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Extra functionality of a PLB?? (student research)

PostPosted: Fri Nov 15, 2013 12:28 pm
by joespicerack
Good morning,

I’m looking for a few opinions here to help with research for a project I’m currently doing. I am an industrial Design student from Loughborough University- the idea for the project is to make a Personal Locator beacon which can self-activate when the user becomes incapable of activating it themselves.

Although I am a keen climber and mountaineer, I haven’t ever been in a situation which I feel would warrant carrying a PLB, so hopefully I can get some insights from some of you with more experience (any opinions are welcome!).

I’m looking into functionality that could be added to the device to increase the physical interaction with it. Being an automatic PLB (albeit with manual controls as well) I don’t really have any design requirements for the unit- it could just be a box with a button on.

Any opinions on what would be interesting/vital/helpful to add to the device are appreciated.

what would YOU find useful?

(Note: These extras can be run off a separate power source from the main battery)

Any input is greatly appreciated,

cheers,

Joe

(post slightly edited!)

Re: Extra functionality of a PLB?? (student research)

PostPosted: Fri Nov 15, 2013 5:10 pm
by Buz Groshong
One thought would be to have unit in a carrier and separation from the carrier would activate it after a reasonable delay. If it accidently falls out of the carrier and the user didn't fall we would want to give them a chance to override the automatic activation. It would also be useful to have a cord connecting the unit to the carrier so that it could only be dropped so far.

Another thought could be an orientation activated device (mercury switch). As long as it is vertical it doesn't activate but being horizontal for a reasonable amount of time would activate it (if you want to lie down or lay the device down, you need to turn it off). Also, going from vertical to horizontal an number of times within a certain time period (tumbling motion) would activate it.

Re: Extra functionality of a PLB?? (student research)

PostPosted: Fri Nov 15, 2013 5:10 pm
by MoapaPk
If you make it too easy to activate, you risk unintended activation. Seems like the most useful device would be a clip/lanyard for your shirt/packstrap.

Re: Extra functionality of a PLB?? (student research)

PostPosted: Fri Nov 15, 2013 6:32 pm
by Buz Groshong
All you need to minimize unintended activation is a short time delay that allows the user to override the automatic function.

Re: Extra functionality of a PLB?? (student research)

PostPosted: Fri Nov 15, 2013 7:43 pm
by MoapaPk
Buz Groshong wrote:All you need to minimize unintended activation is a short time delay that allows the user to override the automatic function.


Maybe also have a beep-beep-beep when pre-activated, so a person will know.

Re: Extra functionality of a PLB?? (student research)

PostPosted: Sun Nov 17, 2013 4:17 pm
by nartreb
I’m looking into functionality that could be added to the device to increase the physical interaction with it.


Huh? WHY?

If it's a saftey device, it needs to be dirt simple. Set and Forget. The *last* thing you want is users needing to interact frequently with the device. There needs to be an instant, idiot-proof way to see/hear the current state (battery OK? Device turned on? Device about to begin sending unless you press the big Cancel button? Device currently sending?), an easy way to abort unintended activation (preferably with an explict "cancel that" message if an SOS has already been sent), and that's it. Note: beware of fancy display hardware. The state readout must not drain the battery, must be visible in sunlight, and must work in extreme cold. Keep it simple! Also, make sure the Cancel Alert button looks and feels very different from the Send Help Now button :)
Both the Send Help and Cancel Alert features need some physical safeguard that will prevent accidental button-presses while in a backpack, without causing delay or frustration when the user needs to use the features with frostbitten fingers.

Hm, there's a good usability study: have subjects put on heavy mittens and fogged goggles, and see if they can still use the device.

I'm having a hard time thinking of extra features that would make any sense being added to an inactive radio transmitter. Extra features just mean
- more complicated interface (increased chance of user error, e.g. unintended PLB activation)
- more complicated design (increased chance of design error, e.g. software bugs)
- compromising either battery life (if added feature uses same battery) or weight (if separate battery)

Re: Extra functionality of a PLB?? (student research)

PostPosted: Fri Nov 29, 2013 12:19 am
by joespicerack
Apologies for the delay in replying, and many thanks for all of the suggestions and input.

Buz, a delay for deactivation will of course be a vital part of the design. If a signal went out every time it was activated it would cause chaos!
Unintended activation would not be a problem when you have this window to deactivate it, provided it wasn't going off all the time and annoying the user. If left with the warning activated, it would send out the distress signal after a certain time-period.

