Photoelectric sensor for detecting transparent objects and method for detecting transparent objects

Abstract

The present invention relates to the technical field of photoelectric sensors, and in particular to a photoelectric sensor for detecting transparent objects and a method for detecting transparent objects, comprising: a receiving tube array, the receiving tube array is connected to a plurality of receiving tubes; irradiating light to form a light spot on the receiving tube array, the receiving tubes respectively generate light intensity signals according to the light spots; a sensor circuit, the sensor circuit is connected to the receiving tube array, the sensor circuit generates an output signal according to each light intensity signal; a processing device, connected to the sensor circuit, and obtains the irradiation information of the light spot according to the output signal to determine whether the transparent object exists. The beneficial effect of the present invention is that by setting a plurality of receiving tubes to form a receiving tube array, the light spot formed on the receiving tube array after the transparent object is refracted is detected, and then the signal intensity caused by the refracted light and the distribution of the refracted light on the receiving tube array are effectively determined to determine whether the transparent object exists, thereby improving the reliability of the sensor.

Description

Technical Field

[0001] The present invention relates to the technical field of photoelectric sensors, and in particular to a photoelectric sensor for detecting transparent objects and a method for detecting transparent objects. Background Art

[0002] A photoelectric sensor is a device that converts light signals into electrical signals based on the photoelectric effect. Based on its physical properties, photoelectric sensors are widely used in various measuring instruments for automation equipment, the Internet of Things, and smart homes. For example, in the industrial field, because the products on a specific production line need to meet higher dust-free and sterile requirements, or the products are easily damaged by contact, a non-contact sensor is often required to meet the needs of industrial production. In this type of application scenario, photoelectric sensors can better meet the needs of non-contact measurement due to their physical properties. At the same time, in this type of application scenario, transparent objects, such as transparent test tubes, glass bottles, transparent films, etc., have certain measurement difficulties due to their physical properties.

[0003] In the prior art, there are technical solutions that use photoelectric sensors to detect transparent objects. For example, a photoelectric sensor is set to obtain the change in the amplitude of the signal reflected by the transparent object to determine whether there is a transparent object between the sensor and the reflector. However, in the actual implementation process, the inventor found that since the attenuation of the reflected light by the transparent object is small, the technical solutions based on the amplitude of the reflected signal in the prior art often have problems such as low signal-to-noise ratio, poor reliability, and difficulty in adjustment, which leads to poor reliability of the sensor. Summary of the invention

[0004] In view of the above problems existing in the prior art, a photoelectric sensor for detecting a transparent object and a method for detecting a transparent object are now provided.

[0005] The specific technical solutions are as follows:

[0006] A photoelectric sensor for detecting a transparent object, comprising:

[0007] A receiving tube array, wherein the receiving tube array is connected to a plurality of receiving tubes;

[0008] An irradiation light forms a light spot on the receiving tube array, and the receiving tubes respectively generate a light intensity signal according to the light spot;

[0009] A sensor circuit, the sensor circuit is connected to the receiving tube array, and the sensor circuit generates an output signal according to each of the light intensity signals;

[0010] A processing device, the processing device is connected to the sensor circuit, and the processing device obtains the irradiation information of the light spot according to the output signal;

[0011] The processing device determines whether the transparent object exists according to the illumination information.

[0012] Preferably, the photoelectric sensor further comprises a transmitting tube, and the transmitting tube is used to form the irradiation light;

[0013] The transmitting tube and the receiving tube array are arranged on the same side, and the irradiation light passes through a reflecting surface from the transmitting tube to the receiving tube array;

[0014] Alternatively, the transmitting tube and the receiving tube array are arranged opposite to each other.

[0015] Preferably, an emitting lens is arranged in front of the emitting tube, and the emitting lens processes the irradiation light so that the irradiation light forms an irradiation light spot with a specific arrangement;

[0016] A receiving lens is arranged in front of the receiving tube array, and the receiving lens is used to focus the irradiation light.

[0017] Preferably, the sensor circuit comprises:

[0018] A signal processing circuit, the signal processing circuit is connected to the receiving tube array, and the signal processing circuit generates the output signal according to the light intensity signal;

[0019] A timing circuit, the timing circuit is connected to the receiving tube array, and the timing circuit sends a timing signal to the receiving tube array;

[0020] The receiving tube array controls the light intensity signal generated by each receiving tube according to the timing signal to be input into the signal processing circuit in sequence.

[0021] Preferably, in the receiving tube array, the receiving tubes are arranged in a horizontal arrangement, a vertical arrangement, a rectangular arrangement, a polygonal arrangement, or a cross arrangement.

