Advantages and disadvantages of using servomotors with stepping pulses
The advantage of using a step pulse to control a servo motor is greater than the weakness:
First, the reliability is high, and it is not easy to cause a speeding accident. When the servo motor is controlled by the analog voltage method, it is possible to raise the control voltage to a positive maximum value if there is a problem that the wiring is wrong or the component is damaged during use. This situation is very dangerous. This problem does not occur if a pulse is used as the control signal.
Second, the signal anti-interference performance is good. The anti-interference performance of digital circuits is unmatched by analog circuits.
At present, there are some performance weaknesses in the pulsed control of stepper servo motors due to the limitations of servo drives and motion controllers.
First, the pulse working mode of the servo driver can not be separated from the position working mode.
Second, how the motion controller and driver transmit information with a sufficiently high pulse signal. These two fundamental weaknesses make the pulse-controlled servo motor very limited.
(1) The flexibility of control is greatly reduced. This is because the servo drive operates in position mode and the position loop is inside the servo drive. So the PID parameters of the system are very inconvenient to modify. It can be difficult to implement when users demand higher control performance.
From a control point of view, this is just a very low-level control strategy. If the control program does not utilize the encoder feedback signal, it actually becomes an open loop control. If feedback control is used, there are two position loops in the whole system, and the controller is difficult to design.
In practice, feedback control is often not used, but untimely read feedback is used for reference. Such an open loop system cannot be overcome if there is interference on the signal path between the motion controller and the servo driver.
(2) The speed of control is not high.
