parameter MPHASE).
- If the encoder system built into the motor delivers an absolute position value within one turn, you can
- adjust the encoder mechanically. With the preset MPHASE 0 the motor works. This procedure is used with AKM motors with Resolver or Encoder.
- evaluate the commutation angle once with the function ZERO. The angle must be stored in the servo amplifier and will be used with every start.
- adjust the commutation angle electronically. The correction angle is stored in the encoder. The servo amplifier works with MPHASE 0.
- The motor makes a small movement to evaluate the commutation angle (Wake and shake, W & S). Can be used with all encoders (see multifeedback ).
- If the motor position is always the same at the restart, (linear vertical axis) you can the commutation angle to start the motor without movement.
- With a special control system.
Servo amplifiers S400/S600 and S300/S700 use the W&S function WSCNFG 0.
Servo amplifiers S300/S700 from firmware 2.53 additionally use the function WSCNFG 1.