Lightweight 4D millimeter wave radar device and unmanned aerial vehicle

Abstract

The invention belongs to the technical field of millimeter-wave radars, and particularly relates to a lightweight 4D millimeter-wave radar device and an unmanned aerial vehicle, the lightweight 4D millimeter-wave radar device comprises a digital circuit board, a radio frequency circuit board and a mask, and further comprises a main support, the main support comprises a mask frame and a stand column, the mask is installed on one side of the mask frame, and the stand column is installed on the other side of the mask frame; mounting holes are formed in the digital circuit board and the radio frequency circuit board, and the digital circuit board and the radio frequency circuit board are mounted on the stand columns through the mounting holes; the heat dissipation mechanism comprises a heat dissipation plate, a guide pipe, a vibration exciter and a flexible liquid storage bag, the vibration exciter is installed on the liquid storage bag, the liquid storage bag is installed between the digital circuit board and the radio frequency circuit board, the edge of the liquid storage bag is connected with the stand columns, the heat dissipation plate is installed on the periphery of the mask frame, and the liquid storage bag is used for storing cooling liquid; the guide pipe is used for establishing a cooling liquid circulation loop between the liquid storage bag and the heat dissipation plate. According to the invention, the light weight of the 4D millimeter wave radar is realized, and the good heat dissipation performance is ensured.

Description

Technical Field

[0001] The present invention belongs to the technical field of millimeter wave radars, and in particular relates to a lightweight 4D millimeter wave radar device and an unmanned aerial vehicle. Background Art

[0002] Commonly used 4D millimeter wave radars include a metal heat sink base, on which the digital circuit board is fastened with screws; the circuit components on the digital circuit board are mounted on one side of the shielding plate, and the RF circuit board is mounted on the other side of the shielding plate; the mask is snapped onto the metal heat sink base, and the mask covers the digital circuit board, shielding plate, and RF circuit board. As the market's demand for 4D millimeter wave radar point cloud quantity, distance accuracy, speed measurement accuracy, angular resolution, penetration, and other performance requirements increase, 4D millimeter wave radars require more RF antennas and exponentially growing computing power, and the heat generated on the RF circuit board and digital circuit board has also increased significantly.

[0003] Commonly used 4D millimeter wave radars are mostly used in cars. Compared with the weight of tons of vehicles, the weight of 4D millimeter wave radars themselves usually does not need to be considered too much, so water cooling or a large number of cooling fins can be used for heat dissipation. The overall structure size is relatively large, and the overall mass is also relatively large, weighing from a few hundred grams to kilograms. However, when 4D millimeter wave radars are applied to drones that are more sensitive to the weight of components, and even when multiple 4D millimeter wave radars need to be installed on drones, the existing 4D millimeter wave radar structure is obviously not suitable for the needs of drones. Therefore, it is necessary to lighten the 4D millimeter wave radar and also ensure good heat dissipation performance. Summary of the invention

[0004] The present invention is intended to provide a lightweight 4D millimeter-wave radar device and an unmanned aerial vehicle, so as to make the 4D millimeter-wave radar lighter while ensuring good heat dissipation performance.

[0005] In order to achieve the above object, the scheme of the present invention is: a lightweight 4D millimeter wave radar device, including a digital circuit board, a radio frequency circuit board, a mask, and also includes:

[0006] The main bracket includes a mask frame and a column, the mask is installed on one side of the mask frame, and the column is installed on the other side of the mask frame; both the digital circuit board and the radio frequency circuit board are provided with mounting holes, and the digital circuit board and the radio frequency circuit board are mounted on the column through the mounting holes;

[0007] The heat dissipation mechanism includes a heat sink, a duct, an exciter and a flexible liquid storage bag. The exciter is installed on the liquid storage bag, the liquid storage bag is installed between the digital circuit board and the radio frequency circuit board, the edge of the liquid storage bag is connected to the column, the heat sink is installed around the mask frame, the liquid storage bag is used to store coolant, and the duct is used to establish a circulation loop of coolant between the liquid storage bag and the heat sink.

