Ultra-low-altitude flight device and ultra-low-altitude flight method thereof

Abstract

The invention relates to a super-low-altitude flight device and a super-low-altitude flight method thereof. The ultra-low-altitude flight device comprises a cabin body and a control device. Lifting ducted fan arrays are symmetrically arranged on the two sides of the cabin body, and a forward ducted fan combination is arranged on the rear portion of the cabin body. The control device is connected to the lifting ducted fan array and the forward ducted fan combination and used for controlling the lifting ducted fan array to blow air flow downwards to the ground and perpendicular to the ground / water surface so that the cabin body can be emptied by 0.3-0.6 m, and controlling the forward ducted fan combination to blow air flow backwards and parallel to the ground / water surface to drive the cabin body to advance at the speed lower than 5 m / s. According to the ultra-low-altitude flight device, movement force needed by flight is decomposed into lifting force perpendicular to the ground / water surface direction and traction / braking force parallel to the ground / water surface direction through a movement system decomposition means, the lifting force and the traction / braking force are achieved through independent systems respectively, ultra-low safety risks can be guaranteed, the energy utilization efficiency of a power system is improved, and the energy utilization efficiency of the power system is improved. Therefore, the method is economical and efficient.

Description

Technical Field

[0001] The present invention relates to the technical field of ultra-low altitude flight, and in particular to an ultra-low altitude flight device and an ultra-low altitude flight method thereof. Background Art

[0002] In the field of flight, people have always been accustomed to moving freely in the air at high altitudes and high speeds. Therefore, humans can fly to higher and higher spaces, fly at higher and higher speeds, and perform various agile flight movements. However, a problem that always accompanies them is safety, especially for manned flights. Therefore, how to vigorously develop flight application scenarios while ensuring flight safety has become a prominent issue facing people.

[0003] The current thinking of the industry is to adopt various technical means to increase flight safety to cope with the increasing flight safety risks, which leads to high flight costs. The human dream of flying still requires great courage to realize.

[0004] Even for the currently emerging flying cars, although they have also been reduced to a low altitude of hundreds of meters, flying at this altitude is still enough to cause life-threatening accidents. And the pursuit of high speed has exacerbated this risk. At the same time, the current conception of flying cars generally adopts a deformable configuration design, such as telescopic, folding, etc., as well as various speed change devices, which not only increases the dead weight, which is extremely unfavorable for the efficient operation of flying cars, but also has a complex structure, resulting in reduced reliability and increasing the probability of failures during flight and thus causing disasters to life and property.

[0005] In reality, there are many application scenarios that do not require high-speed and high-altitude operation, such as flying facilities in entertainment venues.

[0006] In summary, the high-altitude and high-speed thinking that is popular in current flight practice not only has the dilemma of high safety risks, but also cannot cover all scenarios of flight practice. It is necessary to correct and supplement it. Summary of the invention

[0007] In view of the problems existing in the prior art, the purpose of the present invention is to provide an ultra-low altitude flying device and an ultra-low altitude flying method thereof, which have a simple structure, high energy utilization rate and improved flight safety.

[0008] In order to achieve the above object, the present invention adopts the following technical solution:

[0009] An ultra-low altitude flying device, comprising a cabin and a control device;

[0010] A lifting ducted fan array is symmetrically arranged on both sides of the cabin, and the lifting ducted fans on the same side of the array rotate in the same direction and opposite to the lifting ducted fans on the other side; when each fan in the fan array on one side rotates, it generates a lifting force of equal magnitude and an angular momentum of equal magnitude and opposite direction with the fans at the corresponding position in the fan array on the other side when rotating at the same speed; a forward ducted fan combination is arranged at the rear of the cabin;

[0011] The control device is respectively connected to the lifting ducted fan array and the forward ducted fan combination, and is used to control the lifting ducted fan array to blow air vertically downward to the ground so that the cabin is lifted 0.3-0.6 meters, and to control the forward ducted fan combination to blow air horizontally backward to drive the cabin forward at a speed lower than 5 meters per second.

[0012] Furthermore, the output power of the lift ducted fan and the forward ducted fan can be adjusted.

[0013] Furthermore, the lifting ducted fan and the forward ducted fan both include a duct and a circular straight air cylinder of the same size connected to the duct or a conical air cylinder whose axial cross-sectional area gradually shrinks.

