A new approach to a laser ranger for underwater robots

Abstract

This paper describes the development of a laserbased ranging device, as part of a sensor work package that is to be integrated into an autonomous underwater vehicle. The objective of the laser ranging component includes robust operation in turbid ocean environments from 1 to 10 meters with a balance of accuracy and speed. A calibration technique that utilizes a spline interpolation is employed as an accurate, yet simple alternative to conventional triangulation methods. The resulting configuration is capable of range detection witbin 2% absolute error, at a 10 Hz refresh rate, out to 4 meters in turbid ocean conditions, and to greater than 10 meters in air. The maximum underwater range of the system is currently limited by the existing hardware, whereas the software is ready for any future system upgrades.

Study of Underwater Large-Target Localization Based on Binocular Camera and Laser Rangefinder

“…The measuring range of the binocular camera on land is 0.1 m-15 m. Different wavelengths absorb light to different degrees underwater, with the blue-green wavelengths absorbing the least underwater [25]. In the literature [26], the power of a red laser is about ten times that of a green laser, but the high absorption of the red wavelength severely limits the maximum detection range. Considering this effect, underwater lidar also selects blue-green light as the operating wavelength to effectively minimize the absorption of light by water [27].…”

Altitude control of an underwater vehicle based on computer vision

“…Since the laser beams reflections must be visible from a significant distance the absorption of the light is a problem that must be considered. In [24], a test in fresh water was done in order to compare the green laser and red laser properties. The red laser shows a power of about ten times the power of the green laser, but its high absorption rate severely impacts its maximum range.…”

Vision-Based Autonomous Underwater Vehicle Navigation in Poor Visibility Conditions Using a Model-Free Robust Control

“…Sensor systems play a relevant role in the development of AUV navigation systems as they provide information about the system status and/or environmental conditions. There exist several sensors that provide relevant and accurate information [5][6][7]. However, global or local pose estimation of underwater vehicles is still an open problem, specially when a single sensor is used.…”