Torque and Rotational motion sensor in simscape

I have an issue in connecting an ideal torque sensor and an ideal rotational sensor to my BLDC motor.

I saw a lot of question and everybody says that the problem is put in parallel this two sensors. But i cannot fully understand the meaning.

Could you please answer with some photo about the differences?

I add a photo of my situation, honestly I cannot see a different way to use this two sensors together.

Thank you in advance

[Hyunuk Ha]

Simscape is multi-domain plant modeling tool, and each domain has its own variables, which defines power.

In the mechanical rotational domain, two variables are angular velocity and torque.

So, you can detect angular velocity or torque from that domain.

You can refer to the detailed info. at :

https://www.mathworks.com/help/physmod/simscape/ug/basic-principles-of-modeling-physical-networks.html

Answer 1

[Juan Sagarduy]

Hi Leonardo

Torque is a through variable measured with a torque sensor (TS) in series with the shaft of the motor. Speed is an across variable (potential) measured with a rotational sensor (Rot S) in parallel.

In your case, if S is the shaft of the motor, the connection is S - (TS - port R) - (TS - port C) - (Rot S - port R) - mechanical load (inertia, torque source...) (Rot S - port C) connected to a mechanical reference is correct.

Hope this helps out Regards Juan

[Leonardo Costa]

Thank you. I saw the answer only today. The problem of my model is that i don't have any resistant torque. So the motor torque become zero after a transiet.

[彬 魏]

[彬 魏]

The issue was due to the torque sensor being connected incorrectly. In the rotational domain, angular velocity is the across variable and torque is the through variable. The velocity sensor measures the change in velocity across R and C without any torque going through the sensor. On the other hand, the torque sensor measures the torque going through the sensor without any change in velocity across R and C. In the not working model, the torque sensor connection means that the velocity at the junction is the same as the mechanical reference, which is zero velocity. That is why the results are wrong.

If the intent is to measure net torque on the hydraulic machine, then the torque sensor should be connected between the machine and the junction point (like how you would connect a hydraulic flow rate sensor).

This was the cause for a* very specific* model. If you cannot resolve your issue by going through the Simscape documentation and you have a valid license with maintenance, then please contact Technical Support.

Simscape documentation: https://mathworks.com/help/physmod/simscape/

Technical Support: https://mathworks.com/support/contact_us.html