Method for identifying transparent, semitransparent and small-size objects and elevator light curtain

Abstract

The invention relates to the technical field of elevator light curtains, in particular to a method for identifying transparent, semitransparent and small-size objects and an elevator light curtain. A plurality of first transmitting tubes and a plurality of first receiving tubes are arranged at the TX end of the light curtain, a plurality of second receiving tubes are arranged at the RX end of the light curtain, the first transmitting tubes and the first receiving tubes are installed on the same side, infrared rays of reflection and diffuse reflection are utilized, small-size, transparent and semitransparent objects which are not easy to detect are easy to detect, and the detection accuracy is improved. According to the elevator light curtain, through data collection and analysis of a laboratory, the characteristics of common interference information are analyzed, multiple judgment requirements such as the difference value of voltage values, the variation amplitude of the voltage values and the difference of voltage average values under the corresponding distance of detected voltage values are applied, interference signals are eliminated, and the accuracy of the elevator light curtain is improved. Transparent, semitransparent and small-size objects can be accurately judged, and the safety of elevator operation is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of elevator light curtains, and in particular to a method for identifying transparent, semi-transparent and small-volume objects and an elevator light curtain. Background Art

[0002] Elevator light curtain is an elevator door safety protection device made using the principle of photoelectric sensing, used to protect the safety of people and objects entering and leaving the elevator.

[0003] The door closing protection device generally adopts an infrared light curtain, which is composed of a transmitting component and a receiving component. The transmitting end transmits an infrared beam to the receiving end to receive the infrared beam. According to 5.3.6.2.2.1 of GB / T 7588.1-2020: 1. The protective device (such as light curtain) can at least cover the area 25mm to 1600mm above the car sill.

[0004] 2. The protection device should be able to detect obstacles with a diameter of not less than 50mm.

[0005] The elevator light curtains currently on the market generally cannot detect 100% of obstacles smaller than 50mm, and cannot identify transparent or translucent objects.

[0006] Patent CN216918247U discloses an elevator light curtain that can detect transparent objects. Several infrared receiving tubes are installed at the TX end of the light curtain to receive reflected signals and detect transparent objects to avoid safety accidents. However, this method still has a more serious problem. The filter strip at the RX end of the elevator light curtain and the side of the elevator door are opposite to the TX end of the elevator light curtain. When the door is closed, there will inevitably be reflected infrared light, which will definitely cause misjudgment. It is difficult to distinguish whether it is the reflection of the filter strip, elevator door, etc. belonging to the environment or the reflection of transparent or translucent objects. Therefore, this method needs to be further optimized. Summary of the invention

[0007] The problem solved by the present invention is to solve the problem of low detection rate of obstacles less than 50mm and easy misjudgment when identifying transparent and semi-transparent objects in the prior art, and to provide a special elevator light curtain and a method for identifying transparent, semi-transparent and small-volume objects.

[0008] The present invention is implemented by the following technical scheme: a method for identifying transparent, translucent, and small-volume objects, wherein the elevator light curtain used comprises a light curtain TX end and a light curtain RX end, The light curtain TX end is provided with a plurality of first transmitting tubes and a plurality of first receiving tubes, each first receiving tube cooperates with at least one first transmitting tube to form a reflection signal group, and a light blocking structure is provided at each of the plurality of first receiving tubes; The light curtain RX end is provided with a plurality of second receiving tubes, each of which cooperates with at least one first transmitting tube to form a corresponding signal group; During the elevator door closing process, the elevator light curtain starts scanning, and the reflection signal group and the shooting signal group work at the same time. That is, when the first transmitting tube emits infrared rays, the corresponding first receiving tube and the second receiving tube are turned on at the same time for signal detection, and the following judgments are made: Determine 1 whether the second receiving tube cannot receive the infrared signal. If the result is yes, it is determined that there is an obstruction. If the result is no, proceed to determination 2. Determine 2: whether all first receiving tubes have no signal. If the result is yes, it is determined that there is no obstruction. If the result is no, proceed to determine 3; Determine 3 whether only part of the first receiving tubes receive the signal. If the result is yes and the signal strength is higher than the minimum signal strength that the first receiving tube can accept, it is determined that there is an obstruction. If the result is yes, but the signal strength is only the minimum signal strength that the first receiving tube can accept, it is determined that there is no obstruction. If the result is no, proceed to determine 4. Judgment 4: Make judgments through one or more of the following three methods: Determine whether 4.1 satisfies: U a -b1<U i <U a+ b1, where U i is the voltage received by any first receiving tube in this round of scanning, U a is the average value of all first receiving tube voltages in this round of scanning, and b1 is the set first voltage allowable error; Determine whether 4.2 satisfies: U i -b2<U i+1 <U i +b2, where U i is the voltage received by any first receiving tube in this round of scanning, U i+1 Yes with U i The voltage received by the first receiving tube adjacent to the corresponding first receiving tube, b2 is the set second voltage allowable error; Determine whether 4.3 satisfies: U c -b3<U a <U c +b3, where U a is the actual average value of the voltage of all first receiving tubes in this round of scanning. During the scanning process, the distance between the light curtains is detected. U c is the theoretical average value of all first receiving tube voltages at the light curtain distance, and b3 is the set third voltage allowable error; If the conditions are met, it is determined that there is no obstruction. If the conditions are not met, it is determined that there is a transparent obstruction.

