www.robowars.org

RoboWars Australia Forum Index -> Technical Chat

Gyro setups and details
Goto page 1, 2  Next

Post new topic   Reply to topic
  Author    Thread
Glen
Experienced Roboteer


Joined: 16 Jun 2004
Posts: 9481
Location: Where you least expect


 Reply with quote  
Gyro setups and details

Hi all, for the first time in ages i finally finished my robot before the event and have just spent the day setting it up and practicing driving Smile i think its also worth noting some details about the gyro as they apply to robots as there isnt much info on the subject.

first thing to get out of the way is that with most gyros after power up the robot must be still for about 5 seconds will the gyro sets itself up. if you dont do this the gyro will be more or less useless.

on my GY401 there are two main settings. Limit and delay.

Limit

the limit adjustment basically dictates how much correction the gyro will apply. i believe it goes between 80% and 140%. for low speed 80% is okay but you will find at a high speed turn for example it wont apply anywhere near enough correction, so you need quite a high limit.

on cobra its set a smidge off of the max setting. if it goes into a high speed spin and you let go of the stick it will usually spin the wheels the opposite direction momentarily and come to a stop in about 45 degrees.

Delay

this is a feature for helicopters only really (i should think) its just the amount of time the gyro will wait before applying correction. funnily enough the first few events i used this gyro it was all the way down and was pretty well no help at all.

disable the delay all together for robot use unless you have a drive train with alot of backlash.

there are two toggle switches as well. one sets it for digital servo mode. personally i have it OFF but im not sure what it does or what affect it implies. perhaps it uses feedback or something.. not sure..

theres also a direction switch that sets which way correction is applied. youll work out pretty quick if its in the wrong direction Razz

Remote gain

some gyros have an remote gain feature which allows you to set how sensitive the gyro is. when wound up all the way the gyro will "hunt" alot if you have backlash in the drive system (it will just wobble left and right trying to find the place it things is center).

so you have to find the setting where the gyro will stop the robot from a high turn rate and stop dead straight away without wiggling back and forth.

you also need it in an ivertible robot to turn the gyro off completely as it will apply correction in the wrong direction when upside down so the robot will just spin non stop.. that is bad Razz

Connection

To connect the gyro at first was a bit of a nightmare Shocked but its easy. on the gy type there is 3 wires. one is a signal wire (just has one wire in the plug) that goes into a 3rd channel. this controls remote gain.

the second goes into the steering channel of the reciever (female plug) and the male plug connects to the speed controller input (or IMX mixer if you use one).


Setting up with victors & IMX mixer

this is a hair puller everytime Razz wiring it up is a bit of a prick and calibrating it all More so.. so this is how its done. step by step, not to worry if you dont understand it. this is probably more for my own reference Laughing

hook up is as follows

1) steering channel from IMX1 into steering output (female connector) to gyro.
2) steering input from gyro into steering channel of reciever
3) throttle channel to throttle channel on imx1 as per normal.
4) remote gain into 3rd channel on reciever.

to calibrate

5) default your radios settings (0% trim etc)
6) with the gyro, reciever, imx1 all turned on plug the steering input from the gyro only into the steering channel.
7) adjust the trim on the radio till the LED comes on.
Cool plug the same servo lead into the throttle channel and do the same. dont worry if you have to trim the hell out of it to get it working.
9)plug the rest in as per the wiring instructions
10) turn power on and give the robot a test drive. should drive okay..
11) hold down the calibrate button on the victors and move the throttle and steering channels to their limits
12) release.. LED will flash green if it worked.
13) do the same with the other side

now your robot should work fine in in all directions and achieve 100% power in steering and throttle function. if you dont do this then you will probably not get the most out of your robot Exclamation

any other info on gyros would be good. especially stuff pertaining to positioning within the robot etc..[/b]
_________________
www.demon50s.com - Minimoto parts
http://www.youtube.com/user/HyzerGlen - Videoooozzz

Post Wed Jan 16, 2008 5:02 pm 
 View user's profile Send private message Send e-mail Visit poster's website MSN Messenger
Nick
Experienced Roboteer


