CN113495358A

CN113495358A - Laser scanning device and laser radar comprising same

Info

Publication number: CN113495358A
Application number: CN202010249395.4A
Authority: CN
Inventors: 申士林; 向少卿
Original assignee: Hesai Technology Co Ltd
Current assignee: Hesai Technology Co Ltd
Priority date: 2020-04-02
Filing date: 2020-04-02
Publication date: 2021-10-12

Abstract

The present disclosure provides a laser scanning device, including a coil and a sealing film; the coil is wound by electromagnetic wires; the coil is coated by the sealing film and used for sealing the coil, and two ends of the electromagnetic wire extend out of the sealing film, so that paint on the coil can be prevented from volatilizing by arranging the sealing film for coating the coil on the coil, and the outgoing window fuzziness caused by volatilization of the paint can be reduced, thereby reducing the instability of the light paths of the detection light beam and the receiving light beam, and improving the accuracy of the laser scanning device. Moreover, the aging of devices caused by paint volatilization can be slowed down, and the service life of the laser scanning device is prolonged.

Description

Laser scanning device and laser radar comprising same

Technical Field

The present disclosure relates to the field of laser detection technologies, and in particular, to a laser scanning device and a laser radar including the laser scanning device.

Background

This section provides background information related to the present disclosure, which does not necessarily constitute prior art.

In the automatic driving technology, an environment sensing system is a basic and crucial ring and is a guarantee for the safety and intelligence of an automatic driving automobile, and a laser radar in an environment sensing sensor has incomparable advantages in the aspects of reliability, detection range, distance measurement precision and the like. The laser radar analyzes the turn-back time of the laser after encountering the target object by transmitting and receiving the laser beam, and calculates the relative distance between the target object and the vehicle.

With the continuous advance of the automatic driving technology, the scanning mirror type lidar is regarded as an important technical route in the solid state lidar scheme, and a reflecting device (a vibrating mirror) which can rotate, vibrate or deflect reflects the light of a laser, so that scanning is realized. The laser scanning device is an important component of the laser radar, but in the working process, the temperature of the laser scanning device is increased due to the rotation, vibration or deflection mechanical movement of a galvanometer, or the fact that a coil is electrified to generate heat, and stray light is absorbed, and further the physical or chemical properties of some parts on the laser scanning device are unstable. For example, the insulating varnish on the surface of the coil is aged by heat, so that the insulating and moisture-resistant effects are reduced; even at high temperature, the insulating paint may be carbonized and volatilized, and is deposited on a photomask window, so that the window is blurred, the detection light beam is prevented from transmitting, and the radar detection accuracy is reduced.

Disclosure of Invention

The present disclosure provides a laser scanning apparatus and a laser radar including the same.

In a first aspect, embodiments of the present application provide a laser scanning device, a coil, and a sealing film; the coil is wound by electromagnetic wires; the sealing film is used for coating the coil and sealing the coil, and two ends of the electromagnetic wire extend out of the sealing film.

In some embodiments, the sealing film comprises a first sub-film and a second sub-film, wherein the first sub-film and the second sub-film are integrated to form the sealing film.

In some embodiments, an electromagnetic wire hole is disposed between the first sub-film and the second sub-film.

In some embodiments, the outer skin layer of the sealing film is black in color.

In some embodiments, the sealing film has a thickness of less than 100 microns.

In some embodiments, the material of the sealing film comprises polyetherimide.

In some embodiments, the sealing membrane is formed by injection molding.

In some embodiments, the sealing membrane is formed by split injection molding.

In some embodiments, the sealing film is formed by plating.

In a second aspect, an embodiment of the present application provides a laser radar, including the laser scanning apparatus according to any one of the first aspects.

Therefore, according to the laser scanning device and the laser radar comprising the laser scanning device, the coil is provided with the sealing film for coating the coil, so that the paint on the coil can be prevented from aging and falling off, the reduction of coil insulativity and moisture resistance caused by paint aging can be reduced, and the service life of the laser scanning device is prolonged; on the other hand, the blurring of the exit window caused by the volatilization of the paint at high temperature can be avoided, so that the instability of the light paths of the detection light beam and the receiving light beam is reduced, and the accuracy of the laser detection of the laser scanning device is improved.

