Laser head temperature control method and system

Abstract

The invention belongs to the technical field of lasers, and particularly relates to a laser head temperature control method and system. The laser head temperature control method comprises the steps that the environment temperature and the laser head temperature are obtained; setting the initial rotating speed of the fan according to the environment temperature, and determining the minimum rotating speed of the fan; controlling the rotating speed of a fan according to the laser head temperature and the laser head target temperature; when the temperature of the laser head is smaller than the minimum value of the preset range and the rotating speed of the fan is equal to the minimum rotating speed, a heating block is started for heating, and the temperature of the laser head is controlled through a PID algorithm. According to the laser head temperature control method, different laser head cavity materials can be automatically adapted, so that stable output of laser power is guaranteed; temperature imbalance in a laser head cavity caused by too fast heating can be avoided; the starting of the heating block is combined with the judgment of the rotating speed of the fan, the temperature is increased through the heat generated by the work of the laser head in the early stage, and after the rotating speed of the fan is at the minimum value, the heating block is started for heating if the temperature still does not reach the standard, so that the power consumption is effectively reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of lasers, and in particular relates to a laser head temperature control method and system. Background Art

[0002] Lasers, especially pulsed lasers, are widely used in industrial production. Due to their own characteristics, lasers release a lot of heat when working. Generally, the operating temperature range of lasers is 15 to 30°C, but the heat (temperature) generated by lasers under actual working conditions far exceeds this range. Therefore, precise and constant temperature control is one of the technical obstacles to laser applications.

[0003] The control method of the prior art is that when the temperature of the laser head is lower than the set value, the temperature of the laser head is increased by adding a heating block; when the temperature of the laser head is higher than the set value, the laser head is cooled by a fan.

[0004] The inventors found that the above method has many defects. For example, when the laser head is heated by the heating block, although PID temperature control is used, the difference in thermal conductivity of the laser head cavity material is not considered, and the temperature is only controlled towards the target temperature. When the actual temperature is very different from the target temperature, it will cause excessive heating in a short period of time, and the temperature in the laser head will be uneven, which will seriously affect the stable output of optical power. In addition, when the heating block is enabled for heating, the fan speed is not reduced to the minimum before starting the heating block. It is not considered to increase the temperature of the laser head to the target value through the heat generated by the laser head itself. It only pursues a rapid increase in temperature, and does not consider the problem of large fluctuations in optical power caused by excessive heating. Summary of the invention

[0005] The object of the present invention is to provide a laser head temperature control method and system.

[0006] In a first aspect, the present application provides a laser head temperature control method, comprising:

[0007] Get the ambient temperature and laser head temperature;

[0008] Set the initial speed of the fan and determine the minimum speed of the fan according to the ambient temperature;

[0009] Control the fan speed according to the laser head temperature and the laser head target temperature; and

[0010] When the laser head temperature is lower than the minimum value of the preset range and the fan speed is equal to the minimum speed, the heating block is turned on for heating and the laser head temperature is controlled by the PID algorithm.

[0011] In one embodiment of the present application, if the initial speed of the fan is less than the minimum speed of the fan, the speed of the fan is controlled according to the minimum speed of the fan.

[0012] In one embodiment of the present application, the method for controlling the fan speed according to the laser head temperature and the laser head target temperature includes:

[0013] Determine whether the laser head temperature is within the preset range;

[0014] If so, the fan speed remains unchanged;

[0015] If the laser head temperature is less than the minimum value of the preset range, determine whether the laser head temperature is less than the laser head temperature of the previous cycle; if so, control the fan to reduce the speed, otherwise the fan speed remains unchanged; and

[0016] If the laser head temperature is greater than the maximum value of the preset range, it is determined whether the laser head temperature is greater than the laser head temperature of the previous cycle; if so, the fan speed is controlled to increase, otherwise the fan speed remains unchanged.

[0017] In one embodiment of the present application, the method for controlling the fan to reduce the rotation speed includes:

[0018] Taking a preset time as a cycle, determining whether the cycle satisfies: the laser head temperature in the previous cycle - the laser head temperature > the first preset temperature difference;

[0019] If so, the fan speed is reduced to a preset value;

[0020] If not, the fan speed is maintained; and if it is still not satisfied for n consecutive cycles, the fan speed is reduced by a preset value.

