2017 Robogames Ideas

[GhengisDhon]

Robogames 2016 is done and gone.... It was a lot of fun and I felt it went fairly well but its never too soon to start looking forward to next year. We have a lot of ideas to make it even better for next year and I'm sure everyone else does too.

I'm starting this thread to post ideas/suggestions for next year so please keep it to discussion along those lines.

If there's an idea you want to work on just let everyone know your working it and keep everyone updated on progress. Others are free to work on the same idea...

The first idea on R-Team's plate is standardizing the Target plates/filter cards. As was apparent this year, all target plates are not created equal. We plan to

1.) Test the existing configurations of the Tucson plates and Josh Pieper's plate. (The FSR plates are out.)
2.) Test these plates with different configurations - different size piezos, multiple piezos per plate, various mounting configurations
3.) Collect data at various muzzle velocity's and various distance
4.) Collect data at different hit locations on a target plate; corner, edge, center

Some desired qualities of the standard design are:
1.) Repeatable sensitivity at all locations on the target plate from acceptable pellet speeds
2.) Repeatable insensitivity from all other robot vibrations or impacts
3.) Standard mounting rigidity

Maybe some secondary features:
1.) Redundant piezos with a way to see if a sensor has failed
2.) LED hit indicator on the target plate

The second idea is to make the scoring transponder robust to the RF environment of Robogames. It seems daunting, but as Josh pointed out, this is probably a pretty easy fix. We just need to change the code on the transponder so that it keeps a local tally of the hits on the target plate. Instead of transmitting only when it is hit, it periodically sends out its local hit total.

[jpieper]

I've been thinking of several things with respect to the target plates:

Mikhail and I were trying to figure out what airsoft mechanism would allow the FPS to be continuously varied. Then you could use a chronograph and select FPS with moderate precision for a testing or endurance fixture. Is there some gun which already has a continuously variable power, no matter the mechanism? (i.e. a compressed air solution would be fine).

Some of my panels had their piezo delaminate, even when the acetal surface had been abraded, although the ones that delaminated may not have been cleaned with alcohol before rubber cementing. We probably either need a way to validate that panels are working on site, or do some sort of endurance testing to verify they will hold up to repeated stress.

We had LED hit indicators on each plate, but it is tough to make it visible with opaque acetal front plates. I could imagine switching to a lexan front plate, or perhaps using edge emitting fiber optic routed around the plate to make the outside edge be illuminated? The problem with lexan of course, is that it can't be laser cut safely. I don't know of any easily prototype-able transparent plastics that are impact resistant.

I don't think we necessarily have to test many configurations, we just need to find one configuration which meets all the criteria. If one of the existing panels with tweaks can be made to work, we don't have to make a bunch of variants.


w.r.t. the scoring transponder, we were also considering making an nrf2401 variant, just to make the overall cost lower, be able to frequency hop, and be much smaller. No action necessary, but we may post a prototype sometime, and I'd be happy to just make one for everyone for free if it seems like something everyone found useful.

[jwatte]

The problem with lexan of course, is that it can't be laser cut safely. I don't know of any easily prototype-able transparent plastics that are impact resistant.

You can route Lexan/polycarbonate on a tabletop CNC router, or you could perhaps waterjet cut it (that seems like overkill though.)
Lexan/PC isn't as rigid as acetal or aluminum or whatever, though; when I've cut thin bits in the past (1/32, 1/16) I've sandwiched it between spoil boards. (You can cut a whole stack at once this way, though!)

we were also considering making an nrf2401 variant

I will say this again :-) ESP8266 is cheap, flexible, easy to program, and doesn't require a custom base station. The ESP-8622-12 also ha enough I/Os that it could be the main controller for the board, integrating everything into one.

If we use that, we could conceivably even define a packet format that lets contestants add payload data for telemetry and even control to it. I e, the first N bytes are contestant ID, current score, and checksum, and the following M bytes can be custom, we could have the serial port on the ESP spit out (and receive) those extra bytes for use by the 'bot and controller, and we could use UDP broadcast to let everyone easily listen to it. (Both scoring system and control system at the same time.)

