Distance measuring device and cleaning robot

Abstract

The distance measuring device includes an optical emitter (101) and at least two photodetectors. The optical emitter (101) is used to emit detection light, and the at least two photodetectors include a first photodetector (102) and a second photodetector (103), the first photodetector (102) is used to receive a first signal light reflected by the object to be measured (100) under the action of the detection light and to output a first echo signal, the second photodetector (103) is used to receive a second signal light reflected by the object to be measured (100) under the action of the detection light and to output a second echo signal, and the distance measuring device obtains the target distance based on the ratio of the first echo signal to the second echo signal.

Description

Technical Field

[0001] This application claims the priority of Chinese Patent Application No. 2023104300682 filed on April 20, 2023, and the entire content of the Chinese patent application is incorporated herein by reference.

[0002] This disclosure relates to a distance measuring device and a cleaning robot.

Background Art

[0003] In the robot position estimation technology, usually, a reflective distance measuring sensor such as a laser or an infrared sensor is used to realize the detection of the distance between the robot and the measurement object. The accuracy of the distance detection result affects the reliability of the robot position estimation and path planning. Therefore, there is a need to provide a distance measuring device that can perform more accurate measurements.

Summary of the Invention

[0004] In a first aspect, an embodiment of the present disclosure provides a distance measuring device including an optical emitter and at least two optical detectors, where the optical emitter is used to emit detection light, the at least two optical detectors include a first optical detector and a second optical detector. The first optical detector is used to receive a first signal light reflected by a measurement object under the action of the detection light and output a first echo signal. The second optical detector is used to receive a second signal light reflected by the measurement object under the action of the detection light and output a second echo signal. The distance measuring device obtains a target distance based on the ratio of the first echo signal and the second echo signal.

[0005] In a second aspect, an embodiment of the present disclosure provides a cleaning robot including a robot body and the distance measuring device described in the first aspect, and the distance measuring device is provided on the robot body.

[0006] The foregoing description is merely an overview of the proposed technologies provided by this disclosure. To provide a clearer understanding of the technical means of this disclosure and to enable implementation in accordance with the specification, and to provide a clearer and easier understanding of the aforementioned and other features and effects of this disclosure, embodiments of this disclosure are given below.

[0007] The drawings herein are incorporated into the specification and constitute part of this specification, illustrating embodiments applicable to this disclosure and are used together with the specification to interpret the principles of this disclosure. Of course, the drawings described below are only a few embodiments of the present invention, and those skilled in the art can obtain other drawings based on these without any creative effort. [Brief explanation of the drawing]

[0008] [Figure 1] Schematic diagram of an exemplary structure of a distance measuring device in an embodiment of the present disclosure. [Figure 2] An exemplary relationship curve between overlapping area and distance in an embodiment of the present disclosure. [Figure 3] An exemplary relationship curve between overlapping area ratio and distance in an embodiment of the present disclosure. [Figure 4] Optical path diagram of target scattered light in an embodiment of the present disclosure [Figure 5] Nine exemplary structural schematic diagrams of a distance measuring device in an embodiment of the present disclosure. [Figure 6] Nine exemplary structural schematic diagrams of a distance measuring device in an embodiment of the present disclosure. [Figure 7] Nine exemplary structural schematic diagrams of a distance measuring device in an embodiment of the present disclosure. [Figure 8] Nine exemplary structural schematic diagrams of a distance measuring device in an embodiment of the present disclosure. [Figure 9] Nine exemplary structural schematic diagrams of a distance measuring device in an embodiment of the present disclosure. [Figure 10] Nine exemplary structural schematic diagrams of a distance measuring device in an embodiment of the present disclosure. [Figure 11] Nine exemplary structural schematic diagrams of a distance measuring device in an embodiment of the present disclosure. [Figure 12]Nine exemplary structural schematic diagrams of a distance measuring device in an embodiment of the present disclosure. [Figure 13] Nine exemplary structural schematic diagrams of a distance measuring device in an embodiment of the present disclosure. [Figure 14] Schematic diagram of the structure of a cleaning robot in an embodiment of the present disclosure. [Modes for carrying out the invention]

