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Autonomous headlamp design enquiry

F

Floyd

New member
Hi all,

I am an electrical engineering student currently undertaking a third year engineering design course. The project I am designing is an autonomous caving/mining headlight, detecting the environment?s ambient light to accordingly adjust the output light intensity and frequency. This will allow for hands-free operation, with the goals of saving power, increasing safety and convenience, as well as a more accurate colour reproduction of the dark environment. Some of the other features considered are the control characteristics of the light, type of light, weight distribution of the circuitry and a disable function to allow manual control of the light

At this stage I am trying to gather as much information as I can for the design. So far I am planning to use ~3 CREE XM-L/2 LEDs (possibly with multicolour LEDs), and simple optics with basic LDRs for light sensing. For the batteries, I will probably use 18650s or AAs, and a microcontroller to handle the logic of the dimming and colour variation. I am wondering if these are good choices; any feedback or ideas would be of great assistance. 

Cheers
Floyd
 
mrdetail

mrdetail

Member
Another small idea, as this a uni project and so maybe can be a little more adventurous in your features, low power radio data exchange between lights. Could allow some interesting features. This could also include a radio beacon for search and rescue.
 
F

Floyd

New member
As this is a design task, I am more so focusing on the innovative aspects which is the autonomous light dimming as well as the user defined colour reproduction. Petzl has a reactive lighting headlamp which uses a proximity sensor to flood the LEDs in open areas and narrow the beam for reading or close observing of cave features. I will have 3 LEDs in a row (spaced out) covering ~120 degrees.

Due to the 10 week deadline (+full time uni student), i'm unfortunately limited as to what i can incorporate into the headlamp. If time permits, i might still add it into my design but as a manual feature.
 
Addy

Addy

Member
Hi Floyd...
It may be blindingly (sorry) obvious but caves and mines are generally 100% dark so a light sensor may be of little practical use.
In caving, the only light generally encountered is from other cavers' lights and it would be unfortunate to have one's lamp dimmed by the approach of other cavers...
The Cree LEDs and 18650 Li-Ions are probably good choices for the lamp.

Cheers,
Graham.
 
martinm

martinm

New member
Addy said:
Hi Floyd...
It may be blindingly (sorry) obvious but caves and mines are generally 100% dark so a light sensor may be of little practical use.
Click to expand...

If you have a light, the cave or mine isn't then 100% dark! The light sensor can detect how much light is reflected off the surrounding walls, etc. I think this would be very useful.
 
T

topcat

Active member
I think it is a solution in search of a problem.

In any case, Petzl and Silva already have lamps that do this reactive thing.  There is a reason why you
don't see them caving.

I want to control my light.  I'd be extremely pissed off with a light that did its own thing.
 
martinm

martinm

New member
topcat said:
In any case, Petzl and Silva already have lamps that do this reactive thing.  There is a reason why you
don't see them caving.

I want to control my light.  I'd be extremely pissed off with a light that did its own thing.
Click to expand...

Have you any models details of the  Petzl and Silva lamps?

I think it would be very useful. Going from a big walking passage into a crawly bit the light would dim automatically and save power. If other cavers approached you, it would dim so as not to blind them! I have read many comments on here about cavers lights being too bright.

One Caveat though:- it would need a manual override.
 
D

dmcfarlane

New member
Actually, I HAVE seen reactive lights used for caving. My colleague has been using the Petzl Nao in the caves of Borneo, and likes it.  I haven't worn it myself, but nor have I seen any problems with it.

DM
 
martinm

martinm

New member
dmcfarlane said:
Actually, I HAVE seen reactive lights used for caving. My colleague has been using the Petzl Nao in the caves of Borneo, and likes it.  I haven't worn it myself, but nor have I seen any problems with it.

DM
Click to expand...

Thanx for that, just watched the promo video for the Nao and it looks fantastic, which does unfortunately beg the question:- What is Floyd proposing that is better and/or different to the Nao? Floyd?
 
Antwan

Antwan

Member
Hi Mel, what Addy is getting at is the use of a LDR (light dependant resister) instead of a proximity sensor. The Nao detects how 'closed in' your surroundings are to do the dimming, if it measured the amount of light getting reflected back when someone else looked at you it would turn your light off.
 
Rob

Rob

Well-known member
topcat said:
I think it is a solution in search of a problem.

In any case, Petzl and Silva already have lamps that do this reactive thing.  There is a reason why you
don't see them caving....
Click to expand...

Because they are quite new technologies and haven't yet been ruggedised?

Many inventions and developments are improvements without the need of a specific "problem". I think this should have very good application to caving and so think it will become popular among many cavers, in time. I do think the devil will be in the detail, setting the max and mins "right", and having the "right" amount of control, a process that will take time.

Floyd, my advice is that whatever you make probably won't be rugged enough for cavers, so just don't worry about that side of things. Get the electronics sorted, other people can ruggedise it in time.
 
caving_fox

caving_fox

Active member
How much improvement in lifetime running are we talking about here?

