CN218866096U - Rotating mirror assembly and laser radar - Google Patents

Abstract

The application discloses a rotating mirror assembly and a laser radar, wherein the rotating mirror assembly comprises a shell, a motor, a rotating mirror, a primary speed monitoring device and a secondary speed monitoring device, and the shell is provided with a containing space for containing the motor and the rotating mirror; the motor comprises a stator fixed relative to the shell and an outer rotor capable of rotating relative to the stator; the rotating mirror is fixed on the outer rotor to rotate along with the outer rotor; the primary speed monitoring device comprises a monitoring photoelectric sensor and a sampling position, the sampling position can rotate along with the outer rotor, and the rotation position of the photoelectric monitoring sampling position is monitored so as to monitor the rotation speed of the outer rotor; the secondary speed monitoring device comprises a grating code disc and an encoder, the grating code disc is fixed on the outer rotor to rotate along with the outer rotor, and the encoder monitors gratings on the grating code disc to monitor the angular displacement of the outer rotor in real time. The rotation condition of the motor can be mastered in real time with high precision, the speed is analyzed through the control center and then controlled, and the high-precision closed-loop monitoring of the rotating speed of the motor can be realized.

Description

Rotating mirror assembly and laser radar

Technical Field

The application relates to the technical field of radars, in particular to a rotating mirror assembly and a laser radar.

Background

The laser radar is a system for detecting characteristic information such as a distance, a position, and a speed of a target by emitting laser light. The working principle is that a laser beam is sent to a target, then a received echo reflected from the target is compared with a detection signal, and after appropriate processing is carried out by a control center, relevant information of the target, such as parameters of target distance, direction, height, speed, posture, even shape and the like, can be obtained, so that the target is detected, tracked and identified.

Currently, the optical lens of the laser radar is usually rotated by a motor. An inner rotor motor is usually used as a motor, the optical lens and the rotor can be fixedly connected only by multiple times of switching, the length of a tolerance size chain is caused by multiple times of switching, and finally, an optical accumulated error is caused to be overlarge; this also means that the rotation accuracy that the inner rotor motor can realize is poor, and the optical use requirement of high accuracy cannot be satisfied. And the moment of inertia of the inner rotor motor is small, and the large optical lens cannot be driven to rotate at high speed.

The stability of the high-speed rotation of the motor is an important influence factor of the stability of the laser radar point cloud imaging. Therefore, how to improve the stability of the high-speed rotation of the motor is becoming one of the design targets in the industry.

SUMMERY OF THE UTILITY MODEL

In view of this, the present application provides a rotating mirror assembly and a laser radar capable of improving high-speed rotation stability of a motor.

On the one hand, this application provides a rotating mirror subassembly, including shell, motor, rotating mirror and speed monitoring devices and second grade speed monitoring devices, the shell is equipped with accommodating space, and the motor is located in accommodating space, the motor is including relative the fixed stator of shell and can be relative the rotatory external rotor of stator, the rotating mirror is located in accommodating space and be fixed in order following on the external rotor is rotatory, one-level speed monitoring devices is including monitoring photoelectricity and sampling position, the sampling position can follow the external rotor is rotatory, thereby monitoring photoelectricity monitoring the rotational position of sampling position monitors the rotational speed of external rotor, second grade speed monitoring devices, including grating code wheel and encoder, the grating code wheel is fixed to be set up in order following on the external rotor is rotatory, the encoder monitoring grating on the grating code wheel is with real-time monitoring the angle displacement of external rotor.

In some embodiments, the housing includes a base, the stator includes a fixed shaft and a stator coil fixed on the outer periphery of the fixed shaft, the fixed shaft is fixed on the base and extends in the axial direction of the motor, the base is provided with a recessed portion, and the encoder includes an encoder circuit board fixedly installed in the recessed portion and an encoder detection head electrically connected to the encoder circuit board.

In some embodiments, a boss is disposed in the middle of the recessed portion, the fixing shaft is fixedly mounted on the boss, and a through hole for the boss to pass through is correspondingly disposed on the encoder circuit board.

In some embodiments, the distance between the encoder detection head and the grating code disc is 0.5 mm-1.5 mm.

