Infrared light curtain

Abstract

The utility model discloses an infrared light curtain. The infrared light curtain comprises an infrared transmitting module, an infrared receiving module and a signal processing module, the infrared transmitting module comprises an infrared transmitting tube; the infrared transmitting module is used for transmitting a modulated infrared signal to a set direction; the infrared transmitting tube emits infrared light based on the received control signal; the infrared receiving module and the infrared transmitting module are oppositely arranged, the infrared receiving module comprises an infrared receiving tube and an operational amplifier circuit, and the infrared receiving tube is used for receiving an infrared signal from the infrared transmitting tube and converting a received optical signal into an electric signal; amplifying the received electric signal based on an operational amplification circuit; the signal processing module is connected with the infrared receiving module to receive the electric signal; the signal processing module judges whether an obstacle exists or not based on a preset algorithm, and generates a corresponding control instruction based on an analysis result; the effective detection distance of a single infrared light curtain is improved by adding an operational amplifier circuit to the infrared receiving module.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of rail transit safety technology, in particular to an infrared curtain. BACKGROUND

[0002] Currently, in order to protect the safety of passengers in the rail transit system, a pair of infrared curtains is usually installed on both sides of the shield door for foreign matter detection.

[0003] However, this traditional method requires each shield door to be equipped with a pair of infrared curtains, resulting in high cost and complex installation process. Due to the technical limitations of existing infrared curtains, their effective detection distance is usually not more than 4 meters, which cannot meet the distance requirement of about 10 meters between two doors in a car, so only a pair of infrared curtains can be installed at each door. CONTENT OF THE UTILITY MODEL

[0004] To solve the above problems, the present application discloses an infrared curtain, comprising:

[0005] An infrared emission module, the infrared emission module comprises an infrared emission tube; the infrared emission module is used for emitting modulated infrared signals to a set direction; the infrared emission tube emits infrared light based on the received control signal;

[0006] An infrared receiving module, the infrared receiving module is arranged opposite to the infrared emission module, the infrared receiving module comprises an infrared receiving tube and an operational amplifier circuit, the infrared receiving tube is used for receiving infrared signals from the infrared emission tube and converting the received optical signals into electrical signals; the received electrical signals are amplified based on the operational amplifier circuit;

[0007] A signal processing module, the signal processing module is connected with the infrared receiving module to receive electrical signals; the signal processing module determines whether there is an obstacle based on a preset algorithm and generates corresponding control instructions based on the analysis results.

[0008] Among them, the infrared emission tube and the infrared receiving tube are one-to-one corresponding.

[0009] Among them, the operational amplifier circuit comprises a first operational amplifier, a second operational amplifier, a first resistor, a second resistor, a third resistor, a fourth resistor and a fifth resistor; the negative input end of the first operational amplifier is connected with the positive input end of the electrical signal through the first resistor, the positive input end of the first operational amplifier is connected with the ground end through the second resistor, the output end of the first operational amplifier is connected with the negative input end of the second operational amplifier through the third resistor, the negative input end of the second operational amplifier is connected with the negative input end of the electrical signal through the fourth resistor, and the positive input end of the second operational amplifier is connected with the ground end through the fifth resistor.

[0010] The operation amplifier circuit further includes a sixth resistor, a first capacitor and a second capacitor; one end of the sixth resistor is connected to the negative input end of the first operational amplifier close to one side of the first resistor, and the other end of the sixth resistor is connected to the output end of the first operational amplifier close to one side of the third resistor; one end of the first capacitor is connected to the fourth terminal of the first operational amplifier, the other end of the first capacitor is connected to one end of the second capacitor, and the other end of the second capacitor is connected to the output end of the first operational amplifier close to one side of the third resistor; the other end of the first capacitor and one end of the second capacitor are connected to one side of the sixth resistor close to the negative input end of the first operational amplifier.

[0011] The operation amplifier circuit further includes a seventh resistor and a third capacitor; the seventh resistor and the third capacitor are connected in parallel to the negative input end and the output end of the second operational amplifier.

[0012] The infrared transmitting tube and the infrared receiving tube are respectively provided with protective covers, and the accuracy of infrared light transmission is improved based on the protective covers.

[0013] The temperature compensation circuit is further included, which is connected to the operation amplifier circuit and used for correcting signal drift caused by temperature change.

[0014] The signal processing module includes a filter unit for removing background noise and interference signals.

[0015] The infrared transmitting tube adopts a high-power infrared LED to increase signal strength and transmission distance.

[0016] The signal processing module further includes a communication interface, based on which data exchange with an external control system is performed to realize remote monitoring and management.

