An array-type infrared stealth device based on semiconductor refrigeration chips

Abstract

The present invention discloses an array-type infrared stealth device based on semiconductor refrigeration sheets, which belongs to the field of infrared stealth equipment. The present invention uses a focal plane sensor to scan and obtain the ambient temperature field around the object to be hidden, and then maps it to the semiconductor refrigeration sheet array as the target temperature. The temperature field captured by the infrared focal plane sensor is accurately reflected in the array through the PID control of the semiconductor refrigeration sheet. The present invention can well simulate the infrared characteristics of the environment around the object to be hidden, and has good realism and accuracy. At the same time, the device can be used in scenes where the subject moves. Through the continuous measurement and update of the temperature data by the focal plane sensor, the thermal field pattern of the array subject will also change accordingly, and can be used in scenes of dynamic infrared stealth.

Description

Technical Field

[0001] The present invention belongs to the field of infrared stealth technology, and in particular relates to an array-type infrared stealth device based on semiconductor refrigeration sheets. Background Art

[0002] Infrared stealth technology utilizes an object's control over infrared radiation to reduce or mask the target's signature within the infrared spectrum, making it difficult for infrared sensors to detect. Its basic principles include the following: First, absorption and reflection control. Material selection is crucial for infrared stealth. Certain materials can absorb or reflect infrared radiation, reducing the target's thermal signature. Generally, materials that absorb infrared radiation quickly dissipate heat, making the target's surface temperature less detectable by infrared sensors. Second, temperature control technology works by minimizing the temperature difference between the sample and the environment, reducing the infrared radiation emitted by the device. The lower the effective infrared radiation signal received by the detector, the less noticeable its signature. Temperature control strategies are categorized as passive and active. Passive cooling utilizes ambient temperature differences, while active cooling utilizes various cooling devices. Generally speaking, passive temperature control has higher environmental requirements and is less efficient. Actively acquiring ambient temperature signatures and responding promptly is more efficient than passive control.

[0003] By comprehensively utilizing the above principles, infrared stealth technology can effectively reduce the probability of target detection within the infrared spectrum. It is widely used in military, aerospace, and other fields, improving the target's concealment and survivability. However, achieving efficient and reliable active cooling in infrared stealth technology is a pressing technical challenge. Summary of the Invention

[0004] The purpose of the present invention is to solve the problems in the existing infrared stealth technology that it is difficult to achieve active cooling efficiently and reliably, and to provide an array-type infrared stealth device based on semiconductor refrigeration chips.

[0005] The specific technical solutions adopted in the present invention are as follows:

[0006] An array-type infrared stealth device based on semiconductor refrigeration chips, comprising a semiconductor temperature control unit, an ambient temperature scanning unit, and a communication unit; the ambient temperature scanning unit comprises a focal plane sensor and a first single-chip microcomputer controller; the semiconductor temperature control unit comprises a semiconductor refrigeration chip array, a second single-chip microcomputer controller for temperature control, a temperature sensor, a digital-to-analog conversion chip, and a full-bridge control circuit;

[0007] In the ambient temperature scanning unit, the focal plane sensor scans and obtains the ambient temperature field around the object to be cloaked, and the first single-chip controller performs dimensionality conversion on the obtained ambient temperature field so that the ambient temperature field is mapped one-to-one to the semiconductor refrigeration chip array, with each semiconductor refrigeration chip corresponding to a target temperature value;

[0008] The communication unit is used to send the target temperature value of each semiconductor refrigeration chip obtained by the ambient temperature scanning unit to the semiconductor temperature control unit;

[0009] In the semiconductor temperature control unit, each semiconductor refrigeration chip in the semiconductor refrigeration chip array has its current temperature value detected by one of the temperature sensors, and the digital-to-analog conversion chip converts the current temperature value into a digital signal and sends it to the second single-chip microcomputer controller. After the second single-chip microcomputer controller receives the target temperature value corresponding to each semiconductor refrigeration chip from the communication unit, it controls the temperature of each semiconductor refrigeration chip through a full-bridge control circuit based on the PID control algorithm until the current temperature value of each semiconductor refrigeration chip is adjusted to the target temperature value.

[0010] Preferably, in the semiconductor refrigeration chip array, each semiconductor refrigeration chip is provided with an independent temperature sensor, a digital-to-analog conversion chip and a full-bridge control circuit, but all semiconductor refrigeration chips are divided into one or more second single-chip microcomputer controllers for PID control.