[0022] A method for detecting a transparent object, applicable to the above-mentioned photoelectric sensor, comprising:

[0023] Step S1: using a transmitting tube to project irradiation light to the receiving tube array to generate a light spot on the receiving tube array, and then respectively acquiring the output signal corresponding to each receiving tube;

[0024] Step S2: judging whether the transparent object exists on the propagation path of the irradiation light according to the output signal and pre-generated comparison data;

[0025] If yes, generate a detection signal and then return to step S1;

[0026] If not, return to step S1.

[0027] Preferably, before step S1, a comparative data collection process is also included, which specifically includes:

[0028] Step S01: using the transmitting tube to project the irradiation light to the receiving tube array to generate the light spot on the receiving tube array, and then respectively acquiring a plurality of the output signals;

[0029] Step S02: acquiring the illumination value corresponding to each receiving tube according to the output signal;

[0030] Step S03: Generate illumination ranking and average illumination according to the illumination value, and use the illumination ranking and average illumination as the comparison data.

[0031] Preferably, the step S2 comprises:

[0032] Step S21: acquiring a current illumination value corresponding to each of the receiving tubes according to the output signal;

[0033] Step S22: judging whether the transparent object exists on the propagation path of the illumination light according to the current illumination value and the comparison data;

[0034] If yes, generate the detection signal, and then return to step S1;

[0035] If not, return to step S1.

[0036] Preferably, the step S22 includes:

[0037] Step A221: generating a current illumination ranking according to the current illumination value;

[0038] Step A222: judging whether the order of the illumination values ​​of the receiving tubes has changed according to the current illumination value order and the illumination order;

[0039] If yes, it is considered that the transparent object exists on the propagation path of the irradiation light, the detection signal is generated, and then the process returns to step S1;

[0040] If not, it is considered that the transparent object does not exist and the process returns to step S1.

[0041] Preferably, the step S22 includes:

[0042] Step B221: generating a current average illumination value according to the current illumination value;

[0043] Step B222: judging whether the illumination value of the receiving tube changes according to the current average illumination and the average illumination;

[0044] If yes, it is considered that the transparent object exists on the propagation path of the irradiation light, the detection signal is generated, and then the process returns to step S1;

[0045] If not, it is considered that the transparent object does not exist and the process returns to step S1.

[0046] The above technical solution has the following advantages or beneficial effects: by setting up multiple receiving tubes to form a receiving tube array, the detection of the light spot formed on the receiving tube array after the transparent object is refracted is realized, and then the presence of the transparent object can be effectively judged based on the signal strength caused by the refracted light and the distribution of the refracted light on the receiving tube array, thereby improving the reliability of the sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The embodiments of the present invention will be described more fully with reference to the attached drawings, which are provided for illustration and description only and are not intended to limit the scope of the present invention.

[0048] Figure 1 It is an overall schematic diagram of an embodiment of the present invention;

[0049] Figure 2 A schematic diagram of the connection between the sensor circuit and the processing device in another embodiment of the present invention;

[0050] Figure 3 The configuration of the transmitting tube and receiving tube array in the embodiment of the present invention;

[0051] Figure 4 The configuration of the transmitting tube and receiving tube array in another embodiment of the present invention;

[0052] Figure 5 A schematic diagram of an optical path in an embodiment of the present invention;

[0053] Figure 6 Schematic diagram of the output signal amplitude of the receiving tube array in an embodiment of the present invention;

[0054] Figure 7 A schematic diagram of a lens in an embodiment of the present invention;

[0055] Figure 8 A schematic diagram of a sensor circuit in an embodiment of the present invention;

[0056] Fig. 9A Schematic diagram of a receiving tube array in an embodiment of the present invention;

[0057] Fig. 9B A schematic diagram of a receiving tube array in another embodiment of the present invention;

[0058] Fig. 9C A schematic diagram of a receiving tube array in another embodiment of the present invention;

[0059] Fig.9D A schematic diagram of a receiving tube array in another embodiment of the present invention;

[0060] Fig.9E A schematic diagram of a receiving tube array in another embodiment of the present invention;

[0061] Fig.10 Schematic diagram of a photoelectric sensor in an embodiment of the present invention;

[0062] Fig.11 Schematic diagram of the detection method in an embodiment of the present invention;

[0063] Fig.12 A schematic diagram of a comparative data collection process in an embodiment of the present invention;

[0064] Fig.13 This is a schematic diagram of sub-steps of step S2 in an embodiment of the present invention;

[0065] Fig.14 This is a schematic diagram of sub-steps of step S22 in an embodiment of the present invention;

[0066] Fig.15 Schematic diagram of sub-steps of step S22 in an embodiment of the present invention. DETAILED DESCRIPTION

[0067] 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.

