A through-beam photoelectric sensor and its anti-interference method

Abstract

The present invention belongs to the field of sensor technology, and discloses a through-beam photoelectric sensor and an anti-interference method thereof, wherein the sensor comprises: a first control module, for generating a coding signal; a transmitting circuit, connected to the first control module, for transmitting a light signal according to the coding signal; a receiving circuit, for receiving the light signal transmitted by the transmitting circuit, and generating a voltage signal; a second control module, connected to the receiving circuit, for generating a check signal corresponding to the coding signal; the second control module controls the receiving circuit whether to receive the light signal transmitted by the transmitting circuit according to the matching result of the check signal and the voltage signal, if the check signal matches the voltage signal, the second control module controls the receiving circuit to continue to receive the light signal transmitted by the transmitting circuit, if the check signal does not match the voltage signal, the second control module controls the receiving circuit to no longer receive the light signal transmitted by the transmitting circuit. The present invention can effectively improve the stability and anti-interference of the through-beam photoelectric sensor.

Description

Technical Field

[0001] The invention belongs to the technical field of sensors, and in particular relates to a through-beam photoelectric sensor and an anti-interference method thereof. Background Art

[0002] The through-beam photoelectric sensor is a photoelectric sensor that relies on emitting infrared rays. It has two parts, the emitting part and the receiving part. It uses invisible infrared light as a medium to emit an adjustable pulse beam directly to the receiving body, and then receives and converts the control output. It can reach medium and long distances. This product is widely used in the warehousing and logistics industry, automated equipment inspection, and security monitoring, and is usually achieved using long-distance through-beam photoelectric sensors.

[0003] Traditional photoelectric sensors have many electronic components and complex circuits. They can only work in environments with relatively little interference, and other photoelectric sensors cannot be installed nearby. Otherwise, the signals between sensors will interfere with each other, making it impossible to identify whether the signal is sent correctly. They can only be processed as valid signals, resulting in poor reliability and easy misoperation.

[0004] Based on this, the art urgently needs a through-beam photoelectric sensor and an anti-interference method thereof to solve the above technical problems. Summary of the invention

[0005] In view of this, an object of the present invention is to solve the above-mentioned problem and provide a through-beam photoelectric sensor and an anti-interference method thereof.

[0006] In order to solve the above technical problems, the present invention provides a through-beam photoelectric sensor, comprising:

[0007] A first control module, used to generate a coded signal;

[0008] a transmitting circuit, connected to the first control module, and configured to transmit an optical signal according to the coded signal;

[0009] A receiving circuit, used for receiving the optical signal transmitted by the transmitting circuit and generating a voltage signal;

[0010] a second control module, connected to the receiving circuit, and configured to generate a check signal corresponding to the coded signal;

[0011] The second control module controls whether the receiving circuit receives the optical signal emitted by the transmitting circuit according to the matching result between the verification signal and the voltage signal. If the verification signal matches the voltage signal, the second control module controls the receiving circuit to continue receiving the optical signal emitted by the transmitting circuit. If the verification signal does not match the voltage signal, the second control module controls the receiving circuit to no longer receive the optical signal emitted by the transmitting circuit.

[0012] As a further improvement of the present invention, the first control module includes:

[0013] a first processor, wherein a second pin of the first processor is connected to the transmitting circuit, and the first processor is used to send the coded signal to the transmitting circuit;

[0014] a first voltage regulating circuit, the voltage regulating circuit being connected to the first processor, and the voltage regulating circuit being used to regulate a voltage so that the first processor transmits a coded signal corresponding to the voltage;

[0015] A first reset circuit, used for resetting the first processor so that the first processor starts running from an initial state;

[0016] A first power supply circuit is connected to a ninth pin of the first processor and is used to supply power to the first processor.

[0017] As a further improvement of the present invention, the first voltage regulating circuit includes a potentiometer, a first connection end of the potentiometer is connected to the voltage end, a second connection end of the potentiometer is connected to the twelfth pin of the first processor, and a third connection end of the potentiometer is grounded.

[0018] As a further improvement of the present invention, the transmitting circuit includes a first resistor, a second resistor, a third resistor, a first capacitor, a first light emitting diode and a first MOS tube;

[0019] The voltage terminal is connected to one end of the first capacitor through the first resistor, the other end of the first capacitor is grounded, and the first resistor is connected to the anode of the first light-emitting diode;

[0020] The second resistor connects the gate of the first MOS tube and the second pin of the first processor, the source of the first MOS tube is grounded through the third resistor, and the drain of the first MOS tube is connected to the cathode of the first light-emitting diode.

[0021] As a further improvement of the present invention, the second control module includes:

[0022] a second processor, wherein a third pin of the second processor is connected to the receiving circuit, and the second processor is used to control whether the receiving circuit receives the optical signal transmitted by the transmitting circuit;

[0023] A second reset circuit, used for resetting the second processor so that the second processor starts running from an initial state;

[0024] A second power supply circuit is connected to a ninth pin of the second processor and is used to supply power to the second processor.

