RC Security Vehicle

ver0776

Active Member
There are many levels to this project, some are feasable and some are out there, but you have to start somewhere.

The problem: No matter how many cameras I have, I miss things and would like to be able to send a camera for close-up investigation when something happens.

Proposed solution: Using an RC vehicle (Like my 1/16th scale tank) and a wireless camera, I could drive around my property and direct the camera for up-close monitoring (PTz provided by turret control- well, not the Z part).

Later, I would like an FM speaker on the tank so I could send TTS and stream voice out of the Tank's speaker.

Later still, an interface to send the RF signals to the RC vehicle should be available from the PC to allow internet control and observation.

Last stages I would like to use my bluetooth GPS and PDA w/WiFi on the tank to update its speed, location and heading back on the PC. This data would be used for autonomous functions, or linking it to the HA system.

I will try to list the obsticles in the order of importance and feasability of overcoming.

1. Vehicle charging itself. You should be able to drive the tank back to the charging station and using trolley car type contacts, or something similar, to connect to power.

2. Camera battery life. A 9-volt wireless camera will only last a couple hours at best. Need to design a relay or something that can cut camera power when not used. Or the dock in #1 should also recharge the camera's 9-volt battery. I have seen some adapters to use more than one battery for longer life. Can a 9.6volt RC battery be used to run a 9-volt camera?

3. Camera range (*HELP*) I am running 2.4g wireless with a $60 antennea upgrade, but the range is still crappy (been forever, but I think it is 20db total). Is there something that can truely provide 150' in any direction? Even through a wall or something. My phone goes to the end of the street, I want my cameras too also. (Don't proposed $2,000 solutions, I like everything on the cheap =) Perhaps the wireless camera transmitter is the problem and I sould use a wired one with a seperate transmitter? Recommendations?

4. FM tansmitters are a joke here, FCC issues I guess. Anyone have a link to a 1000' FM kit or something that is like $200 or less?

5. There needs to be something like the USB-UIRT for RF frequencies that covers the 27-49Mhz ranges (at least) or someone that makes an RC RF controller that has a serial port or something. I do not want to have to use servos to control the sticks on the RC controller! hehe

I am thinking about tethering the thing during initial development, but that does not solve much and would be as limited in range, I just would not have to recharge it. The recharger is about the only thing I think I can make anyways, so no point in skipping it...

Is there any projects already existing that could provide some knowledge in these areas? I would love some links...

Vaughn
 

pete

Active Member
I'd investigate the range (power) of the R/C stuff you plan on using before going to far . . . IIRC, you might run into troulbe with the vehicle being 'shadowed' by other objects, blocking the R/C signal . . .
 

DavidL

Senior Member
Use a standard Futaba style R/C unit. tons of range and FCC approved. Make sure you are not anywhere near an RC flight field.

Use google to search for a PC to R/C transmitter integration solution. Uses the Trainer cord on the transmitter as the interface connection to the PC.
EDIT: http://www.mh.ttu.ee/risto/rc/electronics/pc2rcv2.htm

docking could be like a roomba. make a port for the tank to dock. Maybe a slight downramp to keep the tank pushing to the front even when off against the battery contacts.

Use multiple WiFi access points for increased camera range. They are cheap nowadays.

The software for a hands off system will keep you busy for years.

Overall, a very ambitious project.
 

royalj7

Active Member
ver0776 said:
2. Camera battery life. A 9-volt wireless camera will only last a couple hours at best. Need to design a relay or something that can cut camera power when not used. Or the dock in #1 should also recharge the camera's 9-volt battery. I have seen some adapters to use more than one battery for longer life. Can a 9.6volt RC battery be used to run a 9-volt camera?
9-volts, the cells that are rectangular and have both contacts on one end, are a bit of a misnomer. There actual voltage is around 8.4 V. So, most electronics that use a 9-volt battery run at about 8.4V down to about 5.8V or so. So, depends on what the RC battery is. Do you have a link to the battery?

