Passive and wireless simulated sun sensor system and satellite spacecraft

Abstract

The invention relates to a passive and wireless simulation sun sensor system, comprising: an NFC wireless receiving module configured to provide energy for an NFC simulation sun sensor patch and receive digital information of a solar ray angle sent by the NFC simulation sun sensor patch; the NFC simulation sun sensor patch comprises a four-quadrant battery piece which is configured to generate photo-generated current; the I / V conversion circuit is connected with the four-quadrant battery piece and is configured to convert photo-generated current into analog voltage; the microprocessor is connected with the I / V conversion circuit and the NFC antenna and is configured to process analog voltage to generate digital information of a solar ray angle; the NFC chip is connected with an NFC antenna and the microprocessor; and the NFC antenna is configured to send digital information of a solar ray angle to the NFC wireless receiving module, acquire energy from the NFC wireless receiving module and supply the energy to the NFC chip, the I / V conversion circuit and the microprocessor.

Description

Technical Field

[0001] The present invention relates to the field of aerospace technology, and particularly to a passive wireless analog sun sensor system and a satellite spacecraft. Background Art

[0002] In recent years, passive wireless measurement technology has been widely used in the production and life of all walks of life. However, some problems of sensors or circuits themselves have restricted the development of this technology. Among them, the power supply problem of the entire system during the measurement process and the problem that the system cannot be miniaturized due to measurement environment limitations are particularly prominent. For signal measurements in some special environments (such as deep space and deep sea), it is difficult to achieve a stable wired power supply in the actual measurement process, which greatly reduces the application range of the measurement system. Even if active wireless measurement methods (such as Bluetooth, WIFI, Zigbee, etc.) are used, the measurement system still needs to use batteries or energy for power supply, which results in a relatively large volume of the sensor itself and has a great impact on the portability of the entire system.

[0003] The wireless passive measurement system does not require an external power source to drive, and it has two major advantages: one is that it can greatly reduce the volume of the measurement device, enabling the measurement device to more flexibly monitor the space environment that is not easily monitored; the other is that in theory, the wireless passive measurement system can be used indefinitely without considering battery replacement. It is precisely due to these two essential advantages that the wireless passive measurement system can play an irreplaceable role in space environment measurement.

[0004] As an autonomous identification and communication technology, NFC has a working frequency of 13.56 MHz. NFC performs non-contact two-way data communication through radio frequency, thereby achieving fast communication between multiple devices within a short distance. Moreover, not only can data be exchanged between the NFC antenna and the NFC wireless receiving module (system device with NFC function), but more importantly, energy can be generated through electromagnetic induction coupling, enabling it to work in a passive wireless manner without the need for additional complex circuits and input power, nor wired connection. Therefore, in this context, some NFC integrated circuit (IC) manufacturers have launched NFC chips with energy harvesting functions, which can provide energy for industrial measurement devices or wearable devices by interacting with smart device terminals, and can achieve true passive measurement.

[0005] The sun sensor is one of the most commonly used optoelectronic attitude sensors on satellites and can directly measure the vector of the sun in the satellite body coordinate system. Due to the high brightness of the sun, the sun sensor is hardly interfered by other celestial bodies, so the sun sensor is almost used on all satellites. In order to construct a satellite attitude control system with high redundancy and ensure that the satellite can operate normally under various complex or abnormal conditions, it is necessary to install multiple sun sensors at different positions on the satellite.

[0006] Sun sensors are mainly divided into analog sun sensors and digital sun sensors. Most analog sun sensors use photovoltaic cells as optoelectronic detectors. When sunlight irradiates the photovoltaic cell, the magnitude of the output current of the photovoltaic cell satisfies a specific relationship with the vertical component of the incident intensity of the sunlight. The digital sun sensor constructs an optical system based on the principle of pinhole imaging and uses an image sensor as the focal plane detector.