[0025] As a further improvement of the present invention, the receiving circuit includes a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor, a thirteenth resistor, a fourteenth resistor, a second capacitor, a third capacitor, a fourth capacitor, a fifth capacitor, a sixth capacitor, a seventh capacitor, an optical coupler, a first operational amplifier, and a second operational amplifier;

[0026] The voltage terminal is grounded through the fourth resistor and the second capacitor, and the fourth resistor and the second capacitor are connected in series;

[0027] The first pin of the optocoupler is connected to the fifth resistor through the third capacitor, the third capacitor is connected in series with the fifth resistor, the other end of the fifth resistor is connected to the non-inverting input terminal of the first operational amplifier, the first pin of the optocoupler is grounded through the sixth resistor, the first pin of the optocoupler is grounded through the third capacitor and the seventh resistor, the third capacitor is connected in series with the seventh resistor, the second pin of the optocoupler is connected to the voltage terminal through the fourth resistor, and the second pin of the optocoupler is grounded through the second capacitor;

[0028] The inverting input terminal of the first operational amplifier is grounded through the eighth resistor and the fourth capacitor, the eighth resistor and the fourth capacitor are connected in series, the inverting input terminal of the first operational amplifier is connected to the output terminal of the first operational amplifier through the fifth capacitor and the ninth resistor, the fifth capacitor and the ninth resistor are connected in parallel, the output terminal of the first operational amplifier is connected to the tenth resistor through the sixth capacitor, the other end of the tenth resistor is connected to the non-inverting input terminal of the second operational amplifier, the power supply pin of the first operational amplifier is connected to the voltage terminal, the power supply pin of the first operational amplifier is grounded through the seventh capacitor, and the ground terminal of the first operational amplifier is grounded;

[0029] The inverting input terminal of the second operational amplifier is connected to the voltage terminal through the eleventh resistor, the inverting input terminal of the second operational amplifier is grounded through the twelfth resistor, the non-inverting input terminal of the second operational amplifier is connected to the output terminal of the second operational amplifier through the thirteenth resistor, the non-inverting input terminal of the second operational amplifier is grounded through the tenth resistor and the fourteenth resistor, the tenth resistor and the fourteenth resistor are connected in series, and the output terminal of the second operational amplifier is connected to the third pin of the second processor.

[0030] As a further improvement of the present invention, the second control module further includes a protection circuit, and the protection circuit includes a fifteenth resistor, a sixteenth resistor, a seventeenth resistor, an eighteenth resistor, a first transistor, a second transistor, a first diode and a connector;

[0031] The voltage end is connected to one end of the sixteenth resistor, and the other end of the sixteenth resistor is connected to the collector of the second transistor;

[0032] The tenth pin of the second processor is connected to the base of the second transistor, the emitter of the second transistor is grounded, and the collector of the second transistor is connected to the base of the first transistor through the seventeenth resistor;

[0033] The collector of the first transistor is connected to the connector through the first diode, and the collector of the first transistor is grounded through the eighteenth resistor;

[0034] The sixteenth pin of the second processor is connected to the base of the first transistor through the fifteenth resistor.

[0035] As a further improvement of the present invention, the coded signal is a binary coded signal.

[0036] The present invention also provides an anti-interference method for a through-beam photoelectric sensor, comprising:

[0037] Acquire a coded signal, and emit an optical signal according to the coded signal;

[0038] receiving the optical signal and generating a voltage signal;

[0039] generating a check signal corresponding to the coded signal;

[0040] It is determined whether the verification signal matches the voltage signal. If so, the optical signal continues to be received. If not, the optical signal is no longer received.

[0041] As a further improvement of the present invention, before the step of transmitting the optical signal according to the coded signal, the step further includes:

[0042] upon receiving the coded signal, adjusting a voltage corresponding to the coded signal;

[0043] A transmission pulse corresponding to the voltage is transmitted according to the voltage.

[0044] Compared with the prior art, the present invention provides a through-beam photoelectric sensor and method. By using a transmitting circuit to transmit a light signal according to a coding signal before the sensor receives the light signal, and by using a matching mechanism of a verification signal and a voltage signal, it is possible to effectively detect and eliminate misjudgments caused by interference, noise or transmission errors, thereby ensuring that the received light signal is reliable. At the same time, false triggering is also reduced. When the verification signal does not match the voltage signal, the receiving circuit no longer receives the light signal, thereby avoiding false triggering caused by environmental factors and improving the anti-interference ability of the system. By encoding and verifying the signal, efficient light signal transmission can be achieved in a complex environment to ensure the accuracy and integrity of the information. The verification mechanism enables the system to quickly identify and process valid signals, reduces unnecessary delays, and improves overall communication efficiency. It can effectively prevent the intrusion of external malicious interference signals and ensure the safety and stability of the system. The stability and anti-interference of the through-beam sensor are improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only part of the embodiments of the present invention, rather than all of the embodiments. For ordinary technicians in this field, without paying creative work, other drawings obtained based on these drawings all fall within the scope of protection of this application.

[0046] Figure 1 It is a schematic diagram of the structure of a through-beam photoelectric sensor provided in an embodiment of the present invention.

[0047] Figure 2 is a circuit diagram of a first control module provided in an embodiment of the present invention.

[0048] Figure 3 is a circuit diagram of a transmitting circuit provided by an embodiment of the present invention.

[0049] Figure 4 is a circuit diagram of a second control module provided in an embodiment of the present invention.

[0050] Figure 5 is a circuit diagram of a receiving circuit provided by an embodiment of the present invention.

[0051] Figure 6 is a circuit diagram of a protection circuit provided by an embodiment of the present invention.

[0052] Figure 7 It is a flow chart of an anti-interference method for a through-beam photoelectric sensor provided in an embodiment of the present invention.

[0053] Figure 8It is a comparison table of coding signals, verification signals and voltage signals provided in an embodiment of the present invention.

