“Drones” can be classified into different types on there usage and structures like Drones for Photography, Aerial Mapping, Surveillance, Emergency Drones, etc. All types of drones mostly come under the following four types:
Fixed Wing Drones
Single Rotor Helicopter
Fixed Wing Hybrid VTOL
Multi-Rotor drones are the most common types of drones which are used by professionals and hobbyists. They are used for most applications like aerial photography, aerial video surveillance, etc. Multirotor drones are more stable in air and it can carry heavy payload.
Multi-rotor drones can be further classified based on the number of rotors on the platform.
Tricopter drones contain three rotors to get a stable flight in the air. The endurance of the drone is high and it flies faster.
Quadcopters are the most commonly used drones in the UAV industry. It contains four rotors to fly in the air. Most photography drones are based on quadcopter design. The advantage of these types of drones is that it is more stable, has high endurance, comparatively simple fabrication, and these types of drones are compact and portable.
Hexacopter contains six rotating rotors to lift the drone. These types of drones are commonly used in medium load carrying drones like surveillance, mapping, food delivery, First aid & medical purpose. These drones have medium-range and long endurance.
Octocopter contains eight rotating rotors to lift the drone. These types of drones are for heavy lifting and multipurpose drones like Agriculture fertilizer spraying, heavy load delivering, cinematic photography to handle large video cameras with gimbals. It has long endurance and long-range.
Fixed Wing Drones
Fixed Wing drones are entirely different in design and it looks like an aircraft. Fixed-wing drones are mostly used in military purposes for long-range and endurance. It can fly for a long time in the sky. The service ceiling of the fixed-wing drones is more high compare to other types of drones. This type of drone is used to carry a heavy load like missiles, bombs, airdrops, attack enemy aircraft, etc. The fixed-wing drone also comes in different structural types, designs, and a number of motor placement.
Most of the fixed-wing drones are operated remotely by the pilot in the ground stations. The other downsides of fixed-wing drones are higher costs & skill training required in flying. It’s not easy to put a fixed-wing drone in the air. You either need a ‘runway’ or a catapult launcher to set a fixed-wing drone on its course in the air. A runway or a parachute or a net is again necessary to land them back in the ground safely. On the other side, multi-rotor drones are cheap – anyone with a few hundred dollars to spare can buy a decent quadcopter. Flying a quadcopter doesn’t require special training. You just take them to an open area and fly it. Guiding and controlling a quadcopter can be learned on the go.
Single Rotor Drones
Single rotor drones look very similar in design & structure to actual helicopters. Unlike a multi-rotor drone, a single rotor model has just one big-sized rotor plus a small-sized one on the tail of the drone to control its heading. Single rotor drones are much efficient than multi-rotor versions. They have higher flying times and can even be powered by gas engines. In aerodynamics, the lower the count of rotors the lesser will be the spin of the object. And that’s the big reason why quadcopters are more stable than octocopters. In that sense, single rotor drones are much efficient than multi-rotor drones.
However, these machines come with much higher complexity and operational risks. Their costs are also on the higher side. The large-sized rotor blades often pose a risk (fatal injuries have been recorded from RC copter accidents) if the drone is mishandled or involves in an accident. Multi-rotor drones, often owing to their small rotor blades have never been involved in fatal accidents (though a scar on the human body is likely). They also demand special training to fly them on air properly (though they may not need a runway or a catapult launcher to put them on air).
These are hybrid versions combining the benefits of Fixed-wing models (higher flying time) with that of rotor based models (hover). This concept has been tested from around the 1960s without much success. However, with the advent of new generation sensors (gyros and accelerometers), this concept has got some new life and direction.
Hybrid VTOL’s are a play of automation and manual gliding. A vertical lift is used to lift the drone up into the air from the ground. Gyros and accelerometers work in automated mode (autopilot concept) to keep the drone stabilized in the air. Remote based (or even programmed) manual control is used to guide the drone on the desired course.
There are some versions of this hybrid fixed-wing model available in the market. However, the most popular one is a drone used in Amazon commercials (for its Prime delivery service).