阅读说明：本技术 一种三维扫描式测风激光雷达扫描头结露点控制装置及方法 (Device and method for controlling condensation point of scanning head of three-dimensional scanning type wind measurement laser radar ) 是由 张灵乐 罗浩 陶波 朱敏强 李智 于 2021-07-21 设计创作，主要内容包括：本发明提供了一种三维扫描式测风激光雷达扫描头结露点控制装置,包括控制器主板、热敏电阻、湿度传感器、压力传感器；所述控制器主板,用于收集与外界测量的信号和算法处理；所述湿度传感器,用于采集湿度信号,与控制器主板电性连接及信号传送；所述压力传感器,用于采集压强信号,与控制器主板电性连接及信号传送；所述热敏电阻设置为多路电阻结构,用于测量多个温度点的温度,与控制器主板电性连接及信号传送。同时,还提供了使用上述装置的方法,通过将风扇加TEC温控器的环境温控方式,提供冷风和热风,并利用空气循环方式对扫描头内部空气进行温控,能够有效维持了内部整体的环境温度,而不是单一部位的温度。(The invention provides a three-dimensional scanning type wind lidar scanning head condensation point control device, which comprises a controller mainboard, a thermistor, a humidity sensor and a pressure sensor, wherein the controller mainboard is connected with the thermistor; the controller mainboard is used for collecting signals measured with the outside and processing the signals by an algorithm; the humidity sensor is used for acquiring a humidity signal, and is electrically connected with the controller mainboard and used for signal transmission; the pressure sensor is used for collecting pressure signals, and is electrically connected with the controller mainboard and used for signal transmission; the thermistor is arranged in a multi-path resistor structure and used for measuring the temperatures of a plurality of temperature points, and is electrically connected with the controller mainboard and used for signal transmission. Meanwhile, a method for using the device is also provided, cold air and hot air are provided in an environment temperature control mode of adding the fan and the TEC temperature controller, and the air in the scanning head is controlled in a temperature control mode in an air circulation mode, so that the whole environment temperature in the scanning head can be effectively maintained, and the temperature of a single part is not maintained.)

1. The utility model provides a three-dimensional scanning formula anemometry laser radar scanning head knot dew point controlling means which characterized in that: the controller comprises a controller mainboard, a thermistor, a humidity sensor and a pressure sensor; the controller mainboard is used for collecting signals measured with the outside and processing the signals by an algorithm; the humidity sensor is used for acquiring a humidity signal, and is electrically connected with the controller mainboard and used for signal transmission; the pressure sensor is used for collecting pressure signals, and is electrically connected with the controller mainboard and used for signal transmission; the thermistor is arranged in a multi-path resistor structure and used for measuring the temperatures of a plurality of temperature points, and is electrically connected with the controller mainboard and used for signal transmission.

2. The apparatus for controlling the dew-point of a scanning head of a three-dimensional scanning type wind lidar according to claim 2, wherein: also comprises a dehumidifier, a fan and a TEC temperature controller; the dehumidifier is connected with the controller mainboard and used for receiving signals and carrying out internal water vapor transportation treatment; the TEC temperature controller is arranged on the surface of the fan and is used for being matched with the fan to provide refrigeration or heating treatment; and the fan is connected with the controller mainboard and used for receiving the signals and then carrying out air supply processing.

3. The apparatus for controlling the dew-point of a scanning head of a three-dimensional scanning type wind lidar according to claim 2, wherein: when the controller main board carries out algorithm processing, a plurality of groups of temperature values in the scanning head are collected, dew point humidity under the environment temperature in the scanning head is obtained through calculation, and then a working signal is sent out.

4. The apparatus for controlling the dew-point of a scanning head of a three-dimensional scanning type wind lidar according to claim 3, wherein: when algorithm processing is carried out, the following formula (1) is adopted:

wherein, in the formula (1), T_dThe value of (A) is obtained by comparing the temperature of the window mirror with the temperature of the inner wall of the scanning head, two small temperature values are taken as calculated values, the value of T represents the ambient temperature, and a and b are correction numerical parameters.

