Power/failsafe LED

There seems to be a problem .As several Dutch competitors dont get the whole idea about the power on LED. Also, carefull reading of the rules gives a few other questions.

Purely in the rules we have this.
4.3. In addition to the main power light (See. Batteries and Power no. 6.8.) showing the main power is activated. It should also indicate if the robot is in €œfailsafe€, €œoff€ or €œzero€ position.


On the FRA mainpage we get this rule.

As off 1st January 2004 all middleweight, heavyweight and superheavyweight robots running at FRA events will be required to be fitted with an exterior power light as a clear visual indication of whether the robot is in a powered state (i.e the removable link is in and the robot is active)

Now, what is realy needed? And how and in what colors.
I can see some confusion brewing. If Team A uses a red led to indicate Link in and team uses B a red light to indicate failsafe active on channel 1
Also, all our channels are failsafed(except for some who failsafe 1 complete shut down idea)Do each need a failsafed light?

Lots of questions needing to get an answser

on our system i cant see how we are suposed to put in a failsafe light. All our failsafes are built into the system, therefore no way of connecting any inicators into the system.

No problems in fitting a power LED, the failsafe one is the problem. I cant really see the point in the failsafe/zero led, as if its powered up, it has the same potential no matter what state its in. I personally feel safer when its under TX control rather then failsafe (but thats just me!).

Maybe we could see an example of the fitted system.

I have 2 flashing red leds when power is on so cant see any reason for the led to tell the power is off if no lights are lit then power is of
i always disconect the battery when in the pits so there would be no power for any lights
or have i got it wrong again :sad:

Mario is right this is going to cause confusion. When my powertrac switches failsafe they illuminate no LED, when on they are green/red depending on fire state... the quasar mixer flashes red LEDs in its normal state, and has steady LEDs in failsafe....the old RF1 units do it the opposite way around....so thats 3 different failsafe indicators in one robot.
Im not sure of the benefit of failsafe indicators, If the power is on I cant see anyone approaching a robot with anything less than caution is safe whether your lights are flashing or not.
I think the power light is a good idea, as it tells you whether the link is in, but even this only tells you when its in, as a lack of lights could mean the link is out, OR the indicators have packed up.

Thanks for the feedback guys.

The failsafe indicator has been discussed fairly heavily since the original release of the rules and its been concluded that we should remove this from required status and place it into advisory.
Theres good reason to have them on board as they are a further visual indicator of the state of the robot both for arena crew and roboteers, but as has been mentioned here, there are issues on the technical side, which make them very hard to implement for some.
There is a revision of the FRA rules due out early 2004.. nothing serious.. but a few re-wordings etc will hopefully clarify the points that have caused confusion/worry so far. As the failsafe light is planned to be changed there wont be any requirement for it at any FRA events run in the interim.

So to clarify:

a. The power light is required.. it doesnt matter what colour it is as long as its easily visible.

b. The failsafe light is advisory.. and dito with the colours.

Hope this helps.

Regards
Samuel Jones
FRA Safety Committee

Translated and posted on the Dutch forum.

My advice.
for the Power on(or Link In light) a red warning light(LED or otherwise)
A green light(or LED) for the failsafe function.
For the power on I suggest non blinking. The failsafe doesnt matter, as it blinks or stays on, there is a problem. An occasional glitch is possible. But not as if the meaning can be misunderstood.

Now, the light/LEDs are an indication, not a truth. So even when a robot in the arena shows no lights stay carefull.

As a couple of posts above say:

a lack of lights could mean the link is out, OR the indicators have packed up.

and


So even when a robot in the arena shows no lights stay carefull.

If you have put your link in your robot you should treat it as live at all times, regardless of what indicator lights say. Given that, it seems to me that a power light is as likely to cause accidents as to prevent them because it could give a false sense of security in some cases. The best indicator of a robots status is the link itself - if it is in your pocket the machine is safe, if it is in the machine, the machine is not safe.

We think its a good idea for the power lights and had them fitted before series 7 along with weapon active LEDs and disagree with John. Ive seen robots with the link removed that have still been active due to wiring incorrect and if power lights across each speed controller light up then this can be spotted sooner.

One possible example of this is if you use a speed controller with large capacitors in it there is suffeceint power in them to activate a weapon relay long after the link is removed and the lights would show this.

The lights would eventually drain the capacitors too, so it even helps to solve the problem.

While looking for a nice featherweight motor i came across this:

http://www.heliproz.com/gem2000.htmlhttp://www.heliproz.com/gem2000.html

maybe something to take a look at?

i thought there would be a unit out there. The dual one would be great for invertables.

according to the rules, what exactly would this system need to do?

i know they are advisory, but while im busy making splinter FRA compliant, i want to do this at the same time.

