A safety interlocking system for infrared laser long-distance wireless charging

Abstract

The present application relates to the technical field of wireless charging, and particularly relates to a safety interlocking system for infrared laser long-distance wireless charging; through cooperation of spatial distribution of multiple photodiodes and hardware structure, when the light path is invaded by foreign matters, the control circuit can quickly cut off the high-power laser output, and the three-dimensional layout eliminates the spatial blind area of single-point detection, the polarization discrimination element in the transmitting end device and the phase delay element in the receiving end device are combined to construct an optical encryption closed loop, only the light received by the sensor after being inversely reflected to the receiving end rotatable polarization state is allowed, the in-phase polarized light reflected by ordinary mirror foreign matters is effectively blocked, the risk of mirror deception reflection attack in the high-power scene is greatly reduced, and through the pure hardware phase-locked loop frequency decoding circuit, only the reflected light output logic level carrying the preset modulation frequency is output, direct current and low-frequency interference of sunlight and illumination light sources are filtered from the physical layer.

Description

Technical Field

[0001] This invention relates to the field of wireless charging technology, and in particular to a safety interlocking system for long-distance wireless charging using infrared laser. Background Technology

[0002] Infrared lasers, due to their high atmospheric transmittance, good directionality, and compatibility with high-efficiency photovoltaic cells, have become an ideal carrier for long-distance (e.g., several meters to tens of meters) wireless power transmission, and are widely used in drones, IoT nodes, mobile robots, and consumer electronics for long-distance power supply. However, high-power infrared lasers (usually Class IV laser products) that meet charging requirements pose certain safety hazards during use due to the lack of a proper protection system. Specifically: High-power infrared lasers are invisible to the human eye and have concentrated energy. If the beam path is accidentally blocked by a human body or flammable material, it may cause serious eye damage, skin burns, or fires within milliseconds. When the power is increased to the tens of watts level, specular reflective objects (such as glass or metal sheets) cutting into the light path may reflect the laser in an unexpected direction, causing even more serious secondary injuries. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this invention provides a safety interlocking system for long-distance wireless charging of infrared lasers. This system solves the technical problem that existing infrared lasers, due to the lack of a protection system, may damage objects in their path during long-distance wireless energy transmission, and may cause secondary damage to other objects when reflected.

[0004] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a safety interlocking system for infrared laser long-distance wireless charging, comprising a transmitter device, a receiver device, and a control circuit; The transmitting device includes a laser emitting module for outputting an infrared energy-transmitting laser beam, a reflected light detection module for receiving reflected light from the infrared energy-transmitting laser beam, and an anti-interference module for filtering out light interference. The infrared energy-transmitting laser beam has a pulse modulation signal of a preset frequency and a preset first polarization direction. The reflected light detection module includes multiple photodiodes distributed around a preset center point, used to convert optical signals into photocurrents; The anti-interference module is used to filter out light rays with only the second polarization direction that are incident on the photodiode, and then convert the photocurrent component output by the photodiode with the same frequency as the pulse modulation signal into a DC logic level. The receiving device includes a photoelectric conversion module for receiving an infrared energy-transmitting laser beam and converting it into electrical energy, and at least one retroreflector disposed around the photoelectric conversion module for converting the first polarization direction of a portion of the incident infrared energy-transmitting laser beam into a second polarization direction and reflecting it back to the transmitting device along the original path. The control circuit is used to maintain the output of the infrared energy transmission laser beam of the transmitting device when the anti-interference modules corresponding to multiple photodiodes all output DC logic levels; otherwise, it cuts off the output of the infrared energy transmission laser beam of the transmitting device.

[0005] Preferably, the anti-interference module includes a polarization discrimination element disposed on the light-incident surface of the photodiode, the transmission axis of which is consistent with the second polarization direction, and a filter module electrically connected to the output terminal of the photodiode, for converting the photocurrent component with the same frequency as the pulse modulation signal in the photocurrent output by the photodiode into a DC logic level.

