CN114609687A - Photoelectric sensor for detecting transparent object and method for detecting transparent object - Google Patents

Abstract

The invention relates to the technical field of photoelectric sensors, in particular to a photoelectric sensor for detecting a transparent object and a method for detecting the transparent object, which comprises the following steps: the receiving tube array is connected with the plurality of receiving tubes; irradiating light to form light spots on the receiving tube array, and generating light intensity signals by the receiving tubes according to the light spots respectively; the sensor circuit is connected with the receiving tube array and respectively generates output signals according to each light intensity signal; and the processing device is connected with the sensor circuit and is used for acquiring the irradiation information of the light spots according to the output signals so as to judge whether the transparent object exists or not. The invention has the beneficial effects that: through setting up a plurality of receiver tubes in order to constitute the receiver tube array, realized the detection to the facula that transparent object refraction back formed on the receiver tube array, and then effectively judge whether there is transparent object according to signal intensity, the distribution of refraction light on the receiver tube array that the refraction light leads to, improved the reliability of sensor.

Description

Photoelectric sensor for detecting transparent object and method for detecting transparent object

Technical Field

The invention relates to the technical field of photoelectric sensors, in particular to a photoelectric sensor for detecting a transparent object and a method for detecting the transparent object.

Background

A photoelectric sensor is a device for converting optical signals into electric signals based on photoelectric effect. Based on the physical characteristics of the photoelectric sensor, the photoelectric sensor is widely applied to various measuring instruments of automation equipment, the Internet of things and smart homes. For example, in the industrial field, since products on a specific production line need to meet high dust-free and aseptic requirements, or products are easily damaged due to contact, and the like, a non-contact sensor is often needed to meet the requirements of industrial production. In the application scenes, the photoelectric sensor can better meet the non-contact measurement requirement due to the physical characteristics. Meanwhile, in the application scenes, transparent objects such as transparent test tubes, glass bottles, transparent films and the like have certain measurement difficulty due to the physical characteristics of the transparent objects.

In the prior art, there is a technical scheme of detecting a transparent object by using a photoelectric sensor. For example, a photoelectric sensor is arranged to acquire the amplitude variation of a signal reflected by a transparent object, so as to determine whether the transparent object exists between the sensor and the reflector. However, in the practical implementation process, the inventor finds that, because the attenuation of the reflected light by the transparent object is small, the technical scheme implemented based on the amplitude of the reflected signal in the prior art often has the problems of small signal-to-noise ratio, poor reliability, difficulty in adjustment and the like, which results in poor reliability of the sensor.

Disclosure of Invention

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

The specific technical scheme is as follows:

a photosensor for detecting transparent objects, comprising:

the receiving tube array is connected with a plurality of receiving tubes;

a light spot is formed on the receiving tube array by irradiating light, and the receiving tubes respectively generate a light intensity signal according to the light spot;

the sensor circuit is connected with the receiving tube array and generates an output signal according to each light intensity signal;

the processing device is connected with the sensor circuit and acquires the irradiation information of the light spot according to the output signal;

and the processing device judges whether the transparent object exists or not according to the irradiation information.

Preferably, the photoelectric sensor further comprises an emission tube for forming the irradiation light;

the transmitting tube and the receiving tube array are arranged on the same side, and the irradiating light reaches the receiving tube array from the transmitting tube through a reflecting surface;

or the transmitting tube and the receiving tube array are oppositely arranged.

Preferably, an emitting lens is arranged in front of the emitting tube, and the emitting lens processes the irradiating light so that the irradiating light forms an irradiating light spot in a specific arrangement;

and a receiving lens is arranged in front of the receiving tube array and used for focusing the irradiating light.

Preferably, the sensor circuit comprises:

the signal processing circuit is connected with the receiving tube array and generates the output signal according to the light intensity signal;

the time sequence circuit is connected with the receiving tube array and sends a time sequence signal to the receiving tube array;

the receiving tube array controls the light intensity signals generated by each receiving tube according to the time sequence signals to be sequentially input into the signal processing circuit.

Preferably, in the receiving tube array, the receiving tubes are arranged in the following manner: transversely or longitudinally or in a rectangular or polygonal or cross shape.

