Distance measuring device and cleaning robot
By employing a PSD-based ranging device in a cleaning robot, photocurrent data is generated by the movement of a light spot formed by a photosensitive element and a lens group. This solves the problems of high cost and inaccurate ranging of existing sensors, and achieves low-cost, high-precision ranging functionality.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-31
- Publication Date
- 2026-04-14
AI Technical Summary
Existing wall-following distance sensors for cleaning robots are either too expensive or have complex algorithms, resulting in inaccurate distance measurements and making it difficult to meet cleaning needs.
A ranging device based on the PSD principle is used. By setting at least two photosensitive elements and lens groups arranged in sequence, photocurrent data is generated by the movement of the light spot in the receiving area, and the distance is calculated by the processing module.
It reduces production costs, improves measurement accuracy, avoids ranging errors caused by the reflectivity deviation of different targets, and meets the needs of cleaning robots for wall cleaning.
Smart Images
Figure CN224112610U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of cleaning equipment technology, and in particular to a ranging device and a cleaning robot. Background Technology
[0002] Cleaning robots, as smart home appliances, are widely used in daily life. They can automatically complete some floor cleaning tasks, greatly improving the efficiency of cleaning work. By installing wall-following distance sensors on cleaning robots, they can maintain a certain distance from the wall during the cleaning process, enabling functions such as edge-following and precise obstacle avoidance. Combined with the high-speed rotation of the robot's side brushes, dust can be cleaned from wall crevices. In existing technologies, line laser wall-following sensors or position-sensitive detectors are commonly used. However, these sensors often suffer from high costs or complex structural algorithms, which are not conducive to cleaning work. Utility Model Content
[0003] This utility model provides a ranging device and a cleaning robot, which can help reduce production costs, improve measurement accuracy, and meet the needs of the cleaning robot for cleaning along walls.
[0004] In a first aspect, this utility model provides a ranging device, comprising: a light emitting unit, at least two photosensitive elements arranged sequentially, and a lens group. The light emitting unit emits infrared detection light to a target. The photosensitive elements are all located on one side of the light emitting unit and have a receiving area. The receiving area can receive the light reflected by the target under the action of the detection light, and the photosensitive element can generate photocurrent data based on the reflected light. The lens group includes a first lens and a second lens. The first lens is disposed on the light-emitting path of the light emitting unit and is used to focus the detection light onto the target. The second lens is disposed on the light-incident path of the photosensitive element and is used to focus the light reflected by the target onto the receiving area. The light reflected by the target forms a spot within the receiving area after passing through the second lens, enabling the photosensitive element to generate corresponding photocurrent data.
[0005] This invention is based on the principle of a Position Sensitive Detector (PSD). It utilizes at least two sequentially arranged photosensitive elements and a lens group, treating these photosensitive elements as a simplified PSD chip. Each photosensitive element has a receiving area. The lens group includes a first lens and a second lens. The first lens is positioned in the light-emitting path of the light emitter to focus the probe light onto the target. The second lens is positioned in the light-incident path of the photosensitive element to focus the light reflected from the target onto the receiving area. The first lens focuses the probe light emitted by the light emitter onto targets at different distances. The light reflected from these targets is then focused by the second lens onto the simplified PSD receiving area formed by the photosensitive elements. The light reflected from the target forms a spot after passing through the second lens. Based on the area and position of the spot within the receiving area, the photosensitive element generates corresponding photocurrent data. As the target moves from near to far from the photosensitive element, the spot within the simplified receiving area shifts, causing the photosensitive element to generate different photocurrent data. The distance between the ranging device and the target can be obtained based on photocurrent data and preset calculation conditions. This invention helps reduce production costs, improves measurement accuracy, and avoids the error caused by the reflectivity deviation of different targets when using ordinary infrared sensors.
[0006] According to the aforementioned embodiment of the first aspect of this utility model, the focal length of the second lens is configured such that the size of the light spot in the first direction is not greater than the width of the receiving area, and the size in the second direction is not less than the height of the receiving area. This utility model's technical solution, by configuring the focal length of the second lens so that the size of the light spot in the first direction is not greater than the width of the receiving area, and the size in the second direction is not less than the height of the receiving area, facilitates the full utilization of the light spot energy in the receiving area.
