[Feature request] Use multiple position sensors (SIN/COS + AS5048A) simultaneously

[totosolat]

Hi,

I use a VESC 6 edu for controlling robotic actuators and I would like to do the following: -Use SIN/COS sensor on the rotor side for FOC control (which I have already done, it works well) -Use an AMS AS5048A as absolute output position (after a reduction ratio or 100) in order to know the output absolute position I don't have with the SIN/COS on the rotor side. I only need to be able to access this position value from CAN and/or application, not for FOC control. It could also be used only one at sartup to get absolute output position only once and use SIN/COS sensor after getting absolute reference.

Both configurations work fine but I can't make it work together at the same time, the configuration tool does not allow this.

Using only the output AS5048A for FOC and absolute output position is not a good option since the limited electric angle resolution and errors due to the reducer does not allow for good FOC control.

Thank you

[Teslafly]

This seems like a rather unique use case and I would encourage you to try and implement this feature on your own if it is important to you. Otherwise if your gearbox doesn't have a lot of backlash you can use the multiturn angle division setting in the pid tuning as your gearbox ratio to map the motor multiple turns to your output angle.

[totosolat]

Hi,

Thank you for your answer. I will have a look at this. I already use the multiturn angle division for output position control. The remaining problem is that If I use a sensor only on the motor side, I have a absolute measurement of the rotor position but I don't know the absolute output position of the actuator. At the moment, I need to place the actuator at a known position at startup in order to control the absolute output position based on rotor position.

[Jerry3012]

I have exactly the same needs and may I ask if you have already started working on this feature?

[totosolat]

Yes, I am working on it right now. -We are using sin/cos encoder for FOC control -We are developing custom user app which reads the AS50xx encoder. We use this encoder value to set the PID pos offset parameter. -We also created a lisp function to access the encoder value.