Laser lens monitoring system and method based on light pressure sensing and memory alloy

Abstract

The invention relates to the technical field of laser welding equipment, in particular to a laser lens monitoring system based on light pressure sensing and memory alloy, which can detect the power state of a laser by arranging a laser state monitoring module, and timely detect whether the power of the laser is attenuated or not. The real-time state of the laser is mastered in time, and influence on welding quality is avoided; the lens state monitoring modules are arranged to detect the lens states of a plurality of lenses such as a collimating lens, a focusing lens and a protective lens, that is, the lens state monitoring modules are arranged at the positions of all the lenses, timely monitoring and alarming are achieved, monitoring is more comprehensive, the corresponding fault position can be rapidly positioned, and the fault detection efficiency is improved. The damage of the whole laser caused by the fact that one lens is not found in time is avoided. Meanwhile, the invention also provides a monitoring method adopting the laser lens monitoring system, the operation is simple, the feedback is timely, and the safety risk and loss are avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of laser welding equipment, and in particular to a laser lens monitoring system and method based on optical pressure sensing and memory alloy. Background Art

[0002] In the field of laser welding technology, the laser output power will gradually decay due to dirt or damage during long-term use. If the laser attenuation exceeds the critical value, it will lead to insufficient laser output power. Insufficient output power will cause defects such as incomplete fusion and incomplete welding, which will affect the accuracy of the results or cause economic losses in production. Usually, the laser gun head mainly contains collimating lenses, focusing lenses and protective lenses. Failure or damage of any of these lenses will cause insufficient laser output power. When the lens in the laser gun head is damaged and not discovered in time, the laser or the high temperature generated by the laser may cause damage to the high-value laser gun head as a whole, resulting in greater losses.

[0003] Existing technology can only monitor the overall temperature of the laser tip. When a high-temperature alarm is generated, engineers or technicians cannot quickly locate the fault. Furthermore, due to technical limitations or limited space within the laser tip, existing laser tips can only monitor the protective lens for contamination. There is a lack of effective monitoring methods for the collimating and focusing lenses, making comprehensive monitoring of the multiple lenses in the laser impossible. To address these issues, existing technology needs further improvement. Summary of the Invention

[0004] The object of the present invention is to provide a laser lens monitoring system and method based on optical pressure sensing and memory alloy to solve the existing technical problems existing in the above background technology.

[0005] In order to solve the above technical problems, the technical solution provided by the present invention is: On the one hand, the present application provides a laser lens monitoring system based on optical pressure sensing and memory alloy, including a collimating lens, a focusing lens, a protective lens, a laser state monitoring module, a lens state monitoring module and a data processing module. The collimating lens, focusing lens and protective lens are arranged in sequence downward along the laser source. The laser state monitoring module is arranged between the collimating lens and the focusing lens, and is used to detect the laser power to determine the laser state. The lens state monitoring modules are respectively arranged at the collimating lens, focusing lens and protective lens, and are used to detect the lens states of the collimating lens, focusing lens and protective lens. The data processing module is electrically connected to the laser state monitoring module and the lens state monitoring module.

[0006] Based on the above technical solution, the laser state monitoring module includes a fixed frame, a first reflector, a second reflector, a light pressure sensor and a third reflector. A hollow channel allowing laser to pass through is provided inside the fixed frame. The first reflector and the third reflector are tilted and symmetrically arranged in the hollow channel. The second reflector is arranged in the hollow channel and on the side opposite to the first reflector. The light pressure sensor is fixedly arranged on the side of the second reflector away from the first reflector. The light pressure sensor is electrically connected to the data processing module.

[0007] Based on the above technical solution, a first status indicator light is provided on the outer side wall of the fixed frame.

[0008] Based on the above technical solution, the lens status monitoring module includes a lens base, a memory alloy metal ring and a pressure sensor. An annular through hole is provided in the lens base, and a lens groove for mounting the lens is provided on the inner side wall of the annular through hole. The memory alloy metal ring and the pressure sensor are arranged in the lens groove and in sequence below the lens. The pressure sensor is electrically connected to the data processing module.

[0009] Based on the above technical solution, a second status indicator light and a push-pull handle are provided on the outer side wall of the lens base.