[0006] Preferably, the incident surface of the retroreflector is provided with a phase delay element, which, in conjunction with the retroreflector, rotates the infrared energy-transmitting laser beam from the first polarization direction to the second polarization direction.

[0007] Preferably, the control circuit further includes a start-up trigger module, which is used to send a bypass start signal to the enable control terminal after the system initially establishes a connection or the link is interrupted.

[0008] Preferably, the laser emitting module includes a high-power energy transfer mode and a low-power pathfinding mode. When the system initially establishes a connection or restarts after a link interruption, the control circuit controls the laser emitting module to switch to the low-power pathfinding mode to output an infrared energy transfer laser beam with power conforming to a preset standard and frequency of a preset frequency. When the anti-interference module corresponding to each photodiode outputs a DC logic level, the control circuit controls the laser emitting module to switch to the high-power energy transfer mode to output an infrared energy transfer laser beam that meets the charging requirements.

[0009] Preferably, the wavelength of the infrared energy-transmitting laser beam is 800nm ​​to 1100nm, and the retroreflector is a solid corner cone prism or a hollow retroreflector array 22.

[0010] Preferably, the first polarization direction is orthogonal to the second polarization direction.

[0011] By employing the above technical solution, the present invention provides a safety interlocking system for long-distance wireless charging with infrared laser, which has at least the following beneficial effects: 1. This invention, through the spatial distribution of multiple photodiodes and the coordination of hardware structure, enables the control circuit to unconditionally cut off the high-power laser output within microseconds when the optical path is invaded by foreign objects. The response speed far exceeds that of mechanical shutters and software algorithms. Moreover, the three-dimensional layout eliminates the spatial blind spots of single-point detection, achieving all-round intrinsic safety protection for the beam path.

[0012] 2. This invention constructs an optical encryption closed loop by combining the polarization discrimination element in the transmitting device with the phase delay element in the receiving device. Only light whose polarization state has been rotated by the retroreflector at the receiving end is allowed to be received by the sensor. In-phase polarized light reflected by ordinary mirror foreign objects is effectively blocked, which greatly reduces the risk of mirror deception reflection attacks in high-power scenarios.

[0013] 3. This invention uses a pure hardware phase-locked loop frequency decoding circuit to output logic levels only to reflected light carrying a preset modulation frequency, thereby physically filtering out DC and low-frequency interference from sunlight and lighting sources, ensuring zero false triggering under complex outdoor lighting conditions, and automatically restoring high-power transmission after the obstruction is removed. Attached Figure Description

[0014] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings: Figure 1 This is a schematic diagram of the safety interlocking system for infrared laser long-distance wireless charging of the present invention. Figure 2 This is a schematic diagram of the safety interlocking system for infrared laser long-distance wireless charging according to the present invention. Figure 3 This is a schematic diagram of the arrangement of the photodiodes in this invention; Figure 4 This is a circuit diagram of the safety interlocking system of the present invention; Figure 5 This is a schematic diagram of the laser path of the present invention; Figure 6 This is a schematic diagram of the laser path during foreign object intrusion according to the present invention.

[0015] In the diagram: 1. Transmitter; 11. Laser emission module; 12. Reflected light detection module; 2. Receiver; 21. Photoelectric conversion module; 22. Retroreflector. Detailed Implementation

[0016] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. This will allow for a full understanding of how the present application uses technical means to solve technical problems and achieve technical effects, and to facilitate its implementation.