A method for detecting a transparent object, which is applied to the above photoelectric sensor, includes:

step S1: projecting irradiation light to a receiving tube array by adopting a transmitting tube so as to generate a light spot on the receiving tube array, and then respectively acquiring output signals corresponding to each receiving tube;

step S2: judging whether the transparent object exists on the propagation path of the irradiating light according to the output signal and comparison data generated in advance;

if yes, generating a detection signal, and then returning to the step S1;

if not, the process returns to the step S1.

Preferably, before the step S1, a comparative data collecting process is further included, which specifically includes:

step S01: projecting the irradiation light to the receiving tube array by using the transmitting tube to generate the light spots on the receiving tube array, and then respectively acquiring a plurality of output signals;

step S02: acquiring an illumination value corresponding to each receiving tube according to the output signal;

step S03: and generating illumination sequencing and average illumination according to the illumination values, and taking the illumination sequencing and the average illumination as the comparison data.

Preferably, the step S2 includes:

step S21: acquiring a current illumination value corresponding to each receiving tube according to the output signal;

step S22: judging whether the transparent object exists on the propagation path of the irradiation light according to the current illumination value and the comparison data;

if yes, generating the detection signal, and then returning to the step S1;

if not, the process returns to the step S1.

Preferably, the step S22 includes:

step A221: generating a current illumination sequence according to the current illumination value;

step A222: judging whether the sequence of the illumination values of the receiving tube changes or not according to the current illumination value sequence and the illumination sequence;

if yes, the transparent object is considered to be present on the propagation path of the irradiation light, the detection signal is generated, and then the step S1 is returned to;

if not, the transparent object is not considered to exist, and the step S1 is returned to.

Preferably, the step S22 includes:

step B221: generating current average illumination according to the current illumination value;

step B222: judging whether the illumination value of the receiving tube changes or not according to the current average illumination and the average illumination;

if yes, the transparent object is considered to be present on the propagation path of the irradiation light, the detection signal is generated, and then the step S1 is returned to;

if not, the transparent object is not considered to exist, and the process returns to the step S1.

The technical scheme has the following advantages or beneficial effects: through setting up a plurality of receiver tubes in order to constitute a receiver tube array, realized the detection to the facula that transparent object refraction back formed on the receiver tube array, and then effectively judge whether there is transparent object according to signal intensity, the distribution of refraction light on the receiver tube array that the refraction light leads to, improved the reliability of sensor.

Drawings

Embodiments of the present invention will now be described more fully hereinafter with reference to the accompanying drawings. The drawings are, however, to be regarded as illustrative and explanatory only and are not restrictive of the scope of the invention.

FIG. 1 is an overall schematic diagram of an embodiment of the present invention;

FIG. 2 is a schematic diagram of the connection between the sensor circuit and the processing device according to another embodiment of the present invention;

FIG. 3 shows an arrangement of transmitting and receiving tube arrays according to an embodiment of the present invention;

FIG. 4 is a diagram illustrating an arrangement of an array of transmitting tubes and receiving tubes according to another embodiment of the present invention;

FIG. 5 is a schematic diagram of an optical path according to an embodiment of the present invention;

FIG. 6 is a schematic diagram of the amplitude of the output signal of the receiving tube array in the embodiment of the present invention;

FIG. 7 is a schematic view of a lens according to an embodiment of the present invention;

FIG. 8 is a schematic diagram of a sensor circuit in an embodiment of the invention;

FIG. 9A is a schematic view of an embodiment of a receiver tube array;

FIG. 9B is a schematic view of an array of receiving tubes in accordance with another embodiment of the present invention;

FIG. 9C is a schematic view of an array of receiving tubes in accordance with another embodiment of the present invention;

FIG. 9D is a schematic view of an array of receiving tubes in accordance with another embodiment of the present invention;

FIG. 9E is a schematic view of an array of receiving tubes in accordance with another embodiment of the present invention;

FIG. 10 is a schematic diagram of a photosensor according to an embodiment of the present invention;

FIG. 11 is a schematic diagram of a detection method according to an embodiment of the present invention;

FIG. 12 is a schematic diagram of a comparative data collection process according to an embodiment of the present invention;

FIG. 13 is a diagram illustrating the substep of step S2 according to an embodiment of the present invention;

FIG. 14 is a diagram illustrating the substep of step S22 according to an embodiment of the present invention;

FIG. 15 is a diagram illustrating the substep of step S22 in accordance with an embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict.

