Hello, i am newbie in quadcopter.
I have looked on some research paper by google.
Most of those paper mention the PID controller to maintain the motor's speed in order to maintain stability.
My 1st question is: does PID controller is a must to maintain quadcopter's stability?
if yes, why simple PWM to control motor is not enough?
2nd question: most of the board kit available on sale provide accelerometer to measure the pitch, roll and, yaw. Does measuring those parameters related with PID?
I hope someone could enlighten me.
Thank you for you attention.
Replies
The outputs of the PIDs are just some scalar values (4 of them). These are transformed (quite simple linear algebra stuff) to PWMs.
Measuring things does not relate directly to PIDs. It goes like:
- Measure attitude (using gyros and accelerometers to correct drift)
- Compare with desired attitude (using navigation controller output and RC input). This is PID input data.
- Run PIDs
- Transform PID output to per motor output
Regards, Soren