[tician]

I will say this again :-) ESP8266 is cheap, flexible, easy to program, and doesn't require a custom base station. The ESP-8622-12 also ha enough I/Os that it could be the main controller for the board, integrating everything into one.

If we use that, we could conceivably even define a packet format that lets contestants add payload data for telemetry and even control to it. I e, the first N bytes are contestant ID, current score, and checksum, and the following M bytes can be custom, we could have the serial port on the ESP spit out (and receive) those extra bytes for use by the 'bot and controller, and we could use UDP broadcast to let everyone easily listen to it. (Both scoring system and control system at the same time.)

Which is why I should get back to work on YETIS, if only my brain would be more cooperative. Think I might need to hack apart one of the crap shocking cellphone toys I bought years ago to give me a jolt when my depression/apathy makes me not want to get up. Far more entertaining would be Ripley carrying a cattle prod while riding on mynyr with its 4S 20Ah LiFePO4 battery, but that would require a lot more work I've not been able to make myself do yet. Would also be nice if hobbyking would finally restock certain 2.4kW out-runner and 3.0kW in-runner motors.

[ArduTank]

A dremel also works well for Lexan/PC/Acrylic. My local Menards sells small pieces that I have used before. (one is the case window of my PC)

I use either the plastic abrasive wheel or the carbide cutter/shaper plastic wheel found in the extended kit. Or at a hardware store. Both use the Ez-lock manderel.

Would either of those motors be one of the house brand Donkeys, Tician?

[artans]

RoboGames is generally very busy on 2.4 GHz. All the combat robots use 2.4 GHz RC Controllers, not to mention the event WiFi and spectators that use bluetooth and mobile hot spot devices. It's hard to simulate RoboGame's RF environment. Its probably best find a option that uses another ISM band like 433 or 900 MHz, lessen the chance that we run into interference issues. We can still try the ESP8266 or nrf2401 versions of the transponders, we won't know until we test it out.

I got pretty lucky while competing to not run into severe interference issues this year, my controller XBEEs (was using band 20 (0x14)) only cut out at most 10 seconds during matches.

I used Loctite G02 as the adhesive to glue the piezos to acetal/delrin, it held out pretty well. I hit about every mech's target plates to do final qualifications and checking target plates before matches, felt like I had the most sensitive plates.

[jpieper]

RoboGames is generally very busy on 2.4 GHz. All the combat robots use 2.4 GHz RC Controllers, not to mention the event WiFi and spectators that use bluetooth and mobile hot spot devices. It's hard to simulate RoboGame's RF environment. Its probably best find a option that uses another ISM band like 433 or 900 MHz, lessen the chance that we run into interference issues. We can still try the ESP8266 or nrf2401 versions of the transponders, we won't know until we test it out.

This is why I'm not very excited about an ESP8266 solution. I think the 2.4GHz range can be fine, assuming you control things at the link layer and design an appropriate protocol. With the ESP8266 you're stuck with the wifi protocol, which is going to have a terrible time in challenging wireless environments.

While seemingly appealing, I don't think it is a great idea to try and let competitors tunnel additional information over the scoring system. It has a hard enough time being reliable without additional complications.

I think the existing xbee solution would be just great with different transponder software. If that were changed, my only gripe is the size of the overall transponder + xbee assembly.

[ArduTank]

What about these?

https://www.sparkfun.com/products/9099

It should be a direct drop in, with minimal configuration. 900 MHz too.

[GhengisDhon]

I think the 2.4GHz range can be fine, assuming you control things at the link layer and design an appropriate protocol.

That's my opinion also. Better to stick with the Devil you know... Also all the existing mechs have the XBee transponder already integrated into their design.

As for letting contestants modify the format coming back (such as in the ESP8266 solution), I'm against that for the scoring system. Contestants might inadvertently (or advertently) modify the code giving themselves a disadvantage/advantage.

We've also discussed the Xbee Pro as ArduTank suggests. Its not clear (at least to me) if its a direct drop in placement. We might experiment with them though.

[JoeyFitzp]

What about these RFBees. http://www.ebay.com/itm/RFbee-V1-1-R...oAAOxyrrpThalr They operate at 868Mhz & 915Mhz and are suppose to be direct drop in replacements.