Joined: 16 Jun 2004
Posts: 11802
Location: Sydney, NSW


 Reply with quote  

Thanks Glen, excellent work! I was just about up to that part with Scissorhands, so its much appreciated. The digital servo switch just doubles the pulse rate; for ESCs, it doesn't seem to make any difference.
_________________
Australian 2015 Featherweight champion
UK 2016 Gladiator champion

Post Wed Jan 16, 2008 5:34 pm 
 View user's profile Send private message
kkeerroo
Experienced Roboteer


Joined: 17 Jun 2004
Posts: 1459
Location: Brisbane


 Reply with quote  

The digital servo signal can actually be a bad thing for most mixers. The standard servo signal is one 1-2ms pules every 20ms (ie 50Hz) while the digital signal is on pulse every 4ms (250 Hz). I checked this on a CRO. I have 3 different off the shelf mixers and they all glitch when mixing a digital signal and a standard sig (that is one signal from the gyro and the other straight from the receiver). Since my gyro doesn't have a standard output option I have had to build a little converter circuit to get a standard output.
_________________
Get Some!!!

Secretary of the Queensland Robotics Sports Club inc.

Post Wed Jan 16, 2008 5:46 pm 
 View user's profile Send private message Send e-mail Yahoo Messenger MSN Messenger
iluvmatools



Joined: 02 Jan 2008
Posts: 18
Location: blacktown syd


 Reply with quote  

lol wot exactly is a gyro ?? a way of turning the bot?? or for a weapons system????

Post Wed Jan 16, 2008 5:54 pm 
 View user's profile Send private message Send e-mail MSN Messenger
Philip
Experienced Roboteer


Joined: 18 Jun 2004
Posts: 3842
Location: Queensland near Brisbane


 Reply with quote  

The gyro make the robot easier to control. It looks at what you are telling the robot and what the robot is doing then applies a correction when needed.

For example, your robot might be damaged and dragging one corner. The gyro would tell the speed controller on that side to give that motor more power.

There is probably a better explanation on line somewhere.
_________________
So even the rain that falls isn't actually going to fill our dams and our river systems

Post Wed Jan 16, 2008 8:02 pm 
 View user's profile Send private message
Glen
Experienced Roboteer


Joined: 16 Jun 2004
Posts: 9481
Location: Where you least expect


 Reply with quote  

http://www.raptortechnique.com/gy401-jr652.htm

interesting reading.

i have to play with my remote gain setup as the gyro still wasnt 100% in melbourne. its always a struggle between hunting and not correcting properly (it will always not apply enough correction)

so i think im having issues between normal mode and heading lock mode.

possibly because the way the 3rd channel on the dx3 radio works. ill have to play with that tommorow.
_________________
www.demon50s.com - Minimoto parts
http://www.youtube.com/user/HyzerGlen - Videoooozzz

Post Sat Jan 26, 2008 11:01 pm 
 View user's profile Send private message Send e-mail Visit poster's website MSN Messenger
Nick
Experienced Roboteer


Joined: 16 Jun 2004
Posts: 11802
Location: Sydney, NSW


 Reply with quote  

Just for those who lost the manual - its not quite the best documentation on the internet, but a careful read will get you started at least.

http://manuals.hobbico.com/fut/futm0807-manual.pdf
_________________
Australian 2015 Featherweight champion
UK 2016 Gladiator champion

Post Sun Jan 27, 2008 11:09 pm 
 View user's profile Send private message
Glen
Experienced Roboteer


Joined: 16 Jun 2004
Posts: 9481
Location: Where you least expect


 Reply with quote  

got the gyro working in cobra offset to the side finally (chugging through the archaic setup procedure a few times with the trims offset got it working great)

i dont want to have to loose the inverted steering function or gyro remote gain, so i was wondering i could just wire the signal wire for the gain channel into the flip channel so there in parrallel with each other, so that when its upside down (when i beat it back into shape so it can Razz) itll turn the gyro off and flip the steering channel.

think there will be any problems?
_________________
www.demon50s.com - Minimoto parts
http://www.youtube.com/user/HyzerGlen - Videoooozzz

Post Sat Jan 31, 2009 5:02 pm 
 View user's profile Send private message Send e-mail Visit poster's website MSN Messenger
Nick
Experienced Roboteer


Joined: 16 Jun 2004
Posts: 11802
Location: Sydney, NSW


 Reply with quote  

IT sounds plausible, worth testing at least. How did Cobra drive with the offset gyro?

