UAS Over Our Moana

Enhancing Public Safety in Hawaiian Waters with UAS

            Hawaii welcomes over seven million visitors each year who partake in many activities throughout the islands. In a five year study at the Queens Memorial Hospital researchers found that almost 23% of the 8244 admitted patients had water-related injuries. Visitors comprise only 12.6% of the population at any given day but accounts for over 44% of total admissions in hospitals for water-related injuries, “water-related injury rates are significantly higher for Hawai'i's visitors than residents” (Ho, Speck, & Kumasaki, 2009). Although the Hawaiian Government, through its Ocean Safety and Lifeguard Services Division (OS&LSD), exerts great effort in ensuring coverage of the most popular swimming areas it cannot cover every stretch of beach or body of water. Some of the most popular swimming, snorkeling, surfing, boarding, kayaking, wind-surfing, and diving spots are beyond sight of manned lifeguard posts, a few that are completely off the beaten path attract some because of its seclusion and the challenge it brings to the adventurous spirit of others. Add to this the growing number of water-related companies catering to tourists and locals alike, the chances of incidents and accidents ebb and flow with the tide of tourists who come to enjoy the warmth and Aloha of Hawaii. Clearly there is a need to augment and help the OS&LSD perform its duties to ensure water safety for the masses. This is where unmanned aerial systems (UAS) come in.

            There are many discussions about the numerous uses of UAS outside the military. Civilian practical applications of UAS are growing; perhaps one area where UAS will be of benefit is to augment lifeguards. UAS can patrol lengthy coastlines and beaches beyond sight of lifeguard towers; it can issue warnings before swimmers get into dangerous situations, or even drop flotation devices to those in distress. One such design is a Pars UAS made by RTS Ideas. The Pars drone underwent testing at the Caspian Sea in August 2013. It can deliver a number of life vests or flotation devices it carries as payload; can fly for 10 minutes at a speed of up to 7.5 meters per second and at a range of about 4.5 km. The Pars is light and inexpensive; it uses bright LEDs for illumination and to make it visible during night operations. Launch and recovery is possible from land or from a boat. RTS hopes to make its drone available in the near future (Pars Tests at Caspian Sea, 2013).

            Surf Life Saving Australia is testing various UAS to aid in patrolling its vast coastline and beaches. Partnering with an Australian company, V-TOL Aerospace, various platforms are in consideration to help patrol Australia’s 11,000 beaches (World's first ’Eye in the sky’ boosts beach safety, 2014). V-TOL Aerospace’s 1m wingspan “mini-Warrigal” and its 2.1m wingspan “Warrigal Explorer” can provide surveillance search and rescue support to lifesavers. The V-TOL “Arrow” is a 5m long heavy lift VTOL platform capable of carrying 100kg payload such as advanced sensors or rafts and other lifesavers. V-TOL also has quad rotor and octocopters in its lineup of UAS platforms, all sold as a system consisting of the aerial platform, cameras and software, ground station with its associated software systems and a launcher. When used together with manned search and rescue platforms these UAS systems provide extended lifeguard coverage capable of dropping life saving devices, detecting watercraft accidents, spotting predators, and notifying lifeguards to respond to emergencies (Unmanned Aircraft Systems: Aerial Robotic Devices, 2014).

            Using UAS to safeguard the public is not without challenges. Considerations for financing, training, regulatory requirements and restrictions, legal and ethical use must be addressed before UAS can take to the skies. Procurement, training, maintenance, lifecycle management, and operational costs can be a major factor in employing UAS for lifeguard purposes which usually rely on local government funding. Will the benefits of using UAS outweigh the cost when compared to hiring more lifeguards and building more lifeguard towers?

            Lifeguards, or operators of UAS in lifeguard duties, must also carefully consider which role UAS will play in the performance of their duties, whether it is patrolling or surveillance duties only or limited lifesaving duties such as dropping life vests, to search and rescue missions using bigger UAS platforms. Safety considerations are always a factor when operating any machinery around people. Lifeguards must ensure flight paths are as far away as possible from general public or structures to minimize damages or injury in case of failure. Privacy concerns will also surface, most likely from private personal dwellings close to observation areas than from beachgoers. The possibility of vulnerability to hacking is also a concern in both catastrophic failure and privacy encroachment scenarios. Along with proper training and operations, secure encrypted communications and system reliability are vital in UAS to prevent legal ramifications from impeding its widespread use in public safety and lifesaving duties around our Moana.

References

Ho, H., Speck, C., & Kumasaki, J. (2009, December). Visitor Injuries in Hawaii. Retrieved from PubMed.Gov: http://www.ncbi.nlm.nih.gov/pubmed/20034256

Pars Tests at Caspian Sea. (2013, October 13). Retrieved from RTS Ideas: http://rtsideas.com/index.php?option=com_k2&view=item&id=7:pars-test-at-caspian-sea&lang=en

Unmanned Aircraft Systems: Aerial Robotic Devices. (2014, April 30). Retrieved from V-TOL Aerospace: http://www.v-tol.com/page/unmanned-aircraft-systems/default.asp

World first ’Eye in the sky’ boosts beach safety. (2014, April 30). Retrieved from Surf Life Saving Australia: http://sls.com.au/content/world-first-%E2%80%99eye-sky%E2%80%99-boosts-beach-safety

Detect, Sense, and Avoid

     Air traffic control centers (ATCC) take responsibility for managing, takeoff and landing, and separation of manned aircraft operating within the national airspace (NAS) using ground-based radars at terminal radar control (TRACON) and air route traffic control centers (ARTCC). Along with voice communications with pilots Traffic Alert and Collision Avoidance Systems (TCAS) aboard most aircraft help maintain safe distances to avoid potential collision dangers. In the middle of all these technology sits the human factor, pilots and Air traffic controllers (ATC), using their senses and brain computing power to maintain safe operations in the air and on the ground. ATCs have an unenviable, highly stressful, job of ensuring the safe operation of over 90,000 planes flying across the U.S. everyday (over 5, 000 aircraft flying overhead at any given time), according to the National Air Traffic Controllers Association. In spite of the increasing density of air traffic pilots and ATCs manage to effectively perform their jobs to monitor aircraft and maintain separation.