[0008] The working principle and beneficial effects of this solution are:

[0009] 1. This solution ensures that the original radar function of the 4D millimeter-wave radar is not affected, while allowing the 4D millimeter-wave radar to abandon the metal heat dissipation base in the traditional design, and also abandons various connecting and fastening parts in the traditional design, thereby reducing the weight by more than 50%, truly realizing the lightweight of the 4D millimeter-wave radar.

[0010] 2. This solution innovatively places the heat sink used to dissipate heat as close to the mask as possible, and combined with the overall compact structural design of this solution, the 4D millimeter-wave radar in this solution can be directly installed on the outer surface of the drone shell, or integrated with the outer surface, so that the airflow generated by the propeller when the drone is working can be fully utilized to naturally and efficiently take away the heat on the heat sink, thereby efficiently dissipating heat.

[0011] 3. The installation position and structural design of the heat dissipation mechanism in this scheme can make full use of the inertia of the UAV during maneuvers, so that the exciter can compress the flexible liquid storage bag under the action of inertia at each acceleration change during the UAV maneuvers, so that the coolant is constantly agitated, thereby allowing the coolant to circulate in the circulation loop. Thanks to the liquid storage bag being able to face the digital circuit board and the RF circuit board at the same time, the heat on the digital circuit board and the RF circuit board that generate the most heat can be directly and efficiently taken to the heat sink for dissipation during the flow process.

[0012] 4. While ensuring good heat dissipation performance, the entire heat dissipation mechanism is conducive to flat design. Compared with the heavy design of traditional 4D millimeter-wave radar, this solution can greatly reduce the structural size of the 4D millimeter-wave radar, especially the size in the thickness direction can be greatly reduced, which is very suitable for the needs of application scenarios such as drones with small and compact space inside the body.

[0013] Optionally, the liquid storage bag includes at least two layers of bags, the exciter is arranged between the bags, and the coolant is stored in the bags. When the exciter vibrates, it can oscillate the bags on both sides at the same time, so that the coolant in the bags flows more frequently, and the heat dissipation effect is better. In addition, the bags can be used to isolate and buffer the exciter, so as to prevent the digital circuit board and the radio frequency circuit board on both sides from being damaged when the exciter vibrates, and avoid increasing the structural size of the 4D millimeter wave radar in the thickness direction.

[0014] Optionally, the exciter includes at least two exciter arms, the exciter arms are connected to the middle of the liquid storage capsule, and the ends of the exciter arms away from the liquid storage capsule are free ends and are provided with counterweights. By utilizing the lever principle, the vibration amplitude of the exciter is increased, so that the flow rate and pressure of the coolant in the circulation loop are greater, further improving the heat dissipation effect.

[0015] Optionally, the vibrator further includes an active excitation module, the active excitation module includes an excited part and an exciting part, the exciting part excites the excited part to generate vibration, the excited part is mounted on the liquid storage capsule, and the exciting part is mounted on a digital circuit board, a radio frequency circuit board, a mask frame or a column. When the drone is in a constant speed cruise flight or the heat dissipation performance needs to be enhanced, the vibration excitation module is started to actively excite the vibrator to generate vibration.

[0016] Optionally, the active excitation module includes a permanent magnet and a magnetic induction coil, the permanent magnet is mounted on the liquid storage capsule, and the magnetic induction coil is powered and controlled by a digital circuit board. The digital circuit board controls the power supply to the magnetic induction coil and changes the polarity of the power supply, so that the magnetic induction coil generates a constantly changing magnetic pole, thereby causing the permanent magnet to vibrate.

[0017] Optionally, the active excitation module includes a crank mechanism, which is mounted on a column and driven by a micro motor, the crank mechanism is connected to an excitation arm, and the micro motor is powered and controlled by a digital circuit board.

[0018] Optionally, the number of heat sinks is two pairs, the mask frame is a polygon with four or more sides, the heat sinks are installed around the mask frame, the two sides of the same layer of bags are connected to the same pair of heat sinks through conduits, and the same pair of heat sinks are connected through conduits. Each layer of bags supplies coolant to a pair of heat sinks facing each other, so as to form two independent circulation loops and facilitate the flow of coolant in the circulation loops, and also utilize inertia in more directions.