[0007] With the rise and development of microsatellite technology, the requirements for the quality, volume, and power consumption of sun sensors are getting higher and higher, while the traditional wired connection greatly limits the installation layout of sun sensors. Summary of the Invention

[0008] To solve at least some of the above problems in the prior art, the task of the present invention is to provide a passive wireless analog sun sensor system, including:

[0009] An NFC wireless receiving module, which is configured to provide energy to the NFC analog sun sensor patch and receive the digital information of the sun ray angle sent by the NFC analog sun sensor patch; and

[0010] An NFC analog sun sensor patch, which includes:

[0011] A four-quadrant cell, which is configured to generate a photocurrent;

[0012] An I / V conversion circuit, which is connected to the four-quadrant cell and is configured

[0013] To convert the photocurrent into an analog voltage; and

[0014] A microprocessor, which is connected to the I / V conversion circuit and the NFC antenna and is configured to process the analog voltage to generate the digital information of the sun ray angle;

[0015] An NFC chip, which is connected to the NFC antenna and the microprocessor; and an NFC antenna, which is configured to send the digital information of the sun ray angle to the NFC wireless receiving module and obtain energy from the NFC wireless receiving module to supply the NFC chip, the I / V conversion circuit, and the microprocessor.

[0016] Furthermore, it further includes:

[0017] A housing, wherein the I / V conversion circuit, the microprocessor, the NFC chip and the NFC antenna are arranged at the bottom of the housing;

[0018] An optical head end cap, which is arranged at the top of the housing, and a middle part of the optical head end cap has an opening.

[0019] Furthermore, the quadrant cell is arranged between the optical head end cap and the housing, and at least a part of the quadrant cell is exposed at the opening of the optical head end cap;

[0020] The quadrant cell includes four sub-cell pieces, and at least a part of each sub-cell piece is exposed from the opening of the optical head end cap, and there are gaps between the four sub-cell pieces.

[0021] Furthermore, a multi-layer PCB board is arranged at the bottom of the housing, and the I / V conversion circuit, the microprocessor, the NFC chip and the NFC antenna are arranged on the PCB board; and

[0022] The I / V conversion circuit, the microprocessor and the NFC chip are all arranged in the area surrounded by the NFC antenna.

[0023] Furthermore, the I / V conversion circuit is connected between the NFC chip and the microprocessor, and two pins of the microprocessor are connected to the NFC antenna.

[0024] Furthermore, an equivalent inductance value of the NFC antenna is 1.5 to 1.8 μH;

[0025] The NFC antenna is square, with a side length of 2 cm, a line width of 0.6 mm, a line pitch of 0.6 mm, and the number of turns of the coil is 4 turns.

[0026] Furthermore, the I / V conversion circuit includes a current-voltage conversion module and a low-pass filtering module, and the current-voltage conversion module is connected to the quadrant cell;

[0027] The microprocessor includes a CPU, an A / D conversion and a memory, wherein the A / D conversion is used to process an analog voltage to generate digital information of the solar ray angle;

[0028] The NFC chip includes an energy management module and a storage module, wherein the energy management module supplies power to the microprocessor and the I / V conversion circuit.

[0029] The present invention further provides a satellite spacecraft, which includes a passive wireless analog sun sensor system.

[0030] Furthermore, it further includes:

[0031] A satellite cabin;

[0032] A solar panel, which is arranged on one side of the satellite cabin.

[0033] Furthermore, the NFC wireless receiving module is arranged outside the satellite cabin; and

[0034] A plurality of NFC analog sun sensor patches are arranged outside the satellite cabin and on the solar panel, and the distance between the NFC wireless receiving module and the plurality of NFC analog sun sensor patches is less than 1 meter.

[0035] The present invention has at least the following beneficial effects:

[0036] The analog sun sensor system of the present invention is composed of NFC analog sun sensor patches and an NFC wireless receiving module. The NFC wireless receiving module transmits energy to the NFC analog sun sensor patches through electromagnetic induction, and the NFC analog sun sensor patches transmit the digital information of the sun light angle to the NFC wireless receiving module in a wireless manner. The signal is finally transmitted to the satellite integrated electronics. Thus, the analog sun sensor system realizes the passive wireless transmission of signals and energy, meeting the requirement of flexible placement of the analog sun sensor at multiple positions; the system utilizes the passive wireless energy transmission of NFC and does not require battery replacement.

