Middle and large unmanned aerial vehicle ejection device and ejection method

Abstract

The invention relates to the technical field of unmanned aerial vehicle launching, in particular to a medium-large unmanned aerial vehicle ejection device and ejection method. A medium and large unmanned aerial vehicle ejection device comprises a supporting platform provided with a sliding rail suitable for sliding of a tackle; the pulley is arranged on the sliding rail in a sliding manner; the lifting assembly is arranged on one side of the supporting platform and comprises a lifting driving structure connected with the supporting platform and a lifting platform connected with the lifting driving structure, and the lifting platform is suitable for being lifted to a first position flush with the tackle under the action of the lifting driving structure so as to convey the unmanned aerial vehicle to the tackle; or descending to a second position flush with the bottom of the supporting platform; and the overturning assembly is arranged on one side of the lifting assembly, rotationally connected with the lifting assembly and suitable for overturning the lifting assembly from a third position where the lifting assembly is folded on the supporting platform to a second position where the lifting assembly is arranged on one side of the supporting platform under the action of driving force. The invention provides a medium and large unmanned aerial vehicle ejection device and ejection method.

Description

Technical Field

[0001] The present invention relates to the technical field of unmanned aerial vehicle (UAV) launching, and in particular to a medium-to-large-sized UAV ejection device and ejection method. Background Art

[0002] Since medium and large UAVs have the advantages of high altitude and long flight time, real-time image transmission, small radar reflection surface, large mission load, and flexible operation and use, their proportion in weapon equipment systems will be higher in the near future. Therefore, achieving safe and reliable take-off of medium and large UAVs is one of the keys to the UAV tactics going to the battlefield, and it is also a hot issue in current research. At present, the commonly used catapult take-off methods include: rubber band catapult, pneumatic catapult, rocket boost and electromagnetic catapult. For small and medium-sized UAVs below 200kg, rubber band catapult and pneumatic catapult launch modes are usually used; for large UAVs above 1000kg, the research and development usually focuses on the electromagnetic catapult launch mode; and for medium and large UAVs of 200kg-1000kg, rocket boost and electromagnetic catapult launch modes are mainly used. However, rocket boost involves the application of pyrotechnics, which has certain risks, and electromagnetic catapult requires the equipment to have a complex power system, which is costly and has a large workload for safety assurance. With the continuous breakthroughs in motor and electronic control technology, the mass production of products ensures the economic reliability of the use of accessories, creating opportunities for the development of electric catapult products. However, due to structural limitations, existing electric ejection devices can only be used to launch small UAVs, but cannot be used to launch medium or large UAVs with heavier weight. Summary of the invention

[0003] Therefore, the technical problem to be solved by the present invention is to overcome the defect that the electric ejection device in the prior art is not suitable for medium and large UAVs, thereby providing a medium and large UAV ejection device and ejection method.

[0004] In order to solve the above technical problems, the present invention provides a medium-to-large UAV ejection device, comprising:

[0005] A supporting platform is provided with a slide rail suitable for the sliding of the pulley;

[0006] A pulley, slidably disposed on the slide rail;

[0007] A lifting assembly is provided on one side of the support platform, comprising a lifting drive structure connected to the support platform and a lifting platform connected to the lifting drive structure, wherein the lifting platform is adapted to rise to a first position flush with the pulley under the action of the lifting drive structure to transport the UAV onto the pulley, or to descend to a second position flush with the bottom of the support platform;

[0008] A flip assembly is arranged on one side of the lifting assembly. The flip assembly is rotatably connected to the lifting assembly and is suitable for flipping the lifting assembly from a third position folded on the support platform to a second position arranged on one side of the support platform under the action of a driving force.

[0009] Optionally, the lifting drive structure includes a support column rotatably connected to the flip assembly and a hydraulic cylinder connected to the support column, and one end of the lifting platform is connected to a piston rod of the hydraulic cylinder.

[0010] Optionally, a guide rail is provided on the pillar, and a guide block slidably matched with the guide rail is provided at one end of the lifting platform.

[0011] Optionally, the flip assembly is a rotary cylinder, and the middle part of the lifting drive structure is rotatably connected to the middle part of the rotary cylinder.