[0054] Fig. 9 This is a transmission pulse waveform diagram provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0055] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0056] In order to make the description of the disclosed content more detailed and complete, the following is an illustrative description of the implementation mode and specific examples of the present invention; however, this is not the only form of implementing or applying the specific embodiments of the present invention. The implementation mode covers the features of multiple specific embodiments and the method steps and their sequence for constructing and operating these specific embodiments. However, other specific embodiments can also be used to achieve the same or equal functions and step sequences. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0057] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein, for example. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0058] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or units, which can be electrical, mechanical or other forms.

[0059] In the description of the embodiments of the present invention, unless otherwise specified, “ / ” means or, for example, A / B can mean A or B; “and / or” in the text is merely a description of the association relationship of associated objects, indicating that three relationships may exist, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of the present application, “multiple” refers to two or more than two, and other quantifiers are similar. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention, and the embodiments of the present application and the features in the embodiments may be combined with each other without conflict.

[0060] Please refer to Figure 1-Figure 9 The present invention provides a through-beam photoelectric sensor and method, which are used to solve the problems of poor anti-interference ability, complex circuits and many components of the prior art photoelectric sensors.

[0061] For details, please refer to Figure 1 , the present invention provides a through-beam photoelectric sensor, including: a first control module, used to generate a coded signal; a transmitting circuit, connected to the first control module, used to transmit a light signal according to the coded signal; a receiving circuit, used to receive the light signal transmitted by the transmitting circuit and generate a voltage signal; a second control module, connected to the receiving circuit, used to generate a verification signal corresponding to the coded signal; the second control module controls the receiving circuit whether to receive the light signal transmitted by the transmitting circuit according to the matching result of the verification signal and the voltage signal, if the verification signal matches the voltage signal, the second control module controls the receiving circuit to continue to receive the light signal transmitted by the transmitting circuit, if the verification signal does not match the voltage signal, the second control module controls the receiving circuit to stop receiving the light signal transmitted by the transmitting circuit.

[0062] The embodiment provides a beam-type photoelectric sensor that generates a coded signal through a first control module, and a transmitting circuit is connected to the first control module, receives the coded signal and transmits a light signal according to the signal, wherein the light signal is usually transmitted through infrared light, visible light or other wavelength light sources. The receiving circuit receives the light signal emitted by the transmitting circuit and converts it into a voltage signal. The second control module is connected to the receiving circuit, receives the voltage signal from the receiving circuit, and generates a verification signal according to the signal. The coded signal generated by the first control module is transmitted to the transmitting circuit, and the transmitting circuit modulates the light signal according to the received coded signal and transmits it. After receiving the light signal emitted by the transmitting circuit, the receiving circuit converts the light signal into a voltage signal, and the voltage signal is transmitted to the second control module for processing. The second control module compares the verification signal with the voltage signal according to the received voltage signal to see if they match. If the verification signal matches the voltage signal, the second control module confirms that the received light signal is valid and continues to allow the receiving circuit to receive the light signal emitted by the transmitting circuit. If the verification signal does not match the voltage signal, the second control module determines that the received light signal is invalid and controls the receiving circuit to stop receiving the light signal emitted by the transmitting circuit. In this way, signal reliability is improved. By verifying the matching mechanism of the signal and the voltage signal, it is possible to effectively detect and eliminate misjudgments caused by interference, noise or transmission errors, ensuring that the received optical signal is reliable. At the same time, false triggering is also reduced. When the verification signal does not match the voltage signal, the receiving circuit no longer receives the optical signal, avoiding false triggering caused by environmental factors and improving the anti-interference ability of the system. By encoding and verifying the signal, efficient optical signal transmission can be achieved in a complex environment to ensure the accuracy and integrity of the information. The verification mechanism enables the system to quickly identify and process valid signals, reducing unnecessary delays and improving overall communication efficiency. It can effectively prevent the intrusion of external malicious interference signals and ensure the safety and stability of the system. The stability and anti-interference of the said through-beam sensor are improved.

[0063] As a further improvement of the present invention, see Figure 2, the first control module includes: a first processor, a first voltage regulating circuit connected to the twelfth pin of the first processor, a first reset circuit connected to the fourth pin of the first processor, and a first power supply circuit connected to the ninth pin of the first processor. Through the first voltage regulating circuit, it is ensured that the first processor can operate stably under different working conditions, and the output voltage can be adjusted according to actual needs, thereby improving the quality and stability of the coded signal. The first reset circuit can reset the first processor when the system is started, abnormal recovery or reconfigured, ensuring that it starts running from the initial state, enhancing the reliability and stability of the system, and the first power supply circuit provides stable power support for the first processor, ensuring that it can continuously and stably generate coded signals, avoiding work interruptions or abnormalities caused by insufficient power. The various sub-modules work together to ensure that each link in the generation, transmission and reception of coded signals is precisely controlled, improving the performance and efficiency of the overall system. The second pin of the first processor is connected to the transmitting circuit. The first processor is used to send the coded signal to the transmitting circuit. The first processor is responsible for generating the coded signal. It generates a specific coded signal through its internal logic or preset program, and is connected to the transmitting circuit through the second pin to send the coded signal to the transmitting circuit. The second pin is used to communicate with the transmitting circuit to ensure that the coded signal can be accurately transmitted to the transmitting circuit.