[0009] Furthermore, the data b1, b2, b3, U c All obtained from the laboratory: In the laboratory, the elevator environment is simulated, the light curtain TX end and the light curtain RX end are installed on the elevator door, and no shielding is set between the light curtain TX end and the light curtain RX end. Multiple rounds of scanning are performed to collect the voltage of all the first receiving tubes in the multiple rounds of scanning, that is, to collect the reflected light signal data from the filter strip at the light curtain RX end and the elevator door frame. By analyzing the collected data, b1, b2, b3, and U are obtained. c , recorded in the MCU's memory.

[0010] Furthermore, when the first voltage allowable error b1 is obtained through analysis, the following method is used: The voltage data from the first first receiving tube to the last first receiving tube in each round is collected, the average value of the voltage data is calculated, and then the maximum difference between the voltage data of all first receiving tubes in this round and the average voltage value of this round is calculated, and the maximum value of the maximum difference of multiple rounds is selected and multiplied by the set coefficient and recorded as b1.

[0011] Further, when the second voltage allowance b2 is obtained through analysis, the following method is adopted: The voltage data from the first first receiving tube to the last first receiving tube in each round is collected, the voltage difference between two adjacent first receiving tubes is calculated, the maximum value of the voltage difference in each round is calculated, and the maximum value of the voltage difference in multiple rounds is selected and multiplied by the set coefficient and recorded as b2.

[0012] Further, the third voltage tolerance b3 and U c , use the following method: Detect the distance between elevator light curtains, U c is the average value of all the first receiving tube voltages at this distance. Adjust the distance between the elevator light curtains to obtain U c The relationship between the distance to the light curtain; The voltage difference between the first receiving tube and the last first receiving tube in each round of scanning at the same distance is collected, and the maximum value of the voltage difference in multiple rounds of scanning is selected and multiplied by the set coefficient and recorded as b3.

[0013] Furthermore, during the laboratory data collection, the light curtain is adjusted multiple times during multiple rounds of scanning, and the adjustment methods include one or more of the following: Adjust the distance between the elevator light curtain TX end and the light curtain RX end; Adjust the emission intensity of the first transmitting tube at the TX end of the elevator light curtain; Adjust the horizontal tolerance between the elevator light curtain TX end and the light curtain RX end; Adjust the longitudinal tolerance between the elevator light curtain TX end and the light curtain RX end; Adjust the horizontal allowable angle between the elevator light curtain TX end and the light curtain RX end; Adjust the longitudinal allowable angle between the elevator light curtain TX end and the light curtain RX end; Adjust the cleanliness of the elevator light curtain filter strip and elevator door frame.

[0014] Another aspect of the present invention provides an elevator light curtain, comprising a processor and a memory, wherein the memory stores at least one instruction, and the instruction is executed by the processor, so that the elevator light curtain executes the method for the elevator light curtain to identify transparent, translucent, and small-volume objects.

[0015] Furthermore, the light-blocking structure itself or the combination of the light-blocking structure and the circuit board where the first receiving tube is located forms a cavity for accommodating the first receiving tube, and the cavity is only provided with a narrow and long opening toward the filter strip, and the vertical cross-section of the cavity is a trumpet shape that is larger on the outside and smaller on the inside, and the light-blocking structure extends forward to the filter strip.

[0016] Furthermore, the inner wall of the light-shielding structural component is provided with a reflective coating.

[0017] Furthermore, the trumpet-shaped curved surface or inclined surface of the inner wall of the light-shielding structural component is provided with a reflective coating, and the left and right side surfaces of the inner wall of the light-shielding structural component are not provided with a reflective coating.

[0018] The beneficial effects of the present invention are: 1. The present invention installs the first transmitting tube and the first receiving tube on the same side and utilizes reflected and diffusely reflected infrared rays to make it easy to detect small, transparent, and semi-transparent objects that are difficult to detect, thereby improving the functionality of the elevator light curtain.

[0019] 2. The present invention collects and analyzes the data in the laboratory, analyzes the characteristics of common interference information, and uses multiple judgment requirements, such as the difference in voltage values, the amplitude of voltage change, the difference in the average voltage value under the corresponding distance of the detection voltage value, etc., to eliminate interference signals, and can accurately judge transparent, translucent, and small-volume objects, thereby improving the safety of elevator operation.

[0020] 3. The elevator light curtain in the present invention adds a light-blocking structure at the TX end of the light curtain, and its cavity is only provided with a narrow and long opening facing the filter strip. The vertical cross-section of the cavity is a trumpet-shaped one that is large outside and small inside. The light-blocking structure extends forward to the filter strip, which can prevent the first receiving tube from directly receiving the infrared reflected from the inner surface of the filter strip. The narrow and long opening can expand the angle of light entering from the vertical direction and reduce the angle of light entering from the horizontal direction, which can avoid interference in the horizontal direction. For example, when the elevator is fully loaded, the clothes of people near the door are easy to reflect infrared rays. If the horizontal angle is large, it is easy to make a misjudgment. Therefore, the elevator light curtain of the present invention has a low misjudgment rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a scanning diagram of a conventional elevator light curtain; Figure 2 This is a structural diagram of the elevator light curtain of the present invention; Figure 3 It is a judgment logic diagram of the method for identifying transparent, semi-transparent and small-volume objects according to the present invention; Figure 4 This is a schematic diagram of Embodiment 1 of the present invention; Figure 5 This is a schematic diagram of Embodiment 2 of the present invention; Figure 6 This is a schematic diagram of Embodiment 3 of the present invention; Figure 7 This is a schematic diagram of Embodiment 4 of the present invention; Figure 8 This is a schematic diagram of Embodiment 5 of the present invention; Fig. 9 This is a schematic diagram of Embodiment 6 of the present invention; Fig.10 This is a schematic diagram of Embodiment 7 of the present invention; Fig.11 This is a schematic diagram of Embodiment 8 of the present invention; Fig.12 A schematic diagram of the elevator light curtain according to the present invention identifying a small-volume object; Fig.13 This is a partial enlarged view of the TX end of the light curtain; Fig.14 for Fig.13 Middle AA section view.