[0007] According to the aforementioned embodiment of the first aspect of this utility model, the optical axis of the second lens is set perpendicular to the arrangement direction of the photosensitive elements. When the distance between the target and the ranging device changes, the movement direction of the light spot within the receiving area is: moving along the arrangement direction of the photosensitive elements. When the distance between the target and the ranging device gradually increases, the movement direction of the light spot is: moving from the photosensitive element farther away from the light emitting part to the photosensitive element closer to the light emitting part. This utility model's technical solution can generate different light spots falling within the receiving area based on different distances between the target and the photosensitive elements. The photosensitive elements thus generate different photocurrent data. Based on the photocurrent data and preset calculation conditions, the distance between the ranging device and the target can be obtained, which helps reduce production costs, improve measurement accuracy, and avoids the error problem caused by the different reflectivity deviations of ordinary infrared sensors during ranging.
[0008] According to the aforementioned embodiment of the first aspect of this utility model, the ranging device further includes: a processing module electrically connected to a photosensitive element. Based on the area and position of the light spot falling within the receiving area, each photosensitive element generates corresponding photocurrent data. The processing module converts each photocurrent data into a corresponding voltage value and outputs a distance value corresponding to the voltage value according to preset conditions, thereby obtaining the distance between the ranging device and the target to be measured. This utility model's technical solution converts photocurrent data into corresponding voltage values through a processing module. Based on the voltage value and preset calculation conditions, the distance between the ranging device and the target to be measured can be obtained. This helps reduce production costs, improve measurement accuracy, and avoids the error problem caused by the reflectivity deviation of different targets when using ordinary infrared sensors for ranging.
[0009] According to the aforementioned embodiment of the first aspect of this utility model, the photosensitive element includes a first photosensitive element and a second photosensitive element, the first photosensitive element and the second photosensitive element are arranged sequentially along the light spot moving direction, and the photosensitive surfaces of the first photosensitive element and the second photosensitive element are located on the same plane.
[0010] According to the aforementioned embodiments of the first aspect of this utility model, the first photosensitive element and the second photosensitive element can generate a first current value and a second current value respectively based on the light reflected by the target under the action of the probe light. The processing module can convert the first current value and the second current value into corresponding voltage values respectively, calculate a first ratio based on the voltage value and preset conditions, and output the corresponding distance value based on the first ratio to obtain the distance between the ranging device and the target.
[0011] According to the aforementioned embodiments of the first aspect of this utility model, the photosensitive element includes a third photosensitive element, a fourth photosensitive element, and a fifth photosensitive element, which are arranged sequentially along the direction of light spot movement, and the photosensitive surfaces of the third photosensitive element, the fourth photosensitive element, and the fifth photosensitive element are located on the same plane.
[0012] According to the aforementioned embodiments of the first aspect of this utility model, the third, fourth, and fifth photosensitive elements can generate a third current value, a fourth current value, and a fifth current value respectively based on the light reflected by the target under the action of the probe light. The processing module can convert the third, fourth, and fifth current values into corresponding voltage values respectively, and calculate a second ratio and a third ratio based on the voltage values and preset conditions. Based on the second ratio, the third ratio, and the preset conditions, the module outputs the corresponding distance value to obtain the distance between the ranging device and the target.
[0013] According to any of the foregoing embodiments of the first aspect of this utility model, the lens group is one of a hyperbolic aspherical lens, a Fresnel lens, a common spherical lens, an aspherical lens, a freeform surface lens, and a diffractive optical element.
[0014] Secondly, embodiments of the present invention provide a cleaning robot, which includes a ranging device according to any of the foregoing embodiments of the first aspect of the present invention.
