WO2019227448A1

WO2019227448A1 - Distance detection apparatus

Info

Publication number: WO2019227448A1
Application number: PCT/CN2018/089405
Authority: WO
Inventors: 黄淮; 洪小平
Original assignee: 深圳市大疆创新科技有限公司
Priority date: 2018-05-31
Filing date: 2018-05-31
Publication date: 2019-12-05
Also published as: CN110785675A

Abstract

Provided is a distance detection apparatus (100). The distance detection apparatus (100) comprises a light source (103), a scanning module (102), and a detector (105). A light source (103) is used for emitting a light beam. The scanning module (102) comprises at least two prisms (130, 140) and a driver (150); the driver (150) drives the prisms (130, 140) to rotate, so as to sequentially project, in different directions, the light beams emitted by the light source (103), and receives at least a portion of the return light reflected by a detected object (101); and at at least one moment during the rotation of the prisms (130, 140), a change angle of a transport direction of the light beam after passing through the scanning module (102) is less than 15 degrees. A detector (105) and the light source (103) are placed on the same side of the scanning module (102), in order to convert at least a portion of the return light passing through the scanning module (102) into an electrical signal. The electrical signal is used for measuring the distance of the detected object (101) from the distance detection apparatus (100).

Description

Distance detection device

Technical field

The present application relates to the field of optical detection, and in particular, to a distance detection device.

Background technique

The distance detection device plays an important role in many fields, for example, it can be used on a mobile carrier or a non-mobile carrier for remote sensing, obstacle avoidance, mapping, modeling, etc. In particular, mobile carriers, such as robots, artificially controlled aircraft, unmanned aircraft, cars, and ships, can navigate in complex environments through distance detection devices to implement path planning, obstacle detection, and avoiding obstacles.

Summary of the Invention

The present application provides a distance detection device that can reduce scanning blind areas.

According to an aspect of the embodiments of the present application, a distance detection device is provided. The distance detection device includes: a light source for emitting a light beam; a scanning module including at least two prisms and a driver, the driver drives the prism to rotate to project the light beam emitted by the light source in different directions in sequence, and receives detection At least a part of the reflected light reflected by the object, at least one moment in the rotation of the prism, the angle of change in the transmission direction of the light beam after passing through the scanning module is less than 15 degrees; and a detector and the light source are placed in the scanning The same side of the module is used to convert at least part of the returned light passing through the scanning module into an electrical signal, and the electrical signal is used to measure the distance between the detection object and the distance detection device.

The scanning module of the distance detection device of the present application can change the beam transmission direction at an angle of less than 15 degrees at least one time during the rotation of the prism, so that the beam can be projected into a smaller cone angle range in the middle of the scanning angle range, so that Scanning covers this cone angle range and reduces scanning blind areas.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to explain the technical solutions in the embodiments of the present application more clearly, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are just some embodiments of the application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without paying creative labor.

FIG. 1 is a schematic diagram of an embodiment of a distance detection device of the present application.

FIG. 2 is a schematic diagram of an embodiment of a scanning module of the distance detection device shown in FIG. 1.

FIG. 3 is a schematic diagram of the scanning module shown in FIG. 2 at another moment.

FIG. 4 is a schematic diagram of another embodiment of the scanning module shown in FIG. 1.

Detailed ways

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

Exemplary embodiments will be described in detail here, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with this application. Rather, they are merely examples of devices and methods consistent with certain aspects of the application as detailed in the appended claims.

The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to limit the application. As used in this application and the appended claims, the singular forms "a", "the" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that the term "and / or" as used herein refers to and includes any or all possible combinations of one or more of the associated listed items. Unless stated otherwise, similar words such as "front", "rear", "lower" and / or "upper" are just for convenience of explanation, and are not limited to a position or a spatial orientation. Words such as "connected" or "connected" are not limited to physical or mechanical connections, and may include electrical connections, whether direct or indirect. "Multiple" means at least two.

The distance detection device in the embodiment of the present application includes a light source, a scanning module, and a detector. The light source is used to emit a light beam. The scanning module includes at least two prisms and a driver. The driver drives the prism to rotate in order to project the light beam emitted by the light source in different directions in sequence, and receives at least a part of the return light reflected by the detection object, at least one time during the rotation of the prism, After the light beam passes through the scanning module, the change angle of the transmission direction is less than 15 degrees. The detector and the light source are placed on the same side of the scanning module, and are used to convert at least part of the returned light passing through the scanning module into an electrical signal. The electrical signal is used to measure the distance between the detection object and the distance detection device. The scanning module of the distance detection device of the present application can change the beam transmission direction at an angle of less than 15 degrees at least one time during the rotation of the prism, so that the beam can be projected into a smaller cone angle range in the middle of the scanning angle range, so Scanning covers this cone angle range and reduces scanning blind areas.

