How does a Laser 3-D Scanner Work

Here's a quick post about a few things I learned about laser 3-D scanners.

In the classification of 3-D scanners, laser scanners fall in to the category of 'Non-Contact Active'. There several types of scanners in this category, but the most common type used is the Laser Triangulation scanner. These are used in scanning relatively small objects with high accuracy.

How does it work? A triangulation scanner shines a laser dot to the object and uses a camera to look for the location of the laser dot. Depending of the distance from the laser emitter to the surface of the object, the dot appears at different places on the camera's field of view, as seen on the following diagram.

Operating principle of a triangulation laser scanner

Since the distance between the laser emitter and camera and the angle between them is known, using the position of the laser dot on the camera's field of view, the distance between the emitter and the surface can be calculated. Most object scanners that use this principle use a laser stripe instead of a dot to speed up the scanning process.

Triangulation with a laser stripe

Triangulation scanners have a limited range - only a few meters, but their accuracy is high - accurate to a few micrometers.

There are other types of laser scanners such as time-of-flight scanners, conoscopic holography scanners etc. If anyone's interested, I could do few articles on them too...

References
http://en.wikipedia.org/wiki/3D_scanner

Comments

Selecting the Correct Gauge Wires for your RC Models

When we are building RC models (aircrafts, multicopters etc.), something we typically overlook is what type of wires to use to distribute power in them. Usually, we try to reduce the weight of the model, so we tend to go with smaller wires. But, we cant expect to put in small circuit-wires and have them handle the amount of power needed. If you look at the wires that comes in the output leads of a Li-Po, or the wires that comes on a standard XT Jack, you'll notice that they're quite huge. Large gauge wires on a Li-Po and XT connectors These need to be huge to handle the amount of amperage that goes through them. So, we should also consider the amperage, and the length of wire needed when selecting the size (gauge) of the wires.

Make Your Own Jupmer Wires for Electronic Breadboard

Note: After starting the 'Tips and Tricks' section I wanted to do my own 'tutorial'. So, here's my first attempt of it. Hope you all find this useful, and sorry about the low quality of the photographs, my camera is just a 2MP. If you, like me, like to experiment with electronics, then you'd probably use an electronic breadboard (also known as protoboard or project-board). These allow you to construct and test circuits without the need to permanently soldering the components. The problem with these is that you have to use wires to connect the components across the bus lines. We normally use single core circuit wires for this purpose, but they tend to bend, break and get stuck in the breadboard when used repeatedly. This may cause short circuiting the bus lines and could be the failure of your circuit. A better option would be to buy a 'Breadboard Jumper Wire' kit, such as this. A Breadboard Jumper Wire Kit These have sets of wire of differ

What do the prop size numbers mean?

Have you been trying to shop for propellers - either online or at a hobby shop - and got confused of the numbering used to denote the size of the propellers? You see things like " 10 x 4.5 CW ", or " 8055 CCW ". What do these numbers mean? A 8 x 4.5 CW and CCW Propeller Set It's actually quite simple once you figure it out. The first number denotes the diameter of the prop (length from tip-to-tip). The second number denotes the pitch of the prop. Here, the pitch is denoted as a length, not a angle. Let's see how that works.

Code 42

Search This Blog