[0022] In the figure: 100 is the TX end of the light curtain; 101 is the first transmitting tube; 102 is the first receiving tube; 103 is the light blocking structure; 200 is the RX end of the light curtain; 201 is the second receiving tube. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] The infrared light curtain is composed of a transmitting end (ie, TX end) and a receiving end (ie, RX end). The TX end is composed of a transmitting tube, a control unit (MCU), a switching switch, etc.; the RX end is composed of a receiving lamp, a switching circuit, an amplifying circuit, an MCU, etc. When the infrared light beam emitted by the transmitting tube at the TX end is received by the corresponding receiving tube at the RX end, the connection between the transmitting tube and the receiving tube is called a light beam. The denser the light beam coverage, the stronger the detection sensitivity, and the scarcer the light beam, the worse the detection sensitivity. In order to improve the detection capability, a combination of parallel light beams and cross light beams is used for scanning (such as Figure 1 As shown in the figure). Among them, 3 transmit and 3 receive are parallel beams, while 3 transmit and 1 receive, 3 transmit and 2 receive, 3 transmit and 4 receive, and 3 transmit and 5 receive are cross beams. Usually, there are 36 transmitting tubes at the TX end, and the corresponding RX end has 36 receiving tubes. The beam scanning has the following angles: tube 1 on the TX end transmits, tube 1 on the RX end receives (hereinafter referred to as 1 transmit and 1 receive), 2 transmit and 2 receive..., 36 transmit and 36 receive. The second scanning angle is 1 transmit 2 receive, 2 transmit 3 receive, 3 transmit 4 receive..., 35 transmit 36 ​​receive; the third scanning angle is 1 transmit 3 receive, 2 transmit 4 receive..., 34 transmit 36 ​​receive; the fourth scanning angle is 2 transmit 1 receive, 3 transmit 2 receive..., 36 transmit 35 receive; the fifth scanning angle is 3 transmit 1 receive, 4 transmit 2 receive..., 36 transmit 34 receive. Each scanning angle from No. 1 to No. 36 is a cycle, and each cycle is about 45 ms. Therefore, the residual effect of seconds can draw a beam diagram of the five angles existing "on the same screen", as shown in Figure 2, which shows all the beams displayed. The infrared beam is emitted by the transmitting end to the receiving end for reception and identification, thus forming a cross beam network between the transmitting and receiving ends. However, it is not enough to detect transparent, semi-transparent, and small objects.

[0025] The elevator light curtain used in the present invention is the same as the conventional elevator light curtain, including a light curtain TX end 100 and a light curtain RX end 200. The light curtain TX end 100 is provided with a plurality of first transmitting tubes 101 and a plurality of first receiving tubes 102, each first receiving tube 102 cooperates with at least one first transmitting tube 101 to form a reflection signal group, and a plurality of the first receiving tubes 102 are provided with light-blocking structural members 103, and the light-blocking structural members 103 prevent the first receiving tubes 102 from directly receiving the signals of the first transmitting tubes 101; the reflection signal group can adopt 1 scanning angle, i.e., 1 transmit and 1 receive, 2 transmit and 2 receive...36 transmit and 36 receive, or adopt multiple scanning angles similar to conventional scanning, the second scanning angle is 1 transmit and 2 receive, 2 transmit and 3 receive, 3 transmit and 4 receive..., 35 transmit and 36 receive; the third scanning angle is 1 transmit and 3 receive, 2 transmit and 4 receive..., 34 transmit and 36 receive; the fourth scanning angle is 2 transmit and 1 receive, 3 transmit and 2 receive..., 36 transmit and 35 receive; the fifth scanning angle is 3 transmit and 1 receive, 4 transmit and 2 receive, Receive..., 36 transmit and 34 receive, except that the transmission and reception are at the same TX end of the light curtain.

