Servo motor speed given problem - Database & Sql Blog Articles

Single-chip microcontroller STM32L151CCU6

Probe current and voltage pin, 420*4450 head diameter 5.0, overcurrent current and voltage pin

Mobile phone crystal 3.2*2.5mm 3225, 26M (26.000MHZ), 7.5PF, 10PPM, 20PPM, 30PPM

SMD aluminum electrolytic capacitor

1. The servo system regulates the motor speed through a speed loop.

2. The motor speed is determined by the voltage in DC motors and by the frequency in AC motors.

3. Therefore, the output from the speed loop regulator controls either the frequency of the AC motor or the voltage of the DC motor.

4. How does the speed loop detect the motor's speed? It relies on an encoder for feedback.

5. The encoder's feedback pulse frequency equals the encoder resolution multiplied by the motor speed.

6. This means that the motor speed is directly proportional to the frequency of the encoder’s feedback pulses.

7. In other words, the speed loop uses the frequency of the encoder pulses as its feedback signal.

8. To set the motor speed, you must provide the frequency of the encoder pulses.

9. If there is no direct setting for the encoder’s pulse frequency on the control panel, the only option is to adjust the command pulse frequency, which is referred to as S1 by the user.

10. The electronic gear ratio is calculated as the encoder resolution divided by the number of command pulses per cycle.

11. Therefore, the number of command pulses per cycle equals the encoder resolution divided by the electronic gear ratio.

12. Command pulse frequency equals the number of command pulses per cycle multiplied by the motor speed.

13. Since the encoder pulse frequency is equal to the encoder resolution multiplied by the motor speed, we can conclude that:

Command pulse frequency = Encoder pulse frequency / Electronic gear ratio

14. By setting the command pulse frequency, you are effectively setting the encoder pulse frequency, and thus the motor speed within the speed loop.

15. Therefore, the user only needs to set the command pulse frequency S1 on the operation panel to control the motor speed in the speed loop.

16. This process doesn’t require changing the pulse equivalent, the electronic gear ratio, or the number of command pulses per cycle that have already been configured.

17. The maximum command pulse frequency is limited by the rated frequency of the position loop counter or the nominal frequency of the PLC pulses.

18. As a result, the upper limit of the command pulse frequency corresponds to the maximum motor speed.

19. To determine the command pulse frequency:

1) Command pulse frequency = Number of command pulses per cycle × Motor speed

2) Given the motor speed in revolutions per second, the command pulse frequency can be easily calculated.