The invention is further described with reference to the following drawings and specific examples, which are not intended to be limiting.

The invention includes:

a photoelectric sensor for detecting a transparent object, as shown in fig. 1, comprising:

the receiving tube array 1 is connected with a plurality of receiving tubes 11;

a light spot is formed on the receiving tube array 1 by a piece of irradiation light, and the receiving tubes 1 respectively generate a light intensity signal according to the light spot;

the sensor circuit 2 is connected with the receiving tube array 1, and the sensor circuit 2 respectively generates an output signal according to each light intensity signal;

the processing device 4 is connected with the sensor circuit 2, and the processing device 4 acquires the irradiation information of the light spots according to the output signals;

the processing device 4 determines whether or not a transparent object is present based on the irradiation information.

Specifically, to solve the problem in the prior art that the photoelectric sensor is low in reliability of detecting the transparent object by relying on amplitude attenuation of the receiving signal of the receiving tube, in this embodiment, the plurality of receiving tubes 11 form a receiving tube array, and the light intensity of the irradiated light received by each receiving tube 11 is obtained one by one, so as to obtain the projection light spot of the irradiated light on the receiving tube array 1. Irradiation information such as the area, the irradiation intensity and the position change of the projection light spot can be judged to effectively judge whether the irradiation light is refracted by a transparent object with different air density, so that the effective detection of the transparent object is realized, and the accuracy and the reliability of the detection are improved.

In practice, 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 irradiating light based on the photoelectric effect. A plurality of receiving tubes 11 form a receiving tube array 1, which is arranged in the photoelectric sensor. In one embodiment, the receiving tube array 1 further comprises a switch matrix, in which a plurality of controllable switches are disposed, each controllable switch being connected to a receiving tube 11, respectively, and being controlled by a control signal to select the light intensity signal inputted to the sensor circuit 2. The control signal may be a control signal generated by a photoelectric sensor through a specific computer program, or may be a timing signal. For example, in one embodiment, the switch matrix turns on and off the controllable switches sequentially under the control of the timing signals, 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 for amplifying, phase-locking, demodulating, and performing arithmetic processing on the received light intensity, thereby generating an output signal for representing the light intensity. The sensor circuits 2 are connected to the processing means 4 through respective communication ports. The processing device 4 may 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, Micro Controllers (MCUs), microprocessors (microprocessors), or other electronic components to realize the readout of the output signals and the detection of the transparent object according to the corresponding computer program. In an embodiment, the processing device 4 further has a switching value output port, and the processing device 4 is connected to an external switching tube through the switching value output port, so as to control the switching tube according to a detection result. To achieve better control of the external device, the processing device 4 may calculate the obtained output signal based on the prior art, for example, count the duration, the number of times, and the like of detecting the transparent object, so as to generate a corresponding output signal according to the actual needs of the user. In an embodiment, the processing means 4 may also be arranged as a control device of the sensor circuit 2, which sends corresponding control parameters, such as current-voltage conversion factor, transmitting tube transmitting power, etc., to the sensor circuit 2 via a corresponding communication protocol. In this embodiment, the processing means 4 effect the sending of the control parameters to the sensor circuit 2 and the receiving of the output signals sent by the sensor circuit 2 through the same communication port. In another embodiment, as shown in FIG. 2, the processing device 4 is provided with a bus communication port and an ALU port. The bus communication port is used for sending control parameters to the sensor circuit 2, and the ALU port is used for receiving the ALU output of the sensor circuit 2. The two communication modes can be set according to actual needs, and do not limit the actual technical scheme.

In a preferred embodiment, the photosensor further comprises one or more emission tubes 3, the emission tubes 3 being used to form the illumination light; the irradiation light may be a point-like light source, a linear light source, or a light source having a plurality of shapes such as a cross.

As shown in fig. 3 and 4, the emitting tube 3 is disposed on the same side as the receiving tube array 1, and the irradiated light reaches the receiving tube array 1 from the emitting tube 3 via a reflecting surface B;

alternatively, the transmitting tube 3 is disposed opposite to the receiving tube array 1.

