C2000WARE-MOTORCONTROL-SDK: dual_axis_servo_drive_fcl_qep_f2837x.projectspec

Hi,

The subject matter expert is out of office due to holiday break. Please expect response by 1st week of January. Sincere apology for inconvenience.

Regards, Santosh

Hi,

Is the expert back from vacation？

Both are the similar, just change FCL_PI_MACRO() to inline runPID() for speed regulator. You can find the source code for runPID() in pid_grando.h.

I don't understand the code of this runPID() . Is there any documentation to help me understand the code of this function.

What I understand is that this code is not the usual incremental PID or positional PID.

How can I adjust the parameters to make my system correspondingly faster and more stable

Take this function for example：FCL_PI_MACRO(pMotor->pi_id)

#define FCL_PI_MACRO(v) \
{ \
v.out += (v.err * v.Kerr) + v.carryOver; \
v.out = (v.out > v.Umax) ? v.Umax : v.out; \
v.out = (v.out < v.Umin) ? v.Umin : v.out; \
} 

pMotor->pi_id.out = pMotor->pi_id.out + (pMotor->pi_id.err * pMotor->pi_id.Kerr) + pMotor->pi_id.carryover;

pMotor->pi_id.Kerr=(pMotor->pi_id.Ki * 0.5F) + pMotor->pi_id.Kp; 

pMotor->pi_id.carryover= (pMotor->pi_id.err * pMotor->pi_id.KerrOld)  = pMotor->pi_id.err *((pMotor->pi_id.Ki * 0.5F) - pMotor->pi_id.Kp);

Through the above calculation, the following conclusions can be obtained：

pMotor->pi_id.out = pMotor->pi_id.out + Ki*err;

Can we assume that this PI has nothing to do with Kp?

I haven't installed the software yet, I will.

Yanming Luo said:

No. Kp is including in Kerr, please have a look at the FCL_runPICtrlWrap() function.

Yes，Kp is including in Kerr ，but Kp is including in carryover too,so you can look at the following formula：

shang tao said:

pMotor->pi_id.carryover= (pMotor->pi_id.err * pMotor->pi_id.KerrOld)  = pMotor->pi_id.err *((pMotor->pi_id.Ki * 0.5F) - pMotor->pi_id.Kp);

So I calculate that Kp is eliminated.Did I miscalculate？

Does the PID of the current loop have topology documentation similar to that of the speed loop？

Yanming Luo said:

pid_grando.pdf

Could you please instruct me how to tun the gains (Kp and Ki )of the PI regulator？