A processing method and system for photoelectric sensor to prevent cross-light interference

Abstract

The present invention relates to the field of sensor anti-interference technology, and in particular to a processing method and system for photoelectric sensors to prevent cross-light interference, including: assigning a built-in code to each photoelectric sensor, each built-in code corresponds to a unique light-emitting period, and any two groups of light-emitting periods do not interfere with each other; making the designated photoelectric sensor emit light according to the light-emitting period corresponding to its built-in code, if the predicted code obtained based on the light signal reflected from the workpiece to the photoelectric sensor successfully matches the built-in code of the photoelectric sensor, then the photoelectric sensor is set to an enabled state, and then the light intensity data is monitored in real time, and when the photoelectric sensor is not interfered by an external same-frequency signal, if the detected light intensity data is greater than a second preset threshold, it means that the photoelectric sensor is operating normally and is not interfered by the cross-light signal. The present invention ensures stable and reliable operation of the sensor through precise coding and light intensity detection.

Description

Technical Field

[0001] The present invention relates to the technical field of sensor anti-interference, and in particular to a processing method and system for photoelectric sensors to prevent cross-light interference. Background Art

[0002] A photoelectric sensor is a sensor that uses a photoelectric element as a detection element. It converts the changes in the measured value into changes in light signals and further converts the light signals into electrical signals.

[0003] like Figure 1 As shown in the figure, in actual applications, photoelectric sensors are often susceptible to interference from other light sources (including light emitted by equipment or light from other sensors) due to the complexity of various detection requirements. Once these external light signals enter the photoelectric sensor, they may cause the sensor to misjudge, resulting in deviations in the detection results. In addition, due to the differences in the emissivity of different workpieces, photoelectric sensors may face stability issues during the detection process, making it difficult to ensure accurate and reliable measurement results.

[0004] With the miniaturization of equipment and the diversification of detection requirements, multiple photoelectric sensors often need to be closely integrated together. However, this layout aggravates the crosstalk phenomenon, making the photoelectric sensors more susceptible to interference. These interferences not only affect the stability of the sensor, but may also cause it to malfunction, thus affecting the accuracy and reliability of the entire detection system. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides a processing method for photoelectric sensors to prevent crosstalk interference, comprising the following steps:

[0006] S1: Establish an address code database, which is used to store multiple built-in codes, each of which is an n-bit number randomly generated from 0 and 1. Each photoelectric sensor is assigned a built-in code, each built-in code corresponds to a unique light-emitting period, and any two groups of light-emitting periods do not interfere with each other;

[0007] S2: Control the designated photoelectric sensor to emit light according to the light emission cycle corresponding to its built-in code, and match the predicted code obtained based on the light signal reflected from the workpiece to the photoelectric sensor with the built-in code of the photoelectric sensor:

[0008] If the match is not successful, after waiting for a light-emitting cycle corresponding to a built-in code, return to S1 and reassign a built-in code to the photoelectric sensor for code matching until the match is successful;

[0009] If the match is successful, the photoelectric sensor is set to an enabled state, and then the light intensity data is monitored in real time. According to the comparison result between the light intensity data and the first preset threshold, it is determined whether the photoelectric sensor is interfered by an external same-frequency signal:

[0010] If yes, return to S1;

[0011] If not, further determine whether the detected light intensity data is greater than a second preset threshold: if not, return to S1; if yes, it means that the photoelectric sensor is working normally and is not interfered by the crosstalk signal.

[0012] In one embodiment of the present invention, the method for obtaining the predictive coding includes:

[0013] Collecting first light intensity data X received when the photoelectric sensor itself emits light and second light intensity data Y received when the photoelectric sensor itself does not emit light, and opening a sequence space before the built-in encoding, the sequence space is used to store the first light intensity data X and the second light intensity data Y;

[0014] Obtaining a light intensity difference when there is no external light according to the first light intensity data X and the second light intensity data Y, and determining the first preset threshold based on the light intensity difference;

[0015] Control the designated photoelectric sensor to emit light according to the light-emitting period corresponding to its built-in code, collect light intensity data of the photoelectric sensor for multiple times in a predetermined timing, encode the collected light intensity data according to the first preset threshold value, and obtain a sampling code sequence with the same number of bits as the built-in code, namely the predicted code.