Specifically, to the problem that the photoelectric sensor in the prior art can not adapt to the actual monitoring demand well, better monitoring effect has been realized through setting up transmitting tube 3 with receiving tube array 1 homonymy or subtend in this embodiment. For example, in an embodiment, for a larger monitoring area, the transmitting tube 3 and the receiving tube array 1 are arranged oppositely, so that a better monitoring effect on the transparent object a passing through a larger moving space is achieved. In another embodiment, for the transparent object a with a lower refractive index or a thinner thickness, the transmitting tube 3 and the receiving tube array 1 are arranged on the same side, so that the irradiating light generated by the transmitting tube 3 is refracted twice by the transparent object a in the reflection process, and the light spot generated on the receiving tube array 1 moves in a larger range, thereby improving the monitoring sensitivity.

In the implementation process, taking an embodiment in which the emitting tube 3 and the receiving tube array 1 are disposed on the same side as each other as an example, as shown in fig. 3, when there is no transparent object a between the emitting tube 3 and the receiving tube array 1, the illumination light generated by the emitting tube 3 is reflected by the reflecting surface B to project a light spot C on the receiving tube array 1. At this time, the processing device 4 reads the output signal of each receiving tube 11 and performs an operation to obtain the position of the spot C on the receiving tube array 1 at the current time. Subsequently, as shown in fig. 5, when the transparent object a exists between the transmitting tube 3 and the receiving tube array 1, the position of the light spot C on the receiving tube array 1 is shifted due to the refraction of the transparent object a by the irradiated light, so that the signals output by different receiving tubes 1 are changed. For example, in an embodiment, as shown in fig. 6, when there is no transparent object a, the curve D1 can be obtained by fitting the signal amplitudes output by the receiving tubes 11, and the center of the light spot C is near the fourth receiving tube according to the curve D1. When the transparent object a is present, the curve D2 can be obtained by fitting the amplitude of the signal output from each receiving tube 11. From the curve D2, the center of the spot C moves to the seventh receiving tube. Therefore, the presence or absence of the transparent object a can be effectively sensed by determining the movement of the light spot C.

In a preferred embodiment, as shown in fig. 7, an emission lens 31 is disposed in front of the emission tube 3, and the emission lens 31 processes the illumination light to make the illumination light form a specific arrangement of illumination spots; the receiving tube array 1 is provided with a receiving lens 12 in front, and the receiving lens 12 is used for focusing the irradiating light.

Specifically, to the problem that the photoelectric sensor in the prior art is difficult to effectively detect the transparent object a only through the received signal intensity, the irradiation light in the transmission process is focused by the arrangement of the transmitting lens 31 and the receiving lens 12 in the embodiment, so that the size of the light spot C formed by the irradiation light on the receiving tube array 1 is changed, the influence of the transparent object a on the transmission light path is further reflected, and the effective monitoring of the transparent object a is realized.

In practice, the emission lens 31 processes the irradiation light generated from the emission tube 3 so that the irradiation light emitted from the emission tube 3 to the surroundings is converted into parallel light by the emission lens 31 to form a desired irradiation spot. The irradiation light spots can form point-like light spots, linear light spots, cross-like light spots and the like according to the arrangement mode of different emission tubes 3 so as to meet the requirement of monitoring different types of transparent objects.

In a preferred embodiment, as shown in fig. 8, the sensor circuit 2 comprises:

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

the sequential circuit 22, the sequential circuit 22 connects the receiving tube array 1, the sequential circuit 22 sends a sequential signal to the receiving tube array 1;

the receiving tube array 1 controls the light intensity signal generated by each receiving tube 11 according to the time sequence signal and inputs the light intensity signal to the signal processing circuit in sequence.

Specifically, in order to achieve effective reception of the light intensity signals generated by the plurality of receiving tubes 11, in this embodiment, the timing circuit 22 is arranged to send the timing signals 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 signals. Meanwhile, the sequential circuit 22 also sends the same sequential signal to the signal processing circuit 21, so that the sequential circuit performs phase locking and demodulation according to the signal processing circuit, thereby realizing processing of the light intensity signal output by each receiving tube 11, and further enabling the processing device 4 to read out the illumination intensity of each receiving tube 11 according to the processed signal.