[0014] Furthermore, the lifting ducted fan array on each side of the cabin includes at least three lifting ducted fans, and the at least three lifting ducted fans are arranged on the side of the cabin in sequence along the length direction of the cabin and perpendicular to the ground / water surface.

[0015] Furthermore, a sled-type landing support is provided under the cabin body. When the sled-type landing support lands, the ducted fan is lifted to a certain height off the ground.

[0016] Furthermore, the forward ducted fan combination includes two first forward ducted fans at the bottom and one second forward ducted fan at the top arranged in an equilateral triangle, the inlet planes of the two first forward ducted fans are perpendicular to the upper plane of the cabin, and the planes where the axes of the two first forward ducted fans are located are at a certain distance below the upper plane of the cabin, so that the pitch moment generated by the forward thrust is as small as possible; the two forward ducted fans rotate in opposite directions, thereby generating equal forward thrusts and equal and opposite angular momentums when rotating at the same speed; the control device controls the two first forward ducted fans and the one second forward ducted fan to work individually or jointly.

[0017] An ultra-low altitude flying method comprises the following steps:

[0018] The ducted fan array is lifted to blow air vertically downward to the ground so that the cabin is lifted 0.3-0.6 meters;

[0019] After the cabin is vacated, the forward ducted fan blows air horizontally backward to drive the cabin forward at a speed of less than 5 m / s.

[0020] Furthermore, when the flight angle needs to be adjusted, the lifting duct fan arrays on both sides of the cabin are controlled to output different powers so that the two sides of the cabin are subjected to different lifting forces.

[0021] Furthermore, when turning is required, thrusts of different magnitudes are generated by adjusting the two fans of the first forward ducted fan to rotate in opposite directions and at different speeds, thereby generating a net turning torque on the horizontal plane to drive the cabin to turn.

[0022] Furthermore, when deceleration or braking is required, the two first front ducted fans are turned off, and the second front ducted fan is controlled to reverse and blow airflow forward horizontally to generate braking force; when flight acceleration is required, the two first front ducted fans and the second front ducted fan are turned on at the same time to blow airflow backward.

[0023] In general, the present invention has the following advantages:

[0024] The ultra-low altitude flight device of the present invention utilizes the motion system decomposition method to decompose the motion force required for flight into a lifting force in the direction perpendicular to the ground / water surface and a traction / braking force in the direction parallel to the ground / water surface, and each of them is realized by an independent system: the lifting force is mainly obtained by blowing air downwards from the lifting duct fan arrays arranged symmetrically on both sides of the cabin body, and the traction force is obtained by blowing air backwards from the forward duct fan combination at the rear of the cabin, so that the ultra-low altitude flight device can fly at an ultra-low altitude of about 0.5 meters at an ultra-low speed of less than 5 meters per second. Ultra-low speed means that not only ultra-low safety risks can be guaranteed during operation, but also the aerodynamic resistance is negligible, and the power expenditure is almost completely used to bear the lifting of the ultra-low altitude flight device, which is conducive to improving the energy utilization efficiency of the power system. When transporting the same personnel and items, the ultra-low altitude flight device of the present invention not only has extremely low safety risks, but also the energy consumed is basically only required to bear the energy consumption of lifting these personnel and items in the air, while other high-speed carrying equipment not only faces higher safety risks, but also needs to bear the consumption of work done by the aerodynamic friction resistance caused by these personnel and items passing through the air at high speed.

[0025] Moreover, when operating at ultra-low speed, due to the decomposition of the motion system, the incoming flow direction and the rotation plane of the fan blades of the lifting ducted fan array responsible for generating the lifting force are nearly perpendicular when the fan blades rotate, and the incoming flow is nearly uniform, so that the incoming flow is uniform in space and therefore stable in time. The blade vibration phenomenon caused by the inherent periodic variable load of ordinary propellers and high-speed ducted fans due to the parallel rotation surface and the incoming flow direction will not occur, which helps to ensure the stable, safe, efficient and comfortable operation of the lifting ducted fan array. The ultra-low altitude flight method realized by this method has clear principles and significant effects, and has low safety risks, low energy consumption, low noise, eco-friendly, broad-spectrum applicability, simple and easy operation, and is therefore economical and efficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic structural diagram of the ultra-low altitude flying device of the present invention.