[0026] The light curtain RX end 200 is provided with a plurality of second receiving tubes 201, each second receiving tube 201 cooperates with at least one first transmitting tube 101 to form a corresponding signal group, and conventional scanning can be performed; During the elevator door closing process, the elevator light curtain starts scanning, and the reflected signal group and the transmitted signal group work at the same time, that is, when the first transmitting tube 101 emits infrared rays, the corresponding first receiving tube 102 and the second receiving tube 201 are turned on at the same time for signal detection, and the following judgment is made: Determination 1: whether the second receiving tube 201 cannot receive the infrared signal. If the result is yes, it means that an object blocks the route of the corresponding signal group, and it is determined that there is an obstruction. If the result is no, determination 2 is performed; Determine 2, whether all the first receiving tubes 102 have no signal, if the result is yes, it means that there is no object blocking or reflecting the signal, then it is determined that there is no obstruction, if the result is no, then proceed to determine 3; Determine 3 whether only part of the first receiving tubes 102 receive the signal. If the result is yes and the signal strength is higher than the minimum signal strength that the first receiving tube 102 can accept, it is determined that there is an obstruction. If the result is yes, but the signal strength is only the minimum signal strength that the first receiving tube 102 can accept, it is determined that there is no obstruction. If the result is no, determine 4. Due to the existence of the elevator door frame and the filter strip, these two can reflect and diffusely reflect the infrared light emitted by the first transmitting tube 101. During the elevator door closing process, when the distance is less than a certain distance, the diffuse reflection signal is strong enough to enable the first receiving tube 102 to successfully detect it. However, at the critical position of the distance, some of the first receiving tubes 102 will have signals, while some of the first receiving tubes 102 will not have signals. However, the signal strength is the first The minimum signal strength that a receiving tube 102 can receive, so a judgment condition is added (and the signal strength is higher than the minimum signal strength that the first receiving tube 102 can receive) to eliminate the interference caused by the critical position. When the diffusely reflected infrared rays of a small-volume object are recognized by the first receiving tube 102, the signal strength of the first receiving tube 102 close to the small-volume obstruction is higher, and the signal strength of the first receiving tube 102 far away from the small-volume obstruction is lower. The signal strength of the first receiving tube 102 is judged by the voltage of the first receiving tube 102. Therefore, when the second receiving tubes 201 all receive infrared signals, some of the first receiving tubes 102 receive signals, and the signal strength is higher than the minimum signal strength that the first receiving tube 102 can receive, it is easy to judge that there is a small-volume obstruction.

[0027] Judgment 4: Make judgments through one or more of the following three methods: Determine whether 4.1 satisfies: U a -b1<U i <U a+ b1, where U i is the voltage received by any first receiving tube 102 in this round of scanning, U a is the average voltage of all the first receiving tubes 102 in this round of scanning, and b1 is the set allowable error of the first voltage. Theoretically, the infrared intensities received by the thirty-six first receiving tubes 102 from the elevator door frame and the diffuse reflection of the filter strip are almost the same and will not deviate too much from the average value. Therefore, the voltage average value is used to judge whether the voltage has a sudden change. If there is a sudden change, it indicates that there is an obstruction reflecting the infrared signal, which may be a small, transparent or translucent object.

[0028] Determine whether 4.2 satisfies: U i -b2<U i+1 <U i +b2, where U i is the voltage received by any first receiving tube 102 in this round of scanning, U i+1 Yes with U iThe voltage received by the adjacent first receiving tube 102 of the corresponding first receiving tube 102, b2 is the set second voltage allowable error; theoretically, when the elevator light curtain is installed, the light curtain TX end 100 and the light curtain RX end 200 have a certain angle, so the infrared intensity received by the thirty-six first receiving tubes 102 from the elevator door frame and the diffuse reflection of the filter strip increases or decreases, and the increase and decrease range is limited. Through the formula U i -b2<U i+1 <U i +b2, the infrared intensity change of the adjacent first receiving tubes 102 can be distinguished. If the change is large, it indicates that a small, transparent or semi-transparent object may appear.

[0029] Determine whether 4.3 satisfies: U c -b3<U a <U c +b3, where U a is the actual average voltage of all first receiving tubes 102 in this round of scanning. During the scanning process, the distance between the light curtains is detected. c is the theoretical average voltage of all first receiving tubes 102 at the light curtain distance, and b3 is the set third voltage allowable error; theoretically, the closer the light curtain distance is, the higher the infrared intensity received by the first receiving tube 102 from the elevator door frame and the diffuse reflection of the filter strip is, and the higher the voltage is. However, at the same distance, the average voltage should not be much different. If a small, transparent, or semi-transparent object appears, the reflected infrared will be enhanced, and the average voltage value will be greater than the theoretical value at the distance. Therefore, through the formula U c -b3<U a <U c +b3 can also determine whether there are small, transparent or translucent objects.

[0030] In practical applications, the data b1, b2, b3, U c All obtained from the laboratory: In the laboratory, the elevator environment is simulated, the light curtain TX end 100 and the light curtain RX end 200 are installed on the elevator door, and no shielding is set between the light curtain TX end 100 and the light curtain RX end 200. Multiple rounds of scanning are performed to collect the voltages of all first receiving tubes 102 in the multiple rounds of scanning, that is, to collect the reflected light signal data from the filter strip of the light curtain RX end 200 and the elevator door frame, and obtain b1, b2, b3, and U through analysis of the collected data. c , recorded in the MCU's memory.

[0031] In practical applications, when analyzing and obtaining the first voltage allowable error b1, the following method is used: The voltage data from the first first receiving tube 102 to the last first receiving tube 102 in each round are collected, the average value of the voltage data is calculated, and then the maximum difference between the voltage data of all first receiving tubes 102 in this round and the average voltage value of this round is calculated, and the maximum value of the maximum difference of multiple rounds is selected and multiplied by the set coefficient and recorded as b1. The set coefficient is selected based on laboratory experience and implementation results, and it can meet the low false detection rate and low missed detection rate.

