Bandwidth consumption by remote-controlled robots

Commercially available systems are standardised now for this type of thing. You`ll find Infra Red is mainly 7nm and Ultra Sonic 40KHz (etcetera)! Your own custom system for such simple control could be almost anything.

Yeah, but what's theoretically lowest rate?

If I use radio/cord remote control device, it's not something, but if I would like, let's say, to control my robot over internet?

Then one could logically infer your bandwidth would be equal to that of the wireless networking technology you're using. About 2.4Ghz for

802.11b/g for example.

Chris

It would depend a little on the size/type of commands being sent, but the bigest factor is the frequency of the commands being sent. Sending 100 commands a second would probably take 100 times the bandwidth that sending 1 command per second would take. The internet has lag times that must be considered if you are trying to control a very active type of robot. Below is a simple servo based pan/tilt cam that would give you an idea of internet control on a cable modem setup. The minimum bandwidth would depend on how much control delay you could tolerate.

You'll find your IR wavelength is mainly out by two orders of magnitude ;-)

The lowest rate depends on how tolerant you are to delay. Can you wait

1 second for your STOP command to actually get to the robot? If yes, then maybe you could get away with 10 bits per second.

I would say there is no point it trying to get your bit rate below 100 to 300 bits per second if you are using the internet due to overhead related factors.

-howy

Well why didn`t you say 3.8um with 500us pulse bandwidth then?

Could I have been thinking about Microwaves instead (digging myself deeper...)

----------------------------------------------------------------------- Ashley Clarke

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Whatever frequency you use, the bandwidth will be about half of it. (Erm Right?)

----------------------------------------------------------------------- Ashley Clarke

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I tend to see internet connection as major bottleneck. It has its unavoidable lags no matter what bandwidth you have. On the other hand, imagine one server serves program for many robots, let's say for 1000. than 300bits per second (40 bytes, to keep numbers round) implies

40kB/s. Very viable so far... But then, you have to add stuff you send back. It doubles this rate. Then, if you want your robot to recognize faces, etc, you add video traffic. KABOOM - traffic is exploded. Then, you want robot to talk (adding audio traffic). What do we have now?

-Hey robo, what's you'r name?

-Hello.

-You're not really fast, right?

-Call me Sunny.

-Can you make me a coffee?

-No, my hardware is times and times faster than yours.

7 nm IR??? More like 700! You must have mixed up your hard x-ray source with your IR source. Wonder what sort of sensor you are using! I'm glad you are not my physician.

Cheers!

Sir Charles W. Shults III, K. B. B. Xenotech Research

321-206-1840

No relationship. Voice messages require only about 4-10 khz BW, no matter how they're sent - over phone lines or 900-mhz cordless phone. Radio music is maybe 20-khz BW, whether AM at 1600-khz, or FM at

88.5-mhz.

It depends. The more on-board computing power you have, the less bandwidth required for comms between robot and base. Eg, the gecko systems robot uses 57,600 bps for control comms, and it does a lot ...