Scanner of laser radar and laser radar

Abstract

The invention provides a scanner of a laser radar and the laser radar, the scanner comprises a reflector and a driver, the driver comprises a rotor and a stator, the rotor comprises a magnetic part, the reflector is arranged on the rotor, and the rotor can swing back and forth on two sides of a balance position. The stator comprises an electromagnetic part, and restoring force enabling the rotor to return to the balance position is generated between the magnetic part and the electromagnetic part. The restoring force generated in the scanner is beneficial to rotor reversing, the power consumption for driving the scanner to move can be reduced, and the scanner is simple in structure and low in cost.

Description

Technical Field

[0001] The present disclosure relates to the field of lidar, and in particular to a scanner of a lidar and a lidar. Background Art

[0002] The scanner in a lidar is used to reflect a detection beam to the outside of the lidar at different angles, and can also be used to receive the echo reflected by the detection beam on an object and reflect the echo to the inside of the lidar. The scanner usually uses a motor to drive a mirror to move, so that the beam incident on the mirror is reflected in different directions. When a conventional motor drives the mirror to reciprocate, the movement and commutation of the mirror are all driven by the Ampere force.

[0003] In a conventional scanner motor, the electromagnetic force between a energized coil and a permanent magnet drives the rotor to move. When the rotor commutes, a large amount of electric energy is provided to the rotor, and the kinetic energy of the rotor is completely consumed. This not only results in a large power consumption, but also limits the movement amplitude of the mirror. The structure of a conventional scanner is complex, occupies a large space, and has a high cost.

[0004] The content in the background art section is only the technology known to the inventor and does not necessarily represent the prior art in this field. Summary of the Invention

[0005] In view of one or more defects in the prior art, the present disclosure provides a scanner of a lidar, including:

[0006] A mirror; and

[0007] A driver, the driver includes:

[0008] A rotor, the rotor includes a magnetic member, the mirror is disposed on the rotor, and the rotor can swing reciprocally on both sides of a balanced position; and

[0009] A stator, the stator includes an electromagnetic member, and a restoring force that returns the rotor to the balanced position is generated between the magnetic member and the electromagnetic member.

[0010] Optionally, the electromagnetic member includes an iron core, and the restoring force is the tangential component of the magnetic force between the iron core and the magnetic member in the movement direction of the rotor.

[0011] Optionally, when the rotor is in a stationary state, when the electromagnetic member applies a first driving force to the rotor, the rotor swings relative to the stator; when the swing amplitude of the rotor reaches a preset amplitude, the electromagnetic member applies a second driving force to the rotor, so that the rotor swings reciprocally on both sides of the balanced position with a preset amplitude and a preset frequency.

[0012] Optionally, the electromagnetic component further includes a coil wound around the iron core. When a first current is applied to the coil, the electromagnetic component exerts a first driving force on the rotor, and when a second current is applied to the coil, the electromagnetic component exerts a second driving force on the rotor, where the first current is greater than the second current.

[0013] Optionally, the magnetic component includes a pair of permanent magnets symmetrically arranged with opposite polarities, and there is a tooth slot between the pair of permanent magnets.

[0014] Optionally, the iron core is arranged outside the rotor, and the shape of the side of the iron core close to the rotor matches the shape of the magnetic component.

[0015] Optionally, when a first current is applied to the coil, the motion state of the rotor changes from static to swinging on both sides of the equilibrium position, and the swinging amplitude gradually increases until the swinging amplitude of the rotor reaches a preset amplitude.

[0016] Optionally, when a second current is applied to the coil, the rotor has effective angle intervals on both sides of the equilibrium position, and the two variable-speed intervals are symmetrically arranged with respect to the equilibrium position.

[0017] Optionally, when the swinging angle of the rotor is within the effective angle interval, the magnitudes of the tangential components of the magnetic force between the pair of permanent magnets and the iron core in the direction of the rotor's motion are the same and the directions are opposite.

[0018] Optionally, when the swinging angle of the rotor exceeds the effective angle interval, the tangential component of the magnetic force between the permanent magnet close to the iron core and the iron core in the direction of the rotor's motion is less than the tangential component of the magnetic force between the other permanent magnet far from the iron core and the iron core in the direction of the rotor's motion, so as to generate a restoring force that causes the rotor to return to the equilibrium position.

[0019] Optionally, when a second current is applied to the coil, there are variable-speed intervals on both sides of the effective angle interval, and the two variable-speed intervals are symmetrically arranged with respect to the equilibrium position.

[0020] Optionally, when the swinging angle of the rotor is within the effective angle interval, the rate of change of the restoring force with respect to the swinging angle of the rotor is k1, and when the swinging angle of the rotor is within the variable-speed interval, the rate of change of the restoring force with respect to the swinging angle of the rotor is k2, where k2 is greater than k1.

[0021] Optionally, the electromagnetic component includes a plurality of coils, and the plurality of coils are all wound around the iron core.

[0022] Optionally, the current directions in each of the multiple coils are the same; or the current directions in each of the multiple coils are controlled individually.

[0023] Optionally, the range of the effective angle interval is adjusted according to the dimension of the iron core in the moving direction of the rotor.

[0024] Optionally, the rotor includes a support member, and the mirror is fixedly arranged on the support member.

[0025] Optionally, the parameters of the magnetic member and the iron core are related to a preset frequency, and the parameters of the magnetic member and the iron core include one or more of: the moment of inertia of the rotor and the mirror, the remanence of the magnetic member, the magnetic permeability of the iron core and the support member, the geometric dimension of the iron core, the position of the magnetic member in the rotor, or the relative position relationship between the magnetic member and the iron core.

[0026] Optionally, the range of the preset frequency is 5 - 40 Hz.

[0027] Optionally, when the rotor is in the equilibrium position, the mirror and the electromagnetic member are located on both sides of the rotor.

[0028] Optionally, the driver further includes a position sensor configured to detect the swing angle of the rotor.

[0029] Optionally, the driver further includes a controller configured to adjust the energizing voltage of the coil according to the swing angle of the rotor obtained by the position sensor.

[0030] Optionally, the present disclosure further includes a lidar, and the lidar includes: a transmitter, a scanner as described above, a receiver, and a processor.

[0031] The transmitter is configured to emit a detection beam, and the detection beam is reflected by the scanner into the environment around the lidar.

[0032] The receiver is configured to receive the echo generated by the detection beam on an object and convert it into an electrical signal.

[0033] The processor is configured to obtain information about the object according to the electrical signal.

[0034] Optionally, when the swing angle of the rotor in the scanner is within the effective angle interval, the transmitter emits a detection beam to the scanner.

[0035] Embodiments of the present disclosure provide a scanner for a lidar. A restoring force that returns the rotor to the equilibrium position is generated between the magnetic member in the rotor and the electromagnetic member in the stator. This restoring force facilitates the commutation of the rotor, can reduce the power consumption for driving the movement of the scanner, and the scanner has a simple structure and low cost.