[0027] Figure 2 It is a schematic diagram of the principle of adjusting the flying height of the ultra-low-altitude flying device of the present invention.

[0028] In the figure:

[0029] 1-cabin door; 2-lift ducted fan; 3-cabin body; 4-forward ducted fan; 5-sled landing support. DETAILED DESCRIPTION

[0030] The present invention will be described in further detail below.

[0031] like Figure 1 As shown, an ultra-low altitude flying device includes a cabin 3 and a control device; a lifting ducted fan array is symmetrically arranged on both sides of the cabin 3, and the use of the lifting ducted fan array can greatly reduce the probability of flight safety accidents caused by fan failure. During operation, the angular momentum balance can be ensured by only making the rotation directions of the fans at symmetrical positions opposite and equal in speed, and there is no need to use an additional vertical tail to offset the rotation of the main horizontal rotor in order to achieve angular momentum balance like a helicopter, which greatly simplifies the structure.

[0032] A forward ducted fan 4 assembly is provided at the rear of the cabin 3. The output power of the lifting ducted fan 2 and the forward ducted fan 4 can be adjusted. The lifting ducted fan 2 and the forward ducted fan 4 both include a duct and a circular straight wind tube connected to the duct or a conical wind tube with an appropriately contracted axial cross-sectional area to enhance the lifting force or traction force.

[0033] The control device is connected to the lifting ducted fan array and the forward ducted fan 4 respectively, and is used to control the lifting ducted fan array to blow air vertically downward to the ground so that the cabin 3 is lifted 0.3-0.6 meters;

[0034] When the cabin 3 is 0.3-0.6 meters in the air, the forward ducted fan 4 is controlled to blow airflow horizontally backward to drive the cabin 3 forward at a speed lower than 5 meters per second, thereby achieving an ultra-low altitude and ultra-low speed flight with extremely low safety risks.

[0035] This ultra-low-altitude flying device operates at an extremely low speed in the air about 0.5 meters above the ground or water surface, so it can be called an amphibious ship. Because amphibious ships have extremely low safety risks, they can allow for extremely simple structural designs, without the need for complex anti-collision structures and buffer systems, thereby greatly achieving the goal of lightweighting, which is crucial for flying platforms operating in the air, because for flying platforms, simple structures mean high carrying efficiency and high device reliability.

[0036] A sled-type landing support 5 is provided under the cabin 3, which can omit the braking system of the wheeled landing gear and prevent the amphibious ship from accidentally rolling when parked on a slope with a certain slope.

[0037] When the amphibious ship lands on the ground via the sled landing support 5, the ducted fan 2 is lifted to a certain height above the ground, preferably 5 cm.

[0038] The front part of the amphibious ship is provided with a hatch 1 which can be opened from the center to the outside on both sides for people or goods to get on and off or load and unload.

[0039] The rear of the amphibious ship is provided with an arc-shaped protruding baffle to prevent the clothing and hair of the crew members in the cabin 3 from being sucked in by the ducted fan at the rear.

[0040] The part where the manned / cargo frame of the amphibious ship is connected to the ducted fan is made of stainless steel, and the rest is made of fiberglass or fiberglass or carbon fiber, which ensures the structural strength while being as light as possible. This increases the load capacity of the amphibious ship, facilitates the operation and control of the amphibious ship, and further improves the energy efficiency per unit load.

[0041] When the ducted fan array on the side of cabin 3 is started, the airflow is ejected from the outlet below the wind tube, and the impact on the ground produces a recoil effect, forming a lifting force on cabin 3. When an appropriate number of fans are started at an appropriate speed so that the wind tube ejects an appropriate amount of airflow, the lifting force begins to be greater than the weight and load of cabin 3 itself, and cabin 3 begins to float from the ground. By synchronously and symmetrically increasing the number and speed of fans on both sides of cabin 3, cabin 3 can float to a higher height. The principle of side fan selection, quantity, and speed is that cabin 3 is about 0.5 meters above the ground to ensure extremely low safety risks.

[0042] To improve reliability, the lifting ducted fan array on each side of the cabin 3 includes at least three lifting ducted fans 2. At least three lifting ducted fans 2 are arranged on the side of the cabin 3 in sequence along the length direction of the cabin 3 and perpendicular to the ground / water surface, thereby improving redundancy and greatly reducing the probability of failure of a certain lifting ducted fan 2 or even a safety accident. At the same time, it also reduces the power specification of a single lifting ducted fan 2, which is conducive to better adjusting the amphibious ship to operate at a suitable height to adapt to the uneven ground / water surface.