5. The apparatus for controlling the dew-point of a scanning head of a three-dimensional scanning type wind lidar according to claim 4, wherein: when T is_dWhen the temperature difference value meets the requirement (0, T), obtaining the dew point humidity according to the formula (1), comparing the dew point humidity with the current humidity, calculating a difference value, and if the humidity difference value is smaller than a refrigeration highest threshold value, sending a signal for starting a fan and enabling a TEC temperature controller to be in a refrigeration state;

if the fan and the temperature control TEC are started for a long time, the humidity difference value is still smaller than the highest refrigerating threshold value, and when the humidity difference value is close to the lowest refrigerating threshold value, the dehumidifier is started to dehumidify the internal humidity, and the internal humidity processing signal is directly reduced.

6. The apparatus for controlling the dew-point of a scanning head of a three-dimensional scanning type wind lidar according to claim 4, wherein: when T is_dIf the temperature is less than 0, the calculation of the condensation point is not carried out according to the formula (1), and if the Td temperature is detected to be less than the lowest heating threshold value, the signals for starting the fan and enabling the TEC temperature controller to be in the heating state are sent out for processing; and if the temperature Td is detected to be lower than the highest heating threshold, sending a signal for stopping the fan and processing the signal that the TEC temperature controller is in the heating state.

7. The apparatus for controlling the dew-point of a scanning head of a three-dimensional scanning type wind lidar according to claim 4, wherein: when T is_dWhen the temperature is larger than T, the dew point calculation is not carried out through the formula (1), and signals of the closed states of the fan, the TEC temperature controller and the dehumidifier are sent out at the moment.

8. A method for controlling the dew point of a scanning head of a three-dimensional scanning type wind lidar according to any one of claims 1 to 7, wherein: comprises the following specific steps

(1) Preparation work

Electrifying the whole control device, collecting signals by the humidity sensor and the pressure sensor, and reading signals including but not limited to a plurality of paths of temperature values, humidity values and pressure values;

(2) data processing and sending out working signal

Comparing the temperature of the window mirror with the temperature of the inner wall of the scanning head, taking two values with small temperatures as Td calculated values to obtain the moisture of the condensation point, comparing the moisture with the current moisture value in a mode that the Td satisfies three intervals of being less than 0, being greater than T and being (0, T), and sending out corresponding working signals;

(3) end of work

And after the fan, the TEC temperature controller and the dehumidifier receive the corresponding signals, working until the end signal is received to complete the working cycle.

9. The method of claim 8, wherein the method comprises the following steps: in the step (2), when T is reached_dWhen the temperature difference value meets the requirement (0, T), obtaining the dew point humidity according to the formula (1), comparing the dew point humidity with the current humidity, calculating a difference value, and if the humidity difference value is smaller than a refrigeration highest threshold value, sending a signal for starting a fan and enabling a TEC temperature controller to be in a refrigeration state;

if the fan and the temperature control TEC are started for a long time, the humidity difference value is still smaller than the highest refrigerating threshold value, and when the humidity difference value is close to the lowest refrigerating threshold value, the dehumidifier is started to dehumidify the internal humidity, and the internal humidity processing signal is directly reduced.

10. The method of claim 8, wherein the method comprises the following steps: in the step (2),

when T is_dIf the temperature is less than 0, the calculation of the condensation point is not carried out according to the formula (1), and if the Td temperature is detected to be less than the lowest heating threshold value, the signals for starting the fan and enabling the TEC temperature controller to be in the heating state are sent out for processing; if the temperature Td is detected to be lower than the highest heating threshold, sending a signal for stopping the fan and processing the TEC temperature controller in a heating state;

when T is_dWhen the temperature is larger than T, the dew point calculation is not carried out through the formula (1), and signals of the closed states of the fan, the TEC temperature controller and the dehumidifier are sent out at the moment.

Technical Field

The invention belongs to the technical field of three-dimensional scanning type wind lidar, and particularly relates to a device and a method for controlling a junction point of a scanning head of the three-dimensional scanning type wind lidar.

Background

The three-dimensional scanning type wind measurement laser radar detects aerosol backscattering signals in the atmosphere according to a coherent Doppler wind measurement principle so as to acquire velocity division information, so that an object influencing a light path cannot exist in a transmitting path of detection light and a receiving path of reflected light, and if the whole light path is blocked, the signal-to-noise ratio of detection is reduced, and the velocity division data processing distortion or abnormality of the radar is caused. With the increasingly wide application of the three-dimensional scanning type wind measuring laser radar in the fields of urban meteorological detection, wind power resource assessment, local wind trimming early warning and the like, in order to reduce equipment maintenance and achieve the purpose of unattended operation, the absence of a detection light path becomes the first rigid requirement for ensuring the radar to operate.