[0017] Compared with the prior art, the application has the following at least one beneficial effect:

[0018] 1. The effective detection distance of a single infrared light curtain is increased by adding an operation amplifier circuit to the infrared receiving module.

[0019] 2. The infrared transmitting module and the infrared receiving module are equipped with protective covers, so that they can normally operate in harsh working environments and prolong the service life of the equipment.

[0020] 3. The one-to-one correspondence between the infrared transmitting tube and the infrared receiving tube improves the accuracy of infrared signal transmission.

[0021] 4. The temperature compensation circuit corrects signal drift caused by temperature change to ensure the stability and reliability of the system under different temperature conditions. BRIEF DESCRIPTION OF DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments description will be briefly introduced. Obviously, the drawings in the following description only constitute some embodiments of the present application, and for those skilled in the art, other drawings can be obtained without creative effort based on these drawings.

[0023] Wherein:

[0024] Figure 1 The frame schematic diagram of an embodiment of the infrared light curtain provided by the present application is shown in the figure.

[0025] Figure 2 The structure schematic diagram of an embodiment of the operational amplifier circuit provided by the present application is shown in the figure. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the present application will be described clearly and completely in the following with reference to the drawings in the embodiments of the present application. It can be understood that the specific embodiments described herein are only used to explain the present application, but not to limit the present application. In addition, it should be noted that, for the convenience of description, only the parts related to the present application are shown in the drawings, but not all the structures. Based on the embodiments in the present application, all the other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present application.

[0027] The terms "first", "second", and the like in the present application are used to distinguish different objects, but not to describe a specific order. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device including a series of steps or units is not limited to the listed steps or units, but optionally includes other steps or units not listed or optionally includes other steps or units inherent to the process, method, product or device.

[0028] In this document, the term "embodiment" means that the specific features, structures or characteristics described in connection with the embodiment can be included in at least one embodiment of the present application. The phrase appears in various places in the specification does not necessarily refer to the same embodiment, nor is it mutually exclusive or alternative to other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0029] The infrared curtain is widely used in industrial automation, security monitoring and other fields for detecting the presence of objects or obstacles. The existing infrared curtain system has certain limitations in signal processing, anti-interference ability and temperature compensation, resulting in insufficient detection accuracy and stability. Therefore, there is an urgent need for an infrared curtain system that can improve detection accuracy, enhance anti-interference ability and have temperature compensation function. In this regard, the present application provides an infrared curtain as shown in Figure 1 Figure 1 The framework diagram of an embodiment of the infrared curtain provided by the present application includes an infrared emitting module, an infrared receiving module and a signal processing module.

[0030] The infrared emitting module includes an infrared emitting tube; the infrared emitting module is used to emit modulated infrared signals to a set direction; the set direction is determined by the positions of the infrared emitting module and the infrared receiving module, and no limitation is made in this regard, for example, the set direction is the horizontal direction.

[0031] The infrared emitting tube emits infrared light based on the received control signal; that is, after the infrared emitting tube receives the control signal, it emits modulated infrared light based on the instructions of the control signal. The modulation method includes but is not limited to pulse width modulation and frequency modulation, which enhances the anti-interference ability and ensures that the signal can be transmitted over a long distance without distortion.

[0032] The infrared emitting module improves the anti-interference ability and detection distance of the system by using modulation technology and directional emission strategy, at the same time simplifies the installation and maintenance process, enhances the overall reliability and flexibility of the system.

[0033] The infrared receiving module is arranged opposite to the infrared emitting module, and the infrared receiving module includes an infrared receiving tube and an operational amplifier circuit, the infrared receiving tube is used to receive infrared signals from the infrared emitting tube and convert the received optical signals into electrical signals; the received electrical signals are amplified based on the operational amplifier circuit.

[0034] The infrared receiving module is arranged opposite to the infrared emitting module, and contains a plurality of infrared receiving tubes. These receiving tubes are arranged on the other side of the shielding door, corresponding to the infrared emitting tubes one by one. When there is no obstacle, the modulated infrared light emitted by the infrared emitting tube can reach the corresponding infrared receiving tube smoothly; the weak electrical signals received are amplified by the operational amplifier circuit, which can ensure sufficient signal strength even in the case of long distance transmission, improving the detection sensitivity of the system.

[0035] The signal processing module is connected to the infrared receiving module to receive electrical signals; the signal processing module determines whether there is an obstacle based on a preset algorithm, common algorithms include but are not limited to:

[0036] ​Threshold detection: Set a threshold. If the signal strength is lower than the threshold, it is considered that there is an obstacle blocking the infrared light.

