阅读说明：本技术 一种太赫兹成像仪探测器阵列校准装置 (Terahertz imager detector array calibrating device ) 是由 胡广骁 胡睿佶 朱雨 高广东 缪玮杰 高炳西 冯辉 于 2020-11-20 设计创作，主要内容包括：本发明公开了一种太赫兹成像仪探测器阵列校准装置,属于太赫兹成像技术领域,包括转动组件、开关控制组件、测试校准组件、触发开关组件,所述开关控制组件与所述转动组件连接,所述触发开关组件与太赫兹成像仪电连接,通过调节所述开关控制组件的位置使所述触发开关组件开闭,控制切换太赫兹成像仪的工作模式与转动组件的运动过程,所述测试校准组件与所述转动组件连接。本发明通过电机、支架、限位开关等组件的巧妙设置,能够方便地对太赫兹成像仪探测器阵列进行校准,操作更加方便；并且采用太赫兹成像仪内部校准的方式,摆脱外部辅助设备,同时大大降低对均匀太赫兹视场环境的依赖,填补了对太赫兹成像仪探测器阵列校准方面的空白。(The invention discloses a terahertz imager detector array calibration device, which belongs to the technical field of terahertz imaging and comprises a rotating assembly, a switch control assembly, a test calibration assembly and a trigger switch assembly, wherein the switch control assembly is connected with the rotating assembly, the trigger switch assembly is electrically connected with a terahertz imager, the trigger switch assembly is opened and closed by adjusting the position of the switch control assembly, the working mode of the terahertz imager and the movement process of the rotating assembly are controlled and switched, and the test calibration assembly is connected with the rotating assembly. According to the terahertz imager detector array calibration device, the components such as the motor, the bracket and the limit switch are ingeniously arranged, so that the terahertz imager detector array can be conveniently calibrated, and the operation is more convenient; and the internal calibration mode of the terahertz imager is adopted, external auxiliary equipment is eliminated, the dependence on a uniform terahertz field of view environment is greatly reduced, and the blank in the aspect of calibrating the detector array of the terahertz imager is filled.)

1. The utility model provides a terahertz imager detector array calibrating device which characterized in that: including runner assembly, on-off control subassembly, test calibration subassembly, trigger switch subassembly, on-off control subassembly with the runner assembly is connected, the trigger switch subassembly is connected with terahertz imager electricity, through adjusting the position of on-off control subassembly makes the switching of trigger switch subassembly, the control switches terahertz imager's mode and runner assembly's motion process, the test calibration subassembly with the runner assembly is connected.

2. The terahertz imager detector array calibration device of claim 1, wherein: the switch control assembly comprises a first switch separation blade and a second switch separation blade, and the first switch separation blade and the second switch separation blade rotate to different positions along with the rotating assembly to control the working mode of the terahertz imager and the movement process of the rotating assembly.

3. The terahertz imager detector array calibration device of claim 2, wherein: the trigger switch assembly comprises a first limit switch and a second limit switch, when the first limit switch is shielded by the first switch separation blade, the rotating assembly is controlled to stop rotating, the terahertz imager is triggered to acquire calibration data, and when the second limit switch is shielded by the second switch separation blade, the rotating assembly is controlled to stop rotating, and the terahertz imager is triggered to acquire image data.

4. The terahertz imager detector array calibration device of claim 3, wherein: the test calibration assembly comprises a terahertz wave absorbing material plate and a support, wherein the terahertz wave absorbing material plate is arranged at one end of the support.

5. The terahertz imager detector array calibration device of claim 4, wherein: the test calibration assembly further comprises a detector baffle, and the terahertz wave-absorbing material plate is connected with the support through the detector baffle.

6. The terahertz imager detector array calibration device of claim 5, wherein: when the terahertz imager collects calibration data, the detector baffle completely shields the detector array of the terahertz imager.

7. The terahertz imager detector array calibration device of claim 6, wherein: the rotating assembly comprises a rotating shaft and a motor, the other end of the support is connected with the rotating shaft, and the motor is connected with the end of the rotating shaft through a coupler and drives the rotating shaft to rotate.

8. The terahertz imager detector array calibration apparatus of claim 7, wherein: the first switch separation blade and the second switch separation blade are arranged on the rotating shaft.

9. The terahertz imager detector array calibration apparatus of claim 8, wherein: the motor is a stepping motor or a servo motor.

10. The terahertz imager detector array calibration apparatus of claim 9, wherein: the acceleration and deceleration processes of the motor are driven by Logistic function pulses.

Technical Field

The invention relates to the technical field of terahertz imaging, in particular to a terahertz imager detector array calibration device.