[0021] In one embodiment of the present application, the method for controlling the fan to increase the speed includes:

[0022] Taking a preset time as a cycle, determining whether the cycle satisfies: laser head temperature - laser head temperature in the previous cycle > first preset temperature difference;

[0023] If yes, the fan speed is increased to a preset value;

[0024] If not, the fan speed is maintained; and if it is still not satisfied after n consecutive cycles, the fan speed is increased by a preset value.

[0025] In one embodiment of the present application, the fan speed is not greater than the maximum speed and not less than the minimum speed.

[0026] In one embodiment of the present application, the method for controlling the temperature of the laser head by using a PID algorithm includes:

[0027] After the heating block is started, the target temperature of the laser head increases in steps, with a preset time as one cycle;

[0028] If the laser head temperature is not less than the minimum laser head target temperature of the previous cycle, then the minimum laser head target temperature = laser head temperature + the second preset temperature difference;

[0029] If the laser head temperature is lower than the minimum laser head target temperature of the previous cycle, then the minimum laser head target temperature = the minimum laser head target temperature of the previous cycle + the second preset temperature difference;

[0030] If the minimum laser head target temperature is greater than the laser head target temperature, then the minimum laser head target temperature = the laser head target temperature.

[0031] In one embodiment of the present application, when the laser head temperature is within ±1° C. of the laser head target temperature and the fan speed is greater than the minimum speed, the heating block stops heating.

[0032] In a second aspect, the present application provides a laser head temperature control system, which adopts the laser head temperature control method as described above;

[0033] The laser head temperature control system comprises: a controller, and an ambient temperature sensor, a laser head temperature sensor, a heating block and a fan electrically connected to the controller; wherein

[0034] The ambient temperature sensor is used to collect ambient temperature;

[0035] The laser head temperature sensor is used to collect the temperature of the laser head.

[0036] The beneficial effects of the present invention are:

[0037] Different from the prior art, the present application provides a laser head temperature control method and system. The laser head temperature control method includes: obtaining the ambient temperature and the laser head temperature; setting the initial fan speed and determining the minimum fan speed according to the ambient temperature; controlling the fan speed according to the laser head temperature and the laser head target temperature; and when the laser head temperature is less than the laser head target temperature and the fan speed is equal to the minimum speed, turning on the heating block for heating, and controlling the laser head temperature through the PID algorithm. The laser head temperature control method of the present application can autonomously adapt to different laser head cavity materials to ensure the stable output of laser light power; it can avoid temperature imbalance in the laser head cavity due to excessive heating; the turning on of the heating block is combined with the judgment of the fan speed, and the temperature is increased in the early stage by the heat generated by the laser head itself. After the fan speed is at the minimum value, if the temperature still does not meet the standard, the heating block heating is started, which effectively reduces power consumption.

[0038] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention are realized and obtained by the structures particularly pointed out in the description and the drawings.

[0039] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0041] Figure 1 is a schematic diagram of a laser head temperature control system according to a preferred embodiment of the present invention;

[0042] Figure 2 is a schematic diagram of a laser head temperature control method according to a preferred embodiment of the present invention;

[0043] Figure 3 It is a schematic diagram of a method for controlling the fan speed according to the laser head temperature and the laser head target temperature according to a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0044] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0045] The present application provides a laser head temperature control method and system, which are described in detail below. It should be noted that the description order of the following embodiments does not limit the preferred order of the embodiments of the present application. In the following embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, please refer to the relevant description of other embodiments.

[0046] See also Figure 1 In some embodiments, the laser head temperature control system includes: a controller, and an ambient temperature sensor, a laser head temperature sensor, a heating block and a fan electrically connected to the controller; wherein the ambient temperature sensor is used to collect the ambient temperature; and the laser head temperature sensor is used to collect the laser head temperature.

[0047] In some embodiments, the laser head temperature control system uses a laser head temperature control method to control the temperature of the laser head.