[0036] Embodiments of the present disclosure further provide a lidar that applies the aforementioned scanner. The scanner reflects the detection beam emitted by the emitter to the outside of the lidar, provides a small current to the scanner, and enables the scanner to swing back and forth on both sides of the equilibrium position, which can reduce the power consumption of the lidar and can have a larger scanning field of view. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The drawings are used to provide a further understanding of the present disclosure and constitute a part of the specification. They are used together with the embodiments of the present disclosure to explain the present disclosure and do not constitute a limitation to the present disclosure. In the drawings:

[0038] Figure 1 A schematic structural diagram of the scanner in some embodiments of the present disclosure is shown;

[0039] Figure 2 A schematic structural diagram of the scanner when the rotor deviates from the equilibrium position in some embodiments of the present disclosure is shown;

[0040] Figure 3A A corresponding schematic diagram between the swing speed of the rotor and the swing angle of the rotor in some embodiments of the present disclosure is shown;

[0041] Figure 3B A corresponding schematic diagram between the restoring force and the swing angle of the rotor in some embodiments of the present disclosure is shown;

[0042] Figure 4A and Figure 4B A schematic structural diagram of the scanner in different embodiments of the present disclosure is shown;

[0043] Figure 5 A frequency response curve of the scanner in some embodiments of the present disclosure is shown;

[0044] Figure 6 A schematic block diagram of the scanner in some embodiments of the present disclosure is shown;

[0045] Figure 7 A schematic block diagram of the lidar in some embodiments of the present disclosure is shown;

[0046] Figure 8 A corresponding schematic diagram between the detection beam emitted by the emitter and the swing angle of the rotor in some embodiments of the present disclosure is shown;

[0047] Figure 9Schematic diagram showing the corresponding relationship between the detection beam emitted by the transmitter and the swing angle of the rotor in other embodiments of the present disclosure. Detailed implementation manners

[0048] In the following, only some exemplary embodiments are simply described. As those skilled in the art can recognize, the described embodiments can be modified in various different ways without departing from the spirit or scope of the present disclosure. Therefore, the drawings and the description are considered to be exemplary in nature rather than restrictive.

[0049] In the description of the present disclosure, it should be understood that the orientation or positional relationships indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present disclosure and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be understood as a limitation of the present disclosure. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of the described features. In the description of the present disclosure, "a plurality" means two or more unless otherwise specifically defined.

[0050] In the description of the present disclosure, it should be noted that unless otherwise clearly specified and limited, the terms "mounted", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection: it can be a mechanical connection, an electrical connection, or can communicate with each other; it can be directly connected, or indirectly connected through an intermediate medium, and can be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present disclosure can be understood according to specific circumstances.

[0051] In this disclosure, unless otherwise clearly specified and defined, a first feature being "on" or "under" a second feature may include direct contact between the first and second features, or may include the first and second features not being in direct contact but in contact through additional features therebetween. Moreover, a first feature being "above", "over" and "on top of" a second feature includes the first feature being directly above and obliquely above the second feature, or merely indicating that the horizontal height of the first feature is higher than that of the second feature. A first feature being "under", "below" and "beneath" a second feature includes the first feature being directly below and obliquely below the second feature, or merely indicating that the horizontal height of the first feature is less than that of the second feature.

[0052] The following disclosure provides many different embodiments or examples for implementing different structures of the present disclosure. To simplify the disclosure of the present disclosure, components and settings of specific examples are described below. Of course, they are merely examples and are not intended to limit the present disclosure. In addition, the present disclosure may repeat reference numerals and / or reference letters in different examples. This repetition is for the purpose of simplification and clarity, and in itself does not indicate the relationship between various embodiments and / or settings discussed. In addition, the present disclosure provides examples of various specific processes and materials, but those of ordinary skill in the art can be aware of the application of other processes and / or the use of other materials.

[0053] Embodiments of the present disclosure will be described below with reference to the accompanying drawings. It should be understood that the embodiments described herein are only for the purpose of illustrating and explaining the present disclosure and are not intended to limit the present disclosure.

[0054] The present disclosure includes a scanner of a lidar, wherein the scanner includes a mirror and a driver. The driver includes a rotor and a stator. The mirror is disposed on the rotor. The rotor includes a magnetic member, and the rotor is arranged to be able to swing reciprocally on both sides of a balanced position, driving the mirror to swing reciprocally. The stator includes an electromagnetic member. A restoring force that can return the rotor to the balanced position is generated between the magnetic member and the electromagnetic member. This restoring force is conducive to the commutation of the rotor, can reduce the power consumption for driving the movement of the scanner, and the scanner has a simple structure and low cost.

[0055] Figure 1 and Figure 2 shows the structure of the scanner 100 of the lidar in some embodiments of the present disclosure. The following will be described in conjunction with Figure 1 and Figure 2 to illustrate the scanner 100.

[0056] Scanner 100 includes a mirror 110 and a driver 120. The mirror 110 can reflect the detection beam to the outside of the lidar, and the mirror 110 can also receive the echo reflected by the object from the detection beam and reflect the echo to the inside of the lidar. The lidar can obtain the position and reflectivity information of the object based on the detection beam and the echo. The driver 120 can drive the mirror 110 to move, can change the incident angle of the detection beam on the mirror 110, and can change the direction of the detection beam reflected by the mirror 110, so as to realize the scanning of the detection beam within the field of view of the lidar.

[0057] The driver 120 includes a rotor 121 and a stator 122. The rotor 121 can swing reciprocally on both sides of the equilibrium position. The mirror 110 is arranged on the rotor 121 and swings with the rotor 121, and can change the direction of the detection beam after being reflected by the mirror 110. For example, when the rotor 121 is in the equilibrium position, it can indicate that the swing angle of the rotor 121 is 0. The rotor 121 swings reciprocally on both sides of the equilibrium position, and the swing angle of the rotor 121 can be expressed as positive or negative. The swing amplitudes of the rotor 121 on both sides of the equilibrium position are the same, and the swing amplitude can be expressed by the swing angle of the rotor 121.

[0058] As Figure 1 shown, the rotor 121 can move around the middle axis. The movement of the rotor 121 is not a 360° circumferential rotation, but a reciprocal swing on both sides of the equilibrium position, as shown by the double-headed arrow in Figure 1 . According to some embodiments of the present disclosure, Figure 1 the position of the rotor 121 in

[0059] is, for example, the equilibrium position. When the rotor 121 is in the equilibrium position (the swing angle of the rotor is 0), the mirror 110 and the electromagnetic member 122a in the stator 122 are located on both sides of the rotor 121.

[0060] As Figure 1 and Figure 2 shown, in some embodiments of the present disclosure, the rotor 121 includes a support member 1213. The mirror 110 is fixedly arranged on the support member 1213. The support member 1213 can be a fixed bracket fixedly arranged outside the rotor bracket 1212, configured to fix the mirror 110. The support member 1213 is made of a soft magnetic material, is easy to magnetize, and can strengthen the magnetic field of the magnetic member 1211.

[0061] The rotor 121 includes a magnetic member 1211, and the magnetic member 1211 is disposed on the rotor bracket 1212. For example Figure 1 As shown, the magnetic member 1211 is disposed on the outer periphery of the rotor bracket 1212, and the magnetic member 1211 can also be configured to match the outer peripheral shape of the rotor bracket 1212. In some other embodiments of the present disclosure, the magnetic member 1211 can also be disposed inside the rotor bracket 1212, for example, attached to the inner surface of the rotor bracket 1212, and the rotor bracket 1212 can conduct magnetism. The magnetic member 1211 can be a permanent magnet, such as a ferrite permanent magnet or a neodymium iron boron permanent magnet.

[0062] The stator 122 is disposed at a fixed position and includes an electromagnetic member 122a. A restoring force that causes the rotor 121 to return to the equilibrium position is generated between the magnetic member 1211 and the electromagnetic member 122a.

[0063] During the process of the rotor 121 reciprocatingly swinging on both sides of the equilibrium position, its moving direction will change, which is referred to as commutation in the present disclosure, indicating the process of the rotor 121 decelerating to 0 and then accelerating in the reverse direction. The movement of the rotor 121 will be described in detail in subsequent embodiments. When the rotor 121 commutes, a restoring force that causes the rotor to return to the equilibrium position is generated between the magnetic member 1211 and the electromagnetic member 122a, which can provide power for the commutation of the rotor 121, facilitate the commutation of the rotor 121, reduce the power consumption of the driver 120 when the rotor 121 commutes, and reduce the power consumption of the lidar.

[0064] The reciprocatingly swinging scanner frequently commutes during operation. In a conventional motor for driving a mirror to reciprocatingly swing, an alternating current is passed through the winding coil, and the rotor is caused to complete commutation by relying on the Ampere force. In a conventional scanner, every time the rotor commutes, the kinetic energy of the rotor will be completely consumed, the kinetic energy of the rotor cannot be recovered, and continuous power supply by the winding coil is required during commutation to provide the power required for the rotor to commute.