[0015] This invention relates to a cleaning robot equipped with a ranging device based on the PSD (Photosensitive Detector) principle. The device utilizes at least two sequentially arranged photosensitive elements and a lens group, treating these photosensitive elements as a simplified PSD chip. Each photosensitive element has a receiving area. The lens group includes a first lens and a second lens. The first lens is positioned in the light-emitting path of the light emitter to focus the probe light onto the target. The second lens is positioned in the light-incident path of the photosensitive element to focus the light reflected from the target onto the receiving area. The first lens focuses the probe light emitted by the light emitter onto targets at different distances. The light reflected from these targets is then focused by the second lens onto the simplified PSD receiving area formed by the photosensitive elements. The light reflected from the target forms a spot after passing through the second lens. Based on the area and position of the spot within the receiving area, the photosensitive element generates corresponding photocurrent data. As the target moves from near to far from the photosensitive element, the spot within the simplified receiving area shifts, causing the photosensitive element to generate different photocurrent data. The distance between the ranging device and the target can be obtained based on photocurrent data and preset calculation conditions. This invention helps reduce production costs, improves measurement accuracy, and avoids the error caused by the reflectivity deviation of different targets when using ordinary infrared sensors. It also helps meet the needs of cleaning robots for wall cleaning.
[0016] This utility model's technical solution uses at least two sequentially arranged photosensitive elements and a lens group to treat the at least two sequentially arranged photosensitive elements as a simplified PSD chip. It performs distance measurement based on the PSD principle, avoiding the error caused by the deviation of the reflectivity of different targets in ordinary infrared sensors during distance measurement. This helps to reduce costs, improve measurement accuracy, and meet the needs of cleaning robots for cleaning along walls. Attached Figure Description
[0017] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.
[0018] Figure 1This is a schematic diagram illustrating the measurement of a nearby target using an embodiment of the ranging device of this utility model;
[0019] Figure 2 This is a schematic diagram illustrating the measurement of a distant target using an embodiment of the ranging device of this utility model;
[0020] Figure 3 This is a schematic diagram of the light spot formed on a target at close range in an embodiment of the ranging device of this utility model;
[0021] Figure 4 This is a schematic diagram of the light spot formed by the target to be measured in one embodiment of the ranging device of this utility model;
[0022] Figure 5 This is a schematic diagram of the light spot formed on a distant target in an embodiment of the ranging device of this utility model;
[0023] Figure 6 This is a schematic diagram illustrating the triangulation principle of a PSD sensor.
[0024] Figure 7 This is an exemplary relationship curve between the output voltage of the second photosensitive element and the distance in one embodiment of the ranging device of this utility model;
[0025] Figure 8 This is an exemplary relationship curve between the output voltage of the first photosensitive element and the distance in one embodiment of the ranging device of this utility model;
[0026] Figure 9 This is an exemplary relationship curve between voltage ratio and distance in one embodiment of the ranging device of this utility model;
[0027] Figure 10 This is a schematic diagram of another embodiment of the ranging device of this utility model.
[0028] Explanation of icon numbers:
[0029] Light emitting unit-100, photosensitive element-200, lens group-300, light blocking plate-400, target under test-500;
[0030] First photosensitive element-210, second photosensitive element-220, third photosensitive element-230, fourth photosensitive element-240, fifth photosensitive element-250, first lens-310, second lens-320;
[0031] Receiving area - S1, light spot - S2, first direction - X1, second direction - Y1.
[0032] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation
[0033] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.
[0034] It should be noted that all directional indicators (such as up, down, left, right, front, back, etc.) in this utility model embodiment are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicator will also change accordingly.
[0035] Furthermore, the use of terms such as "first" and "second" in this utility model is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. Additionally, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this utility model.
[0036] This utility model provides a ranging device and a cleaning robot, which can help reduce production costs, improve measurement accuracy, and meet the needs of the cleaning robot for cleaning along walls.
[0037] like Figures 1 to 2 As shown, this embodiment of the present invention provides a ranging device, which includes: a light emitting unit 100, at least two photosensitive elements 200 arranged sequentially, and a lens group 300. The light emitting unit 100 emits infrared detection light to the target to be measured. The photosensitive elements 200 are all located on one side of the light emitting unit 100. Each photosensitive element 200 has a receiving area S1, which can receive the light reflected by the target under the action of the detection light. The photosensitive element 200 can generate photocurrent data based on the reflected light. The lens group 300 includes a first lens 310 and a second lens 320. The first lens 310 is disposed on the light output path of the light emitting unit 100 and is used to focus the detection light onto the target to be measured. The second lens 320 is disposed on the light input path of the photosensitive element 200 and is used to focus the light reflected by the target to the receiving area S1. The light reflected by the target can form a light spot S2 falling within the receiving area S1 after passing through the second lens 320, so that the photosensitive element 200 can generate corresponding photocurrent data.