Post Sat Jan 31, 2009 8:05 pm 
 View user's profile Send private message
Glen
Experienced Roboteer


Joined: 16 Jun 2004
Posts: 9481
Location: Where you least expect


 Reply with quote  

its always hard to tell because theres so much slop in the drive system but its much better then without it. and it doesnt seem to over correct to one side like it used to.

definitely put one in scissor hands though if you have any spare space. it would make all the difference in the world Smile (youd have to go back to in bot mixing though)

Post Sat Jan 31, 2009 8:09 pm 
 View user's profile Send private message Send e-mail Visit poster's website MSN Messenger
Nick
Experienced Roboteer


Joined: 16 Jun 2004
Posts: 11802
Location: Sydney, NSW


 Reply with quote  

I am thinking more about using a gyro in the flame-thrower bot - I can mount it on-axis.

Post Sat Jan 31, 2009 8:39 pm 
 View user's profile Send private message
shreddy



Joined: 09 Jan 2009
Posts: 518
Location: Wantirna, Melbourne


 Reply with quote  

how can a gyro be wired up with a sabretooth?

how much did you get your gyros for?

this one sems alright:
http://www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=6754&Product_Name=MKS_191_Headlock_Gyro
_________________
http://au.youtube.com/user/crustydemonsully

The day I stop giving 100%, is the day I stop competing

Post Mon Jul 06, 2009 9:09 pm 
 View user's profile Send private message Send e-mail MSN Messenger
Glen
Experienced Roboteer


Joined: 16 Jun 2004
Posts: 9481
Location: Where you least expect


 Reply with quote  

the gyro just goes in line with the steering channel between the radio and the sabretooth. youll have to use the sabretooths mixing. wont work if you mix in the radio.

i got my first gyro for nearly $300 but now you can buy the genuine futaba gy401's for $99 on ebay
_________________
www.demon50s.com - Minimoto parts
http://www.youtube.com/user/HyzerGlen - Videoooozzz

Post Mon Jul 06, 2009 9:13 pm 
 View user's profile Send private message Send e-mail Visit poster's website MSN Messenger
Knightrous
Site Admin


Joined: 15 Jun 2004
Posts: 8511
Location: NSW


 Reply with quote  

I know SFA about gyro, but I'm looking at experimenting with one in my next version of the melty brain. I'm in need of a head locking unit, but have no idea what's good, bad or are they all the same. So far I'm just looking at hobbycity since they are cheap Razz

MKS 191 Headlock Gyro
Telebee Head Lock & Standard Gyro (Digital/Analog)
Hobby King 401B AVCS Digital Head Lock Gyro
MKS 293 Headlock Gyro
_________________
https://www.halfdonethings.com/

Post Mon Nov 16, 2009 4:56 pm 
 View user's profile Send private message
shreddy



Joined: 09 Jan 2009
Posts: 518
Location: Wantirna, Melbourne


 Reply with quote  

hey i just ordered the mks 292 headlock gyro so wen i get that ill be sure to update you on it. it seemed like the best balance for price and options i rekon.
_________________
http://au.youtube.com/user/crustydemonsully

The day I stop giving 100%, is the day I stop competing

Post Mon Nov 16, 2009 11:25 pm 
 View user's profile Send private message Send e-mail MSN Messenger
  Display posts from previous:      

Forum Jump:
Jump to:  

Post new topic   Reply to topic
Page 1 of 2

Goto page 1, 2  Next

Forum Rules:
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum

 

Last Thread | Next Thread  >
Powered by phpBB: © 2001 phpBB Group
millenniumFalcon Template By Vereor.