[0037] Pattern recognition: Using machine learning models to identify changes in specific patterns, such as a simultaneous decrease in signal strength at multiple receiving points, indicating that a large object is obstructing the signal.

[0038] Time series analysis: Monitor the trend of signal changes over time and identify abnormal fluctuations as indicators of the presence of obstacles.

[0039] Based on the analysis results, corresponding control commands are generated. If an obstacle is detected, the signal processing module will generate corresponding control commands. These commands may include, but are not limited to: triggering a relay to disconnect to prevent the platform screen door from closing and sending an alarm to the operator or control system to notify of the presence of an obstacle.

[0040] In summary, the infrared light curtain of this application includes an infrared emitting module, an infrared receiving module, and a signal processing module. The infrared emitting module includes an infrared emitting tube. The infrared emitting module is used to emit modulated infrared signals to a set direction. The infrared emitting tube emits infrared light based on the received control signal. The infrared receiving module is arranged opposite to the infrared emitting module. The infrared receiving module includes an infrared receiving tube and an operational amplifier circuit. The infrared receiving tube is used to receive the infrared signal from the infrared emitting tube and convert the received light signal into an electrical signal. The operational amplifier circuit amplifies the received electrical signal. The signal processing module is connected to the infrared receiving module to receive the electrical signal. The signal processing module determines whether there is an obstacle based on a preset algorithm and generates corresponding control commands based on the analysis results. The effective detection distance of a single infrared light curtain is improved by adding an operational amplifier circuit to the infrared receiving module.

[0041] Optionally, the infrared emitting tubes and infrared receiving tubes are in one-to-one correspondence; each pair of infrared emitting tubes and infrared receiving tubes are in one-to-one correspondence, and the angle of each emitting tube and receiving tube is adjusted to ensure that the emitted infrared light can accurately enter the corresponding receiving tube, avoiding signal loss caused by offset or misalignment.

[0042] By achieving precise one-to-one alignment, the system ensures that the light emitted by each infrared emitter reaches its corresponding infrared receiver accurately, reducing misjudgments or missed detections caused by light deviation and improving the system's detection accuracy. The one-to-one design significantly reduces interference between adjacent channels, as each receiver only receives signals from a specific emitter, thereby enhancing the system's anti-interference capability.

[0043] like Figure 2 As shown, Figure 2 This is a schematic diagram of an embodiment of the operational amplifier circuit provided in this application.

[0044] The operational amplifier circuit comprises a first operational amplifier U1, a second operational amplifier U2, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, and a fifth resistor R5; the negative input end of the first operational amplifier U1 is connected to the positive input end of the electric signal through the first resistor R1, the positive input end of the first operational amplifier U1 is connected to the ground through the second resistor R2, the output end of the first operational amplifier U1 is connected to the negative input end of the second operational amplifier U2 through the third resistor R3, the negative input end of the second operational amplifier U2 is connected to the negative input end of the electric signal through the fourth resistor R4, and the positive input end of the second operational amplifier U2 is connected to the ground through the fifth resistor R5.

[0045] The operational amplifier circuit further comprises a sixth resistor R6, a first capacitor C1, and a second capacitor C2; one end of the sixth resistor R6 is connected to the negative input end of the first operational amplifier U1 close to one side of the first resistor R1, and the other end of the sixth resistor R6 is connected to the output end of the first operational amplifier U1 close to one side of the third resistor R3; one end of the first capacitor C1 is connected to the fourth end of the first operational amplifier U1, the other end of the first capacitor C1 is connected to one end of the second capacitor C2, and the other end of the second capacitor C2 is connected to the output end of the first operational amplifier U1 close to one side of the third resistor R3; the other end of the first capacitor C1 and one end of the second capacitor C2 are connected to one side of the sixth resistor R6 close to the negative input end of the first operational amplifier U1.

[0046] The operational amplifier circuit further comprises a seventh resistor R7 and a third capacitor C3; the seventh resistor R7 and the third capacitor C3 are connected in parallel to the negative input end and the output end of the second operational amplifier U2.

[0047] The working principle of the operational amplifier circuit of the embodiment will be described in detail below:

[0048] After the electric signal is received from the infrared receiving tube, it is connected to the negative input end of the first operational amplifier U1 through the first resistor R1. The positive input end is grounded through the second resistor R2, forming an inverting amplifier configuration.

[0049] The sixth resistor R6 is connected in parallel between the negative input end and the output end of U1, providing local feedback to stabilize the gain and reduce the influence of temperature drift. The third resistor R3 connects the output of the first operational amplifier U1 to the negative input end of the second operational amplifier U2, further transmitting the amplified signal.