[0032] In practical applications, when the second voltage allowance b2 is obtained through analysis, the following method is used: The voltage data from the first first receiving tube 102 to the last first receiving tube 102 in each round is collected, the voltage difference between two adjacent first receiving tubes 102 is calculated, the maximum value of the voltage difference in each round is calculated, and the maximum value of the voltage difference in multiple rounds is selected and multiplied by the set coefficient and recorded as b2. The set coefficient is selected based on laboratory experience and implementation results, and it can meet the requirements of low false detection rate and low missed detection rate.

[0033] In practical applications, the third voltage allowable error b3 and U c , use the following method: To detect the distance between elevator light curtains, the distance can be measured by distance sensor or light curtain itself through RSSI ranging principle, which will not be described here. c is the average voltage of all first receiving tubes 102 at this distance. Adjust the distance between the elevator light curtains to obtain U c The relationship between the distance to the light curtain; The voltage difference between the first receiving tube 102 and the last first receiving tube 102 in each round of scanning at the same distance is collected, and the maximum value of the voltage difference in multiple rounds of scanning is selected and multiplied by the set coefficient and recorded as b3. The set coefficient is selected based on laboratory experience and implementation results to meet low false detection rate and low missed detection rate.

[0034] In actual applications, during the laboratory data collection, the light curtain is adjusted multiple times during multiple rounds of scanning. The adjustment methods include one or more of the following: Adjust the distance between the elevator light curtain TX end and the light curtain RX end 200. The light curtain distance is directly related to the infrared intensity of the elevator door frame and the diffuse reflection of the filter strip. Adjust the distance between the elevator light curtains and perform multiple rounds of detection to obtain U c The relationship between the distance to the light curtain; Adjust the emission intensity of the first transmitting tube 101 at the TX end of the elevator light curtain; the emission intensity of the first transmitting tube 101 is directly related to the infrared intensity of the diffuse reflection of the elevator door frame and the filter strip, and affects the intensity of the diffuse reflection signal when small, transparent, or translucent objects appear; Adjust the horizontal tolerance between the elevator light curtain TX end and the light curtain RX end 200, and take the horizontal tolerance generated during installation into account; Adjust the longitudinal tolerance between the elevator light curtain TX end and the light curtain RX end 200, and take the longitudinal tolerance generated during installation into account; Adjust the horizontal allowable angle between the elevator light curtain TX end and the light curtain RX end 200, and take the horizontal allowable angle generated during installation into account; Adjust the longitudinal allowable angle between the elevator light curtain TX end and the light curtain RX end 200. The infrared intensity received by the thirty-six first receiving tubes 102 from the elevator door frame and the diffuse reflection of the filter strip increases or decreases. The amplitude of the signal change is most related to the longitudinal allowable angle. The horizontal allowable angle generated during installation needs to be taken into account. Adjust the cleanliness of the elevator light curtain filter strip and the elevator door frame. The cleanliness of the elevator light curtain filter strip and the elevator door frame will also affect the infrared intensity of the elevator filter strip and the elevator diffuse reflection. Therefore, the cleanliness of the elevator light curtain filter strip and the elevator door frame needs to be taken into account.

[0035] When testing data, taking the above contents into consideration can truly simulate the actual working conditions of the elevator and effectively reduce the probability of false detection and missed detection.

[0036] Below we simulate the scenario based on several examples: Embodiment 1, as Figure 4 As shown, in the middle are the normal scanning beams of the light curtain TX end 100 and the light curtain RX end 200, on the left is the potential diagram of the first receiving tube 102, and on the right is the potential diagram of the second receiving tube 201. At this time, there is no obstruction, the elevator doors are far apart, and the filter strips and the elevator door frame have weak reflections. Therefore, all the second receiving tubes 201 have signals, and all the first receiving tubes 102 have no signals, which meets the condition of judgment 2 and there is no obstruction.

[0037] Embodiment 2, as Figure 5 As shown, in the middle are the conventional scanning beams of the light curtain TX end 100 and the light curtain RX end 200, on the left is the potential diagram of the first receiving tube 102, and on the right is the potential diagram of the second receiving tube 201. At this time, there is a small-volume obstruction, which is just in the blind spot of the conventional scanning beam, so all the second receiving tubes 201 have signals, the elevator doors are far apart, and the filter strips and the elevator door frames have weak reflections, so most of the first receiving tubes 102 have no signals, and the first receiving tubes 102 close to the small-volume obstruction have signals. The closer the distance, the stronger the signal. The first receiving tube 102 with sequence number 3 in the figure is closest to the obstruction, so the signal is the strongest. Through the judgment condition of judgment 3, all the second receiving tubes 201 have no signals, and some of the first receiving tubes 102 have signals, then it is judged that there is an obstruction.

[0038] Embodiment three, as Figure 6As shown, in the middle are the conventional scanning beams of the light curtain TX end 100 and the light curtain RX end 200, on the left is the potential diagram of the first receiving tube 102, and on the right is the potential diagram of the second receiving tube 201. At this time, there is a vertical transparent obstruction, and the conventional scanning beam can penetrate the transparent obstruction, so all the second receiving tubes 201 have signals. The elevator doors are far apart, and the filter strips and the elevator door frames have weak reflections, so most of the first receiving tubes 102 have no signals, and the first receiving tubes 102 close to the transparent glass have signals. According to the judgment condition of judgment 3, all the second receiving tubes 201 have no signals, and some of the first receiving tubes 102 have signals, then it is judged that there is an obstruction.