      UAS operators, in essence, must play both parts to prevent collisions. As pilots of UAVs they must have situational awareness of their aircraft’s surroundings using flight cameras and instrumentation readings, all from the vantage point far removed from the aircraft itself. They must also perform as quasi ATCs in conjunction with other operators to maintain separation in segregated airspace. In non-segregated airspace, though, UAV operators must comply with local ATC instructions if they are to operate safely within the vicinity of commercial and general aviation (GA) aircraft. Communications between all involved must maintain a high degree of reliability and incorporate failsafe measures on the UAV. This is particularly important on the mid to upper size categories of UAVs where the potential for catastrophic collisions increases proportionally.

     Automatic Dependent Surveillance-Broadcast (ADS-B), currently in use and will be required on all commercial and GA aircraft by the year 2020, takes the sense and avoid capabilities of aircraft to the next level (Automatic Dependent Surveillance-Broadcast (ADS-B), 2014). Augmenting transponders, which can serve as backup, ADS-B can significantly enhance the UAVs’ ability to detect, sense and avoid other aircraft on the grid makes an argument for allowing safe integration into the NAS. Yet, this technology comes at a cost and may not be applicable to all UAV categories. The equipment necessary to utilize ADS-B adds weight and power demands on the UAV. While these requirements may be negligible on medium range to MALE/HALE UAV designs, they are of note when incorporating into smaller unmanned platforms where space, weight, and power are at a premium. The effect of the additional demands on the system comes into consideration compared to endurance or payload capacity.

      In looking towards integration of its UAS into the NAS, the US Air Force issued a request for information to technology vendors to build sense and avoid systems for its drones, called the Common-Airborne Sense and Avoid (C-ABSAA) Program (Cooney, 2014). The AF seeks alternatives to the Certificate of Authorization process and increase its mission options as military and commercial use of UASs expands. This, however, only addresses one issue of the many facing UAV integration into the NAS to include ensuring reliable command, control and communications, failsafe actions in loss-link situations, network security and anti-jamming or anti-spoofing capabilities, and interference issues in saturated RF spectrum. These are just a few issues that the UAS industry and aviation and government agencies face with the challenge of integration of UAVs into the NAS.

Reference

Automatic Dependent Surveillance-Broadcast (ADS-B). (2014, April 16). Retrieved from Federal Aviation Administration: http://www.faa.gov/nextgen/implementation/programs/adsb/

Cooney, M. (2014, April 17). Layer 8. Retrieved from Network World: http://www.networkworld.com/community/blog/air-force-wants-technology-will-let-drones-sense-and-avoid-other-aircraft

Heavy UAV

A UAS is to be designed for precision crop-dusting. In the middle of the design process, the system is found to be overweight.
• Two subsystems – 1) Guidance, Navigation & Control [flying correctly] and 2) Payload delivery [spraying correctly] have attempted to save costs by purchasing off-the-shelf hardware, rather than a custom design, resulting in both going over their originally allotted weight budgets. Each team has suggested that the OTHER team reduce weight to compensate.
• The UAS will not be able to carry sufficient weight to spread the specified (Marketing has already talked this up to customers) amount of fertilizer over the specified area without cutting into the fuel margin. The safety engineers are uncomfortable with the idea of changing the fuel margin at all

 

 

In a requirements based design process such as in the scenario described above it is vital to break down high level requirements, such as those promoted by the marketing department and management, into more design-specific lower level instructions and be able to communicate them clearly to subsystem design teams (Loewen, 2013). The design must meet prescribed requirements without sacrificing performance or safety, which in turn set lower level design parameters not met by the two subsystem teams. Weight is an important factor in aviation; it affects all aspects of aircraft design from propulsion, aerodynamics, structure, capacity and load, performance, and endurance, to name a few. The weight of all aircraft components, to include fuel and payload, goes into consideration when calculating center of gravity and ensuring the designed aircraft limits are not exceeded.

 

As the Systems Engineer (SE) in this scenario it is important to plainly communicate the requirements of the project to the entire group, that requirements based design does not tolerate slip ups (Loewen, 2013). While the use of commercial off-the-shelf (COTS) equipment saved some cost it did not succeed in meeting design limitations. Clearly, both teams in question will need to get back to the drawing board. Subsequent research and development (R&D) can move a step further by searching for even lighter alternatives to other components of the UAV. For example, materials used for airframe have evolved from the use of wood and canvas to aluminum to titanium to composite materials (Unmanned Aircraft Systems Roadmap, 2005). In essence, using lighter and stronger materials for aircraft structures as weight-saving alternatives is preferred in aircraft design. The teams can also search for innovative weight-cutting alternatives for other components of the UAV. However, the priority is to meet initial requirements first and get the final product out the door, while saving product enhancements for later versions. For example, using the fuselage or wing as the antenna can cut almost the entire weight of a traditional antenna system. Reducing weight even further will net improvements in payload capacity, performance, and operational costs which can make for desirable “nextgen” versions.

Reference

 

Loewen, H. (2013). Requirements-‐based UAVDesign Process Explained. MicroPilot, 1-17.

Unmanned Aircraft Systems Roadmap. (2005). Washington, DC: Office of the Secretary of Defense.