[0019] Optionally, a bottom shell is also included. After the bottom shell is installed on the main bracket, the digital circuit board, the radio frequency circuit board, the column and the liquid storage capsule are all covered in the bottom shell, and the inner wall or the outer wall of the bottom shell is covered with a metal shielding layer.

[0020] Optionally, a one-way valve mechanism is provided in the circulation loop, so that the coolant can only flow in one direction in the circulation loop, thereby achieving a better heat dissipation effect.

[0021] Another aspect of the present invention is to provide an unmanned aerial vehicle, on which the aforementioned 4D millimeter wave radar device is installed. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the structure of a lightweight 4D millimeter wave radar device in an embodiment of the present invention;

[0023] Figure 2 It is a structural schematic diagram of the heat dissipation mechanism in an embodiment of the present invention;

[0024] Figure 3 It is a side view of the heat dissipation mechanism in the embodiment of the present invention. DETAILED DESCRIPTION

[0025] The following is further described in detail through specific implementation methods:

[0026] The marks in the drawings of the specification include: digital circuit board 1, radio frequency circuit board 2, mask frame 3, column 4, stud 401, gasket 402, heat dissipation mechanism 5, heat dissipation plate 501, bag 502, fixing ring 503, permanent magnet 504, excitation arm 6, counterweight 7, and one-way valve 8.

[0027] Example

[0028] This embodiment is basically Figure 1 As shown: a lightweight 4D millimeter wave radar device and a UAV, wherein the UAV is composed of a fuselage and a plurality of rotors mounted on the fuselage, and a plurality of 4D millimeter wave radar devices are mounted around the fuselage, and the 4D millimeter wave radar device includes a digital circuit board 1, a radio frequency circuit board 2, and a mask (not shown in the drawings), and also includes:

[0029] The mask is an octagonal thin-walled part made of plastic, nylon, carbon fiber, and other materials that do not block millimeter waves. The outer shell of the fuselage is made of metal, and a radar hole is opened on the fuselage to match the mask. The mask is installed in the radar hole, and the outer surface of the mask is flush with the outer surface of the fuselage.

[0030] The main bracket includes a mask frame 3 and a column 4. The mask frame 3 and the column 4 are both made of light alloy (aluminum alloy, aluminum-magnesium alloy, etc.), wherein the mask frame 3 is a quadrilateral frame corresponding to the shape of the mask. The mask is installed on one side of the mask frame 3, and the column 4 is installed on the other side of the mask frame 3. There are four columns 4, each of which is divided into three sections. One end of each section of the column 4 is a stud 401 and the other end is a threaded hole matching the stud 401. The four corners of the mask frame 3 are also provided with threaded holes matching the stud 401. The diameter of the stud 401 is smaller than the diameter of the column 4, thereby forming a boss between the stud 401 of each section of the column 4 and the body of the column 4. Both the digital circuit board 1 and the radio frequency circuit board 2 are provided with mounting holes, and the mounting holes are located at the four corners of the digital circuit board 1 and the radio frequency circuit board 2. The digital circuit board 1 and the radio frequency circuit board 2 are mounted on the column 4 through the mounting holes. More specifically: the mounting holes are through holes reserved on the circuit board. The studs 401 of one section of the column 4 pass through the mounting holes and are screwed into the threaded holes of another section of the column 4. The bosses of one section of the column 4 and the corresponding gaskets 402 are used to press it onto the other section of the column 4, so that the four corners of the digital circuit board 1 and the radio frequency circuit board 2 are fixed to the column 4, and the digital circuit board 1 and the radio frequency circuit board 2 can be kept parallel to each other. The space between the digital circuit board 1 and the radio frequency circuit board 2 is used to place the heat dissipation mechanism 5.

[0031] Heat dissipation mechanism 5, as attached Figure 2 and attached Figure 3 As shown, the heat dissipation mechanism 5 includes a heat sink 501, a conduit, an exciter and a flexible liquid storage bag, wherein the heat sink 501 is four hollow cavities made of light alloy material, which are in a cubic shape as a whole and are distributed on the four sides of the mask frame 3 by bonding. Each pair of heat sinks 501 is connected in series through a conduit. When the 4D millimeter-wave radar device is installed on the body, the heat sink 501 is close to the inner side of the outer shell of the body, and thermal conductive silicone is coated between the heat sink 501 and the inner surface of the outer shell. The outer shell of the body is used to dissipate heat, and the airflow generated by the propeller and the extensionless flight takes away the heat emitted by the 4D millimeter-wave radar device.