[0012] Optionally, it further includes a first driving structure and a second driving structure arranged on the supporting platform, the first driving structure drives the pulley forward through a first traction member, and the second driving structure drives the pulley to reset through a second traction member.

[0013] Optionally, the first driving structure is a permanent magnet synchronous motor, the second driving structure is a reset motor, the permanent magnet synchronous motor is connected to the pulley through a wheel set, the reset motor is connected to the pulley through a brake, and the permanent magnet synchronous motor, reset motor and brake are all connected to a controller.

[0014] Optionally, the slide rail comprises a plurality of sections connected in a folding manner, and two adjacent sections of the slide rail are connected by a pin when in a folded state, and are locked and fixed by a buckle when in an unfolded state.

[0015] Optionally, the supporting platform is a vehicle-mounted chassis.

[0016] A method for ejecting a medium or large UAV using the ejection device is also provided, comprising the following steps:

[0017] The output torque of the first drive structure is increased to a rated value and maintained within a first predetermined time, and the output power of the first drive structure is increased to a maximum power until the UAV reaches a preset speed, and the output torque of the first drive structure is reduced to zero within a second predetermined time, and the UAV takes off;

[0018] The output torque of the second driving structure is increased to a rated value within a third predetermined time, and the output power of the second driving structure is increased to a maximum power, so as to pull the pulley back at a constant speed at a constant speed;

[0019] The rated value of the output torque of the first drive structure is the same as the rated value of the output torque of the second drive structure, and the output power of the first drive structure is greater than the output power of the second drive structure.

[0020] Optionally, the first predetermined time is 300 ms, the third predetermined time is 100 ms, and the output power of the first driving structure is three times the output power of the second driving structure.

[0021] The technical solution of the present invention has the following advantages:

[0022] 1. The medium and large UAV ejection device provided by the present invention, before the UAV takes off, first the flip assembly drives the lifting assembly to flip from the third position folded on the support platform to the second position set on one side of the support platform, then the UAV slides onto the lifting platform, the lifting drive structure drives the lifting platform to rise from the second position flush with the bottom of the support platform to the first position flush with the pulley, the UAV slides onto the pulley, and the pulley drives the UAV forward to accelerate under the action of the driving force until it takes off. In this way, even if the weight of the UAV is large, it can be smoothly lifted onto the pulley, saving manpower; and after the launch is completed, the lifting assembly can be folded on the support platform, reducing the occupied space and facilitating transportation.

[0023] 2. In the medium and large UAV ejection device provided by the present invention, the guide rail on the pillar slides with the guide block on the lifting platform to provide support and guidance for the lifting of the lifting platform, thereby ensuring its smooth lifting.

[0024] 3. The medium and large UAV ejection device provided by the present invention has a first drive structure of a permanent magnet synchronous motor and a second drive structure of a reset motor. Compared with pneumatic ejection and electromagnetic ejection, it has a lower maintenance cost. Compared with rocket boosting, it has no pollution such as fuel gas and gunpowder residue, and the energy is clean.

[0025] The permanent magnet synchronous motor is connected to the pulley through the wheel set, the reset motor is connected to the pulley through the brake, and the permanent magnet synchronous motor, reset motor and brake are all connected to the controller. Therefore, by controlling the output power and output torque of the permanent magnet synchronous motor and reset motor, and the braking speed of the brake, the UAV can be launched and reset at different speeds and overloads, and has strong maneuverability.

[0026] 4. The medium and large UAV ejection device provided by the present invention has a slide rail comprising multiple sections that are folded and connected, which is convenient for storage and transportation.

