North of Germany:
Mr. Eric Bergholz
Phone: +49 (0) 391 544 8619220
South of Germany:
Mr. Eike Thiele
Phone: +49 (0) 89 9611 8483
Laser scanners are used for the quick and complete measurement of complex geometries. It is a new technology that is increasingly replacing classical measurement methods. Applications are determined by the hardware and the physical principles of the commercially available scanning systems. In the hardware section we will describe the different instrument types and the measurement methods they are based on.
Laser scanners are non-contact measuring systems that operate on the basis of laser light. With this measuring method, a laser beam is emitted by the laser scanner sensor, reflected by the environment and registered by the laser scanner’s light collector. The instruments are classified as two types of measurement techniques: the impulse (or Time of Flight – TOF) technique and the phase-based technique. The scanning systems are thus divided into either TOF or phase based scanners. There are also systems on the market that combine both techniques. Both approaches have their own individual advantages that make them more advantageous for certain applications.
Using the TOF technique, the measurement pulses are modulated onto a carrier wave and the time between sending and receiving is measured. The distance is calculated from the time difference. Advantages of the TOF technique are the longer range and the greater eye safety. The strengths of the TOF scanners are thus measuring of large distances.
Using the phase based method, emitted waves with different wave lengths are compared with each other and the phase difference is used to determine the traveled distance. The advantages of the phase based method are the very high measurement speed, higher precision and resolution. The method is especially useful for the measurement of complex continuous geometries at a limited distance.
Colored scans are also possible. An external or internal camera is used to take pictures which are calculated onto the point cloud. Every point, defined by its x, y and z coordinates, is assigned its own color information (r, g, b). The quality of the results depends on the recording configuration and the calibration of the camera. Systems with an external camera do not have the same recording centers for camera and scanner. This difference needs to be corrected in a mechanical or computational way.
Other systems have the camera built into the beam path of the laser.