[0068] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0069] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, but they are not intended to limit the present invention.

[0070] The present invention comprises:

[0071] A photoelectric sensor for detecting transparent objects, such as Figure 1 As shown, including:

[0072] A receiving tube array 1, wherein the receiving tube array 1 is connected to a plurality of receiving tubes 11;

[0073] An irradiated light forms a light spot on the receiving tube array 1, and the receiving tubes 1 generate a light intensity signal according to the light spot;

[0074] The sensor circuit 2 is connected to the receiving tube array 1, and the sensor circuit 2 generates an output signal according to each light intensity signal;

[0075] A processing device 4, the processing device 4 is connected to the sensor circuit 2, and the processing device 4 obtains the illumination information of the light spot according to the output signal;

[0076] The processing device 4 determines whether the transparent object exists based on the illumination information.

[0077] Specifically, in view of the problem that the reliability of the photoelectric sensor in the prior art for transparent object detection is low due to the attenuation of the amplitude of the received signal of the receiving tube, in this embodiment, a plurality of receiving tubes 11 are combined into a receiving tube array, and the light intensity of the irradiation light received by each receiving tube 11 is obtained one by one, thereby obtaining the projected light spot of the irradiation light on the receiving tube array 1. By judging the irradiation information such as the area, irradiation intensity, and position change of the projected light spot, it can be effectively judged whether the irradiation light is refracted by a transparent object with a different density from the air, thereby achieving effective detection of transparent objects and improving the accuracy and reliability of detection.

[0078] During the implementation process, the receiving tube 11 is a receiving tube implemented based on the prior art, which generates a light intensity signal according to the light intensity of the irradiated light based on the photoelectric effect. A plurality of receiving tubes 11 form a receiving tube array 1, which is arranged in a photoelectric sensor. In one embodiment, the receiving tube array 1 also includes a switch matrix, in which a plurality of controllable switches are arranged, each controllable switch is respectively connected to a receiving tube 11, which selects the light intensity signal input to the sensor circuit 2 under the control of the control signal. The control signal can be a control signal generated by a photoelectric sensor through a specific computer program, or it can be a timing signal. For example, in one embodiment, the switch matrix turns on and off the controllable switches in sequence under the control of the timing signal, so that the light intensity signals generated by the plurality of receiving tubes 11 are sequentially input to the sensor circuit 2. The sensor circuit 2 mainly includes a signal processing circuit, which is used to amplify, phase-lock, demodulate and perform calculation processing on the received light intensity, and then generate an output signal for characterizing the light intensity. The sensor circuit 2 is connected to the processing device 4 through a corresponding communication port. The processing device 4 can be understood as one or more application-specific integrated circuits (ASICs), DSPs, programmable logic devices (PLDs), complex programmable logic devices (CPLDs), field programmable gate arrays (FPGAs), general-purpose processors, controllers, microcontrollers (MCUs), microprocessors, or other electronic components, thereby realizing the reading of output signals and realizing the detection of transparent objects according to corresponding computer programs. In one embodiment, the processing device 4 also has a switch output port, and the processing device 4 is connected to an external switch tube through the switch output port, thereby realizing the control of the switch tube according to the detection result. In order to achieve better control of external devices, the processing device 4 can calculate the obtained output signal based on the existing technology, for example, the duration and number of transparent objects detected are counted, so as to generate corresponding output signals according to the actual needs of users. In one embodiment, the processing device 4 can also be set as a control device of the sensor circuit 2, which sends corresponding control parameters to the sensor circuit 2 through the corresponding communication protocol, such as the current-voltage conversion multiple, the transmitting power of the transmitting tube, etc. In this embodiment, the processing device 4 sends control parameters to the sensor circuit 2 and receives the output signal sent by the sensor circuit 2 through the same communication port. In another embodiment, if Figure 2 As shown, the processing device 4 is provided with a bus communication port and an ALU port. The bus communication port is used to send control parameters to the sensor circuit 2, and the ALU port is used to receive the ALU output of the sensor circuit 2. The above two communication modes can be set according to actual needs, which does not constitute a limitation on the actual technical solution.

[0079] In a preferred embodiment, the photoelectric sensor further includes one or more emitting tubes 3, which are used to form irradiation light; the irradiation light can be a point-shaped, a straight line, a cross, or other shaped light source.

[0080] like Figure 3 and Figure 4 As shown, the transmitting tube 3 and the receiving tube array 1 are arranged on the same side, and the irradiated light passes through a reflecting surface B from the transmitting tube 3 to the receiving tube array 1;

[0081] Alternatively, the transmitting tube 3 and the receiving tube array 1 are arranged opposite to each other.