[0017] To address the technical problem that existing infrared lasers, lacking a protection system, may damage objects along their path during long-distance wireless energy transmission, and may cause secondary damage to other objects upon reflection, this invention provides a safety interlocking system for long-distance wireless charging of infrared lasers, such as... Figure 1 As shown, it consists of three parts: transmitter device 1, receiver device 2, and control circuit. The following is a detailed description of each part: First, the transmitting device 1 integrates a laser emitting module 11 for outputting an infrared energy-transmitting laser beam, a reflected light detection module 12 for receiving reflected light from the infrared energy-transmitting laser beam, and an anti-interference module for filtering out light interference. In this embodiment, the laser emitting module 11 outputs an infrared energy-transmitting laser beam. The wavelength of this laser beam is preferably in the 800nm ​​to 1100nm band, which has high atmospheric transmittance, and the power is between 1 and 50W to meet the requirements of long-distance wireless charging. It has an enable control terminal (TTL interface). Furthermore, to ensure controllable beam spread during long-distance transmission, a collimating optical system is also provided on the laser emitting module 11 to control the laser beam emission angle, ensuring that the emission angle is less than 2mrad. The laser emitting module 11 also has a high-frequency modulation function, enabling the output laser beam to carry a pulse modulation signal of a specific frequency (e.g., 100kHz), and the emitted laser beam is linearly polarized light (e.g., vertically polarized light) with a preset first polarization direction. Specifically, for example... Figure 2 As shown, the driving circuit of the laser emitting module 11 is equipped with a modulation signal generator, so that the output laser beam carries a pulse modulation signal with a preset frequency.

[0018] To further ensure the safety of the laser beam during use, the laser emitting module 11 is equipped with a dual-power drive circuit belonging to the control circuit, enabling the laser emitting module 11 to have two operating modes: high-power energy transfer mode and low-power pathfinding mode. In high-power energy transfer mode and low-power pathfinding mode, the laser emitting module 11 can emit laser beams with preset frequencies and different frequency values ​​respectively. In low-power pathfinding mode, the laser emitting module 11 outputs a frequency-modulated probe laser beam, and the modulation frequency is a preset characteristic frequency (preferably a single frequency or pulse code sequence in the range of 1kHz-100kHz). In high-power energy transfer mode, its output power meets the charging requirements of the downstream load (e.g., 1W to 50W); in low-power pathfinding mode, its output power is limited to a preset safety standard (e.g., less than 0.5mW in accordance with Class 1 laser safety standards). This mode is used to detect whether the optical path is restored to unobstructed status when the system initially establishes a connection or restarts after a link interruption, avoiding damage to objects on the optical path. When the anti-interference module corresponding to each photodiode in the reflected light detection module 12 outputs a DC logic level, the laser emission module 11 is controlled to switch to high-power energy transfer mode to output an infrared energy transfer laser beam that meets the charging requirements. Specifically, in this embodiment, as shown... Figure 4 As shown, single-pole double-throw switch The common terminal (COM) of the preferred model FSA4159P6X in this embodiment is connected to the laser driver circuit. The two selection terminals are connected to two different voltage divider setting networks, namely the low-power pathfinding mode setting network and the high-power energy transfer mode setting network: Low-power pathfinding mode setting network: composed of resistors Composition. When When switched to this path, the laser drive circuit obtains a set voltage corresponding to low power (compliant with Class 1 standards, less than 0.5mW), enabling the laser emission module to output a safe probe laser.

[0019] High-power energy transfer mode setting network: consisting of an adjustable potentiometer constitute. sliding end connection The second optional terminal (normally open, NO). When When switched to this path, the laser drive circuit obtains the set voltage corresponding to full-power energy transfer (1-50W) and adjusts... The output power of the energy-transmitting laser can be precisely set.

[0020] Control logic: The control terminal (SEL pin) is connected to the output terminal of the frequency identification circuit (i.e. Figure 4 Inverter The output terminal of the frequency identification circuit. When the frequency identification circuit detects a valid reflected light signal (i.e., satisfies polarization matching and frequency matching), it outputs a high level, driving the circuit. Switch to The current path (i.e., high-power mode) outputs a low level when the reflected light signal is lost or abnormal. Automatic reset to resistor The current path (i.e., low power mode) enables a purely hardware-based closed-loop self-sustaining safety interlock and automatic recovery.