The distance detection device of the present application will be described in detail below with reference to the drawings. In the case of no conflict, the features of the following embodiments and implementations can be combined with each other.

FIG. 1 is a schematic diagram of an embodiment of a distance detection device 100. The distance detection device 100 can be used to measure the distance and orientation of the detection object 101 to the distance detection device 100. In one embodiment, the range detection device 100 may include a radar, such as a lidar. The distance detection device 100 can detect the distance between the detection object 101 and the distance detection device 100 by measuring the time of light propagation between the distance detection device 100 and the detection object 101, that is, time-of-flight (TOF).

The distance detection device 100 includes a light source 103, a scanning module 102, and a detector 105. The light source 103 is used to emit a light beam. In one embodiment, the light source 103 may emit a laser beam. The laser beam emitted from the light source 103 is a narrow-bandwidth beam having a wavelength outside the visible light range.

The scanning module 102 projects the light beam emitted by the light source 103 into the space around the distance detection device 100 and receives at least a part of the returned light reflected by the detection object 101. In some embodiments, the distance detection device 100 further includes a collimating lens 104. The collimating lens 104 is placed between the light source 103 and the scanning module 102, and is configured to collimate the light beam emitted by the light source 103 to collimate into parallel light. 119. The scanning module 102 changes the transmission direction of the parallel light 119 and projects the parallel light 119 to a space around the distance detection device 100.

The rotation of the scanning module 102 can project the light beam into different directions, such as

directions

111 and 113, so as to scan the space around the distance detecting device 100. When the light 111 projected by the scanning module 102 hits the detection object 101, a part of the light is reflected by the detection object 101 in a direction opposite to the projected light 111 to the distance detection device 100. The scanning module 102 receives the return light 112 reflected by the detection object 101. A part of the return light 120 reflected by the probe 101 does not propagate to the scanning module 102 and is not received by the scanning module 102.

The detector 105 and the light source 103 are placed on the same side of the scanning module 102 and are used to convert at least part of the returned light passing through the scanning module 102 into an electrical signal. The electric signal is used to measure the distance between the detection object 101 and the distance detection device 100. At least a part of the returned light passing through the scanning module 102 is converted into an electrical signal by the detector 105. In some embodiments, the detector 105 may include an avalanche photodiode. The avalanche photodiode is a high-sensitivity semiconductor device and can use a photocurrent effect to convert an optical signal into an electrical signal.

In some embodiments, the distance detection device 100 further includes a condensing lens 106. The condensing lens 106 is disposed between the detector 105 and the scanning module 102, and is configured to converge the returned light passing through the scanning module 102 to the detector 105.

In one embodiment, the distance detection device 100 includes a reflective element 108. The reflective element 108 is located between the collimating lens 104 and the scanning module 102, and is located between the scanning module 102 and the condensing lens 106. The reflecting element 108 is used to reflect the returned light passing through the scanning module 102 toward the condensing lens 106 and allows the light beam 119 collimated by the collimating lens 104 to pass through. In one embodiment, an opening corresponding to the position of the light source 103 and the collimating lens 104 is formed in the middle of the reflecting element 108, and the collimated parallel light 119 passes through the opening. In another embodiment, the reflective element 108 reflects the light beam emitted by the light source 103. In some embodiments, the reflective element 108 includes a reflective mirror or a reflective prism and the like.

In one embodiment, the condensing lens 106 and the collimating lens 104 are mutually independent lenses. In another embodiment, the condensing lens 106 and the collimating lens 104 are the same lens, and the lens is located on the side of the reflective element 108 facing the scanning module 102. This lens is used to collimate the light beam emitted by the light source 103 and converge the returning light passing through the scanning module 102 to the detector 105. In one embodiment, the condensing lens 106 and / or the collimating lens 104 are coated with an AR coating, which can increase the intensity of the transmitted light beam.