[0082] Specifically, in view of the problem that the photoelectric sensors in the prior art cannot adapt well to the actual monitoring needs, in this embodiment, a better monitoring effect is achieved by setting the transmitting tube 3 on the same side or opposite to the receiving tube array 1. For example, in one embodiment, for a larger monitoring area, by setting the transmitting tube 3 and the receiving tube array 1 opposite to each other, a better monitoring effect of the transparent object A passing through a larger activity space is achieved. In another embodiment, for a transparent object A with a lower refractive index or a thinner thickness, by setting the transmitting tube 3 and the receiving tube array 1 on the same side, the irradiation light generated by the transmitting tube 3 is refracted twice by the transparent object A during the reflection process, so that the light spot generated on the receiving tube array 1 moves within a larger range, thereby improving the monitoring sensitivity.

[0083] In the implementation process, take the embodiment in which the transmitting tube 3 and the receiving tube array 1 are arranged on the same side as an example. Figure 3 As shown, when there is no transparent object A between the transmitting tube 3 and the receiving tube array 1, the irradiation light generated by the transmitting tube 3 is reflected by the reflecting surface B and projects a light spot C on the receiving tube array 1. At this time, the processing device 4 can obtain the position of the light spot C on the receiving tube array 1 at the current moment by reading the output signal of each receiving tube 11 and performing calculations. Then, as Figure 5 As shown, when a transparent object A is between the transmitting tube 3 and the receiving tube array 1, the irradiated light is refracted by the transparent object A, causing the position of the light spot C on the receiving tube array 1 to shift, thereby causing the signals output by different receiving tubes 1 to change. For example, in one embodiment, Figure 6 As shown, when there is no transparent object A, a curve D1 can be obtained by fitting the signal amplitude output by each receiving tube 11. According to the curve D1, it can be seen that the center of the light spot C is near the fourth receiving tube. When there is a transparent object A, a curve D2 can be obtained by fitting the signal amplitude output by each receiving tube 11. According to the curve D2, the center of the light spot C moves to the seventh receiving tube. Therefore, by judging the movement of the light spot C, it can be effectively sensed whether there is a transparent object A.

[0084] In a preferred embodiment, Figure 7 As shown, a transmitting lens 31 is arranged in front of the transmitting tube 3, and the transmitting lens 31 processes the irradiation light so that the irradiation light forms an irradiation spot with a specific arrangement; a receiving lens 12 is arranged in front of the receiving tube array 1, and the receiving lens 12 is used to focus the irradiation light.

[0085] Specifically, in order to address the problem that the photoelectric sensor in the prior art is difficult to effectively detect the transparent object A only by receiving the signal strength, in this embodiment, an emitting lens 31 and a receiving lens 12 are provided to focus the irradiated light during the propagation process, thereby changing the size of the light spot C formed by the irradiated light on the receiving tube array 1, further reflecting the influence of the transparent object A on the propagation light path, thereby achieving effective monitoring of the transparent object A.

[0086] During the implementation, the emitting lens 31 processes the irradiation light generated by the emitting tube 3, so that the irradiation light emitted from the emitting tube 3 to the surrounding is converted into parallel light through the emitting lens 31, thereby forming the required irradiation light spot. The irradiation light spot can form a point light spot, a straight line light spot, a cross light spot, etc. according to the arrangement of different emitting tubes 3, so as to meet the needs of monitoring different types of transparent objects.

[0087] In a preferred embodiment, Figure 8 As shown, the sensor circuit 2 includes:

[0088] A signal processing circuit 21, the signal processing circuit 21 is connected to the receiving tube array, and the signal processing circuit 21 generates an output signal according to the light intensity signal;

[0089] A timing circuit 22, the timing circuit 22 is connected to the receiving tube array 1, and the timing circuit 22 sends a timing signal to the receiving tube array 1;

[0090] The receiving tube array 1 controls the light intensity signal generated by each receiving tube 11 according to the timing signal to be input into the signal processing circuit in sequence.

[0091] Specifically, in order to effectively receive the light intensity signals generated by multiple receiving tubes 11, in this embodiment, a timing circuit 22 is set to send a timing signal to the receiving tube array, and the receiving tube array 1 sequentially inputs the light intensity signals of the receiving tubes 1 into the signal processing circuit according to the timing signal. At the same time, the timing circuit 22 also sends the same timing signal to the signal processing circuit 21, so that the timing circuit completes phase locking and demodulation according to the signal processing circuit, thereby realizing the processing of the light intensity signal output by each receiving tube 11, and then the processing device 4 can read the light intensity of each receiving tube 11 according to the processing signal.

