Unmanned aerial systems (UAS’s) and in particular intelligent, autonomous rotorcraft and fixed-wing aircraft have the potential to significantly impact modern society. A few examples of their utility include aerial surveying in difficult-to-access terrain, precision agriculture, package delivery, moviemaking, infrastructure inspection, fire fighting, search and rescue, etc.
All these applications depend on advancements in vehicle autonomy that will fully automate many of the vehicles functions, including route planning, navigation, obstacle avoidance, landing zone evaluation, autonomous take-off and autonomous landing.
The UAS market is forecast to explode into hundreds-of-thousands of units within just a few years of the FAA establishing the appropriate regulatory procedures for the operation of UAS in the National Air Space (NAS). “An enhance capability for safe, autonomous take-off and landing will fuel the market’s forecast growth. Technology ensuring the safe operation of UAS, particularly during the first and last 50 ft. of flight, will contribute to testing that verifies the safety of UAS operations as well as providing regulators, legislators, and the general public with increased confidence in UAS operations,” says NASA.
UAVs have become indispensable to modern militaries in providing intelligence, near-real time reconnaissance and surveillance to commanders, and offering warfighters greater battlespace awareness. They have proven effective in electronic combat support, battle damage assessment and even in national security operations like border surveillance, low intensity conflict and guerilla / terrorist warfare. The ability to take-off and land in tactical cluttered environments will allow UAS to be used more extensively in support of forward military units.
Raytheon wins $255M US Navy Contract for precision approach and landing
Raytheon Co. (RTN) has been awarded a $255 million contract by the U.S. Navy for development and production readiness of [the U.S. Navy’s] next generation precision landing system. RTN said it will provide the U.S. Navy with a Joint Precision Approach and Landing System (JPALS) that leverages GPS satellite navigation “to provide more accurate landing guidance for manned and unmanned aircraft, replacing radar and beacons used in older systems.
“RTN stated JPALS technology “improves navigational alignment prior to approach, allowing aircraft to land on any aircraft carrier or amphibious assault ship, day or night, even in adverse weather conditions. As such, RTN will supply the U.S. Navy with JPALS technology for both manned and unmanned aircraft, RTN noted.
Lockheed Martin to develop autonomous take-off and Landing technologies for Unmanned Aircraft
The office of Naval Research has awarded a $13.5 million contract to an industry team led by Lockheed martin to develop autonomous technologies for take-off and Landing for aircraft.
Some of the autonomous technologies have already been demonstrated by K-max, an unmanned aircraft with marines which is being currently used in Afghanistan. The developed technologies under this five year contract shall also be useful as decision aid to pilots on legacy manned aircrafts.
Under the contract, Lockheed Martin and a team of industry, government and academic partners shall develop technology that will interact with human operator at a high level while the low level control shall be handled autonomously. The team shall demonstrate in first 18 months the capabilities of its Open-Architecture Planning and Intelligence Architecture for Managing Unmanned Systems (OPTIMUS) . This architecture is designed to be platform agnostic and was developed under Army’s Autonomous Technologies for Unmanned Air System program
Integration of Unmanned Aircraft systems in the National Airspace System (NAS)
While the technology for unmanned air vehicles operating day in and day out without constant human supervision is maturing steadily, much remains to be done to make these vehicles commonplace. NASA has identified a number of challenges that must be addressed for these vehicles to safely and efficiently conduct their tasks in the National Airspace System (NAS).
Civilian applications of UASs must ensure that they can:
1. Sense and avoid other vehicles and follow air traffic commands,
2. Avoid the terrain and land without operator intervention,
3. React to contingencies such as engine out and lost link scenarios, and
4. Be reliable and cost-effective.
NASA had issued earlier a proposal for Autonomous, Safe Take-Off and Landing Operations for Unmanned Aerial Vehicles in the National Airspace, “We propose to a combination of software algorithms and low-cost, low SWAP sensors that simultaneously solves the navigation and obstacle detection problem, especially as relates to operation in cluttered environments.” That is, in this program we will show that it is possible for small autonomous air vehicles to reliably and safely fly in the first and last 50 feet of operation.
NASA Licenses New Autonomous Technology for Unmanned Aircraft
NASA has developed technology that may enable unmanned aircraft to fly safely in the national airspace along with piloted aircraft through its program called Unmanned Aircraft Systems in the National Air Space or UAS in the NAS. The patent-pending integrated communications and control system is capable of collision warnings as well as real-time traffic and weather updates.