In some embodiments, the outer rotor includes a rotor yoke rotatable with respect to the stator, and magnetic steel mounted on an inner circumferential surface of the rotor yoke with an air gap therebetween, and a code wheel mounting member mounted on the rotor yoke, the grating code wheel being fixed to the code wheel mounting member.

In some embodiments, the code wheel mounting member is adhered to an end surface of the rotor yoke facing the base, and the grating code wheel is adhered to an end surface of the code wheel mounting member facing the base.

In some embodiments, the rotating mirror assembly includes a pressing plate, the pressing plate axially presses the rotating mirror against the outer rotor, and the sampling site is formed by one or more circumferentially arranged catches or notches, which are formed on the pressing plate.

In some embodiments, the monitoring unit comprises a light emitter and a light receiver which are oppositely arranged at intervals, and the sampling bit can pass through between the light emitter and the light receiver when the outer rotor rotates.

In some embodiments, the housing includes an upper cover, the light emitter and receiver being disposed on the upper cover; the upper cover is fixedly installed together with the base, one end of the fixed shaft is fixedly connected with the base, and the other end of the fixed shaft is fixedly connected with the upper cover, so that two ends of the fixed shaft are supported by the base and the upper cover.

In another aspect, the present application further provides a lidar including the turning mirror assembly as described above.

The utility model discloses a rotating mirror subassembly, motor are external rotor electric machine, and it compares in internal rotor electric machine, and the rotating mirror can directly be fixed on the external rotor in order to follow the external rotor and rotate, does not need many times of switching, has effectively reduced tolerance size chain, guarantees the rotation precision of motor, makes the rotating mirror subassembly can satisfy the optics operation requirement of high accuracy; and the rotary inertia of the outer rotor motor is larger, so that a larger rotating mirror can be driven to rotate at a high speed.

The rotation condition of the motor can be mastered in real time with high precision by monitoring the primary speed of the photoelectric and sampling bit and monitoring the secondary speed of the grating code disc and the encoder, and the high-precision closed-loop monitoring of the rotating speed of the motor can be realized by analyzing the speed by the control center and controlling the speed. In addition, zero position information is arranged on the grating code disc, so that the rotating speed of the rotor can be monitored, and the real-time azimuth position information of the motor rotor during rotation can be mastered by using the zero position information. Therefore, the control center can more accurately correspond the image points in the point cloud to the absolute angles of the rotor, and the stability of the point cloud imaging is improved.

Drawings

Fig. 1 is a schematic structural diagram of a turning mirror assembly according to an embodiment of the present invention;

FIG. 2 is a schematic view of the turning mirror assembly shown in FIG. 1 from another perspective;

FIG. 3 is a cross-sectional schematic view of the rotating mirror assembly shown in FIG. 1;

FIG. 4 is a schematic structural view of the platen shown in FIG. 3;

fig. 5 is a schematic structural diagram of a rotating mirror assembly according to an embodiment of the present invention;

FIG. 6 is a schematic diagram of the configuration of the primary speed monitoring device shown in FIG. 5;

FIG. 7 is a schematic view of the structure of the upper cover shown in FIG. 5;

fig. 8 is an assembly diagram of the base and the encoder according to an embodiment of the present invention.

In the figure: 500. a rotating mirror assembly; 510. a housing; 530. a motor; 550. rotating the mirror; 511. an accommodating space; 512. an air outlet; 551. a gap; 513. a base; 514. an upper cover; 515. a base plate; 516. a lower wall; 517. a cover plate; 518. an upper enclosure wall; 519. round corners; 521. an avoidance part; 523. assembling a reference surface; 524. mounting holes; 531. a stator; 532. an outer rotor; 533. a fixed shaft; 534. a stator coil; 535. a rotor yoke; 536. magnetic steel; 537. a bearing; 538. a spring; 539. pressing a plate; 541. a projection; 543. a rubber pad; 570. a primary speed monitoring device; 571. monitoring the photoelectricity; 572. sampling bits; 573. a signal transmission line; 574. monitoring the circuit board; 525. a groove; 526. a through hole; 590. a secondary speed monitoring device; 591. a grating code disc; 592. an encoder; 593. an encoder circuit board; 594. an encoder detection head; 527. a recessed portion; 528. a boss; 529. a jack; 596. code wheel installed part.

Detailed Description

The present invention will be further described with reference to the accompanying drawings and the detailed description, and it should be noted that the embodiments or technical features described below can be arbitrarily combined to form a new embodiment without conflict.