[0011] Preferably, the full-bridge control circuit switches the cooling and heating modes by changing the positive and negative voltage directions of the semiconductor refrigeration plate.

[0012] Preferably, the ambient temperature scanning unit is further provided with a display screen for visually displaying the ambient temperature field after dimension conversion.

[0013] Preferably, in the ambient temperature scanning unit, the effective temperature measurement resolution of the focal plane sensor is higher than the number of semiconductor refrigeration chips in the semiconductor refrigeration chip array. When reducing the dimension of the ambient temperature field directly measured by the focal plane sensor, it is necessary to eliminate the peripheral data of the sensor and take the temperature field data of the central area of ​​the sensor for gridding. The number of grids is the same as the number of semiconductor refrigeration chips in the semiconductor refrigeration chip array. The temperature values ​​measured by multiple pixels contained in each grid are arithmetic averaged as the target temperature value of the corresponding semiconductor refrigeration chip.

[0014] Preferably, the first single-chip microcomputer controller and the second single-chip microcomputer controller both adopt the STM32F103VET6 model.

[0015] Preferably, the focal plane sensor adopts the MLX90640 model.

[0016] Preferably, the semiconductor refrigeration chips in the semiconductor refrigeration chip array adopt the TEC-04905 model.

[0017] Preferably, the digital-to-analog conversion chip is AD7689.

[0018] Preferably, the communication unit adopts 485 communication, and the chip model used is MAX485.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] The present invention uses a focal plane sensor to scan and obtain the ambient temperature field surrounding the object to be concealed, then maps this field to an array of semiconductor refrigeration chips as the target dimension. Through PID control of the semiconductor refrigeration chips, the temperature field captured by the infrared focal plane sensor is accurately reflected in the array. The present invention can effectively simulate the infrared characteristics of the environment surrounding the object to be concealed, with high fidelity and accuracy. Furthermore, the device can be used in scenarios where the subject is moving. As the focal plane sensor continuously measures and updates temperature data, the thermal field pattern of the array subject will also change accordingly, making it suitable for dynamic infrared cloaking scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of the unit composition of an array-type infrared stealth device based on semiconductor refrigeration chips.

[0022] Figure 2 The pin unit diagram of the single chip controller in the embodiment is shown in FIG.

[0023] Figure 3 The full-bridge drive control circuit diagram of the semiconductor refrigeration chip in the embodiment

[0024] Figure 4 The circuit principle of the infrared focal plane sensor control board in the embodiment Figure 1 (Single-chip microcomputer, 1.44-inch display)

[0025] Figure 5 The circuit principle of the infrared focal plane sensor control board in the embodiment Figure 2 (MLX90640 sensor, 485 communication interface)

[0026] Figure 6 It is a working flow chart of the entire array type infrared stealth device in the embodiment. DETAILED DESCRIPTION

[0027] In order to make the above-mentioned objects, features and advantages of the present invention more clearly understood, the specific embodiments of the present invention are described in detail below with reference to the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways than those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below. The technical features in the various embodiments of the present invention can be combined accordingly without conflicting with each other.

[0028] In the description of the present invention, it should be understood that when an element is considered to be "connected" to another element, it can be directly connected to the other element or indirectly connected, that is, there are intermediate elements. On the contrary, when an element is said to be "directly" connected to another element, there are no intermediate elements.

[0029] In the description of the present invention, it should be understood that the terms "first" and "second" are used solely for descriptive purposes and are not to be construed as indicating or implying relative importance or implicitly specifying the number of technical features being described. Therefore, features defined as "first" or "second" may explicitly or implicitly include at least one of such features.

[0030] In a preferred embodiment of the present invention, an array-type infrared stealth device based on a semiconductor refrigeration chip is provided. The device is a thermoelectric array with a semiconductor refrigeration chip as the core, which can realize dynamic infrared stealth. Figure 1 As shown, the array-type infrared stealth device is mainly composed of three circuit functional units: a semiconductor temperature control unit, an ambient temperature scanning unit and a communication unit.