[0043] The forward ducted fan 4 combination includes two first forward ducted fans and one second forward ducted fan. The inlet planes of the two first forward ducted fans are perpendicular to the upper plane of the cabin 3. The planes where the axes of the two first forward ducted fans are located are at a certain distance below the upper plane of the cabin, so that the pitch moment generated by the forward thrust is as small as possible; at the same time, they rotate in opposite directions, and when rotating at the same speed, they generate equal forward thrusts and equal and opposite angular momentums, so that the total angular momentum of the cabin 3 is zero, avoiding unnecessary rotation of the cabin 3 in the vertical plane around the length direction; a second forward ducted fan is located above the two first forward ducted fans; these three forward ducted fans are arranged in an equilateral triangle. The control device controls the first forward ducted fan and the second forward ducted fan to work individually or jointly.

[0044] When the cabin 3 is suspended to a suitable height, the two first forward ducted fans at the rear of the cabin 3 are started to spray air backwards toward the rear of the cabin 3, and the cabin 3 can move forward slowly at a controlled speed. During normal operation, it is only necessary to turn on the two first forward ducted fans at the bottom and operate them at an appropriate speed to ensure that the maximum forward speed of the cabin 3 does not exceed 5 meters per second, so as to ensure extremely low safety risks. The second forward ducted fan above serves as a backup and booster (the speed of the amphibious ship can be higher than 5 meters per second when boosted) to fly over water bodies or abnormal areas as quickly as possible, reducing the probability of failures and risks when flying over water bodies or abnormal areas. Incidentally, since the cabin 3 runs at an extremely low speed, most of the energy consumed is used to generate the energy for the jet airflow when lifting the cabin 3, so it is also an extremely economical mode of transportation.

[0045] When turning is required, the two first forward ducted fans are adjusted to rotate in opposite directions and at different speeds to generate thrusts of different magnitudes, thereby generating a net torque on the horizontal plane to drive the cabin 3 to turn. When deceleration or braking is required, the two first forward ducted fans are turned off, and the second forward ducted fan is controlled to reverse and blow airflow forward horizontally to generate braking force; when acceleration is required, the two first forward ducted fans and the second forward ducted fans are turned on at the same time to blow airflow backward.

[0046] Preferably, all ducted fans used in the amphibious ship have consistent geometric dimensions, which enhances the interchangeability of parts and is beneficial to the operation and maintenance of the amphibious ship.

[0047] An ultra-low altitude flying method comprises the following steps:

[0048] The ducted fan array is lifted to blow air vertically downward to the ground so that the cabin 3 is lifted 0.3-0.6 meters;

[0049] After the cabin 3 is lifted up by 0.3-0.6 meters, the forward ducted fan 4 blows air horizontally backward to drive the cabin 3 forward at a speed lower than 5 meters per second.

[0050] When the flight angle needs to be adjusted, the lifting duct fan arrays on both sides of the cabin 3 are controlled to output different powers so that the two sides of the cabin 3 are subjected to different lifting forces, which can make the left and right sides of the cabin 3 slightly tilted.

[0051] When turning is required, the two first forward ducted fans are adjusted to rotate in opposite directions at different speeds to generate thrusts of different magnitudes, thereby generating a net turning torque on the horizontal plane to drive the cabin 3 to turn. When deceleration or braking is required, the two first forward ducted fans are turned off, and the second forward ducted fan is controlled to reverse and blow airflow forward horizontally to generate braking force. When acceleration is required, the two first forward ducted fans and the second forward ducted fans are turned on at the same time to blow airflow backward.

[0052] Description of the mechanism for adjusting and maintaining the altitude of the amphibious ship:

[0053] like Figure 2 As shown, a lifting ducted fan 2 blows air to the ground. When the pressure difference ΔP between the lower surface and the upper surface of the ducted fan blowing downward vertically from the ground is sufficient to support the deadweight and load of the amphibious ship, that is, when the following conditions are met, we can deduce the relationship between the height of the lifting ducted fan 2 outlet from the ground and the size of the lifting ducted fan 2. These conditions are:

[0054]

[0055] In the above relationship, N is the total number of fans supported; R0 is the fan radius; ΔP is the fan static pressure; G _boat is the empty weight of the ship; G _load is the load of the ship.

