Cornell University has just completed their ECE 4760 Designing with Microcontrollers Final Projects. There are lots of great projects, this 3D Laser Scanner by Ryan Dunn and Dale Taylor looks to be a flexible scanning system. Code and schematics are provided so that you can learn from their project. "Our project implements the hardware necessary for a laser triangulation 3D scanner as well as a PC user interface for controlling the scanner and acquiring data via an Ethernet connection. Our scanner facilitates 360-degree scans through the implementation of a rotating sample platform. Each position of rotation is scanned using a linear actuator to increase resolution. The basic setup consists of a laser line diode, a camera, and a sample. The distance between the camera and laser diode, d, is fixed and known. The laser line is projected onto the sample and is monitored by the camera. Using the known parameters of the camera, the angle theta between the laser, camera, and laser line on the sample can be calculated. Upon computing this angle, the distance between the laser and the sample, x, can be determined using the formula x = d*tan(theta). With a linear actuator we can map the distance x over different values of y as actuation occurs. After the scan has been completed, these points can be reconstructed in three dimensions assuming z is proportional to the height of the point in the image." |