[0065] In some embodiments of the present disclosure, a restoring force is generated between the magnetic member 1211 and the electromagnetic member 122a, and the restoring force can provide commutation power for the rotor 121. During one commutation, the rotor 121 experiences a process of deceleration -> speed being 0 -> reverse acceleration. The acceleration direction of a point on the rotor 121 in the circumferential direction is always tangential to the moving direction of the rotor 121 and points to the equilibrium position. During one commutation, the swinging angle of the rotor 121 is always on one side of the equilibrium position, and the direction of the restoring force at least partially coincides with the acceleration direction of a point on the rotor 121 in the circumferential direction. The restoring force is beneficial to the commutation of the rotor 121 and reduces the power consumption of driving the mirror 110 to reciprocatingly swing.

[0066] The restoring force can form a resonant system with the driving force that drives the rotor 121 to swing. At the resonant frequency, a relatively small driving force can cause the rotor 121 to swing significantly. For example, setting the scanning frequency of the scanner in the lidar to the resonant frequency of the resonant system formed by the restoring force and the driving force, and adjusting the parameters of the magnetic member 1211 and the electromagnetic member 122a according to the scanning frequency (resonant frequency) can reduce the power consumption of the lidar.

[0067] In some embodiments of the present disclosure, as Figure 1 shown, the electromagnetic member 122a includes an iron core 1221, and the restoring force is the tangential component of the magnetic force between the iron core 1221 and the magnetic member 1211 in the moving direction of the rotor 121.

[0068] In some embodiments of the present disclosure, the magnetic member 1211 includes, for example, a pair of permanent magnets. The permanent magnets are symmetrically arranged and have opposite polarities. There is a tooth slot between the two permanent magnets. The tooth slot includes the interval between the two permanent magnets, and the size of the tooth slot is one of the parameters of the magnetic member 1211. Changing the size of the tooth slot can change the distribution of the magnetic field around the magnetic member 1211, change the magnitude of the restoring force, and the change rate of the magnitude of the restoring force with the swing angle of the rotor 121.

[0069] As Figure 1 and Figure 2 shown, when the rotor 121 is at the equilibrium position ( Figure 1 the position shown), a pair of permanent magnets in the magnetic member 1211 are located on both sides of the connection line between the axis of the rotor 121 and the shape center of the iron core 1221 and are symmetrically arranged. The permanent magnets can be ferrite permanent magnets or neodymium iron boron permanent magnets, and are, for example, arranged in the shape of arc-shaped magnetic tiles and arranged in the circumferential direction of the rotor 121.

[0070] Taking Figure 1 's plane as a reference, the polarity of the permanent magnet on the left side facing the iron core 1221 is the N pole, hereinafter referred to as magnetic tile N, and the polarity of the permanent magnet on the right side facing the iron core 1221 is the S pole, hereinafter referred to as magnetic tile S. In some other embodiments of the present disclosure, the positions of magnetic tile N and magnetic tile S can also be interchanged, with magnetic tile N on the right side and magnetic tile S on the left side. Or, in some other embodiments of the present disclosure, the magnetic member 1211 can also include multiple permanent magnets. For example, in the direction perpendicular to Figure 1 's paper surface, the magnetic member 1211 includes multiple spaced magnetic tiles.

[0071] When the rotor 121 is at Figure 1In the position shown, the magnetic force between the magnetic tile N and the iron core 1221 and the magnetic force between the magnetic tile S and the iron core 1221 are equal in magnitude and opposite in direction, and the resultant force points to the axis of the rotor 121. The resultant force (restoring force) of the tangential component of the force between the magnetic tile N and the iron core 1221 along the movement direction of the rotor 121 and the tangential component of the force between the magnetic tile S and the iron core 1221 along the movement direction of the rotor 121 is 0.

[0072] When the rotor 121 deviates from the equilibrium position, as shown in FIG. Figure 2 As shown, the rotor 121 rotates clockwise relative to the equilibrium position, the distance between the iron core 1221 and the magnetic tile N increases, the distance between the iron core 1221 and the magnetic tile S decreases, and the angles between the iron core 1221 and the magnetic tile N and the angles between the iron core 1221 and the magnetic tile S also change. The tangential component of the magnetic force between the iron core 1221 and the magnetic tile N and the tangential component of the magnetic force between the iron core 1221 and the magnetic tile S in the direction of motion of the rotor 121 are determined based on the magnetic force value and the aforementioned angles.

[0073] The tangential component of the magnetic force between the magnet N and the core 1221 in the direction of motion of the rotor 121 ( Figure 2 The tangential component of the magnetic force between the magnetic tile S and the iron core 1221 in the direction of motion of the rotor 121 (shown by the dotted arrow on the left) is greater than the tangential component of the magnetic force between the magnetic tile S and the iron core 1221 in the direction of motion of the rotor 121 ( Figure 2 As shown by the dotted arrow on the right side of the figure, under the joint action of the magnetic tile N and the magnetic tile S, a restoring force is generated between the iron core 1221 and the magnetic member 1211, which can make the rotor 121 return to the equilibrium position.

[0074] Figure 2 The length of the dotted arrow in the figure represents the magnitude of the magnetic force between the magnetic tile N and the iron core 1221, the magnitude of the magnetic force between the magnetic tile S and the iron core 1221, and the tangential component of the magnetic force between the left magnetic tile N and the iron core 1221 in the direction of rotation of the rotor 121 ( Figure 2 The dotted arrow on the left side of the figure is in the direction of rotation of the rotor 121 (counterclockwise in the circumferential direction of rotation of the rotor 121) and the tangential component of the magnetic force between the right magnetic tile S and the iron core 1221 in the direction of motion of the rotor 121 ( Figure 2 The direction of the dotted arrow on the right side (clockwise in the rotation circumferential direction of the rotor 121) is opposite. Figure 2 The resultant force of the tangential components represented by the two dotted arrows is the restoring force. The direction of the restoring force is opposite to the direction in which the rotor 121 deviates from the equilibrium position. For example, the rotor 121 is relative to Figure 1 When the position shown in moves clockwise, the direction of the restoring force is counterclockwise.

[0075] When the rotor 121 moves, the magnetic member 1211 and the magnetic field distributed around the magnetic member 1211 move synchronously with the rotor 121. The position of the iron core 1221 in the magnetic field of the magnetic member 1211 changes, and the magnitude and direction of the magnetic force between the iron core 1221 and the magnetic member 1211 also change. By adjusting the parameters of the iron core 1221 and the magnetic member 1211, for example, by changing the magnetic field distribution of the magnetic member 1211, the magnitude and direction of the magnetic force between the iron core 1221 and the magnetic member 1211 can be controlled when the rotor 121 moves to different positions, so that the tangential component of the magnetic force between the iron core 1221 and the magnetic member 1211 in the moving direction of the rotor 121 forms a restoring force.

[0076] In some embodiments of the present disclosure, the iron core 1221 can be made of a soft magnetic material, which is easy to magnetize and has a high magnetic permeability. By adjusting the parameters of the iron core 1221, a greater degree of freedom for adjusting the parameters of the iron core 1221 and the magnetic member 1211 can be provided.

[0077] The direction of the magnetic force between the iron core 1221 and the magnetic member 1211 is related to the position of the iron core 1221 in the magnetic field of the magnetic member 1211. The magnetic force between the iron core 1221 and the magnetic member 1211 can be decomposed into a tangential component along the moving direction of the rotor 121 and a radial component pointing to the axis of the rotor 121. The radial component pointing to the axis of the rotor 121 is always perpendicular to the velocity direction of the rotor 121, and the radial component does not do work on the movement of the rotor 121 and does not change the movement speed of the rotor 121. The tangential component in the moving direction of the rotor 121 is in the same direction as the velocity direction of the rotor 121, which can change the movement speed of the rotor 121 and is beneficial to the commutation of the rotor 121.