[0038] This invention is based on the principle of a Position Sensitive Detector (PSD). It utilizes at least two sequentially arranged photosensitive elements 200 and a lens group 300, treating the photosensitive elements 200 as a simplified PSD chip. Each photosensitive element 200 has a receiving area S1. The lens group 300 includes a first lens 310 and a second lens 320. The first lens 310 is positioned in the light-emitting path of the light emitting unit 100 to focus the probe light onto the target. The second lens 320 is positioned in the light-incident path of the photosensitive element 200 to focus the light reflected from the target onto the receiving area S1. The first lens 310 focuses the probe light emitted by the light emitting unit 100 onto targets at different distances, and the light reflected back from these targets is then focused by the second lens 320 into the simplified PSD receiving area S1 formed by the photosensitive elements 200. The light reflected from the target passes through the second lens 320 to form a light spot S2. Based on the area and position of the light spot S2 within the receiving area S1, the photosensitive element 200 generates corresponding photocurrent data. As the target moves from a close distance to a greater distance from the photosensitive element 200, the light spot S2 within the receiving area S1 shifts, causing the photosensitive element 200 to generate different photocurrent data. Based on the photocurrent data and preset calculation conditions, the distance between the ranging device and the target can be obtained. This invention helps reduce production costs, improves measurement accuracy, and avoids the error problems caused by the varying reflectivity of different targets in ordinary infrared sensors during ranging.
[0039] In this application, the first lens 310 can shape the infrared detection light emitted by the light emitting unit 100, so that the beam has a uniform light intensity distribution. Furthermore, the emission intensity or frequency of the infrared detection light can be dynamically adjusted according to the measured distance calculated in real time.
[0040] In some embodiments, the distances between the light emitting unit 100, each photosensitive element 200, and the target 500 are all equal. For example, the central axes of the light emitting unit 100 and each photosensitive element 200 are arranged parallel to each other, and along the direction of the central axis, the light emitting surface of the light emitting unit 100 and the light incident surface of the photosensitive element 200 are flush. In this case, it can be considered that the distances between the light emitting unit 100, each photosensitive element 200, and the target 500 are all equal.
[0041] In this embodiment, the focal length of the second lens 320 is configured such that the size of the light spot S2 in the first direction is not greater than the width of the receiving area S1, and the size in the second direction is not less than the height of the receiving area S1. This invention, by configuring the focal length of the second lens 320 so that the size of the light spot S2 in the first direction is not greater than the width of the receiving area S1, and the size in the second direction is not less than the height of the receiving area S1, facilitates the full utilization of the energy of the light spot S2 by the receiving area S1.
[0042] like Figures 1 to 2 As shown, the optical axis of the second lens 320 is perpendicular to the arrangement direction of the photosensitive element 200. When the distance between the target and the ranging device changes, the light spot S2 moves in the receiving area S1 along the arrangement direction of the photosensitive element 200. When the distance between the target and the ranging device gradually increases, the light spot S2 moves from the photosensitive element 200 away from the light emitting part 100 to the photosensitive element 200 closer to the light emitting part 100. This invention can generate different light spots S2 falling within the receiving area S1 based on different distances between the target and the photosensitive element 200. The photosensitive element 200 then generates different photocurrent data. Based on the photocurrent data and preset calculation conditions, the distance between the ranging device and the target can be obtained, which helps reduce production costs, improve measurement accuracy, and avoids the error problem caused by the reflectivity deviation of different targets in ordinary infrared sensors during ranging.