It should be noted that all directional indicators (such as upper, lower, left, right, front, rear, inner, outer, top, bottom \8230;) in the embodiments of the present invention are only used to explain the relative positional relationship between the components in a specific posture (as shown in the drawings), and if the specific posture is changed, the directional indicator is changed accordingly.

It will also be understood that when an element is referred to as being "secured" or "disposed" to another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present.

Referring to fig. 1 to fig. 3, an embodiment of the present invention provides a turning mirror assembly 500 for a laser radar. The rotating mirror assembly 500 comprises a housing 510, a motor 530 and a rotating mirror 550, wherein the housing 510 is provided with an accommodating space 511, the motor 530 and the rotating mirror 550 are both positioned in the accommodating space 511, and the rotating mirror 550 is connected with the motor 530 to rotate under the driving of the motor 530.

The housing 510 has a cylindrical shape, and the housing space 511 has the same shape as the housing 510, that is, the housing space 511 also has a cylindrical shape, and the turning mirror 550 is located in the housing space 511. The cylindrical housing 510 provides more complete protection for the turning mirror 550 than other shapes, such as a cradle or bowl-shaped housing 510, to reduce the risk of damage to the turning mirror 550.

The housing 510 is provided with an air outlet 512, and the air outlet 512 penetrates through the housing 510 along the radial direction of the housing 510. The outer surface of the turning mirror 550 is spaced from the inner surface of the housing 510, such that a gap 551 is formed between the turning mirror 550 and the housing 510, and the air outlet 512 communicates with the gap 551 to direct the air flow in the gap 551 out of the housing 510 when the turning mirror 550 rotates. Since the housing 510 is cylindrical and the slit 551 itself is small, air resistance of the turning mirror 550 during rotation may be large. By arranging the air outlet 512 on the housing 510, the air outlet 512 can discharge the air flow formed when the rotary mirror 550 rotates out of the housing 510, thereby effectively reducing the air resistance of the rotary mirror 550 in the rotating process, and reducing the power consumption and the wind noise of the motor 530.

The specific position of the air outlet 512 is not limited, and in the present embodiment, the air outlet 512 is disposed on a circumferential wall of the housing 510, that is, a circumferential side wall of the housing 510, and a gap 551 is present between an outer surface of the rotary mirror 550 in the circumferential direction and an inner surface of the housing 510 in the circumferential direction. The air outlet 512 is disposed on the circumferential wall of the housing 510, so that circumferential air can smoothly circulate when the turning mirror 550 rotates, thereby reducing air resistance encountered when the turning mirror 550 rotates.

The specific number of the air outlets 512 is not limited, in this embodiment, the number of the air outlets 512 is multiple, and the multiple air outlets 512 are distributed in several rows at intervals along the circumferential direction of the housing 510. Through setting up a plurality of air outlets 512 and making it arrange at an interval, can make the air current in the gap 551 discharge from corresponding air outlet 512 nearby, effectively reduce the velocity of flow of commentaries on classics mirror 550 air current, and then reduce wind and make an uproar and air resistance.

The specific shape of the air outlet 512 is not limited, and in the present embodiment, the air outlet 512 is rectangular and extends along the circumferential direction of the housing 510.

It is understood that the housing 510 may be integrally formed or may be assembled from multiple parts. In this embodiment, the housing 510 includes a base 513 and an upper cover 514 fixed to the base 513, and the base 513 and the upper cover 514 enclose to form a receiving space 511. By dividing the housing 510 into two parts, a base 513 and a cover 514, it is convenient to mount the motor 530 inside the housing 510 during assembly.

The specific shapes of the base 513 and the upper cover 514 are not limited, and for example, both may be a cylindrical shape or a semi-cylindrical shape (i.e., a shape in which the cylindrical shape is divided into two halves along the central axis thereof), or one of them may be a cylindrical shape and the other may be a plate shape, as long as the base 513 and the upper cover 514 are assembled together to form the cylindrical housing 510.

