Super IR

I know some teams have made their IR remotes stronger with multiple LEDs, but what does this mean for the teams like mine using just a normal remote?? Will our signal be drowned out by the stronger remotes?

I hope not… :ahh: that would be a problem for us.

Andy,
My concern from the begining is not how strong signals might override yours but how are teams going to coordinate which command set they use with other teams. If teams are using the same button sequences using the same remote, there will be chaos during the hybrid mode.
Ham radio operators have adopted defacto standards for operating different modes and different frequencies. Maybe we need to make a plan so all teams know what to train their remote for when entering the field. i.e. Blue Team 1 uses the top set of four buttons. Blue Team 2 uses the next buttons down on the remote, etc. That will produce less confusion on the field for those teams that use remotes.

all yall have to do is use a non-standard remote. Manufacturers have already specified which frequencies they use, and if you go with a older remote or one you pull off a non-name brand TV, you should have no problem with interference.
Or you could just hack the remoter and stick on a industrial size IR transmitter:)

We are currently planning on using a non-standard transmitter with 3 LEDs.
It only has 3 inputs, so we might not use it, but it sure looks cool and functions well. We will probably make up a deflector for it to limit exposure to other robots. (most likely a paper towel tube)

I’m not saying what we are using because it is a standard product and if there is more than one other at our regional there WILL be crossover.

Manufacturers have adopted some or all of a standard for IR communications so many remotes use the same codes for similar functions. This allows multifunction remotes to change channels and raise/lower volume on your TV while operating the satelite, DVD, VCR and AM/FM receivers.

We built a custom IR transmitter that uses a single high power IR diode and a collimating lens like described in http://lasertagparts.com/mtoptics.htm . The idea for this was not to use this to send commands to the IR receiver but to detect uniquely modulated reflected IR energy off a track ball and seek the reflected energy. It has promise but it is not there yet mostly because we tried to design our own differential receive signal processing and used a standard set of IR phototransistors with a 5 degree receive pattern and it was difficult to acquire the target. We might throw in the towel on the target designator idea and change the modulation to a standard carrier frequency with a unique bit sequence so it can be used has a high power IR transmitter. If we do that, it will be very directional (at least until it is reflected). It will be interesting to see how much jamming is going on at the competitions. I’m assuming that teams will swap out the IR receiver module for different carrier frequencies but that still may not be enough. We attempted to do some IR spectral analysis by just looking at the frequency domain from our IR photo transistor with a bunch of different remotes including a TV-B-GONE (4 high power IR LEDs) and there are harmonics and spurs all over the spectrum. There do seem to be some nice quiet regions, though and that’s where we have been concentrating.

Andy, we rigged a universal remote with high-output LEDs, and took multiple IR boards and swapped out the IR receivers with those sensitive to different carrier frequencies.

We found that at closer ranges, our high-output remote could be jammed by regular remotes and vice-versa. Our high-output remote had better range than a standard remote, so past a certain point, normal remotes had no effect. However, we found a very popular, normal, bone stock, single LED remote with a 62 foot range, which is already pretty “super” IMO =).

We also found that a remote using a 36kHz frequency can jam one using a 38 or 56 kHz frequency, and vice-versa.

There’s been a lot of discussion on CD regarding IR jamming, and how best to handle it.

http://www.chiefdelphi.com/forums/showthread.php?t=62775&highlight=ir+jamming

We did a test on our robot at our warehouse, where we had a roomba remote and a modded remote that our robot was programmed to work with.

We were able to get a signal up to 70 feet with the modded remote, but as soon as we started firing the other remote, even if it wasnt in the general direction of the robot, it stopped reliably receiving the signal.

my suggestion would be to create a limiter so your robot can only see a small angle of signals, therefore reducing confusion.

Im sure you all already know but with the standard ir board if it receives ANY stray ir from any remote no matter what button was pressed on the other remote or how it was programmed it will stop and do nothing until the air is clear and it receives the one (of four) signal it was looking for.

For trams still using the standard ir board I would suggest some kind of shield that only allows ir to come from the Robocoach corner that you plan to stand in. Our team has an ir resistant cone mounted on a servo using the gyro angle to always point at our robocoach station to try to get a clearer signal.(but we don’t know how well it will work until we try it in the real competition.)

We played with signal modulation and even tryed sonar but we were not able to get a better signal out of anything we tried and ended up resorting back to the origonal ir board.