[0043] In this embodiment, the ranging device further includes a processing module electrically connected to the photosensitive element 200. Based on the area and position of the light spot S2 falling within the receiving area S1, each photosensitive element 200 generates corresponding photocurrent data. The processing module converts each photocurrent data into a corresponding voltage value and outputs a distance value corresponding to the voltage value according to preset conditions, thereby obtaining the distance between the ranging device and the target. This invention converts photocurrent data into corresponding voltage values through a processing module. Based on the voltage value and preset calculation conditions, the distance between the ranging device and the target can be obtained. This helps reduce production costs, improve measurement accuracy, and avoids the error problem caused by the reflectivity deviation of different targets in ordinary infrared sensors during ranging.
[0044] Furthermore, the processing module includes a current-to-voltage conversion module and a calculation module. The current-to-voltage conversion module is electrically connected to the photosensitive element 200 and is used to convert photocurrent data into voltage values. The calculation module is used to receive voltage values, calculate voltage ratios according to preset requirements, and output the corresponding distance value based on the voltage ratios.
[0045] like Figures 1 to 2As shown, the photosensitive element 200 includes a first photosensitive element 210 and a second photosensitive element 220. The first photosensitive element 210 and the second photosensitive element 220 are arranged sequentially along the moving direction of the light spot S2, and the photosensitive surfaces of the first photosensitive element 210 and the second photosensitive element 220 are located on the same plane.
[0046] like Figures 7 to 8 As shown, the first photosensitive element 210 and the second photosensitive element 220 can generate a first current value and a second current value respectively based on the light reflected by the target under the action of the probe light. The processing module can convert the first current value and the second current value into corresponding voltage values respectively, and calculate a first ratio based on the voltage value and preset conditions. Based on the first ratio, the corresponding distance value is output to obtain the distance between the ranging device and the target. By measuring the distance between different targets 500 and the ranging device, the magnitude of the photocurrent output by the first photosensitive element 210 and the second photosensitive element 220 is obtained. After being converted into voltage values by the processing module, the voltage value V1 of the first photosensitive element 210 and the voltage value V2 of the second photosensitive element 220 are obtained.
[0047] Specifically, in one embodiment, two different colored targets 500, black and white, are used as examples.
[0048] When measuring the distance to the black target 500, the distances of the first photosensitive element 210 and the second photosensitive element 220 from the black target 500 are 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, and 60 mm, respectively. The voltage values V1 of the first photosensitive element 210 are 0.002, 0.008, 0.015, 0.023, 0.029, 0.033, 0.035, 0.036, 0.036, 0.034, and 0.033 V, respectively, and the voltage values V2 of the second photosensitive element 220 are 0.075, 0.131, 0.143, 0.11, 0.074, 0.047, 0.026, 0.014, 0.007, 0.003, and 0.001 V, respectively.
[0049] When measuring the distance to the white target 500, the distances of the first photosensitive element 210 and the second photosensitive element 220 from the white target 500 are 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, and 60 mm, respectively. The voltage values V1 of the first photosensitive element 210 are 0.106, 0.161, 0.242, 0.312, 0.369, 0.405, 0.419, 0.419, 0.408, 0.392, and 0.372 V, respectively, and the voltage values V2 of the second photosensitive element 220 are 1.069, 1.653, 1.777, 1.618, 1.158, 0.643, 0.325, 0.158, 0.077, 0.037, and 0.018 V, respectively. Figure 6As shown, based on the triangulation principle of the PSD sensor, the distance between the target 500 and the ranging device can be obtained using the following formula:
[0050] L = h * (V1 - V2) / (V1 + V2),
[0051] Where L is the distance between the target 500 and the ranging device, V1 is the voltage value of the first photosensitive element 210, V2 is the voltage value of the second photosensitive element 220, and h is a fixed coefficient (obtained based on the focal length of the first lens 310, the second lens 320, and the baseline distance).