[0010] Based on the above technical solution, the lens state monitoring module further includes a lens pressing plate, which is fixedly connected to the lens base to press the lens onto the lens base.

[0011] Based on the above technical solution, the memory alloy metal ring is made of nickel-titanium alloy.

[0012] On the other hand, the present application also provides a laser lens monitoring method based on optical pressure sensing and memory alloy, which uses the laser lens monitoring system and includes the following steps: Turn on the laser and introduce laser light to sequentially pass through the collimating lens and the lens status monitoring module thereon, the laser status monitoring module, the focusing lens and the lens status monitoring module thereon, and the protective lens and the lens status monitoring module thereon; Receive the pressure value corresponding to the actual laser power detected by the laser status monitoring module; The data processing module determines the power status of the laser according to the pressure value corresponding to the actual laser power; receiving a temperature change of the lens detected by a lens status monitoring module; The data processing module determines the contamination status of the lens based on temperature changes.

[0013] Based on the above technical solution, determining the power state of the laser includes the following steps: Establish the relationship between laser power and pressure, and store the data in the data processing module corresponding to the laser status monitoring module; The data processing module reads the preset theoretical power of the laser and retrieves the corresponding theoretical pressure value F1; When the laser passes through the collimator lens and enters the laser status monitoring module, the data processing module extracts the actual pressure value F2 through the optical pressure sensor and compares it with the theoretical pressure value F1; If the error is within the preset range, the laser state is normal; if the error exceeds the preset range, the laser state is abnormal and the laser state monitoring module alarms.

[0014] Based on the above technical solution, the method of determining the contamination status of the lens includes the following steps: When the temperature of the lens changes, the temperature of the memory alloy metal ring increases; When the temperature exceeds the critical temperature of the memory alloy metal ring, the memory alloy metal ring undergoes phase change and deformation; The pressure sensor detects the pressure generated by the deformation of the memory metal ring; When the pressure exceeds the preset value, the data processing module outputs a signal and issues an alarm.

[0015] The beneficial effects of the technical solution provided by the present invention are: The present invention provides a laser lens monitoring system based on optical pressure sensing and memory alloy. By setting a laser state monitoring module, the laser power state can be detected, whether the laser power is attenuated can be detected in time, and the real-time state of the laser can be grasped in time to avoid affecting the welding quality. By setting a lens state monitoring module, the lens states of multiple lenses such as collimating lenses, focusing lenses and protective lenses can be detected. That is, a lens state monitoring module is set at the position of each lens, and timely monitoring and alarm are carried out. The monitoring is more comprehensive, and the corresponding fault position can be quickly located to avoid damage to the entire laser due to failure to detect damage to a certain lens in time.

[0016] This application also provides a laser lens monitoring method based on optical pressure sensing and memory alloy. The above-mentioned laser lens monitoring system is simpler to operate and provides timely system feedback, which makes it convenient for operators to promptly identify changes in the status of the laser or lens. At the same time, the fault can be quickly located, avoiding possible safety risks and usage risks. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Schematic diagram of the structure principle of the laser in the present invention; Figure 2 It is a structural diagram of the laser state monitoring module in the present invention; Figure 3is a cross-sectional schematic diagram of the laser state monitoring module of the present invention; Figure 4 It is a structural diagram of the lens status monitoring module in the present invention; Figure 5 is a cross-sectional schematic diagram of the lens status monitoring module of the present invention; Figure 6 This is a schematic structural diagram of the memory alloy metal ring at low temperature in the present invention; Figure 7 It is a schematic structural diagram of the memory alloy metal ring at high temperature in the present invention; DETAILED DESCRIPTION The present invention will be further described below with reference to the accompanying drawings and examples: In the present invention, unless otherwise expressly specified or limited, terms such as "mounted," "connected," "connect," and "fixed" should be understood broadly. For example, they may refer to fixed connection, detachable connection, or integration; they may refer to direct connection or indirect connection through an intermediate medium; they may refer to internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0018] In the description of the present invention, it should be understood that the terms "left", "right", "front", "back", "top", "bottom", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they should not be understood as limiting the present invention.