[0078] The restoring force is determined by the position of the iron core 1221 in the magnetic field of the magnetic member 1211 and is related to the swing angle of the rotor 121. No additional energy is required to generate the restoring force during the movement of the rotor 121. The interaction between the magnetic member 1211 and the iron core 1221 can be analogized to an energy storage and release model, and the iron core 1221 has different magnetic field potentials at different positions in the magnetic field of the magnetic member 1211.

[0079] When the rotor 1 is commutated, the rotor 121 decelerates, and the rotor 121 continues to move away from the equilibrium position along the moving direction. Part of the kinetic energy of the rotor 121 is converted into the magnetic field potential energy of the iron core 1221 in the magnetic field of the magnetic member 1211, and the magnetic field potential energy increases. When the speed of the rotor v121 is reduced to 0, the rotor 121 accelerates in the reverse direction, and the rotor 121 moves closer to the equilibrium position along the moving direction. The position of the iron core 1221 in the magnetic field of the magnetic member 1211 changes, the magnetic field potential energy decreases, and part of it is converted into the kinetic energy of the rotor 121. Therefore, the energy during the commutation of the rotor 121 is stored and reused, which is beneficial to reducing the power consumption of driving the scanner 100 to swing back and forth.

[0080] The movement of the rotor 121 will be described below in conjunction with different embodiments of the present disclosure. When the scanner 100 is not started, the rotor 121 is in a stationary state, for example, the rotor 121 is at the equilibrium position. When the scanner 100 is running stably, the rotor 121 swings back and forth on both sides of the equilibrium position, and the swing angle and speed of the rotor 121 both change periodically. For example, the time interval for the rotor 121 to pass through the equilibrium position twice in the same movement direction is one period.

[0081] In some embodiments of the present disclosure, the power required for the rotor 121 to transition from a stationary state to a stable operation, as well as the power for the rotor 121 to continuously swing back and forth on both sides of the equilibrium position, is provided by the electromagnetic member 122a. The electromagnetic member 122a can form a variable magnetic field and cooperate with the magnetic member 1211 to drive the movement of the rotor 121. In the present disclosure, the process of the rotor 121 transitioning from a stationary state to a stable operation is referred to as the startup phase, and the process of the rotor 121 continuously swinging back and forth on both sides of the equilibrium position is referred to as the continuous phase.

[0082] In some embodiments of the present disclosure, when the electromagnetic member 122a applies a first driving force to the rotor 121 in a stationary state, the rotor 121 swings relative to the stator 122. When the swing amplitude of the rotor 121 reaches a preset amplitude, the electromagnetic member 122a applies a second driving force to the rotor 121 to cause the rotor 121 to swing back and forth on both sides of the equilibrium position with a preset amplitude and a preset frequency. For example, the preset frequency is the resonance frequency.

[0083] In the startup phase, when the rotor 121 is in a stationary state and the electromagnetic member 122a applies a first driving force to the rotor 121, the rotor 121 begins to move relative to the stator 122. The magnitude of the first driving force determines the swing amplitude of the rotor 121. According to the preset setting, the direction of the first driving force changes to cause the rotor 121 to swing relative to the stator 122. The first driving force can overcome the swing resistance of the rotor 121 and impart an acceleration to the rotor 121. Under the action of the first driving force, the swing amplitude of the rotor 121 gradually increases.

[0084] When the swing amplitude of the rotor 121 reaches a preset amplitude, the electromagnetic member 122a applies a second driving force to the rotor 121. The magnitude of the second driving force determines the swing amplitude of the rotor 121. Under the action of the second driving force, the rotor 121 reciprocally swings on both sides of the equilibrium position with the preset amplitude and preset frequency, and the rotor 121 enters the continuous stage and maintains stable operation, wherein the second driving force can overcome the swing resistance of the rotor 121. The preset amplitude and preset frequency can correspond to the scanning range and scanning frequency of the lidar. For example, the preset frequency determines the direction change of the second driving force. In some embodiments of the present disclosure, during the continuous stage of the rotor 121, the second driving force can be balanced with the swing resistance of the rotor 121. The swing resistance of the rotor 121 during the startup stage and the continuous stage can be set to a fixed value, and the value of the first driving force is greater than the value of the second driving force.

[0085] In some embodiments of the present disclosure, during the startup stage, the electromagnetic member 122a drives the rotor 121 to start moving and maintains the reciprocating movement of the rotor 121 during the continuous stage. A restoring force capable of driving the rotor 121 back to the equilibrium position can be generated between the iron core 1221 of the electromagnetic member 122a and the magnetic member 1211. The electromagnetic member 122a can provide a first driving force and a second driving force to drive the rotor 121 to move. When the rotor 121 moves, the position of the iron core 1221 in the magnetic field of the magnetic member 1211 changes, and a restoring force is generated between the iron core 1221 and the magnetic member 1211, which is beneficial to simplifying the structure of the scanner 100, reducing the occupied space of the lidar, facilitating the miniaturization of the lidar, and being able to reduce the cost of the lidar.

[0086] In some embodiments of the present disclosure, the electromagnetic member 122a further includes a coil 1222. The coil 1222 is wound around the iron core 1221 to form an electromagnet. When a first current is passed through the coil 1222, the electromagnetic member 122a applies a first driving force to the rotor 121 to enable the rotor 121 to enter the startup stage from a stationary state and reciprocally swing relative to the stator 122. The magnitude of the current in the coil 1222 determines the swing amplitude of the rotor 121.

[0087] When a second current is passed through the coil 1222, the electromagnetic member 122a applies a second driving force to the rotor 121, and the first current is greater than the second current. For example, when the swing amplitude of the rotor 121 reaches a preset amplitude, a second current is passed through the coil 1222. At this time, the magnetic field generated by the electromagnetic member 122a changes, and the electromagnetic member 122a applies a second driving force to the rotor 121. The second driving force can overcome the swing resistance of the rotor 121. Under the action of the second driving force and the restoring force generated between the iron core 1221 and the magnetic member 1211, the rotor 121 remains in the continuous stage and reciprocally swings relative to the stator 122 at a preset amplitude and a preset frequency. The magnitude of the current in the coil 1222 determines the swing amplitude of the rotor 121. The preset frequency determines the direction change of the second driving force and the direction change of the current in the coil 1222.

[0088] The first driving force causes the rotor 121 to enter the starting stage. The first current can be set as a current with a changing direction, which changes the direction of the magnetic force between the electromagnetic member 122a and the magnetic member 1211, and changes the motion state of the rotor 121 from rest to swinging on both sides of the equilibrium position. In some embodiments of the present disclosure, when the electromagnetic member 122a provides the first driving force to the rotor 121, the swing amplitude of the rotor 121 can be gradually increased until the swing amplitude of the rotor 121 reaches the preset amplitude, and then the current in the coil 1222 is changed from the first current to the second current. The electromagnetic member 122a provides the second driving force to the rotor 121, so that the rotor 121 remains in the continuous stage.

[0089] In some embodiments of the present disclosure, the first driving force for driving the rotor 121 to start is greater than the second driving force for maintaining the continuous movement of the rotor 121, and the value of the first current is greater than the value of the second current. By changing the structural parameters of the electromagnetic member 122a and the magnetic member 1211, the second driving force can be reduced. Passing a smaller second current through the coil 1222 can maintain the rotor 121 in the continuous stage and reduce the power consumption of the scanner 100.

[0090] In some embodiments of the present disclosure, the iron core 1221 is arranged outside the rotor 121, and the shape of the side of the iron core 1221 close to the rotor 121 can be set to match the shape of the magnetic member 1211, such as Figure 1 and Figure 2 As shown, the shape of the side of the iron core 1221 close to the rotor 121 is set as a curved arc surface. The parameters of the iron core 1221 include the shape and size of the iron core 1221, which can change the magnitude of the restoring force and the change rate of the magnitude of the restoring force with the swing angle of the rotor 121.