[0021] like Figure 3 As shown, the reflected light detection module 12 includes multiple photodiodes distributed around a preset center point, used to convert light signals into photocurrents. In this embodiment, a detection substrate is provided on the transmitting device 1 as a fixed carrier, and then multiple photodiodes are installed on it. The number of photodiodes is greater than or equal to 2, for example, 4 are installed. Then, the multiple photodiodes are distributed around the preset center point, for example, arranged in an orthogonal cross around the preset center point in an upward, downward, left and right manner, or arranged in a ring with equal intervals and included angles around the preset center point.

[0022] The anti-interference module is a core component for achieving safety interlocking. It is used to filter light rays with only a second polarization direction from entering the photodiode. In this embodiment, this is achieved by a polarization discrimination element disposed on the light-incident surface of the photodiode. The polarization discrimination element is preferably a polarizer orthogonal to the polarization direction of the laser beam emitted by the laser emitting module 11, such as a horizontal polarizer. This element is used to block in-phase polarized light directly reflected by ordinary mirrors or metallic foreign objects, eliminating high-risk reflection deception. Then, the photocurrent component output by the photodiode, which has the same frequency as the pulse modulation signal, is converted into a DC logic level. In this embodiment, this function is achieved by a filter module electrically connected to the output terminal of the photodiode. This filter module is a pure hardware bandpass filter circuit or a phase-locked loop frequency decoding chip, such as the LM567 decoding chip. The center frequency of the filter circuit or decoding chip is consistent with the modulation frequency of the laser emitting module 11. This module is used to filter out low-frequency interference from DC background light such as sunlight and indoor lighting, converting the AC photocurrent of a specific frequency into a DC logic level. This mechanism ensures that the system only responds to the laser beam reflected from the retroreflector 22, resisting ambient light interference and diffuse reflection false triggering.

[0023] Secondly, the receiving device 2 includes a photoelectric conversion module 21 for receiving the infrared energy-transmitting laser beam and converting it into electrical energy. In this embodiment, a GaAs laser cell or VMJ silicon-based multi-junction cell optimized for the 800nm-1100nm band is preferred. At least one retroreflector 22 is also arranged around the photoelectric conversion module 21 to convert the first polarization direction of part of the incident infrared energy-transmitting laser beam into the second polarization direction and reflect it back to the transmitting device 1 along the original path. In this embodiment, the retroreflector 22 is preferably a solid corner bevel prism or a hollow retroreflector 22 array, which has a reflectivity of more than 90% for the 800nm-1100nm band laser beam, which can ensure sufficient signal under various harsh conditions (such as long distance, severe weather or air pollution). In this embodiment, a phase delay element, preferably a quarter-wave plate, is provided at the light-incident surface of the retroreflector 22. It works in conjunction with the retroreflector 22 to rotate the infrared energy-transmitting laser beam from the first polarization direction to the second polarization direction. When the linearly polarized laser output from the transmitting device 1 passes through the quarter-wave plate twice and is reflected by the retroreflector 22, its polarization direction is rotated by 90 degrees (e.g., from vertical polarization to horizontal polarization). This allows it to penetrate the first polarization element on the surface of the transmitting photodiode and be successfully received, forming an "optical key" mechanism.

[0024] Finally, the output of the reflected light detection module 12, after being shaped by a comparator, is connected to the enable control terminal of the laser emission module 11 via a pure hardware serial network or a hardware AND gate logic. The serial link is only activated when all reflected light detection modules 12 simultaneously detect reflected light with matching polarization direction and modulation frequency, and the laser emission module 11 maintains light output. When any reflected light detection module 12 fails to detect reflected light, or when the foreign object is a common mirror (polarization error), or when it is exposed to strong sunlight (frequency error), the serial link is disconnected, and the laser emission module 11 unconditionally cuts off its output. In other words, the control circuit maintains the output of the infrared energy-transmitting laser beam from the transmitting device 1 when all the anti-interference modules corresponding to multiple photodiodes output DC logic levels (at which point the condition of detecting reflected light with matching polarization direction and modulation frequency is met); otherwise, it cuts off the output of the infrared energy-transmitting laser beam from the transmitting device 1.