[0016] In one embodiment of the present invention, the method for encoding the collected light intensity signal according to the first preset threshold is: the point where the difference between the collected light intensity data and the second light intensity data Y is greater than the first preset threshold is recorded as 1, and the point where the difference between the collected light intensity signal and the second light intensity data Y is less than or equal to the first preset threshold is recorded as 0.

[0017] In one embodiment of the present invention, the calculation formula of the first preset threshold K1 is:

[0018] K1=(XY)×α1+Y, α1∈[0.6,1] is the preset parameter.

[0019] In one embodiment of the present invention, a method for determining whether a photoelectric sensor is interfered by an external co-frequency signal according to a comparison result between the light intensity data and a first preset threshold value includes:

[0020] The successfully matched photoelectric sensor is made to emit light in the presence of a workpiece, and light intensity signals are collected for multiple times in succession, and the collected light intensity signals are encoded in time sequence according to the first preset threshold value to obtain a prediction code with the same number of bits as the built-in code;

[0021] Verify and compare the predicted code with the built-in code of the photoelectric sensor: if the verification is successful, wait for the photoelectric sensor to work normally until the detected light intensity data is less than the second preset threshold, and then return to S1; otherwise, return to S1 and re-assign a built-in code to the photoelectric sensor;

[0022] Among them, the method for obtaining a predicted code with the same number of bits as the built-in code includes: continuously collecting multiple groups of first light intensity data M reflected to the photoelectric sensor when there is a workpiece, marking the point where the difference between the first light intensity data M and the second light intensity data N reflected to the photoelectric sensor when there is no workpiece is greater than the first preset threshold as 1, marking the point where the difference between the first light intensity data M and the second light intensity data N is less than or equal to the first preset threshold as 0, and sorting them by time to obtain a predicted code with the same number of bits as the built-in code.

[0023] In one embodiment of the present invention, the calculation formula of the second preset threshold K2 is:

[0024] K2=(MN)×α2+N,

[0025] Wherein, M is the first light intensity data reflected to the photoelectric sensor when there is a workpiece, N is the second light intensity data reflected to the photoelectric sensor when there is no workpiece, and α2∈[0.8,1] is a preset parameter.

[0026] In one embodiment of the present invention, it also includes: controlling the conduction of the optical signal of the photoelectric sensor in real time through a signal amplification circuit or a filtering device, so that the receiving signal consistent with the timing of the photoelectric sensor's own light-emitting signal passes through, and intercepting the non-co-frequency or multiplied frequency interference signal of the photoelectric sensor.

[0027] Based on the same inventive concept, the present invention also provides a processing system for photoelectric sensors to prevent cross-light interference, the system is used to implement the processing method for photoelectric sensors to prevent cross-light interference, and specifically includes the following modules:

[0028] An address code allocation module is used to establish an address code database, wherein the address code database is used to store multiple built-in codes, each of which is an n-bit number randomly generated from 0 and 1. A built-in code is allocated to each photoelectric sensor, each built-in code corresponds to a unique light-emitting period, and any two groups of light-emitting periods do not interfere with each other;

[0029] The external co-frequency interference signal filtering module is used to make the specified photoelectric sensor emit light according to the lighting cycle corresponding to its built-in code, and match the predicted code obtained based on the light signal reflected from the workpiece to the photoelectric sensor with the built-in code of the photoelectric sensor:

[0030] If the match is not successful, after waiting for a light-emitting cycle corresponding to a built-in code, return to S1 and reassign a built-in code to the photoelectric sensor for code matching until the match is successful;

[0031] If the match is successful, the photoelectric sensor is set to an enabled state, and then the light intensity data is monitored in real time. According to the comparison result between the light intensity data and the first preset threshold, it is determined whether the photoelectric sensor is interfered by an external same-frequency signal:

[0032] If yes, return to S1;

[0033] If not, further determine whether the detected light intensity data is greater than a second preset threshold: if not, return to S1; if yes, it means that the photoelectric sensor is working normally and is not interfered by the crosstalk signal.