[0091] Figure 3AShows the corresponding relationship between the swinging speed of the rotor 121 and the swinging angle of the rotor 121 when a second current is passed through the coil 1222 in an embodiment of the present disclosure (the rotor 121 is in the continuous stage). Figure 3B Shows the corresponding relationship between the restoring force and the swinging angle of the rotor 121 when a second current is passed through the coil 1222 in an embodiment of the present disclosure. The following combines Figure 3A and Figure 3B to describe the motion of the rotor 121 in the continuous stage.

[0092] In some embodiments of the present disclosure, when a second current is passed through the coil 1222, the rotor 121 remains in the continuous stage and swings back and forth on both sides of the equilibrium position. The rotor 121 has an effective angle range on both sides of the equilibrium position, and when the swinging angle of the rotor 121 is within the effective angle range, the rotor 121 swings at a constant speed. As Figure 3A and 3B shown, the swinging angle of the rotor 121 when it is at the equilibrium position is defined as 0°, and the effective angle range is symmetric on both sides of the equilibrium position, such as ±30°. The swinging angle of the rotor 121 changes periodically, where Figure 3A shows the change in the swinging speed of the rotor 121 at different swinging angles. The horizontal axis represents the swinging angle of the rotor 121, and the vertical axis represents the swinging speed of the rotor 121. The effective angle range is expressed as the angular range between the angle of point A and the angle of point B, where the angular value of point A and the angular value of point B are opposite to each other.

[0093] In some embodiments of the present disclosure, the rotor 121 swings at a constant speed within the effective angle range, and the resultant force of the tangential component forces of the rotor 121 in the moving direction is 0. For example, the restoring force is 0, and the second driving force and the swinging resistance of the rotor 121 are balanced. As Figure 3A shown, within the effective angle range (between the angle of point A and the angle of point B), the swinging speed (angular velocity) of the rotor 121 remains unchanged. When the scanner 100 is applied in a lidar and the rotor 121 drives the mirror 110 to swing at a constant speed, the angle turned by the mirror 110 within a fixed time interval (for example, within the emission interval between two detection beams emitted by the laser in the lidar) is fixed, and the detection beams reflected by the mirror 110 and emitted from the lidar are evenly distributed in the lidar field of view, which is beneficial to improving the detection accuracy of the lidar.

[0094] In some embodiments of the present disclosure, when a second current is passed through the coil 1222, the rotor 121 remains in the continuous stage and has a variable speed range on both sides of the effective angle range (for example Figure 3A and Figure 3BBetween the angle of point D and the angle of point B, and between the angle of point A and the angle of point C in it), the rotor 121 commutes within the variable speed range, and the two variable speed ranges are symmetrically arranged with respect to the equilibrium position. Ensure that the scanner 100 operates continuously and stably in the lidar, and the movement period of the rotor 121 changes during the continuous stage.

[0095] The rotor 121 swings uniformly within the effective angle range. When the swing angle of the rotor 121 exceeds the angle of the end point of the effective angle range (the angle of point A or the angle of point B), the rotor 121 continues to move away from the equilibrium position, and the restoring force generated between the magnetic member 1211 and the iron core 1221 increases as the swing angle of the rotor 121 increases. Under the action of the restoring force, as Figure 3A shown, the moving speed of the rotor 121 gradually decreases.

[0096] Until the speed of the rotor 121 decreases to 0, the swing angle of the rotor 121 reaches the maximum angle of the variable speed range ( Figure 3A and Figure 3B the angle of point C or the angle of point D shown in). As Figure 3B shown, when the swing angle of the rotor 121 is within the variable speed range, the restoring force increases as the swing angle of the rotor 121 away from the equilibrium position increases. When the swing angle of the rotor 121 reaches the maximum value, the value of the restoring force also reaches the maximum value.

[0097] Under the action of the restoring force, the rotor 121 starts to accelerate towards the equilibrium position. As the rotor 121 gradually approaches the equilibrium position, the restoring force also decreases. Until the swing angle of the rotor 121 is within the effective angle range, the rotor 121 moves to the angle of point A or the angle of point B. In some embodiments of the present disclosure, when the swing angle of the rotor 121 is within the effective angle range, the restoring force is 0, and the second driving force and the swing resistance of the rotor 121 are balanced in the tangential direction of the moving direction of the rotor 121, which can make the rotor 121 move uniformly within the effective angle range. The swing resistance of the rotor 121 is opposite to the moving direction of the rotor 121, and the direction change period of the second current can be set to correspond to the moving direction of the rotor 121. In the lidar, insufficient machining accuracy will cause errors, and it is difficult to keep the restoring force always 0 within the effective angle range. When determining the parameters of the magnetic member 1211 and the iron core 1221, the restoring force can be roughly kept 0 within the effective angle range. As Figure 3B shown, the restoring force generally approaches 0 within the effective angle range (the angle range between the angle of point A and the angle of point B), with slight fluctuations.

[0098] When the rotor 121 is moving at a constant speed, the change in the swing resistance is small, and the second driving force can be set to be fixed. The direction of the second driving force changes periodically. For example, a second current with a fixed magnitude and a periodically changing direction is passed into the coil 1222, so that the direction of the magnetic field generated by the electromagnetic member 122a changes periodically, forming a second driving force with a periodically changing direction.

[0099] In some embodiments of the present disclosure, as Figure 3B shown, when the swing angle of the rotor 121 is within the effective angle range, the rate of change of the restoring force with respect to the swing angle of the rotor 121 is k1. When the swing angle of the rotor 121 is within the variable speed range, the rate of change of the restoring force with respect to the swing angle of the rotor 121 is k2, and k2 is greater than k1. When the swing angle of the rotor 121 exceeds the effective angle range, the restoring force increases rapidly as the swing angle of the rotor 121 increases.

[0100] When the swing angle of the rotor 121 is within the variable speed range, the kinetic energy of the rotor 121 and the magnetic field potential energy of the iron core 1221 in the magnetic field of the magnetic member 1211 are converted. And the magnetic field potential energy is related to the position of the iron core 1221 in the magnetic field of the magnetic member 1211. The restoring force generated between the iron core 1221 and the magnetic member 1211 can be analogized to the elastic force of a "spring". The iron core 1221 and the magnetic member 1211 can be simplified into a "magnetic spring" structure. As Figure 3B shown, in some embodiments of the present disclosure, when the swing angle of the rotor 121 is within the variable speed range, the rate of change k2 of the restoring force with respect to the swing angle of the rotor 121 is approximately constant, and the stiffness k of the "magnetic spring" is approximately constant. The appropriate stiffness k of the "magnetic spring" can be set by adjusting the parameters of the magnetic member 1211 and the iron core 1221.

[0101] In some embodiments of the present disclosure, the mechanical model of the scanner 100 can be simplified into a "mass-damping-spring" second-order system, and its dynamic transfer function can be expressed as:

[0102]

[0103] where J represents the moment of inertia, c represents the swing resistance, k represents the stiffness of the magnetic spring, s represents the swing frequency of the rotor 121, X represents the stroke of the rotor 121 swinging on both sides of the equilibrium position, and T represents the driving torque provided to the rotor 121. According to the above formula, the power gain X(s) / T(s) of the scanner 100 is not only related to the swing frequency s of the rotor 121, but also related to the stiffness k of the "magnetic spring". In the mechanical model represented by the above formula, a large power gain can be generated at the resonance frequency point, providing a very small driving force (torque), which can cause the rotor 121 to generate a large displacement.