Background

The passive terahertz imager is widely applied to the field of security inspection and protection in public places such as subways, railway stations and large-scale exhibitions. The method is limited by the technical development and production cost of terahertz detectors, and at present, passive terahertz imagers mostly use unit detectors which are linearly spliced into a detector array, and a one-dimensional scanning mode is added to obtain full-field images of detected targets such as human bodies.

The detector output voltage can be generally expressed in the form of y ═ kx + b, where y is the detector output voltage, k is the response coefficient, x is the input terahertz radiation power, and b is the detector background noise. For the existing terahertz waveband detector, the k value difference between different detectors is not large and is stable, but the b value difference is large, the drift is large along with time, and the imaging effect is greatly influenced.

In order to reduce the influence, a background plate with relatively uniform terahertz radiation can be placed in the field of view of the terahertz imager, or a region with relatively uniform radiation in the field of view of the terahertz imager is searched, calibration data is obtained, and the relative b values of different detectors in the detector array are calculated. For the first method, external equipment is needed for assistance, and the equipment complexity is increased; for the second method, the field of view of the terahertz imager needs to be uniform, and the use environment is limited. Obviously, the two methods are not beneficial to external field laying and using of the terahertz imager.

For visible light and infrared light imagers, mechanical shutters are often used to calibrate the array detector. However, for terahertz imagers, no relevant literature is seen to introduce a calibration mode at present. Therefore, a terahertz imager detector array calibration device is provided.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: how to solve the problem of calibrating the detector array of the terahertz imager, a terahertz imager detector array calibrating device is provided, and the terahertz imager detector array calibrating device can also be called a mechanical shutter of the terahertz imager.

The terahertz imager comprises a rotating assembly, a switch control assembly, a test calibration assembly and a trigger switch assembly, wherein the switch control assembly is connected with the rotating assembly, the trigger switch assembly is electrically connected with the terahertz imager, the trigger switch assembly is opened and closed by adjusting the position of the switch control assembly, the working mode of the terahertz imager and the movement process of the rotating assembly are controlled and switched, and the test calibration assembly is connected with the rotating assembly.

Furthermore, the switch control assembly comprises a first switch separation blade and a second switch separation blade, and the first switch separation blade and the second switch separation blade rotate to different positions along with the rotating assembly to control the working mode of the terahertz imager and the movement process of the rotating assembly.

Furthermore, the trigger switch subassembly includes first limit switch and second limit switch, first limit switch by when first switch separation blade shelters from, control the runner assembly stop rotating, trigger terahertz imager collection calibration data simultaneously, second limit switch by when second switch separation blade shelters from, control the runner assembly stop rotating, trigger terahertz imager collection image data simultaneously.

Furthermore, the test calibration assembly comprises a terahertz wave-absorbing material plate and a support, wherein the terahertz wave-absorbing material plate is arranged at one end of the support.

Furthermore, the test calibration assembly further comprises a detector baffle plate, and the terahertz wave-absorbing material plate is connected with the support through the detector baffle plate.

Furthermore, the detector baffle completely shields the detector array of the terahertz imager when the terahertz imager collects the calibration data.

Furthermore, the rotating assembly comprises a rotating shaft and a motor, the other end of the support is connected with the rotating shaft, and the motor is connected with the end of the rotating shaft through a coupler and drives the rotating shaft to rotate.

Furthermore, the first switch blocking piece and the second switch blocking piece are arranged on the rotating shaft.

Further, the motor is a stepping motor or a servo motor.

Furthermore, the acceleration and deceleration processes of the motor are driven by adopting Logistic function pulses.

Compared with the prior art, the invention has the following advantages: according to the calibration device for the detector array of the terahertz imager, the detector array of the terahertz imager can be conveniently calibrated through the ingenious arrangement of the motor, the bracket, the limit switch and other components, so that the operation is more convenient; and the internal calibration mode of the terahertz imager is adopted, external auxiliary equipment is eliminated, the dependence on a uniform terahertz field of view environment is greatly reduced, the blank in the aspect of calibrating the detector array of the terahertz imager is filled, and the terahertz imager is worthy of being popularized and used.

Drawings

FIG. 1 is a schematic diagram of a calibration data acquisition bit of a calibration device according to a second embodiment of the present invention;

FIG. 2 is a diagram illustrating an image data collection bit of a calibration device according to a second embodiment of the present invention;

FIG. 3 is a top view of a second embodiment of the present invention;

FIG. 4 is a timing diagram of a rotation speed of the calibration transpose motor according to the second embodiment of the present invention;

fig. 5 is a timing chart of the movement angle of the motor of the calibration device according to the second embodiment of the present invention.