[0064] Specifically, the first voltage regulating circuit is connected to the twelfth pin of the first processor, and the voltage regulating circuit is used to regulate the voltage so that the first processor transmits a coded signal corresponding to the voltage. The first voltage regulating circuit is connected to the first processor and is used to regulate the voltage to ensure that the first processor can operate stably under different working conditions, and can adjust the output voltage according to different requirements. Regulating the voltage enables the first processor to transmit a coded signal corresponding to a required voltage level, ensuring signal quality and stability.

[0065] Further, the first reset circuit is used to reset the first processor, and the first reset circuit is connected to the fourth pin of the first processor, so that the first processor starts to run from the initial state; the first power supply circuit, the first power supply circuit is connected to the ninth pin of the first processor, and is used to supply power to the first processor. The reset circuit can ensure that the first processor can return to a stable initial state when the system is started, abnormally recovered or reconfigured, ensure the reliability and stability of the system, and avoid abnormal operation of the first processor due to unexpected circumstances. The first reset circuit is connected to the voltage terminal through the twentieth resistor R20, and is grounded through the eighth capacitor C8. The twentieth resistor R20 and the eighth capacitor C8 constitute a reset circuit. When powered on, the eighth capacitor C8 is charged, and the fourth pin NRST (Non-maskable Reset Pin, reset pin) of the first processor remains at a low level for a period of time, so that the first processor is reset, ensuring that the first processor starts to run from a certain initial state. After charging is completed, the fourth pin NRST of the first processor becomes a high level, and the first processor works normally.

[0066] Specifically, the first power supply circuit is connected to the ninth pin of the first processor to supply power to the first processor. The design of the first power supply circuit ensures that the first processor has sufficient power support under normal working conditions, and ensures that the first processor can continuously and stably generate coded signals. The first power supply circuit is directly connected to the voltage terminal to provide a working voltage for the processor. The ninth capacitor C9, the tenth capacitor C10 and the eleventh capacitor C11 are grounded to achieve filtering, filter out high-frequency and low-frequency noise in the power supply, stabilize the voltage of the first power supply circuit, and ensure the normal operation of the first processor.

[0067] As a further improvement of the present invention, the first voltage regulating circuit includes a potentiometer RT, a first connection end of the potentiometer RT is connected to the voltage end, a second connection end of the potentiometer RT is connected to the twelfth pin of the first processor, and a third connection end of the potentiometer RT is grounded. The first connection end is connected to the voltage end to provide input voltage, the second connection end is connected to the twelfth pin of the first processor to transfer the regulated voltage to the first processor, and the third connection end is grounded to ensure the stability and safety of the circuit. The first processor generates a coded signal of a corresponding voltage according to different voltages. The design of the potentiometer RT makes the voltage regulation more precise, which helps to improve the performance of the first processor in high-precision coded signals.

[0068] As a further improvement of the present invention, see Figure 3, the transmitting circuit includes a first resistor R1, a second resistor R2, a third resistor R3, a first capacitor C1, a first light-emitting diode D1 and a first MOS tube Q1; the voltage end is connected to one end of the first capacitor C1 through the first resistor R1, the other end of the first capacitor C1 is grounded, and the first resistor R1 is connected to the anode of the first light-emitting diode D1; the second resistor R2 connects the gate of the first MOS tube Q1 to the second pin of the first processor, the source of the first MOS tube Q1 is grounded through the third resistor, and the drain of the first MOS tube Q1 is connected to the cathode of the first light-emitting diode D1. The transmitting circuit is powered by the voltage end, the voltage end is connected to one end of the first capacitor C1 through the first resistor R1, and the other end of the first capacitor C1 is grounded. At the same time, the voltage end is connected to the anode of the first light-emitting diode D1, and the second pin of the first processor is connected to the gate of the first MOS tube Q1 through the second resistor R2. The source of the first MOS tube Q1 is grounded through the third resistor R3, and the drain of the first MOS tube Q1 is connected to the cathode of the first light-emitting diode D1. The first resistor R1 plays a current limiting role, limiting the current flowing into the first capacitor C1, and at the same time, together with the first capacitor C1, it forms a filter circuit to filter out the high-frequency noise in the voltage end, so that the voltage at the voltage end is more stable, and provide a stable DC power supply for the subsequent circuit. The first capacitor C1 is used for filtering, storing and releasing charges, smoothing the fluctuation of the power supply voltage, reducing the impact of the power supply noise on the circuit, and ensuring the stable operation of the circuit. The second resistor R2 acts as a current limiting resistor to limit the current flowing into the gate of the first MOS tube Q1 to prevent excessive current from damaging the gate of the first MOS tube Q1. At the same time, it cooperates with the first MOS tube Q1 to drive the first light-emitting diode D1 to emit a corresponding light signal according to the coded signal sent by the second pin of the first processor. The first MOS tube Q1 is used as a switch element in the circuit. When the coding signal is at a high level, the first MOS tube Q1 is turned on, so that the current can form a loop through the first light-emitting diode D1 and the third resistor R3, thereby lighting up the first light-emitting diode D1. When the coding signal sent by the second pin of the first processor is at a low level, the first MOS tube Q1 is turned off, and the first light-emitting diode D1 is extinguished. The control of the first light-emitting diode D1 by the coding signal is realized. The third resistor R3 is a current-limiting resistor of the first light-emitting diode D1, which limits the current passing through the first light-emitting diode D1 to prevent the first light-emitting diode D1 from being damaged by excessive current, and at the same time determines the working current and brightness of the first light-emitting diode D1.