[0104] When the scanner 100 is applied in a lidar, the moving speed of the rotor 121 changes within a variable speed range, and the angle turned by the rotor 121 within a fixed time is not a fixed value. The detection beam reflected on the mirror 110 and emitted from the lidar is unevenly distributed in the lidar field of view. In some embodiments of the present disclosure, when the swing angle of the rotor 121 is within the effective angle range, the lidar emits a detection beam. When the swing angle of the rotor 121 is within the variable speed range, the lidar does not emit a detection beam. The detection beam reflected by the mirror of the scanner forms the field of view of the lidar. Within one swing period of the rotor 121, by reducing the time when the swing angle of the rotor 121 is within the variable speed range, the proportion of the time when the swing angle of the rotor 121 is within the effective angle range can be increased, which is beneficial to increasing the time for the lidar to emit a detection beam, improving the time utilization rate, and also beneficial to reducing the total time of one swing period of the rotor 121. For example, when the swing angle of the rotor 121 is within the variable speed range, increasing the change rate k2 of the restoring force with respect to the swing angle of the rotor 121 can increase the acceleration of the rotor 121 within the variable speed range, reduce the range of the variable speed range, shorten the time when the swing angle of the rotor 121 is within the variable speed range, and within one swing period of the rotor 121, is beneficial to increasing the proportion of the effective angle range and improving the field of view range of the lidar.

[0105] In a lidar, the scanning frequency and scanning range of the scanner 100 correspond to the frequency and range (the range of the effective angle range) of the rotor 121 driving the mirror 110 to move on both sides of the equilibrium position. In some embodiments of the present disclosure, the magnetic member 1211 and the iron core 1221 are set according to a preset frequency. The parameters of the magnetic member 1211 and the iron core 1221 include one or more of the moment of inertia of the rotor 121 and the mirror 110, the remanence of the magnetic member 1211, the magnetic permeability of the iron core 1221 and the support member 1213, the geometric dimensions of the iron core 1221, the position of the magnetic member 1211 in the rotor 121, or the relative positional relationship between the magnetic member 1211 and the iron core 1221.

[0106] The swing amplitude of the rotor 121 is related to the magnitude of the current passed through the coil 1222. A first current is passed through the coil 1222 to enable the swing amplitude of the rotor 121 to reach a preset amplitude. After the swing amplitude of the rotor 121 reaches the preset amplitude, a second current is passed through the coil 1222. The value of the second current can be determined based on the maximum swing amplitude reached when the rotor 121 is static. In some embodiments of the present disclosure, the value of the second current = the current required for the rotor 121 to reach the maximum swing amplitude when static / Q, where Q represents a coefficient related to the damping ratio of the rotor 121. In some embodiments of the present disclosure, the magnitude of the second current is determined based on the damping ratio of the rotor 121.

[0107] Figure 4A andFigure 4B The structure of the scanner 100 in some other embodiments of the present disclosure is shown. In some embodiments of the present disclosure, the electromagnetic member 122a includes a plurality of coils 1222, and the plurality of coils 1222 are all wound around the iron core 1221.

[0108] In some embodiments of the present disclosure, the current directions in each of the plurality of coils 1222 are the same; or the current direction in each of the plurality of coils 1222 is controlled separately. For example, the plurality of coils 1222 in the electromagnetic member 122a are connected in series. Figure 4A and Figure 4B The three coils 1222 shown in can be connected in series together. The current directions in each of the three coils 1222 are the same and are synchronously controlled. The winding directions of the three coils 1222 can be set according to requirements so that the electromagnetic member 122a can form a preset magnetic field after being energized, and provide a first driving force and a second driving force to the rotor 121.

[0109] For example, the position of the rotor 121 in is the equilibrium position. When the rotor 121 swings from the equilibrium position to the position shown in, the current directions introduced into the three coils 1222 are as shown in. Among the three coils 1222, the N pole of the magnetic field generated by the middle coil 1222 is close to the rotor 121, repels the magnetic tile N, and attracts the magnetic tile S. The S pole of the magnetic field generated by the right coil 1222 is close to the rotor 121, repels the magnetic tile S. Under the action of the middle coil 1222 and the right coil 1222, the rotor 121 obtains a clockwise torque. Figure 4A For example, the position of the rotor 121 in is the equilibrium position. When the rotor 121 swings from the equilibrium position to the position shown in, the current directions introduced into the three coils 1222 are as shown in. Among the three coils 1222, the N pole of the magnetic field generated by the middle coil 1222 is close to the rotor 121, repels the magnetic tile N, and attracts the magnetic tile S. The S pole of the magnetic field generated by the right coil 1222 is close to the rotor 121, repels the magnetic tile S. Under the action of the middle coil 1222 and the right coil 1222, the rotor 121 obtains a clockwise torque. Figure 4B For example, the position of the rotor 121 in is the equilibrium position. When the rotor 121 swings from the equilibrium position to the position shown in, the current directions introduced into the three coils 1222 are as shown in. Among the three coils 1222, the N pole of the magnetic field generated by the middle coil 1222 is close to the rotor 121, repels the magnetic tile N, and attracts the magnetic tile S. The S pole of the magnetic field generated by the right coil 1222 is close to the rotor 121, repels the magnetic tile S. Under the action of the middle coil 1222 and the right coil 1222, the rotor 121 obtains a clockwise torque. Figure 4B The magnetic tile N is close to the left coil 1222. The N pole of the magnetic field generated by the left coil 1222 is close to the rotor 121, provides a counterclockwise torque to the rotor 121, and the left coil 1222 does negative work. By adjusting the parameters of the electromagnetic member 122a and the magnetic member 1211, the torque provided by the left coil 1222 and the torque provided by the right coil 1222 can be made to cancel each other out approximately. Under the action of the magnetic field generated by the middle coil 1222, the rotor 121 continues to swing in the clockwise direction. When the swing angle of the rotor 121 in the clockwise direction is greater than the swing angle shown in, the magnetic tile N deviates from the facing position of the left coil 1222 and moves away from the left coil. The magnetic fields generated by the three coils 1222 all provide a clockwise torque to the rotor 121.

[0110] The magnetic tile N is close to the left coil 1222. The N pole of the magnetic field generated by the left coil 1222 is close to the rotor 121, provides a counterclockwise torque to the rotor 121, and the left coil 1222 does negative work. By adjusting the parameters of the electromagnetic member 122a and the magnetic member 1211, the torque provided by the left coil 1222 and the torque provided by the right coil 1222 can be made to cancel each other out approximately. Under the action of the magnetic field generated by the middle coil 1222, the rotor 121 continues to swing in the clockwise direction. When the swing angle of the rotor 121 in the clockwise direction is greater than the swing angle shown in, the magnetic tile N deviates from the facing position of the left coil 1222 and moves away from the left coil. The magnetic fields generated by the three coils 1222 all provide a clockwise torque to the rotor 121. Figure 4B The magnetic tile N is close to the left coil 1222. The N pole of the magnetic field generated by the left coil 1222 is close to the rotor 121, provides a counterclockwise torque to the rotor 121, and the left coil 1222 does negative work. By adjusting the parameters of the electromagnetic member 122a and the magnetic member 1211, the torque provided by the left coil 1222 and the torque provided by the right coil 1222 can be made to cancel each other out approximately. Under the action of the magnetic field generated by the middle coil 1222, the rotor 121 continues to swing in the clockwise direction. When the swing angle of the rotor 121 in the clockwise direction is greater than the swing angle shown in, the magnetic tile N deviates from the facing position of the left coil 1222 and moves away from the left coil. The magnetic fields generated by the three coils 1222 all provide a clockwise torque to the rotor 121.

[0111] When the plurality of coils 1222 in the electromagnetic member 122a are connected in series, the change periods and phases of the currents in each of the coils 1222 are the same, which can simplify the control of the three coils 1222 and has higher stability.

[0112] In some other embodiments of the present disclosure, multiple coils 1222 in the electromagnetic component 122a can also be independent of each other, and the current direction in each coil 1222 can be controlled separately. For example Figure 4A and Figure 4B whether current is applied to the three coils 1222 shown in

[0113] the magnitude of the applied current, and the direction of the applied current are all independently controlled. For example, the electromagnetic component 122a includes three coils 1222, and the currents applied to the three coils 1222 are all independently controlled. The position of the rotor 121 in Figure 4A shown in Figure 4B is the equilibrium position. When the rotor 121 swings (clockwise) from the equilibrium position to the position shown in Figure 4A the directions of the currents applied to the three coils 1222 are as shown in

[0114] and the magnetic fields generated by the three coils 1222 all provide a clockwise torque to the rotor 121. Figure 4B When the rotor 121 passes through the position shown in

[0115] (the N pole of the magnetic tile is facing the left coil 1222) in the clockwise direction, the current direction of the left coil 1222 is changed so that the N pole of the magnetic field generated by the left coil 1222 approaches the rotor 121, continuing to provide a clockwise torque to the rotor 121, or the left coil 1222 is powered off to avoid the left coil 1222 doing negative work. When the rotor 121 swings counterclockwise, the current change is similar to the above process and will not be elaborated here.