[0027] 5. The ejection method provided by the present invention realizes the stability and rapid take-off of the UAV during launch and the uniform return during reset by controlling the output torque and power of the first drive structure and the second drive structure, so as to achieve the take-off speed of the UAV matching the preset index, and at the same time satisfy the adjustable overload of the device, and has the characteristics of convenient operation and strong maneuverability. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0029] Figure 1 A schematic diagram of the ejection device for medium-to-large UAVs provided by the present invention during storage and transportation;

[0030] Figure 2 A schematic diagram of the ejection device for medium-to-large UAVs provided by the present invention when in operation;

[0031] Figure 3 The figure is a schematic diagram of the installation of the pulley and the slide rail;

[0032] Figure 4 is a schematic diagram of a pulley;

[0033] Figure 5 This is a schematic diagram of the installation of the lifting assembly and the supporting platform;

[0034] Figure 6 This is a schematic diagram of the installation of the lifting assembly and the supporting platform from another angle;

[0035] Figure 7 is a schematic diagram of the lifting assembly being in a second position;

[0036] Figure 8 is a schematic diagram of the lifting assembly being in a third position;

[0037] Fig. 9 Schematic diagram of the connection of two sections of slide rails.

[0038] Description of reference numerals:

[0039] 1. Support platform; 2. Pulley; 3. Flip assembly; 4. Slide rail; 5. Support column; 6. Pin shaft; 7. Buckle; 8. Limit plate; 9. Roller; 10. Brake; 11. First drive structure; 12. Second drive structure; 13. Suspension rod; 14. Mounting table; 15. Lifting platform; 16. Pillar; 17. Hydraulic cylinder; 18. Guide block; 19. Diagonal brace; 20. Lug. DETAILED DESCRIPTION

[0040] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0041] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0042] like Figures 1 to 9 A specific implementation of the ejection device for medium and large UAVs is shown. The medium and large UAVs in this embodiment weigh 200kg-1000kg and include a support platform 1 and a pulley 2, a lifting assembly and a flip assembly 3 arranged on the support platform 1. The support platform 1 in this embodiment is a vehicle-mounted chassis, that is, the entire device is arranged on a vehicle for easy transportation.

[0043] The support platform 1 is flat and has no guardrails, so as to facilitate the placement of the slide rails 4 suitable for the sliding of the trolley 2. A plurality of foldable support columns 5 can be added to the bottom of the support platform 1. The support columns 5 are folded when the vehicle is driving and supported under the support platform 1 when the drone needs to be launched to increase the load-bearing capacity. The slide rails 4 are arranged in multiple sections along the width direction of the support platform 1. In this embodiment, there are three sections. The number of slide rails 4 can also be increased or decreased according to the launch requirements. Fig. 9 As shown, the two adjacent sections of the slide rail 4 are connected by a pin 6 when in a folded state, and are locked and fixed by a buckle 7 when unfolded. Specifically, a pin seat is provided at each end of the connection between the two adjacent sections of the slide rail 4. The two pin seats are arranged up and down, and the shaft holes are aligned. The pin passes through the shaft holes of the two pin seats in sequence and is fixed by a nut, thereby realizing the rotation connection of the slide rails 4 at both ends. When the two sections of the slide rail 4 are opened to a position where the ends are aligned with each other, the buckle 7 provided at the end of one section of the slide rail 4 is overlapped and fixed in the block groove of the other end of the slide rail 4, thereby realizing the locking of the two sections of the slide rail 4. Of course, the fixing of the two sections of the slide rail 4 can also be achieved by means of snap-on or plug-in, and no specific limitation is made here.

[0044] The pulley 2 is an integrally formed flatbed trolley, on which a pair of limit grooves can be provided to prevent the drone from detaching from the pulley 2 before takeoff. A limit plate 8 can also be provided at the end of the pulley 2, which is detachably connected to the pulley 2 and slides to the front end of the slide rail 4 when the drone is launched, to prevent the pulley 2 from sliding off the front end of the slide rail 4 and causing damage. The pulley 2 is slidably arranged on the slide rail 4 through the rollers 9 provided at the bottom. Specifically, as shown in FIG. Figure 3 and Figure 4As shown, two grooves are provided at the bottom of the pulley 2, and rollers 9 are installed in the grooves. A brake 10 is coaxially installed on the roller 9 through a flange, and the pulley 2 can be controlled to decelerate by the brake 10. Figure 1 As shown, the bottom of the support platform 1 is provided with a first driving structure 11 and a second driving structure 12 along the forward direction of the pulley 2, the first driving structure 11 drives the pulley 2 forward through the first traction member, and the second driving structure 12 drives the pulley 2 to reset through the second traction member. Specifically, the first driving structure 11 is a permanent magnet synchronous motor, the second driving structure 12 is a reset motor, the permanent magnet synchronous motor is connected to the pulley 2 through a wheel set, the reset motor is connected to the pulley 2 through a brake 10, and the permanent magnet synchronous motor, the reset motor and the brake are all connected to the controller. A suspension rod 13 is provided between the two trough bodies, the wheel set is provided on the output shaft of the permanent magnet synchronous motor, the first traction member is a pull rope wound on the wheel set, and the other end of the pull rope is fixed on the suspension rod 13, thereby driving the pulley 2 to slide forward along the slide rail 4 to achieve the launch of the drone. A wheel set is also provided on the output shaft of the reset motor, another pull rope is wound on the wheel set, and the other end is fixed to the rear end of the pulley 2, thereby driving the pulley 2 to slide backward along the slide rail 4 to achieve reset.