In a preferred embodiment, the signal processing circuit 21 further comprises:

the input end of the switched capacitor amplifier 211 is connected with the output end of the receiving tube array 1;

the input end of the sampling integration unit 212 is connected with the output end of the switched capacitor amplifier 211;

the input end of the signal processing unit 213 is connected to the output end of the sampling integration unit 212.

Specifically, in order to achieve a better processing effect on the light intensity signals output by the plurality of receiving tubes 11, in this embodiment, the switched capacitor amplifier 211, the sampling integration unit 212, and the signal processing unit 213 are sequentially arranged to implement the phase locking and demodulation processes according to the timing signals, so as to accurately process the light intensity signals output by each receiving tube 11.

In the implementation process, the switched capacitor amplifier 211 is a phase-locked amplifier implemented based on a switched capacitor technology, and performs a phase-locked process based on a 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 conversion gain, the sampling times and the integration time of the current-voltage are adjusted by the control parameters recorded in the register unit 6. The register unit 6 may be connected to an external control device via a bus protocol in the prior art to receive control parameters. According to actual needs, the register can realize the verification of the received control parameters by relying on the check bits or the check algorithm so as to realize better anti-interference performance. The signal processing unit 21 is an arithmetic logic circuit that performs operations such as addition, subtraction, multiplication, division, etc. on the received signal under adjustment of the control parameter, thereby generating an output signal for representing the intensity of illumination.

In a preferred embodiment, the sensor circuit 2 further includes a transmitting tube driving circuit 5, the transmitting tube driving circuit 5 is connected to the timing circuit 22 and one or more transmitting tubes 3, the transmitting tube driving circuit 5 drives the transmitting tubes 3 to generate the irradiating light under the control of the timing signal, so that the signal processing circuit 21 and the transmitting tube driving circuit 5 complete phase locking through the same timing signal.

In a preferred embodiment, as shown in fig. 9A, 9B, 9C, 9D, and 9E, in the receiving tube array 1, the receiving tubes 11 are arranged in the following manner: transversely or longitudinally or rectangularly or polygonally or crisscross.

Specifically, to the problem that the photoelectric sensor in the prior art cannot well meet the sensing requirements of different transparent objects, in this embodiment, the arrangement modes of the receiving tubes 11 in the receiving tube array 1 are adjusted, and the receiving tube arrays 1 in different arrangement modes respectively detect the movement of the light spot in the X-axis direction or the Y-axis direction in different scenes, so that a better sensing effect is achieved. For example, in an embodiment, a transparent object with a specific shape may cause a large displacement of a light spot in the X-axis direction, but the displacement in the Y-axis direction is not obvious, and at this time, a better detection effect on the object may be achieved by arranging a receiving tube array 1 arranged transversely.

As an alternative embodiment, the sensor circuit 2 can be implemented by a programmable sensor circuit, for example, CN202210103335.0 discloses a programmable photoelectric sensor, in which a circuit portion can be used for the sensor circuit 2. The programmable sensor circuit generally includes a register unit 6, and the register unit 6 is connected to an external upper computer through a communication protocol in the prior art, such as I2C, SPI, or a single-wire communication interface, so as to receive control parameters output by the external upper computer, and further perform parameter adjustment on components such as the switch capacitor amplifier 211, the sampling integration unit 212, the signal processing unit 213, the timing circuit 22, and the transmitting tube driving circuit 5, so that the sensor is more suitable for actual requirements. According to different actually set environments, a check algorithm can be added in the communication process, check bits can be set in the register unit 6, and a separate alarm circuit can be set to avoid the fault of register overturn caused by external electromagnetic interference. The upper computer and the processing device may be the same device, which respectively sends the control parameters through independent ports and receives the signals output by the sensor circuit 2, or sends the control parameters and receives the output signals through the same port. For example, in an embodiment, as shown in fig. 10, a receiving tube array 1, a sensor circuit 2, a transmitting tube driving circuit 5 and a register unit 6 are integrated in a photoelectric sensor, 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 further the sensor circuit 2 generates an output signal according to a light intensity signal generated by each receiving tube 11, so that the processing device 4 can acquire the movement of the light spot on the receiving tube array 1 according to the output signal, thereby determining whether a transparent object exists on the propagation path of the irradiation light.