[0019] like Figures 1 to 7 As shown, a laser lens monitoring system based on optical pressure sensing and memory alloy includes a collimator lens 1, a focusing lens 2, a protective lens 3, a laser state monitoring module 4, a lens state monitoring module and a data processing module. The collimator lens 1, the focusing lens 2 and the protective lens 3 are arranged in sequence downward along the laser source. The laser state monitoring module 4 is arranged between the collimator lens 1 and the focusing lens 2, and is used to detect the laser power to determine the laser state. The lens state monitoring modules are respectively arranged at the collimator lens 1, the focusing lens 2 and the protective lens 3, and are used to detect the lens states of the collimator lens 1, the focusing lens 2 and the protective lens 3. The data processing module is electrically connected to the laser state monitoring module 4 and the lens state monitoring module.

[0020] The present invention provides a laser lens monitoring system based on optical pressure sensing and memory alloy. By setting a laser state monitoring module 4, the laser power state can be detected, whether the laser power is attenuated can be detected in time, and the real-time state of the laser can be grasped in time to avoid affecting the welding quality. By setting a lens state monitoring module, the lens states of multiple lenses such as the collimating lens 1, the focusing lens 2 and the protective lens 3 can be detected. That is, a lens state monitoring module is set at the position of each lens, and timely monitoring and alarm are performed. The monitoring is more comprehensive, and the corresponding fault position can be quickly located to avoid damage to the entire laser due to failure to detect damage to a certain lens in time.

[0021] The function of the collimating lens is to convert the disordered divergent laser into a parallel laser beam; the function of the focusing lens is to focus the parallel laser beam into a converged laser; the function of the protective lens is to prevent smoke and high-temperature splashes from damaging the focusing lens.

[0022] At the same time, placing the laser state monitoring module 4 between the collimating lens 1 and the focusing lens 2 can ensure the detection accuracy. This is also related to the role of the above-mentioned collimating lens, that is, the laser is not parallel light before entering the collimating lens, and there is scattered light, which will affect the detection accuracy.

[0023] Based on the above technical solution, the laser state monitoring module 4 includes a fixed frame 41, a first reflector 42, a second reflector 43, a light pressure sensor 44 and a third reflector 45. A hollow channel allowing laser to pass through is provided inside the fixed frame 41. The first reflector 42 and the third reflector 45 are tilted and symmetrically arranged in the hollow channel. The second reflector 43 is arranged in the hollow channel and on the side opposite to the first reflector 42. The light pressure sensor 44 is fixedly arranged on the side of the second reflector 43 away from the first reflector 42. The light pressure sensor 44 is electrically connected to the data processing module.

[0024] Traditional laser power measurement mainly uses calorimetry and sampling methods. The calorimetry method has a large device volume and mass, and the higher the measured power, the larger the device volume. The absorbing material surface of the measuring device is easily damaged by the laser. Although the sampling method has the advantage of a smaller device volume, it has extremely high requirements on the accuracy and stability of the laser sampling ratio. Compared with the calorimetry method, the measurement error is large and the stability is poor.

[0025] The use of a light pressure sensor 44 in the laser state monitoring module of this application successfully solves the above-mentioned problems of complex laser power measurement or poor measurement accuracy and stability. Although photons do not have a rest mass, they have momentum. When the laser is irradiated on the surface of an object, pressure is generated. By utilizing the pressure effect of light, the laser power can be directly traced back to the mass, providing a new idea for high-power laser measurement. Compared with traditional calorimetric methods, this method has the advantages of fast response speed and high measurement accuracy. The higher the measured laser power, the better the signal-to-noise ratio of the result. In theory, the greater the measured laser power, the smaller the measurement uncertainty. Therefore, the light pressure method has significant advantages when measuring high-power lasers.

[0026] Based on the above technical solution, a first status indicator light 46 is provided on the outer wall of the fixed frame 41. The first status indicator light can provide timely feedback on the power status of the laser, making it easier for operators to detect changes in the power status of the laser and making operation more convenient.