[0009] Illustrative embodiments of the present disclosure will be described in more detail below with reference to the drawings. Note that in the drawings, the size of elements may be exaggerated for illustrative purposes. While illustrative embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure can be implemented in various forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to allow for a more complete understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0010] The terms "and / or" as used herein merely describe the relationship between related objects, indicating that three types of relationships are possible. For example, A and / or B can refer to three situations: when A exists alone, when A and B exist simultaneously, and when B exists alone. The terms "multiple" and "at least two" include cases of two or more. Terms such as "first," "second," and "third" are used solely as symbols and do not limit the number or relative order of the objects. Terms such as "front," "back," "up," "down," "left," and "right" are used solely to indicate relative positional relationships, and if the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0011] One embodiment of the present disclosure provides a distance measuring device 10, which, as shown in Figure 1, includes an optical emitter 101 and at least two photodetectors.

[0012] Of these, the optical emitter 101 is used to emit detection light. For example, the detection light may be infrared light or a laser, and this embodiment is not particularly limited in this regard.

[0013] The photodetector comprises at least two photodetectors, a first photodetector 102 and a second photodetector 103. The first photodetector 102 is used to receive a first signal light reflected by the object to be measured 100 under the action of the detection light and to output a first echo signal, and the second photodetector 103 is used to receive a second signal light reflected by the object to be measured 100 under the action of the detection light and to output a second echo signal. The distance measuring device 10 obtains a target distance, i.e., the distance to the object to be measured 100, based on the ratio of the first echo signal to the second echo signal.

[0014] The essence of a reflective sensor is to determine distance based on the intensity (number of echoes) of the signal light reflected back from a reflective surface, and the distance measurement result is susceptible to the influence of the reflective material. When the distance to the object being measured 100 is the same, the reflectivity of the object being measured 100 will differ depending on the material, resulting in different energy levels for the reflected signal light and thus different distance measurement results, which is disadvantageous in guaranteeing the accuracy of the distance measurement result.

[0015] The embodiments of this disclosure are based on a configuration of a pair of optical emitters 101 and a photodetector, and add at least one photodetector to perform two or more tests on the same object to be measured 100 simultaneously. Taking the configuration of the first photodetector 102 and the second photodetector 103 as an example, a first echo signal and a second echo signal can be obtained in a single detection, the ratio of the first echo signal and the second echo signal can be calculated, and the target distance can be further obtained based on this ratio. Since the signal ratio does not depend on the material of the reflective surface, the influence of different materials on the detection result can be effectively eliminated, and the accuracy of the distance detection result can be improved.

[0016] In this specification, mainly an example will be described in which two photodetectors, namely the first photodetector 102 and the second photodetector 103, are provided corresponding to one light emitter 101. In other examples, the number of photodetectors may also be more than two, and this is not particularly limited in this embodiment. For example, in addition to the first photodetector 102 and the second photodetector 103, a third photodetector can also be provided, whereby three sets of echo signals can be obtained. The ratios are calculated two by two to obtain three sets of distance measurement results, and then the average is obtained or the final measurement result is obtained by other methods.

[0017] In actual implementation, the visible regions of the first photodetector 102 and the second photodetector 103 both at least partially overlap with the irradiation region of the light emitter 101, thereby ensuring that both the first photodetector 102 and the second photodetector 103 can receive the reflected light from the measurement object 100 under the action of the detected light. The size of the overlapping area between the visible region and the irradiation region has a positive correlation with the intensity of the reflected signal light received by the photodetector, that is, it can be understood that the larger the overlapping area, the stronger the intensity of the reflected signal light received.

[0018] Thereby, for each photodetector, the relationship between the overlapping area θ(l) and the measurement distance l can be arranged respectively. For example, as shown in FIG. 2, the overlapping area θ(l) may be configured to first increase and then decrease as the measurement distance l increases. In this specification, for the sake of convenience of distinction, the overlapping area between the visible region of the first photodetector 102 and the irradiation region of the light emitter 101 is called the first overlapping area, and the overlapping area between the visible region of the second photodetector 103 and the irradiation region of the light emitter 101 is called the second overlapping area.

