Implementation of a Flash-LADAR aided inertial navigator

GPS aided inertial systems can provide high accuracy position and attitude information in many operational scenarios; however, their use is limited to environments where GPS signals are available. An alternative method can be based on the use of Flash-LADAR or other 3D imaging sensor data to navigate in the GPS-devoid environments or the integration of these 3D imaging sensors with an inertial measurement unit. Flash LADAR (laser radar) and 3D imaging technology consists of a laser or light transmission source that is being emitted over a relatively large aperture coupled with a focal plane array detector capable of creating an ldquoimagerdquo of the observed scene where each pixel not only has an associated intensity value but also an estimate of the range to the observed object. With the recent development of short-range low-cost (Lt $10 k) 3D imager technology, the use of such technology to aid a low-cost inertial measurement unit (IMU) has become practical and of great interest. Current low-cost 3D imager or Flash LADAR technology is capable of greater than 100 times 100 pixel resolution with 5 mm depth resolution at a 30 Hz frame rate. From this 3D range, features such as planar surfaces created by the walls, lines created where planes intersect, and points from the intersection of lines can be measured with high precision. In this paper we will focus the discussion on the 3D imager feature extraction performance aspects and lay the basis for the image and IMU-based feature association and integration architecture. Data from an indoor test will be utilized to illustrate some of the concepts explained in this paper..