[0052] Specifically, based on the linear relationship obtained by fitting the voltage ratio (V1-V2) / (V1+V2) with the distance, when measuring the distance to the black target 500, the voltage ratios of the first photosensitive element 210 and the second photosensitive element 220 are -0.948, -0.885, -0.810, -0.654, -0.437, -0.175, 0.148, 0.440, 0.674, 0.838, and 0.941, respectively, corresponding to distance values of 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, and 60 mm. When measuring the distance to the white target 500, the voltage ratios of the first photosensitive element 210 and the second photosensitive element 220 are -0.820, -0.822, -0.760, -0.677, -0.517, -0.227, 0.126, 0.452, 0.682, 0.828, and 0.908, respectively, corresponding to distances of 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, and 60 mm (the error is negligible). Therefore, as... Figure 9 As shown, the distance between the target 500 and the ranging device can be linearly related to the voltage ratio (V1-V2) / (V1+V2) of the first photosensitive element 210 and the second photosensitive element 220 by fitting the distance. This is beneficial for achieving a low-cost ranging function that is resistant to reflectivity interference, and avoids the problem of errors caused by ordinary infrared sensors when measuring distances due to the reflectivity deviation of different targets 500.
[0053] like Figure 10 As shown, the photosensitive element 200 includes a third photosensitive element 230, a fourth photosensitive element 240, and a fifth photosensitive element 250. The third photosensitive element 230, the fourth photosensitive element 240, and the fifth photosensitive element 250 are arranged sequentially along the moving direction of the light spot S2, and the photosensitive surfaces of the third photosensitive element 230, the fourth photosensitive element 240, and the fifth photosensitive element 250 are located on the same plane.
[0054] In this embodiment, the third photosensitive element 230, the fourth photosensitive element 240, and the fifth photosensitive element 250 can generate a third current value, a fourth current value, and a fifth current value respectively based on the light reflected by the target under the action of the detection light. The processing module can convert the third current value, the fourth current value, and the fifth current value into corresponding voltage values respectively, and calculate a second ratio and a third ratio based on the voltage values and preset conditions. Based on the second ratio, the third ratio, and the preset conditions, the corresponding distance value is output to obtain the distance between the ranging device and the target.
[0055] In this embodiment, the photocurrent output by the third photosensitive element 230, the fourth photosensitive element 240, and the fifth photosensitive element 250 is obtained by measuring the distance between different targets 500 and the ranging device. The photocurrent is then converted into voltage values by the processing module to obtain the voltage values V3 of the third photosensitive element 230, V4 of the fourth photosensitive element 240, and V5 of the fifth photosensitive element 250.
[0056] Based on the triangulation principle of the PSD sensor, the distance between the target 500 and the ranging device can be obtained using the following formula:
[0057] L = h * (M1 - M2) / (M1 + M2)
[0058] M1 = (V3 - V4) / (V3 + V4)
[0059] M2 = (V4 - V5) / (V4 + V5)
[0060] Wherein, L is the distance between the target 500 and the ranging device, V3 is the voltage value of the third photosensitive element 230, V4 is the voltage value of the fourth photosensitive element 240, V5 is the voltage value of the fifth photosensitive element 250, h is a fixed coefficient (obtained based on the focal length of the first lens 310 and the second lens 320 and the baseline distance), M1 is the voltage ratio of the third photosensitive element 230 and the fourth photosensitive element 240, and M2 is the voltage ratio of the fourth photosensitive element 240 and the fifth photosensitive element 250.
[0061] Therefore, the distance between the target 500 and the ranging device can be linearly related to the voltage ratio of the third photosensitive element 230 and the fourth photosensitive element 240 and the voltage ratio of the fourth photosensitive element 240 and the fifth photosensitive element 250 (M1-M2) / (M1+M2) by fitting the distance, which is beneficial to further improve the accuracy of ranging.
[0062] This application allows for the selection of two or three photosensitive elements 200 depending on specific needs, which helps to balance cost and ranging accuracy and meet the needs of different application scenarios.
[0063] In this embodiment, the lens group 300 is one of the following: hyperbolic aspherical lens, Fresnel lens, ordinary spherical lens, aspherical lens, freeform lens, and diffractive optical element. Preferably, a hyperbolic aspherical lens can be used.
[0064] like Figures 1 to 2 As shown, a light-blocking plate 400 is provided between the light emitting unit 100 and the photosensitive element 200. This invention, by providing a light-blocking plate 400 between the light emitting unit 100 and the photosensitive element 200, helps prevent some of the large-angle detection light emitted by the light emitting unit 100 from being received by the adjacent photosensitive element 200, thereby improving the accuracy of distance detection results. For example, the light-blocking plate 400 can be made of black light-blocking material and has a light-blocking function.