In the embodiment shown in fig. 1 and 2, the base 513 includes a bottom plate 515 and a lower wall 516 extending from the periphery of the bottom plate 515 to the upper cover 514, the upper cover 514 includes a cover 517 and an upper wall 518 extending from the periphery of the cover 517 to the base 513, the bottom plate 515, the lower wall 516, the upper wall 518 and the cover 517 surround to form a receiving space 511, the upper wall 518 and the lower wall 516 are fixed together to form a circumferential wall of the housing 510, and the air outlet 512 is provided on the upper wall 518 and/or the lower wall 516. In this case, the base 513 and the upper cover 514 are cylindrical.

In another embodiment, the base 513 includes a bottom plate and a bottom wall extending from the periphery of the bottom plate to the top cover 514, the bottom plate, the bottom wall, and the top cover 514 enclose the receiving space 511, the bottom wall forms the peripheral wall of the housing 510, and the air outlet 512 is disposed on the bottom wall. In this case, the base 513 may have a cylindrical shape, and the upper cover 514 may have a cylindrical shape or a plate shape.

In yet another embodiment, the cover 514 includes a cover plate and an upper wall extending from the peripheral base 513 of the cover plate, the base 513, the upper wall and the cover plate define a receiving space 511, the upper wall forms a peripheral wall of the housing 510, and the air outlet 512 is disposed on the upper wall. In this case, the upper cover 514 has a cylindrical shape, and the base 513 may have a cylindrical shape or a plate shape.

In the present embodiment, the upper wall 518 and the lower wall 516 are respectively provided with a plurality of air outlets 512. The plurality of air outlets 512 located in the upper wall 518 are circumferentially spaced apart along the upper cover 514, and the plurality of air outlets 512 located in the lower wall 516 are circumferentially spaced apart along the base 513. The plurality of air outlets 512 at the peripheral wall 516 are spaced apart from the plurality of air outlets 512 at the peripheral wall 518 in the axial direction of the housing 510. Specifically, three air outlets 512 are provided in both the top wall 518 and the bottom wall 516, but other numbers of air outlets 512 may be provided in other embodiments.

As shown in FIG. 3, in some embodiments, the junction of the axially inner surface of the outer shell 510 and the circumferentially inner surface of the outer shell 510 transitions arcuately to form a fillet 519. The rounded corners 519 at the junction facilitate smooth flow of air there, and the relatively sharp corners significantly reduce turbulence of air there, thereby reducing wind resistance and wind noise. Specifically, the inner surface of the bottom wall 515 arcuately transitions with the inner surface of the bottom wall 516 to form a fillet 519, and likewise, the inner surface of the top wall 518 arcuately transitions with the inner surface of the top plate 517.

As shown in fig. 1, the housing 510 is provided with a bypass portion 521, and the bypass portion 521 exposes the rotating mirror 550 to allow the rotating mirror 550 to reflect probe light to a target and receive echo light reflected from the target. By providing the avoiding portion 521 on the housing 510, the housing 510 can be prevented from affecting propagation of the probe light and the echo light.

It is understood that the avoiding portion 521 may be an area formed by a transparent material on the housing 510, or may be a window provided on the housing 510, as long as the propagation of the probe light and the echo light is not affected. In the present embodiment, the escape portion 521 is a window provided on the circumferential wall of the housing 510, the window communicates with the receiving space 511, and a portion where the inner surface of the bottom plate 515 and the inner surface of the lower wall 516 are rounded extends to the window to communicate with the outside of the housing 510.

In this embodiment, the upper cover 514 and the base 513 are respectively provided with a window, and the window located on the upper cover 514 is opposite to and communicated with the window located on the base 513, so as to form a window. The height of the window is greater than the thickness of the turning mirror 550 in the axial direction of the housing 510. Specifically, the window portion in the upper cover 514 is opened to the upper wall 518, and the window portion in the lower cover is opened to the lower wall 516. By providing windows in both the top wall 518 and the bottom wall 516, and the height of the window formed by the two windows being greater than the thickness of the turning mirror 550, it is ensured that the effective optical path is not blocked by the base 513 and the top cover 514, i.e., that the probe light and the echo light are not blocked by the base 513 and the top cover 514.

As shown in fig. 1, an assembly reference surface 523 for positioning an initial position of the rotating mirror 550 is provided on an outer side of the housing 510, and the assembly reference surface 523 is a plane. By providing the assembly reference surface 523 on the housing 510, when the turning mirror assembly 500 is mounted to the lidar housing, the assembly reference surface 523 can be parallel to a plane of an adjacent external element (e.g., a corresponding reference surface of the lidar housing), so that a positioning effect is formed at an initial mounting position of the turning mirror 550, the mounting of the turning mirror assembly 500 is facilitated, a mounting and adjusting procedure is simplified, and the mounting speed is increased.

