LWIR passive perception system for stealthy unmanned ground vehicle night operations

Abstract

Resupplying forward-deployed units in rugged terrain in the presence of hostile forces creates a high threat to manned air and ground vehicles. An autonomous unmanned ground vehicle (UGV) capable of navigating stealthily at night in offroad and on-road terrain could significantly increase the safety and success rate of such resupply missions for warfighters. Passive night-time perception of terrain and obstacle features is a vital requirement for such missions. As part of the ONR 30 Autonomy Team, the Jet Propulsion Laboratory developed a passive, low-cost night-time perception system under the ONR Expeditionary Maneuver Warfare and Combating Terrorism Applied Research program. Using a stereo pair of forward looking LWIR uncooled microbolometer cameras, the perception system generates disparity maps using a local window-based stereo correlator to achieve real-time performance while maintaining low power consumption. To overcome the lower signal-to-noise ratio and spatial resolution of LWIR thermal imaging technologies, a series of pre-filters were applied to the input images to increase the image contrast and stereo correlator enhancements were applied to increase the disparity density. To overcome false positives generated by mixed pixels, noisy disparities from repeated textures, and uncertainty in far range measurements, a series of consistency, multi-resolution, and temporal based post-filters were employed to improve the fidelity of the output range measurements. The stereo processing leverages multi-core processors and runs under the Robot Operating System (ROS). The night-time passive perception system was tested and evaluated on fully autonomous testbed ground vehicles at SPAWAR Systems Center Pacific (SSC Pacific) and Marine Corps Base Camp Pendleton, California. This paper describes the challenges, techniques, and experimental results of developing a passive, low-cost perception system for night-time autonomous navigation.

Long Range 3D with Quadocular Thermal (LWIR) Camera

“…We follow this path and compare our results with those published in Lee et al [18]. They used a pair of the FLIR Tau 11 640 × 512 cameras at a baseline of 0.75 m with the ground truth data provided by a LIDAR.…”

“…LWIR-only 3D perception is beneficial for the military applications where active ranging methods (LIDAR, time-of-flight (ToF) or structured light) are easily detectable by the properly equipped adversary. 3D perception for unmanned ground vehicle (UGV) was researched by Lee et al [18], Zapf et al [34], and while the experimental rig was tri-modal, they evaluated LWIR-only performance too while using LIDAR data as a ground truth.…”