The space in which dew condensation is most likely to occur in the entire optical path is the inside of the scanning head. Because the radar is operated outdoors, a sudden drop in air temperature or a sudden increase in water vapor in the air often occurs due to uncertainty of outdoor conditions, and even if the environmental conditions are good, part of the water vapor enters the interior of the scanning head. During the operation of the radar, a large amount of heat can be generated in the radar, and the phenomenon of condensation is generated after the external environment temperature is low and the scanning head enters a large amount of water vapor.

In addition, the humidity inside the scanning head is too high, which can cause water accumulation inside the scanning head and dew condensation inside the window mirror, so that the detection light beam cannot be completely emitted, and the detection performance can be reduced.

At present, a plurality of radars with scanning heads are internally provided with drying agents or humidity control pieces, and each scanning head sealing cover can be used for placing a dried drying agent and a dehumidification piece, and can be immediately sealed to prevent excessive water vapor from entering. And under the low temperature condition, the performance of scanner work also receives the influence, still need be equipped with the heating plate and be used for the heating of scanner inner wall, guarantees the performance of scanner.

The existing conventional specific method comprises the following steps: before the scanning head is covered, the drying agent and the humidity control sheet are placed in the drying box, the drying box is taken out immediately after being dried for half an hour, the control sheet is pasted in the scanning head, and the drying agent is fixed on the position where the light beam is not shielded by using 704 solid glue. The scanning head is immediately covered and is ensured to be in a fixed position for about 2 hours without rotating. Or before the scanning head is assembled, a heating plate is arranged on the inner wall for heating control under low temperature.

When the method for installing and placing the drying agent and the control sheet is adopted, the problem of condensation inside the scanning head can be solved, but the method has the following defects:

1. too long and cumbersome time to mount the scanning head

Before the scanning head is covered, a large part of drying agent and the control sheet are fixed, and the period can not be interrupted, otherwise, the dehumidification effect of the drying agent can not be ensured. Meanwhile, the solid glue for fixing the drying agent is longer in curing time, and the assembling time is prolonged.

2. Has limited service life and needs to be replaced regularly

Because the mechanical structure of scanning head can't guarantee hundreds of airtight, so have the steam infiltration to enter, after the absorptive steam of drier reached certain degree, just can't continue to absorb steam, still can lead to the dewfall for a long time to it is essential to change the drier regularly.

3. Heating sheet attachment

Because there are reasons such as processing defect in the scanning head inner wall, the heating plate can have the inhomogeneous condition of laminating, if inhomogeneous too big, can lead to the heating plate to damage, unable work.

Disclosure of Invention

The technical scheme is as follows: in order to prevent the interior of the radar scanning head from dewing, a dewing point control device is arranged in the interior of the scanning head of the three-dimensional scanning type laser radar, and the internal dewing phenomenon is prevented by changing the temperature and the humidity of the internal environment. And when the scanner operates under the low-temperature condition, the performance is reduced, and the rotating precision cannot be ensured, the invention provides a three-dimensional scanning type wind lidar scanning head junction point control device, in particular to a three-dimensional scanning type wind lidar scanning head junction point control device

The controller comprises a controller mainboard, a thermistor, a humidity sensor and a pressure sensor; the controller mainboard is used for collecting signals measured with the outside and processing the signals by an algorithm; the humidity sensor is used for acquiring a humidity signal, and is electrically connected with the controller mainboard and used for signal transmission; the pressure sensor is used for collecting pressure signals, and is electrically connected with the controller mainboard and used for signal transmission; the thermistor is arranged in a multi-path resistor structure and used for measuring the temperatures of a plurality of temperature points, and is electrically connected with the controller mainboard and used for signal transmission.

As an improvement, the device also comprises a dehumidifier, a fan and a TEC temperature controller; the dehumidifier is connected with the controller mainboard and used for receiving signals and carrying out internal water vapor transportation treatment; the TEC temperature controller is arranged on the surface of the fan and is used for being matched with the fan to provide refrigeration or heating treatment; and the fan is connected with the controller mainboard and used for receiving the signals and then carrying out air supply processing.

As an improvement, when the controller main board carries out algorithm processing, the moisture of the dew point under the environmental temperature in the scanning head is obtained by collecting a plurality of groups of temperature values in the scanning head, and then a working signal is sent out.