Detailed Description

The following examples are given for the detailed implementation and specific operation of the present invention, but the scope of the present invention is not limited to the following examples.

The embodiment provides a technical scheme: the utility model provides a terahertz imager detector array calibrating device now, includes runner assembly, switch control subassembly, test calibration subassembly, trigger switch subassembly, the switch control subassembly with the runner assembly is connected, the trigger switch subassembly is connected with terahertz imager electricity now, through adjusting the position of switch control subassembly makes the switch component switching, the control switches terahertz imager's mode of operation and runner assembly's motion process now, the test calibration subassembly with the runner assembly is connected.

Furthermore, the switch control assembly comprises a first switch separation blade and a second switch separation blade, and the first switch separation blade and the second switch separation blade rotate to different positions along with the rotating assembly to control the working mode of the terahertz imager and the movement process of the rotating assembly.

Furthermore, the trigger switch subassembly includes first limit switch and second limit switch, first limit switch by when first switch separation blade shelters from, control the runner assembly stop rotating, trigger terahertz imager collection calibration data simultaneously, second limit switch by when second switch separation blade shelters from, control the runner assembly stop rotating, trigger terahertz imager collection image data simultaneously.

Furthermore, the test calibration assembly comprises a terahertz wave-absorbing material plate and a support, wherein the terahertz wave-absorbing material plate is arranged at one end of the support.

Furthermore, the test calibration assembly further comprises a detector baffle plate, and the terahertz wave-absorbing material plate is connected with the support through the detector baffle plate.

Furthermore, the detector baffle completely shields the detector array of the terahertz imager when the terahertz imager collects the calibration data.

Furthermore, the rotating assembly comprises a rotating shaft and a motor, the other end of the support is connected with the rotating shaft, and the motor is connected with the end of the rotating shaft through a coupler and drives the rotating shaft to rotate.

Furthermore, the first switch blocking piece and the second switch blocking piece are arranged on the rotating shaft.

Further, the motor is a stepping motor or a servo motor.

Furthermore, the acceleration and deceleration processes of the motor are driven by adopting Logistic function pulses.

Further, when the imager is in the image data acquisition mode, the motor is stationary, the detector baffle does not shield the detector array, the image data acquisition bit limit switch is in the triggered state, and the calibration data acquisition bit limit switch is in the non-triggered state. After the imager sends the calibration instruction, the motor starts, firstly drives the acceleration motion by the acceleration Logistic function pulse, then drives the deceleration motion by the deceleration Logistic function pulse until the image data acquisition position limit photoelectric switch is in the non-trigger state, and the calibration data acquisition position limit switch is in the trigger state, the motor stops rotating, at this moment, the detector baffle completely shelters the detector array, and the imager collects the calibration data for a certain time. After the calibration data acquisition duration is up, the motor is started, the steering direction is reversed, firstly, acceleration motion is driven by acceleration Logistic function pulses, then, deceleration motion is driven by deceleration Logistic function pulses until the image data acquisition position limiting photoelectric switch is in a trigger state, the calibration data acquisition position limiting switch is in a non-trigger state, the motor stops rotating, the imager recovers to an image data acquisition mode, and one calibration period is completed.

Example two

As shown in fig. 1 to 5, this embodiment provides a terahertz imager detector array calibration device, including a detector array 1, a terahertz wave-absorbing material plate 2, a detector baffle 3, a support 4, a rotating shaft 5, a first switch baffle 6, a first limit switch 7, a second switch baffle 8, a second limit switch 9, a mounting seat 10, a motor 11, and a coupler 12.

The mounting seat 10 is fixedly mounted at a designated position on one side of the detector array 1 and used for fixing the positions of the first limit switch 7 and the second limit switch 9. The terahertz wave-absorbing material plate 2 is made of terahertz wave-absorbing materials, is connected with the support 4 through the detector baffle 3, and is adhered to the detector baffle 3 through the terahertz wave-absorbing material plate 2. The terahertz wave-absorbing material plate is characterized in that the detector baffle 3 is used for shielding the detector array 1 (the detector baffle 3 mainly plays a role in shielding external terahertz radiation, eliminates the influence of kx in kx + b and further determines a relative b value), the support 4 is used for supporting the detector baffle 3 and the terahertz wave-absorbing material plate 2, and the terahertz wave-absorbing material plate 2 is used for providing more consistent radiation input for each detector in the detector array 1, so that subsequent calibration work is facilitated. The upper portion of support 4 with pivot 5 is connected, pivot 5 passes through the output connection of shaft coupling 12 and motor 11, first switch separation blade 6 second switch separation blade 8 with pivot 5 is fixed pivot 5 drives support 4 pivoted in-process, first switch separation blade 6 second switch separation blade 8 is along with rotating to shelter from different limit switch in succession, trigger terahertz imager's different orders, accomplish calibration data and image data's collection work. The first limit switch 7 and the second limit switch 9 are electrically connected with the terahertz imager.