Current lights are easily getting 20+hours runtime at high (although not max) intensity. I'm not sure 1 % increase in duration is worthwhile. Or even 10% as few people actually run out of battery life on trips these days, conversely it still won't be enough for expedition work. It would enable a brighter beam to be used for longer, but that's defeating the object?
 
F

Floyd

New member
Thanks for all the replies guys, all have been extremely helpful.

I only found the Petzl Nao product after a few companies mentioned it which was unfortunately after my design proposal was accepted.

The only adjustment that I can think of to Petzl's product (whether its feasible or not I'm hoping you guys can help) is that Petzl purely measures the reflective light of its own beam which gives a small sensing angle, disregarding light from the surroundings potentially from other cavers and there lights. Also there product comes with a $200 price tag (my market research on this product has everyone saying the price tag is its major flaw) for a Max 355 Lumens. If the use of LDR's proves to be sensitive enough, I believe mine would be much more cost affective.

Also talking to a caving instructor in New Zealand, he said that he took a flame into a cave once and gave a realistic 3D feel to the environment. That's why I have a manual colour adjustment for the user.
Has anyone ever used a colour other than white light that gave a much more realistic visual of the environment?
 
Bottlebank

Bottlebank

New member
Floyd said:
Thanks for all the replies guys, all have been extremely helpful.

I only found the Petzl Nao product after a few companies mentioned it which was unfortunately after my design proposal was accepted.

The only adjustment that I can think of to Petzl's product (whether its feasible or not I'm hoping you guys can help) is that Petzl purely measures the reflective light of its own beam which gives a small sensing angle, disregarding light from the surroundings potentially from other cavers and there lights. Also there product comes with a $200 price tag (my market research on this product has everyone saying the price tag is its major flaw) for a Max 355 Lumens. If the use of LDR's proves to be sensitive enough, I believe mine would be much more cost affective.

Also talking to a caving instructor in New Zealand, he said that he took a flame into a cave once and gave a realistic 3D feel to the environment. That's why I have a manual colour adjustment for the user.
Has anyone ever used a colour other than white light that gave a much more realistic visual of the environment?
Click to expand...

You've got me missing my carbide lamp. I might dig it out, hopefully Bernies still sell the stuff.

Quick answer is yes, carbide gave a great feel to a cave, (given your age you may need to google "carbide lamp" - no offence intended). Older electric lamps with filament bulbs likewise. A much more natural feel. Not sure how a manual colour adjustment would work but it would be interesting to try.
 
Rob

Rob

Well-known member
Floyd said:
...The only adjustment that I can think of to Petzl's product (whether its feasible or not I'm hoping you guys can help) is that Petzl purely measures the reflective light of its own beam which gives a small sensing angle, disregarding light from the surroundings potentially from other cavers and there lights....
Click to expand...
I think this is the main success of the Nao product.

Only "improvement" i can think of is a directional system with multiple focused LDR's and light sources, all working independently on a grid system. So the passage ahead is thrown more light than the floor, which needs less as it's much closer. Good luck designing that!
 
Mark Wright

Mark Wright

Active member
I have a Petzl Nao and to be honest I find the constant changing of light levels to be really annoying. If you were doing a delicate climb and moved your head rapidly, rather than increasing safety I think it would more likely cause an accident.

When you consider the cost of a new Scurion I don't think it is the ?135.00 UK RRP that will put people off. What is good about the Nao is the light levels. We are often a bit too concerned with the Lumens. When we tested the Nao in the Berger a few years ago, before it went into full production, we found its maximum 355L produced the same light levels as a 750L Scurion!!

As for wanting a feel for the old time carbide lamp, Scurion already offer this facility with their lamps, or at least they did the last time I looked.

Mark Wright
 
bograt

bograt

Active member
Rob said:
Floyd said:
...The only adjustment that I can think of to Petzl's product (whether its feasible or not I'm hoping you guys can help) is that Petzl purely measures the reflective light of its own beam which gives a small sensing angle, disregarding light from the surroundings potentially from other cavers and there lights....
Click to expand...
I think this is the main success of the Nao product.

Only "improvement" i can think of is a directional system with multiple focused LDR's and light sources, all working independently on a grid system. So the passage ahead is thrown more light than the floor, which needs less as it's much closer. Good luck designing that!
Click to expand...

And all this on a helmet mounted light!, I foresee neck problems carrying that weight :blink: :blink:
 
Spike

Spike

New member
Floyd said:
Also talking to a caving instructor in New Zealand, he said that he took a flame into a cave once and gave a realistic 3D feel to the environment. That's why I have a manual colour adjustment for the user.
Has anyone ever used a colour other than white light that gave a much more realistic visual of the environment?
Click to expand...

Could that be more to do with the flickering and lateral movement of a candle flame changing the shadows cast to enhance the 3d effect - if you can "enhance" the 3d effect of real life...

Perhaps that's why BDI shadows are less "treacherous" than those of electric torches?
 
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