The specific position of the assembly reference surface 523 is not limited, and in the present embodiment, the assembly reference surface 523 is provided on a section of the plane of the base 513 at the position of the window. In order to facilitate the installation of the positioning tool, the assembly reference surface 523 is provided with an installation hole 524 matched with the positioning tool.

Referring to fig. 3, in some embodiments, the motor 530 includes a stator 531 and an outer rotor 532, the stator 531 is fixed relative to the housing 510, the outer rotor 532 is rotatable relative to the stator 531, and the turning mirror 550 is fixed to the outer rotor 532 to rotate with the outer rotor 532. The motor 530 is an outer rotor motor, and compared with an inner rotor motor, the outer rotor 532 is positioned at the outer side of the stator 531, so that the rotating mirror 550 can be directly fixed on the outer rotor 532, repeated switching is not needed, a tolerance size chain is effectively reduced, the rotation precision of the motor 530 is ensured, and the high-precision optical use requirement is met. And the rotational inertia of the outer rotor motor is larger than that of the inner rotor motor, so that the motor 530 can drive the larger rotary mirror 550 to rotate at a high speed.

The stator 531 includes a fixed shaft 533 and a stator coil 534 installed at an outer periphery of the fixed shaft 533, and both axial ends of the fixed shaft 533 are fixedly connected to the base 513 and the upper cover 514, respectively, so that both ends of the fixed shaft 533 are supported by the base 513 and the upper cover 514, respectively, that is, the entire weight of the stator 531 is supported by the base 513 and the upper cover 514. Specifically, the stator coil 534 is annularly disposed on the outer periphery of the fixed shaft 533 and fixed by glue, two ends of the fixed shaft 533 are respectively fixedly connected to the cover plate 517 and the bottom plate 515 by screws, and the upper wall 518 is fixedly connected to the lower wall 516, so that the stability of the fixed shaft 533 is enhanced, and the outer rotor 532 operates more stably when rotating relative to the stator 531.

The outer rotor 532 includes a rotor yoke 535 and magnetic steel 536, the rotor yoke 535 being rotatable with respect to the stator 531, the magnetic steel 536 being mounted on an inner peripheral surface of the rotor yoke 535, i.e., on a side close to the stator coil 534, with an air gap between the magnetic steel 536 and the stator coil 534. Specifically, the rotor yoke 535 is sleeved on the outer circumference of the stator 531, and is rotatably connected to the fixed shaft 533, and the rotating mirror 550 is fixedly connected to the outer side of the rotor yoke 535. When a current is applied to the stator coil 534 to generate an electromagnetic field, the magnetic steel 536 can rotate under the action of the stator coil 534, and the rotor yoke 535 and the rotating mirror 550 are driven to rotate together.

The specific manner in which the rotor yoke 535 is rotatably connected to the fixed shaft 533 is not limited, and in this embodiment, the outer rotor 532 includes a bearing 537, and the bearing 537 is located between the fixed shaft 533 and the rotor yoke 535. Bearing 537 is fixedly coupled to rotor yoke 535 and rotatably coupled to fixed shaft 533 to thereby rotatably couple fixed shaft 533 and rotor yoke 535. The specific number of the bearings 537 is not limited, and specifically, the bearings 537 are provided in two, and the two bearings 537 are spaced apart in the axial direction of the fixed shaft 533.

A spring 538 is provided between the bearing 537 and the cover 517, and the spring 538 is in a compressed state. The elastic force of the spring 538 acts on the bearing 537 to pre-compress the bearing 537, so as to form a certain limiting effect on the outer rotor 532 in the axial direction, and the outer rotor 532 can rotate around the fixed shaft 533 under the interaction between the stator coil 534 and the magnetic steel 536.