[0045] The controller is arranged at the bottom of the supporting platform 1, and includes a frequency converter, a battery, a single-chip microcomputer, a sensor, and a data collector. The frequency converter controls the output torque and output power of the permanent magnet synchronous motor and the reset motor through cables; the battery can discharge at different rates according to the output power of the permanent magnet synchronous motor and the reset motor to supply power for them; the single-chip microcomputer controls the brake brake to stop the brake pulley, sends signals to the frequency converter, the lifting component, the flip component, the permanent magnet synchronous motor, and the reset motor, and can be encapsulated and formed into an operating handle. Personnel send instructions to control the frequency converter and the brake through the operating handle; the sensor is used to collect the speed and overload of the drone, and transmit it to the data collector to provide data for the closed-loop control of the ejection process. The permanent magnet synchronous motor, the frequency converter, and the battery adopt liquid cooling to dissipate heat. After entering the ejection process, the coolant flow of the above components can be increased to avoid overheating of the equipment, thereby reducing the risk of damage caused by it.

[0046] The lifting assembly is arranged on one side of the support platform 1, i.e., the rear end of the UAV launch direction. The end of the support platform 1 is provided with a mounting platform 14, the upper end surface of which is flush with the upper end surface of the pulley 2. A track can be arranged on the upper end surface of the mounting platform 14 to guide the UAV. Figure 5 and Figure 6As shown, the lifting assembly includes a lifting drive structure connected to the support platform 1 and a lifting platform 15 connected to the lifting drive structure. The lifting platform 15 is suitable for rising to a first position flush with the pulley 2 under the action of the lifting drive structure to transport the drone to the pulley 2, or descending to a second position flush with the bottom of the support platform 1.

[0047] Specifically, the lifting drive structure includes a support 16 rotatably connected to the flip assembly 3 and a hydraulic cylinder 17 connected to the support 16, and one end of the lifting platform 15 is connected to the piston rod of the hydraulic cylinder 17. The height of the support 16 is higher than the upper end surface of the mounting platform 14 to reserve the lifting space of the lifting platform 15. A support 16 is provided on each side of the mounting platform 14, and the installation space of the hydraulic cylinder 17 is reserved between the support 16 and the mounting platform 14. A guide rail is provided on the support 16, and the guide rail is arranged in the vertical direction. A guide block 18 is provided at one end of the lifting platform 15 to slide with the guide rail. The guide block 18 is L-shaped, one side of the L-shaped is slidably connected to the guide rail, and the other side of the L-shaped is fixed to the piston rod end of the hydraulic cylinder 17. The guide block 18 is arranged higher than the lifting platform 15 to increase the contact area with the guide rail and ensure the stability of lifting. In order to further improve the stability of lifting, a diagonal brace 19 can also be provided between the lifting platform 15 and the guide block 18. Of course, the hydraulic cylinder 17 can also be replaced by a gas cylinder or a telescopic rod, and the connection between the lifting platform 15 and the hydraulic cylinder 17 can also be a connection between a lead screw and a nut, which is not specifically limited here.