[0019] In some examples, the first photodetector 102 and the second photodetector 103 are at equal distances from the measurement object 100. For example, the central axes of the light emitter 101, the first photodetector 102, and the second photodetector 103 are parallel, and along the direction of the central axis, the light-emitting surface of the light emitter 101, the light-incident surface of the first photodetector 102, and the light-incident surface of the second photodetector 103 are flush. At this time, it can be considered that the light emitter 101, the first photodetector 102, and the second photodetector 103 are at equal distances from the same measurement object 100.

[0020] At this time, by arranging the optical paths of the light emitter 101, the first photodetector 102, and the second photodetector 103, when the measurement distances are equal, there are differences between the first overlapping area and the second overlapping area, and within a preset distance range, the ratio between the first overlapping area and the second overlapping area can have a positive or negative correlation with the distance. The preset distance range is designed based on the needs of the actual application scenario.

[0021] For example, let the measurement distance be represented by l, the first overlapping area be represented by θ1(l), and the second overlapping area be represented by θ2(l). As shown in FIG. 3, as an example, within the preset distance range (l1, l2), θ1(l) / θ2(l) has a positive correlation with the distance l. The ratio I1(l) / I2(l) between the photocurrent corresponding to the first echo signal and the photocurrent corresponding to the second echo signal is proportional to θ1(l) / θ2(l). Thereby, the ratio between the voltage value of the first echo signal and the voltage value of the second echo signal can have a positive correlation with the distance l, and based on this, the target distance is determined.

[0022] For example, one could first collect a large amount of sample data and perform curve fitting to determine the correspondence between the ratio of the first and second echo signals and the distance, then actually measure the ratio, and substitute that ratio into the correspondence to determine the target distance. Alternatively, one could construct a correspondence table between the ratio and distance in advance, and then match the actually measured ratio with the correspondence table to obtain the target distance.

[0023] The ratio of the first echo signal to the second echo signal may be obtained by dividing the first echo signal by the second echo signal, or by dividing the second echo signal by the first echo signal, and is set according to the actual needs, and is not particularly limited in this embodiment.

[0024] To facilitate the adjustment of the optical paths of the optical emitter 101, the first photodetector 102, and the second photodetector 103, the distance measuring device 10 further includes a first optical lens 112 corresponding to the first photodetector 102, a second optical lens 113 corresponding to the second photodetector 103, and a third optical lens 111 corresponding to the optical emitter 101. The detection light emitted from the optical emitter 101 passes through the third optical lens 111 to adjust its optical path and then irradiates the surface of the object to be measured 100. The first signal light reflected by the object to be measured 100 under the action of the detection light passes through the first optical lens 112 to adjust its optical path and then is received by the second photodetector 103. The second signal light reflected by the object to be measured 100 under the action of the detection light passes through the second optical lens 113 to adjust its optical path and then is received by the second photodetector 103.

[0025] In actual implementation, to avoid the large-angle detection light emitted from the optical emitter 101 being received by the photodetector and affecting the distance detection result, a baffle plate can be provided between the optical emitter 101 and the photodetector located adjacent to it to block this portion of the large-angle detection light.

[0026] For example, as shown in Figure 4, when the optical emitter 101, the first photodetector 102, and the second photodetector 103 are arranged in order, the first photodetector 102 is provided adjacent to the optical emitter 101 and the second photodetector 103 is provided on the side of the first photodetector 102 away from the optical emitter 101. Therefore, a baffle plate 120 is provided between the optical emitter 101 and the first photodetector 102. The baffle plate 120 prevents large-angle detection light from entering the optical lens of the first photodetector 102 and being received by the first photodetector 102. The baffle plate described herein is a baffle plate having the function of blocking light rays and may be made of, for example, a black light-shielding material.

[0027] In some examples, the light-receiving lens surface of the first optical lens 112, the light-receiving lens surface of the second optical lens 113, and the light-emitting lens surface of the third optical lens 111 are flush, thereby minimizing dust accumulation on the outer lens surfaces. The end of the baffle plate 120 is fitted between the first optical lens 112 and the third optical lens 111, and by making it flush with the light-receiving side of the first optical lens 112 and the light-emitting side of the third optical lens 111, dust accumulation on the lens surfaces is made less likely.