[0092] In a preferred embodiment, the signal processing circuit 21 further includes:

[0093] A switched capacitor amplifier 211, the input end of the switched capacitor amplifier 211 is connected to the output end of the receiving tube array 1;

[0094] A sampling and integrating unit 212, wherein an input end of the sampling and integrating unit 212 is connected to an output end of the switched capacitor amplifier 211;

[0095] The signal processing unit 213 has an input end connected to the output end of the sampling integration unit 212 .

[0096] Specifically, in order to achieve a better processing effect on the light intensity signals output by multiple receiving tubes 11, in this embodiment, by sequentially setting the switched capacitor amplifier 211, the sampling integration unit 212, and the signal processing unit 213, a phase-locking and demodulation process is implemented according to the timing signal, thereby accurately processing the light intensity signal output by each receiving tube 11.

[0097] In the implementation process, the switched capacitor amplifier 211 refers to a phase-locked amplifier implemented based on switched capacitor technology, which completes the phase-locked process based on the timing signal generated by the timing circuit 22, thereby achieving lower power consumption and better noise suppression effect. In one embodiment, the sampling integration unit 212 and the signal processing unit 213 are connected to a register unit 6, and the current-voltage conversion gain, sampling times and integration time are adjusted by the control parameters recorded in the register unit 6. The register unit 6 can be connected to an external control device through a bus protocol in the prior art to receive control parameters. According to actual needs, the register can rely on a check bit or a check algorithm to verify the received control parameters to achieve better anti-interference. The signal processing unit 21 is an arithmetic logic circuit, which performs addition, subtraction, multiplication, division and other operations on the received signal under the adjustment of the control parameters, thereby generating an output signal for characterizing the light intensity.

[0098] In a preferred embodiment, the sensor circuit 2 also includes a transmitting tube driving circuit 5, which is connected to the timing circuit 22 and one or more transmitting tubes 3. The transmitting tube driving circuit 5 drives the transmitting tube 3 to generate irradiation light under the control of the timing signal, thereby achieving phase locking between the signal processing circuit 21 and the transmitting tube driving circuit 5 through the same timing signal.

[0099] In a preferred embodiment, Fig. 9A , Fig. 9B , Fig. 9C , Fig.9D , Fig.9E As shown, in the receiving tube array 1 , the receiving tubes 11 are arranged in a horizontal arrangement, a vertical arrangement, a rectangular arrangement, a polygonal arrangement, or a cross arrangement.

[0100] Specifically, in view of the problem that the photoelectric sensor in the prior art cannot adapt well to the sensing requirements of different transparent objects, in this embodiment, the arrangement of the receiving tubes 11 in the receiving tube array 1 is adjusted, and the receiving tube arrays 1 with different arrangements respectively detect the movement of the light spot in the X-axis direction or the Y-axis direction in different scenes, thereby achieving a better sensing effect. For example, in one embodiment, a transparent object of a certain shape may cause a large displacement of the light spot in the X-axis direction, while the displacement in the Y-axis direction is not obvious. At this time, a better detection effect for such objects may be achieved by setting a horizontally arranged receiving tube array 1.

[0101] As an optional implementation, the sensor circuit 2 can be implemented by a programmable sensor circuit. For example, CN202210103335.0 discloses a programmable photoelectric sensor, the circuit part of which can be used for the sensor circuit 2. This type of programmable sensor circuit usually includes a register unit 6, which is connected to an external host computer through a communication protocol in the prior art, such as I2C, SPI or a single-wire communication interface, to receive control parameters output by the external host computer, and then adjust the parameters of the switch capacitor amplifier 211, the sampling integration unit 212, the signal processing unit 213, the timing circuit 22 and the transmitting tube drive circuit 5, so that the sensor is more in line with actual needs. Depending on the actual setting environment, it is also possible to add a verification algorithm during the communication process, set a check bit in the register unit 6, and set a separate alarm circuit to avoid register flip failures caused by external electromagnetic interference. The host computer and the processing device can be the same device, which sends control parameters and receives signals output by the sensor circuit 2 through independent ports, or sends control parameters and receives output signals through the same port. For example, in one embodiment, Fig.10 As described above, the photoelectric sensor integrates a receiving tube array 1, a sensor circuit 2, a transmitting tube driving circuit 5 and a register unit 6, which is connected to an external transmitting tube 3 and a processing device 4, and controls the transmitting tube 3 to generate irradiation light, so that a light spot is formed on the receiving tube array 1 in the photoelectric sensor, and then the sensor circuit 2 generates an output signal according to the light intensity signal generated by each receiving tube 11, so that the processing device 4 can obtain the movement of the light spot on the receiving tube array 1 according to the output signal, thereby judging whether there is a transparent object on the propagation path of the irradiation light.

