The term unmanned aerial vehicles (UAVs), in modern age, is used to point our attention to the military utility vehicles controlled without an on board aircrew. However the applications of such kind of objects is not only limited to the military use as oil fields surveys and general purpose surveillance have also employed UAVs as an iconic tool to flourish their business. The UAVs we hear about today, have evolved through an iterative process as those developed some ninety to hundred years ago were simple and of basic type, owing to the fact that technology wasn’t that much advanced as it is today.
The very first kind of UAVs known to world were of balloon shaped used to carry some warhead to the enemy’s territory and were intelligently triggered to accomplish the assigned mission from a remote end. This was the modified war strategy used in world war one, however not hundred percent successful. To mitigate the limitations of previously developed UAVs and to enhance the level of intelligence of the vehicle, efforts were made in the post world war one era to develop aerial torpedoes which ultimately led to the modern form of cruise missiles used in world war two.
It is important here to describe the two major forms of UAVs i.e. Intelligent missiles and Drones and the distinguishing factor is the type of mission and recovery of the vehicle. The former kind is used for destruction purposes (self plus target) only and the later one is primarily used in surveillance and reconnaissance and the vehicle is recovered after mission. With time, the second category found its further division into three major classifications known as
- Pilotless aerial systems such as target drones which are used for training purposes only
- Nonlethal UAVs which are used only for espionage and surveillance purposes.
- Unmanned combat aerial vehicles which along with surveillance capabilities are also equipped with ammunition to hit the target with pin point accuracy.
Why are they called Unmanned vehicles? The simple answer is there is no onboard pilot sitting in the aircraft to fly it and a more elaborated argument is that these objects are fully autonomous having a flight control computer which itself decides the path of the aircraft without instantaneous human input as the mission is already fed into the computer. Giving the aircraft eyes (cameras), Sense of touch (the pressure sensors), the sense of being self aware (the guidance mechanism) eliminates the need of human inputs during flight thus making it fully autonomous vehicle which can take off, complete a mission and come back home by itself.
The evolution of shape, performance and purpose continued to develop new age drones powered by jet engines and being aided by the most sophisticated sensors and payloads. The early versions were propeller engines based and some of which are still used by the oilfield companies to monitor the daily activities, are used by the battlefield commanders to observe the activities of enemy and much more. The problems faced by the developers include endurance, flight stability and accurate autonomous landing. It took a fairly long time to address the limitation of endurance until UAVs industry deployed jet engines and electronically controlled fuel injection systems which provided extra hours for the missions. Initially mechanical gyroscopes were used as a guidance tool but accuracy problems caused many accidents. New era UAVs are equipped with high accuracy electronic gyros in conjunction with military standard GPS systems which helped enormously in achieving accuracy milestones which were merely dreamed of in the past.
The efforts inaugurated some hundred years ago in the form of balloons and torpedoes have been resulted now in the form of Predator, Reaper(an evolved version of Predator) and Global Hawk which are some examples of the best UAVs know to the world at current time. These vehicles have provided up to 30 hours mission endurance HD images and video capturing aided with night vision and target locking capabilities. Technology is stepping ahead by leaps and bounds and so is the case with the unmanned vehicles because current efforts in this industry are leading towards a networked UAVs platform being controlled by a single ground station which is the predicted future of UAVs.