[0048] The flip assembly 3 is arranged at one side of the lifting assembly and is directly fixed on the mounting platform 14 by bolts or the like. The flip assembly 3 is rotatably connected to the lifting assembly and is suitable for flipping the lifting assembly from the third position folded on the support platform 1 to the second position arranged at one side of the support platform 1 under the action of a driving force. Specifically, Figure 7 and Figure 8As shown, the flip assembly 3 is a rotary cylinder, the middle part of the lifting drive structure is rotatably connected to the middle part of the rotary cylinder, a lug 20 is provided in the middle part of the support 16, a through hole is provided on the lug 20, an exposed rotating shaft is provided in the middle part of the rotary cylinder, and the rotating shaft is inserted and fixed in the through hole of the lug 20. When the lifting assembly is in the third position, the support 16 is located at the front side of the rotary cylinder along the take-off direction of the drone, and when the lifting assembly is in the second position, the support 16 is driven by the rotary cylinder to rotate to the rear side of the rotary cylinder along the take-off direction of the drone. The rotary oil cylinder includes a vertically arranged cylinder body, a rotating rod arranged inside the cylinder body, and a rotating shaft threadedly connected to the rotating rod. The rotating rod and the rotating shaft are provided with teeth meshing with each other. The axes of the rotating rod and the rotating shaft are perpendicular to each other. There is a movable space between the rotating rod and the top and bottom of the cylinder body. The upper and lower parts of the cylinder body are provided with oil inlets. By changing the pressure of the two oil inlets, the rotating rod can be raised and lowered inside the cylinder body, and then the forward and reverse rotation of the rotating shaft can be realized, thereby realizing the switching of the lifting component between the second position and the third position. Of course, the flip component 3 can also be other structures that can realize the switching of the lifting component between the second position and the third position, such as a pulley block, etc., which is not specifically limited here.

[0049] Before the UAV takes off, first, the flip assembly 3 drives the lifting assembly to flip from the third position folded on the support platform 1 to the second position set on one side of the support platform 1. Then, the slide rail 4 and the support column 5 below the slide rail 4 are manually opened in turn in the opposite direction of the folding direction of the slide rail 4, and the ends of the two adjacent slide rails 4 are overlapped and fixed by the buckle 7. At the same time, the pulley 2 is slid to the side of the mounting platform 14, and the limit plate 8 slides to the front end of the slide rail 4. Then the UAV slides onto the lifting platform 15, and the lifting drive structure drives the lifting platform 15 to rise from the second position flush with the bottom of the support platform 1 to the first position flush with the pulley 2. The UAV slides onto the pulley 2, and the pulley 2 drives the UAV forward to accelerate under the driving force provided by the first drive structure 11 until it takes off. After the UAV takes off, the second drive structure 12 drives the pulley 2 to return in the opposite direction. After the staff manually pushes the limit plate 8 back to the initial position, the slide rail 4 and the support column 5 are folded and stored on the support platform 1 in turn. After the lifting drive structure drives the lifting platform 15 to descend from the first position flush with the pulley 2 to the second position flush with the bottom of the support platform 1, the flipping assembly 3 drives the lifting assembly to rotate in the reverse direction, thereby flipping the lifting assembly to the third position folded on the support platform 1, completing a launch and reset.

[0050] A method for ejecting a medium-to-large UAV using the ejection device comprises the following steps:

[0051] The output torque of the first drive structure is increased to the rated value and maintained within the first predetermined time through the frequency converter, and the output power of the first drive structure is linearly increased from zero to the maximum power until the UAV reaches the preset speed, and the output torque of the first drive structure is reduced to zero within the second predetermined time, and the UAV takes off.

[0052] The output torque of the second drive structure is increased to the rated value within the third predetermined time by the frequency converter, and the output power of the second drive structure is linearly increased from zero to the maximum power, so as to pull the pulley back at a constant speed. Among them, the rated value of the output torque of the first drive structure is the same as the rated value of the output torque of the second drive structure, and the output power of the first drive structure is greater than the output power of the second drive structure. Specifically, the first predetermined time is 300ms, the third predetermined time is 100ms, and the output power of the first drive structure is three times the output power of the second drive structure. Under the condition that the output torque and the pulley tension of the wheel group are the same, according to P=F×v, the reset speed of the pulley is lower than the ejection speed, thereby realizing the low-speed reset of the pulley.

