Let's Make Robots!

"Halo" Xmas bauble edition.....

Projects a laser generated "Halo" on the floor .... as an object detect system

I present "Halo"  ..... my latest Laser Robot

It been almost a year now that i have had the idea to cast some form of "Halo" around a robot and detect the reflected signal.

               Then after playing with some motor driven angled mirrors and lasers .... the idea came, narrow down the resulting Laser circle and beam it around the Robot........

               I placed a Wii-Camera above the whole contraption and was able to capture the laser circle.....YAY.

The Wii-Camera is able to track the Laser at a good speed.

The system is still in experimental stage .... i just need some Plexy glass do-dadds (any ideas from the Laser cutting Gurus out there?) to make it "Round and Sound" ie to mount the Laser/motor/Wii to the robot.

When the laser beam is broken by an object or a "cliff" then it possible to detect a break in the circle picked up by the Wii-Camera.

This is just the start of a whole new concept for me..... still much processing to deal with.

Many robots rely on a sharp or ultrasonic sonar based systems or northsoutheastwest IR leds which are err i stick my head out here Low resolution.......the laser "Halo" system by my current ballpark calculation provides a 360° sweep circa 1024 points.

5mw Red laser works best.......(100mw Green - works .... Ultra-Violet laser - nada).

BTW ..... the tracked robot base does in fact work ...... just a question of squeezing the Wii-camera into the on board RBBB propeller system.

Update 4/11/11 :-

Just found out that pulsing the laser on and off gives a better environment for the wii-camera........

...... the wii camera works best when it can see single spots of light........pulsing the laser on and off provides this.....

Gives an interesting optical effect and shows how you can adjust the resolution by software.

It also speeds up the sampling  time

Low resolution .......

Medium resolution ........

UPDATE 5/11/11 :-

Now it turns out that a Red Xmas bauble can reduce the height of the laser pole YAY.

laser Circle still projected onto floor from above .... then Wii-Camera mounted on robot looking up at a Xmas Bauble.

The speed of the laser circle should be kept low......the wii camera can only track well at low speeds......

The Xmas bauble acts like a mirror / wide angle lens (its red colour helps to filter out none red colours :-) and picks up the relected laser ring off the floor.

Resulting image processed by the Propeller is :-

Yes we have 360° detect possibilities.

I am pleased with the result .... i have reduced the resolution by a factor of 5 for display purposes ....so plenty of spare (in my pocket).

URGENT :- Any ideas how i can adjust the size/angle of the laser ring (ie adjustable angle of laser mirror do-dadd) ?

UPDATE 8/11/11 :- adjustable mirror ..... made and ready for experimentation...See video....

        Tin Head pointed out that i could use a screw on the end of a servo, to push the mirror ....neat idea..... giving finer control.

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Update 5/11/11........ latest video explains all.....

Radar for Santa !

if you could mount it in a clear tube ,,


I just dawned on me that by pulsing the laser i can speed up the sample times and gain control over the resolution.

Wii-mote seems to prefer spots of light as opposed to a continous trail of light.......

.... simple "mod" and optically a very pleasing effect .......pictures above.....

Cool idea! Maybe you don't even need a laser to do this. Any light that form a circle around the robot can do the same result isn't it? A mirror dish or metal dish to reflect the light below should do this too? Anyway, it's a really really good idea to use the light this way. Brilliant!

Unfortunately the wii camera can only pick out the 4 brightest spots of light, so a continuous ring of light would not work (it would see it as one big spot).....unless it would have a rotating type disk with a gap that rotated a shadow onto the floor (then you could detect the shadow .... err i think)........ you can see why i plumped for laser :-)

Very pretty.

Can you make a rotating oval ?    If it rotates quickly you will get that spirograph pattern (who's French name I somehow completely forget) - and then with a little more work (and some incredible magic) you could extract a depth map :)

Keep it going Gareth !

"Lissajous curve"    Grog

Easy remarkable Translation :-  Lizard-Juice  (i will test you on this at some remarkable time ;-)

Yes in the current form, depth is possible provided you keep a steep angle of the camera to the laser ....as you say if you have an "oval" shape then Depth (Cliff height) would be in grasp ..... errr a steep angle would anyways give an oval shape....

Love it!

if for nothing else, then the visuals - Total Tron! :D

Thanks Mr.Editor Guy for posting "Halo" on the LMR front page.... :-)  

......nothing escapes the "Matrix" or am i trapped in the wrong film....