In some embodiments, the distance detection device 100 includes a measurement circuit, such as a TOF unit 107, which can be used to measure TOF to measure the distance of the detection object 101. For example, the TOF unit 107 can calculate the distance by the formula t = 2D / c, where D represents the distance between the distance detection device and the detection object, c represents the speed of light, and t indicates the light projected from the distance detection device 100 to the detection object 101 and The total time taken to return from the detection object 101 to the distance detection device 100. The distance detection device 100 can determine the time t according to the time difference between the light beam 103 emitted by the light source 103 and the return light received by the detector 105, and can further determine the distance D. The distance detection device 100 can also detect the position of the detection object 101 in the distance detection device 100. The distance and orientation detected by the distance detection device 100 can be used for remote sensing, obstacle avoidance, mapping, modeling, navigation, and the like.

In some embodiments, the light source 103 may include a laser diode through which laser light in the nanosecond range is emitted. For example, the laser pulse emitted by the light source 103 lasts 10 ns, and the pulse duration of the returned light detected by the detector 105 is substantially equal to the emitted laser pulse duration. Further, the laser pulse receiving time may be determined, for example, the laser pulse receiving time is determined by detecting a rising edge time of an electrical signal pulse. In some embodiments, the electrical signals can be amplified in multiple stages. In this way, the distance detection device 100 can calculate the TOF by using the pulse reception time information and the pulse emission time information, thereby determining the distance from the detection object 101 to the distance detection device 100.

In some embodiments, the distance detection device 100 includes a window (not shown) located outside the scanning module 102. The light projected by the scanning module 102 is projected through the window to the external space. The light source 103, the scanning module 102, the detector 105, the collimating lens 104, the condensing lens 106, and the reflective element 108 may be packaged in a packaging device, and a window is formed in the packaging device. In one embodiment, the window may include a glass window. In one embodiment, the window is coated with a long-wave pass film. In one embodiment, the long-pass film has a low transmittance for visible light of about 400 nm to 700 nm, and a high transmittance for light in the emission beam band.

In one embodiment, at least one of the inner surface of the window, the surface of the scanning module 102, the lens of the detector 105, the surface of the collimator lens 104, the surface of the condensing lens 106, and the surface of the reflective element 108 is plated with positive Water film. The positive water film is a hydrophilic film, and the oil volatilized when the distance detecting device 100 generates heat can be spread on the surface of the positive water film to prevent oil from forming oil droplets on the surface of the optical element, thereby avoiding the influence of the oil droplets on light transmission. In some embodiments, the surface of the other optical elements of the distance detection device 100 may be coated with a positive water film.

FIG. 2 is a schematic diagram of an embodiment of the scanning module 102 shown in FIG. 1. With reference to FIG. 1, the scanning module 102 includes at least two

prisms

130 and 140 and a driver 150. The driver 150 drives the

prisms

130 and 140 to rotate in order to project the light beams emitted by the light source 103 in different directions in sequence, and receives at least a part of the returned light reflected by the detection object 101. In one embodiment, at least two

prisms

130 and 140 project the light beams emitted by the light source 103 in different directions at different times during a period of rotation.

In one embodiment, the driver 150 includes at least two motors (not shown), and each motor drives a

prism

130, 140 to rotate. The number of motors may be equal to the number of

prisms

130, 140. The controller 151 may be used to control the driver 150. The controller 151 can control the rotation speed of the motor, thereby controlling the rotation speed of the

prisms

130 and 140. In one embodiment, at least two

prisms

130 and 140 are rotated around the same rotation axis 109 at different rotation speeds, and the light beams are sequentially projected in different directions. In another embodiment, at least two

prisms

130, 140 rotate around different axes. In another embodiment, some of the prisms rotate at substantially the same speed.

In the embodiment shown in FIG. 2, the prism includes a first prism 130 and a second prism 140 placed on the side of the first prism 130 away from the light source 103. The first prism 130 includes a first incident surface 131 near the light source 103 and a first exit surface 132 opposite to the first incident surface 131. The second prism 140 includes a second incident surface 141 near the light source 103 and a second exit surface 142 opposite to the second incident surface 141.

The first prism 130 receives a light beam emitted from the light source 103. The collimated light beam 119 emitted from the light source 103 is incident on the first incident surface 131 of the first prism 130. The first prism 130 refracts the light beam 119, and the change angle of the transmission direction of the light beam after passing through the first prism 130 is a. The angle between 119 is a. The light beam 122 emitted from the first prism 130 is incident on the second incident surface 141 of the second prism 140. The second prism 140 refracts the light beam 122, and the refracted light beam 123 is emitted from the second exit surface 142 and is projected around the distance detection device 100.