As an alternative embodiment, the cross-shaped receiving tube array may be implemented by selecting a receiving tube array 1 having a specific central receiving tube. For example, CN202210139242.3 discloses a photoelectric sensor, wherein a receiving tube array can be used for the receiving tube array 1. The receiving tube array is provided with a first type of receiving tubes arranged in the horizontal direction and a vertical direction, and a second type of receiving tubes arranged in the central position. The second receiving tube is composed of four sub receiving tubes, the area of each sub receiving tube is one half of that of the first receiving tube, and the adjacent sub receiving tubes are connected in parallel along the horizontal direction or the vertical direction under the control of the control signal so as to form the first receiving tubes in two horizontal directions or the second receiving tubes in two vertical directions. Because the receiving tube array 1 can completely collect continuous output signals of a plurality of receiving tubes 11 with the same area in the horizontal direction and the vertical direction, the movement of light spots on the receiving tube array 1 is reflected by the light intensity variation trend of each receiving tube. Meanwhile, the receiving tubes 1 in the horizontal direction and the vertical direction are simultaneously controlled by setting two time sequence signals which are mutually searched by a phase, so that the acquisition of the illumination intensity in the horizontal direction and the vertical direction can be further realized, and the higher detection frequency is further realized.

A method for detecting a transparent object, which is applied to the above-mentioned photoelectric sensor, as shown in fig. 11, includes:

step S1: projecting irradiation light to the receiving tube array 1 by using a transmitting tube 3 to generate a light spot on the receiving tube array 1, and then respectively acquiring output signals corresponding to each receiving tube 11;

step S2: judging whether a transparent object exists on a propagation path of the irradiated light according to the output signal and comparison data generated in advance;

if yes, generating a detection signal, and then returning to the step S1;

if not, the process returns to step S1.

Specifically, to the problem that the photoelectric sensor in the prior art cannot effectively detect the transparent object only according to the signal attenuation amplitude, in this embodiment, the sensor array 1 is arranged to respectively acquire the output signal of each receiving tube 11, and then acquire the relevant information of the light spot on the current receiving tube array 1, including the irradiation intensity, the central position, the range, and the like, according to the output signal, and determine whether the transparent object exists according to the pre-generated comparison data, thereby avoiding the problem that the detection effect is not good due to the low light signal attenuation amplitude in the transparent object.

In practice, step S1 includes: the receiving tube array 1 is controlled by the timing signal, and then the output signal of each receiving tube 11 is received in sequence according to a specific sequence. Step S2 further includes: and calculating according to the output signal to obtain at least one parameter of the irradiation intensity, the central position and the light spot coverage range, and comparing according to the parameter and the comparison data to judge whether the transparent object exists.

In a preferred embodiment, before step S1, a comparative data collecting process is further included, as shown in fig. 12, which specifically includes:

step S01: projecting irradiation light to the receiving tube array 1 by using the transmitting tube 3 to generate light spots on the receiving tube array 1, and then respectively acquiring a plurality of output signals;

step S02: acquiring an illuminance value corresponding to each receiving tube 11 according to the output signal;

step S03: and generating illumination sorting and average illumination according to the illumination values, and taking the illumination sorting and the average illumination as comparison data.

Specifically, in the embodiment, for the problem that the transparent object cannot be detected well depending on the attenuation amplitude of the receiving signal in the prior art, by sequentially collecting the output signal of each receiving tube 11 and obtaining the illuminance value corresponding to each receiving tube 11 according to the output signal, the illuminance sequence and the average illuminance corresponding to the whole receiving tube array 1 are generated, so that the position and the intensity change of the light spot after the transparent object refracts the incident light are compared conveniently.

In practice, as shown in fig. 6, in this embodiment, there are 8 receiving tubes. Sorting according to the illumination values of the respective receiving tubes 11 may generate an illumination sort: { 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 average illuminance calculated from the illuminance value. Under the condition that no transparent object refracts, the central illumination of the light spots is larger than the edge illumination, so that the approximate position of the central point of the light spots can be reflected through illumination sequencing. When the illumination sequencing is changed, the central point of the light spot is changed, and the transparent object is shown to refract the illuminating light. Meanwhile, as can be seen from fig. 5, there is a fading phenomenon when the illumination light passes through the transparent object, and thus the average illumination is reduced. Therefore, the presence or absence of the transparent object can be determined at the same time by using the average illuminance as the comparison data.