--Jamie
 

ver0776

Active Member
Well I finally found this guy's web page:

http://www.mh.ttu.ee/risto/index.htm (found it then came back here wishing I had waited for David =) that DavilL recommended. There is a ton of information on that site. I just wish he was in the States.

This is definitly a bigger project than I hoped for. I hope over the next couple of years that PC control is actually addressed by some of the larger RC companies.

I bought the PDA and GPS over a year ago to start on this project, but only now that my HA software is so near to completion am I starting on it. I think I am going to tackle the Recharging station then look at the video research from the above site more closely and see if I can't order some of the stuff that the FCC wouldn't want me to have =)

Thanks for the great info and more URL's are welcome!

Vaughn
 

elcano

Active Member
2. Camera battery life. A 9-volt wireless camera will only last a couple hours at best. Need to design a relay or something that can cut camera power when not used. Or the dock in #1 should also recharge the camera's 9-volt battery. I have seen some adapters to use more than one battery for longer life. Can a 9.6volt RC battery be used to run a 9-volt camera?

You can use any DC-DC voltage regulator circuit to convert the 9.6v voltage to the one required by the camera. There are simple chips that do most of the work (with a few added resistors and/or capacitors). The are several circuits here. However I doubt that the camera would be affected by just V higher than specifed.

3. Camera range (*HELP*) I am running 2.4g wireless with a $60 antennea upgrade, but the range is still crappy (been forever, but I think it is 20db total). Is there something that can truely provide 150' in any direction? Even through a wall or something. My phone goes to the end of the street, I want my cameras too also. (Don't proposed $2,000 solutions, I like everything on the cheap =) Perhaps the wireless camera transmitter is the problem and I sould use a wired one with a seperate transmitter? Recommendations?

If you choose to install more than one Access Point you should try first using at most 3 antennas at non-overlapping channels 1, 6 and 11. If you need a fourth antenna (or more) make sure that the range of one antenna does not reach the range of another antenna in the same channel - so that they dont cancel each other.

Other consideration: I have heard that 802.11b is slower, but have longer reach than 802.11g. Other cocooners might confirm this.

4. FM tansmitters are a joke here, FCC issues I guess. Anyone have a link to a 1000' FM kit or something that is like $200 or less?
Depending on where do you live, you might use a FRS radio with sub-audible tone activation. Other people talking in the same channel will not activate the audio in the car, and since you are much closer to the car than them, your signal will surpass anybodies signal. FM signals do not mix - only the strongest signal is heard at the other end. WARNING: you might hack the mic, speaker and Push-to-talk systems, but NEVER mess with the antenna. Leave the original antenna in its place. Installing an external antenna is against the regulations.

This should get you enough range.

Other ideas:
1. Install IR LEDs with control to be turned on at will - so that you can monitor in the darkness.
2. A tank is a good idea - it will be much easier to drive out of difficult places than a regular car
3. You might want to install gyroscopes to turn on an alarm if anybody raises, kicks, or othewise moves a tank that should not be supposed to be moving. An attack from behind is always a possibility. Motion sensors are also an option.
4. While remote control is always an option, it shoud not be too difficult to program a route for it to travel continuosly. As soon as you turn you alarm to AWAY mode, it would get out of the docking/charger and start the rounds. It will need sensors to make adjustments to the route. This is common robotics practice. However instead of programming everything in the car (or robot), it is much powerfull if you pass the signals to the PC and do the processing there.
 

Quixote

Member
I just skimmed this thread, but I had a similarly lofty ambition a little while back. If only I made another 5k/year! ;)

You should consider that if I was sneaking around in your yard and you sent your bot to investigate, I would pick it up and run away with it. I was considering the same scenario, and also was taking into account that heavier, more powerful robot can reach places more easily without getting stuck. Ideally, you would want something that could ascend/descend stairs and be impossible to lift up and run with.

Look at http://www.robotcombat.com/store.html . They have everything that you would need to build something like that. If I were going to do this I would have a barebones computer onboard with a wireless connection. You could even get a speed controller that hooks up to the computer directly with a serial connection.

The only restriction is that to do it this way is going to cost you an arm and a leg, the bonus is that it could also cost an intruder his legs. ;)
 
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