Referring to fig. 3 and 4, in some embodiments, the turning mirror assembly 500 includes a pressure plate 539, the pressure plate 539 can axially press the turning mirror 550 against the outer rotor 532 to fix the turning mirror 550 relative to the outer rotor 532, so that the turning mirror 550 can rotate with the outer rotor 532. Specifically, the turning mirror 550 is hollow and surrounds the outside of the rotor yoke 535. The inner side of the rotary mirror 550 is provided with a protrusion 541, and when the pressing plate 539 is fixedly connected with the rotor yoke 535, the protrusion 541 is pressed on the rotor yoke 535, so that the rotary mirror 550 and the outer rotor 532 are relatively fixed.

The specific shape of the rotating mirror 550 is not limited, and a general prism may be used, and for example, the prism may be a regular polyhedron or an anisotropic polyhedron.

The rubber pad 543 is arranged between the pressing plate 539 and the protrusion 541, the rubber pad 543 can deform, a buffering effect is achieved, and by calculating the compression amount of the rubber pad 543 and the axial gap between the pressing plate 539 and the protrusion 541, damage to the rotating mirror 550 due to excessive pressure when the pressing plate 539 presses the protrusion 541 against the rotor yoke 535 can be avoided.

Referring to fig. 4-7, in some embodiments, the turning mirror assembly 500 includes a primary speed monitoring device 570, the primary speed monitoring device 570 includes a monitoring photo 571 and a sampling bit 572, the sampling bit 572 can rotate with the outer rotor 532, and the monitoring photo 571 monitors the rotational position of the sampling bit 572 to monitor the rotational speed of the outer rotor 532. When the outer rotor 532 rotates relative to the stator 531, the sampling position 572 is driven to move together, and after the sampling position 572 moves to the monitoring photoelectric device 571, the monitoring photoelectric device 571 can monitor the sampling position 572 and monitor the rotation speed of the outer rotor 532 according to the sampling position 572.

The sampling sites 572 are formed by one or more circumferentially disposed tabs or notches formed in the compression plate 539 to enable the sampling sites 572 to rotate with the outer rotor 532. In this embodiment, sampling site 572 is a shutter disposed on platen 539. The number of sampling bits 572 can be increased, and different numbers are suitable for different control schemes, and theoretically, the larger the number is, the higher the angle subdivision accuracy can be realized, and the higher the corresponding speed monitoring accuracy is.

The monitor photo 571 includes a light emitter and a light receiver spaced apart from each other, and the sampling bit 572 can pass through the light emitter and the light receiver when rotating with the outer rotor 532. Specifically, the light emitter and the light receiver are provided on the upper cover 514. When the blocking sheet moves to a position between the light emitter and the receiver along with the outer rotor 532, the blocking sheet blocks the light emitted from the light emitter toward the receiver, that is, the receiver does not receive the light from the light emitter, and the monitoring photoelectric unit 571 can monitor that the blocking sheet is located between the light emitter and the receiver.

Primary speed monitoring device 570 further includes a signal transmission line 573 and a monitoring circuit board 574 electrically coupled to signal transmission line 573, with monitoring electronics 571 being electrically coupled to monitoring circuit board 574. The outer side of the upper cover 514 is provided with a groove 525, a through hole 526 communicated with the accommodating space 511 is arranged in the groove 525, the monitoring circuit board 574 and the signal transmission line 573 are positioned in the groove 525, and the monitoring photoelectric unit 571 penetrates through the through hole 526 and extends into the accommodating space 511.

Referring to fig. 3 and 8, in some embodiments, the turning mirror assembly 500 includes a secondary speed monitoring device 590, the secondary speed monitoring device 590 and the primary speed monitoring device 570 being axially spaced apart from each other. The two-stage speed monitoring device 590 comprises a grating code disc 591 and an encoder 592, wherein the grating code disc 591 is fixedly arranged on the outer rotor 532 to rotate with the outer rotor 532, and the encoder 592 monitors gratings on the grating code disc 591 to monitor the angular displacement of the outer rotor 532 in real time. Specifically, the grating code wheel 591 is arranged coaxially with the outer rotor 532, the encoder 592 is fixed on the base 513, when the outer rotor 532 rotates relative to the stator 531, the grating code wheel 591 rotates relative to the encoder 592, and in the rotating process, the encoder 592 monitors different gratings on the grating code wheel 591, so that the effect of monitoring the angular displacement of the outer rotor 532 and monitoring the rotating speed of the motor 530 is achieved.