[0039] Embodiment 4, as Figure 7 As shown, in the middle are the normal scanning (black) and reflected (red) light beams of the light curtain TX end 100 and the light curtain RX end 200, on the left is the potential diagram of the first receiving tube 102, and on the right is the potential diagram of the second receiving tube 201. At this time, there is no obstruction, and the second receiving tubes 201 all have signals. The first receiving tubes 102 can detect the infrared reflected by the elevator door frame and the filter strip. All first receiving tubes 102 have signals, and the signals are relatively uniform. Therefore, the process of judgment 4 is entered. If the judgment condition of 4.1 is adopted, the signal is relatively uniform and can meet U a -b1<U i <U a+ b1, if the judgment condition of 4.2 is adopted, then the signal has no increasing or decreasing trend and can satisfy U i -b2<U i+1 <U i +b2, if the judgment condition of 4.3 is adopted, the average value of the voltage is consistent with the theoretical value, so it can be judged that there is no obstruction.

[0040] Embodiment 5, as Figure 8 As shown, in the middle are the conventional scanning (black) and reflected (red) beams of the light curtain TX end 100 and the light curtain RX end 200, on the left is the potential diagram of the first receiving tube 102, and on the right is the potential diagram of the second receiving tube 201. At this time, there is a small-volume obstruction, which is just in the blind spot of the conventional scanning beam. The second receiving tube 201 has a signal, and the first receiving tube 102 can detect the infrared reflected by the elevator door frame and the filter strip. All first receiving tubes 102 have signals, and the first receiving tube 102 close to the small-volume obstruction has a signal. Due to receiving diffusely reflected infrared rays, the closer the distance, the stronger the signal, and the process of judgment 4 is entered. If the judgment condition of 4.1 is adopted, the difference between the maximum voltage and the minimum voltage is too large, and U cannot be satisfied. a -b1<U i <U a+ b1, if the judgment condition of 4.2 is adopted, the voltage variation of the first receiving tube 102 near the small-volume shielding object is large and cannot meet the Ui -b2<U i+1 <U i +b2, if the judgment condition of 4.3 is adopted, the average value of the voltage is higher than the theoretical value, so it can be judged that there is an obstruction.

[0041] Embodiment six, as Fig. 9 As shown, in the middle are the conventional scanning (black) and reflected (red) beams of the light curtain TX end 100 and the light curtain RX end 200, on the left is the potential diagram of the first receiving tube 102, and on the right is the potential diagram of the second receiving tube 201. At this time, there is a vertical transparent shielding object, and the conventional scanning beam can penetrate the transparent shielding object, so all the second receiving tubes 201 have signals, and the first receiving tube 102 can detect the infrared reflected by the elevator door frame and the filter strip. All the first receiving tubes 102 have signals, and the first receiving tube 102 close to the transparent shielding object has a signal. Due to receiving diffusely reflected infrared rays, the signal is stronger than the signal strength reflected by the elevator door frame and the filter strip. Looking at the potential diagram on the left, there are two gradients, and the process of judgment 4 is entered. If the judgment condition of 4.1 is adopted, the difference between the maximum voltage and the minimum voltage is too large, and U cannot be satisfied. a -b1<U i <U a+ b1, if the judgment condition of 4.2 is adopted, the voltage variation of the first receiving tube 102 near the edge of the transparent shield is large and cannot meet the U i -b2<U i+1 <U i +b2, if the judgment condition of 4.3 is adopted, the average value of the voltage is higher than the theoretical value, so it can be judged that there is an obstruction.

[0042] Embodiment seven, as Fig.10 As shown, in the middle are the conventional scanning (black) and reflected (red) beams of the light curtain TX end 100 and the light curtain RX end 200, on the left is the potential diagram of the first receiving tube 102, and on the right is the potential diagram of the second receiving tube 201. At this time, there is an inclined transparent shielding object, and the conventional scanning beam can penetrate the transparent shielding object, so all the second receiving tubes 201 have signals, and the first receiving tubes 102 can detect the infrared reflected by the elevator door frame and the filter strip. All the first receiving tubes 102 have signals, and the first receiving tubes 102 close to the transparent shielding object have signals. Due to receiving diffusely reflected infrared rays, the signal is stronger than the signal strength reflected by the elevator door frame and the filter strip, and because the transparent shielding object is inclined, the closer the first receiving tube 102 is to the transparent shielding object, the stronger the signal. Looking at the potential diagram on the left, some voltage values ​​are decreasing, and some voltage values ​​are flat, entering the process of judgment 4. If the judgment condition of 4.1 is adopted, the difference between the maximum voltage and the minimum voltage is too large, and U a -b1<U i <Ua+ b1, if the judgment condition of 4.2 is adopted, the voltage variation of the first receiving tube 102 corresponding to the height of the inclined transparent shielding object is large and cannot meet the U i -b2<U i+1 <U i +b2, if the judgment condition of 4.3 is adopted, the average value of the voltage is higher than the theoretical value, so it can be judged that there is an obstruction.