[0028] Furthermore, during their research, the inventors discovered that as usage time increased, dust inevitably accumulated on the light-emitting lens surface of the third optical lens 111. When the detection light emitted from the optical emitter 101 irradiated onto this dust, the Tyndall effect occurred, meaning that scattering occurred around the dust, changing the direction of light propagation. In particular, if dust is present in the lens surface region close to the photodetector, the resulting scattered light is easily received by the first photodetector 102 and the second photodetector 103, causing errors and affecting the final measurement result. For example, a distance measurement result may be generated even though the object to be measured 100 does not exist, leading to a misjudgment.

[0029] As shown in Figure 4, if dust 400 is located at the position indicated by the elliptical dashed frame, the detection light emitted from the optical emitter 101 will irradiate the dust 400, causing scattering. The resulting target scattered light L will enter the first optical lens 112 and then the second optical lens 113, and as a result will be received by the second photodetector 103, leading to an incorrect measurement result.

[0030] In view of this, the distance measuring device 10 provided in one embodiment of the present disclosure further includes a light-shielding plate 121. The light-shielding plate 121 is used to prevent target scattered light from entering the first photodetector 102 and / or the second photodetector 103, effectively improving the interference problem of airborne dust on the lens surface due to the Tyndall effect and helping to improve the accuracy of the distance detection result. The target scattered light is the scattered light formed when the detection light is irradiated by dust on the light-emitting lens surface of the third optical lens 111. The light-shielding plate 121 described herein may be made of a black light-shielding material that has the function of blocking light rays, for example, the same as the baffle plate 120.

[0031] In specific implementation, the provision of the light-shielding plate 121 is related to the arrangement of the light emitter 101, the first photodetector 102, and the second photodetector 103. Let T be the light emitter 101, R1 be the first photodetector 102, and R2 be the second photodetector 103. In this specification, the light emitter 101, the first photodetector 102, and the second photodetector 103 may be arranged in the order TR1R2, or in the order R1TR2.

[0032] Below, we will first describe some exemplary methods for providing the light-shielding plate 121 in the order TR1R2, that is, when the first photodetector 102 is arranged between the photoemitter 101 and the second photodetector 103.

[0033] As a first method, a light-shielding plate 121 is provided between the first photodetector 102 and the second photodetector 103, thereby preventing the target scattered light from entering the second photodetector 103. Furthermore, a baffle plate 120 is provided between the first photodetector 102 and the optical emitter 101 to prevent large-angle detection light emitted from the optical emitter 101 from being received by the first photodetector 102 and the second photodetector 103 and interfering with the distance detection results. For example, by making the end of the baffle plate 120 flush with the light-emitting side lens surface of the third optical lens 111, the accumulation of dust on the lens surface can be reduced.

[0034] In this case, the ratio of the first echo signal to the second echo signal is obtained by dividing the voltage value of the second echo signal by the voltage value of the first echo signal. In this way, the light-shielding plate 121 can prevent scattered light formed by the Tyndall effect from passing through the region where the first photodetector 102 is located and entering the second photodetector 103. Even if the first photodetector 102 has the potential to receive target scattered light, since the numerator, the second echo signal, is zero, the ratio of the voltage value of the second echo signal divided by the voltage value of the first echo signal becomes 0. This effectively avoids erroneous measurement results due to the reception of target scattered light, improves the interference problem of airborne dust on the lens surface due to the Tyndall effect, and helps to improve the accuracy of distance detection results.

[0035] In some examples, considering that the first photodetector 102 and the second photodetector 103 are located adjacent to each other, the first optical lens 112 and the second optical lens 113 can be integrated to save on mold costs.

[0036] As shown in Figure 5, the light-receiving lens surface of the first optical lens 112 and the light-receiving lens surface of the second optical lens 113 are integrally formed, and the light-shielding plate 121 is fitted into the opening between the first optical lens 112 and the second optical lens 113 from the light-exiting side. In other words, the light-receiving lens surfaces of the first optical lens 112 and the second optical lens 113 are not penetrated by the light-shielding plate 121, which allows the first optical lens 112 and the second optical lens 113 to be manufactured integrally, eliminating the need to design a separate mold and making it easy to save on mold costs.