[0050] The first capacitor C1 and the second capacitor C2 are used for filtering and smoothing the signal. One end of the first capacitor C1 is connected to the compensation end of the first operational amplifier U1, i.e., the fourth end of the first operational amplifier, the other end of the first capacitor C1 is connected to one end of the second capacitor C2, and the other end of the second capacitor C2 is connected to the output end of the first operational amplifier U1 close to one side of the third resistor R3. At the same time, the common point of the first capacitor C1 and the second capacitor C2 is also connected to one side of the sixth resistor R6 close to the negative input end of the first operational amplifier U1, to remove high-frequency noise and unnecessary interference.

[0051] The negative input terminal of the second operational amplifier U2 is connected to the negative input terminal of the electrical signal through the fourth resistor R4, and is connected to its own output terminal through the parallel connection of the seventh resistor R7 and the third capacitor (C3), which not only increases the overall gain, but also improves the stability of the system and avoids the possibility of self-oscillation.

[0052] The positive input terminal of the second operational amplifier U2 is grounded through the fifth resistor R5, ensuring the stability of the reference voltage.

[0053] Optionally, the infrared emitting tube and the infrared receiving tube are respectively provided with protective covers, and the accuracy of infrared light transmission is improved based on the protective covers; the protective covers do not cause refraction, reflection or scattering of infrared light, maintaining the accuracy of the light transmission path; the protective covers should have functions such as dustproof, waterproof and impact resistance to adapt to different working environments.

[0054] The protective covers can prevent dust, water vapor and other pollutants from directly contacting the infrared emitting tube and the receiving tube, avoiding signal attenuation or distortion caused by pollution, thereby improving the accuracy and stability of infrared light transmission; through dustproof and waterproof design, the protective covers can protect the infrared emitting tube and the receiving tube in harsh environments, prolong the service life, reduce the failure rate, and enhance the overall reliability of the system.

[0055] Optionally, the infrared light curtain further comprises a temperature compensation circuit connected to the operational amplifier circuit for correcting signal drift caused by temperature changes; the temperature compensation circuit includes a microcontroller or an application-specific integrated circuit (ASIC) for executing a temperature compensation algorithm. The algorithm calculates the required compensation value at the current temperature based on a pre-calibrated data table or mathematical model.

[0056] Based on the real-time temperature data provided by the temperature sensor, the corresponding compensation value is calculated and applied to the gain control or bias voltage adjustment of the operational amplifier circuit; the compensation value is converted into an analog signal through a digital-to-analog converter and then fed back to the operational amplifier circuit. Specifically, temperature compensation can be achieved by adjusting the bias voltage or gain resistance of the first operational amplifier U1 or the second operational amplifier U2. For example, by dynamically adjusting the resistance values of the sixth resistor R6 and / or the seventh resistor R7 through a variable resistor or a digital potentiometer, the gain of the feedback network is changed to offset the effects of temperature changes.

[0057] The temperature compensation circuit can monitor and correct signal drift caused by temperature changes in real time, ensuring that the output signal remains consistent under different temperature conditions and improving the stability and reliability of the system; through accurate temperature compensation, the effects of temperature changes on the performance of the infrared emitting tube and the receiving tube are avoided, making the detection results more accurate and reliable, and reducing the probability of false positives and missed detections.

[0058] Optionally, the signal processing module comprises a filter unit for removing background noise and interference signals; the filter unit can select any of the following filters, without any limitation;

[0059] Low-pass filter: allows signals below a certain cutoff frequency to pass, removing high-frequency noise.

[0060] High-pass filter: allows signals above a certain cutoff frequency to pass, removing low-frequency drift.

[0061] Band-pass filter: only allows signals within a certain frequency range to pass, while removing low and high frequency interference.

[0062] Optionally, the infrared emitter tube uses high-power infrared LEDs to increase signal strength and transmission distance; high-power infrared LEDs can provide stronger light output, and stronger signal strength helps to improve the signal quality received by the receiving end, even at long distances, while maintaining a high signal-to-noise ratio; strong signals have better penetration ability during transmission, and can more effectively penetrate small particles such as dust and water vapor in the air, reducing signal attenuation caused by environmental factors.

[0063] Optionally, the signal processing module further comprises a communication interface for data exchange with an external control system, enabling remote monitoring and management; real-time data transmission is achieved through the communication interface, and the external control system can obtain the running state and detection results of the infrared light curtain system in real time. Once an abnormal situation is found (e.g., the presence of an obstacle), measures can be taken quickly, such as triggering an alarm, stopping the shutter from closing, etc., improving the response speed and safety of the system.