My interpretation is, the power light is on whenever power is availble to a component or system with a physical actuator, such as a drive motor or a pnuematic valve. For example, Cayenne has the removeable links between all the power systems and battery negative, so I would connect the power light between battery positive and the side of the link not connected to battery negative.

The failsafe light is on when no valid signal is received from a transmitter.

Is this correct?

At the last fra meeting, Kev told me the minimum requirement is a light that comes on when the bot is powered.

I would like to query the whole concept of a power-on indicator. Where can it be situated? can I simply put a light next to my link that comes on when I put my link in? seems a waste of time.

Surely with adequate pit controls over links etc this is un-neccessary.

I guess the most prudent thing would be to put it where you can always see it (or almost always). Example: Tough As Nails has one that you can always see glowing no matter if the robot is upside down or not.

I have a new decoder that may solve the POWER/FAILSAFE lights problem.
It is part of my 459 Mhz radio control ststem.
It has two LEDs, one red and one green.

Flashing Red LED means the power is on but no valid radio control signal is being received, steady red means a good signal is being received.

Flashing green means failsafes are not set, steady green means they are set.

This PIC decoder can be programmed (by me) for Futaba PCM signals or standard PPM signals, up to 12 channels.
The PPM version has built in failsafes for all channels.
The PCM version works with the Futaba 6 and 9 channel PCM transmitters.
We are working on a JR PCM compatible version.
It is part of my latest 459 Mhz radio control receiver.
email rp@bigc.moycom.co.uk

What will be the price though Roger?

Agreed your UHF systems are excellent but financially only available to teams with lots of dosh.

I have just bought a Muliplex 259mhz Tx and Rx off a model flying friend for £50...hope to have it up and running once I get a minute spare.

Good luck with all your UHF stuff

Tom

With no disrespect to Roger - I think the problem here is with definitions, rather than technology.

The term failsafes are set means nothing to a system such as mine. Fail safe is something I build into a system, not a component. I can understand this in terms of the actual unit called a failsafe but not all robots use these.

What these lights mean needs to be set by the arena operators, not by robot builders, as these are the people who will rely on these lights when its most important. I feel we need more explicit rules for these lights.

I agree with Jim, something for the FRA agenda?

I have 3 leds on gman 2 flashing red for weapons and radio on and a green for the 24v link

So here we have the problem. On WBC green means failsafes on, on GMan, green means link in...

Oh dear... well need colour codes... suggestions anyone ?

...and to make it worse, has anyone checked how many of us roboteers are colourblind? Green LED you live... red your ****ed. What about those of us that cant tell the difference?

Suggestion 1 (could be tricky):

Red (flashing or constant) = link in (required)
Yellow = weapon controller live
Blue = drive controller live
Buzzer = fault (failsafe failure, etc)

Suggestion 2 (slightly more simple):

Label your LEDs :)

The colours of the indicators are not the main problem when safety is in question.
The only thing that matters is whether the robot is safe or not.
If the power link is IN then the robot is potentially unsafe.
If it is out and the weapons disabled and locked, then it is safe.
A lit LED or other indicator proves only one thing, that the LED works and it has power to it.
It says nothing about the device controlling the LED or its logic state.

We have all seen the car, with its right indicator flashing, turning left.

The same applies to robots, what do you do when the link is in and the lights are off? or the lights are on and the link not in?, both indicate that the robot is unsafe, i.e. in just the same state as a robot with its power link in and without any indicators fitted.

Robot systems are notoriously unreliable at the best of times, even before they are damaged in battle.
Home made or home installed systems to indicate the state of the power or failsafes are just as liable to failure as the robot they are in.

I run a robot event each year here in Somerset and work to the following safety guidelines:-

1. The robot gets a technical inspection to prove it and its failsafes operate correctly when it arrives at my event.
2. It is only powered up and its weapons locks removed when it is in the arena.
3. The arena is strong enough to contain it whatever it may do. If the robot is potentially too powerful for my arena, (such as Hypnodisc), then it does not get powered up.
4.The link is taken out and its weapons made safe before it comes out of the arena.
5. All tests after repairs are done in the arena and are supervised by me or my appointed deputy.
6.At no time is a robot powered up in the pits area.
7.If a robot in the arena does not respond to its controller then it is treated with extreme caution until made safe by some one competent.

If you stick to these rules then you do not need indicators of unknown reliability.

I have no problems getting full insurance cover for my events. The insurance company accepts the above rules and my certificated competence from previous work experience.

This is not meant as any criticism of the FRA rules, I am just pointing out that safety indicators may not be reliable and dont help to make an event safer.