[0048] See also Figure 2 In some embodiments, the laser head temperature control method includes: obtaining the ambient temperature and the laser head temperature; setting the initial fan speed and determining the minimum fan speed according to the ambient temperature; controlling the fan speed according to the laser head temperature and the laser head target temperature; and when the laser head temperature is less than the minimum value of the preset range and the fan speed is equal to the minimum speed, turning on the heating block for heating and controlling the laser head temperature through the PID algorithm.

[0049] In one embodiment, optionally, each time the laser is turned on, an initial speed of the fan can be preset according to the ambient temperature as shown in Table 1. According to the ambient temperature, the minimum speed of the fan is determined according to Table 2.

[0050] For convenience of representation, the speed is a percentage of the maximum speed. For example, 10% means that the speed is 10% of the maximum speed. It should be noted that if the initial speed of the fan is less than the minimum speed of the fan, the fan speed is controlled according to the minimum speed of the fan.

[0051] Table 1 Fan initial speed table

[0052] Ambient temperature ℃ Speed(%) EVT≤5 5 5<EVT≤8 15 8<EVT≤11 20 11<EVT≤14 22 14<EVT≤17 25 17<EVT≤20 28 20<EVT≤23 30 23<EVT≤26 45 26<EVT≤29 65 29<EVT≤32 75 32<EVT≤35 80 35<EVT≤38 90 38<EVT 100

[0053] Table 2 Minimum fan speed

[0054] Ambient temperature ℃ Minimum speed (%) EVT≤40 10 40<EVT≤43 15 43<EVT≤47 20 47<EVT≤50 23 50<EVT≤52 27 52<EVT≤52.2 29 EVT>53 35

[0055] Further, the method of controlling the fan speed according to the laser head temperature and the laser head target temperature includes: determining whether the laser head temperature is within a preset range;

[0056] If so, the fan speed remains unchanged;

[0057] If the laser head temperature is less than the minimum value of the preset range, determine whether the laser head temperature is less than the laser head temperature of the previous cycle; if so, control the fan to reduce the speed, otherwise the fan speed remains unchanged; and

[0058] If the laser head temperature is greater than the maximum value of the preset range, it is determined whether the laser head temperature is greater than the laser head temperature of the previous cycle; if so, the fan speed is controlled to increase, otherwise the fan speed remains unchanged.

[0059] For details, see Figure 3 In one embodiment, it is first determined whether the temperature of the laser head is within a preset range, for example, whether:

[0060] Laser head target temperature -1°C ≤ laser head temperature ≤ laser head target temperature +1°C;

[0061] The judgment result has three situations:

[0062] Case 1: When the laser head temperature is within this range, the fan speed remains unchanged;

[0063] Case 2: If the laser head temperature is less than the laser head target temperature -1°C, it is further determined whether the laser head temperature is less than the laser head temperature in the previous cycle; if so, it indicates that the laser head temperature has a downward trend, and the fan speed is controlled to decrease; if not, the fan speed remains unchanged;

[0064] Case 3: Laser head temperature > laser head target temperature + 1°C, then further determine whether the laser head temperature is greater than the laser head temperature in the previous cycle; if so, it means that the laser head temperature has an upward trend, and the fan is controlled to reduce the speed; if not, the fan speed remains unchanged.

[0065] Optionally, one minute may be used as a cycle. The target temperature of the laser head may be an empirical value or may be obtained through preliminary experiments. For example, through experimental testing, the temperature at which the output optical power is optimal is used as the target temperature of the laser head.

[0066] Furthermore, the method for controlling the fan to reduce the rotation speed includes:

[0067] Taking a preset time as a cycle, determining whether the cycle satisfies: the laser head temperature in the previous cycle - the laser head temperature > the first preset temperature difference;

[0068] If so, the fan speed is reduced to a preset value;

[0069] If not, the fan speed is maintained; and if it is still not satisfied for n consecutive cycles, the fan speed is reduced by a preset value.