Drawings

The foregoing and additional features and characteristics of the present disclosure will be better understood from the following detailed description, taken with reference to the accompanying drawings, which are given by way of example only and which are not necessarily drawn to scale. Like reference numerals are used to indicate like parts in the accompanying drawings, in which:

FIG. 1 shows a schematic diagram of a lidar in accordance with an embodiment of the disclosure;

fig. 2 shows a schematic structural diagram of a laser scanning device in an embodiment in accordance with the present disclosure;

FIG. 3 shows a schematic structural diagram of a reflective device in an embodiment in accordance with the present disclosure;

fig. 4 shows a schematic structural view of a coil and a sealing film according to the present disclosure.

Detailed Description

Preferred embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses.

In the description of the present disclosure, it is to be understood that the terms "upper", "lower", "top", "bottom", and the like, indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are only for convenience in describing the present disclosure and simplifying the description, and do not indicate or imply that the referred devices or elements must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present disclosure. Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. Moreover, the terms "first," "second," and the like are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the disclosure described herein are capable of operation in sequences other than those illustrated or otherwise described herein.

Embodiments of the present disclosure provide a laser scanning device including a coil and a sealing film.

In some application scenarios, please refer to fig. 1, the laser scanning apparatus can be applied to a solid-state lidar.

Fig. 1 shows a schematic structural diagram of a lidar in an embodiment in accordance with the disclosure. Here, as shown in fig. 1, the laser radar may generally include a light splitting assembly 11, a laser scanning device 12, and a receiving assembly 13. The beam splitting section 11 is for splitting the pulse laser beam for detection into a plurality of incident beams. And transmits the incident beam to the laser scanning device 12. The number of incident light beams here may be 2 or more. The pulse laser beam for detection is split into a plurality of incident lights using the beam splitting assembly 11, so that the number of pulse laser beams can be increased. The volume of the laser radar can be reduced, and the heat generated during the operation of the laser radar can be reduced. The laser scanning device 12 is configured to reflect a plurality of incident beams incident thereon into a space outside the laser radar, and is configured to receive a plurality of echo beams after the plurality of incident beams are reflected by an object to be measured in the space outside the laser radar. The receiving assembly 13 may be configured to receive and process the multiple echo beams.

In some application scenarios, the light splitting element may include a first light splitting element 112 and a second light splitting element 113 disposed between the deflection element 111 and the first reflection element 114. The first light splitting element 112 is adjacent to the deflecting element 111. The pulsed laser beam after being deflected by the deflecting element 111 is incident on the first light splitting element 112. The first light splitting element 112 may transmit a portion of the pulsed laser beam into the second light splitting element 112. The first beam splitting element 112 may also reflect a portion of the pulsed laser beam onto the laser scanning device 12. The second light splitting element 123 may transmit a portion of the pulse laser beam incident thereto to the first reflecting element 114 and reflect a portion of the pulse laser beam incident thereto onto the laser scanning device 12. The first reflecting element 114 may reflect a part of the pulse laser beam transmitted through the second light splitting element 113 to the above-described laser scanning device 12.

In some application scenarios, the laser scanning device, which may also be referred to as a galvanometer, may include a fixed portion 122 and a movable portion 121, and the movable portion 121 may rotate, and may also perform a vibrating or deflecting motion. One surface of the movable portion 121 may be a mirror that reflects an incident light beam incident thereto and reflects an echo light beam incident thereto.

In some application scenarios, the movable portion 121 may be reciprocally deflectable about its horizontal and vertical axes. The pulse laser beam emitted by the laser source can be divided into a plurality of incident beams by the light splitting component. The angle of incidence of different beams of light to the reflecting mirror is adjusted by setting the reflection angle of each element of the light splitting assembly to the pulse laser beam incident to the element, and the angle of incidence of each beam of incident light to the space is adjusted by deflecting the reflecting mirror. Multiple incident beams can be incident into the target space at different field angles, and scanning of multiple scanning fields can be achieved.

Fig. 2 shows a schematic structural diagram of a laser scanning device according to an embodiment of the present disclosure. Referring to fig. 2, the movable portion 121 of the galvanometer (i.e., the laser scanning device 12) may include a substrate 20, which may be fixedly connected to the fixed portion 122. Specifically, the galvanometer comprises an upper magnet fixing component, a substrate, a circuit board and a lower magnet fixing component which are sequentially connected, wherein an upper magnet is arranged inside the upper magnet fixing component, and a lower magnet is arranged inside the lower magnet fixing component. The above parts are connected in sequence to form a vibrating mirror, and then fixedly connected with the fixing part 122.