[0102] As an optional embodiment, the above-mentioned cross-shaped receiving tube array can be implemented by a receiving tube array 1 with a specific central receiving tube. For example, CN202210139242.3 discloses a photoelectric sensor, in which the receiving tube array can be used for the above-mentioned receiving tube array 1. The receiving tube array has a first type of receiving tube arranged in the horizontal direction and the vertical direction, and a second type of receiving tube arranged in the center position. Among them, the second type of receiving tube is composed of four sub-receiving tubes, each of which has an area of ​​half of the first type of receiving tube, and adjacent sub-receiving tubes are connected in parallel in the horizontal direction or the vertical direction under the control of the control signal to form two first type receiving tubes in the horizontal direction or two second type receiving tubes in the vertical direction. Since this type of receiving tube array 1 can completely collect the continuous output signals of multiple receiving tubes 11 of the same area in the horizontal direction and the vertical direction, the movement of the light spot on the receiving tube array 1 is reflected by the light intensity change trend of each receiving tube. At the same time, by setting two timing signals with a phase difference between them to simultaneously control the receiving tubes 1 in the horizontal and vertical directions, it is possible to further collect the light intensity in the horizontal and vertical directions, thereby achieving a higher detection frequency.

[0103] A method for detecting a transparent object is suitable for the above-mentioned photoelectric sensor, such as Fig.11 As shown, including:

[0104] Step S1: using a transmitting tube 3 to project irradiation light to the receiving tube array 1 to generate a light spot on the receiving tube array 1, and then obtaining the output signal corresponding to each receiving tube 11 respectively;

[0105] Step S2: judging whether there is a transparent object on the propagation path of the irradiation light according to the output signal and pre-generated comparison data;

[0106] If yes, generate a detection signal and then return to step S1;

[0107] If not, return to step S1.

[0108] Specifically, in order to address the problem that the photoelectric sensors in the prior art cannot effectively detect transparent objects based only on the signal attenuation amplitude, in this embodiment, a sensor array 1 is set to obtain the output signal of each receiving tube 11 respectively, and then the relevant information of the light spot on the current receiving tube array 1 is obtained according to the output signal, including the illumination intensity, the center position, the range, etc., and whether there is a transparent object is judged according to the pre-generated comparison data, thereby avoiding the problem of poor detection effect caused by the low attenuation amplitude of the light signal in the transparent object.

[0109] In the implementation process, step S1 includes: controlling the receiving tube array 1 through a timing signal, and then receiving the output signal of each receiving tube 11 in sequence according to a specific order. Step S2 also includes: calculating according to the output signal to obtain at least one parameter of the illumination intensity, the center position, and the light spot coverage range, and then comparing the parameter with the comparison data to determine whether there is a transparent object.

[0110] In a preferred embodiment, a comparison data collection process is also included before step S1, such as Fig.12 As shown, specifically including:

[0111] Step S01: using the transmitting tube 3 to project irradiation light to the receiving tube array 1 to generate a light spot on the receiving tube array 1, and then obtaining a plurality of output signals respectively;

[0112] Step S02: obtaining the illumination value corresponding to each receiving tube 11 according to the output signal;

[0113] Step S03: Generate illumination ranking and average illumination according to the illumination value, and use the illumination ranking and average illumination as comparison data.

[0114] Specifically, in order to address the problem in the prior art that transparent objects cannot be detected well by relying on the attenuation amplitude of the received signal, in this embodiment, the output signal of each receiving tube 11 is collected in sequence, and the illumination value corresponding to each receiving tube 11 is obtained based on the output signal, thereby generating an illumination ranking and average illumination corresponding to the entire receiving tube array 1, which facilitates comparison of the position and intensity change of the light spot after the transparent object refracts the irradiated light.

[0115] During the implementation process, Figure 6 As shown, in this embodiment, there are 8 receiving tubes. According to the illumination value of each receiving tube 11, an illumination ranking can be generated: {fourth receiving tube, fifth receiving tube, third receiving tube, sixth receiving tube, second receiving tube, first receiving tube, seventh receiving tube, eighth receiving tube}, and the average illumination calculated according to the illumination value. In the absence of a transparent object for refraction, the central illumination of the light spot is greater than the edge illumination, so the approximate position of the center point of the light spot can be reflected by the illumination ranking. When the illumination ranking changes, it means that the center point of the light spot has changed, which further indicates that there is a transparent object that refracts the irradiated light. At the same time, according to Figure 5 It can be seen that when the irradiated light passes through a transparent object, there will be attenuation, which will reduce the average illumination. Therefore, by using the average illumination as comparison data, it is possible to simultaneously determine whether there is a transparent object.

