The advantages of using stepper pulses to control servo motors outweigh their disadvantages.
First, it boasts high reliability and is less prone to runaway accidents. When controlling a servo motor using analog voltage, incorrect wiring or component failure can cause the control voltage to rise to its maximum positive value, a highly dangerous situation. This problem is avoided when using pulses as the control signal.
Second, it has excellent signal interference immunity. The interference immunity of digital circuits is unmatched by analog circuits.
Currently, due to limitations in servo drivers and motion controllers, controlling stepper servo motors using pulse methods has some performance weaknesses.
First, the pulse operation mode of the servo drive cannot be separated from the position operation mode.
Second, how can the motion controller and driver transmit information using sufficiently high pulse signals? These two fundamental weaknesses greatly limit pulse-controlled servo motors.
(1) Control flexibility is greatly reduced. This is because the servo drive operates in position mode, and the position loop is inside the servo drive. This makes it very inconvenient to modify the system's PID parameters. It becomes very difficult to achieve when users require high control performance.
From a control perspective, this is a very rudimentary control strategy. If the control program does not utilize encoder feedback signals, it effectively becomes an open-loop control. If feedback control is used, the entire system has two position loops, making controller design very difficult.
In practice, feedback control is often not used, but feedback is read intermittently for reference. In such an open-loop system, if interference occurs in the signal path between the motion controller and the servo driver, the system cannot overcome it.
(2) The speed of control is not high.