[0043] Embodiment eight, as Fig.11 As shown, in the middle are the normal scanning (black) and reflected (red) beams of the light curtain TX end 100 and the light curtain RX end 200, on the left is the potential diagram of the first receiving tube 102, and on the right is the potential diagram of the second receiving tube 201. At this time, there is no obstruction, but the light curtain has an angle due to installation, which is within the longitudinal allowable angle range, so all the second receiving tubes 201 have signals, and all the first receiving tubes 102 have signals, and the signal strength decreases. If the judgment condition of 4.1 is adopted, since it meets the longitudinal allowable angle requirements and the angle is limited, although the voltage decreases, the difference between the maximum voltage and the minimum voltage is not large, which can meet U a -b1<U i <U a+ b1, if the judgment condition in 4.2 is adopted, the voltage variation of the first receiving tube 102 is small and can meet the U i -b2<U i+1 <U i +b2, if the judgment condition of 4.3 is adopted, the average value of voltage at this distance is the theoretical value U c It is within the range of ±b3, so it can be judged that there is no obstruction.

[0044] Another aspect of the present invention provides an elevator light curtain. It should be noted that the elevator light curtain provided by the embodiment of the present invention and the method for identifying transparent, translucent, and small-volume objects provided by the embodiment of the present invention are based on the same inventive concept. Therefore, the specific implementation of this embodiment can refer to the implementation of the aforementioned method for identifying transparent, translucent, and small-volume objects, and the repeated parts will not be repeated.

[0045] An elevator light curtain comprises a processor and a memory, wherein the memory stores at least one instruction, and the instruction is executed by the processor, so that the elevator light curtain executes the method for the elevator light curtain to identify transparent, translucent, and small-volume objects described in the above embodiment.

[0046] In practical applications, the light-blocking structure 103 itself or the combination of the light-blocking structure 103 and the circuit board where the first receiving tube 102 is located forms a cavity that can accommodate the first receiving tube 102. The cavity is only provided with a narrow and long opening facing the filter strip. The vertical cross-section of the cavity is a trumpet-shaped shape that is large outside and small inside. The light-blocking structure 103 extends forward to the filter strip, which can prevent the first receiving tube 102 from directly receiving the infrared rays reflected from the inner surface of the filter strip. The narrow and long opening can expand the angle of light entering from the vertical direction and reduce the angle of light entering from the horizontal direction, which can avoid interference in the horizontal direction. For example, when the elevator is fully loaded, the clothes of people near the door are easy to reflect infrared rays. If the horizontal angle is large, it is easy to make a misjudgment.

[0047] In practical applications, the inner wall of the light-blocking structural member 103 is provided with a reflective coating, and the infrared signal can be reflected by the reflective coating to increase the sensitivity of the first receiving tube 102 .

[0048] In actual applications, the trumpet-shaped curved surface or inclined surface of the inner wall of the light-blocking structure 103 is provided with a reflective coating, and the left and right sides of the inner wall of the light-blocking structure 103 are not provided with a reflective coating, which can expand the detection sensitivity of infrared rays from the vertical direction and reduce the detection sensitivity of diffusely reflected infrared rays from the horizontal direction, thereby avoiding signal interference in the horizontal direction.

[0049] In summary, the elevator light curtain described in the present invention can realize the recognition of transparent, translucent and small-volume objects, with accurate judgment and low probability of misjudgment and missed judgment.

[0050] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the above implementation is only to illustrate the technical concept and features of the present invention, and its purpose is to enable people familiar with this technology to understand the content of the present invention and implement it, and it cannot be used to limit the protection scope of the present invention. All equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for identifying transparent, translucent, and small-volume objects, characterized in that: The elevator light curtain used includes a light curtain TX end (100) and a light curtain RX end (200). The light curtain TX end (100) is provided with a plurality of first transmitting tubes (101) and a plurality of first receiving tubes (102), each first receiving tube (102) cooperates with at least one first transmitting tube (101) to form a reflection signal group, and a light blocking structure (103) is provided at each of the plurality of first receiving tubes (102); The light curtain RX end (200) is provided with a plurality of second receiving tubes (201), and each second receiving tube (201) cooperates with at least one first transmitting tube (101) to form a corresponding signal group; During the process of closing the elevator door, the elevator light curtain starts scanning, and the reflection signal group and the corresponding shooting signal group work simultaneously, that is, when the first transmitting tube (101) emits infrared rays, the corresponding first receiving tube (102) and the second receiving tube (201) are simultaneously turned on for signal detection, and the following judgment is performed: Determine 1 whether the second receiving tube (201) cannot receive the infrared signal. If the result is yes, determine that there is an obstruction. If the result is no, proceed to determine 2. Determine 2: whether all first receiving tubes (102) have no signal. If the result is yes, determine that there is no obstruction. If the result is no, proceed to determine 3; Determine 3 whether only part of the first receiving tubes (102) receive the signal; if the result is yes and the signal strength is higher than the minimum signal strength that the first receiving tube (102) can accept, determine that there is an obstruction; if the result is yes but the signal strength is only the minimum signal strength that the first receiving tube (102) can accept, determine that there is no obstruction; if the result is no, proceed to determine 4; Judgment 4: Make judgments through one or more of the following three methods: Determine whether 4.1 satisfies: U a -b1<U i <U a+ b1, where U i is the voltage received by any first receiving tube (102) in this round of scanning, U a is the average value of the voltages of all first receiving tubes (102) in this round of scanning, and b1 is the set allowable error of the first voltage; Determine whether 4.2 satisfies: U i -b2<U i+1 <U i +b2, where U i is the voltage received by any first receiving tube (102) in this round of scanning, U i+1 Yes with U i the voltage received by the first receiving tube (102) adjacent to the corresponding first receiving tube (102), b2 being the set second voltage allowable error; Determine whether 4.3 satisfies: U c -b3<U a <U c +b3, where U a is the actual average value of the voltages of all first receiving tubes (102) in this round of scanning, and detects the distance between the light curtains during the scanning process, U c is the theoretical average value of the voltages of all first receiving tubes (102) at the light curtain distance, and b3 is the set allowable error of the third voltage; If the conditions are met, it is determined that there is no obstruction. If the conditions are not met, it is determined that there is a transparent obstruction.