[0069] As a further improvement of the present invention, see Figure 4The second control module includes: a second processor, a second reset circuit connected to the fourth pin of the second processor, and a second power supply circuit connected to the ninth pin of the second processor. The second processor uses a precise control signal to ensure that the receiving circuit can receive the optical signal on demand, thereby improving the signal control accuracy of the system. The second reset circuit can reset the second processor when the system is started, abnormal recovery or reconfigured, ensuring that it starts running from the initial state, thereby enhancing the reliability and stability of the system. The second power supply circuit provides stable power support for the second processor, ensuring that it can continuously and stably generate and process control signals, and avoiding work interruptions or abnormalities caused by insufficient power. The various submodules work together to ensure that each link in the generation, transmission and processing of control signals is accurately controlled, thereby improving the performance and efficiency of the overall system. The third pin of the second processor is connected to the receiving circuit, and the second processor is used to control whether the receiving circuit receives the optical signal emitted by the transmitting circuit; the second processor controls whether the receiving circuit receives the optical signal emitted by the transmitting circuit. The second processor can send a control signal to determine the working state of the receiving circuit by connecting to the receiving circuit through its third pin. The third pin is used to communicate with the receiving circuit to ensure that the control signal can be accurately transmitted to the receiving circuit.

[0070] Specifically, the second reset circuit is connected to the fourth pin of the second processor, and is used to reset the second processor, so that the second processor starts to run from an initial state. The reset circuit can ensure that the second processor can return to a known, stable initial state when the system is started, abnormal recovery or reconfigured, thereby ensuring the reliability and stability of the system and avoiding abnormal operation of the second processor due to unexpected circumstances.

[0071] Furthermore, the second power supply circuit is connected to the ninth pin of the second processor for supplying power to the second processor. The second power supply circuit ensures that the second processor has sufficient power support under normal working conditions. Stable power supply is a prerequisite for the normal operation of the second processor, ensuring that it can continuously and stably generate and process control signals.

[0072] As a further improvement of the present invention, see Figure 5The receiving circuit includes a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a tenth resistor R10, an eleventh resistor R11, a twelfth resistor R12, a thirteenth resistor R13, a fourteenth resistor R14, a second capacitor C2, a third capacitor C3, a fourth capacitor C4, a fifth capacitor C5, a sixth capacitor C6, a seventh capacitor C7, an optocoupler Q2, a first operational amplifier U1 and a second operational amplifier U2, the voltage end is grounded through the fourth resistor R4 and the second capacitor C2, the fourth resistor R4 and the second capacitor C2 are connected in series, the voltage end is grounded through the fourth resistor R4 and the second capacitor C2, and the second capacitor C2 is used to filter out low-frequency noise and provide a stable power supply voltage for the circuit.

[0073] Further, the first pin of the optical coupler Q2 is connected to the fifth resistor R5 through the third capacitor C3, the third capacitor C3 is connected in series with the fifth resistor R5, the other end of the fifth resistor R5 is connected to the in-phase input terminal of the first operational amplifier U1, the first pin of the optical coupler Q2 is grounded through the sixth resistor R6, the first pin of the optical coupler Q2 is grounded through the third capacitor C3 and the seventh resistor R7, the third capacitor C3 is connected in series with the seventh resistor R7, the second pin of the optical coupler Q2 is connected to the voltage terminal through the fourth resistor R4, the second pin of the optical coupler Q2 is grounded through the second capacitor C2, the first pin of the optical coupler Q2 is connected to the fifth resistor R5 through the third capacitor C3, and the other end of the fifth resistor R5 is connected to the in-phase input terminal of the first operational amplifier U1. The second pin of the optical coupler Q2 is connected to the voltage terminal through the fourth resistor R4, and the second pin of the optical coupler Q2 is grounded through the second capacitor C2. The first pin of the optical coupler Q2 is also grounded through the seventh resistor R7 and connected to the voltage terminal through the fourth resistor R4. The fourth resistor R4 is a current limiting resistor, which limits the current through the light-emitting diode inside the optocoupler Q2, prevents the current from being too large to damage the optocoupler Q2, and determines the operating current and luminous intensity of the optocoupler Q2. The optocoupler Q2 converts the input optical signal back to the electrical signal output through the internal photodiode, realizes the electrical isolation between the input circuit and the receiving circuit, avoids the transmission of interference and noise, and also can realize the signal conversion between different levels. The third capacitor C3 is used as a coupling capacitor to cut off the DC signal and only allow the AC signal to pass through, and couples the AC signal output by the optocoupler Q2 to the subsequent amplification circuit to avoid the DC component affecting the static operating point of the amplification circuit. The fifth resistor R5 cooperates with the third capacitor C3 to play the role of impedance matching and signal transmission, and transmits the signal output by the optocoupler Q2 to the in-phase input terminal of the first operational amplifier U1. The seventh resistor R7 and the fourth resistor R4 provide a bias voltage for the output terminal of the optocoupler Q2 to determine the DC operating point of the output signal of the optocoupler Q2.