In one embodiment, the first incident surface 131 and the second incident surface 141 have the same shape, and the first exit surface 132 and the second exit surface 142 have the same shape. At the initial time and / or at least one of the rotations of the

prisms

130 and 140, the first incident surface 131 and the second incident surface 141 extend in the same direction, and the first exit surface 132 and the second exit surface 142 extend in the same direction, as shown in FIG. State shown in 2. In one embodiment, the first incident surface 131 and the second incident surface 141 may both be planar. At an initial time and / or at least one of the rotations of the

prisms

130 and 140, the first incident surface 131 is parallel to the second incident surface 141. In another embodiment, the first incident surface 131 and the second incident surface 141 may both be curved surfaces. The first incident surface 131 and the second incident surface 141 are curved surfaces having the same shape, and the directions, curvatures, and the like of the uneven surfaces are the same. In one embodiment, the first exit surface 132 and the second exit surface 142 may both be planes. At the initial time and / or at least one of the rotations of the

prisms

130 and 140, the first exit surface 132 and the second exit surface 142 are parallel. In another embodiment, the first exit surface 132 and the second exit surface 142 may both be curved surfaces. The first exit surface 132 and the second exit surface 142 are curved surfaces having the same shape.

In one embodiment, the

prisms

130, 140 include wedge-angle prisms. In the embodiment shown in FIG. 2, the first prism 130 and the second prism 140 are both wedge-shaped prisms. The first incident surface 131 and the second incident surface 141 remain parallel during the rotation of the first prism 130 and the second prism 140, the first exit surface 132 extends obliquely with respect to the first incident surface 131, and the second exit surface 142 relative to the first The two incident surfaces 141 extend obliquely. In one embodiment, the first incident surface 131 and the second incident surface 141 are perpendicular to the rotation axis 109, and the collimated light beam 119 is incident to the first prism 130 perpendicular to the first incident surface 131.

At the initial time and / or at least one of the rotations of the

prisms

130 and 140, the first exit surface 132 and the second exit surface 142 are parallel. At this time, the light beam 123 emitted from the second prism 140 and the light beam 122 emitted from the first prism 130 are deflected to the same side with respect to the incident light beam 119. In the state of the first prism 130 and the second prism 140 shown in FIG. 2, compared with the other states, the light beam 123 has the largest deflection angle compared to the light beam 119 and is projected to the outermost edge of the scanning angle range S1.

FIG. 3 is a schematic diagram showing a state of the scanning module 102 shown in FIG. 2 at another moment.

In the embodiment in which the refractive indices of the first prism 130 and the second prism 140 are the same, in the state of the first prism 130 and the second prism 140 shown in FIG. 3, the light beam emitted from the second prism 140 is relative to other states. 124 has the smallest deflection angle compared to beam 119.

In one embodiment, at least one moment during the rotation of the first prism 130 and the second prism 140, when the first incident surface 131 and the second incident surface 141 are symmetrically centered, the first exit surface 132 and the second exit surface 142 When the center is symmetrical, the deflection angle of the light beam 124 emitted from the second prism 140 is smaller than that of the light beam 119. Specifically, in one embodiment, the first incident surface 131 is rotated 180 degrees around the rotation axis 109, which is consistent with the extending direction of the second incident surface 141; the first exit surface 132 is rotated 180 degrees around the rotation axis 109, and extends with the second exit surface 142 The directions are the same; in this state, the deflection angle of the light beam 124 emitted from the second prism 140 is smaller than that of the light beam 119.

In this way, when the light beam 124 is scanned in the scanning area S1, it cannot be projected onto a smaller conical area S2 in the middle of the scanning angle range S1, so that during the rotation of the

prisms

130 and 140, a part of the area cannot be scanned, forming a scanning blind area. .