2. A method for identifying transparent, semi-transparent, small-volume objects according to claim 1, characterized in that: The data b1, b2, b3, U c All are obtained from the laboratory: in the laboratory, an elevator environment is simulated, the light curtain TX end (100) and the light curtain RX end (200) are both installed on the elevator door, and no shielding is set between the light curtain TX end (100) and the light curtain RX end (200). Multiple rounds of scanning are performed, and the voltages of all first receiving tubes (102) in the multiple rounds of scanning are collected, that is, the reflected light signal data from the filter strip of the light curtain RX end (200) and the elevator door frame are collected, and b1, b2, b3, and U are obtained by analyzing the collected data. c , recorded in the MCU's memory.

3. A method for identifying transparent, semi-transparent, small-volume objects according to claim 2, characterized in that: When the first voltage allowable error b1 is obtained through analysis, the following method is used: The voltage data from the first first receiving tube (102) to the last first receiving tube (102) in each round are collected, the average value of the voltage data is calculated, and then the maximum difference between the voltage data of all first receiving tubes (102) in the round and the average voltage value of the round is calculated, and the maximum value of the maximum difference of multiple rounds is selected and multiplied by a set coefficient and recorded as b1.

4. A method for identifying transparent, semi-transparent, small-volume objects according to claim 2, characterized in that: When the second voltage allowance b2 is obtained through analysis, the following method is used: The voltage data from the first first receiving tube (102) to the last first receiving tube (102) in each round are collected, the voltage difference between two adjacent first receiving tubes (102) is calculated, the maximum value of the voltage difference in each round is calculated, and the maximum value of the voltage difference in multiple rounds is selected and multiplied by a set coefficient and recorded as b2.

5. The method for identifying transparent, semi-transparent, small-volume objects according to claim 2, characterized in that: The third voltage allowable error b3 and U c , use the following method: Detect the distance between elevator light curtains, U c is the average value of the voltage of all first receiving tubes (102) at this distance, and the distance between the elevator light curtains is adjusted to obtain U c The relationship between the distance to the light curtain; The voltage difference between the first receiving tube (102) and the last first receiving tube (102) in each round of scanning at the same distance is collected, and the maximum value of the voltage difference in multiple rounds of scanning is selected and multiplied by a set coefficient and recorded as b3.

6. A method for identifying transparent, semi-transparent, small-volume objects according to any one of claims 2 to 5, characterized in that: During the laboratory data collection, the light curtain is adjusted several times during multiple rounds of scanning. The adjustment methods include one or more of the following: Adjust the distance between the elevator light curtain TX end and the light curtain RX end (200); Adjusting the emission intensity of the first transmitting tube (101) at the elevator light curtain TX end; Adjust the horizontal tolerance between the elevator light curtain TX end and the light curtain RX end (200); Adjust the longitudinal tolerance between the elevator light curtain TX end and the light curtain RX end (200); Adjust the horizontal allowable angle between the elevator light curtain TX end and the light curtain RX end (200); Adjust the longitudinal allowable angle between the elevator light curtain TX end and the light curtain RX end (200); Adjust the cleanliness of the elevator light curtain filter strip and elevator door frame.

7. An elevator light curtain, characterized in that: The invention comprises a processor and a memory, wherein at least one instruction is stored in the memory, and the instruction is executed by the processor, so that the elevator light curtain executes the method for the elevator light curtain to identify transparent, translucent and small-volume objects according to any one of claims 1 to 6.

8. An elevator light curtain according to claim 7, characterized in that: The light-shielding structural component (103) itself or the combination of the light-shielding structural component (103) and the circuit board on which the first receiving tube (102) is located forms a cavity that accommodates the first receiving tube (102); the cavity is only provided with a narrow and long opening facing the filter strip; the vertical cross-section of the cavity is a trumpet-shaped shape that is larger on the outside and smaller on the inside; and the light-shielding structural component (103) extends forward to the filter strip.

9. An elevator light curtain according to claim 8, characterized in that: The inner wall of the light-blocking structural component (103) is provided with a reflective coating.

10. An elevator light curtain according to claim 9, characterized in that: The trumpet-shaped curved surface or inclined surface of the inner wall of the light-shielding structural component (103) is provided with a reflective coating, and the left and right side surfaces of the inner wall of the light-shielding structural component (103) are free of a reflective coating.

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