China Civil UAV Theory Questions — Questions 183–192

Option analysis: ① Navigation control: a function of the navigation subsystem in the navigation and flight control system, not of the flight control subsystem. ② Mission information collection and transmission: the textbook lists the flight control subsystem function as 'information collection and transmission' — not accurate. Mission information collection and transmission is a mission equipment function. ③ UAV attitude stabilization and control: textbook p. 27 original text, one of the three required flight control subsystem functions. Knowledge point: flight control subsystem functions: ① UAV attitude stabilization and control [required]; ② completing track control in coordination with the navigation subsystem; ③ UAV takeoff and landing control; ④ UAV mission equipment management and control; ⑤ UAV flight management [required]; ⑥ emergency control [required]; ⑦ information collection and transmission.

Textbook p. 27. The navigation and flight control system is divided into the navigation subsystem and the flight control subsystem. Airspeed and attitude angle relate to flight control; latitude and longitude relate to navigation.

A four-stroke engine burns fuel directly; a two-stroke engine burns a mixture of gasoline and lubricating oil. In a two-stroke engine, air and the fuel-oil mixture enter the engine through the same passage. The mixture must burn in the cylinder to produce power, and it also lubricates and cools to protect engine components.

Study note: with angular rate, choose it directly (GPS is the first choice for position). Textbook p. 29, §4, Position sensors. Typical position sensors: inertial navigation equipment, GPS satellite navigation receivers, magnetic heading sensors. Further reading: ① Inertial navigation: a technology that measures the aircraft's acceleration and automatically integrates it to obtain instantaneous velocity and position data. All equipment of an inertial navigation system is installed inside the vehicle; it works without external information and without radiating energy outward, is not easily disturbed, and is an autonomous navigation system. ② GPS is a passive satellite navigation system. In a passive ranging system, the user antenna only needs to receive navigation and positioning signals from the satellites to measure the distance or distance difference from the user antenna to the satellites. This ranging method, in which transmitting and receiving ranging signals are located in two different places, is called passive ranging. Using the measured station-to-satellite distances and the known satellite orbital positions, the user antenna's three-dimensional position can be calculated. ③ A magnetic compass gives the UAV a sense of direction. It provides data on the magnetic field experienced along the X, Y and Z axes; the data is then fed into the microcontroller's algorithm to provide a heading angle relative to magnetic north, and this information can be used to detect geographic orientation.

Maximum takeoff weight, also called 'maximum takeoff gross weight,' is the maximum limit on the aircraft's total weight at the start of the takeoff roll, set according to aircraft structural strength, engine power and other factors. Two aircraft with the same maximum takeoff weight but different empty weights can carry different payload weights. Rule out A. Empty weight is the weight of an aircraft carrying no payload (including fuel / ammunition / cargo / passengers, etc.). It has nothing to do with mission payload. Rule out B. Payload capacity is the maximum weight of payload a UAV can carry. Mission equipment is UAV payload, so payload capacity is the most accurate criterion. C is correct.

Main functions of the UAV ground station: command and control, and mission planning. The UAV ground station system does not include the onboard radio station. The UAV ground station system consists of control-station modules with different functions, mainly: ① Command processing center: plan formulation, data processing and application. ② UAV control center: flight manipulation, mission payload control, data link control, communication and command. ③ Payload control center: controls only the onboard mission equipment. Exam method: the onboard radio station is on the aircraft, not on the ground — choose C.

Textbook p. 42, §2.2.2, Display systems. Option analysis: ① The ground station's flight control seats, mission equipment control seats, and data link management seats each have display devices for the corresponding subsystems, matching the question's 'aircraft status,' 'payload status,' and 'link status.' ② The UAV ground station itself has no ability to sense airspace information and cannot provide airspace information. Rule out B. ③ There is no pilot on the UAV, so the ground station does not display pilot status. Rule out C.

Study note: with normal fuel supply, choose it. An aircraft fuel booster pump is an important part of the aircraft fuel supply system, mainly used to increase fuel pressure so fuel reaches the pressure range the engine needs for normal operation. Without a booster pump, gravity feed works when the aircraft is level, but it is unstable, and discontinuous fuel supply may occur when attitude changes.

Study note: the original three parts are the power source, the power distribution system, and the electrical equipment.

Study note: flight control and communication (the aircraft flies, the control station manages, the communication link carries in between). A typical unmanned aircraft system consists of the aircraft platform, the control station, the communication link, and any other components specified in the approved type design.