As an improvement, when the algorithm is processed, the following formula (1) is adopted:

in the formula (1), the value of Td is obtained by comparing the temperature of the window mirror with the temperature of the inner wall of the scanning head, and taking two values with small temperature as calculated values, the value of T represents the ambient temperature, and a and b are correction numerical parameters.

As an improvement, when the Td meets the requirement (0, T), the moisture of the condensation point is obtained according to the formula (1), then the moisture is compared with the current moisture, a difference value is calculated, and if the moisture difference value is smaller than a refrigeration maximum threshold value, a signal for starting a fan and enabling the TEC temperature controller to be in a refrigeration state is sent;

if the fan and the temperature control TEC are started for a long time, the humidity difference value is still smaller than the highest refrigerating threshold value, and when the humidity difference value is close to the lowest refrigerating threshold value, the dehumidifier is started to dehumidify the internal humidity, and the internal humidity processing signal is directly reduced.

As an improvement, when the Td is less than 0, the calculation of the junction point is not carried out by the formula (1), and if the Td temperature is detected to be less than the lowest heating threshold value, the signal processing that the fan is started and the TEC temperature controller is in the heating state is sent out; and if the temperature Td is detected to be lower than the highest heating threshold, sending a signal for stopping the fan and processing the signal that the TEC temperature controller is in the heating state.

As an improvement, when Td is greater than T, the junction point calculation is not performed by the formula (1), and at this time, signals of the off states of the fan, the TEC temperature controller, and the dehumidifier are sent.

In addition, the method for controlling the dew point of the three-dimensional scanning type wind lidar scanning head is also provided, and the specific steps are

(1) Preparation work

Electrifying the whole control device, collecting signals by the humidity sensor and the pressure sensor, and reading signals including but not limited to a plurality of paths of temperature values, humidity values and pressure values;

(2) data processing and sending out working signal

Comparing the temperature of the window mirror with the temperature of the inner wall of the scanning head, taking two values with small temperatures as Td calculated values to obtain the moisture of the condensation point, comparing the moisture with the current moisture value in a mode that the Td satisfies three intervals of being less than 0, being greater than T and being (0, T), and sending out corresponding working signals;

(3) end of work

And after the fan, the TEC temperature controller and the dehumidifier receive the corresponding signals, working until the end signal is received to complete the working cycle.

As an improvement, in the step (2), when Td meets (0, T), the dew point humidity is obtained according to the formula (1), and then compared with the current humidity, a difference value is calculated, and if the humidity difference value is smaller than a refrigeration maximum threshold value, a signal for starting a fan and enabling a TEC temperature controller to be in a refrigeration state is sent;

if the fan and the temperature control TEC are started for a long time, the humidity difference value is still smaller than the highest refrigerating threshold value, and when the humidity difference value is close to the lowest refrigerating threshold value, the dehumidifier is started to dehumidify the internal humidity, and the internal humidity processing signal is directly reduced.

As a modification, in the step (2),

when the Td is less than 0, the calculation of the condensation point is not carried out according to the formula (1), and if the Td temperature is detected to be less than the lowest heating threshold value, the signal processing that the fan is started and the TEC temperature controller is in the heating state is sent out; if the temperature Td is detected to be lower than the highest heating threshold, sending a signal for stopping the fan and processing the TEC temperature controller in a heating state;

and when the Td is larger than T, calculating the condensation point without the formula (1), and sending signals of the closed states of the fan, the TEC temperature controller and the dehumidifier.

Has the advantages that: compared with the conventional method, the device and the method provided by the invention have the following advantages:

(1) the dew point control device is simple and quick to mount, can be directly fixed by a screw, and does not need long-time adhesion and complex procedures like a drying agent.

(2) After adding the dew point humidity algorithm, to the control logic under the different temperatures, through calculating dew point humidity and making the contrast with current inside humidity, realize the control of dew point, can effectually avoid the too much problem of control of dehumidifier, the life-span of having promoted the dehumidifier, increased the environment temperature control mode that the fan adds the TEC temperature controller simultaneously, provide cold wind and hot-blast, and utilize the air cycle mode to carry out the control by temperature change to the inside air of scanning head, can effectively maintain inside holistic ambient temperature, rather than the temperature at single position.

Drawings

Fig. 1 is a schematic structural diagram of a lidar scanning head of the present invention, with a left side view and a right side view.

FIG. 2 is a schematic diagram of the scanning head dew point control device of the present invention.

