Hi
We’re using Telega 0.3 on a hexarotor, paired with Tmotor MN501 Kv300 motors.
During flights we noticed that, at certain times, the arm ends enter substantial vibrations that come and go.
The vibrations are similar in appearance to vibrations we encountered when we tried to migrate to Telega v0.6 (back then - the drone arms would enter violent vibrations when crossing ~2000RPM. The phenomenon was then analyzed as related to the lower PWM frequency Telega V0.6 uses, and solved by reverting back to v0.3)
We are using Ardupilot with UAVCAN and therefore blocked from using Telega V1 (which is, of-course VERY unfortunate)
Question is - could the vibration we see be related to the Telega PWM frequency?
Can we change this parameter to test its affect on the vibrations? What are the normal boundaries for it?
We don’t really have exact measurement of the vibration frequency, but the vibrations are visible and don’t look more than single-digit Hz.
From the Ardupilot log it seems that when some of the vehicle’s motors surpass ~2800 RPM - strong arm vibrations are observed.
These aren’t necessarily related to the ESCs, but I’d like to conduct a few experiments to make sure this phenomenon isn’t related to the PWM frequency of the ESCs interacting with other vibrating system components.
My question was aimed at understanding the bounds at which this parameter can be altered and what are the expected side effects of its alteration.
I would say that vibrations under 10 Hz are unlikely to be related to the PWM frequency. It is still interesting to test for it though.
You cannot increase the PWM frequency as it will lead to CPU starvation with many side effects. You can decrease it though by up to about 1.5 times (not more), which will result in: