Baldor NextMove BX, Руководство по установке

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NextMove BX Installation Manual
44
MN1258V4 08/2000
If the motor does not move, check the following:
•
The amplifier is enabled.
•
There is a voltage output from the output.
4.4.1 Tuning a Servo Drive
At the lowest level of control software, instantaneous axis position demands produced by the
controller software must be translated into motor demands. This is achieved by closed loop control
of the motor. The motor is controlled to minimize the error between demand and actual position
measured with an incremental encoder.
Every 1ms (or optionally 500us or 250us using the
LOOPTIME
keyword) the controller compares
desired and actual positions and calculates the correct demand for the motor. The corrective signal
is calculated by a PIDVFA (Proportional, Integral, Derivative, Velocity Feedback, Velocity Feed
forward and Acceleration Feed forward) algorithm.
Control could be achieved by applying a signal proportional to the error alone, but this is a rather
simplistic approach. Imagine that there is a small error between demanded and actual position. A
proportional controller will simply multiply the error by some constant and apply the result to the
motor via an amplifier. If the gain is too low, then the motor will not hold positional. As the gain is
increased, the motor will present more resistance to positional error, but oscillations will increase in
magnitude until the system becomes unstable.