Fig. 1 is a schematic diagram of a calibration data acquisition bit of the calibration device, the second switch separation blade 8 rotates along with the rotating shaft 5 to a position where the second limit switch 9 is shielded, meanwhile, the first switch separation blade 6 does not shield the first switch separation blade 6, the motor 11 stops rotating, a calibration data acquisition command of the terahertz imager is triggered, and after the calibration data acquisition command is received by the terahertz imager signal acquisition card, the calibration data starts to be acquired and uploaded to processing software to calculate the relative b values between different channels.

Fig. 2 is a schematic diagram of an image data acquisition position of the calibration device, after the terahertz imager acquires calibration data for a certain period of time, the motor 11 is controlled to rotate reversely until the first switch blocking piece 6 rotates to block the first limit switch 7, and meanwhile, the second switch blocking piece 8 does not block the second limit switch 9, the motor 11 stops rotating, and an image data acquisition command of the terahertz imager is triggered. After receiving an image data acquisition command, a terahertz imager signal acquisition card starts to acquire image data, uploads the image data to processing software, and processes and displays the image data. Since the relative b values between different channels have been calculated from the calibration data, the original image data y ═ b is known and can be directly subtracted, the processed image data y ═ kx is obtained, the k value difference between different channels is small, and y' can be obtained to be proportional to x, that is, the processed image data is only related to the incident terahertz radiation x, thereby realizing the correction of the detector array.

The calibration data is acquired alternately with the image data to thereby effect calibration of the detector array response.

The acceleration and deceleration processes of the motor 11 adopt Logistic function pulse driving, and the problems of motor step loss, rotation blockage, large mechanical noise and jitter and the like caused by overlarge starting speed and sudden stop in the same pulse frequency driving are solved.

The acceleration curve equation is given by:

wherein, Δ F ═ F_max-F_min，F_minFor the starting frequency of the stepping motor, F_maxIs the maximum pulse frequency; n is the acceleration stage number/2; a is the slope of the function, i.e. the acceleration interval. The motor 11 acceleration process is an acceleration curve composed of a fundamental frequency and a jump frequency (a frequency at which the stepping motor gradually increases at the fundamental frequency).

Correspondingly, the equation of the curve for the deceleration section of the motor 11 can be expressed as follows:

in the middle of the acceleration and deceleration motion process, a constant pulse frequency is set to control the motor to rotate at a constant speed.

Fig. 4 shows an embodiment of the calibration apparatus for the time sequence of the motor rotation speed, and the whole motor motion process includes three processes of (1) rotating the image data acquisition bit to the calibration data acquisition bit, (2) calibrating the data acquisition segment, and (3) rotating the calibration data acquisition bit to the image data acquisition bit. In the process (1), the motor 11 is controlled by an acceleration curve pulse in a static state, the time is taken for about 10ms to accelerate to the maximum rotating speed, then the motor rotates for about 60ms at the maximum rotating speed, finally the motor is controlled to decelerate by a deceleration curve pulse, and after the motor decelerates for about 10ms, the second limit switch 9 is shielded by the second switch baffle sheet 8, so that the motor 11 stops rotating; on the one hand, triggering the imager to acquire calibration data, i.e., process (2), takes about 20 ms. In the process (3), the motor 11 is controlled by an acceleration curve pulse in a static state, the time is taken for about 10ms to accelerate to the maximum rotating speed, then the motor rotates for about 60ms at the maximum rotating speed, finally the motor is controlled to decelerate by the deceleration curve pulse, and after the motor is accelerated for about 10ms, the first limit switch 7 is shielded by the first switch baffle 6, so that the motor 11 stops rotating on one hand, and the imager is triggered to collect image data on the other hand. The angle of rotation of each process motor is given by figure 4.

In summary, the calibration device for the detector array of the terahertz imager in the embodiment can conveniently calibrate the detector array of the terahertz imager by skillfully arranging the motor, the bracket, the limit switch and other components, so that the operation is more convenient; and the internal calibration mode of the terahertz imager is adopted, external auxiliary equipment is eliminated, the dependence on a uniform terahertz field of view environment is greatly reduced, the blank in the aspect of calibrating the detector array of the terahertz imager is filled, and the terahertz imager is worthy of being popularized and used.

Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.