[0031] The semiconductor temperature control unit of the present invention is used to control temperature, either generating heat or cooling. It comprises a semiconductor cooling chip array, a second single-chip controller for temperature control, a temperature sensor, a digital-to-analog conversion chip, and a full-bridge control circuit. The semiconductor cooling chip array consists of a series of independently operating semiconductor cooling chips tightly arranged in an array, which can be considered thermal pixels. The specific array size can be adjusted based on the actual coverage area of ​​the target to be concealed. In this embodiment, the semiconductor cooling chip array has a size of 10×10, with a total of 100 semiconductor cooling chips. The semiconductor cooling chip utilizes the Peltier effect of materials. The principle is that when a certain voltage is applied to the two terminals of the device, the upper and lower surfaces of the device generate heat on one side and cool on the other. When the voltage polarity is switched, the heating and cooling surfaces switch sides. Therefore, this characteristic of the semiconductor cooling chips can be used to control the temperature of the array surface in real time, thereby overcoming the traditional infrared stealth method of simply cooling the surface and enriching the target's application scenarios. The temperature control portion of the semiconductor refrigeration chip array is a feedback control system composed of a single-chip microcomputer controller, a temperature sensor, a digital-to-analog conversion chip, and a full-bridge control circuit. The temperature control strategy in the single-chip microcomputer controller uses the classic proportional-integral-differential (PID) algorithm. Furthermore, each semiconductor refrigeration chip in the semiconductor refrigeration chip array is equipped with an independent temperature sensor, digital-to-analog conversion chip, and full-bridge control circuit. However, all semiconductor refrigeration chips can be evenly distributed to one or more single-chip microcomputer controllers for PID control, meaning that one single-chip microcomputer controller can simultaneously control multiple semiconductor refrigeration chips. In this embodiment, due to the large number of semiconductor refrigeration chips, the number of pins on a single single-chip microcontroller is insufficient to simultaneously control so many semiconductor refrigeration chip units. Therefore, during the design process, 100 semiconductor refrigeration chips were evenly distributed across four identical single-chip microcomputer controllers. Each single-chip microcomputer controller has the same circuit structure design, so only the control board circuit composed of one single-chip microcomputer controller needs to be described.

[0032] It should be noted that the single-chip microcomputer controller, temperature sensor, digital-to-analog conversion chip, and full-bridge control circuit for achieving temperature control in the semiconductor refrigeration array are all available in the existing technologies and can be implemented. The present invention does not limit the specific selection and circuit form of each. However, in this embodiment, the control board circuit pin unit of the single-chip microcomputer controller for controlling the temperature in the semiconductor refrigeration array is shown in FIG. Figure 2As shown, the circuit elements covered by a single control board circuit are as follows: Single chip microcomputer controller: The selected one is STM32F103VET6 from STMicroelectronics, with 100 pins; the digital-to-analog conversion chip AD7689, with 8 conversion channels and 16-bit resolution; the voltage regulator chip MC1403, which allows an input voltage range of 4.5V-40V and an output value of 2.5V, and is used to provide a 2.5V reference voltage to the digital-to-analog conversion chip. Semiconductor refrigeration chip: Model TEC-04905, rated operating voltage of 5V, and the logarithm of the internal thermoelectric arm is 49. The temperature sensor uses a thermistor sensor. In this embodiment, the driving circuit of the semiconductor refrigeration chip uses a full-bridge control circuit, see Figure 3 As shown, the drive circuit for a semiconductor cooler includes two IR2103 half-bridge control chips and four IRFR3607 N-channel field-effect transistors. When this full-bridge control circuit is in use, the microcontroller outputs two PWM signals: one designated PWM and the other DIR. The number represents the serial number of the cooler. The voltage direction is controlled by both the PWM and DIR signals. When the PWM input is a logic "1" and the DIR input is a logic "0," the positive voltage at the cooler is higher than the negative voltage, and the cooler operates in a cooling mode. When the PWM input is a logic "0" and the DIR input is a logic "1," the negative voltage at the cooler is higher than the positive voltage, and the cooler operates in a heating mode. This full-bridge control method allows the cooler to switch between heating and cooling modes.

[0033] Furthermore, the microcontroller controller implements a "proportional-integral-derivative" algorithm for precise temperature control. In this embodiment, position-based PID control is employed to adjust the system output to achieve the desired target. The three components of a PID controller are proportional (P), integral (I), and differential (D). In specific temperature control, the output of each component is calculated with reference to the current temperature. Proportional (P) Component: The proportional component generates a proportional output based on the current error (the difference between the setpoint and the actual value). In a temperature control system, the setpoint is the desired temperature, while the actual value is the current temperature measured by the sensor. Integral (I) Component: The integral component processes the accumulated error and generates an output that is integrated with time. In temperature control, the integral component can help eliminate persistent deviations over long periods of time, such as temperature fluctuations caused by environmental changes. Derivative (D) Component: The derivative component responds to the rate of change of the error and suppresses system overshoot by generating an output that is the time derivative. In temperature control systems, a derivative controller helps reduce the system's sensitivity to temperature changes and prevents temperature overshoot. The output of the entire position PID controller is the weighted sum of these three parts. By adjusting the weight of each part, the control performance can be optimized. The specific mathematical expression can be written as follows:

[0034]

[0035] In the above formula, u[k] is the temperature output at the kth sampling point, and e[k] is the error at the kth sampling point, that is, the difference between the set temperature and the actual temperature. Kp, Ki, and Kd are the weights for proportional, integral, and differential, respectively.

