Hello everyone,
I did a hover test and little bit of pitch roll and yaw movements in Loiter mode to find out stability and oscillations. I observe that RATE.POut is continuously at 0.05 in hover and later reaches 0.2 when very harsh accelerations and decelerations are applied. After reading Arducopter docs and discourse discussions from other people and learnt that this offset corresponds to 5% of weight imbalance in pitch. I tried lot of things to reduce this imbalance but according to design constraints it is not possible to improve beyond this value of weight imbalance. I just want to know whether this is acceptable in long run or not in applications where the drone is not pushed hard (surveillance, delivery) as compared to Racing quads.
Log attached below. https://drive.google.com/file/d/1RzLJ1BUq7JMZDSgj8ZBtF-JNNhdvBG-c/view?usp=sharing
@Anubis I have went through few of your discussions related to this topic. Can you please have a look at this?
As we do more high speed missions does the RATE.Rout, RATE.Pout etc tend to increase?
What ultimately matters is whether your motors are maxing out or bottoming out when the drone is fighting wind or doing maneuvers, because that is when you will start to lose control authority. If your motor outputs never saturate with a 5% imbalance, then you’ll be fine.
@Anubis Thank you for your comments.
I had one doubt though. Why it is said that RATE.Pout/RATE.Rout should be less than 0.1
What does it mean if that value is 0.2
That number can be understood as % effort. So a 0.1 during a stable hover means that the flight controller has to use 10% of its pitch control authority to maintain attitude. “It should be less than 0.1” is just a rule of thumb and doesn’t have any real meaning besides being an indicator that there might be something wrong with your hardware configuration if you’re expecting it to be well-balanced. It can be anything really, as long as you’re sure that the motors won’t run out of headroom during the kind of maneuvers you’ll be performing.
Understood. Thank you @Anubis for clearing the doubt. I am sure that there is headroom for my motors and also no significant noise seen in filter review tool.
If i get any doubt i will post a log here for review tagging you.