Fig. 3 is a flowchart of a method of controlling a junction point control device in embodiment 1 of the present invention.

Wherein in FIG. 3: hum _ com represents the current dew point humidity value and Hum _ value represents the measured humidity value.

Detailed Description

The following examples are given to further illustrate the embodiments of the present invention. The following examples are intended to illustrate the invention but are not intended to limit the scope of the invention.

The three-dimensional scanning type wind measuring laser radar comprises a scanning head, two transmission mechanisms, a window mirror and a rotary table, wherein the two transmission mechanisms are an X-axis movement mechanism and a Z-axis movement mechanism, and comprise a scanning motor and a rear cover plate which are independent respectively, namely a Z-axis scanning motor, an X-axis scanning motor, a Z-axis rear cover plate and an X-axis rear cover plate. The back cover plates of the two shafts are fixed by fixing parts such as screws, and sealing rubber strips are arranged on the peripheries of the back cover plates and used for preventing the scanning head from being water. The detection light passes through the inside specular reflection of scanning head, realizes that the wind speed of the different angles of radar is surveyed, and dew point controlling means installs inside the revolving stage, because the space of revolving stage is enough big, can not shelter from the detection light path production.

The device for controlling the dew point of the scanning head of the three-dimensional scanning type wind measuring laser radar comprises a controller mainboard, a thermistor, a humidity sensor and a pressure sensor; the controller mainboard is used for collecting signals measured with the outside and processing the signals by an algorithm; the humidity sensor is used for acquiring a humidity signal, and is electrically connected with the controller mainboard and used for signal transmission; the pressure sensor is used for collecting pressure signals, and is electrically connected with the controller mainboard and used for signal transmission; the thermistor is arranged in a multi-path resistor structure and used for measuring the temperatures of a plurality of temperature points, and is electrically connected with the controller mainboard and used for signal transmission.

Also comprises a dehumidifier, a fan and a TEC temperature controller; the dehumidifier is connected with the controller mainboard and used for receiving signals and carrying out internal water vapor transportation treatment; the TEC temperature controller is arranged on the surface of the fan and is used for being matched with the fan to provide refrigeration or heating treatment; and the fan is connected with the controller mainboard and used for receiving the signals and then carrying out air supply processing.

When the controller main board carries out algorithm processing, the moisture of the dew point under the environmental temperature in the scanning head is obtained by collecting a plurality of groups of temperature values in the scanning head, and then a working signal is sent out.

When algorithm processing is carried out, the following formula (1) is adopted:

in the formula (1), the value of Td is obtained by comparing the temperature of the window mirror with the temperature of the inner wall of the scanning head, and taking two values with small temperature as calculated values, the value of T represents the ambient temperature, and a and b are correction numerical parameters.

When Td meets (0, T), obtaining dew point humidity according to a formula (1), comparing with the current humidity, calculating a difference value, and if the humidity difference value is smaller than a refrigeration maximum threshold value, sending a signal for starting a fan and enabling a TEC temperature controller to be in a refrigeration state;

if the fan and the temperature control TEC are started for a long time, the humidity difference value is still smaller than the highest refrigerating threshold value, and when the humidity difference value is close to the lowest refrigerating threshold value, the dehumidifier is started to dehumidify the internal humidity, and the internal humidity processing signal is directly reduced.

When the Td is less than 0, the calculation of the condensation point is not carried out according to the formula (1), and if the Td temperature is detected to be less than the lowest heating threshold value, the signal processing that the fan is started and the TEC temperature controller is in the heating state is sent out; and if the temperature Td is detected to be lower than the highest heating threshold, sending a signal for stopping the fan and processing the signal that the TEC temperature controller is in the heating state.

And when the Td is larger than T, calculating the condensation point without the formula (1), and sending signals of the closed states of the fan, the TEC temperature controller and the dehumidifier.

The method of controlling the dew point of the scanning head of three-dimensional scanning wind measuring laser radar includes the following steps

(1) Preparation work

Electrifying the whole control device, collecting signals by the humidity sensor and the pressure sensor, and reading signals including but not limited to a plurality of paths of temperature values, humidity values and pressure values;

(2) data processing and sending out working signal

Comparing the temperature of the window mirror with the temperature of the inner wall of the scanning head, taking two values with small temperatures as Td calculated values to obtain the moisture of the condensation point, comparing the moisture with the current moisture value in a mode that the Td satisfies three intervals of being less than 0, being greater than T and being (0, T), and sending out corresponding working signals;

(3) end of work

And after the fan, the TEC temperature controller and the dehumidifier receive the corresponding signals, working until the end signal is received to complete the working cycle.

