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jakesee
Oct19-10, 02:12 PM
Hi,

Anyone has had experience with UAV control/signal design can tell me what is the typical flight speed (surveillance UAV), control range, link speed and control delay like?

(Sorry, I am not a very good engineering student, furthermore control and signal not my discipline... I can only write decent software.)

I am writing a software for a base station to transmit signals at roughly 20Hz i.e. every 5ms transmit a position set point. The UAV has an on board GPS which will transmit its position to the base station but I read that GPS max rate is 1Hz. I could also transmit a "time" data from both sides to get the elapsed-time...

At 100km range away from the base station a wireless link is theoretically 30 microseconds.
total delay = RTT 60microsecs + BW 5ms (base station) + BW 1s (GPS) = 1.005033s
UAV speed = 300km/h = 83.33m/s
error = 83.75 m
Is this calculation correct?

Thanks in advance for any help.

es1
Oct19-10, 04:56 PM
I am not familiar with UAVs but 1/20Hz = 50mS, not 5mS.
Also, a signal traveling 100Km in 30uS seems a bit fast to me. This is 3E9 m/s no?

jakesee
Oct19-10, 05:54 PM
@es1

looks like i am bad at math as well.. haha..

yea 20Hz = 50ms and the signal is at theoretical speed of light for wireless transmission.

BUT... that's why I am asking, i suspect in practical situations, the range and speed are all affect, so if anyone know the practical values, i'd appreciate much. And also, say, if my calculation is correct (not in the math, but in the theory)

Thanks!