[0027] The working principle of the laser state monitoring module 4 is: 1. Establish the relationship between laser power and pressure, and write the data into the laser status monitoring module; 2 During operation, the laser status monitoring module reads the laser power set by the laser software or the equipment system and retrieves the corresponding pressure F1; 3. When the laser passes through the collimator lens and enters the laser status monitoring module, the module extracts the pressure value F2 through the 34 optical pressure sensor; 4 The laser status monitoring module compares F2 with F1. If the error is within the set range, the laser status is considered normal and the first status indicator light is green. If the error exceeds a certain set range, the laser status is considered abnormal and the laser status monitoring module system alarms to remind process or production personnel to pay attention to the laser status. The first status indicator light is yellow. If the error exceeds a larger set range, the laser status is considered seriously abnormal and the first status indicator light is red. The laser status monitoring module outputs a signal to interrupt the welding process to prevent greater losses.

[0028] Based on the above technical solution, the lens status monitoring module includes a lens base 51, a memory alloy metal ring 52 and a pressure sensor 53. An annular through hole is provided in the lens base 51, and a lens groove 54 for mounting the lens is provided on the inner side wall of the annular through hole. The memory alloy metal ring 52 and the pressure sensor 53 are arranged in the lens groove 54 and are arranged in sequence below the lens. The pressure sensor 53 is electrically connected to the data processing module.

[0029] It is understandable that the lens mentioned here can be a collimating lens, a focusing lens or a protective lens, depending on the actual installation position.

[0030] Based on the above technical solution, a second status indicator light 55 and a push-pull handle 56 are provided on the outer wall of the lens base 51. The second status indicator light 55 provides timely feedback on the lens status, allowing the operator to promptly detect changes in the lens status and making operation more convenient. At the same time, a push-pull handle 56 is provided on the outer side of the lens base 51 to facilitate inspection or replacement of the lens.

[0031] Based on the above technical solution, the lens status monitoring module further includes a lens pressing piece 57, which is fixedly connected to the lens base 51 and presses the lens against the lens base 51. By providing the lens pressing piece, the lens, the memory alloy metal ring, and the pressure sensor are pressed together. The pressure sensor can promptly and effectively sense the pressure signal generated by the changes in the memory alloy metal ring, making detection more accurate.

[0032] The working principle of the lens status monitoring module is: When the lens is not dirty, the second status indicator light 55 is green; when the lens is dirty, the laser transmittance decreases, causing the lens temperature to rise; the temperature of the memory alloy metal ring 52 rises at the junction of the lens and the memory alloy metal ring 52; when the temperature exceeds the critical temperature of the memory alloy, the memory alloy metal ring 52 is deformed, and the pressure sensor 53 outputs pressure. When the pressure value exceeds the set value, the data processing system outputs a signal, and the status indicator light changes to yellow or red; when the second status indicator light 55 is yellow, it reminds the process or production personnel to pay attention to the lens status; when the second status indicator light 55 is red, the data processing system outputs a signal to interrupt the welding process to prevent greater losses.

[0033] Based on the above technical solution, the memory alloy metal ring 52 is made of nickel-titanium alloy.

[0034] The deformation temperature range of memory metals mainly depends on changes in their composition and crystal structure. The phase transition temperature Af point of memory metals can be precisely controlled between -100°C and +110°C, with an error of no more than 1°. In this embodiment, a memory alloy made of nickel-titanium alloy is used as an example. Its crystal structure above 40°C has a high degree of symmetry, while at temperatures below 40°C, the crystal structure transforms into a martensitic variant. When the metal wire is stretched and deformed, the martensitic variant gradually unifies into a single orientation. At this time, if the temperature is suddenly raised to above 40°C, the martensite will undergo a reverse transformation and return to the original single-oriented high-temperature phase.

[0035] In this embodiment, a metal ring made of nickel-titanium shape memory alloy is used, such as Figure 6 and Figure 7 In the ring structure, under normal conditions, the nickel-titanium memory alloy is a wavy structure, which is processed into the following in this application: Figure 7 The straight ring structure shown in the figure will deform when the metal ring is used at high temperature, that is, when it exceeds its critical temperature of phase change, and return to its original state. Figure 6 The wave-like structure shown in .