[0116] When the currents applied to multiple coils 1222 in the electromagnetic component 122a are independently controlled, the driving efficiency of the driver 120 is higher, and during the swinging process of the rotor 121, the electromagnetic component 122a can always do positive work.

[0117] In some embodiments of the present disclosure, the range of the effective angle interval can be adjusted according to the dimension of the iron core 1221 in the moving direction of the rotor 121. When the electromagnetic member 122a includes a plurality of coils 1222, the shape and structure of the iron core 1221 can also be adjusted to cooperate with the positions of the coils 1222. The rate of change of the restoring force with respect to the swing angle of the rotor 121 is also related to the shape and structure of the iron core 1221, and the range of the effective angle interval is related to the dimension of the iron core 1221 in the moving direction of the rotor 121. By adjusting the geometric dimension of the iron core 1221, such as increasing the number of coils 1222 and improving the coverage range of the electromagnetic member 122a outside the rotor 121, the range of the effective angle interval in the curve of the restoring force varying with the swing angle of the rotor 121 can be adjusted, which is beneficial to increasing the field of view of the lidar.

[0118] As Figure 5 shown, where the dashed line represents the frequency response curve of a conventional motor, and the response (power gain) decreases as the frequency increases. The solid line represents the frequency response curve of the scanner 100 in some embodiments of the present disclosure, and there is a response peak at a certain frequency. The scanning frequency of the scanner 100 is set to the frequency corresponding to the response peak (preset frequency) to enable the scanner 100 to achieve the maximum power gain, which is beneficial to reducing the power consumption of the scanner 100. When the scanner 100 is applied in a lidar, the value range of the preset frequency is 5 - 40 Hz. For example, the preset frequency is determined according to the power consumption of the lidar, such as 10 Hz.

[0119] After determining the operating frequency of the scanner 100 and taking it as the preset frequency, the stiffness k of the "magnetic spring" can be determined by the following formula:

[0120] k = J(2πf) 2

[0121] where f represents the preset frequency, and J represents the moment of inertia of the rotor 121 and the mirror 110. In some embodiments, the moment of inertia J is mainly the moment of inertia of the mirror 110.

[0122] As Figure 6As shown, in some embodiments of the present disclosure, the driver 120 further includes a position sensor 123 that detects the swing angle of the rotor 121. The sensed element in the position sensor 123 can be fixedly arranged on the rotor 121. The sensed element is, for example, a magnetic material. The sensing element in the position sensor 123 can be fixedly arranged on the stator 122. The sensing element is, for example, an induction coil. The swing angle of the rotor 121 is detected by electromagnetic induction. For example, the stator 122 includes a circuit board (not shown in the figure). An induction coil is arranged on the circuit board, and a magnetic material is arranged on the rotor 121. For example, the magnetic material includes ferrite. When the rotor 121 swings relative to the stator 122, the facing area between the ferrite and the induction coil changes. According to the change in the current in the induction coil, the swing angle of the rotor 121 can be determined. In some other embodiments of the present disclosure, the induction coil can also be arranged on the rotor 121, the ferrite is arranged on the stator 122, or other forms of position sensors 123 are arranged.

[0123] In some embodiments of the present disclosure, the driver 120 further includes a controller 124 configured to adjust the energization voltage of the coil 1222 according to the swing angle of the rotor 121 obtained by the position sensor 123. For example, the controller 124 communicates with the position sensor 123, obtains the swing angle of the rotor 121 from the position sensor 123, and adjusts the energization voltage of the coil 1222 according to the swing angle of the rotor 121. The controller 124 includes, for example, a single-chip microcomputer or an MCU. The controller 124 includes a phase locked loop (PLL). The controller 124 can be arranged on the circuit board of the stator 122 or at other positions.

[0124] The controller 124 can also receive the magnitude and direction of the driving force. For example, the controller 124 communicates with the power supply of the coil 1222. The controller 124 determines whether the scanning frequency (the swing frequency of the rotor 121) of the scanner matches a preset frequency. When the scanning frequency of the scanner does not match the preset frequency, the energization voltage of the coil 1222 can be changed through the controller 124. For example, the second current related to the energization voltage is changed.

[0125] In some other embodiments of the present disclosure, the controller 124 determines whether the voltage of the coil 1222 matches the swing angle of the rotor 121 according to the voltage of the coil 1222 and the swing angle of the rotor 121. When the voltage of the coil 1222 does not match the swing angle of the rotor 121, the energization voltage of the coil 1222 can be changed through the controller 124.

[0126] In some embodiments of the present disclosure, when the swing angle of the rotor 12 and the voltage of the coil 1222 match each other, there is a 90-degree phase difference between the swing angle period of the rotor 121 and the direction change period of the second driving force (second current). For example, when the rotor 121 is at the farthest end of the swing amplitude, the swing angle is the largest and the direction of the second driving force (second current) changes. The position sensor 123 can obtain the swing angle of the rotor 121, and the controller 124 can advance the phase of the swing angle of the rotor 121 by 90 degrees through time differentiation to obtain the angular velocity of the rotor 121. The phase difference between the angular velocity change period of the rotor 121 and the direction change period of the second driving force (second current) is 0. For example, when the rotor 121 is at the farthest end of the swing amplitude, the directions of both the angular velocity of the rotor 121 and the second driving force (second current) change.

[0127] The phase difference between the change period of the second driving force and the change period of the angular velocity of the rotor 121 being 0 indicates that during the swing of the rotor 121, the second driving force always does positive work. When the energy input from the outside is equal to the energy consumed by the swing of the rotor 121, the rotor 121 is in a self-excited oscillation state, which can greatly reduce the energy and the power consumption of the swing of the rotor 121. The energy input from the outside can be represented by the product (power) of the second driving force and the angular velocity of the rotor 121. When the swing frequency of the rotor 121 deviates from the preset frequency, the energization voltage of the coil 1222 can be adjusted using a PLL to enable the rotor 121 to maintain the self-excited oscillation state.

[0128] In some embodiments of the present disclosure, the controller 124 can be used to control the swing frequency, swing angle, and angular velocity of the rotor 121, which is beneficial to improving the detection accuracy of the lidar.

[0129] Some embodiments of the present disclosure also provide a lidar 1, as Figure 7 shown. The lidar 1 includes a scanner 100, a transmitter 200, a receiver 300, and a processor 400 as described in the foregoing embodiments. The transmitter 200 can emit a detection beam, and the detection beam is reflected by the scanner 100 into the environment around the lidar 1. The detection beam emitted by the transmitter 200 irradiates the reflector ********** is reflected by the reflector 110 into the environment around the lidar 1, and the reflector 110 is driven by the rotor 121 to move on both sides of the equilibrium position. The reflector 110 scans the detection beam and reflects the detection beam in different directions into the environment around the lidar 1.

[0130] The receiver 300 can receive the echo generated by the reflection of the detection beam on an object and convert the echo into an electrical signal. In some embodiments of the present disclosure, the echo is also reflected to the receiver 300 by the reflector, simplifying the structure of the lidar 1 and reducing the number of components of the lidar 1.

[0131] The processor 400 is signal - connected to the receiver 300 and can obtain information about an object based on the electrical signal of the receiver 300. The information about the object may include the position information of the object. For example, the time - of - flight is determined based on the detection beam and the echo to determine the distance between the object and the lidar 1, and the angle between the object and the lidar 1 is determined according to the current angle of the mirror 110. In some other embodiments, the information about the object further includes the surface characteristics of the object, such as determining the reflectivity of the object surface based on the echo, etc.