The method is characterized in that: in the step (2), when Td meets the requirement (0, T), obtaining the dew point humidity according to the formula (1), comparing the dew point humidity with the current humidity, calculating a difference value, and if the humidity difference value is smaller than a refrigeration maximum threshold value, sending a signal for starting a fan and enabling a TEC temperature controller to be in a refrigeration state;

if the fan and the temperature control TEC are started for a long time, the humidity difference value is still smaller than the highest refrigerating threshold value, and when the humidity difference value is close to the lowest refrigerating threshold value, the dehumidifier is started to dehumidify the internal humidity, and the internal humidity processing signal is directly reduced.

In the step (2),

when the Td is less than 0, the calculation of the condensation point is not carried out according to the formula (1), and if the Td temperature is detected to be less than the lowest heating threshold value, the signal processing that the fan is started and the TEC temperature controller is in the heating state is sent out; if the temperature Td is detected to be lower than the highest heating threshold, sending a signal for stopping the fan and processing the TEC temperature controller in a heating state;

and when the Td is larger than T, calculating the condensation point without the formula (1), and sending signals of the closed states of the fan, the TEC temperature controller and the dehumidifier.

Example 1

As an embodiment of the present invention, a humidity sensor and a pressure sensor are selected as BMP388 and HDC1080, and are optionally mounted on the controller motherboard for measuring humidity and pressure.

The controller mainboard is used for peripheral control, signal acquisition and algorithm processing, and obtains an optimal control mode after algorithm processing according to the information of the external sensor. Wherein the external control comprises the control of a dehumidifier, a fan and a TEC temperature controller.

The dehumidifier is used for carrying work of internal water vapor, and the TEC temperature controller is selectively attached to the radiating fins of the fan, so that cold air and hot air are supplied for refrigeration and heating.

The thermistor is selected to be a three-way thermistor in the embodiment and is used for measuring the temperature of each temperature point which is respectively positioned at the periphery of the window mirror, the inner wall of the scanning head and the non-light path space in the scanning head. The collection of temperatures provides an effective support for control of the junction point.

In another embodiment of the present invention, in formula 1, a is set to 17.27, b is set to 237.7, the highest cooling threshold is set to 8-10%, the lowest cooling threshold is set to 3-5%, the highest heating threshold is set to-5 ℃, and the lowest heating threshold is set to-10 ℃, at this time, for three different temperature intervals, the control signals are as follows:

1、Td＜0

in this interval, the dew point calculation is not performed by the formula of the dew point. In the current state, when the Td temperature is detected to be less than-10 ℃, the fan is started and the temperature-controlled TEC is in a heating state. Because the stability of the scanning head can be reduced under the low-temperature condition, the internal temperature is increased through the heating of hot air, the working stability of the scanning head is improved, when the temperature reaches minus 5 ℃, the heating is stopped, and the fan and the temperature control TEC are turned off.

2、0＜Td＜T

In the interval, after the dew point humidity is calculated through a dew point formula, the difference value between the current humidity and the dew point humidity is calculated, if the humidity difference value is less than 10%, a fan is immediately started, the temperature control TEC is in a refrigeration state, the ambient temperature is immediately reduced, the difference value between Td and T is reduced, and the dew point value is increased.

If the fan and the temperature control TEC are started for a long time, the humidity difference value is still less than 10% and is close to 5%, the dehumidifier is started to dehumidify the internal humidity, and the internal humidity is directly reduced.

Because the dehumidifier has certain life, the dehumidifier can not work for a long time, the control mode effectively reduces the using time of the dehumidifier, and the service life of the dehumidifier is ensured.

3、Td>T

In the interval, the interior of the scanning head can not form a condensation phenomenon, and the fan, the temperature control TEC and the dehumidifier are all in a closed state.

The device reduces the difficulty of assembling the scanning head and shortens the installation time. Through inside air cycle, the effectual refrigeration and the heating that has realized inside ambient temperature for the inside temperature of whole scanning head is all comparatively balanced, has guaranteed the performance of scanning head operation.

Through the monitoring of various sensors, the principle of the condensation and the humidity threshold value of the condensation are combined, different control requirements are met, and the fact that the condensation does not exist in the scanning head is guaranteed.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.