Failsafes

Please post all questions and answers in here. This way people can easily see if someone else has the same problem.

Moderators: administrator, BeligerAnt, petec

Andrew_Hibberd
Posts: 1295
Joined: Tue Jan 20, 2004 12:00 am
Location: London
Contact:

Failsafes

Post by Andrew_Hibberd » Sat Oct 29, 2005 3:52 pm

Just started a discusion after reading the post by simon in the comitee page. The lightest onei have found is 10g from technobots.

It is interesting as more people are going to be using the sozbots board and barello ones.

Anyone know if there are any plans out there?
TEAM GEEK!

User avatar
Simon Windisch
Posts: 2194
Joined: Tue Apr 15, 2003 12:00 am
Location: Reading
Contact:

Post by Simon Windisch » Sat Oct 29, 2005 5:37 pm

Andrew,

I'm feeling lazy, but do these failsafes work for all channels, or will you need to get one for each wheel, and one for a weapon.

Simon

User avatar
BeligerAnt
Posts: 2464
Joined: Wed May 15, 2002 12:00 am
Location: Brighton
Contact:

Post by BeligerAnt » Sat Oct 29, 2005 6:47 pm

Has anyone queried the lack of failsafe with Sozbots? I just wonder why they have apparantly removed a safety feature?

As I understand it the failsafe is usually implemented in software in the microcontroller that provides the speed control function. It's not even difficult software!

I would guess that an aftermarket failsafe would be for a single channel. A real pain having to add 30g in failsafes :cry: There must be a better way...

(Sorry no solutions here)
Gary, Team BeligerAnt

User avatar
Simon Windisch
Posts: 2194
Joined: Tue Apr 15, 2003 12:00 am
Location: Reading
Contact:

Post by Simon Windisch » Sat Oct 29, 2005 7:21 pm

I contacted Barello, who have the same problem, but they never replied.

I believe that Peter Waller had a point of view regarding this. To quote him (and apologies if I get this wrong) There's a difference between turning the transmitter off and seeing the robot stop moving during scrutineering, and the effects of having multiple similar frequencies transmitting at the same time that the transmitter is turned off, i.e during combat.

Simon

josh
Posts: 1115
Joined: Thu Apr 28, 2005 6:56 pm
Location: Uxbridge, London
Contact:

Post by josh » Sun Oct 30, 2005 6:58 am

well do i ave to buy a seperate failsafe if im jst usin servos then?!!!

Remote-Controlled Dave
Posts: 3716
Joined: Sun Apr 03, 2005 5:30 pm
Location: Antrim, Northern Ireland
Contact:

Post by Remote-Controlled Dave » Sun Oct 30, 2005 1:32 pm

Some of my bots twitch a little when the transmitter is turned off before the bot itself, but I think its because of static and devices round the uni in such a small space. None of them move enough to present a problem I hope, I'll just make sure I turn them off before the transmitter.
Die Gracefully Robotics
Winner - AWS 39

User avatar
peterwaller
Posts: 3709
Joined: Fri Feb 15, 2002 12:00 am
Location: Aylesbury Bucks
Contact:

Post by peterwaller » Sun Oct 30, 2005 1:51 pm

That is about it Simon my argumants are this.
There is no antweight WS rule about a failsafe as far as I can remember, correct me if I am wrong, it just crept in at some events.
Secondly a fail safe can usually only detect pulses outside the normal range of 1-2 ms which will not filter out interfance from other transmitters.
I believe that where possible failsafes are a good thing but if they are not 100% reliable we should not depend on them. I think we should always handle our Robots as though the drive or weapon will go off at any time. The most important thing is always turn on the Tx before the Rx and never turn off Tx before the Rx. I have just designed a new drive speed controller which has software failsafe but the last thing you want is the robot shutting down every time there is a little interference because at the range we work that is happening all the time. I have tested them on their own but it will be interesting to see what happens in the presence of half a dozen other transmitters. Must put soapbox away now.
????????????????????????????????????????????????????????????
Just gone and looked at the rules and it does say that the Robot must stop when the Tx is turned off either I am going senile or I missed that one being introduced. I would be suprised if many robots would remain still in the presence of other transmitters on adjacent channels when its Tx is switched off.

EpicentrE
Posts: 1079
Joined: Mon Jun 09, 2003 12:00 am
Location: Coventry
Contact:

Post by EpicentrE » Sun Oct 30, 2005 5:12 pm

While I obviously agree that there are ants capable of mangling any part or someone whos careless enough to put parts of there body into their weaponry, I don't think we need to worry about failsafes as much as it seems everyone is suggesting. I think with just a bit of care you could easily disable and safely turn off/unplug any of the current ants without causing any danger to yourself. Maybe an idea would be something like wooden blocks on the end of poles, if a spinner did get out of control, you could simply shove it into the corner with the blocks, jam the disk, and then safely pick it up and switch it off
Scott Fyfe-Jamieson, Captain of Epic Robotics. Champion of AWS38/41/42.
http://www.epicrobotics.co.uk

User avatar
Simon Windisch
Posts: 2194
Joined: Tue Apr 15, 2003 12:00 am
Location: Reading
Contact:

Post by Simon Windisch » Sun Oct 30, 2005 6:51 pm

Just to confirm, rule 2.u in the 3.1 rules states "When the control transmitter is switched off, out-of-range or subject to interference the robot must cease all motion."

I remember this being checked quite strictly at the Featherweight competition back in 2003 and again at the last AWS in Aylesbury, although not at any other time, when the only things checked were weight and size.

Josh, if you're using servos plugged into a receiver then this should not affect you, it's only really for peple using speed controllers.

Simon

Adam Hargreaves
Posts: 223
Joined: Sat Apr 30, 2005 9:25 am
Location: Loughborough
Contact:

Post by Adam Hargreaves » Sun Oct 30, 2005 8:11 pm

i tend to just grab my disc any old fashion (it's not that powerful). it has a mind of it's own so is unlikely to see an AWS (using a servo board with a slightly better motor (which has capacitors on))

I lost the top 1/3 of my Tx antenna, could this be why I'm prone to interference these days? (i personally suspect it's my HiTec feather, my old micro never used to get this much interference)
Team 'In Theory'

Post Reply