This content has been marked as final.
Show 2 replies

1. Re: Discrete math question  derivatives, integrals, and real time motor control applications
jobi Feb 14, 2018 3:47 AM (in response to user_1409605)Hi,
Are you trying to implement PID loop for motor speed control. These delays have effect and also the motor/circuit lag will introduce more delay in the system. A proper tuned PID can overcome this.
Thanks
Jobin GT

2. Re: Discrete math question  derivatives, integrals, and real time motor control applications
user_342122993 Feb 17, 2018 7:40 AM (in response to user_1409605)In my experience with PID control, the derivative term is usually unnecessary or diminished. In discrete math it is mostly a noise maker, for that it is not worth improving it with 4point approximation. Furthermore, increasing sampling rate worsens derivative term accuracy to practically a noise level. I think that 10kHz sampling rate should suffice for a motor control, while 100kHz is not enough for DCDC converter application.
/odissey1