In some embodiments, the base plate may include a first torsion shaft 202, the movable member 201 is connected with the base plate 20 by the first torsion shaft 202, and the movable member 201 is capable of a first deflection motion about the first torsion shaft 202. Preferably, the movable member 201 is located in the same plane as the substrate 20 when located at the initial position. The reflecting means 204, e.g. a mirror, is fixed to a fixed member (not shown in the figures) which is connected to the movable member 201 by a second torsion axis 205, and the second torsion axis 205 is at an angle to the first torsion axis 202, preferably, in this embodiment, the second torsion axis 205 is at a right angle to the first torsion axis 202. Thus, when the movable member 201 performs a first deflection movement about the first torsion axis 202, the reflection device 204 is capable of performing the first deflection movement about the first torsion axis 202 along with the movable member 201, and the reflection device 204 is also capable of performing a second deflection movement about the second torsion axis 205 relative to the movable member 201. In this way, the reflection means 204 can perform a yaw movement in two mutually perpendicular degrees of freedom.

In some embodiments, the movement rate of the second deflection movement of the reflecting device 204 about the second torsion axis 205 may be higher than the vibration frequency of the movable member 201 about the first torsion axis 202 for the first deflection movement.

In this embodiment, a control module (not shown) may also be used to control and regulate the movement of the reflecting device including the reflecting device 204 and the movable member 201. In particular, the control module monitors the light intensity of the light beam reflected by the reflection device 204 detected by the detection module in real time, and when the light intensity of the light beam reflected by the reflection device 204 detected by the detection module is less than or equal to a preset value, the control module controls the amplitude, speed, and the like of the first deflection motion and the second deflection motion of the reflection device, thereby protecting the laser scanning device and the laser radar. Preferably, in an exemplary embodiment of the present disclosure, the control module controls the movement of the reflection device by adjusting a driving power for driving the reflection device to perform the first and second deflection movements, for example, preferably, when the light intensity of the light beam (or the light spot) reflected by the reflection device 204 and impinging on the position sensor, which is detected by the detection module, is equal to the preset value, the control module controls the driving power to be set to zero, so that the movement of the reflection device is stopped.

In some application scenarios, as shown in fig. 3, the galvanometer includes a coil 2011, which in this embodiment is fixed to the movable member 201. The coil is electrically connected with a circuit board, and the circuit board is connected with an alternating current circuit to the coil. The alternating current in the coil, under the action of the magnetic field between the upper and lower magnets, generates a driving force on the reflection device 204 to drive it to deflect around the torsion axis.

In this embodiment, the coil is wound from electromagnetic wire.

In this embodiment, the reflection unit may further include a sealing film 2012 covering the coil to seal the coil, and both ends of the magnet wire may protrude from the sealing film.

Referring to fig. 4, a schematic diagram of a coil 2011 and a sealing film 2012 is shown. In fig. 4, for convenience of illustration, the seal film and the coil are illustrated as an exploded view; in fact, the sealing film is coated on the surface of the coil, and the coated coil cannot leak out of the sealing film. And, the sealing film is shown in two parts; in practice, the sealing film is what can be considered as a whole, rather than wrapping several parts of the coil.

In this embodiment, the magnet wire may be an insulated wire that generates a magnetic field when energized or induces a current in a magnetic field. Magnet wires are used primarily in motor and transformer windings and other related electromagnetic equipment. The conductors of the magnet wire comprise copper wire, which is coated with a thin insulating layer. The conductor of the electromagnetic wire is also called a wire core, and can be divided into a hard type, a soft type, a movable type and an ultra-soft type according to the use requirement. The wire cores are four types, namely a single core, a two-core, a three-core and a four-core. The insulating layer is generally made of rubber, plastic or the like. Such insulated wires are widely used for various instruments and meters, telecommunication equipment, power lines and lighting lines having an ac voltage of 500 v or less and a dc voltage of 2000 v or less. Therefore, electromagnetic wires generally have good electromechanical properties, as well as heat, moisture, and solvent resistance. Different insulating materials are selected to achieve different characteristics.