[0032] The liquid storage bag includes two layers of bags 502, the vibrator is arranged between the bags 502, and the coolant is stored in the bags 502. The bags 502 are made of heat-conductive, corrosion-resistant, high-temperature-resistant, flexible, and impermeable films or cloths, such as graphite nylon cloth made of nylon 6, graphite oxide, polyvinyl chloride, etc., 1680D nylon cloth, or metal sheets made of nickel-based alloys, etc. In this embodiment, it is graphite nylon cloth. Each layer of the bag 502 is formed by sealing the edges of two layers of the above materials and is rectangular. Fixed rings 503 are also fixed on the four corners of the bag 502, which are respectively fixed to the four pillars 4 in the same way as the digital circuit board 1. Interfaces are left on both sides of the bag 502. After the coolant is filled into the bag 502, the bag 502 bulges, that is, the thickness in the middle of the bag 502 is higher than the thickness around it, thereby leaving vibration space for the vibrator. The middle part of the bulged bag 502 fits with the digital circuit board 1 and the radio frequency circuit board 2. Even when the exciter vibrates the liquid storage bag, the two can maintain contact and transfer heat. More importantly, it will not cause impact on the two circuit boards, avoiding damage to the two circuit boards.

[0033] In this embodiment, the coolant is an ethylene glycol-based coolant, which has excellent thermal conductivity, and because it is non-metallic, it does not hinder the passage of magnetic flux lines, and can be used in conjunction with an electromagnetic induction active excitation module. However, in order to avoid possible signal interference between the digital circuit board 1 and the radio frequency circuit board 2, a metal film is plated in a layer of the bag 502 close to the radio frequency circuit board 2 or a metal interlayer is added to form a shielding layer between the digital circuit board 1 and the radio frequency circuit board 2. In other embodiments, if the coolant is a liquid metal, such as a gallium-based liquid alloy, the coolant can be directly used to form a shielding layer, and the active excitation module needs to be used in conjunction with a mechanical structure excitation method. The electromagnetic induction active excitation module used in this embodiment includes a permanent magnet 504 and a magnetic induction coil. The permanent magnet 504 is installed on the liquid storage capsule. Specifically, the permanent magnet 504 is a coin-sized magnetic block, which is bonded between the two bags 502 by bonding. A support frame is integrally formed on the four sections of the column 4 in the middle by 3D printing, and the magnetic induction coil is installed on the support frame. The magnetic induction coil is powered and controlled by the digital circuit board 1. Each layer of bag 502 is connected in series with a pair of adjacent heat sinks 501. The adjacent heat sinks 501, their conduits, and their bag 502 form a cooling liquid circulation loop, with two sets of circulation loops in total. A one-way valve 8 is installed on the conduit of each loop, and the one-way valve 8 is set between the two heat sinks 501.

[0034] In this embodiment, the exciter includes four excitation arms 6, which are arranged in a cross shape, one end of the excitation arm 6 is fixed to the permanent magnet 504, and the end of the excitation arm 6 away from the permanent magnet 504 is a free end and is provided with a counterweight 7. By using the lever principle, the vibration amplitude of the exciter is increased, so that the flow rate and pressure of the coolant in the circulation loop are greater, and the heat dissipation effect is further improved.

[0035] In another embodiment, a bottom shell is also included, which is made of plastic. After the bottom shell is installed on the main bracket, the digital circuit board 1, the radio frequency circuit board 2, the column 4 and the liquid storage capsule are all covered in the bottom shell, and a metal shielding layer is electroplated on the inner wall of the bottom shell, which is a copper layer in this embodiment. The metal shielding layer in the bottom shell is used to prevent the 4D millimeter wave radar device from interfering with the electronic devices in the machine body.

