Development and flight test of terrain-referenced guidance with ladar forward sensor

Zelenka, Richard E.; Clark, Raymond; Zirkler, Andre; Saari, Ron; Branigan, Robert G.

doi:10.2514/3.21705

Cited by 15 publications

(3 citation statements)

References 3 publications

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“…However, this method was only suitable for such a special mechanism. It is worth noting that terrain features have been used to achieve terrain following for military aircraft (Theunissen, Koeners, Rademaker, Jinkins, & Etherington, ; Zelenka, Clark, Zirkler, Saari, & Bragan, ), and bottom mapping/map matching (Cancilliere, ) has been used for underwater vehicles when GPS signals were lost. Resembling terrain following and bottom mapping/map matching, this research presents a new localization method in which the inclination characteristics of the terrain are considered as the features of the surroundings.…”

Section: Related Workmentioning

confidence: 99%

Terrain-inclination-based Three-dimensional Localization for Mobile Robots in Outdoor Environments

2014

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A new terrain‐inclination‐based localization technique is proposed in this paper to enable a robot to identify its three‐dimensional location relative to measurable terrain inclinations. Given a topographical map and a planned path, a robot‐terrain‐inclination model (RTI model) is extracted along the path on the terrain upon which the robot is operating. A particle filter is then used to fuse the measurement data with the robot motion based on the extracted RTI model for either a three‐wheeled or a four‐wheeled mobile robot. Experiments were carried out in four outdoor scenarios: one short path with different initial conditions and map resolution, another short path with different surface roughness and sensor accuracy, and two long paths with different types of rigid terrains and multiple loops. Experimental results show that the proposed method could achieve good localization performance on inclined outdoor terrains.

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Section: Related Workmentioning

confidence: 99%

Terrain-inclination-based Three-dimensional Localization for Mobile Robots in Outdoor Environments

2014

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“…The scanning, pencil-beam MMW radar allows a terrain and obstacle database to be constructed and presented to the pilot as a synthetic perspective display. Such a high-resolution, high accuracy database could also be used to drive higher-level low-altitude guidance [6]. The synthetic perspective display would be of greatest benefit during flight operations in unfamiliar areas, such as those encountered during heli-borne emergency medical service (EMS), search and rescue, military special operations and airborne fire-fighting missions, or during degraded weather operations.…”

Section: Introductionmentioning

confidence: 99%

<title>Affordable MMW aircraft collision avoidance system</title>

1997

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Collision avoidance is of concern to all aircraft, requiring the detection and identification ofhazardous terrain or obstacles in sufficient time for clearance maneuvers. The collision avoidance requirement is even more demanding for helicopters, as their unique capabilities result in extensive operations at low-altitude, near to terrain and other hazardous obstacles. To augment the pilot's visual collision avoidance abilities, some aircraft are equipped with "enhanced-vision" systems or terrain collision warning systems. Enhanced-vision systems are typically very large and costly systems that are not very covert and are also difficult to install in a helicopter. The display is typically raw images from infrared or radar sensors, and can require a high degree of pilot interpretation and attention. Terrain collision warning systems that rely on stored terrain maps are often of low resolution and accuracy and do not represent hazards to the aircraft placed after map sampling. Such hazards could include aircraft parked on runway, man-made towers or buildings and hills. In this paper, a low cost dual-function scanning pencil-beam, millimeter-wave (MMW) radar forward sensor is used to determine whether an aircraft's flight path is clear of obstructions. Due to the limited space and weight budget in helicopters, the system is a dual function system that is substituted in place of the existing radar altimeter. The system combines a 35GHz forward looking obstacle avoidance radar and a 4.3 GHz radar altimeter. The forward looking 35 GHz 3-dimensional radar's returns are used to construct a terrain and obstruction database surrounding an aircraft, which is presented to the pilot as a synthetic perspective display. The 35GHz forward looking radar and the associated display was evaluated in ajoint NASA Honeywell flight test program in 1996. The tests were conducted on a NASA/Army test helicopter. The test program clearly demonstrated the systems potential usefulness for collision avoidance.

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“…Reference [5] develops a ladar designed for path planning and obstacle avoidance. Reference [6] develops a forwardlooking ladar to assist a helicopter pilot in obstacle detection and path planning. A laser range finder is used in [7] to detect unknown obstacles.…”

Section: Introductionmentioning

confidence: 99%

Vision-based local multi-resolution mapping and path planning for Miniature Air Vehicles

Beard

Byrne

2009

2009 American Control Conference

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Miniature Air Vehicles (MAVs) are often used for low altitude flights where unknown obstacles might be encountered. Path planning and obstacle avoidance for MAVs involve planning a feasible path from an initial state to a goal state while avoiding obstacles in the environment. This paper presents a vision-based local multi-resolution mapping and path planning technique for MAVs using a forward-looking onboard camera. A depth map, which represents the timeto-collision (TTC) and bearing information of the obstacles, is obtained by computer vision algorithms. To account for measurement uncertainties introduced by the camera, a multiresolution map in the body frame of the MAV is created in polar coordinates. Using the depth map, the locations of the obstacles are determined in the multi-resolution map. Dijkstra's algorithm is employed to find a collision-free path in the body frame. The simulation and flight test results show that the proposed technique is successful in solving path planning and multiple obstacles avoidance problems for MAVs.

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Development and flight test of terrain-referenced guidance with ladar forward sensor

Cited by 15 publications

References 3 publications

Terrain-inclination-based Three-dimensional Localization for Mobile Robots in Outdoor Environments

Terrain-inclination-based Three-dimensional Localization for Mobile Robots in Outdoor Environments

<title>Affordable MMW aircraft collision avoidance system</title>

Vision-based local multi-resolution mapping and path planning for Miniature Air Vehicles

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