[0034] In one embodiment of the present invention, the system also includes a non-co-frequency or doubled frequency interference signal filtering module, which is used to control the conduction of the optical signal of the photoelectric sensor in real time through a signal amplification circuit or a filtering device, so that the received signal consistent with the timing of the photoelectric sensor's own light signal passes through, thereby intercepting the non-co-frequency or doubled frequency interference signal of the photoelectric sensor.

[0035] The present invention also provides a photoelectric sensor, which utilizes the processing system for preventing cross-light interference in the photoelectric sensor to filter out the received cross-light interference signal.

[0036] The above technical solution of the present invention has the following advantages compared with the prior art:

[0037] The present invention achieves unique adjustment of sensor timing by introducing its own address number recognition technology, effectively avoiding mutual interference between sensors. At the same time, combined with the judgment mechanism of external intensity light, it can accurately identify and eliminate light interference. Furthermore, the present invention also uses the consistency of the proportional relationship of light intensity change to reduce the impact of different workpiece reflectivity on detection accuracy. This innovative design enables the sensor to detect objects stably and accurately without being interfered by external crosstalk, greatly improving the performance and reliability of the sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below according to specific embodiments of the present invention in conjunction with the accompanying drawings, wherein

[0039] Figure 1 This is a schematic diagram of a photoelectric sensor being interfered by crosstalk;

[0040] Figure 2 It is a flowchart of a processing method for preventing cross-light interference in a photoelectric sensor provided in an embodiment of the present invention;

[0041] Figure 3 is a flow chart of a method for obtaining a predictive code based on an optical signal reflected from a workpiece to a photoelectric sensor provided in an embodiment of the present invention;

[0042] Figure 4 It is a principle diagram of filtering interference signals of non-co-frequency or multiplied frequency using a signal amplification circuit or a filtering device provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0043] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0044] Embodiment 1

[0045] Reference Figure 2 As shown, the present invention provides a processing method for photoelectric sensors to prevent cross-light interference, comprising the following steps:

[0046] S1: Establish an address code database at the MCU control end, the address code database is used to store multiple built-in codes, each built-in code is an n-bit number randomly generated from 0 and 1, the control end assigns a built-in code to each photoelectric sensor, each built-in code corresponds to a unique light-emitting cycle, and any two groups of light-emitting cycles do not interfere with each other;

[0047] S2: The MCU control terminal controls the designated photoelectric sensor to emit light according to the light emission cycle corresponding to its built-in code, and matches the predicted code obtained based on the light signal reflected from the workpiece to the photoelectric sensor with the built-in code of the photoelectric sensor:

[0048] If the match is not successful, after waiting for a light-emitting cycle corresponding to a built-in code, return to S1 and reassign a built-in code to the photoelectric sensor for code matching until the match is successful;

[0049] If the match is successful, the photoelectric sensor is set to an enabled state, and then the light intensity data is monitored in real time. According to the comparison result between the light intensity data and the first preset threshold, it is determined whether the photoelectric sensor is interfered by an external same-frequency signal:

[0050] If yes, return to S1;

[0051] If not, further determine whether the detected light intensity data is greater than a second preset threshold: if not, return to S1; if yes, it means that the photoelectric sensor is working normally and is not interfered by the crosstalk signal.

[0052] It can be seen from the above technical solutions that the present invention can ensure that each photoelectric sensor has a unique built-in code and light-emitting cycle, thereby effectively solving the problem of cross-light interference that may occur between photoelectric sensors and improving the detection accuracy and reliability of the photoelectric sensors.

[0053] Specifically, in step S1, in order to avoid cross-light interference, a random function is used to generate multiple non-repetitive built-in codes, and a built-in code is assigned to each photoelectric sensor. The built-in code of each sensor is unique, and each built-in code corresponds to a unique light-emitting period, as shown in Table 1 below.