[0037] The distance between the end of the light-shielding plate 121 and the light-receiving lens surfaces of the first optical lens 112 and the second optical lens 113 is determined based on the angle of scattered light that needs to be blocked and the process requirements. The end of the light-shielding plate 121 refers to the end of the first optical lens 112 and the second optical lens 113 that is closer to the light-receiving side.

[0038] In some examples, the first optical lens 112 and the second optical lens 113 can be provided independently of each other. As shown in Figure 6, the end of the light-shielding plate 121 is fitted between the first optical lens 112 and the second optical lens 113, and the end of the light-shielding plate 121, the light-receiving lens surface of the first optical lens 112, and the light-receiving lens surface of the second optical lens 113 can be made flush, thereby reducing dust accumulation on the lens surfaces. Alternatively, as shown in Figure 7, the end of the light-shielding plate 121 can protrude from the light-receiving lens surface of the first optical lens 112 to better block the target scattered light. For example, the end of the light-shielding plate 121 may protrude 0.3 mm to 1 mm from the light-receiving lens surface of the first optical lens 112, for example, 0.3 mm, 0.4 mm, or 0.5 mm, and may be specifically set according to the actual needs.

[0039] As shown in Figure 8, in some examples, the ends of the baffle plate 120 may also protrude from the light-emitting lens surface of the third optical lens 111, thereby preventing the target scattered light from entering the area where the first photodetector 102 is located and being received by the first photodetector 102, further improving the interference problem of airborne dust on the lens surface due to the Tyndall effect, and reducing limitations on the signal processing process. For example, the ends of the baffle plate 120 may protrude 0.3 mm to 1 mm from the light-emitting lens surface of the third optical lens 111, for example, 0.3 mm, 0.4 mm, or 0.5 mm, and may be specifically set according to the actual needs.

[0040] As a second method, as shown in Figure 9, a light-shielding plate 121 is provided between the light emitter 101 and the first photodetector 102. The end of the light-shielding plate 121 is fitted between the first optical lens 112 and the third optical lens 111, and protrudes from the light-emitting side lens surface of the third optical lens 111, thereby preventing target scattered light and large-angle detection light from entering the first photodetector 102 and the second photodetector 103. For example, the end of the light-shielding plate 121 may protrude 0.3 mm to 1 mm from the light-emitting side lens surface of the third optical lens 111, for example, 0.3 mm, 0.4 mm, or 0.5 mm, and may be specifically set according to the actual needs.

[0041] In this case, as shown in Figure 9, there does not need to be any shielding between the first photodetector 102 and the second photodetector 103. Alternatively, as shown in Figure 10, a signal light baffle plate 122 can be provided between the first photodetector 102 and the second photodetector 103. The ends of the signal light baffle plate 122 are located on the light-emitting side of the first optical lens 112 and the second optical lens 113, and do not need to be fitted between the first optical lens 112 and the second optical lens 113. This prevents large-angle signal light emitted from the first optical lens 112 from entering the second photodetector 103, and prevents large-angle signal light emitted from the second optical lens 113 from entering the first photodetector 102. As a result, interference between the two photodetectors is reduced, the accuracy of the distance detection result is improved, and processing costs are reduced without affecting the provision of the first optical lens 112 and the second optical lens 113.

[0042] When the optical emitter 101, the first photodetector 102, and the second photodetector 103 are arranged in the order R1TR2, the optical emitter 101 is located between the first photodetector 102 and the second photodetector 103, and is adjacent to both the first photodetector 102 and the second photodetector 103. In this case, there may be several exemplary methods for providing the light-shielding plate 121, as follows.