[0065] This utility model embodiment also provides a cleaning robot, which includes a ranging device according to any of the foregoing embodiments of this utility model.
[0066] like Figures 1 to 2 As shown, this embodiment of the present invention provides a ranging device, which includes: a light emitting unit 100, at least two photosensitive elements 200 arranged sequentially, and a lens group 300. The light emitting unit 100 emits infrared detection light to the target to be measured. The photosensitive elements 200 are all located on one side of the light emitting unit 100. Each photosensitive element 200 has a receiving area S1, which can receive the light reflected by the target under the action of the detection light. The photosensitive element 200 can generate photocurrent data based on the reflected light. The lens group 300 includes a first lens 310 and a second lens 320. The first lens 310 is disposed on the light output path of the light emitting unit 100 and is used to focus the detection light onto the target to be measured. The second lens 320 is disposed on the light input path of the photosensitive element 200 and is used to focus the light reflected by the target to the receiving area S1. The light reflected by the target can form a light spot S2 falling within the receiving area S1 after passing through the second lens 320, so that the photosensitive element 200 can generate corresponding photocurrent data.
[0067] This invention provides a ranging device within a cleaning robot. Based on the PSD (Photosensitive Detector) principle, the ranging device utilizes at least two sequentially arranged photosensitive elements 200 and a lens group 300, treating the photosensitive elements 200 as a simplified PSD chip. Each photosensitive element 200 has a receiving area S1. The lens group 300 includes a first lens 310 and a second lens 320. The first lens 310 is positioned in the light-emitting path of the light emitting unit 100 to focus the probe light onto the target. The second lens 320 is positioned in the light-incident path of the photosensitive element 200 to focus the light reflected from the target onto the receiving area S1. The first lens 310 focuses the probe light emitted by the light emitting unit 100 onto targets at different distances, and the light reflected back from these targets is then focused by the second lens 320 into the simplified PSD receiving area S1 formed by the photosensitive elements 200. The light reflected from the target passes through the second lens 320 to form a light spot S2. Based on the area and position of the light spot S2 within the receiving area S1, the photosensitive element 200 generates corresponding photocurrent data. As the target moves from a close distance to a greater distance from the photosensitive element 200, the light spot S2 within the receiving area S1 shifts, causing the photosensitive element 200 to generate different photocurrent data. The distance between the ranging device and the target can be obtained based on the photocurrent data and preset calculation conditions. This invention helps reduce production costs, improves measurement accuracy, and avoids the error problems caused by the reflectivity deviation of different targets in ordinary infrared sensors during distance measurement, thus meeting the needs of cleaning robots for wall cleaning.
[0068] It is understood that the cleaning robot includes a main body, and the location of the ranging device on the main body can be determined according to the actual application scenario. For example, when applied to a sweeping robot, the ranging device can be set on the side of the main body to detect the distance to the wall and control the walking path along the wall. Preferably, a dustproof structure is provided outside the ranging device, which includes a frame and a sealing device to block the interference of dust in the environment on the reception of reflected light, thereby improving the ranging accuracy. The cleaning robot can also be a mopping robot, a sweeping and mopping robot, a window cleaning robot, or other cleaning equipment; this application does not limit this.
[0069] It should be noted that the ranging device in this application needs to process the photoelectric signal of the reflected light and then calculate the distance under preset conditions. In some embodiments, the ranging device can also be regarded as a photoelectric switch. For example, by detecting the intensity and magnitude of the photoelectric signal of the light spot S2S2 formed by the reflected light falling in the receiving area S1S1, it can be determined whether the distance between the target 500 and the ranging device has reached the preset distance, so as to determine whether the ranging device needs to move closer to or further away from the target 500, which helps to reduce costs.
[0070] This utility model's technical solution uses at least two sequentially arranged photosensitive elements 200 and a lens group 300 to treat the at least two sequentially arranged photosensitive elements 200 as a simplified PSD chip. It performs distance measurement based on the PSD principle, avoiding the error problem caused by the deviation of the reflectivity of different targets in ordinary infrared sensors during distance measurement. This helps to reduce costs, improve measurement accuracy, and meet the needs of cleaning robots for cleaning along walls.