[0025] In addition, the control circuit also includes a start-up trigger module, which is used to send a bypass start signal to the enable control terminal after the system initially establishes a connection or the link is interrupted. It can be implemented by one or more combinations of manual trigger switch, wireless communication handshake circuit, and microcontroller timing pulse output circuit.

[0026] In this embodiment, the laser beam output by the laser emitting module 11 is linearly polarized light with a first polarization direction. The polarization discrimination element in front of each photodiode in the reflected light detection module 12 has a transmission axis orthogonal to the first polarization direction, forming a second polarization direction. The phase delay element of the receiving device 2, in conjunction with the retroreflector 22, converts the incident linearly polarized light with the first polarization direction into the outgoing linearly polarized light with the second polarization direction. This forms an optical key closed loop: only the reflected light processed by the phase delay element and retroreflector 22 in the receiving device 2 can penetrate the polarization discrimination element of the reflected light detection module 12 and be received by the photodiode. Light reflected from ordinary mirror objects, maintaining the first polarization direction, cannot penetrate this polarization discrimination element, thus completely eliminating deceptive attacks from mirror reflections. Existing photoelectric detection technologies are easily interfered with by sunlight (strong DC light) or indoor LEDs or fluorescent lamps (low-frequency flashing), leading to a fatal danger of "false triggering" when the optical path is blocked. Photodiodes only generate effective logic levels for reflected light carrying specific high frequencies (such as 100kHz), and by using filtering circuits, they completely shield the interference of sunlight and lighting sources at the physical level, ensuring absolute safety under high power transmission of tens of watts.

[0027] In high-power laser transmission at the tens of watts level, if the optical path is interrupted by highly reflective foreign objects such as ordinary mirrors or smooth metals, the foreign objects will not only reflect the high-energy laser to a dangerous area, but their surface reflections may also "deceive" the photodiode of the transmitting device 1, allowing the laser beam to maintain high-power output. This invention constructs an "optical encryption and decryption" closed loop by placing a polarization discrimination element (such as horizontal polarization) in front of the photodiode of the transmitting device 1 and a quarter-wave plate in front of the retroreflector 22 of the receiving device 2. Lasers reflected by ordinary mirrors retain their polarization state and are blocked by the polarization discrimination element of the transmitting device 1, resulting in an instantaneous and safe system cutoff. Only laser beams meeting specific requirements are rotated 90 degrees and received by the photodiode. This mechanism perfectly solves the most challenging problem in high-power laser energy transmission—the "mirror object deception" problem—with extremely low optical thin-film costs.

[0028] like Figure 2 and Figure 4 The diagram illustrates the working principle of this invention. A modulation signal generator produces a specific high-frequency signal; in this embodiment, a 100kHz square wave signal is preferred. This signal is input to the laser driving circuit and superimposed on the bias current of the laser, causing the laser intensity output by the laser emitting module 11 to change synchronously with the modulation signal, forming a light-modulated output carrying frequency characteristics. The infrared energy-transmitting laser beam output by the laser emitting module 11 carries a 100kHz modulation frequency characteristic. It should be noted that the modulation depth can be adjusted according to actual needs; preferably, the modulation depth is less than 10% to ensure that the high-power energy transfer efficiency is not significantly affected.

[0029] When the laser beam illuminates the retroreflector 22 at the receiving end or the surface of a foreign object, the reflected light is received by the photodiode in the transmitting end device 1, such as... Figure 4 As shown, - This refers to a photodiode, and multiple photodiodes can be connected in series. The mixed electrical signal output by a photodiode contains two main components: first, interference signals generated by ambient light (such as sunlight or indoor lighting), the intensity of which may be much greater than the effective signal; and second, an AC component generated by reflected laser light, the frequency of which is the same as the modulation frequency (100kHz).