[0056] As for the lifting ducted fan 2,

[0057]

[0058] In this relationship, ρ is the air density; g is the acceleration due to gravity; H max is the maximum static pressure head of the fan; Q is the fan volume flow rate; Q opt is the fan volume flow rate corresponding to the maximum static pressure head of the fan.

[0059] make

[0060]

[0061] In the above formula, ΔP _sherold It is the minimum fan static pressure that can lift the empty weight and load of the flight device.

[0062] The following can be obtained:

[0063]

[0064] When this flow condition is met,

[0065] Let the flow be Q, then according to the law of conservation of flow, there is the following relationship:

[0066]

[0067] Where V _tail ,V _exit They are respectively the outlet velocity of the lifting fan rotor and the escape velocity of the airflow from the fan outlet to the cylindrical escape surface between the ground / water surface. h is the height of the cylindrical escape surface of the airflow, which is the height between the fan outlet plane and the ground / water surface.

[0068] therefore:

[0069]

[0070] Also consider the Bernoulli equation:

[0071]

[0072] In the above formula, P loss They are the average static pressure on the circular plane at the fan rotor outlet, the average static pressure on the cylindrical escape surface, and the pressure loss during the airflow turning from the fan axial to the radial direction.

[0073] The upper end of the outlet and the incoming flow are at the same position, so their pressures are the same, and there is the following relationship:

[0074]

[0075] The lower end of the outlet is a solid wall, and its pressure is the impact stagnation pressure of the incoming flow.

[0076]

[0077] Assume that the outlet pressure is linearly distributed along the height, so the average pressure at the outlet is as follows:

[0078]

[0079] Substituting into the Bernoulli equation, we get the following equation:

[0080]

[0081] Substitute back to the relationship between the fan duct outlet and the ground height:

[0082]

[0083] As in the present invention, the function of the lower air duct of the lifting ducted fan 2 is to pull the outlet of the lifting ducted fan 2 lower and closer to the ground. The relationship of the height of the outlet of the air duct of the lifting ducted fan 2 from the ground derived here still holds true.

[0084] From the above relationship, it can be seen that the height of the duct outlet of the ducted fan 2 from the ground is significantly greater than 0.7 times the radius R0 of the ducted fan 2. The degree to which the height is 0.7 times higher than the radius R0 of the ducted fan 2 is directly related to the ratio of the flow loss of the duct airflow impacting the ground and the outlet kinetic energy, which depends on the acceleration / deceleration of the duct airflow and the intensity of the turning caused by the rotation of the fan. When the duct airflow speed is increased, the ratio of the aforementioned flow loss and outlet kinetic energy will increase accordingly and gradually reach a stable value. For the present invention, the radius R0 of the ducted fan 2 is set between 30 and 50 centimeters, which can ensure that the amphibious flying ship of the present invention can operate at a take-off height of about 50 centimeters.

[0085] From the above, it can be seen that the present invention realizes people's dream of safe and reliable flight by using the simplest device. At the same time, the present invention is also broad-spectrum, practical, economical and efficient.

[0086] Application Examples

[0087] Application example 1: Sports and entertainment equipment suitable for all ages in city parks. It allows people to fully experience the fun of flying. In particular, they can enjoy the excitement of flying over water and over slopes, thus becoming a new favorite for tourists in parks with water bodies and slopes.

[0088] Application Example 2: Inter-city and rural transportation without road restrictions. For plain and hilly areas, residents of suburban areas and mountain villages can take the safe and comfortable flying boat of the present invention when traveling and working.

[0089] Application Example 3: A patrol tool for border guards. In this specific application scenario, the ultra-low speed and ultra-low altitude characteristics of the present invention not only help border guards to understand the dynamic changes in the area near the patrol route in detail, but also because the present invention does not touch the ground during the flight process, it can prevent the soldiers from being harmed by mines secretly buried by the enemy.

[0090] Application Example 4: Some areas may face flood disasters caused by heavy rains, endangering the lives of people and requiring their transfer and evacuation. The amphibious ship of the present invention can provide a safe, reliable, efficient and low-cost transfer and evacuation equipment.