[0053] During the UAV launch process, the speed and overload of the UAV are collected in real time through sensors and data collectors to provide data support for the closed-loop control of the ejection process, that is, transmitted to the frequency converter, and then the output torque and output power of the first drive structure are controlled. When the speed reaches the target, the brake is controlled by the single-chip microcomputer to stop the pulley.

[0054] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A medium-to-large UAV ejection device, characterized in that: include: A supporting platform (1) is provided with a slide rail (4) suitable for the sliding of the pulley (2); A pulley (2) slidably disposed on the slide rail (4); a lifting assembly, arranged on one side of the support platform (1), comprising a lifting drive structure connected to the support platform (1) and a lifting platform (15) connected to the lifting drive structure, wherein the lifting platform (15) is adapted to be lifted to a first position flush with the pulley (2) under the action of the lifting drive structure so as to transport the drone onto the pulley (2), or to be lowered to a second position flush with the bottom of the support platform (1); A flip assembly (3) is arranged on one side of the lifting assembly. The flip assembly (3) is rotatably connected to the lifting assembly and is suitable for flipping the lifting assembly from a third position folded on the support platform (1) to a second position arranged on one side of the support platform (1) under the action of a driving force.

2. The medium-to-large UAV ejection device according to claim 1 is characterized in that: The lifting drive structure comprises a support (16) rotatably connected to the flip assembly (3) and a hydraulic cylinder (17) connected to the support (16); one end of the lifting platform (15) is connected to the piston rod of the hydraulic cylinder (17).

3. The medium-to-large UAV ejection device according to claim 2 is characterized in that: A guide rail is provided on the support column (16), and a guide block (18) which is slidably matched with the guide rail is provided at one end of the lifting platform (15).

4. The medium-to-large-sized UAV ejection device according to any one of claims 1 to 3, characterized in that: The turning component (3) is a rotary oil cylinder, and the middle part of the lifting drive structure is rotationally connected to the middle part of the rotary oil cylinder.

5. The medium-to-large UAV ejection device according to any one of claims 1 to 3, characterized in that: It also comprises a first driving structure (11) and a second driving structure (12) arranged on the supporting platform (1), wherein the first driving structure (11) drives the pulley (2) forward via a first traction member, and the second driving structure (12) drives the pulley (2) to reset via a second traction member.

6. The medium-to-large UAV ejection device according to claim 5 is characterized in that: The first drive structure (11) is a permanent magnet synchronous motor, the second drive structure (12) is a reset motor, the permanent magnet synchronous motor is connected to the pulley (2) via a wheel set, the reset motor is connected to the pulley (2) via a brake (10), and the permanent magnet synchronous motor, the reset motor and the brake (10) are all connected to a controller.

7. The medium-to-large UAV ejection device according to any one of claims 1 to 3, characterized in that: The slide rail (4) comprises a plurality of sections connected in a folding manner. Two adjacent sections of the slide rail (4) are connected by a pin shaft (6) when in a folded state, and are locked and fixed by a buckle (7) when unfolded.

8. The medium-to-large UAV ejection device according to any one of claims 1 to 3, characterized in that: The supporting platform (1) is a vehicle-mounted chassis.

9. A method for launching a medium-to-large-sized UAV using the launching device of any one of claims 1 to 8, characterized in that: The following steps are involved: The output torque of the first drive structure is increased to a rated value and maintained within a first predetermined time, and the output power of the first drive structure is increased to a maximum power until the UAV reaches a preset speed, and the output torque of the first drive structure is reduced to zero within a second predetermined time, and the UAV takes off; The output torque of the second drive structure is increased to the rated value within the third predetermined time, and the output power of the second drive structure is increased to the maximum power, and the pulley is pulled back at a constant speed at a constant speed: The rated value of the output torque of the first drive structure is the same as the rated value of the output torque of the second drive structure, and the output power of the first drive structure is greater than the output power of the second drive structure.

10. The ejection method according to claim 9, characterized in that: The first predetermined time is 300 ms, the third predetermined time is 100 ms, and the output power of the first driving structure is three times the output power of the second driving structure.

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