Curve-controlled acceleration
Servo and main spindle motors can perform better with digital drive technology than with analogue technology, i.e. the motors can be operated closer to their performance limits.
To fully exploit a motor during acceleration, it can be operated at its commutation limit curve. This curve defines the maximum available torque as a function of speed. It has been observed that motors can sometimes output 1.5 to 2 times the torque at up to half the nominal speed compared to the nominal speed.
For an endlessly rotating spindle, setpoint generation can be set to such a speed-dependent acceleration curve.
Typically the acceleration curve is constant in the lower speed range and then drops after a speed limit nlimit according to a specified curve:
As this acceleration curve varies for individual spindle gears, a corresponding data record must be provided for each gear.
Two methods are provided to define the acceleration curve and they can be selected by the machine parameter P-AXIS-00202.