[0036] The communication unit of the present invention uses 485 communication and a MAX485 chip. When in use, the ambient temperature scanning unit acquires ambient temperature field data and transmits it to the semiconductor temperature control unit via the communication unit. The semiconductor temperature control unit then controls the temperature based on the temperature data from the focal plane infrared sensor, bringing its own surface temperature field close to the ambient temperature field.

[0037] The ambient temperature scanning unit of the present invention includes a focal plane sensor and another single-chip microcomputer controller. Among them, the focal plane sensor first scans and obtains the ambient temperature field around the object to be hidden, and the single-chip microcomputer controller performs dimension conversion on the obtained ambient temperature field, so that the ambient temperature field is mapped one-to-one to the semiconductor refrigeration chip array, and each semiconductor refrigeration chip corresponds to a target temperature value. The single-chip microcomputer controller in the ambient temperature scanning unit is the same model as the single-chip microcomputer controller in the array body, both are STM32F103VET6; and the focal plane sensor used to scan the ambient temperature field is model MLX90640, with a field of view angle of 55*35°. In addition, a 1.44-inch TFT color display can be further configured in this embodiment to display the temperature field characteristics scanned by the focal plane, so as to facilitate the correspondence with the array body. The circuit schematic diagram of the single-chip microcomputer and the display screen in the infrared focal plane sensor control board in this embodiment is as follows. Figure 4 As shown, the circuit schematic diagram of MLX90640 sensor and 485 communication interface is as follows Figure 5 As shown in the figure, the MLX90640 infrared focal plane sensor has an effective temperature measurement resolution of 32×24, meaning it can output 768 valid temperature data points at a time. The array contains 100 condensers. Therefore, when sending temperature information to the array, the data from the outer pixels of the infrared focal plane sensor is removed, and only the temperature data from the central 30×20 pixels is used. This is then mapped to the array using a regional average method for dimensionality reduction. Within the entire 30×20 pixel area, a 3×2 grid is used to form a 10×10 grid. When mapping the target temperature to the array, the arithmetic average of the temperature values ​​sampled from the six pixels in each grid is taken as the target temperature value sent to the target condenser in the array. Simultaneously, this calculated data is sent to a TFT color screen, which displays the data in a similar format to the array: a square imaging area is divided into 100 10×10 squares. The image color is based on thermal imaging standards. Qualitatively, high-temperature areas appear red, and low-temperature areas appear blue.

[0038] Therefore, if Figure 6As shown in the figure, the entire temperature control process can be summarized as follows: (1) Ambient temperature field sampling: After power is supplied, the focal plane sensor scans and obtains the ambient temperature field around the object to be hidden, and the single-chip microcomputer controller performs dimension conversion on the obtained ambient temperature field matrix (by gridding and averaging to perform downsampling and dimensionality reduction), so that the ambient temperature field matrix is ​​mapped one-to-one to the semiconductor cooling chip array, each semiconductor cooling chip corresponds to a target temperature value, and is transmitted to the semiconductor temperature control unit through 485 communication. (2) Semiconductor cooling chip temperature sampling: The current temperature value of each semiconductor cooling chip is obtained by using a thermistor, but the temperature sensor sampling obtains an analog signal, which needs to be converted into a digital signal by the digital-to-analog conversion chip AD7689 and then transmitted to the single-chip microcomputer controller for processing; (3) Control algorithm implementation: Using the aforementioned position PID control algorithm, after setting the coefficients of the three terms of proportion, integration and differentiation according to the current temperature value of each semiconductor cooling chip (from ADC) and the target temperature value, the temperature of each semiconductor cooling chip is controlled by the full-bridge control circuit based on the position PID control algorithm until the current temperature value of each semiconductor cooling chip is adjusted to the target temperature value. The working mode output of the semiconductor refrigeration chip controls the polarity of the voltage through a full-bridge drive circuit, and the output power is achieved by the microcontroller changing the duty cycle of its output PWM wave.

