Control.com - Nerds in Control

Hi,

I've been researching various sensorless BLDC motor control designs and have gathered a lot of information (maybe too much).

The motors will be driving propellers for a UAV so I want a fast, accurate speed resposne. Here is the question - what is the best control method for achieving fast, accurate speed response for both increases and decreases in speed?

At the moment I am envisaging a simple controller that calculates commutation points from the back emf. As well as the commutation points a speed estimate is calculated and compared with the desired set-point and put into a PID controller. Based on this the PWM control to the 6 switch inverter is modified.

How would this handle decreases in speed? Is it worth looking into driving the speed of the propeller down to increase response as apposed to letting it reduce to the desired speed by having a very low PWM duty cycle?

Does anybody have any suggestions for the controller methodology? Should I be looking at direct current controllers for such an application, and if so where can I find some introductory information on them?

I assume the load torque of a propeller would be fairly constant over the speed range. Anybody got any ideas of areas where I should be looking?

Dear sir,

Our company is a R&D Unit having an experience over 15 years in BLDC Motors and their controllers (with all requirements which you want). From our past experience we handles many customers of USA, Italy, Brazil, etc.

For further information go to our company website at http://www.skdynamics.com

Thanks,
S K Dynamics
INDIA