[0030] The mixed signal first enters the DC blocking capacitor. By utilizing the physical property of capacitors that "pass alternating current and block direct current", DC blocking capacitors are used. The large DC component generated by ambient light is completely filtered out, retaining only the AC signal carrying the modulation frequency. This step physically eliminates the impact of strong DC interference such as sunlight on subsequent circuits without relying on any software algorithms.

[0031] The AC signal after DC blocking enters the hardware. In this embodiment, the frequency identification circuit is preferably constructed using the LM567 phase-locked loop audio decoding chip. This chip integrates a phase-locked loop and a quadrature phase detector. Its output pin (e.g., pin 8) only transitions from high to low when the input signal frequency matches the internal voltage-controlled oscillator frequency (e.g., 100kHz), outputting a valid signal. This means it internally includes the functions of a bandpass filter and comparator. Compared to ordinary RC bandpass filters, the LM567 has higher frequency selectivity and anti-interference capability, and is purely hardware-based with a response time of less than 10 microseconds. This step physically eliminates high-frequency AC interference signals from the lighting lamp. The output of the LM567 is connected to the enable control terminal of the laser emitting module 11 via an inverting circuit (e.g., an inverter or a PNP transistor). This ensures that when all reflected light detection modules 12 simultaneously detect the required reflected light, the enable terminal receives a high level, and the laser emitting module 11 maintains light emission; when any condition is not met, the enable terminal receives a low level, and the laser emitting module 11 unconditionally cuts off the output. Furthermore, in Figure 4 middle, This is a bias resistor. and These are the timing resistor and timing capacitor, used to select the signal reference frequency. For output filter capacitor, For loop filter capacitors, For inverters, an additional inverter is needed when the output logic level is opposite to the laser definition.

[0032] Actual measurements show that, under direct sunlight (illuminance greater than 100,000 lux), the hardware anti-interference circuit of this embodiment can stably identify a 100kHz reflected laser signal with a false trigger rate of zero. When the reflected laser signal is blocked, the system cuts off the high-power output within 50 microseconds, which is significantly better than traditional software filtering schemes (response time is typically greater than 10 milliseconds).

[0033] like Figure 2 and Figure 4 As shown, this embodiment constructs a closed-loop "optical encryption and decryption" system, the core of which lies in the collaborative operation of the optical elements in the transmitting device 1 and the receiving device 2: The transmitter is "encrypted": the laser emission module 11 outputs linearly polarized light with a vertical polarization direction (the first polarization direction). At the same time, a horizontal polarizer (with the transmission axis horizontal and orthogonal to the laser polarization direction) is placed in front of each photodiode in the transmitter, forming a "lock" structure.

[0034] "Decryption" at the receiver: A quarter-wave plate (QWP) is placed in front of the corner prism at the receiver, with its fast axis at a 45° angle to the polarization direction of the incident laser. This wave plate and the corner prism together form a "key" structure.

[0035] like Figure 5 As shown, the vertically polarized light output from the laser travels through free space to the receiver, first passing through a quarter-wave plate. According to the principles of polarization optics, linearly polarized light changes its polarization state after passing through a quarter-wave plate whose fast axis is at a 45° angle to the polarization direction. After being reflected by a cornerstone prism, it passes through the quarter-wave plate again, and the polarization direction of the outgoing light rotates by 90° relative to the incident light, changing from vertical polarization to horizontal polarization. This horizontally polarized reflected light returns to the transmitter and illuminates a horizontal polarizer in front of the photodiode. Since the polarization direction of the reflected light is consistent with the transmission axis of the polarizer (both are horizontal), the light is completely transmitted and received by the photodiode. The photodiode converts the optical signal into an electrical signal, which, after processing by subsequent circuitry, maintains the high-power laser beam output.