[0116] In a preferred embodiment, Fig.13 As shown, step S2 includes:

[0117] Step S21: obtaining the current illumination value corresponding to each receiving tube 11 according to the output signal;

[0118] Step S22: judging whether there is a transparent object on the propagation path of the irradiation light according to the current illumination value and the comparison data;

[0119] If yes, generate a detection signal and then return to step S1;

[0120] If not, return to step S1.

[0121] Specifically, in order to address the problem in the prior art that transparent objects cannot be detected well by relying on the attenuation amplitude of the received signal, in this embodiment, the current value corresponding to each receiving tube 11 is obtained, and then the illumination ranking and average illumination corresponding to the entire receiving tube array are generated, which facilitates comparison of the position and intensity change of the light spot after the transparent object refracts the irradiated light.

[0122] In a preferred embodiment, Fig.14 As shown, step S22 includes:

[0123] Step A221: generating a current illumination ranking according to the current illumination value;

[0124] Step A222: judging whether the order of the illumination values ​​of the receiving tubes has changed according to the current illumination value order and the illumination order;

[0125] If yes, it is considered that there is a transparent object on the propagation path of the irradiated light, a detection signal is generated, and then the process returns to step S1;

[0126] If not, it is considered that there is no transparent object and the process returns to step S1.

[0127] Specifically, in order to address the problem in the prior art that transparent objects cannot be detected well by relying on the attenuation amplitude of the received signal, in this embodiment, the current illumination value is obtained to generate the current illumination ranking, which reflects the position of the light spot on the receiving tube array 1, thereby realizing the detection of transparent objects, while avoiding the problem that transparent objects cannot be detected well by detecting the signal strength alone.

[0128] During the implementation process, Figure 5 As shown in the figure, when there is a transparent object, the current illumination order is changed to {seventh receiving tube, sixth receiving tube, fifth receiving tube, eighth receiving tube, fourth receiving tube, third receiving tube, second receiving tube, first receiving tube}. By comparing the current illumination order with the illumination order in the comparison data, it is possible to effectively determine whether the position of the light spot has changed, and then determine whether there is a transparent object that refracts the irradiated light.

[0129] In a preferred embodiment, Fig.15As shown, step S22 includes:

[0130] Step B221: Generate the current average illumination according to the current illumination value;

[0131] Step B222: judging whether the illumination value of the receiving tube changes according to the current average illumination and the average illumination;

[0132] If yes, it is considered that there is a transparent object on the propagation path of the irradiated light, a detection signal is generated, and then the process returns to step S1;

[0133] If not, it is considered that there is no transparent object and the process returns to step S1.

[0134] Specifically, in order to address the problem that the prior art cannot effectively detect transparent objects by detecting the attenuation of light signals based on a single photoelectric sensor, in this embodiment, by setting up multiple receiving tubes to generate the current average illumination, a better detection effect of the attenuation of the light signal is achieved, thereby improving the detection sensitivity.

[0135] During implementation, the above detection methods can be used selectively or simultaneously. For example, in one embodiment, only the change in illumination order is detected to obtain the change in the position of the light spot after refraction by the transparent object, so as to determine whether there is a transparent object. Alternatively, in another embodiment, the photoelectric sensor operates in a high reliability mode, and the processing device 4 comprehensively determines whether there is a transparent object by simultaneously determining the change in illumination order and the attenuation of the average illumination, thereby reducing the false alarm rate. For another example, in another embodiment, only the change in the current average illumination is detected, that is, the light attenuation caused by the transparent object is detected to determine whether there is a transparent object.

[0136] The beneficial effect of the present invention is that by setting the receiving tube array 1, the position, brightness, size and other parameters of the light spot formed by the transmitting tube 3 are detected, and then it is effectively judged whether the irradiated light is refracted by the transparent object during the propagation process, thereby avoiding the problem in the prior art that the transparent object is difficult to detect due to the small light attenuation caused by the transparent object. By adjusting the specific setting mode of the transmitting tube 3 and the receiving tube array 1, the detection range and optical path setting of the sensor can be changed according to different measurement scenes and user needs, thereby achieving a better detection effect for various transparent objects. By setting the programmable switching capacitor amplifier 211, the sampling integration unit 212, the signal processing unit 213, the timing circuit 22 and the transmitting tube driving circuit 5, the effective adjustment of the current-voltage conversion multiple, the transmitting power of the transmitting tube and other parameters is achieved, ensuring that the sensor does not enter the state of saturation or the output signal is small, so that the sensitivity, detection distance, detection range and other parameters of the sensor can be changed according to the needs of the user in actual use, thereby making the sensor more in line with the needs of the user.