[0070] Specifically, the first preset temperature difference may be relatively small, such as 0.3° C. That is, it is determined once every minute whether:

[0071] Laser head temperature in the previous cycle - laser head temperature > 0.3°C;

[0072] If yes, it means that the temperature of the laser head drops rapidly and the fan speed needs to be reduced, for example, by 5%. For example, if the current fan speed is 50%, minus 5%, the fan speed becomes 45%.

[0073] If not, it means that the temperature of the laser head does not drop quickly, and the fan speed may not be reduced in this cycle. However, if the condition is not met for n consecutive cycles (eg, 3 minutes or 4 minutes), the fan speed may be directly controlled to be reduced by 5%.

[0074] Furthermore, the method for controlling the fan to increase the speed includes:

[0075] Taking a preset time as a cycle, determining whether the cycle satisfies: laser head temperature - laser head temperature in the previous cycle > first preset temperature difference;

[0076] If yes, the fan speed is increased to a preset value;

[0077] If not, the fan speed is maintained; and if it is still not satisfied after n consecutive cycles, the fan speed is increased by a preset value.

[0078] Specifically, it is determined every minute whether the following conditions are met:

[0079] Laser head temperature - the laser head temperature in the previous cycle is > 0.3°C;

[0080] If yes, it means that the temperature of the laser head rises rapidly and the fan speed needs to be increased, for example, by 2%. For example, if the current fan speed is 50%, and 2% is added, the fan speed becomes 52%.

[0081] If not, it means that the laser head temperature rise is not fast, and the fan speed may not be reduced in this cycle. However, if the condition is not met for n consecutive cycles (eg, 3 minutes or 4 minutes), the fan speed may be directly controlled to increase by 2%.

[0082] It should be noted that the fan speed cannot be greater than the maximum speed, and the fan speed cannot be less than the minimum speed.

[0083] Furthermore, when the laser head temperature is lower than the minimum value of the preset range, for example, the laser head temperature is lower than the laser head target temperature - 1°C, and the fan speed is equal to the minimum speed, it means that the laser head temperature cannot be increased by adjusting the ambient temperature by adjusting the fan speed. Then, it is necessary to turn on the heating block for heating and control the laser head temperature by the PID algorithm.

[0084] Specifically, the method of controlling the temperature of the laser head by using the PID algorithm includes:

[0085] After the heating block is started, the target temperature of the laser head increases in a step-by-step manner, with a preset time (e.g., 1 minute) as a cycle;

[0086] If the laser head temperature is not less than the minimum laser head target temperature of the previous cycle, then the minimum laser head target temperature = laser head temperature + second preset temperature difference; for example, the second preset temperature difference may be 0.2°C;

[0087] If the laser head temperature is lower than the minimum laser head target temperature of the previous cycle, then the minimum laser head target temperature = the minimum laser head target temperature of the previous cycle + the second preset temperature difference;

[0088] If the minimum laser head target temperature is greater than the laser head target temperature, then the minimum laser head target temperature = the laser head target temperature.

[0089] For example, if the cycle is 1 minute, the second preset temperature difference is 0.2°C, the current laser head temperature is 25°C, and the minimum laser head target temperature in the previous cycle is 24°C, then the minimum laser head target temperature at this time is 25+0.2=25.2°C. After 1 minute, if the laser head temperature is 26°C, the minimum laser head target temperature in the previous cycle is 25.2°C, and 26°C is greater than 25.2°C, then the minimum laser head target temperature at this time is 26+0.2=26.2°C.

[0090] Further, when the laser head temperature is within ±1°C of the laser head target temperature and the fan speed is greater than the minimum speed, the heating block stops heating.

[0091] To sum up, the laser head temperature control method of the present application can autonomously adapt to different laser head cavity materials (i.e., environmental factors for temperature control) to ensure stable output of laser light power; it can avoid temperature imbalance in the laser head cavity caused by too rapid heating; the activation of the heating block is not simply a simple judgment of the difference between the current temperature and the target temperature, but is judged in combination with the fan speed. In the early stage, the temperature is increased as much as possible through some environmental factors such as the heat generated by the laser head itself. After the fan speed is at the minimum value, if the temperature still cannot be increased, the heating block is started to heat, which effectively reduces power consumption.