Yeh lets all spend so much time farting about with flashing lights that the machine ends up looking like a christmas tree and nobody knows what any of it means.

Regarding the power light.

This was introduced for several reasons:

Number one was after a near miss accident at Newark last year, where all present felt that an exterior indication of the link in status of the robot would have stopped it happening.

Number two was as a further exterior indication to arena staff as regards to the status of the robot, a sort of extra caution sign if you like.

Number three was that through sheer familiarity with the machines, a lot of us as roboteers have become increasingly careless with the way we handle them, it was felt by a lot of organisers and roboteers that this light could just be the thing that reminds us, or makes someone close to us prompt us into safe working practices with the robot, and so prevents a nasty accident.

We however are also aware that lights break, and that it shouldnt ever be considered a robot is dead just because the light is off!

As to colour, it doesnt really matter what colour the light is, as long as it comes on as soon as the link is in place and goes off as soon as the link is removed.

The failsafe light is due for a rewrite in the rules and is being moved to advisory status both because of technical difficulties in fitting for some and for the reasons of confusion that many of you have discussed above, it is currently not being enforced by any FRA events.

Hope this clarifies and keep the feedback coming guys.

Sam
FRA safety executive

Does the light have to turn off as soon as the link comes out as at present ours does not it take 5-10 seconds to go out after the link is out?

Sam, I still dont see the need for a power on light.
If the link is in then the robot is active and possibly dangerous, or some parts of it may be.

The link should only be in when the robot is in the arena.

Therefore if the robot is in the arena and its link has been put in then it is dangerous.

If the link is in and the light off then it still potentially dangerous, even more so because if the light aint working then something is damaged.

Surely we dont need a light to remind us that we put the link in 5 minutes ago when the robot was put in the arena.

If a robot stops during a fight and the light is off, then some one may falsely believe that the robot is safe when just the opposite is the true.
It is in an unknown state, which is more dangerous than when working properly.

The roboteer who disarms it should be supervised by your event technical expert.


The failsafe light is also unreliable.

Unless all the failsafe indicators are tested and approved by some agency similar to British Standards i.e. like a car MOT, and NOT damaged then they too are of questionable value.
They would have to be MOT tested again every time they MAY have been damaged.

Such testing by an approved agency would be prohibitively expensive, and the test only valid until the robot next fights or is modified.

If the indicators are not independently tested and we just rely on the roboteer to say that they work OK then they are no more reliable than the robot.
A home built indicator is no more reliable than a home built robot.

I have developed a failsafe indicator as part of my new decoder system, it works 100% in all my tests, but I would not stake my life on it to tell me that a damaged WBC is safe.

I think that the only answer is to get all competitors at an event to sign a disclaimer that they alone are responsible for arming and disarming their robots.

An assessment of the robot builder€™s competence should be part of the technical inspection before the robot is accepted at an event.


If, as an event organiser, you are not satisfied with the robot builder€™s competence to look after any failure then dont let them take part in your event, or have someone on hand who is expert enough to make any robot safe when required.

This expert should be included by name in your insurance policy, just as named first-aiders are in employers liability insurance.

As the event organiser, and therefore the person legally responsible for everyone€™s safety, you always have the option to leave a damaged and very dangerous robot in a closed arena until it runs out of power or gas.

If it on fire it is your decision as to whether to safely extinguish it or not.

My first event of the new season and with my new power and weapons active lights i and the roaming robots crew new exactly that every thing was powerd up and ready. and i am all for it just as a warning if nothing else

Lee, you know it worked when you tested it, but would you trust it to still be indicating correctly when your robot has been damaged in the arena?
If none of the lights were still on would you think it was then safe?
Can an event organiser be sure that the indicators are correct just because you say it works correctly?
Would you trust some one elses indicator system on their robot?, I would not, and by that logic I cannot trust yours either, just on your say so.

I am not saying that yours does not work, just that it is not possible for me to know that it, or any one elses indicator system is working correctly at all times.

When the link is in, that is the only warning that you need to tell you that the robot is dangerous.

The lights are fine for you to know that every thing is powered up, but when they are not lit does not indicate that they are not powered up, that is the crucial point.

You can never trust such a fragile thing like leds and bulbs common sence as to prevale and all bots must be treated the same with great care. All my lights do is tell me that all my systems are working at the start and to be honest i ignore them at the end and disable Gman the same way as normal. And personaly i think no one should trust any kind of indication that a bot is safe and us a bit of common sence

Sam, perhaps you could (without naming names) tell us more about that near miss incident? Maybe that would help this discussion a bit. As it is I am tending to side with Roger that as described the lamp system is likely to be unreliable, and most likely to fail UNsafe!