[0036] This embodiment also provides a laser lens monitoring method based on optical pressure sensing and memory alloy, which uses the above-mentioned laser lens monitoring system and includes the following steps: Turn on the laser and introduce laser light to sequentially pass through the collimating lens 1 and the lens state monitoring module thereon, the laser state monitoring module 4, the focusing lens and the lens state monitoring module thereon, and the protective lens and the lens state monitoring module thereon; Receive the pressure value corresponding to the actual laser power detected by the laser state monitoring module 4; The data processing module determines the power status of the laser according to the pressure value corresponding to the actual laser power; receiving a temperature change of the lens detected by a lens status monitoring module; The data processing module determines the contamination status of the lens based on temperature changes.

[0037] This application also provides a laser lens monitoring method based on optical pressure sensing and memory alloy. The above-mentioned laser lens monitoring system is simpler to operate and provides timely system feedback, which makes it convenient for operators to promptly identify changes in the status of the laser or lens. At the same time, the fault can be quickly located, avoiding possible safety risks and usage risks.

[0038] Based on the above technical solution, determining the power state of the laser includes the following steps: Establish the relationship between laser power and pressure, and store the data in the data processing module corresponding to the laser state monitoring module 4; The data processing module reads the preset theoretical power of the laser and retrieves the corresponding theoretical pressure value F1; When the laser passes through the collimator lens 1 and enters the laser state monitoring module 4, the data processing module extracts the actual pressure value F2 through the optical pressure sensor 44 and compares it with the theoretical pressure value F1; If the error is within the preset range, the laser state is normal; if the error exceeds the preset range, the laser state is abnormal and the laser state monitoring module alarms.

[0039] In a preferred embodiment, if the error between the actual pressure value F2 and the theoretical pressure value F1 exceeds a preset range A, the laser power state is deemed abnormal, and the laser state monitoring module 4 issues an alarm to remind the process or production personnel to pay attention to the laser state; In a more preferred embodiment, if the error between the actual pressure value F2 and the theoretical pressure value F1 exceeds the preset range B, where the preset range B is larger than the preset range A, it is judged that the laser power state is seriously abnormal, and the laser state monitoring module 4 outputs a corresponding signal to interrupt the welding process to prevent greater losses.

[0040] Based on the above technical solution, the method of determining the contamination status of the lens includes the following steps: When the temperature of the lens changes, the temperature of the memory alloy metal ring 52 increases; When the temperature exceeds the critical temperature of the memory alloy metal ring 52, the memory alloy metal ring 52 undergoes phase change and deformation; The pressure sensor 53 detects the pressure generated by the deformation of the memory metal ring 52; When the pressure exceeds the preset value, the data processing module outputs a signal and issues an alarm.

[0041] Specifically, when the lens is not dirty, that is, when the lens is in normal condition, the status indicator light is green; when the lens is dirty, the laser transmittance decreases, causing the lens temperature to rise; at the junction of the lens and the memory alloy metal ring 52, the temperature of the memory alloy metal ring 52 rises; when the temperature exceeds the critical temperature of the memory alloy, the metal sheet deforms, and the pressure sensor 53 outputs pressure; if the pressure exceeds the preset value, the data processing module outputs a signal, and the second status indicator light 55 turns yellow or red. When the second status indicator light 55 is yellow, it reminds the process or production personnel to pay attention to the lens status; when the second status indicator light 55 is red, the data processing system outputs a signal to interrupt the welding process to prevent greater losses.

[0042] It can be understood that the data processing module in the present application adopts a PLC module, which is a common control method in the technical field.

[0043] The basic principles and main features of the present invention are shown and described above. It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments. Therefore, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, it is intended that all changes that fall within the meaning and scope of the equivalent elements of the claims are included in the present invention.

[0044] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A laser lens monitoring system based on optical pressure sensing and memory alloy, characterized in that: The invention comprises a collimating mirror (1), a focusing mirror (2), a protective mirror (3), a laser state monitoring module (4), a lens state monitoring module and a data processing module. The collimating mirror (1), the focusing mirror (2) and the protective mirror (3) are sequentially arranged downward along the laser source. The laser state monitoring module (4) is arranged between the collimating mirror (1) and the focusing mirror (2) and is used to detect the laser power to judge the laser state. The lens state monitoring modules are respectively arranged at the collimating mirror (1), the focusing mirror (2) and the protective mirror (3) and are used to detect the lens states of the collimating mirror (1), the focusing mirror (2) and the protective mirror (3). The data processing module is electrically connected to the laser state monitoring module (4) and the lens state monitoring module.