[0036] like Figure 6As shown, when a highly reflective object such as a common mirror or smooth metal enters the optical path, the vertically polarized light output by the laser directly illuminates the surface of the object. The physical characteristic of ordinary mirror reflection is that the polarization state of the reflected light remains consistent with the incident light (unless at special angles such as the Brewster angle, which is generally not possible at typical entry angles). Therefore, the reflected light remains vertically polarized. This vertically polarized reflected light returns to the emitting end and illuminates the horizontal polarizer in front of the photodiode. Since the polarization direction (vertical) of the reflected light is orthogonal to the transmission axis (horizontal) of the polarizer, according to Malus's law, the light is completely blocked and cannot penetrate the polarizer to reach the photodiode. The photodiode outputs no signal, the hardware series logic link is immediately broken, the laser drive circuit is cut off, and the high-power laser output is rapidly terminated (generally within 50 microseconds), completely eliminating the safety risk.

[0037] The above embodiments provide a detailed description of the present invention. Specific examples have been used to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A safety interlocking system for long-distance wireless charging using infrared laser, characterized in that, It includes a transmitter (1), a receiver (2), and a control circuit; The transmitting device (1) includes a laser emitting module (11) for outputting an infrared energy-transmitting laser beam, a reflected light detection module (12) for receiving reflected light from the infrared energy-transmitting laser beam, and an anti-interference module for filtering out light interference. The infrared energy-transmitting laser beam has a pulse modulation signal of a preset frequency and a preset first polarization direction. The reflected light detection module (12) includes multiple photodiodes distributed around a preset center point, used to convert optical signals into photocurrents; The anti-interference module is used to filter out light rays with only the second polarization direction that are incident on the photodiode, and then convert the photocurrent component output by the photodiode with the same frequency as the pulse modulation signal into a DC logic level. The receiving device (2) includes a photoelectric conversion module (21) for receiving an infrared energy-transmitting laser beam and converting it into electrical energy, and also includes at least one retroreflector (22) disposed around the photoelectric conversion module (21) for converting the first polarization direction of a portion of the incident infrared energy-transmitting laser beam into a second polarization direction and reflecting it back to the transmitting device (1) along the original path. The control circuit is used to maintain the output of the infrared energy transmission laser beam of the transmitting device (1) when the anti-interference modules corresponding to multiple photodiodes all output DC logic level, otherwise cut off the output of the infrared energy transmission laser beam of the transmitting device (1).

2. The safety interlocking system according to claim 1, characterized in that, The anti-interference module includes a polarization discrimination element disposed on the light-incident surface of the photodiode, the transmission axis of which is consistent with the second polarization direction. It also includes a filter module electrically connected to the output terminal of the photodiode, which is used to convert the photocurrent component with the same frequency as the pulse modulation signal in the photocurrent output by the photodiode into a DC logic level.

3. The safety interlocking system according to claim 1, characterized in that, The incident surface of the retroreflector (22) is provided with a phase delay element, which, in conjunction with the retroreflector (22), rotates the infrared energy-transmitting laser beam from the first polarization direction to the second polarization direction.

4. The safety interlocking system according to claim 1, characterized in that, The control circuit also includes a start-up trigger module, which is used to send a bypass start signal to the enable control terminal after the system initially establishes a connection or the link is interrupted.

5. The safety interlocking system according to claim 1, characterized in that, The laser emitting module (11) includes a high-power energy transfer mode and a low-power pathfinding mode. When the system initially establishes a connection or restarts after a link interruption, the control circuit controls the laser emitting module (11) to switch to the low-power pathfinding mode to output an infrared energy transfer laser beam with power conforming to a preset standard and frequency of a preset frequency. When the anti-interference module corresponding to each photodiode outputs a DC logic level, the control circuit controls the laser emitting module (11) to switch to the high-power energy transfer mode to output an infrared energy transfer laser beam that meets the charging requirements.

6. The safety interlocking system according to claim 1, characterized in that, The wavelength of the infrared energy-transmitting laser beam is 800nm ​​to 1100nm, and the retroreflector (22) is a solid corner cone prism or a hollow retroreflector array 22.

7. The safety interlocking system according to claim 1, characterized in that, The first polarization direction is orthogonal to the second polarization direction.

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