In a preferred embodiment, as shown in fig. 13, step S2 includes:

step S21: acquiring a current illuminance value corresponding to each receiving tube 11 according to the output signal;

step S22: judging whether a transparent object exists on the propagation path of the irradiated light according to the current illuminance value and the comparison data;

if so, generating a detection signal, and then returning to the step S1;

if not, the process returns to step S1.

Specifically, in the present embodiment, by obtaining the current value corresponding to each receiving tube 11 and then generating the illumination rank and the average illumination corresponding to the whole receiving tube array, it is convenient to compare the position and intensity change of the light spot after the transparent object refracts the incident light, for the problem that the transparent object cannot be detected well depending on the attenuation amplitude of the receiving signal in the prior art.

In a preferred embodiment, as shown in fig. 14, step S22 includes:

step A221: generating a current illumination sequence according to the current illumination value;

step A222: judging whether the sequence of the illumination values of the receiving tube changes or not according to the current illumination value sequence and the illumination sequence;

if yes, a detection signal is generated considering that a transparent object is present on the propagation path of the irradiation light, and then the process returns to step S1;

if not, the process returns to step S1, assuming that no transparent object is present.

Specifically, aiming at the problem that the transparent object cannot be well detected depending on the attenuation amplitude of the received signal in the prior art, in the embodiment, the current illumination sequence is generated by obtaining the current illumination value, and the position of the light spot on the receiving tube array 1 is reflected, so that the detection of the transparent object is realized, and meanwhile, the problem that the transparent object cannot be well detected by singly detecting the signal intensity is avoided.

In operation, as shown in fig. 5, when the transparent object is present, the current illuminance sequence is changed to { seventh receiving pipe, sixth receiving pipe, fifth receiving pipe, eighth receiving pipe, fourth receiving pipe, third receiving pipe, second receiving pipe, first receiving pipe }. By comparing the current illumination sequencing with the illumination sequencing in the comparison data, whether the position of the light spot is changed or not can be effectively judged, and whether a transparent object which refracts the incident light exists or not is further judged.

In a preferred embodiment, as shown in fig. 15, step S22 includes:

step B221: generating current average illumination according to the current illumination value;

step B222: judging whether the illumination value of the receiving tube changes or not according to the current average illumination and the average illumination;

if yes, a detection signal is generated by considering that a transparent object exists on the propagation path of the irradiation light, and then the step returns to step S1;

if not, the process returns to step S1, assuming that no transparent object is present.

Specifically, to the problem that the transparent object cannot be effectively detected based on the single photoelectric sensor to detect the optical signal attenuation in the prior art, in this embodiment, a plurality of receiving tubes are arranged to generate the current average illumination, so that a better detection effect on the optical signal attenuation condition is achieved, and the detection sensitivity is improved.

In practice, the above detection methods may be used alternatively or simultaneously. For example, in an embodiment, only the change of the illumination sequence is detected to obtain the position change of the light spot refracted by the transparent object, so as to determine whether the transparent object exists. Or, in another embodiment, the photo sensor operates in a high reliability mode, and the processing device 4 determines whether there is a transparent object by simultaneously determining the change of the illumination sequence and the attenuation of the average illumination, thereby reducing the false alarm rate. For another example, in another embodiment, only the change of the current average illumination is detected, that is, whether a transparent object exists is determined by detecting the light attenuation caused by the transparent object.

The invention has the beneficial effects that: through setting up receiver tube array 1, detect the position, luminance, size isoparametric of the facula that the projection of transmitting tube 3 formed, and then effectively judge whether the illumination light is refracted by transparent object in the propagation, avoided prior art, the problem that transparent object is difficult to be detected is led to the light decay that transparent object caused less. Through the specific setting mode of adjusting transmitting tube 3 and receiving tube array 1, can change the detection scope, the light path setting of sensor to different measurement scenes and user's demand, and then realize better detection effect to all kinds of transparent objects. By arranging the programmable switched capacitor amplifier 211, the sampling integration unit 212, the signal processing unit 213, the sequential circuit 22 and the transmitting tube driving circuit 5, the effective adjustment of parameters such as current-voltage conversion multiple, transmitting tube transmitting power and the like is realized, the sensor is ensured not to be in a saturated state or in a state with smaller output signals, the sensitivity, the detection distance, the detection range and other parameters of the sensor can be conveniently changed according to the needs of users in actual application, and the sensor further meets the requirements of the users.

