We all know the three-ring, in which the current ring is adjusted by the driver itself, we need to do the work is to adjust the outside speed ring and position ring, inside this is the classic PID control,
When we carry out positioning control, the speed curve and displacement curve will be planned in advance, and then the PLC is sent to the servo driver after calculation, and the driver controls the motor to move according to the planned curve.
This is a little contradictory ah, it is supposed that no matter how good the PID control is adjusted, the system output tracking system input always has a period of time to delay to stabilize, such as step input, system output can not be immediately reached, there will always be a certain time to stabilize tracking,
The question comes, the time velocity curve, displacement curve and servo driver control motor of the positioning control configuration in PLC can be completely tracked and replicated? For example, in my PLC, I plan a fixed length value of the speed curve with acceleration and then uniform speed and finally deceleration. Can the servo drive control motor completely follow the planned curve? If so, wouldn't that go against the PID principle? pID doesn't teach us the ability for output to immediately track input.
