(1) fixed wing

Advantages: the longest battery life, the highest flight efficiency and the largest load.

Disadvantages: You must run up and slide when landing.

(2) helicopters

Advantages: vertical takeoff and landing

Disadvantages: no advantage in battery life, complicated mechanical structure and high maintenance cost.

(3) Multi-rotor

Advantages: vertical take-off and landing, simple mechanical structure and easy maintenance.

Disadvantages: worse load and battery life.

General mechanical characteristics:

What's the difference between a quadrotor and a hexarotor?

? There is no essential difference, 3 moments+tension.

? Six-rotor control distribution is more flexible

(1) UAV: abbreviated as "Unmanned Aerial Vehicle" or "UAV" in English, it is an unmanned aircraft operated by radio remote control equipment and its own program control device. The English word "Drone" stands for micro UAV.

(2) Model aircraft: In the competition rules formulated by the International Air Transport Federation, it is clearly stipulated that "an aviation model refers to an aircraft that is heavier than air, has a size limit, has an engine, can be remotely controlled and cannot carry people."

(1) Hover

Wherein the propellers 1 and 3 rotate counterclockwise; 2, 4 rotate clockwise

? Tension counteracts gravity.

? The rolling and pitching moments produced by the pulling force of the four propellers are zero.

? The yaw moment is zero, and the reaction torque effect of the four propellers is offset.

Most helicopters, that is, single-rotor helicopters, have a small vertical tail rotor to offset the reaction moment, or use * * * axis twin propellers to rotate the upper and lower propellers in opposite directions, thus offsetting the reaction moment between them.

(2) Lifting movement

At the same time, if the rotational speed of the four propellers increases by the same amount, the total pulling force generated by the propellers will also increase, and the sum of the moments will still be zero.

When the tension is greater than gravity, the quadrotor aircraft will rise.

Left hand remote sensing controls up and down, and right hand remote sensing controls left and right movement.

(3) back and forth movement

At the same time, reducing the rotational speed of propellers # 1 and #4 by the same amount and increasing the rotational speed of propellers #2 and #3 by the same amount will cause the quadrotor aircraft to tilt forward. Then, the pulling force will produce a forward component.

Decreasing the rotational speed of #2 and #4 propellers by the same amount, and increasing the rotational speed of # 1 and #3 propellers by the same amount will make them fly forward and backward and left and right.

Torque is zero. However, the clockwise yaw moment increases and the plane yaws clockwise.

(1) comparison

(2) Limitations (this method should not be extended to large multi-rotors)

1) The larger the blade size, the more difficult it is to change its angular velocity quickly.

Therefore, the multi-rotor method should not be extended to large size, and the improved method is like Volocopter VC200.

Times make heroes, and multi-rotor is the product of the times.

All-in-one machine changed the experience and simplified the flight.