In the embodiment of the present application, at least two prisms of the scanning module are disposed and / or materials are different, so that at least one moment during the rotation of the at least two prisms of the scanning module, the transmission direction of the light beam changes after passing through the scanning module. The angle is less than 15 degrees, such as 14 degrees, 12 degrees, 10 degrees, 7 degrees, 5 degrees, 0 degrees, or other degrees less than 15 degrees. In some embodiments, at least one moment during the rotation of the at least two prisms of the scanning module, the angle of change in the transmission direction of the light beam after passing through the scanning module is less than 10 degrees. In other embodiments, at least one moment during the rotation of at least two prisms of the scanning module, the angle of change in the transmission direction of the light beam after passing through the scanning module is less than 5 degrees. In this way, the light beam emitted by the light source 103 can be projected into the cone area S2 through the scanning module, thereby reducing the scanning blind area.

In some embodiments, at least one moment during the rotation of the two

prisms

130 and 140 of the scanning module 102, the light beam 119 passes the first prism 130 and deflects outward relative to the optical axis 109, that is, from the first prism 130. The emitted light beam 122 is deflected in a direction away from the optical axis 109 of the light beam 119. The light beam 122 is deflected inwardly through the second prism 140, that is, the light beam 125 emitted from the second prism 140 is deflected toward the optical axis 109 near the light beam 119. The absolute value of the difference between the deflection angle of the light beam 125 emitted from the second prism 140 with respect to the light beam 122 incident on the second prism 140 and the deflection angle b of the light beam 122 with respect to the light beam 119 incident on the first prism 130 is less than 15 degree. In one embodiment, the light beam 122 is deflected inwardly by the second prism 140 and is parallel to the incident light beam 119, that is, the light beam 125 emitted from the second prism 140 is parallel to the light beam 119 incident to the first prism 130.

In other embodiments, at least one moment during the rotation of the two

prisms

130 and 140 of the scanning module 102, the light beam 119 passes through the first prism 130 and deflects outward relative to the optical axis 109, from the first prism 130. The light beam 122 incident on the second prism 140 is deflected outward through the second prism 140. The sum of the deflection angle of the light beam 122 with respect to the light beam 119 and the deflection angle of the light beam 125 emitted from the second prism 140 with respect to the light beam 122 is less than 15 degrees.

In some embodiments, the refractive indices of at least two prisms in the scanning module 102 are different, so that the change angle of the transmission direction of the light beam after passing through the scanning module 102 is less than 15 degrees. Specifically, in the embodiment shown in FIG. 3, the refractive index of the first prism 130 is different from that of the second prism 140, so that the deflection angle of the light beam 125 emitted from the second prism 140 with respect to the incident light beam 119 is at least A time can be less than 15 degrees, so that the light beam 125 emitted from the second prism 140 can be projected into the cone region S2. The deflection angle of the light beam 125 with respect to the incident light beam 119 is smaller than the deflection angle of the light beam 124 with respect to the incident light beam 119, and can be projected into the smaller cone area S2. In another embodiment, the scanning module 102 includes three or more prisms, where some or all of the prisms have different refractive indices.

In the state shown in FIG. 3, the change angle of the transmission direction after the light beam passes through the scanning module 102 is less than 15 degrees. In one embodiment, the angle of change of the transmission direction after the light beam passes through the scanning module 102 is still less than 15 in the previous time or time period and / or the next time or time period in the time corresponding to the state shown in FIG. 3. Degrees, can be projected into the cone area S2 in different directions. In one embodiment, at least one time during the rotation of the

prisms

130 and 140, the transmission direction of the light beam after passing through the scanning module 102 is unchanged. In one embodiment, the light beam 125 emitted from the second prism 140 is parallel to the light beam 119 incident on the first prism 130 at least one time. In one embodiment, in the state shown in FIG. 3, the transmission direction of the light beam does not change after passing through the scanning module 102.

In some embodiments, the scanning module 102 may include other optical elements, such as a lens, a mirror, a grating, an optical phased array (Optical Phased Array), a galvanometer, or any combination of the foregoing optical elements. In one embodiment, the

prisms

130, 140 and other optical elements of the scanning module 102 can rotate around a common axis of rotation 109 to project light in different directions. In another embodiment, the

prisms

130, 140 and / or other optical elements of the scanning module 102 may be rotated about different axes. In yet another embodiment, at least one optical element of the scanning module 102, such as a galvanometer, may vibrate to change the direction of light propagation. In one embodiment, the

prisms

130 and 140 and other optical elements of the scanning module 102 can be rotated at different rotation speeds. In another embodiment, the

prisms

130, 140 and other optical elements of the scanning module 102 may rotate at substantially the same speed.

