Let's Make Robots!

"LoMoR" - Lets Orientate & Map Our Robots (Sonar Based)

"LoMoR" - Lets Orientate & Map Our Robots (Sonar Based)

 Also Blogged as Mystery Object Here

My System Uses a LCD display to Map an area which is scanned by an Ultrasonic or IR Distance_ing transducer.

The Angle of the Probe is converted from polar Coordinate to Cartesian Coords and then displayed X,Y fashion on the LCD Display.

The System works pretty well i must say, however the "Extra" echos of Ultrasonic signal can be miss-leading.

What is super cool is being able to see what the Ultrasonic or IR sensor sees - it sees a lot more than you would think, or should i say Too much more!!

I am not sure what the overshot areas on the plot are yet. (maybe i have to mount the transducers sideways).

I mounted the Ultrasonic Transducer Vertically and it gave slightly better result - the plus point is the transducer can pivot better around itself.

Basic system is so:-

  1. Arduino - LCD walkthrough
  2. GLCD based display
  3. Data Sheet for KSO108B
  4. Ultrasonic or IR Distance Transducer connected to a servo.

My code_ing works this way :-

  1. Servo scans with attached Ultrasonic or IR sensor taking distance measurments
  2. From this you have the angle of the servo with distance to object
  3. Convert the Angle of the servos Polar Coordinates to (cartesian coordinates)
  4. ie x=cos(angle)*distance, y=sin(angle)*distance
  5. then you can plot direct to the display x,y
  6. Result is a visual map of your scanned area.

Video (1)  URL :- LoMoR with URM37 Ultrasonic Sensor (Film was made by my Son, voice over by me)
Video (2)  URL :- LoMoR with Sharp GP2Y0A02YK0F Infra Red Long Range Sensor

Video (3)  URL :- LoMoR with Maxbotix LV-EZ1 - Ultrasonic Long Range Sonar

Comment viewing options

Select your preferred way to display the comments and click "Save settings" to activate your changes.

I have since mounted the Ultrasonic probe vertically and it improves the signal. (maybe this eliminates the 2cm gap between the transducers!!)

Also the ability to Turn on the Spot allows a tighter and more directional beam.... 

NB i cant work out which is the TX and Which is the RX on the module i have....

Last time I tried to feel my way around a room blindfolded using a chair I had to buy a new TV.
Awesome work Gareth. You may be getting some inaccurate readings on the edges of the DVDs because of the limited space inside your testing "ring" bouncing the sonar around. Could you try it again with 3 DVDs but remove the others surrounding it? I wonder if that wouldn`t make edge detecting more accurate.

Yes removing the surround way improves the picture.

As i am "in at the Deep End" on this - there is a lot to explore.

My idea or the picture i had in my brain of what the Ultrasonic scan would look like was shattered when i saw how easily the signal is confused by "extra" reflections comming of neighbouring objects.

Simple Finding so far are :- 

  1. Hard flat objects are an ultrasonics best friend, however tilt the surface slightly and the signal bounces.
  2. Round objects throw off big shadows, and appear larger than they actually are - from tests up to 5X at 30cms

Hey that's awesome, looking good!

It almost looks like you Drew the beginning, with your name on it, that's awesome! And you do realize we're going to have to raid your sketch folder for some code, right?:D But we'll let you keep the idea for a while before releasing it, muaha. 

The Start was drawn using Gimp (super freeware graphics proggy) and converted to Black and White.

Then basically you can throw the graphic direct onto the display.

The code is very basic - the key point is converting the Angle of the Ultrasonic into Polar Coordinates.

How did you do the video overlay at the end? Thanks!

Basically i use Edit Studio Pro to make the darkblue of the screen transparent - leaving the lightblue (data) visible -

then you overlay this onto video picture, in this case a picture of the coffee table with the dvd boxes, and hey presto two Videos combined with good clarity.

Check my other bots here where i have used "Blue Screen" - "Don Quixote the making of video shows how its done"and MechWalker to