[0074] Specifically, the inverting input terminal of the first operational amplifier U1 is grounded through the eighth resistor R8 and the fourth capacitor C4, the eighth resistor R8 and the fourth capacitor C4 are connected in series, the inverting input terminal of the first operational amplifier U1 is connected to the output terminal of the first operational amplifier U1 through the fifth capacitor C5 and the ninth resistor R9, the fifth capacitor C5 and the ninth resistor R9 are connected in parallel, the output terminal of the first operational amplifier U1 is connected to the tenth resistor R10 through the sixth capacitor C6, the other end of the tenth resistor R10 is connected to the non-inverting input terminal of the second operational amplifier U2, and the first operational amplifier U2 is connected to the inverting input terminal of the first operational amplifier U1. The power pin of the first operational amplifier U1 is connected to the voltage end, the power pin of the first operational amplifier U1 is grounded through the seventh capacitor C7, and the grounding end of the first operational amplifier U1 is grounded; the voltage end is connected to the power pin of the first operational amplifier U1, the power pin of the first operational amplifier U1 is grounded through the seventh capacitor C7, the seventh capacitor C7 is used to filter out high-frequency noise, and provide a stable power supply voltage for the circuit, the inverting input end of the first operational amplifier U1 is grounded through the eighth resistor R8, and is connected to the output end of the first operational amplifier U1 through the fifth capacitor C5 and the ninth resistor R9, forming a bandpass filter circuit and an amplifier circuit. The output end of the first operational amplifier U1 is connected to the tenth resistor R10 through the sixth capacitor C6, and the other end of the tenth resistor R10 is connected to the in-phase input end of the second operational amplifier U2. The first operational amplifier U1 and the surrounding resistors and capacitors form a bandpass filter and amplifier circuit. The ninth resistor R9, the eighth resistor R8 and the fifth capacitor C5 form a bandpass filter, which is used to filter out unnecessary frequency components in the input signal and only allow signals within a specific frequency range to pass. At the same time, the signal passing through the bandpass filter is amplified.

[0075] Further, the inverting input terminal of the second operational amplifier U2 is connected to the voltage terminal through the eleventh resistor R11, the inverting input terminal of the second operational amplifier U2 is grounded through the twelfth resistor R12, the non-inverting input terminal of the second operational amplifier U2 is connected to the output terminal of the second operational amplifier U2 through the thirteenth resistor R13, the non-inverting input terminal of the second operational amplifier U2 is grounded through the tenth resistor R10 and the fourteenth resistor R14, the tenth resistor R10 and the fourteenth resistor R14 are connected in series, and the output terminal of the second operational amplifier U2 is connected to the third pin of the second processor. The inverting input terminal of the second operational amplifier U2 is connected to the voltage terminal through the eleventh resistor R11, and is grounded through the twelfth resistor R12, and is connected to the output terminal of the second operational amplifier U2 through the thirteenth resistor R13, forming a non-inverting proportional amplifier circuit. The input signal is further amplified, and the amplified signal is finally output.

[0076] As a further improvement of the present invention, see Figure 6The second control module also includes a protection circuit, which includes a fifteenth resistor R15, a sixteenth resistor R16, a seventeenth resistor R17, an eighteenth resistor R18, a first transistor Q3, a second transistor Q4, a first diode D2 and a connector J1; the voltage end is connected to one end of the sixteenth resistor R16, and the other end of the sixteenth resistor R16 is connected to the collector of the second transistor Q4; the tenth pin of the second processor is connected to the base of the second transistor Q4, the emitter of the second transistor Q4 is grounded, and the collector of the second transistor Q4 is connected to the base of the first transistor Q3 through the seventeenth resistor R17; the collector of the first transistor Q3 is connected to the connector J1 through the first diode D2, and the collector of the first transistor Q3 is grounded through the eighteenth resistor R18; the sixteenth pin of the second processor is connected to the base of the first transistor Q3 through the fifteenth resistor R15. The protection circuit is powered by the voltage end. The voltage end is connected to one end of the sixteenth resistor R16, and the other end of the sixteenth resistor R16 is connected to the collector of the second transistor Q4. The collector of the first transistor Q3 is connected to the connector J1 through the first diode D2, and the collector of the first transistor Q3 is grounded through the eighteenth resistor R18. The sixteenth pin of the second processor is connected to the base of the first transistor Q3 through the fifteenth resistor R15. The tenth pin of the second processor is connected to the base of the second transistor Q4, the emitter of the second transistor Q4 is grounded, and the collector of the second transistor Q4 is connected to the base of the first transistor Q3 through the seventeenth resistor R17. The fifteenth resistor R15 acts as a current limiting resistor to limit the current flowing into the base of the first transistor Q3 to prevent the first transistor Q3 from being damaged by excessive current, and at the same time determine the working state of the first transistor Q3, and control the conduction and cutoff of the first transistor Q3 according to the level of the signal of the sixteenth pin of the second processor. The sixteenth resistor R16 provides a collector load resistor for the second transistor Q4. When the second transistor Q4 is turned on or off, the voltage change on the sixteenth resistor R16 affects the state of the subsequent circuit. The seventeenth resistor R17 connects the collector of the second transistor Q4 and the base of the first transistor Q3, plays the role of signal transmission and current limiting, transmits the state of the second transistor Q4 to the first transistor Q3, and limits the current at the same time. The eighteenth resistor R18 serves as the collector load resistor of the first transistor Q3. When the first transistor Q3 is turned on, the current passes through the eighteenth resistor R18 to generate a voltage drop. At the same time, the eighteenth resistor R18 also plays a certain current limiting role to protect the circuit components. The first transistor Q3 controls the output of the circuit according to the sixteenth pin Sensor_Out signal of the second processor and the state of the second transistor Q4.When the signal of the sixteenth pin of the second processor is high and the second transistor Q4 is also turned on, Q1 is turned on, and the voltage end outputs current to the connector J1 through the first transistor Q3 and R18; when the signal of the sixteenth pin Sensor_Out (sensor output) of the second processor is low or Q2 is turned off, the first transistor Q3 is turned off, the output circuit is cut off, and the switch control function is played. The second transistor Q4 is used for short circuit detection and control. When the signal of the tenth pin of the second processor is high, indicating that there may be a short circuit, the second transistor Q4 is turned on, the base of the first transistor Q3 is pulled down, and the first transistor Q3 is cut off, thereby cutting off the output and realizing the short circuit protection function; when the signal of the tenth pin Short_Check (short circuit detection) of the second processor is low, that is, in normal conditions, the second transistor Q4 is cut off, which does not affect the normal operation of the first transistor Q3. The first diode D2 is a transient voltage suppression diode, which is used to protect the circuit from transient voltage spikes. When transient high voltages such as electrostatic discharge and power surge occur in the circuit, the first diode D2 will be quickly turned on to clamp the excessive voltage within a safe range, thereby protecting subsequent circuit components from damage.

