For my project I need a pan-tilt system able to provide 0.1° resolution or better.

I do have my own solution based on stepper motors with planetary gear for low backlash and 0.05°.

However, I designed the PTZ mechanics and it is not very stable. Also the final goal is to be outdoor system, so I am curious if I can use off the shelf outdoor PTZ. I tried a few manufacturers and so far the low end systems use PMSM, maybe worm gears.

Tried to look for info here and on Internet regarding PMSM control. I see the main discussion is regarding the speed control of the motor. For the off-the-shelf PTZ it is fixed already in the order of 1 - 10°/s. My question is what would be the smallest possible "step", angle to move?

For example, I can easily control that with the stepper, stable around 50-100 Hz. I was reading about servo motors (initially thought this is what PTZ uses) and saw commands work on 50 Hz so I assumed I could control at such pace.

For PMSM I could not find info, so I decided to ask here.

Let's assume I have a PTZ with 1°/s speed. I will control it using my STM32 MCU. As I imagine it, I would send PELCO-D command for speed/direction, then I can send command to stop. Question is what would be a feasible time between the commands? For example, having 1°/s speed, If I send command to move and after 10 ms delay I send stop command, would that (ideally) lead to 0.01° accuracy? I say ideally since I guess we still have inertia on start/stop to take into account. Would faster command decrease it further? Which reminds me if someone has idea about the equations to calculate necessary movement? I found some before for steppers, I am not sure if I can use the same algorithm here...



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