2. The laser lens monitoring system based on optical pressure sensing and memory alloy according to claim 1, characterized in that: The laser state monitoring module (4) comprises a fixed frame (41), a first reflector (42), a second reflector (43), an optical pressure sensor (44) and a third reflector (45); a hollow channel for allowing laser light to pass through is provided inside the fixed frame (41); the first reflector (42) and the third reflector (45) are tilted and symmetrically arranged in the hollow channel; the second reflector (43) is arranged in the hollow channel and on a side opposite to the first reflector (42); the optical pressure sensor (44) is fixedly arranged on a side of the second reflector (43) away from the first reflector (42); and the optical pressure sensor (44) is electrically connected to the data processing module.

3. The laser lens monitoring system based on optical pressure sensing and memory alloy according to claim 1, characterized in that: A first status indicator light (46) is provided on the outer side wall of the fixed frame (41).

4. The laser lens monitoring system based on optical pressure sensing and memory alloy according to claim 1, characterized in that: The lens state monitoring module comprises a lens base (51), a memory alloy metal ring (52) and a pressure sensor (53); an annular through hole is provided in the lens base (51); a lens groove (54) for mounting a lens is provided on the inner side wall of the annular through hole; the memory alloy metal ring (52) and the pressure sensor (53) are arranged in the lens groove (54) and are sequentially arranged below the lens; and the pressure sensor (53) is electrically connected to the data processing module.

5. The laser lens monitoring system based on optical pressure sensing and memory alloy according to claim 4, characterized in that: A second status indicator light (55) and a push-pull handle (56) are provided on the outer side wall of the lens base (51).

6. The laser lens monitoring system based on optical pressure sensing and memory alloy according to claim 4, characterized in that: The lens state monitoring module further comprises a lens pressing piece (57), wherein the lens pressing piece (57) is fixedly connected to the lens base (51) to press the lens onto the lens base (51).

7. The laser lens monitoring system based on optical pressure sensing and memory alloy according to claim 1, characterized in that: The memory alloy metal ring (52) is made of nickel-titanium alloy.

8. A laser lens monitoring method based on optical pressure sensing and memory alloy, using the laser lens monitoring system according to any one of claims 1 to 7, characterized in that: The following steps are involved: The laser is turned on and the laser is introduced to sequentially pass through the collimating mirror (1) and the lens state monitoring module thereon, the laser state monitoring module (4), the focusing mirror and the lens state monitoring module thereon, and the protective mirror and the lens state monitoring module thereon; receiving a pressure value corresponding to the actual laser power detected by the laser state monitoring module (4); The data processing module determines the power status of the laser according to the pressure value corresponding to the actual laser power; receiving a temperature change of the lens detected by a lens status monitoring module; The data processing module determines the contamination status of the lens based on temperature changes.

9. The laser lens monitoring method based on optical pressure sensing and memory alloy according to claim 8, characterized in that: Determining the power status of the laser includes the following steps: Establishing the relationship between laser power and pressure, and storing the data in the data processing module corresponding to the laser state monitoring module (4); The data processing module reads the preset theoretical power of the laser and retrieves the corresponding theoretical pressure value F1; When the laser passes through the collimating lens (1) and enters the laser state monitoring module (4), the data processing module extracts the actual pressure value F2 through the optical pressure sensor (44) and compares it with the theoretical pressure value F1; If the error is within the preset range, the laser state is normal; if the error exceeds the preset range, the laser state is abnormal and the laser state monitoring module alarms.

10. The laser lens monitoring method based on optical pressure sensing and memory alloy according to claim 8, characterized in that: Determining the contamination status of the lens includes the following steps: When the temperature of the lens changes, the temperature of the memory alloy metal ring (52) increases; When the temperature exceeds the critical temperature of the memory alloy metal ring (52), the memory alloy metal ring (52) undergoes phase change and deformation; The pressure sensor (53) detects the pressure generated by the deformation of the memory metal ring (52); When the pressure exceeds the preset value, the data processing module outputs a signal and issues an alarm.

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