[0054] Table 1

[0055] Middle 12-bit code Corresponding period T 100000000000 T0 100000000001 T1 100000000010 T2 100000000011 T3 100000000100 T4 100000000101 T5 100000000110 T6 100000000111 T7 100000001000 T8 100000001001 T9 100000001010 T10 … …

[0056] In step S2, based on the light signal reflected by the workpiece to the photoelectric sensor, the control end receives the light signal and encodes the light signal to obtain a prediction code. Figure 3 As shown, the method for obtaining the predictive code specifically includes:

[0057] S201: collecting first light intensity data X received when the photoelectric sensor itself emits light and second light intensity data Y received when the photoelectric sensor itself does not emit light, and opening a sequence space before the built-in encoding, the sequence space is used to store the first light intensity data X and the second light intensity data Y;

[0058] S202: obtaining a light intensity difference when there is no external light according to the first light intensity data X and the second light intensity data Y, and determining the first preset threshold based on the light intensity difference;

[0059] S203: Make the designated photoelectric sensor emit light according to the light-emitting period corresponding to its built-in code, collect light intensity data of the photoelectric sensor for multiple times in a predetermined timing, encode the collected light intensity data according to the first preset threshold value, and obtain a sampling code sequence with the same number of bits as the built-in code, namely, the predicted code.

[0060] In this embodiment, the method for encoding the collected light intensity signal according to the first preset threshold is: the point where the difference between the collected light intensity data and the second light intensity data Y is greater than the first preset threshold is recorded as 1, and the point where the difference between the collected light intensity signal and the second light intensity data Y is less than or equal to the first preset threshold is recorded as 0. The calculation formula of the first preset threshold K1 is K1=(XY)×α1+Y, and α1∈[0.6,1] is a preset parameter.

[0061] Further, according to the comparison result of the light intensity data and the first preset threshold, the method for judging whether the photoelectric sensor is interfered by the external same-frequency signal includes:

[0062] The successfully matched photoelectric sensor is made to emit light in the presence of a workpiece, and light intensity signals are collected for multiple times in succession, and the collected light intensity signals are encoded in time sequence according to the first preset threshold value to obtain a prediction code with the same number of bits as the built-in code;

[0063] Verify and compare the predicted code with the built-in code of the photoelectric sensor: if the verification is successful, wait for the photoelectric sensor to work normally until the detected light intensity data is less than the second preset threshold, and then return to S1; otherwise, return to S1 and re-assign a built-in code to the photoelectric sensor;

[0064] Among them, the method for obtaining a predicted code with the same number of bits as the built-in code includes: continuously collecting multiple groups of first light intensity data M reflected to the photoelectric sensor when there is a workpiece, marking the point where the difference between the first light intensity data M and the second light intensity data N reflected to the photoelectric sensor when there is no workpiece is greater than the first preset threshold as 1, marking the point where the difference between the first light intensity data M and the second light intensity data N is less than or equal to the first preset threshold as 0, and sorting them by time to obtain a predicted code with the same number of bits as the built-in code.

[0065] In this embodiment, the calculation formula of the second preset threshold K2 is:

[0066] K2=(MN)×α2+N,

[0067] Wherein, M is the first light intensity data reflected to the photoelectric sensor when there is a workpiece, N is the second light intensity data reflected to the photoelectric sensor when there is no workpiece, and α2∈[0.8,1] is a preset parameter.

[0068] In this embodiment, it also includes: setting a signal amplifying circuit or filtering device at the MCU control end, controlling the conduction of the optical signal of the photoelectric sensor in real time through the signal amplifying circuit or filtering device, allowing the receiving signal consistent with the timing of the photoelectric sensor's own light-emitting signal to pass, and intercepting the interference signal of the photoelectric sensor that is not of the same frequency or multiplied frequency, such as Figure 4This interference signal hardware filtering method can be implemented by setting a time window or a synchronous trigger mechanism in the signal processing circuit to ensure that only signals received within the correct time period are further processed, further improving the system's anti-interference ability and signal quality.

[0069] With the synergistic effect of the interference signal hardware filtering method and the above-mentioned co-frequency interference signal filtering method, the detection accuracy of the photoelectric sensor will also be enhanced accordingly.