Nartreb, I completely agree. I think it should have the functions it needs and nothing else. Adding complexity just adds to the likelihood of someone using it when they might not necessarily need to, and makes for more to go wrong.
However, I need something to give the product a criteria to meet for it's aesthetic direction- my tutor feels strongly about this and it will affect my overall mark. As it is, a PLB doesn't really have any requirements other than "not bee too big or heavy". There is nothing in particular to drive the form of the product. I was considering a basic navigation system that could help you backtrack a "breadcrumb" trail (created from periodic GPS logging) for if you become lost, but something to only be used when you really need it.
"Fancy display" hardware is being steered well clear of- touch screens etc have their place, and this isn't it. The navigation system idea would use a simple lighting system to point directions (eg LED compass type dial).
But there was lots of useful info there, thankyou.

As I said I agree with extra features. But if an innovative opportunity arises that could genuinely bring benefit to the product then it will also bring benefit to my grade!

I've spoken to a friend in mountain rescue and a few other rescuers, and they feel the same- but mainly to keep people from using it unless it is an emergency rather than for more things to go wrong with.

Thanks for the input, feel free to add.

Cheers

Joe

Re: Extra functionality of a PLB?? (student research)

PostPosted: Fri Nov 29, 2013 10:48 pm
by Andrew Rankine
Here is one idea I can think of, currently used by train operators in many places. The operator has to press a buzzer intermittently while operating the train, and failing to press the buzzer causes the train to stop. This is to stop runaway trains due to incapacitated operators.

If you put a 'dead man's switch' on the PLB, so it has to be pressed a certain number of times per day (1, 2, 3...could be set on user preference) and at that time an alarm sounds to alert the user to turn off the alarm, the user presses the button (after 5 minutes or so the signal would be sent) and stops the alarm. So if one is incapacitated and cannot turn off the alarm, the signal will be sent.

Re: Extra functionality of a PLB?? (student research)

PostPosted: Mon Dec 02, 2013 3:56 am
by nartreb
a PLB doesn't really have any requirements other than "not bee too big or heavy". There is nothing in particular to drive the form of the product.


I don't know, this could be your opportunity right there. Let's think about where when and how the user needs to interact with the thing. Do users want it:
-way down in the bottom of a backpack?
-an accessible pocket on the pack? Clipped to the pack?
-in a pocket on their person?
-strapped to their person?

Answers depend how big & heavy the thing is, how often users have to interact with it (eg. hit the deadman's switch) and where that happens (whether they can/will schedule it for meal breaks, rest breaks, while on the move, while in camp). Depending on your thinking, you might look for a shape that's adapted for particular uses (long and thin for the side of a pack? compact and cubic for pack interior? curved and comfortable for pants pockets? built-in hook? built-in strap? Remote (wired or wireless?) dead-man's switch that clips to a shoulder strap (think Camelbak)?

Re: Extra functionality of a PLB?? (student research)

PostPosted: Wed Dec 04, 2013 8:17 am
by joespicerack
A requirement for it will of course for be to be easily accessible, so that they can disable the alarm if it goes off. I need to decide on a position which balances ease of use with being able to reach it easily, yet not have it too exposed so that it could be lost (eg torn off) easily. I've been figuring out which internal parts I will require so that I can get a size estimate, so tomorrow I should be good to do some testing to see where people would find it best to attach. The aim is that they interact with it either when the alarm sounds (to disable it if they are OK), or when they need to trigger the beacon themselves.

Adding in a periodic alarm (say 4 times a day?) is a good idea, although would add quite a bit of complexity to the programming (eg being able to adjust what times it goes off, considering different time zones. Being a BA student the programming is the bit frightening me!). Although I suppose it could be set to trigger every few hours only whilst the automatic function is enabled.

Thanks for the input nartreb, it is really appreciated.

Re: Extra functionality of a PLB?? (student research)

PostPosted: Thu Dec 12, 2013 8:23 pm
by philoparts
Take a look at the PASS system on a firefighters SCBA. Designed specifically for alerting prolonged inactivity, beeps a warning to the user that it is about to activate at full volume. It can be reset either by pressing a button or movement. That's why on fire scenes or training fires you see firefighters always moving around, if not, the alarm will activate.
[youtube]http://www.youtube.com/watch?v=8SuWeVAnObA[/youtube]