[0137] The above are only preferred embodiments of the present invention, and are not intended to limit the implementation methods and protection scope of the present invention. Those skilled in the art should be aware that all solutions obtained by equivalent substitutions and obvious changes made using the description and illustrations of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for detecting a transparent object, characterized in that: Suitable for photoelectric sensors; The photoelectric sensor comprises a receiving tube array, wherein the receiving tube array is connected with a plurality of receiving tubes; An irradiation light forms a light spot on the receiving tube array, and the receiving tubes respectively generate a light intensity signal according to the light spot; A sensor circuit, the sensor circuit is connected to the receiving tube array, and the sensor circuit generates an output signal according to each of the light intensity signals; A processing device, the processing device is connected to the sensor circuit, and the processing device obtains the illumination information of the light spot and detects the transparent object according to the output signal; The detection method comprises: Step S1: using a transmitting tube to project irradiation light to the receiving tube array to generate a light spot on the receiving tube array, and then respectively acquiring the output signal corresponding to each receiving tube; Step S2: judging whether the transparent object exists on the propagation path of the irradiation light according to the output signal and pre-generated comparison data; If yes, generate a detection signal and then return to step S1; If not, return to step S1; Before step S1, a comparative data collection process is also included, which specifically includes: Step S01: using the transmitting tube to project the irradiation light to the receiving tube array to generate the light spot on the receiving tube array, and then respectively acquiring a plurality of the output signals; Step S02: acquiring the illumination value corresponding to each receiving tube according to the output signal; Step S03: Generate illumination ranking and average illumination according to the illumination value, and use the illumination ranking and average illumination as the comparison data.

2. The detection method according to claim 1, characterized in that: The step S2 comprises: Step S21: acquiring a current illumination value corresponding to each of the receiving tubes according to the output signal; Step S22: judging whether the transparent object exists on the propagation path of the illumination light according to the current illumination value and the comparison data; If yes, generate the detection signal, and then return to step S1; If not, return to step S1.

3. The detection method according to claim 2, characterized in that: The step S22 comprises: Step A221: generating a current illumination ranking according to the current illumination value; Step A222: judging whether the order of the illumination values ​​of the receiving tubes has changed according to the current illumination value order and the illumination order; If yes, it is considered that the transparent object exists on the propagation path of the irradiation light, the detection signal is generated, and then the process returns to step S1; If not, it is considered that the transparent object does not exist and the process returns to step S1.

4. The detection method according to claim 2, characterized in that: The step S22 comprises: Step B221: generating a current average illumination value according to the current illumination value; Step B222: judging whether the illumination value of the receiving tube changes according to the current average illumination and the average illumination; If yes, it is considered that the transparent object exists on the propagation path of the irradiation light, the detection signal is generated, and then the process returns to step S1; If not, it is considered that the transparent object does not exist and the process returns to step S1.

5. The detection method according to claim 1, characterized in that: The photoelectric sensor further comprises a transmitting tube, and the transmitting tube is used to form the irradiation light; The transmitting tube and the receiving tube array are arranged on the same side, and the irradiation light passes through a reflecting surface from the transmitting tube to the receiving tube array; Alternatively, the transmitting tube and the receiving tube array are arranged opposite to each other.

6. The detection method according to claim 5, characterized in that: An emitting lens is arranged in front of the emitting tube, and the emitting lens processes the irradiation light so that the irradiation light forms an irradiation light spot with a specific arrangement; The specifically arranged illumination light spots include point-shaped light spots, straight-line-shaped light spots and cross-shaped light spots; a receiving lens is arranged in front of the receiving tube array, and the receiving lens is used to focus the illumination light.

7. The detection method according to claim 1, characterized in that: The sensor circuit comprises: A signal processing circuit, the signal processing circuit is connected to the receiving tube array, and the signal processing circuit generates the output signal according to the light intensity signal; A timing circuit, the timing circuit is connected to the receiving tube array, and the timing circuit sends a timing signal to the receiving tube array; The receiving tube array controls the light intensity signal generated by each receiving tube according to the timing signal to be input into the signal processing circuit in sequence.

8. The detection method according to claim 1, characterized in that: In the receiving tube array, the receiving tubes are arranged in a horizontal arrangement, a vertical arrangement, a rectangular arrangement, a polygonal arrangement, or a cross arrangement.

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