List of Findings and Recommendations
A complete list of the committee’s findings and recommendations appears below in the order they appear in the body of the report
CHAPTER 2 The Uninhabited Air Vehicle as a System
Recommendation. The U.S. Air Force should establish a research and development program to develop fundamental technologies that will advance the use of UAVs by enabling them to carry out unique missions or by providing significant cost savings.
Finding. The USAF Scientific Advisory Board has provided a comprehensive analysis of the USAF’s needs and potential missions for UAVs. This analysis of short-term and midterm needs was the basis for the committee’s assessment of long-term technical and operational requirements.
Finding. Communications and data processing are not limiting technologies for the development and operation of military UAVs. Available technologies can accommodate the needs of currently conceived missions, and developments under way in the telecommunications community will be able to satisfy the needs of expanded military missions for UAVs.
Finding. The design decision that has the most profound effect on the human-machine sciences is degree of autonomy.
Recommendation. The U.S. Air Force should continue to strengthen its activities on human-machine science related to the design and development of UAVs. Research should be pursued in the following key areas:
integration of human-machine systems into the design process, including (1) the optimal and dynamic allocation of functions and tasks and (2) determination of the effects of various levels of automation on situational awareness
human performance, including (1) the investigation of human decision-making processes, (2) the development of methods to define and apply human-performance measures in system design, and (3) the enhancement of force structure through improved methods of team interaction and training
information technologies, including (1) the determination of the effects of human factors on information requirements and presentation and (2) the development of enhanced display technologies to improve the human operator’s ability to make effective decisions
CHAPTER 3 Aerodynamics
Recommendation. The U.S. Air Force should focus aerodynamic research on the following areas to maximize the benefit to future UAVs:
boundary-layer research focused on issues important to UAVs, including (1) transition prediction with (three-dimensional) pressure gradients, Reynolds numbers, and Mach numbers typical of UAV flight conditions and (2) improved flow modeling with part-chord natural laminar flow
techniques for real-time flow sensing and actuation
design architectures for complex multidisciplinary problems, including highly integrated systems
aeroelastic analysis and design approaches, especially for very flexible, unrestrained, actively-controlled aircraft
novel vehicle control concepts, including flow control
exploitation and modeling of unsteady, nonlinear, three-dimensional aerodynamics
design concepts for very low Reynolds numbers, including steady and unsteady systems
aerodynamic modeling concepts for designing vehicle control systems
CHAPTER 4 Airframe Materials and Structures
Recommendation. To support the development and introduction of probabilistic methods for UAVs, the U.S. Air Force should sponsor research on (1) analytical
tools, (2) characterization and testing, (3) simulation methods, and (4) design criteria.
Recommendation. As part of an integrated approach to vehicle configuration and structural design, the U.S. Air Force should conduct research to develop a fundamental understanding of design and analysis methods for aeroelastic tailoring of composite structures. This capability will be especially important for high-altitude, long-endurance configurations.
Recommendation. The U.S. Air Force should monitor the progress of the Composites Affordability Initiative and conduct research to develop a fundamental understanding of processes with promise for UAV structures.
Recommendation. The U.S. Air Force should conduct research to develop a fundamental understanding of metals processes applicable to UAV structures, such as research on low-cost processing of UAV airframe components.
Recommendation. The U.S. Air Force should expand the suite of materials and processes for use in small, low-cost vehicles to include very low-cost, commodity-grade materials that are not used in conventional aircraft constructions.
Recommendation. The U.S. Air Force should develop computational models for new materials and processes and apply them to UAVs.
Recommendation. The U.S. Air Force should develop improved health monitoring technologies that take advantage of recent advances in sensors, controls, and computational capabilities. Specific opportunities include the following:
microelectrical mechanical systems (MEMS) and mesoscale technologies for integrated sensor-actuation-control devices
improved load and condition-monitoring capabilities that use piezoelectric sensors and neural networks for data analysis
active flutter suppression and buffet load suppression systems that link condition-monitoring capabilities with piezoelectric transducers/actuators and intelligent controls
CHAPTER 5 Propulsion Technologies
Recommendation. The U.S. Air Force should include research on propulsion systems for UAV applications in its long-term research program. The following general research topics should be included:
high-altitude propulsion technologies, which may include gas turbines, internal combustion engines, solar-powered motors, or fuel cells
propulsion systems for small, highly maneuverable vehicles, including vertical takeoff and landing (VTOL) capabilities
computational modeling capability to reduce the need for engine testing during development
cost-reducing technologies that, for example, reduce parts count and complexity
The following specific research topics should be considered:
low Reynolds number turbomachinery, which is very important for both high-altitude operation and very small vehicles
low Reynolds number heat rejection for high-altitude coolers and for cooling very small propulsion systems at lower altitudes
turbomachinery tip clearance desensitization (for highly loaded engines, high-altitude operation, and very small systems)
desensitization to leakage and better, cheaper seals to reduce cost and enhance performance for highly maneuverable and very small vehicles
thrust vectoring for highly maneuverable vehicles
magnetic, air, and solid lubricated bearings to improve long-term storage, enhance high-altitude operation, and reduce complexity and cost
technologies for low-cost accessories, which tend to dominate the cost of smaller engines
low-cost vapor and liquid cooling schemes and affordable high-temperature materials (e.g., structural, magnetic, and electronic materials)
more effective cooling technologies for small engines
CHAPTER 6 Power and Related Technologies
Finding. No fundamental research issues related to the generation of power aboard UAVs must be resolved to enable generation-after-next vehicles.
CHAPTER 7 Control Technologies
Recommendation. In light of the special factors driving the design of UAVs, the U.S. Air Force should strengthen its support for basic research programs addressing the rapid (automated) design and implementation of high-performance control laws. Areas of interest include basic theory for nonlinear and adaptive control, reusable control law structures and processes capable of full-envelope design, software tools for automated control design and analysis, automated code
generation from high-level design tools, and simulation models with sufficient fidelity for affordable tests and verifications.
Recommendation. The U.S. Air Force should pursue basic research to provide scientific support for robust vehicle-management functionality.
Recommendation. The U.S. Air Force should enhance the capabilities of available design tools and planning aids by supporting ongoing efforts related to realtime path planning and optimization algorithms, and by embarking on a program of basic research in control of dynamic networks.
Recommendation. Motivated by the urgent need for a better understanding of the role of uncertainty in virtual engineering, the U.S. Air Force should establish a basic research program in uncertainty management.
Recommendation. The U.S. Air Force should monitor developments in microelectromechanical systems (MEMS) and undertake research to develop and apply a new generation of MEMS sensors and actuators.
CHAPTER 8 Research on Vehicle Subsystems
Recommendation. The U.S. Air Force long-term UAV research program should focus on crosscutting subsystem technologies.
Recommendation. As the long-range plans and priorities for UAVs emerge, the U.S. Air Force should include the applicable research opportunities in the long-range research program.