[0039] In this way, after the simulation of the semiconductor refrigeration array, the semiconductor refrigeration can accurately reflect the temperature captured by the infrared focal plane sensor in the array. Based on the actual measurement of this stealth device, under the capture of the thermal imager, it can be seen that the array body well simulates the infrared characteristics of the surrounding environment with good realism and accuracy. At the same time, the device can be used in scenes where the subject moves. Through the continuous measurement and update of the temperature data by the focal plane sensor, the thermal field pattern of the array body will also change accordingly, which can be used in dynamic infrared stealth scenes.

[0040] The embodiment described above is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Persons skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, any technical solution obtained by equivalent substitution or equivalent transformation falls within the scope of protection of the present invention.

Claims

1. An array-type infrared stealth device based on semiconductor refrigeration chips, characterized in that: It includes a semiconductor temperature control unit, an ambient temperature scanning unit and a communication unit; the ambient temperature scanning unit includes a focal plane sensor and a first single-chip controller; the semiconductor temperature control unit includes a semiconductor refrigeration chip array and a second single-chip controller for temperature control, a temperature sensor, a digital-to-analog conversion chip and a full-bridge control circuit; In the ambient temperature scanning unit, the focal plane sensor scans and obtains the ambient temperature field around the object to be cloaked, and the first single-chip controller performs dimensionality conversion on the obtained ambient temperature field so that the ambient temperature field is mapped one-to-one to the semiconductor refrigeration chip array, with each semiconductor refrigeration chip corresponding to a target temperature value; The communication unit is used to send the target temperature value of each semiconductor refrigeration chip obtained by the ambient temperature scanning unit to the semiconductor temperature control unit; In the semiconductor temperature control unit, each semiconductor refrigeration chip in the semiconductor refrigeration chip array has its current temperature value detected by one of the temperature sensors, and the current temperature value is converted by the digital-to-analog conversion chip and sent to the second single-chip microcomputer controller in the form of a digital signal. After the second single-chip microcomputer controller receives the target temperature value corresponding to each semiconductor refrigeration chip from the communication unit, it controls the temperature of each semiconductor refrigeration chip through a full-bridge control circuit based on a PID control algorithm until the current temperature value of each semiconductor refrigeration chip is adjusted to the target temperature value. In the ambient temperature scanning unit, the effective temperature measurement resolution of the focal plane sensor is higher than the number of semiconductor refrigeration chips in the semiconductor refrigeration chip array. When reducing the dimension of the ambient temperature field directly measured by the focal plane sensor, it is necessary to eliminate the peripheral data of the sensor and take the temperature field data of the central area of ​​the sensor for gridding. The number of grids is the same as the number of semiconductor refrigeration chips in the semiconductor refrigeration chip array. The temperature values ​​measured by multiple pixels contained in each grid are arithmetic averaged as the target temperature value of the corresponding semiconductor refrigeration chip.

2. The array-type infrared stealth device based on semiconductor refrigeration chips according to claim 1, characterized in that: In the semiconductor refrigeration chip array, each semiconductor refrigeration chip is provided with an independent temperature sensor, a digital-to-analog conversion chip and a full-bridge control circuit, but all semiconductor refrigeration chips are divided into one or more second single-chip microcomputer controllers for PID control.

3. The array-type infrared stealth device based on semiconductor refrigeration chips according to claim 1, characterized in that: The full-bridge control circuit switches the cooling and heating modes by changing the positive and negative voltage directions of the semiconductor refrigeration plate.

4. The array-type infrared stealth device based on semiconductor refrigeration chips according to claim 1, characterized in that: The ambient temperature scanning unit is also provided with a display screen for visually displaying the ambient temperature field after dimension conversion.

5. The array-type infrared stealth device based on semiconductor refrigeration chips according to claim 1, characterized in that: The first single-chip microcomputer controller and the second single-chip microcomputer controller both adopt the STM32F103VET6 model.

6. The array-type infrared stealth device based on semiconductor refrigeration chips according to claim 1, characterized in that: The focal plane sensor adopts the MLX90640 model.

7. The array-type infrared stealth device based on semiconductor refrigeration chips according to claim 1, characterized in that: The semiconductor refrigeration chips in the semiconductor refrigeration chip array are of TEC-04905 model.

8. The array-type infrared stealth device based on semiconductor refrigeration chips according to claim 1, characterized in that: The digital-to-analog conversion chip is AD7689.

9. The array-type infrared stealth device based on semiconductor refrigeration chips according to claim 1, characterized in that: The communication unit adopts 485 communication, and the chip model used is MAX485.

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