Perhaps a better idea would be to have an LED lamp connected to the two sides of the safety-link socket. When the link is in the pins of the led are shorted, and it goes out. If the link is out, then the full 12/24/36 volts is across the LED and it lights. (To survive high voltages it would benecessary to use a suitable LED, or LED and high-value resistor, or even an array of LEDs.)

This system would be a positive robot is safe indicator. All the failure modes I can think of (led fails / becomes disconnected, battery fails, battery short, wiring failure) would cause the LED to go out, which could be assumed to be a robot is dangerous or malfunctioning indication.

If a large LED was used with a mask perforated to say SAFE, then this would be a highly positive, and as far as I can see almost fool-proof system. No SAFE sign, the robot is a threat.

The only downside I can see is that the LED might, if left in for a great many hours, drain the battery. However, no roboteer should leave a battery in the robot for that length of time, surely?

You could perhaps combine this sytem with a link is in lamp as sugested. Multiple, parallel LEDs would be most reliable, but still not idiot-proof. An additional battery in lamp would provide extra warning, but again would be a danger in itself if it failed.

Richard, the batteries in WBC are left in all season, and are charged in situ, so an indicator across the link would mean that the battery would drain.
Removing the batteries from WBC is a considerable amount of work.
With the link removed they are isolated from the system so are safe, no need to remove them unless I need to work on it.

I have no problem with robots coming to my Yeovil show with whatever indicator system the builders like to put in them.
I shall regard any lights fitted to a robot as no more than decoration, the only safety criteria for me is, if the link is in it is dangerous, if out and the weapons locked with the gas turned off it is safe.
The lights may be used by the builder for whatever purpose they like, I shall pay no heed to them from the safety point of view.

Im sorry to sound a bit mean, but: That would be a down right stupid idea. A led will need 2-20 mA, this is enough to charge a capacity in a speed controler. This in turn could, in a freak occurence, trigger a valve that will set off a pneumatic wheapon.

Off is off... 0 current, slich, nothing. Otherwize it could potentially be dangerous.

Im not sure that system will work. In order for the LED to light the power components of the robot would have to be drawing power through it. If the speed controllers are inactive (e.g. no radio signal), they may not be attempting to draw any current from the main battery. The LED would only light up when the links were out and the speed controller was actively trying to draw some current, which is not very common.

I think.

Jim, that would not work for ours with 4QDs as there is a bypass bleed resistor that charges up the capacitors to allow enough power to activate the relays when the ignition switch is on. Its reason for being there is to prevent sparks when connecing the link. Its a bad idea forget it.

Roger, Use some common sense please. The power light is there because experiance have shown that robots in the past have removed thier link and have still been active (ie the link did nothing). IF and only IF the light is fitted correctly will you see that it is still on but it would alert people to the fact that it is still active in the pits. If I see a robot with any lights on it when its in the pits I would certianly treat it with caution would you? If you power up your robot and the light does not come on then whatever the reason (Light / link fault) it should not be allowed to fight. How many people to you expect to be at Yeovil. How many were thier last year :). Dont put people off going to your events as Im sure that many wont go if the FRA dont approve your event.

Common sense would indicate that if a robot has its link fitted incorrectly, so that removing the link does not remove power from the robot, it would fail technical inspection and not be allowed to fight. The inspection at the Worthing event included running the transmitter with the receiver on and the link out.
If damage in the fight could cause the robot to fail so that it is active with the link out, it could also cause the indicator light to fail.
Roger is correct about this, the only way to know a robot is safe is to have the link out, the gas off and the weapons locked (and even then be alert).

If a machine has a link removed and is still active due to poor workmanship or malfunction, then by the same rational a light that is off could indicate that a machine is still active.

Im not against the light idea - I just dont see it makes any difference. If a machine is in the pit then the radio and link must be in the tx control except for a tec check.
If a machine is in the arena I always assume it is potentially a killer, lights or no lights ill keep well away until its on a cradle with link out gas purged and locking pins visible.

Well, we€™ve got lights on both heavyweight, and feather weight.

Last night we were repairing and testing both robots....

The feather weight wouldn€™t work, the link was in... power light off, nice n easy for us to realise it was a battery connection that was the problem.

The light shouldn€™t be used as a guarantee, but....

After a fight when robots are immobilised, and a member of my crew has to go in to make them safe, a quick visual check, tells the person which ones are definitely live and which ones are ( visually ) dead. And so which ones to go for first.

At the end of the day it is another visual warning.

I fully support them in all weights.

Jonno
http://www.roamingrobots.co.ukwww.roamingrobots.co.uk
http://www.ukinnovations.co.ukwww.ukinnovations.co.uk