MCT8316A: How to improve speed response of acceleration and deceleration;

Kenji

Part Number: MCT8316A

Hi Team!

I want to improve speed response of acceleration and deceleration.
I re-write the value of CL_ACC and CL_DEC of CLOSED_LOOP1 register, but not work.
No speed change can be seen even if the value was re-write.

Are there any registers that need to be rewritten at the same time?

Also, is there a PID parameter for speed control on this device?
I'm using RTM devices for test.

over 3 years ago

0 Vishnu Balaraj over 3 years ago

TI__Mastermind 24415 points

Hi Kenji,

Thanks for posting your question in MD forum. Please note that CL_ACC and CL_DEC will not work when speed loop is enabled. Speed response in speed loop will depend upon Speed loop PI controller gains Kp and Ki. Please try to tune Kp and Ki to improve the speed response time. You should be able to find these parameters under "Control configuration - Closed loop" section in the "All tunings page".

Regards,

Vishnu

0 Kenji over 3 years ago in reply to Vishnu Balaraj

Intellectual 530 points

Hi Vishnu Balaraj-san

I'm referring to the latest documents of the device, but I don't know how to set the PID because
there seems to be a miss writings on the documents.

ex.) I refer "MCT8316A tuning guide" but, I can't find the [SPD_LOOP] in "MCT8316A" data sheet.

What should I set in actual for test PID params?

+1 Vishnu Balaraj over 3 years ago in reply to Kenji

TI__Mastermind 24415 points

Hi Kenji,

This is a typo. Correct bit field name is SPD_LOOP_EN. This bit enables/disables speed loop. Tuning speed loop Kp [SPD_LOOP_KP] and Ki [SPD_LOOP_KI] is experimental. Start with a lower Kp and Ki and keep changing the values until the closed loop speed looks stable.

Regards,

Vishnu

0 Kenji over 3 years ago in reply to Vishnu Balaraj

Intellectual 530 points

Hi, Vishnu Balaraj

So, which register have [SPD_LOOP_EN] register field?
I want to know that, because I can't search in the document.

+1 Vishnu Balaraj over 3 years ago in reply to Kenji

TI__Mastermind 24415 points

Hi Kenji,

Correction! Speed loop can be enabled in CONST_SPEED Register. Check section 8.7.1.8 (Page 117) in the datasheet.

Regards,

Vishnu

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MCT8316A: How to improve speed response of acceleration and deceleration;