[0043] As a first method, as shown in Figure 11, a light-shielding plate 121 is provided between the optical emitter 101 and the first photodetector 102, and the end of the light-shielding plate 121 is fitted between the first optical lens 112 and the third optical lens 111, and is provided so as to protrude from the light-emitting side lens surface of the third optical lens 111. On the one hand, this prevents large-angle detection light from entering the first photodetector 102, and on the other hand, it further prevents the target scattered light from entering the location area of ​​the first photodetector 102 and being received by the first photodetector 102. Furthermore, a baffle plate 120 is provided between the optical emitter 101 and the second photodetector 103, and the end of the baffle plate 120 is fitted between the second optical lens 113 and the third optical lens 111, and is flush with the light-emitting side lens surface of the third optical lens 111, thereby preventing large-angle detection light from entering the second photodetector 103.

[0044] Accordingly, the ratio of the first echo signal to the second echo signal is obtained by dividing the voltage value of the first echo signal by the voltage value of the second echo signal. In this way, when scattered light formed by the Tyndall effect is present, the numerator, the first echo signal, is zero, so the ratio of the voltage value of the first echo signal to the voltage value of the second echo signal becomes 0. This effectively avoids erroneous measurement results due to the reception of scattered light from dust and improves the interference problem of airborne dust on the lens surface due to the Tyndall effect.

[0045] As a second method, as shown in Figure 12, a light-shielding plate 121 is provided between the optical emitter 101 and the second photodetector 103, and the end of the light-shielding plate 121 is fitted between the second optical lens 113 and the third optical lens 111, and is provided so as to protrude from the light-emitting side lens surface of the third optical lens 111. On the one hand, this prevents large-angle detection light from entering the second photodetector 103, and on the other hand, it further prevents the target scattered light from entering the location area of ​​the second photodetector 103 and being received by the second photodetector 103. Furthermore, a baffle plate 120 is provided between the optical emitter 101 and the first photodetector 102, and the baffle plate 120 is fitted between the first optical lens 112 and the third optical lens 111, and is flush with the light-emitting side lens surface of the third optical lens 111, thereby preventing large-angle detection light from entering the first photodetector 102. Accordingly, the ratio of the first echo signal to the second echo signal is determined by dividing the voltage value of the second echo signal by the voltage value of the first echo signal.

[0046] As a third method, as shown in Figure 13, light-shielding plates 121 are provided between the light emitter 101 and the first photodetector 102, and between the light emitter 101 and the second photodetector 103. The method for providing the light-shielding plates 121 can be found in the first and second methods described above, so a detailed explanation is omitted here. This prevents the target scattered light from both sides from entering the first photodetector 102 and the second photodetector 103.

[0047] Furthermore, one embodiment of the present disclosure further provides a cleaning robot, as shown in Figure 14, the cleaning robot 20 comprising a robot body 200 and a distance measuring device 10 provided in any of the above embodiments, the distance measuring device 10 being mounted on the robot body 200. The specific structure of the robot body 200 and the mounting position of the distance measuring device 10 on the robot body 200 are determined based on the needs of the actual application scene. For example, the cleaning robot 20 may be a robotic vacuum cleaner, a mop robot, a wet / dry cleaning robot, or a window cleaning robot, and this embodiment is not particularly limited thereto.

[0048] Taking a robotic vacuum cleaner as an example, by providing the distance measuring device 10 on the side of the robot body 200, for example the right side, in order to enable obstacle detection along the wall of the robotic vacuum cleaner, the distance detection between the robotic vacuum cleaner and the wall can be achieved more accurately, and the reliability of the travel path planning along the wall can be improved.

[0049] Each embodiment in this disclosure is described in an incremental manner, with emphasis on the differences between each embodiment and the others, and any similar or identical parts between embodiments should be referenced to one another.

[0050] As those skilled in the art will understand, the descriptions relating to any of the embodiments described above are merely illustrative and not intended to limit the scope of this disclosure to these examples. In accordance with the spirit of this disclosure, the technical features of the embodiments or different embodiments can be combined, the steps can be performed in any order, and many other variations of one or more embodiments of this disclosure exist, but for the sake of brevity, detailed descriptions of these are omitted.

[0051] While exemplary embodiments of this disclosure have been described, those skilled in the art, knowing the basic creative concepts, can make further changes and modifications to these embodiments. Accordingly, the appended claims are intended to be construed as including the exemplary embodiments and all changes and modifications that fall within the scope of this disclosure.