The grating code wheel 591 is engraved with a certain number of grating numbers, the grating numbers can be different according to different monitoring accuracy, for example, the number can be 200-5000, and the more the grating numbers, the higher the detection accuracy, so that reasonable selection can be performed according to the detection accuracy requirement. In the embodiment, the grating number of the grating code disc 591 is 1500 lines, and the corresponding angle of each line is 360/1500=0.24 °.

The subdivision of the rotation angle detection is realized through the grating number of the grating code wheel 591, and the precision is improved compared with the subdivision of the rotation angle detection realized by other rotation speed monitoring modes, such as a mode of matching Hall with the pole number of the magnetic steel. Taking the magnetic steel and hall of 8 pole pairs as an example, the achievable angle is subdivided into 360/8=45 °, and the difference between 0.24 ° and 45 ° is large. By monitoring the primary speed of the photoelectric sensor 571 and the sampling bit 572 and the secondary speed of the grating code wheel 591 and the encoder 592, the rotation condition of the motor 530 can be mastered in real time with high precision, and the speed is analyzed by the control center and then controlled, so that the high-precision closed-loop monitoring of the rotation speed of the motor 530 can be realized. In addition, zero position information is set on the grating code disc 591, so that the rotation speed of the outer rotor 532 can be monitored, and the real-time azimuth position information of the outer rotor 532 of the motor 530 during rotation can be mastered by using the zero position information. Therefore, the control center can more accurately correspond the image point in the point cloud to the absolute angle of the outer rotor 532, thereby improving the stability of point cloud imaging.

The encoder 592 includes an encoder circuit board 593 and an encoder detection head 594, the encoder circuit board 593 is fixedly connected with the base 513, and the encoder detection head 594 is electrically connected to a side, close to the grating code wheel 591, of the encoder circuit board 593 for monitoring gratings on the grating code wheel 591. Specifically, the distance between the encoder detection head 594 and the grating code wheel 591 in the axial direction is 0.5mm to 1.5mm, so that the influence on the effective detection caused by too large or too small distance is avoided.

The base 513 is provided with a recessed portion 527, the recessed portion 527 communicates with the housing space 511, and the encoder circuit board 593 is fixedly mounted in the recessed portion 527. The mounting of the encoder 592 is facilitated by providing a recess 527 in the base 513 that receives the encoder circuit board 593.

The recessed portion 527 has a boss 528 formed at a middle portion thereof, and the fixing shaft 533 is fixedly mounted to the boss 528. The encoder circuit board 593 is correspondingly provided with a through hole for the boss 528 to pass through. Specifically, the boss 528 has an insertion hole 529 formed in the middle thereof, and one end of the fixing shaft 533 is inserted into the insertion hole 529. During assembly, the boss 528 can provide a certain limit effect on the fixed shaft 533 and the encoder 592 to facilitate the fixing operation.

A code wheel mounting member 596 is mounted on the rotor yoke 535, and a grating code wheel 591 is fixed to the code wheel mounting member 596. The specific connection manner between the encoder mounting member 596 and the rotor yoke 535 and the grating encoder 591 is not limited, and in this embodiment, the encoder mounting member 596 is adhered to the end surface of the rotor yoke 535 facing the base 513, and the grating encoder 591 is adhered to the end surface of the encoder mounting member 596 facing the base 513, that is, the grating encoder 591 is fixed to the end surface of the rotor yoke 535 close to the base 513 by the encoder mounting member 596. The pasting and fixing mode is simple to operate and convenient to assemble.

The utility model discloses a rotating mirror subassembly, motor are external rotor electric machine, and it compares in internal rotor electric machine, and the rotating mirror can directly be fixed on the external rotor in order to follow the external rotor and rotate, does not need many times of switching, has effectively reduced tolerance size chain, guarantees the rotation precision of motor, makes the rotating mirror subassembly can satisfy the optics operation requirement of high accuracy; and the rotary inertia of the outer rotor motor is larger, so that a larger rotating mirror can be driven to rotate at a high speed.

The rotation condition of the motor can be mastered in real time with high precision by monitoring the primary speed of the photoelectric and sampling bit and monitoring the secondary speed of the grating code disc and the encoder, and the high-precision closed-loop monitoring of the rotating speed of the motor can be realized by analyzing the speed by the control center and controlling the speed. In addition, zero position information is arranged on the grating code disc, so that the rotating speed of the rotor can be monitored, and the real-time azimuth position information of the motor rotor during rotation can be mastered by using the zero position information. Therefore, the control center can more accurately correspond the image points in the point cloud to the absolute angles of the rotor, and the stability of the point cloud imaging is improved.