[0077] As a further improvement of the present invention, the coded signal is a binary coded signal.

[0078] The present invention also provides an anti-interference method for a through-beam photoelectric sensor, see Figure 7 , the method comprises the following steps:

[0079] Acquire a coded signal, and emit an optical signal according to the coded signal;

[0080] receiving the optical signal and generating a voltage signal;

[0081] generating a check signal corresponding to the coded signal;

[0082] It is determined whether the verification signal matches the voltage signal. If so, the optical signal continues to be received. If not, the optical signal is no longer received.

[0083] When receiving the coded signal, the system first adjusts the voltage corresponding to the coded signal. According to the adjusted voltage, the emission pulse corresponding to the voltage is emitted, so that the optical signal carries the coded information in a specific pulse form. This pulsed emission method improves the anti-interference performance of the said photoelectric sensor. On the one hand, the pulse signal has obvious discreteness in the time domain, which is easier to distinguish from the background noise than the continuous optical signal; on the other hand, the receiving end can use the rising edge, falling edge and other characteristics of the pulse for precise timing synchronization, further improving the accuracy of signal reception. After receiving the optical signal, the receiving circuit converts the optical signal into a voltage signal, and then generates a check signal corresponding to the original coded signal. When judging whether the check signal matches the voltage signal, it actually compares the two bit by bit in the digital domain. If it matches, it means that the optical signal is a correct signal, and the receiving circuit continues to receive the optical signal to ensure the continuity of the data; if it does not match, the optical signal is determined to be an interference signal, and the receiving circuit stops receiving immediately to avoid the accumulation of error information. At the same time, the alarm mechanism can be triggered to prompt the operator to check the interference source or check the transmission line fault.

[0084] As a further improvement of the present invention, before the step of transmitting the optical signal according to the coded signal, the step further includes:

[0085] upon receiving the coded signal, adjusting a voltage corresponding to the coded signal;

[0086] A transmission pulse corresponding to the voltage is transmitted according to the voltage.

[0087] See also Figure 8 The binary code and voltage comparison table provided in this embodiment and Fig. 9 The waveform diagram of the transmitting pulse provided in this embodiment, by specifying the coded signal as a binary coded signal, this improvement brings many significant advantages. In the field of digital communication, binary coding is simple, efficient, easy to implement and correct errors. Compared with complex multi-base coding, binary coding only uses two states of "0" and "1" to represent information, which greatly simplifies the encoding and decoding process. For the transmitting circuit, it becomes more direct to drive the light source according to the binary coded signal, which can reduce the complexity and cost of the circuit design. For example, the emission characteristics of the optical signal, such as pulse width, interval, etc., can be accurately controlled by simple high and low level switching, so that the information carried by the optical signal is easier to be recognized and restored by the receiving circuit. In the process of signal transmission, the error mode generated by the interference of binary coding is relatively single. The common parity check, cyclic redundancy check and other methods can be used to quickly find and correct errors, effectively ensuring the accuracy of the signal, and even in a complex electromagnetic environment, it can ensure that the receiving end obtains reliable optical signal information.

[0088] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0089] The above embodiments only express the preferred implementation modes of the present invention, and the descriptions thereof are relatively specific and detailed, and therefore cannot be understood as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the attached claims.

Claims

1. A through-beam photoelectric sensor, characterized in that: include: A first control module, used to generate a coded signal; a transmitting circuit, connected to the first control module, and configured to transmit an optical signal according to the coded signal; A receiving circuit, used for receiving the optical signal transmitted by the transmitting circuit and generating a voltage signal; a second control module, connected to the receiving circuit, and configured to generate a check signal corresponding to the coded signal; The second control module controls the receiving circuit to receive the optical signal transmitted by the transmitting circuit according to the matching result between the verification signal and the voltage signal. If the verification signal matches the voltage signal, the second control module controls the receiving circuit to continue to receive the optical signal transmitted by the transmitting circuit. If the verification signal does not match the voltage signal, the second control module controls the receiving circuit to stop receiving the optical signal transmitted by the transmitting circuit. The first control module comprises: a first processor, wherein a second pin of the first processor is connected to the transmitting circuit, and the first processor is used to send the coded signal to the transmitting circuit; a first voltage regulating circuit, the voltage regulating circuit being connected to the first processor, and the voltage regulating circuit being used to regulate a voltage so that the first processor transmits a coded signal corresponding to the voltage; The second control module includes: A second processor, a third pin of the second processor is connected to the receiving circuit, and the second processor is used to control whether the receiving circuit receives the optical signal transmitted by the transmitting circuit.

