How to measure Torque and RPM of a DC Engine at the same time in Simulink/Simscape

Hey,

I'm operating a DC Engine, which drives a car. I works fine, but I need to know both Torque and RPM of the engine. Using an "Ideal Rotational Motion Sensor" OR an "Ideal Torque Sensor" the results are fine. But when I'm using both sensors at the same time, only one of them is working (Torque).

Does someone have a hint how so solve my Problem?

[Javier External]

Yes i have the same problem too. I would like to know the answer.

[Birdman]

Can you share the simulink model?

[Nicolas Schmit]

Please share the Simulink model. Also, which version of MATLAB are you using?

[Javier External]

I show you a simplify model. If i just want to control a DC motor and I want to see speed(rpm) and torque (N*m)using the two sensors blocks for torque and rotational sensor, i allways have the same problem. One of the signals is 0. (Matlab 2013a)

[彬 魏]

The torque on both sides of the gear is measured simultaneously in simscape, and the result of the torque sensor is faulty

Answer 1

[Franck Donnadieu]

Good evening, I reproduced your model by adding a resistance. Try to separate scopes also. The overview of the results depends on the scale which is adapted to the biggest value (it is possible that on this scale the other value is not visible without making a zoom). ;)

[彬 魏]

The torque on both sides of the gear is measured simultaneously in simscape, and the result of the torque sensor is faulty

Answer 2

[Cyril CRIER]

Hello all, I have the same issue!

I tried the solution of Franck Donnadieu (put a Rotational Friction Block in "Serie" to the R port of the DC motor block), which give me that:

instead of that (basic DC Motor block coming from the command "ssc_dcmotor"):

But I'm still getting this Error message:

I've inserted a simplified model to the post.

Anybody know the trick?

Thanks

[Cyril CRIER]

Edit: I replaced the 2 variables that I had in the Subcomponent by algebraic values.

[Cyril CRIER]

Update: I still get the same error message even when I disconnect the torque sensor:

Zoom on the subcomponent "Sensors Torque/Speed Motor [Nm]/[rpm]":

Here I should have at least the speed...

I have no idea where commes the problem...

[Franck Donnadieu]

Hello Cyril, could you save your model in 2018b version. I can't actually open it.

[Cyril CRIER]

I exported as 2018b version. I hope it works

[Franck Donnadieu]

You make a mistake with the units in the converter (see the error message). Leave the default "1" in the converter, it adapts the unit to the sensor upstream.

[Cyril CRIER]

Really?! what a d**b mistake from my side... I guess I just did a copy/paste.

Thank you very much. This error message disappeared I just have to analyse the outcomes now ;-).

Answer 3

[Vincent Riboulet]

Hello,

The torque sensor should be put in line, exactly like an intensity sensor in the electrical world.

[Leonardo Costa]

Could you explain it with a photo?

[彬 魏]

The torque on both sides of the gear is measured simultaneously in simscape, and the result of the torque sensor is faulty

Answer 4

[Dimitrios Tzerakis]

In my model I used a BLDC, but the ports are essentially the same.

You connect the R port of the BLDC to both the R ports of the rotary and torque sensors.

The C port of the Rotational Motion sensor is to be connected to ground (so that its "parallel" to the motor)

However, as @Vincent Riboulet said, the torque sensor needs to be in series with something. To its C port, you can add an inertia, but I even tried a blank torque source (commented out things) and it worked fine.

I tried @Franck Donnadieu's answer, but the rotational friction kept influencing the output of the torque sensor, so I dont reccommend it. (Idk if its because im using R2020a, but think its worth noting).

I hope you can see the picture of my diagram:

[Dimitrios Tzerakis]

Here's a lower resolution version:

(hopefully its easier to scroll through :)

[彬 魏]

The torque on both sides of the gear is measured simultaneously in simscape, and the result of the torque sensor is faulty

Answer 5

[彬 魏]

[彬 魏]

[彬 魏]

The torque on both sides of the gear is measured simultaneously in simscape, and the result of the torque sensor is faulty

Answer 6

[彬 魏]

The torque on both sides of the gear is measured simultaneously in simscape, and the result of the torque sensor is faulty

Answer 7

[彬 魏]

The torque on both sides of the gear is measured simultaneously in simscape, and the result of the torque sensor is faulty