[0091] In general, the present invention has the following advantages: the amphibious ship of the present invention flies at an extremely low altitude above the ground, has the ability to cross the water, and also has the ability to operate smoothly on vast fields and hillsides with a certain slope, so it is an amphibious ship that takes into account the surface, water and air.

[0092] First, it uses mature ducted fan equipment, selects appropriate models and quantities, and uses the recoil lift method to make the amphibious ship float at a limited height from the ground, that is, about 0.5 meters. At the same time, the jet propulsion method is used to make the flying ship move forward slowly, so that the speed does not exceed 5 meters per second. This ensures that the flying ship has extremely low risks. Thus, a new safe and reliable track has been opened up in the field of low-altitude economy.

[0093] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are included in the protection scope of the present invention.

Claims

1. An ultra-low altitude flying device, characterized in that: including cabin and control device; A lifting ducted fan array is symmetrically arranged on both sides of the cabin; the lifting ducted fans on the same side of the array rotate in the same direction and in the opposite direction to the lifting ducted fans on the other side; when each fan in the fan array on one side rotates, it generates a lifting force of equal magnitude and an angular momentum of equal magnitude and opposite direction with the fans at the corresponding position in the fan array on the other side when rotating at the same speed; a forward ducted fan assembly is arranged at the rear of the cabin; The control device is respectively connected to the lifting ducted fan array and the forward ducted fan combination, and is used to control the lifting ducted fan array to blow air vertically downward to the ground so that the cabin is lifted 0.3-0.6 meters, and to control the forward ducted fan combination to blow air horizontally backward to drive the cabin forward at a speed lower than 5 meters per second.

2. The ultra-low altitude flying device according to claim 1, characterized in that: The output power of the lift ducted fan and the forward ducted fan can be adjusted.

3. The ultra-low altitude flying device according to claim 1, characterized in that: Both the lifting ducted fan and the forward ducted fan include a duct and a circular straight air cylinder connected to the duct or a conical air cylinder whose axial cross-sectional area gradually shrinks.

4. The ultra-low altitude flying device according to claim 1, characterized in that: The lifting ducted fan array on each side of the cabin body includes at least three lifting ducted fans, and the at least three lifting ducted fans are arranged on the side of the cabin body in sequence along the length direction of the cabin body and perpendicular to the ground or water surface.

5. The ultra-low altitude flying device according to claim 1, characterized in that: A sled-type landing frame is installed under the cabin. When the sled-type landing frame lands, it lifts the ducted fan to a certain height off the ground.

6. The ultra-low altitude flying device according to claim 1, characterized in that: The forward ducted fan combination includes two first forward ducted fans at the bottom and one second forward ducted fan at the top arranged in an equilateral triangle, the inlet planes of the two first forward ducted fans are perpendicular to the upper plane of the cabin, and the planes where the axes of the two first forward ducted fans are located are a certain distance below the upper plane of the cabin; the two first forward ducted fans have opposite rotation directions, and generate equal thrusts and equal and opposite angular momentums when rotating at the same speed; the control device controls the two first forward ducted fans and the one second forward ducted fan to work individually or jointly.

7. An ultra-low altitude flying method, characterized in that: The ultra-low altitude flying device according to any one of claims 1 to 6 is used, comprising the following steps: The ducted fan array is lifted to blow air vertically downward to the ground so that the cabin is lifted 0.3-0.6 meters; After the cabin is vacated, the forward ducted fan blows air horizontally backward to drive the cabin forward at a speed of less than 5 m / s.

8. The ultra-low altitude flying method according to claim 7, characterized in that: When the flight angle needs to be adjusted, the lift duct fan arrays on both sides of the cabin are controlled to output different powers so that the two sides of the cabin are subjected to different lift forces.

9. The ultra-low altitude flying method according to claim 7, characterized in that: When turning is required, different thrusts are generated by adjusting the two fans of the first forward ducted fan to rotate in opposite directions and at different speeds, thereby generating a net turning torque on the horizontal plane to drive the cabin to turn.

10. The ultra-low altitude flying method according to claim 7, characterized in that: When deceleration or braking is required, the two first front ducted fans are turned off, and the second front ducted fan is controlled to reverse and blow airflow forward horizontally to generate braking force; when flight acceleration is required, the two first front ducted fans and the second front ducted fan are turned on at the same time to blow airflow backward.

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