FIG. 4 is a schematic diagram of another embodiment of the scanning module 202. The embodiment shown in FIG. 4 is similar to the embodiment shown in FIG. 3. Compared to the embodiment shown in FIG. 3, in the embodiment shown in FIG. 4, the center of the first incident surface 231 and the second exit surface 242 is at least one moment during the rotation of the first prism 230 and the second prism 240. Symmetric, the first exit surface 232 and the second incidence surface 241 are symmetrical in the center, so that the change angle of the transmission direction of the light beam after passing through the scanning module 202 is less than 15 degrees. The deflection angle of the light beam 225 emitted from the second prism 240 with respect to the light beam 119 incident on the first prism 230 is less than 15 degrees. The first incident surface 231 and the second exit surface 242 have the same shape, and the first incident surface 231 is rotated 180 degrees about the rotation axis 109, which is the same as the extension direction of the second exit surface 242. The first exit surface 232 and the second incident surface 241 have the same shape, and the first exit surface 232 is rotated 180 degrees about the rotation axis 109, which is the same as the extension direction of the second incident surface 241.

In one embodiment, the first incident surface 231 and the second exit surface 242 are planes. At least one time during the rotation of the first prism 230 and the second prism 240, the first incident surface 231 and the second exit surface 242 are parallel. . In one embodiment, the first exit surface 232 and the second incident surface 241 are planes. At least one moment during the rotation of the first prism 230 and the second prism 240, the first exit surface 232 and the second incident surface 241 are parallel. . In the state shown in FIG. 4, the first incidence surface 231 and the second emission surface 242 are parallel, and the first emission surface 232 and the second incidence surface 241 are parallel. In this state, the change angle of the transmission direction of the light beam after passing through the scanning module 202 is less than 15 degrees. In one embodiment, in the previous time or time period and / or the next time or time period of the time corresponding to the state shown in FIG. 4, the change angle of the transmission direction after the light beam passes through the scanning module 202 is still less than 15 Degrees, can be projected into the cone area S2 in different directions. In one embodiment, in the state shown in FIG. 4, the transmission direction of the light beam does not change after passing through the scanning module 102.

In the embodiment shown in FIG. 4, the first prism 230 and the second prism 240 are wedge-shaped prisms. The first exit surface 232 and the second incident surface 241 remain parallel during the rotation of the first prism 230 and the second prism 240. The first incident surface 231 extends obliquely with respect to the first exit surface 232, and the second exit surface 242 extends obliquely with respect to the second incident surface 241. In one embodiment, the first exit surface 232 and the second incident surface 241 are perpendicular to the rotation axis 109. The incident light beam 119 is perpendicular to the first exit surface 232 and the second incident surface 241.

In another embodiment, the first incident surface 231 and the second exit surface 242 are curved surfaces. In another embodiment, the first exit surface 232 and the second incident surface 241 are curved surfaces. In one embodiment, the refractive index of the first prism 230 is the same as the refractive index of the second prism 240. In another embodiment, the refractive index of the first prism 230 and the refractive index of the second prism 240 may be different. In some other embodiments, the scanning module 202 may include three or more prisms.

It should be noted that in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply these There is any such actual relationship or order between entities or operations. The term "comprising", "including" or any other variation thereof is intended to encompass non-exclusive inclusion, such that a process, method, article, or device that includes a series of elements includes not only those elements but also other elements that are not explicitly listed Elements, or elements that are inherent to such a process, method, article, or device. Without more restrictions, the elements defined by the sentence "including a ..." do not exclude the existence of other identical elements in the process, method, article, or equipment that includes the elements.

The methods and devices provided by the embodiments of the present invention have been described in detail above. Specific examples are used in this document to explain the principles and implementation of the present invention. The descriptions of the above embodiments are only used to help understand the method of the present invention and its implementation. The core idea; meanwhile, for a person of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation and the scope of application. In summary, the content of this description should not be understood as a limitation on the present invention. .

The content disclosed in this patent document contains material which is subject to copyright protection. The copyright is owned by the copyright owner. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure as it appears in the official records and archives of the Patent and Trademark Office.