[0036] This embodiment can utilize the inertia of the drone during maneuvers, so that the exciter, under the action of inertia, presses the flexible liquid storage bag at each acceleration change during the maneuvers of the drone, so that the coolant is constantly agitated, so that the coolant circulates in one direction in the circulation loop, and in the process of flowing, directly and efficiently takes the heat on the digital circuit board 1 and the radio frequency circuit board 2 that generate the most heat to the heat sink 501 for dissipation. When the drone is cruising at a constant speed or the heat dissipation performance needs to be enhanced, the permanent magnet 504 on the exciter is excited to vibrate through the magnetic induction coil, so as to actively make the coolant in the circulation loop flow, thereby achieving a good cooling effect.

[0037] The above are only embodiments of the present invention. The invention is not limited to the fields involved in this implementation case. For those skilled in the art, several modifications and improvements can be made without departing from the structure of the present invention. These should also be regarded as the protection scope of the present invention. These will not affect the effect of the implementation of the present invention and the practicality of the patent. The protection scope required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A lightweight 4D millimeter wave radar device, characterized in that: Includes digital circuit board, RF circuit board, mask, and also includes: The main bracket includes a mask frame and a column, the mask is installed on one side of the mask frame, and the column is installed on the other side of the mask frame; both the digital circuit board and the radio frequency circuit board are provided with mounting holes, and the digital circuit board and the radio frequency circuit board are mounted on the column through the mounting holes; The heat dissipation mechanism includes a heat sink, a duct, an exciter and a flexible liquid storage bag. The exciter is installed on the liquid storage bag, the liquid storage bag is installed between the digital circuit board and the radio frequency circuit board, the edge of the liquid storage bag is connected to the column, the heat sink is installed around the mask frame, the liquid storage bag is used to store coolant, and the duct is used to establish a circulation loop of coolant between the liquid storage bag and the heat sink.

2. The lightweight 4D millimeter wave radar device according to claim 1, characterized in that: The liquid storage bag comprises at least two layers of bags, the vibrator is arranged between the bags, and the cooling liquid is stored in the bags.

3. The lightweight 4D millimeter wave radar device according to claim 2, characterized in that: The vibrator comprises at least two vibrating arms, which are connected to the middle of the liquid storage capsule. The ends of the vibrating arms away from the liquid storage capsule are free ends and are provided with counterweights.

4. The lightweight 4D millimeter wave radar device according to claim 3, characterized in that: The exciter also includes an active excitation module, which includes an excited part and an exciting part. The exciting part excites the excited part to generate vibration. The excited part is installed on the liquid storage bag, and the exciting part is installed on the digital circuit board, the radio frequency circuit board, the mask frame or the column.

5. The lightweight 4D millimeter wave radar device according to claim 4, characterized in that: The active excitation module includes a permanent magnet and a magnetic induction coil. The permanent magnet is installed on the liquid storage capsule, and the magnetic induction coil is powered and controlled by a digital circuit board.

6. The lightweight 4D millimeter wave radar device according to claim 4, characterized in that: The active excitation module comprises a crank mechanism, which is mounted on a column and driven by a micro motor, the crank mechanism is connected to an excitation arm, and the micro motor is powered and controlled by a digital circuit board.

7. The lightweight 4D millimeter wave radar device according to claim 5, characterized in that: There are two pairs of heat sinks, the mask frame is a polygon with four sides or more, the heat sinks are installed around the mask frame, the two sides of the same layer of bag are connected to the same pair of heat sinks through catheters, and the same pair of heat sinks are connected through catheters.

8. The lightweight 4D millimeter wave radar device according to claim 1, characterized in that: It also includes a bottom shell. After the bottom shell is installed on the main bracket, the digital circuit board, the radio frequency circuit board, the column and the liquid storage capsule are all covered in the bottom shell, and the inner wall or the outer wall of the bottom shell is covered with a metal shielding layer.

9. The lightweight 4D millimeter wave radar device according to claim 1, characterized in that: A one-way valve mechanism is provided in the circulation loop.

10. An unmanned aerial vehicle, characterized in that: The 4D millimeter wave radar device according to any one of claims 1 to 9 is mounted on a body of the drone.

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