[0070] Embodiment 2

[0071] Based on the same inventive concept as that of the first embodiment, the present invention further provides a processing system for photoelectric sensors to prevent cross-light interference. The system is used to implement the processing method for photoelectric sensors to prevent cross-light interference described in the first embodiment, and specifically includes the following modules:

[0072] An address code allocation module is used to establish an address code database, wherein the address code database is used to store multiple built-in codes, each of which is an n-bit number randomly generated from 0 and 1. A built-in code is allocated to each photoelectric sensor, each built-in code corresponds to a unique light-emitting period, and any two groups of light-emitting periods do not interfere with each other;

[0073] The external co-frequency interference signal filtering module is used to control the specified photoelectric sensor to emit light according to the lighting cycle corresponding to its built-in code, and match the predicted code obtained based on the light signal reflected from the workpiece to the photoelectric sensor with the built-in code of the photoelectric sensor:

[0074] If the match is not successful, after waiting for a light-emitting cycle corresponding to a built-in code, return to S1 and reassign a built-in code to the photoelectric sensor for code matching until the match is successful;

[0075] If the match is successful, the photoelectric sensor is set to an enabled state, and then the light intensity data is monitored in real time. According to the comparison result between the light intensity data and the first preset threshold, it is determined whether the photoelectric sensor is interfered by an external same-frequency signal:

[0076] If yes, return to S1;

[0077] If not, further determine whether the detected light intensity data is greater than a second preset threshold: if not, return to S1; if yes, it means that the photoelectric sensor is working normally and is not interfered by the crosstalk signal.

[0078] In this embodiment, the system also includes a non-co-frequency or doubled frequency interference signal filtering module, which is used to control the conduction of the optical signal of the photoelectric sensor in real time through a signal amplification circuit or a filtering device, so that the received signal consistent with the timing of the photoelectric sensor's own light signal passes through, thereby intercepting the non-co-frequency or doubled frequency interference signal of the photoelectric sensor.

[0079] Embodiment 3

[0080] The present invention further provides a photoelectric sensor, which uses the processing system for photoelectric sensor to prevent cross-light interference described in the second embodiment to filter out the received cross-light interference signal.

[0081] Obviously, the above embodiments are merely examples for clear explanation and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from these are still within the protection scope of the invention.

Claims

1. A method for preventing crosstalk interference in a photoelectric sensor, characterized in that: The following steps are involved: S1: Establish an address code database, which is used to store multiple built-in codes, each of which is an n-bit number randomly generated from 0 and 1. Each photoelectric sensor is assigned a built-in code, each built-in code corresponds to a unique light-emitting period, and any two groups of light-emitting periods do not interfere with each other; S2: Control the designated photoelectric sensor to emit light according to the light emission cycle corresponding to its built-in code, and match the predicted code obtained based on the light signal reflected from the workpiece to the photoelectric sensor with the built-in code of the photoelectric sensor: If the match is not successful, after waiting for a light-emitting cycle corresponding to a built-in code, return to S1 and reassign a built-in code to the photoelectric sensor for code matching until the match is successful; If the match is successful, the photoelectric sensor is set to an enabled state, and then the light intensity data is monitored in real time. According to the comparison result between the light intensity data and the first preset threshold, it is determined whether the photoelectric sensor is interfered by an external same-frequency signal: If yes, return to S1; If not, further determine whether the detected light intensity data is greater than a second preset threshold value: if not, return to S1; if yes, it means that the photoelectric sensor works normally and is not interfered by the crosstalk signal; Wherein, in step S2, the method for obtaining the prediction code includes: Collecting first light intensity data X received when the photoelectric sensor itself emits light and second light intensity data Y received when the photoelectric sensor itself does not emit light, and opening a sequence space before the built-in encoding, the sequence space is used to store the first light intensity data X and the second light intensity data Y; Obtaining a light intensity difference when there is no external light according to the first light intensity data X and the second light intensity data Y, and determining the first preset threshold based on the light intensity difference; The designated photoelectric sensor is made to emit light according to the light emission period corresponding to the built-in code, and the light intensity data of the photoelectric sensor is continuously collected multiple times according to a predetermined time sequence, and the collected light intensity data is encoded according to the first preset threshold value to obtain a sampling code sequence with the same number of bits as the built-in code, i.e., the predicted code; In step S2, according to the comparison result of the light intensity data and the first preset threshold, the method for determining whether the photoelectric sensor is interfered by an external same-frequency signal includes: The successfully matched photoelectric sensor is made to emit light in the presence of a workpiece, and light intensity signals are collected for multiple times in succession, and the collected light intensity signals are encoded in time sequence according to the first preset threshold value to obtain a prediction code with the same number of bits as the built-in code; Verify and compare the predicted code with the built-in code of the photoelectric sensor: if the verification is successful, wait for the photoelectric sensor to work normally until the detected light intensity data is less than the second preset threshold, and then return to S1; otherwise, return to S1 and re-assign a built-in code to the photoelectric sensor; Wherein, the method for obtaining a prediction code with the same number of bits as the built-in code includes: continuously collecting multiple groups of first light intensity data M reflected to the photoelectric sensor when there is a workpiece, marking the point where the difference between the first light intensity data M and the second light intensity data N reflected to the photoelectric sensor when there is no workpiece as 1, marking the point where the difference between the first light intensity data M and the second light intensity data N is less than or equal to the first preset threshold as 0, and obtaining a prediction code with the same number of bits as the built-in code by sorting in time; The first preset threshold The calculation formula is , is the preset parameter; The second preset threshold The calculation formula is: , Wherein, M is the first light intensity data reflected to the photoelectric sensor when there is a workpiece, and N is the second light intensity data reflected to the photoelectric sensor when there is no workpiece. are preset parameters.