[0132] In some embodiments of the present disclosure, when the swing angle of the rotor 121 in the scanner 100 is within the effective angle range, the emitter 200 emits a detection beam towards the scanner 100. The frequency of emitting the detection beam in the emitter 200 corresponds to the swing angle of the mirror 110. For example Figure 8 As shown, when the swing angle of the rotor 121 in the scanner 100 is within the effective angle range (the angular range between the angle at point A and the angle at point B), the emitter 200 emits a detection beam towards the scanner 100. Figure 8 The dashed line in [the figure] represents that the emitter 200 emits a detection beam at the current moment. In the foregoing embodiment, when the swing angle of the rotor 121 is within the effective angle range, the rotor 121 rotates at a constant speed and the angular velocity remains unchanged. Within a fixed time interval, the angle that the rotor 121 drives the mirror 110 to turn through is a fixed value. Within the effective angle range, the emitter 200 can emit detection beams at a fixed frequency. The present disclosure can simplify the control of the emitter 200 by the lidar, so that the emitter 200 emits detection beams at a fixed frequency). When the swing angle that the rotor 121 drives the mirror 110 exceeds the effective angle range, the emitter 200 can be controlled not to emit detection beams.

[0133] In some other embodiments of the present disclosure, the frequency of the emitter 200 emitting the detection beam corresponds to the swing speed of the rotor 121. For example, when the swing speed of the rotor 121 is greater than a first speed, the emitter 200 is controlled to emit a detection beam towards the scanner 100, where the first speed is less than the swing speed of the rotor 121 within the effective angle range. As Figure 9 shown, when the swing speed of the rotor 121 is less than the swing speed of the rotor 121 within the effective angle range, the swing angle of the rotor 121 is within the variable - speed range. Figure 9 The dashed line shown in [the figure] represents that the emitter 200 emits a detection beam.

[0134] When the swing angle of the rotor 121 is within the effective angle range, the emitter 200 can emit a detection beam at a fixed frequency. When the swing angle of the rotor 121 is within the variable speed range, the swing speed of the rotor 121 decreases. It is possible to control the frequency at which the emitter 200 emits the detection beam to the scanner 100 to decrease as the swing speed of the rotor 121 decreases, so that the interval angle (manifested as the point cloud density) of the detection beam reflected by the mirror 110 is fixed. For example Figure 9 As shown in, when within the variable speed range, the dotted line intervals representing the detection beams emitted by the emitter 20 are increased. The present disclosure can expand the available angle of the scanner 100 and increase the scanning range of the lidar 1. When the swing speed of the rotor 121 is low, the swing angle of the rotor 121 is close to the farthest end of the variable speed range. In this case, the value of the restoring force is large, the acceleration of the rotor 121 is large, and the change rate of the swing speed of the rotor 121 is large. When the swing speed of the rotor 121 is less than the first speed, the emitter 200 is controlled not to emit a detection beam to avoid large errors.

[0135] Finally, it should be noted that the above are only embodiments of the present disclosure and are not used to limit the present disclosure. Although the present disclosure has been described in detail with reference to the foregoing embodiments, for those skilled in the art, they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present disclosure shall be included within the protection scope of the present disclosure.

Claims

1. A scanner for a lidar, comprising: A mirror; And A driver, the driver comprising: A rotor, the rotor comprising a magnetic member, the mirror being disposed on the rotor, and the rotor being capable of reciprocatingly swinging on both sides of a balanced position; And A stator, the stator comprising an electromagnetic member, and a restoring force for returning the rotor to the balanced position being generated between the magnetic member and the electromagnetic member.

2. The scanner according to claim 1, wherein the electromagnetic member comprises an iron core, and the restoring force is a tangential component of the magnetic force between the iron core and the magnetic member in the direction of movement of the rotor.

3. The scanner according to claim 2, wherein when the electromagnetic member applies a first driving force to the rotor in a stationary state of the rotor, the rotor swings relative to the stator; when the swinging amplitude of the rotor reaches a preset amplitude, the electromagnetic member applies a second driving force to the rotor so that the rotor reciprocatingly swings on both sides of the balanced position with a preset amplitude and a preset frequency.

4. The scanner according to claim 3, wherein the electromagnetic member further comprises a coil wound around the iron core, when the coil is energized with a first current, the electromagnetic member applies the first driving force to the rotor, and when the coil is energized with a second current, the electromagnetic member applies the second driving force to the rotor, and the first current is greater than the second current.

5. The scanner according to claim 4, wherein the magnetic member comprises a pair of permanent magnets symmetrically disposed with opposite polarities, and there is a tooth slot between the pair of permanent magnets.

6. The scanner according to claim 4, wherein the iron core is disposed outside the rotor, and the shape of the side of the iron core close to the rotor matches the shape of the magnetic member.

7. For the scanner according to claim 5, when the coil is energized with the first current, the motion state of the rotor changes from stationary to swinging on both sides of the balanced position, and the swinging amplitude gradually increases until the swinging amplitude of the rotor reaches the preset amplitude.

8. The scanner according to claim 7, wherein when the coil is energized with the second current, the rotor has an effective angle range on both sides of the balanced position, and when the swinging angle of the rotor is within the effective angle range, the rotor swings at a constant speed. ​ ​ 11. The scanner according to claim 8, wherein when a second current is passed through the coil, variable-speed intervals are provided on both sides of the effective angle interval, and the two variable-speed intervals are symmetrically arranged with respect to the equilibrium position.

12. The scanner according to claim 11, wherein when the swing angle of the rotor is within the effective angle interval, the rate of change of the restoring force with respect to the swing angle of the rotor is k1, and when the swing angle of the rotor is within the variable-speed interval, the rate of change of the restoring force with respect to the swing angle of the rotor is k2, where k2 is greater than k1.

13. The scanner according to claim 4, wherein the electromagnetic member includes a plurality of coils, and the plurality of coils are all wound around the iron core.

14. The scanner according to claim 13, wherein the current directions in each of the plurality of coils are the same; or the current directions in each of the plurality of coils are individually controlled.

15. The scanner according to claim 8, wherein the range of the effective angle interval is adjusted according to the dimension of the iron core in the moving direction of the rotor.

16. The scanner according to any one of claims 8-15, wherein the rotor includes a support member, and the mirror is fixedly arranged on the support member.

17. The scanner according to claim 16, wherein the parameters of the magnetic member and the iron core are related to a preset frequency, and the parameters of the magnetic member and the iron core include: One or more of the moment of inertia of the rotor and the mirror, the remanence of the magnetic member, the magnetic permeability of the iron core and the support member, the geometric dimension of the iron core, the position of the magnetic member in the rotor, or the relative positional relationship between the magnetic member and the iron core.

18. The scanner according to claim 17, wherein the range of the preset frequency is 5-40 Hz.

19. The scanner according to any one of claims 1-15, wherein when the rotor is at the equilibrium position, the mirror and the electromagnetic member are located on both sides of the rotor.

20. The scanner according to any one of claims 4-15, wherein the driver further includes a position sensor configured to detect the swing angle of the rotor.

21. The scanner according to claim 20, wherein the driver further includes a controller configured to adjust the energizing voltage of the coil according to the swing angle of the rotor obtained by the position sensor.

22. A lidar, comprising: A transmitter, a scanner according to any one of claims 1-21, a receiver, and a processor, The transmitter is configured to emit a detection beam, and the detection beam is reflected by the scanner into the environment around the lidar; The receiver is configured to receive the echo generated by the detection beam on an object and convert it into an electrical signal; The processor is configured to obtain information about the object according to the electrical signal.

23. The lidar according to claim 22, wherein when the swing angle of the rotor in the scanner is within the effective angle interval, the transmitter emits a detection beam to the scanner.

Images