In practice, electromagnetic wires mainly comprise enameled wires and lapped wires. The enameled wire is made by coating insulating paint on a bare copper wire, has a thin insulating layer and small occupied volume, and is widely applied to various electric machines, electric appliances, instruments and meters. The properties of the enamel wire vary depending on the nature of the insulating material used. The lapping wire mainly comprises a yarn-covered wire, a silk-covered wire, a glass silk-covered wire, a paper-covered wire, a plastic film-covered wire and the like.

In the prior art, in laser scanning devices for laser radar, electromagnetic wires in the form of enameled wires are generally used. The insulating paint is generally made of high molecular polymer, is unstable at high temperature, and the maximum allowable working temperature of the insulating paint is generally not more than 200 ℃. In a coil formed by winding an enameled wire, insulating paint coated on an electromagnetic wire is easy to age and fall off because the coil is heated and heated due to reasons of heating, stray light absorption and the like when being electrified, and the insulativity and the moisture resistance of the coil are reduced. When the temperature exceeds the heat resistance threshold of the insulating varnish, the high molecular polymer may decompose into carbon or hydrogen-containing compounds. The decomposed substance is deposited on the exit window (for light exit) of the laser scanning device mask, and the penetration of the detection beam or the echo beam is influenced, so that the detection accuracy is reduced.

It should be noted that, the sealing film for coating the coil is adopted in the laser scanning device, so that the paint on the coil can be prevented from falling off or decomposing and volatilizing, the service life of the laser scanning device can be prolonged, and the blurring of a photomask window caused by the volatilization and deposition of the paint can be reduced, thereby reducing the instability of the light paths of the detection light beam and the receiving light beam and improving the accuracy of the laser scanning device. Laser scanning device

In some embodiments, referring to fig. 4, the sealing film 2012 includes a first sub-film 20121 and a second sub-film 20122. Here, the first sub-film and the second sub-film are integrated to form the sealing film.

Here, the sealing film is divided into the first sub-film and the second sub-film, so that the manufacturing cost can be reduced. When the sealing film is manufactured, a first sub-film and a second sub-film can be manufactured respectively; then, the first sub-film and the second sub-film sleeved on the coil can be naturally fused when the temperature is higher than a preset temperature threshold value.

In some embodiments, an electromagnetic wire hole is disposed between the first sub-film and the second sub-film. The electromagnetic wire hole is used for allowing two ends of the electromagnetic wire to extend out of the sealing film.

Here, both ends of the magnet wire may be drawn out before the first and second sub-films are fused. So that both ends of the magnet wire protrude from the sealing film after the first and second sub-films are fused.

In some embodiments, the color of the sealing film may be set according to practical situations, and is not limited herein.

The use of a black outer layer for the sealing film reduces the reflection of light, thereby reducing the interference of the reflected light from the sealing film with the reflected light from the mirror and improving the accuracy of the laser scanner.

In some embodiments, the thickness of the sealing film may be set according to practical situations, and is not limited herein.

In some embodiments, the sealing film has a thickness of less than 100 microns.

The thickness of the sealing film is less than 100 microns, so that the volume occupied by the sealing film can be reduced, the sealing effect of the sealing film on the coil is ensured, and the volume of the whole laser scanning device is not enlarged by the sealing film.

In some embodiments, the material of the sealing film may be selected according to actual needs, and is not limited herein. The sealing film should have good thermal conductivity to avoid raising the working temperature of the insulating varnish due to sealing.

As an example, the material of the sealing film may include, but is not limited to, at least one of the following: polyetherimides, polybutylene terephthalate, polycarbonates, and the like.

In some embodiments, the material of the sealing film comprises polyetherimide.

Here, Polyetherimide (PEI) may be a super engineering plastic manufactured from amorphous Polyetherimide.

It should be noted that the use of PEI as a sealing film for the coil in the galvanometer ensures that stable chemical properties (e.g., non-volatility) and physical properties (e.g., non-deformation) are maintained at higher temperatures during operation of the laser scanning apparatus.

Here, the sealing film may be injection molded. The injection molding process is generally as follows: the plastic is heated to a certain temperature and then melted into liquid, the melted liquid is injected into a sealed die cavity by an injection molding machine under high pressure, and the required plastic product is obtained after the die is cooled and oriented and is ejected after the die is opened.