2. The method for preventing crosstalk interference in a photoelectric sensor according to claim 1, characterized in that: The method for encoding the collected light intensity signal according to the first preset threshold is: the point where the difference between the collected light intensity data and the second light intensity data Y is greater than the first preset threshold is recorded as 1, and the point where the difference between the collected light intensity signal and the second light intensity data Y is less than or equal to the first preset threshold is recorded as 0.

3. The method for preventing crosstalk interference in a photoelectric sensor according to claim 1, characterized in that: Also includes: The conduction of the optical signal of the photoelectric sensor is controlled in real time through the signal amplification circuit or filtering device, so that the receiving signal consistent with the timing of the photoelectric sensor's own light-emitting signal can pass through, and the interference signal of the photoelectric sensor that is not of the same frequency or doubled frequency can be intercepted.

4. A processing system for photoelectric sensors to prevent crosstalk interference, characterized in that: The system is used to implement the processing method for preventing cross-light interference of a photoelectric sensor according to any one of claims 1 to 3, and specifically includes the following modules: An address code allocation module is used to establish an address code database, wherein the address code database is used to store multiple built-in codes, each of which is an n-bit number randomly generated from 0 and 1. A built-in code is allocated to each photoelectric sensor, each built-in code corresponds to a unique light-emitting period, and any two groups of light-emitting periods do not interfere with each other; The external co-frequency interference signal filtering module is used to control the specified photoelectric sensor to emit light according to the lighting cycle corresponding to its built-in code, and match the predicted code obtained based on the light signal reflected from the workpiece to the photoelectric sensor with the built-in code of the photoelectric sensor: If the match is not successful, after waiting for a light-emitting cycle corresponding to a built-in code, return to S1 and reassign a built-in code to the photoelectric sensor for code matching until the match is successful; If the match is successful, the photoelectric sensor is set to an enabled state, and then the light intensity data is monitored in real time. According to the comparison result between the light intensity data and the first preset threshold, it is determined whether the photoelectric sensor is interfered by an external same-frequency signal: If yes, return to S1; If not, further determine whether the detected light intensity data is greater than a second preset threshold: if not, return to S1; if yes, it means that the photoelectric sensor is working normally and is not interfered by the crosstalk signal.

5. The processing system for preventing crosstalk interference of a photoelectric sensor according to claim 4, characterized in that: The system also includes a non-co-frequency or doubled frequency interference signal filtering module, which is used to control the conduction of the optical signal of the photoelectric sensor in real time through a signal amplification circuit or a filtering device, so that the received signal consistent with the timing of the photoelectric sensor's own light signal passes through, and intercepts the non-co-frequency or doubled frequency interference signal of the photoelectric sensor.

6. A photoelectric sensor, characterized in that: The received cross-light interference signal is filtered out by using the processing system for preventing cross-light interference in a photoelectric sensor as claimed in claim 4 or claim 5.

Images