[0071] The above description is only a preferred embodiment of the present utility model and does not limit the patent scope of the present utility model. All equivalent structural transformations made under the inventive concept of the present utility model using the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present utility model.
Claims
1. A ranging device, characterized in that, The ranging device includes: The light emitting unit is used to emit infrared detection light to the target to be measured; At least two photosensitive elements are arranged sequentially, each located on one side of the light emitting section. Each photosensitive element has a receiving area capable of receiving light reflected from the target under the action of the probe light. The photosensitive element can generate photocurrent data based on the reflected light. The lens group includes a first lens and a second lens. The first lens is disposed on the light-emitting path of the light-emitting part and is used to focus the probe light onto the target to be tested. The second lens is disposed on the light-incident path of the photosensitive element and is used to focus the light reflected from the target to be tested onto the receiving area. The light reflected from the target to be tested can form a light spot falling on the receiving area after passing through the second lens, so that the photosensitive element can generate corresponding photocurrent data.
2. The ranging device as described in claim 1, characterized in that, The focal length of the second lens is configured such that the size of the light spot in the first direction is not greater than the width of the receiving area, and the size in the second direction is not less than the height of the receiving area.
3. The ranging device as described in claim 2, characterized in that, The optical axis of the second lens is perpendicular to the arrangement direction of the photosensitive element. When the distance between the target to be measured and the ranging device changes, the light spot moves in the receiving area along the arrangement direction of the photosensitive element. As the distance between the target and the ranging device gradually increases, the direction of movement of the light spot is: from the photosensitive element that is far away from the light emitting part to the photosensitive element that is close to the light emitting part.
4. The ranging device as described in claim 2, characterized in that, The ranging device further includes: The processing module is electrically connected to the photosensitive element. Based on the area and position of the light spot falling within the receiving area, each photosensitive element can generate corresponding photocurrent data. The processing module can convert each photocurrent data into a corresponding voltage value and output a distance value corresponding to the voltage value according to preset conditions to obtain the distance between the ranging device and the target to be measured.
5. The ranging device as described in claim 4, characterized in that, The photosensitive element includes a first photosensitive element and a second photosensitive element, which are arranged sequentially along the direction of light spot movement, and the photosensitive surfaces of the first photosensitive element and the second photosensitive element are located on the same plane.
6. The ranging device as described in claim 5, characterized in that, The first photosensitive element and the second photosensitive element can generate a first current value and a second current value respectively based on the light reflected by the target under the action of the probe light. The processing module can convert the first current value and the second current value into corresponding voltage values respectively, and calculate a first ratio based on the voltage value and preset conditions. Based on the first ratio, the corresponding distance value is output to obtain the distance between the ranging device and the target.
7. The ranging device as described in claim 4, characterized in that, The photosensitive element includes a third photosensitive element, a fourth photosensitive element, and a fifth photosensitive element. The third photosensitive element, the fourth photosensitive element, and the fifth photosensitive element are arranged sequentially along the direction of light spot movement, and the photosensitive surfaces of the third photosensitive element, the fourth photosensitive element, and the fifth photosensitive element are located on the same plane.
8. The ranging device as described in claim 7, characterized in that, The third, fourth, and fifth photosensitive elements can generate a third current value, a fourth current value, and a fifth current value respectively based on the light reflected by the target under the action of the probe light. The processing module can convert the third, fourth, and fifth current values into corresponding voltage values, and calculate a second ratio and a third ratio based on the voltage values and preset conditions. Based on the second ratio, the third ratio, and the preset conditions, the module outputs the corresponding distance value to obtain the distance between the ranging device and the target.
9. The ranging device according to any one of claims 1 to 8, characterized in that, The lens group is one of the following: hypercurvature aspherical lens, Fresnel lens, ordinary spherical lens, aspherical lens, freeform surface lens, and diffractive optical element.
10. A cleaning robot, characterized in that, The cleaning robot includes a ranging device as described in any one of claims 1 to 9.