In the process of injection molding, a plastic mold, an injection molding machine, plastic raw materials and the like are needed. The injection molding machine adopts different division bases and can be divided into a plurality of types. For example, injection methods can be classified into: horizontal injection molding machines, vertical injection molding machines, angle injection molding machines, multicolor injection molding machines; according to the mode locking method, the method can be divided into: direct-pressure injection molding machines, crankshaft injection molding machines, direct-pressure, crankshaft compound type injection molding machines, and the like.

In some embodiments, the specific process of injection molding is not limited. The skilled in the art can select various injection molding modes according to practical application scenarios.

In some embodiments, the sealing membrane is formed by integral injection molding.

The integral injection molding may mean that the sealing film is integrally molded by injection molding.

In some embodiments, the sealing membrane is formed by split injection molding.

The split injection molding can mean that the whole sealing film can be divided into a plurality of parts, and a plurality of sub-sealing films are obtained through injection molding of each part; and then combining the plurality of sub-sealing films into a complete sealing film.

In some application scenarios, the manner of dividing the sub-sealing film can be determined according to the difficulty level of the injection molding process. For example, the sealing film is split into two sub-sealing films in a mode of being perpendicular to an axis by taking a straight line passing through the circle center of the coil and being perpendicular to the coil as the axis; the sealing film can also be split into two sub-sealing films in a mode of being parallel to the axis.

In some embodiments, the sealing film is formed by plating.

Here, the plating molding may refer to a method of covering the coil surface with a sealing film material by using various plating techniques.

Here, the specific technique of coating may be selected according to the actual application scenario, and is not limited herein. As an example, electroplating, electroless plating, or the like may be employed.

In some embodiments, the coils may be coated using a Physical Vapor Deposition (PVD) technique. The method is characterized in that under the vacuum condition, the low-voltage and large-current arc discharge technology is adopted, the target material is evaporated by utilizing gas discharge, the evaporated material is ionized, and the evaporated material or the reaction product thereof is deposited on the coil under the action of an electric field. The film layer plated by the PVD coating technology has the characteristics of high hardness, high wear resistance (low friction coefficient), good corrosion resistance, good chemical stability and the like, and the service life of the film layer is longer. Various single metal films (e.g., aluminum, titanium, zirconium, chromium, etc.), nitride films and carbide films, and oxide films can be prepared.

It should be noted that, by using PVD coating technology, the thickness of the coating film can be as thin as 0.1 μm, so that various physical and chemical properties of the surface of the workpiece can be improved without affecting the original size of the workpiece, and the size of the workpiece can be maintained substantially unchanged without reprocessing after coating.

In addition, the present disclosure also provides a laser radar including the above laser scanning device.

It is obvious that the laser scanning device can be further designed in different embodiments by combining or modifying different embodiments and various technical features in different ways.

The laser scanning device and the lidar comprising the same according to preferred embodiments of the present disclosure have been described above with reference to specific embodiments. It is understood that the above description is intended to be illustrative, and not restrictive, and that various changes and modifications may be suggested to one skilled in the art in view of the foregoing description without departing from the scope of the disclosure. Such variations and modifications are also intended to be included within the scope of the present disclosure.

The above embodiments are only used to illustrate the technical solutions of the present application, and not to limit the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions in the embodiments of the present application.

Claims

1. A laser scanning device, comprising: a coil and a sealing film;

the coil is wound by electromagnetic wires;

the sealing film is used for coating the coil and sealing the coil, and two ends of the electromagnetic wire extend out of the sealing film.

2. The laser scanning apparatus according to claim 1, wherein the sealing film includes a first sub-film and a second sub-film, and wherein the first sub-film and the second sub-film are integrated to form the sealing film.

3. The laser scanning device according to claim 1, wherein an electromagnetic wire hole is provided between the first sub film and the second sub film.

4. The laser scanning device according to claim 1, wherein the color of the outer surface layer of the sealing film is black.

5. The laser scanning device according to claim 1, the sealing film having a thickness of less than 100 microns.

6. The laser scanning apparatus according to claim 1, a material of the sealing film includes polyetherimide.

7. A laser scanning device according to any one of claims 1 to 6, wherein the sealing membrane is formed by integral injection moulding.

8. The laser scanning device according to any one of claims 1 to 6, wherein the sealing membrane is formed by split injection molding.

9. A laser scanning device according to any one of claims 1 to 6, wherein the sealing film is formed by plating.

10. A lidar comprising a laser scanning apparatus as claimed in any of claims 1 to 9.