[0052] In a first embodiment, one embodiment of the present disclosure provides a ranging device including an optical emitter and at least two photodetectors. The aforementioned optical emitter is used to emit detection light. The at least two photodetectors include a first photodetector and a second photodetector, the first photodetector being used to receive a first signal light reflected by the object under the action of the detection light and to output a first echo signal, the second photodetector being used to receive a second signal light reflected by the object under the action of the detection light and to output a second echo signal, and the distance measuring device obtains a target distance based on the ratio of the first echo signal to the second echo signal.

[0053] In one selective example, the first photodetector and the second photodetector are at equal distances from the object to be measured. Within a predetermined distance range, the ratio of the first overlapping area to the second overlapping area has a positive or negative correlation with the distance, wherein the first overlapping area is the overlapping area between the visible region of the first photodetector and the irradiation region of the photoemitter, and the second overlapping area is the overlapping area between the visible region of the second photodetector and the irradiation region of the photoemitter.

[0054] In one selective example, the distance measuring device further includes a first optical lens, a second optical lens, a third optical lens, and a light shield, wherein detection light emitted from the light emitter is emitted through the third optical lens, the first signal light enters the first photodetector through the first optical lens, and the second signal light enters the second photodetector through the second optical lens. The light-shielding plate is used to prevent target scattered light from entering the first and / or second photodetector, wherein the target scattered light is the scattered light formed when the detection light is irradiated onto dust on the light-emitting lens surface of the third optical lens.

[0055] In one selective example, the first photodetector is positioned between the photoemitter and the second photodetector. A light-shielding plate is provided between the first photodetector and the second photodetector to prevent the target scattered light from entering the second photodetector.

[0056] In one selective example, the light-receiving lens surface of the first optical lens and the light-receiving lens surface of the second optical lens are integrally provided, and the light-shielding plate is fitted into the opening between the first optical lens and the second optical lens from the light-exiting side.

[0057] In one optional example, the first optical lens and the second optical lens are provided independently of each other, and the end of the light-shielding plate is fitted between the first optical lens and the second optical lens. The end of the light-shielding plate, the light-receiving lens surface of the first optical lens, and the light-receiving lens surface of the second optical lens are flush, or the end of the light-shielding plate protrudes from the light-receiving lens surface of the first optical lens.

[0058] In one selective example, the distance measuring device further includes a baffle plate, the baffle plate being provided between the optical emitter and the first photodetector, The end of the baffle plate is fitted between the first optical lens and the third optical lens, and the end of the baffle plate is flush with the light-emitting side lens surface of the third optical lens, or the end of the baffle plate protrudes from the light-emitting side lens surface of the third optical lens.

[0059] In one selective example, the end of the baffle plate protrudes 0.3 mm to 1 mm from the light-emitting lens surface of the third optical lens.

[0060] In one selective example, the first photodetector is positioned between the photoemitter and the second photodetector. A light-shielding plate is provided between the light emitter and the first photodetector, and the end of the light-shielding plate is fitted between the first optical lens and the third optical lens and protrudes from the light-emitting side lens surface of the third optical lens, thereby preventing the target scattered light and large-angle detection light from entering the first and second photodetectors.

[0061] In one selective example, the photoemitter is positioned between the first photodetector and the second photodetector. A light-shielding plate is provided between the light emitter and the first photodetector, and / or between the light emitter and the second photodetector, and the light-shielding plate is provided so as to protrude from the light-emitting side lens surface of the third optical lens.

[0062] In a second embodiment, one embodiment of the present disclosure provides a cleaning robot including a robot body and a distance measuring device provided in the first embodiment, wherein the distance measuring device is provided on the robot body.

Claims

1. A distance measuring device, It includes an optical emitter (101) and at least two photodetectors, The aforementioned optical emitter (101) is used to emit detection light. The at least two photodetectors include a first photodetector (102) and a second photodetector (103), the first photodetector (102) being used to receive a first signal light reflected by the object to be measured (100) under the action of the detection light and to output a first echo signal, the second photodetector (103) being used to receive a second signal light reflected by the object to be measured (100) under the action of the detection light and to output a second echo signal, and the distance measuring device obtaining a target distance based on the ratio of the first echo signal to the second echo signal. A distance measuring device characterized by the following features.

