China Civil UAV Theory Questions — Questions 386–395

An autogyro is not a helicopter and has no powerplant. An autogyro is an aircraft that relies on forward-moving blades for lift and uses a tail rotor for heading control. Its key feature is that even if the engine fails, lift from rotor autorotation still allows a safe landing.

Cyclic pitch control is helicopter control content.

Throttle up/down, left/right rotation (rudder), pitch (horizontal tail), left/right roll (ailerons).

Circling while climbing presents the circular track while gradually increasing the shot's perspective and variety, giving richer visual effects. Because altitude keeps changing, viewers see scenery and buildings from different angles, for a more vivid, three-dimensional experience.

Examples: emergency rescue and disaster relief — multi-axis aerial surveys of geological disasters, tethered UAV night lighting; military reconnaissance — extensive use of DJI UAVs for frontline reconnaissance and artillery calibration in the Russia-Ukraine war; police surveillance — rural anti-drug patrols checking illegal crops, public security patrols; entertainment — UAV light shows, UAV racing competitions; radio and television — film and television aerial photography.

A multirotor IMU typically contains three accelerometers and three single-degree-of-freedom gyroscopes (angular rate sensors) mounted on three orthogonal sensitive axes. Accelerometers detect acceleration signals on the carrier coordinate system's three independent axes (degrees of freedom: forward/back, left/right, up/down). Gyroscopes detect angular velocity signals relative to the navigation coordinate system (degrees of freedom: pitch, roll, yaw).

Flight controller software version differences can cause compatibility issues during use; channel forward/reverse logic settings affect control; flight controller software file size has no direct relationship with using the software.

In fully manual mode, the flight controller intervenes in neither the inner nor the outer loop; operation depends entirely on the pilot's manual control.

No-load voltage is the battery's voltage with no load at all; it does not reflect true in-flight voltage. Load voltage is the battery's voltage while powering all aircraft systems (motors, electronics, etc.); it more truly reflects actual in-flight voltage. “Used voltage” has no clear definition: it may mean the voltage drop after discharge, but that is not what OSDs usually display and is not information aircraft operation needs.

The jelly or water-ripple effect is caused by high-frequency vibration.