[0064] The communication interface enables the signal processing module to seamlessly integrate with other intelligent devices or systems, building more complex automation solutions. For example, it can be linked with a video monitoring system to automatically retrieve video footage of the relevant area when an obstacle is detected, providing more comprehensive security.

[0065] In several embodiments provided in the present application, it should be understood that the disclosed methods and devices can be implemented in other ways. For example, the device embodiments described above are only illustrative, such as the division of the modules or units, which is only a logical functional division, and actual implementation can have another division method, such as combining or integrating into another system, or some features can be ignored or not executed.

[0066] The units described as separate components may or may not be physically separate, and the components displayed as units may or may not be physical units, that is, may be located in one place, or may be distributed to multiple network units. Part or all of the units can be selected according to actual needs to achieve the purpose of the present embodiment scheme.

[0067] In addition, each functional unit in each embodiment of the present application can be integrated into one processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit. The integrated unit can be realized in the form of hardware or in the form of a software functional unit.

[0068] The above is only an embodiment of the present application, and does not limit the patent scope of the present application, and any equivalent structure or equivalent flow transformation using the content of the present application specification and drawings, or direct or indirect application in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. An infrared light curtain, characterized in that, The application relates to an infrared obstacle avoidance system. The infrared emission module comprises an infrared emission tube; the infrared emission module is used for emitting modulated infrared signals to a set direction; the infrared emission tube emits infrared light based on a received control signal; The infrared receiving module is oppositely arranged with the infrared emission module; the infrared receiving module comprises an infrared receiving tube and an operational amplifier circuit; the infrared receiving tube is used for receiving infrared signals from the infrared emission tube and converting the received optical signals into electrical signals; the received electrical signals are amplified based on the operational amplifier circuit; The signal processing module is connected with the infrared receiving module to receive the electrical signals; The signal processing module judges whether there is an obstacle based on a preset algorithm and generates corresponding control instructions based on the analysis result.

2. The infrared light curtain of claim 1, wherein, The infrared emission tube and the infrared receiving tube correspond to each other.

3. The infrared light curtain of claim 2, wherein, The operational amplifier circuit comprises a first operational amplifier, a second operational amplifier, a first resistor, a second resistor, a third resistor, a fourth resistor and a fifth resistor; the negative input end of the first operational amplifier is connected with the positive input end of the electrical signal through the first resistor; the positive input end of the first operational amplifier is connected with the ground end through the second resistor; the output end of the first operational amplifier is connected with the negative input end of the second operational amplifier through the third resistor; the negative input end of the second operational amplifier is connected with the negative input end of the electrical signal through the fourth resistor; and the positive input end of the second operational amplifier is connected with the ground end through the fifth resistor.

4. The infrared light curtain of claim 3, wherein, The operational amplifier circuit further comprises a sixth resistor, a first capacitor and a second capacitor; one end of the sixth resistor is connected with the negative input end of the first operational amplifier close to one side of the first resistor; and the other end of the sixth resistor is connected with the output end of the first operational amplifier close to one side of the third resistor; One end of the first capacitor is connected with the fourth end of the first operational amplifier; the other end of the first capacitor is connected with one end of the second capacitor; and the other end of the second capacitor is connected with the output end of the first operational amplifier close to one side of the third resistor; The other end of the first capacitor and one end of the second capacitor are connected with one side of the sixth resistor close to the negative input end of the first operational amplifier.

5. The infrared light curtain of claim 4, wherein, The operational amplifier circuit further comprises a seventh resistor and a third capacitor; the seventh resistor and the third capacitor are connected in parallel to the negative input end and the output end of the second operational amplifier.

6. The infrared light curtain of claim 5, wherein, The infrared emission tube and the infrared receiving tube are respectively provided with protective covers to improve the accuracy of infrared light transmission.

7. The infrared light curtain of claim 6, wherein, The application further comprises a temperature compensation circuit connected with the operational amplifier circuit and used for correcting signal drift caused by temperature change.

8. The infrared light curtain of claim 7, wherein, The signal processing module comprises a filter unit used for removing background noise and interference signals.

9. The infrared light curtain of claim 8, wherein, The infrared emission tube adopts a high-power infrared LED to increase signal strength and transmission distance.

10. The infrared light curtain according to any one of claims 1-9, wherein, The signal processing module further comprises a communication interface used for data exchange with an external control system to realize remote monitoring and management.

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