Potential NASA and non-NASA commercial applications
Additionally, the commercial market is forecast to grow to as many as 160,000 UAS. As soon as UAS operation in the national airspace is fully implemented, the cargo transportation market, in particular, is forecast to be the largest market segment. Autonomous precision take-off and landing will be a key enabling technology in realizing this market
The proposed autonomous technology will enable greater utilization of UAS in other NASA areas, particularly for experimentation and testing in the various research centers, for example expanding the utilization of UAS in the Ames FINESSE volcano research. The mature technology will ultimately enable greater use of UAS in space. A UAS that knows its position and is able to set down, avoiding obstacles in a cluttered environment can be used to accomplish repairs both inside and outside a spacecraft, as well as performing exploration of planetary surfaces.
Military UAS requirements are well documented and tens-of-thousands of UAS are already in use worldwide. The ability to take-off and land in tactical cluttered environments will allow UAS to be used more extensively in support of forward units.
Electronic System Laboratory’s Autonomous aircraft landing under crosswind conditions
Electronic System Laboratory under Department of Electrical and Electronic Engineering at Stellenbosch University in South Africa has completed many projects on unmanned aerial vehicles, including autonomous take-off and landing of fixed-wing and rotor aircraft.
The main contribution of this project is the development of a robust control system with excellent disturbance rejection capabilities that will allow for accurate landing of a fixed-wing aircraft under crosswind conditions. Control system techniques that were implemented in previous projects at the ESL were not explicitly designed to land an aircraft under adverse atmospheric conditions; rather, landing tests were conducted during ideal or close-to-ideal wind conditions. This project will therefore focus on the development of robust controllers implemented in a way that exploits the advantages of various crosswind landing techniques.
L3 Communication’s Viking 400-S
The L3 Viking 400-S Unmanned Aircraft System (UAS) is integrated with Autonomous Take-Off and Landing (ATOL) technology supplied by L3 Unmanned Systems’ flightTEK system. The UAS operates for up to 12 hours and can be equipped with up to 100 pounds of payload technologies, including chemical, biological, radiological and nuclear (CBRN) detectors to protect officers responding to a man-made incident, such as a dirty bomb detonation. UAS payloads carrying high-resolution cameras can capture bird’s-eye images of a an incident, which can help commanders identify a suspect’s location and deploy resources with full-situational awareness, such as whether a suspect is armed or hard-hit areas and prioritize resources. Images captured are transmitted wirelessly back to into a GIS software suite for mapping an affected area and later reporting needs.
Autonomous Technologies survey
Mohammad Khaled Salameh Al-Sharman in his report “Auto takeoff and precision landing using integrated GPS/INS/OPTICAL flow solution” surveyed and compared Some of the technologies that have been utilized for autonomous takeoff and landing :
- AVATAR Helicopter:Novatel RT -20 DGPS, CCD camera and Ultrasonic sensors provided Landing with 47 cm average position error. However the solution is very expensive and computationally heavy.
- Yamaha RMAX helicopter:CCD camera mounted on an off the shelf, Gyros & accelerometers. It provided Landing with 43 cm average position error (54 cm maximum position error). However the solution is computationally heavy (two PC104 stacks with 700 MHz processors) hence Works with a high payload helicopters.
- Small scale helicopter:IMU and Range sensor were used for Auto takeoff and landing with 0.5 m altitude error. However Ultra sonic sensor is not that accurate at high altitudes.
- ASCTec Hummingbird Quadrotor:IMU, Infrared Camera, IR LEDs placed in T-shape. 50 indoor VTOL flight tests were conducted, the standard deviation is less than 3 cm in each position axis. The solution will not work properly in outdoor environments. The camera should be close enough to the pattern to detect the IR spots
- Mini Quadrotor : Optical flow sensor, GPS, IMU, Sonar sensor. Position stabilization for the Quadrotor at the final meter before touching ground. No estimator was designed.
- Cheetah Quadrotor:PX4FLOW Sensor, IMU, Hovering and outdoor flight trajectory. It shows better results comparing to the previously designed optical flow sensors. The output flow is auto-compensated for the 3D rotations
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