Claims

A distance detection device, comprising:

Light source for emitting light beams;

The scanning module includes at least two prisms and a driver, the driver drives the prism to rotate to project the light beams emitted by the light source in different directions in sequence, and receives at least a part of the returned light reflected by the detection object. At least one moment during the rotation of the prism, the change angle of the transmission direction after the light beam passes through the scanning module is less than 15 degrees; and

A detector, which is placed on the same side of the scanning module as the light source, and is configured to convert at least part of the returned light passing through the scanning module into an electrical signal, and the electrical signal is used to measure the detection object and the The distance from the detection device.
The distance detection device according to claim 1, wherein at least two of the prisms include a first prism and a second prism placed on a side of the first prism remote from the light source, the first prism The prism includes a first incident surface near the light source and a first exit surface opposite to the first incident surface, and the second prism includes a second incident surface near the light source and the second incident surface Second exit surface.
The distance detection device according to claim 2, wherein at least one time during the rotation of the first prism and the second prism, the centers of the first incident surface and the second exit surface are symmetrical. The centers of the first exit surface and the second incidence surface are symmetrical.
The distance detection device according to claim 3, wherein the first incident surface and the second exit surface are planes, and at least one time during the rotation of the first prism and the second prism , The first incident surface and the second incident surface are parallel.
The distance detection device according to claim 3 or 4, wherein the first exit surface and the second incidence surface are planes, and at least during the rotation of the first prism and the second prism. At one time, the first exit surface and the second incident surface are parallel.
The distance detection device according to claim 5, wherein the first prism and the second prism comprise a wedge-shaped prism, and the first exit surface and the second incident surface are on the first prism. Parallel to the rotation of the second prism, the first incident surface extends obliquely with respect to the first exit surface, and the second exit surface extends obliquely with respect to the second incident surface.
The distance detection device according to claim 3, wherein the first incident surface and the second exit surface are curved surfaces.
The distance detection device according to claim 3 or 7, wherein the first exit surface and the second incident surface are curved surfaces.
The distance detection device according to claim 3, wherein a refractive index of the first prism is the same as a refractive index of the second prism.
The distance detection device according to claim 2, wherein the refractive indices of at least two of the prisms are different.
The distance detecting device according to claim 10, wherein a refractive index of the first prism is different from a refractive index of the second prism.
The distance detection device according to claim 11, characterized in that, at least one time during the rotation of the first prism and the second prism, the center of the first incident surface and the second incident surface are symmetrical The centers of the first exit surface and the second exit surface are symmetrical.
The distance detecting device according to claim 12, wherein the first incident surface and the second incident surface are planes.
The distance detection device according to claim 12 or 13, wherein the first exit surface and the second exit surface are planes.
The distance detection device according to claim 14, wherein the first prism and the second prism include a wedge-shaped prism, and the first incident surface and the second incident surface are on the first prism. In parallel with the rotation of the second prism, the first exit surface extends obliquely with respect to the first incident surface, and the second exit surface extends obliquely with respect to the second incident surface.
The distance detection device according to claim 12, wherein the first incident surface and the second incident surface are curved surfaces.
The distance detection device according to claim 12 or 16, wherein the first exit surface and the second exit surface are curved surfaces.
The distance detecting device according to claim 1, wherein the driver comprises at least two motors, and each of the motors drives one of the prisms to rotate.
The distance detection device according to claim 1, wherein at least two of said prisms rotate at different rotation speeds around the same rotation axis.
The distance detection device according to claim 1, wherein the distance detection device comprises a collimating lens, the collimating lens is placed between the light source and the scanning module, and is configured to emit the light source The outgoing beam is collimated.
The distance detection device according to claim 20, wherein the distance detection device comprises a condensing lens, the condensing lens is placed between the detector and the scanning module, and is configured to pass through the scanning The return light of the module is converged to the detector.
The distance detection device according to claim 21, wherein the condensing lens and the collimating lens are the same lens.
The distance detecting device according to claim 21, wherein the distance detecting device comprises a reflecting element, the reflecting element is located between the collimating lens and the scanning module, and is located between the scanning module and the scanning module. Between the condensing lenses, the reflecting element is configured to reflect the returned light passing through the scanning module toward the condensing lens, and allow the light beam collimated by the collimating lens to pass through.
The distance detection device according to claim 1, wherein at least one time during the rotation of the prism, the transmission direction of the light beam does not change after passing through the scanning module.
The distance detection device according to claim 1, wherein at least one time during the rotation of the prism, a change angle of a transmission direction after the light beam passes through the scanning module is less than 10 degrees.
The distance detection device according to claim 1, wherein at least one time during the rotation of the prism, the angle of change in the transmission direction after the light beam passes through the scanning module is less than 5 degrees.