2. The through-beam photoelectric sensor according to claim 1, characterized in that: The first control module also includes: A first reset circuit, used for resetting the first processor so that the first processor starts running from an initial state; A first power supply circuit is connected to a ninth pin of the first processor and is used to supply power to the first processor.

3. The through-beam photoelectric sensor according to claim 2, characterized in that: The first voltage regulating circuit comprises a potentiometer, a first connection end of the potentiometer is connected to a voltage end, a second connection end of the potentiometer is connected to a twelfth pin of the first processor, and a third connection end of the potentiometer is grounded.

4. The through-beam photoelectric sensor according to claim 3, characterized in that: The transmitting circuit includes a first resistor, a second resistor, a third resistor, a first capacitor, a first light emitting diode and a first MOS tube; The voltage terminal is connected to one end of the first capacitor through the first resistor, the other end of the first capacitor is grounded, and the first resistor is connected to the anode of the first light-emitting diode; The second resistor connects the gate of the first MOS tube and the second pin of the first processor, the source of the first MOS tube is grounded through the third resistor, and the drain of the first MOS tube is connected to the cathode of the first light-emitting diode.

5. The through-beam photoelectric sensor according to claim 1, characterized in that: The second control module further includes: A second reset circuit, used for resetting the second processor so that the second processor starts running from an initial state; A second power supply circuit is connected to the fourth pin of the second processor and is used to supply power to the second processor.

6. The through-beam photoelectric sensor according to claim 5, characterized in that: The receiving circuit includes a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor, a thirteenth resistor, a fourteenth resistor, a second capacitor, a third capacitor, a fourth capacitor, a fifth capacitor, a sixth capacitor, a seventh capacitor, an optical coupler, a first operational amplifier, and a second operational amplifier; The voltage terminal is grounded through the fourth resistor and the second capacitor, and the fourth resistor and the second capacitor are connected in series; The first pin of the optocoupler is connected to the fifth resistor through the third capacitor, the third capacitor is connected in series with the fifth resistor, the other end of the fifth resistor is connected to the non-inverting input terminal of the first operational amplifier, the first pin of the optocoupler is grounded through the sixth resistor, the first pin of the optocoupler is grounded through the third capacitor and the seventh resistor, the third capacitor is connected in series with the seventh resistor, the second pin of the optocoupler is connected to the voltage terminal through the fourth resistor, and the second pin of the optocoupler is grounded through the second capacitor; The inverting input terminal of the first operational amplifier is grounded through the eighth resistor and the fourth capacitor, the eighth resistor and the fourth capacitor are connected in series, the inverting input terminal of the first operational amplifier is connected to the output terminal of the first operational amplifier through the fifth capacitor and the ninth resistor, the fifth capacitor and the ninth resistor are connected in parallel, the output terminal of the first operational amplifier is connected to the tenth resistor through the sixth capacitor, the other end of the tenth resistor is connected to the non-inverting input terminal of the second operational amplifier, the power supply pin of the first operational amplifier is connected to the voltage terminal, the power supply pin of the first operational amplifier is grounded through the seventh capacitor, and the ground terminal of the first operational amplifier is grounded; The inverting input terminal of the second operational amplifier is connected to the voltage terminal through the eleventh resistor, the inverting input terminal of the second operational amplifier is grounded through the twelfth resistor, the non-inverting input terminal of the second operational amplifier is connected to the output terminal of the second operational amplifier through the thirteenth resistor, the non-inverting input terminal of the second operational amplifier is grounded through the tenth resistor and the fourteenth resistor, the tenth resistor and the fourteenth resistor are connected in series, and the output terminal of the second operational amplifier is connected to the third pin of the second processor.

7. The through-beam photoelectric sensor according to claim 5, characterized in that: The second control module further includes a protection circuit, and the protection circuit includes a fifteenth resistor, a sixteenth resistor, a seventeenth resistor, an eighteenth resistor, a first transistor, a second transistor, a first diode, and a connector; The voltage end is connected to one end of the sixteenth resistor, and the other end of the sixteenth resistor is connected to the collector of the second transistor; The tenth pin of the second processor is connected to the base of the second transistor, the emitter of the second transistor is grounded, and the collector of the second transistor is connected to the base of the first transistor through the seventeenth resistor; The collector of the first transistor is connected to the connector through the first diode, and the collector of the first transistor is grounded through the eighteenth resistor; The sixteenth pin of the second processor is connected to the base of the first transistor through the fifteenth resistor.

8. The through-beam photoelectric sensor according to claim 1, characterized in that: The coded signal is a binary coded signal.

9. An anti-interference method for a through-beam photoelectric sensor, the method being applied to the through-beam photoelectric sensor according to any one of claims 1 to 8, characterized in that: include: Acquire a coded signal, and emit an optical signal according to the coded signal; receiving the optical signal and generating a voltage signal; generating a check signal corresponding to the coded signal; It is determined whether the verification signal matches the voltage signal. If so, the optical signal continues to be received. If not, the optical signal is no longer received.

10. The anti-interference method of the through-beam photoelectric sensor according to claim 9, characterized in that: Before the step of transmitting the optical signal according to the coded signal, the method further comprises: upon receiving the coded signal, adjusting a voltage corresponding to the coded signal; A transmission pulse corresponding to the voltage is transmitted according to the voltage.

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