While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention.

Claims (10)

1. A photosensor for detecting transparent objects, comprising:

the receiving tube array is connected with a plurality of receiving tubes;

a light spot is formed on the receiving tube array by a piece of irradiation light, and the receiving tubes respectively generate a light intensity signal according to the light spot;

the sensor circuit is connected with the receiving tube array and generates an output signal according to each light intensity signal;

the processing device is connected with the sensor circuit and acquires the irradiation information of the light spot according to the output signal;

and the processing device judges whether the transparent object exists or not according to the irradiation information.

2. The photosensor of claim 1, further comprising an emitter tube for forming the illumination light;

the transmitting tube and the receiving tube array are arranged on the same side, and the irradiating light reaches the receiving tube array from the transmitting tube through a reflecting surface;

or the transmitting tube and the receiving tube array are oppositely arranged.

3. The photoelectric sensor as claimed in claim 2, wherein an emission lens is disposed in front of the emission tube, and the emission lens processes the illumination light to form a specific arrangement of illumination spots;

and a receiving lens is arranged in front of the receiving tube array and used for focusing the irradiating light.

4. The photosensor circuit of claim 1, wherein the sensor circuit comprises:

the signal processing circuit is connected with the receiving tube array and generates the output signal according to the light intensity signal;

the time sequence circuit is connected with the receiving tube array and sends a time sequence signal to the receiving tube array;

the receiving tube array controls the light intensity signals generated by each receiving tube according to the time sequence signals to be sequentially input into the signal processing circuit.

5. The photosensor of claim 1, wherein the receiving tubes in the array of receiving tubes are arranged in a manner that: transversely or longitudinally or rectangularly or polygonally or crisscross.

6. A method for detecting a transparent object, which is applied to the photoelectric sensor according to any one of claims 1 to 5, comprising:

step S1: projecting irradiation light to a receiving tube array by adopting a transmitting tube so as to generate a light spot on the receiving tube array, and then respectively acquiring output signals 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 comparison data generated in advance;

if yes, generating a detection signal, and then returning to the step S1;

if not, the process returns to the step S1.

7. The detecting method according to claim 6, wherein before the step S1, a comparative data collecting process is further included, specifically including:

step S01: projecting the irradiation light to the receiving tube array by using the transmitting tube to generate the light spots on the receiving tube array, and then respectively acquiring a plurality of output signals;

step S02: acquiring an illumination value corresponding to each receiving tube according to the output signal;

step S03: and generating illumination sequencing and average illumination according to the illumination values, and taking the illumination sequencing and the average illumination as the comparison data.

8. The detection method according to claim 7, wherein the step S2 includes:

step S21: obtaining a current illumination value corresponding to each receiving tube according to the output signal;

step S22: judging whether the transparent object exists on the propagation path of the irradiation light according to the current illumination value and the comparison data;

if yes, generating the detection signal, and then returning to the step S1;

if not, the process returns to the step S1.

9. The detection method according to claim 8, wherein the step S22 includes:

step A221: generating a current illumination sequence according to the current illumination value;

step A222: judging whether the sequence of the illumination values of the receiving tube changes or not according to the current illumination value sequence and the illumination sequence;

if yes, the transparent object is considered to be present on the propagation path of the irradiation light, the detection signal is generated, and then the step S1 is returned to;

if not, the transparent object is not considered to exist, and the process returns to the step S1.

10. The detecting method according to claim 8, wherein the step S22 includes:

step B221: generating current average illumination according to the current illumination value;

step B222: judging whether the illumination value of the receiving tube changes or not according to the current average illumination and the average illumination;

if yes, the transparent object is considered to be present on the propagation path of the irradiation light, the detection signal is generated, and then the step S1 is returned to;

if not, the transparent object is not considered to exist, and the process returns to the step S1.

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