ABSTRACT
An unmanned aerial vehicle (UAV) is known by various names, such as a remotely piloted aircraft (RPA), an unattended air system (UAS), or simply a drone. Essentially, a UAV is considered an aircraft without a human pilot [1]. All aerodynamic functions can be controlled by onboard sensors, a human operator in the ground control location, or the deployment of autonomous electronic and electro-optical (EO) systems. The most basic functions of a military UAV include intelligence, reconnaissance, and surveillance (IRS). However, an unmanned combat air vehicle (UCAV) is supposed to meet combat-related functions in addition to IRS capabilities, such as target tracking and deployment of defensive and offensive weapon systems against targets. A civilian UAV can be equipped with simple electronic and physical sensors such a barometer, GPS receiver, and altimeter device. Sophisticated UAVs are equipped with photographic, television, infrared (IR), and acoustic equipment, compact synthetic aperture radar (SAR), LIDAR laser along with radiation, chemical and other special sensors to measure pertinent parameters to accomplish critical missions. Navigation and control sensors are of critical importance. Furthermore, the onboard sensors can be controlled by the ground-based operator, preprogrammed sensors, or automated remote operating mode. In the case of UCAV mode, mission requirements can be changed by the ground operator. UAV design scientists believe that when using the onboard and groundbased equipment, UAVs can perform a wide range of missions, such as intelligence gathering, surveillance, reconnaissance, aerial mapping, antiterrorist activities, and emergency operations with remarkable speed. Scientists further believe that the development of
compact inertial navigation equipment, exotic software, and algorithmic maintenance for equipment calibration, filtering, and rapid and accurate processing of navigational information will enable UAV operators to perform important tasks with great accuracy and speed. Electrical design engineers are deeply involved in the specific development of onboard software and hardware of the next generation of computer vision and pattern recognition for navigation and UAV orientation. When the needed sensors and equipment are fully developed and available, UAVs can be equipped to create highly accurate images of the mouths of rivers, coastlines, ports, and settlements in critical regions. Typical physical parameters of a miniature UAV known as a nano-or micro-UAV, which can be launched by hand, are summarized as follows. Typical physical parameters of mini-UAVs [1]
• Takeoff weight: 6-12 lb • Airframe weight: 5-7 lb • Wing span: 5-7 ft • Fuselage length: 4-6 ft • UAV speed: 20-30 mph • Payload: 5-10 lb • Flight endurance: 10-25 h • Rating of electrical motor: 1 kW or 1.35 HP (some UAVs use
gasoline engine and some use an electric motor) • Takeoff speed: 15-20 mph • Landing speed: 15-20 mph • Runway length: 40-60 ft • Maximum climb speed: 16 ft/s • Turn radius: 35-50 ft • Flight altitude: 50-5000 ft
There are various types of unmanned vehicles currently in operation. Unmanned vehicles can be characterized by the aerodynamic configuration of the vehicles and their operational functions. Some UAVs are designed to provide surveillance or reconnaissance functions and generally operate at low altitudes. Specially designed and developed
unmanned vehicles are equipped with EO and electromagnetic sensors and weapon systems to provide combat capabilities. Note that combat UAVs generally operate at medium and high altitudes, while UAVs or drones generally fly at low altitudes ranging from 300 to 600 ft.
