Pololu Robotics & Electronics
My account Comments or questions? About Pololu Contact Ordering information Distributors

Jrk12v12 PID parameters for function transfer


Tenho motores da Servocity (servocity.com) e meu modelo é o Motor DC de engrenagem planetária Premium de 624 RPM com codificador. Eu gostaria de estimar os parâmetros desse motor para obter a função de transferência e os parâmetros PID. Aguém tem um passo a passo para eu fazer isso com esse controlador de motor?

Fico grato a quem puder me ajudar!




Unfortunately, our technical support staff can only respond in English. If you can communicate in English, please repost your description of the issue and questions so that we can help you resolve the problem. Alternatively, one of our distributors near you might be able to offer you help in another language.



I have Servocity motor (servocity.com) and my model is the 624 RPM Premium Planetary Gear Motor with encoder. I would like to get the PID parameters for my model and then get my transfer function, could you help me? I also want to know how to apply a step input to get my desired waveform.

I’m grateful to be able to help me!



Thank you for translating your message. How are you planning on using the motor and encoder (e.g. are you trying to do speed control or position control)?



OK friend! I’m trying to do speed control and I think I’ll need position control too. For I am looking for a method of estimating the parameters of my motor and soon after getting my transfer function through an input to the step to observe the behavior of the waveform when estimating a certain target speed, finishing this work I would get the PID parameters of way for my motors.
See this link, figures 13 to 15 which shows the graphs I’m looking for. I’m trying to do these tasks, but I still have not been able to do it.

When I bought my JRK12v12 I thought it would be easier. In fact I still have questions about how to connect the encoders of my motor on this board. Could you help me with some schematic circuit or drawing?
I look forward to your response, very grateful for your attention!



The Jrk 12v12 controllers cannot use the full quadrature encoder signals. The Jrk can use one signal from the quadrature encoder as a tachometer for closed-loop speed control or an analog voltage as feedback for closed-loop position control. In either case, the signal should be connected to the FB pin. Please note that it cannot do closed-loop speed and position control at the same time. You can find more information about the feedback modes and how they work in the “Feedback Options” section of the Jrk user’s guide.

We do not have any specific advice for getting the transfer function for your motor, but you can find a lot of useful information (including tips for tuning the PID constants) in the “Setting Up Your System” section of that same user’s guide.