[0092] It should be noted that the various devices selected in this application (components whose specific structures are not described) are all universal standard parts or components known to technical personnel in this field, and their structures and principles can be known to technical personnel through technical manuals or through conventional experimental methods.

[0093] In the description of the embodiments of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0094] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0095] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some communication interfaces, and the indirect coupling or communication connection of devices or units can be electrical, mechanical or other forms.

[0096] Based on the above ideal embodiments of the present invention, the relevant staff can make various changes and modifications without departing from the technical concept of the present invention through the above description. The technical scope of the present invention is not limited to the contents of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A laser head temperature control method, characterized in that: include: Get the ambient temperature and laser head temperature; Set the initial speed of the fan and determine the minimum speed of the fan according to the ambient temperature; Control the fan speed according to the laser head temperature and the laser head target temperature; as well as When the laser head temperature is lower than the minimum value of the preset range and the fan speed is equal to the minimum speed, the heating block is turned on for heating and the laser head temperature is controlled by the PID algorithm.

2. The laser head temperature control method according to claim 1, characterized in that: If the initial speed of the fan is less than the minimum speed of the fan, the speed of the fan is controlled according to the minimum speed of the fan.

3. The laser head temperature control method according to claim 1, characterized in that: The method for controlling the fan speed according to the laser head temperature and the laser head target temperature includes: Determine whether the laser head temperature is within the preset range; If so, the fan speed remains unchanged; If the laser head temperature is less than the minimum value of the preset range, determine whether the laser head temperature is less than the laser head temperature of the previous cycle; if so, control the fan to reduce the speed, otherwise the fan speed remains unchanged; and If the laser head temperature is greater than the maximum value of the preset range, it is determined whether the laser head temperature is greater than the laser head temperature of the previous cycle; if so, the fan speed is controlled to increase, otherwise the fan speed remains unchanged.

4. The laser head temperature control method according to claim 3, characterized in that: The method for controlling the fan to reduce the rotation speed comprises: Taking a preset time as a cycle, determining whether the cycle satisfies: the laser head temperature in the previous cycle - the laser head temperature > the first preset temperature difference; If so, the fan speed is reduced to a preset value; If not, the fan speed is maintained; and if it is still not satisfied for n consecutive cycles, the fan speed is reduced by a preset value.

5. The laser head temperature control method according to claim 3, characterized in that: The method for controlling the fan to increase the speed includes: Taking a preset time as a cycle, determining whether the cycle satisfies: laser head temperature - laser head temperature in the previous cycle > first preset temperature difference; If yes, the fan speed is increased to a preset value; If not, the fan speed is maintained; and if it is still not satisfied after n consecutive cycles, the fan speed is increased by a preset value.

6. The laser head temperature control method according to claim 3, characterized in that: The fan speed shall not be greater than the maximum speed and not less than the minimum speed.

7. The laser head temperature control method according to claim 1, characterized in that: The method for controlling the temperature of the laser head by using a PID algorithm comprises: After the heating block is started, the target temperature of the laser head increases in steps, with a preset time as one cycle; If the laser head temperature is not less than the minimum laser head target temperature of the previous cycle, then the minimum laser head target temperature = laser head temperature + the second preset temperature difference; If the laser head temperature is lower than the minimum laser head target temperature of the previous cycle, then the minimum laser head target temperature = the minimum laser head target temperature of the previous cycle + the second preset temperature difference; If the minimum laser head target temperature is greater than the laser head target temperature, then the minimum laser head target temperature = the laser head target temperature.

8. The laser head temperature control method according to claim 1, characterized in that: Also includes: When the laser head temperature is within ±1°C of the laser head target temperature and the fan speed is greater than the minimum speed, the heating block stops heating.

9. A laser head temperature control system, characterized in that: Adopting the laser head temperature control method as described in any one of claims 1 to 8; The laser head temperature control system comprises: a controller, and an ambient temperature sensor, a laser head temperature sensor, a heating block and a fan electrically connected to the controller; wherein The ambient temperature sensor is used to collect ambient temperature; The laser head temperature sensor is used to collect the temperature of the laser head.

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