The above embodiments are only preferred embodiments of the present invention, and the protection scope of the present invention cannot be limited thereby, and any insubstantial changes and substitutions made by those skilled in the art based on the present invention are all within the protection scope of the present invention.

Claims (10)

1. A rotating mirror assembly (500), comprising:

a housing (510) provided with an accommodation space (511);

a motor (530) located in the housing space (511), the motor (530) including a stator (531) fixed to the housing (510) and an outer rotor (532) rotatable relative to the stator (531);

a rotating mirror (550) positioned in the accommodating space (511) and fixed on the outer rotor (532) to rotate with the outer rotor (532);

a primary speed monitoring device (570) comprising a monitoring photo (571) and a sampling bit (572), the sampling bit (572) being rotatable with the outer rotor (532), the monitoring photo (571) monitoring a rotational position of the sampling bit (572) thereby monitoring a rotational speed of the outer rotor (532); and

and the two-stage speed monitoring device (590) comprises a grating code wheel (591) and an encoder (592), the grating code wheel (591) is fixedly arranged on the outer rotor (532) to rotate along with the outer rotor (532), and the encoder (592) monitors gratings on the grating code wheel (591) to monitor the angular displacement of the outer rotor (532) in real time.

2. The rotatable mirror assembly (500) of claim 1, wherein the housing (510) includes a base (513), the stator (531) includes a fixed shaft (533) and a stator coil (534) fixed to an outer periphery of the fixed shaft (533), the fixed shaft (533) is fixed to the base (513) and extends axially along the motor (530), the base (513) is provided with a recessed portion (527), and the encoder (592) includes an encoder circuit board (593) fixedly mounted in the recessed portion (527) and an encoder detection head (594) electrically connected to the encoder circuit board (593).

3. The rotating mirror assembly (500) of claim 2, wherein the recessed portion (527) is provided with a boss (528) at a middle portion, the fixing shaft (533) is fixedly mounted to the boss (528), and the encoder circuit board (593) is correspondingly provided with a through hole for the boss (528) to pass through.

4. The turning mirror assembly (500) according to claim 2, characterized in that the encoder detection head (594) is at a distance of 0.5mm to 1.5mm from the grating code wheel (591).

5. The rotary mirror assembly (500) according to claim 2, wherein the outer rotor (532) comprises a rotor yoke (535) rotatable with respect to the stator (531) and magnetic steel (536) mounted on an inner peripheral surface of the rotor yoke (535), an air gap is provided between the magnetic steel (536) and the stator coil (534), a code wheel mounting member (596) is mounted on the rotor yoke (535), and the grating code wheel (591) is fixed to the code wheel mounting member (596).

6. The rotating mirror assembly (500) of claim 5, wherein said code wheel mount (596) is affixed to an end surface of said rotor yoke (535) facing said base (513), and said grating code wheel (591) is affixed to an end surface of said code wheel mount (596) facing said base (513).

7. The rotating mirror assembly (500) according to any one of claims 2 to 6, wherein the rotating mirror assembly (500) comprises a pressure plate (539), the pressure plate (539) axially presses the rotating mirror (550) against the outer rotor (532), and the sampling site (572) is formed by one or more circumferentially arranged catches or notches, which are formed on the pressure plate (539).

8. The turning mirror assembly (500) according to claim 7, wherein the monitoring electronics (571) comprises a light emitter and a light receiver disposed in spaced opposition, the sampling bits (572) being capable of passing between the light emitter and the light receiver as the outer rotor (532) is rotated.

9. The rotating mirror assembly (500) of claim 8, wherein the housing (510) comprises an upper cover (514), the light emitter and receiver being disposed on the upper cover (514); the upper cover (514) is fixedly installed with the base (513), one end of the fixed shaft (533) is fixedly connected with the base (513), and the other end of the fixed shaft is fixedly connected with the upper cover (514), so that two ends of the fixed shaft (533) are supported by the base (513) and the upper cover (514).

10. Lidar characterized by comprising a rotating mirror assembly (500) according to any of claims 1 to 9.

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