2. The first photodetector (102) and the second photodetector (103) are at equal distances from the object to be measured (100), The distance measuring device according to claim 1, characterized in that, within a preset distance range, the ratio of the first overlapping area to the second overlapping area has a positive or negative correlation with the distance, the first overlapping area is the overlapping area of ​​the visible region of the first photodetector (102) and the irradiation region of the photoemitter (101), and the second overlapping area is the overlapping area of ​​the visible region of the second photodetector (103) and the irradiation region of the photoemitter (101).

3. Furthermore, it includes a first optical lens (112), a second optical lens (113), a third optical lens (111), and a light-shielding plate (121), The detection light transmitted from the optical emitter (101) is emitted through the third optical lens (111), the first signal light enters the first photodetector (102) through the first optical lens (112), and the second signal light enters the second photodetector (103) through the second optical lens (113). The distance measuring device according to claim 1, wherein the light shielding plate (121) is used to prevent target scattered light from entering the first photodetector (102) and / or the second photodetector (103), and the target scattered light is scattered light formed when the detection light is irradiated onto dust on the light-emitting lens surface of the third optical lens (111).

4. The first photodetector (102) is positioned between the photoemitter (101) and the second photodetector (103). The distance measuring device according to claim 3, characterized in that a light-shielding plate (121) is provided between the first photodetector (102) and the second photodetector (103), thereby preventing the target scattered light from entering the second photodetector (103).

5. The distance measuring device according to claim 4, characterized in that the light-receiving lens surface of the first optical lens (112) and the light-receiving lens surface of the second optical lens (113) are integrally provided, and the light-shielding plate (121) is fitted into the opening between the first optical lens (112) and the second optical lens (113) from the light-exiting side.

6. The first optical lens (112) and the second optical lens (113) are provided independently of each other, and the end of the light-shielding plate (121) is fitted between the first optical lens (112) and the second optical lens (113). The distance measuring device according to claim 4, characterized in that the end of the light-shielding plate (121), the light-receiving lens surface of the first optical lens (112), and the light-receiving lens surface of the second optical lens (113) are flush, or the end of the light-shielding plate (121) protrudes from the light-receiving lens surface of the first optical lens (112).

7. Furthermore, it includes a baffle plate (120), the baffle plate (120) is provided between the light emitter (101) and the first photodetector (102), and the end of the baffle plate (120) is fitted between the first optical lens (112) and the third optical lens (111). The distance measuring device according to any one of claims 4 to 6, characterized in that the end of the baffle plate (120) is flush with the light-emitting side lens surface of the third optical lens (111), or the end of the baffle plate (120) protrudes from the light-emitting side lens surface of the third optical lens (111).

8. The distance measuring device according to claim 7, characterized in that the end of the baffle plate (120) protrudes 0.3 mm to 1 mm from the light-emitting lens surface of the third optical lens (111).

9. The first photodetector (102) is positioned between the photoemitter (101) and the second photodetector (103). The distance measuring device according to claim 3, wherein a light-shielding plate (121) is provided between the light emitter (101) and the first photodetector (102), the end of the light-shielding plate is fitted between the first optical lens (112) and the third optical lens (111), and protrudes from the light-emitting side lens surface of the third optical lens (111), thereby preventing the target scattered light and large-angle detection light from entering the first photodetector (102) and the second photodetector (103).

10. The photoemitter (101) is positioned between the first photodetector (102) and the second photodetector (103). The distance measuring device according to claim 3, wherein a light-shielding plate (121) is provided between the light emitter (101) and the first photodetector (102), and / or between the light emitter (101) and the second photodetector (103), and the light-shielding plate (121) is provided so as to protrude from the light-emitting side lens surface of the third optical lens (111).

11. A cleaning robot, comprising a robot body (200) and The distance measuring device is provided on the robot body (200), and the distance measuring device is provided on the robot body (200). A cleaning robot characterized by the following features.

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