[0037] The analog sun sensor system of the present invention utilizes the passive wireless energy transmission of NFC, provides an application device for signal collection and processing of the analog sun sensor, and has the advantages of high integration, small volume, and light weight. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to further clarify the above and other advantages and features of the embodiments of the present invention, a more specific description of the embodiments of the present invention will be presented with reference to the accompanying drawings. It can be understood that these drawings only depict typical embodiments of the present invention and will not be considered as limiting its scope. In the drawings, for clarity, the same or corresponding components will be denoted by the same or similar reference numerals.

[0039] Figure 1 Shows a schematic diagram of a satellite spacecraft according to an embodiment of the present invention;

[0040] Figure 2 Shows a perspective view of an NFC analog sun sensor patch according to an embodiment of the present invention;

[0041] Figure 3 Shows a top view of an NFC analog sun sensor patch according to an embodiment of the present invention;

[0042] Figure 4 Shows a schematic diagram of the bottom of an NFC analog sun sensor patch according to an embodiment of the present invention;

[0043] Figure 5 Shows a schematic diagram of a passive wireless analog sun sensor system according to an embodiment of the present invention;

[0044] Figure 6 Shows an NFC passive wireless circuit diagram according to an embodiment of the present invention; and

[0045] Figure 7 Shows an I / V conversion circuit diagram according to an embodiment of the present invention. Detailed implementation manners

[0046] It should be noted that the components in the respective drawings may be exaggerated for illustration purposes and are not necessarily to scale.

[0047] In the present invention, the embodiments are only intended to illustrate the solutions of the present invention and should not be construed as restrictive.

[0048] In the present invention, unless otherwise specified, the quantifiers "a" and "one" do not exclude the scenario of multiple elements.

[0049] It should also be noted here that in the embodiments of the present invention, for clarity and simplicity, only a part of the components or assemblies may be shown, but those of ordinary skill in the art can understand that, under the teaching of the present invention, the required components or assemblies can be added according to specific scenario needs.

[0050] It should also be noted here that within the scope of the present invention, the terms "same", "equal", "equivalent", etc. do not mean that the two values are absolutely equal, but allow a certain reasonable error, that is, the said terms also cover "substantially the same", "substantially equal", "substantially equivalent".

[0051] It should also be noted here that in the description of the present invention, the orientation or positional relationships indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than explicitly or implicitly indicating that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be construed as a limitation of the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as explicitly or implicitly indicating relative importance.

[0052] In addition, the embodiments of the present invention describe the process steps in a specific order. However, this is only for the convenience of distinguishing each step, rather than limiting the sequence of each step. In different embodiments of the present invention, the sequence of each step can be adjusted according to the adjustment of the process.

[0053] In the present invention, the term "configured" refers to setting the shape, structure, material, and / or function of an object to achieve the desired technical effect. Among them, "configured" includes a variety of alternative technical means to achieve this technical effect, and these technical means become obvious under the teaching of the present invention.

[0054] Figure 1 A schematic diagram of a satellite spacecraft according to an embodiment of the present invention is shown; Figure 2 A perspective view of an NFC analog sun sensor patch according to an embodiment of the present invention is shown; Figure 3 A top view of an NFC analog sun sensor patch according to an embodiment of the present invention is shown; Figure 4 A schematic diagram of the bottom of an NFC analog sun sensor patch according to an embodiment of the present invention is shown; Figure 5 A schematic diagram of a passive wireless analog sun sensor system according to an embodiment of the present invention is shown.

[0055] A passive wireless analog sun sensor system includes an NFC wireless receiving module 10 and an NFC analog sun sensor patch 20. As Figure 1 shown, the satellite spacecraft includes a satellite cabin 31 and a solar panel 32 provided on one side of the satellite cabin. A plurality of NFC analog sun sensor patches 10 are installed on the outside of the satellite cabin 31 and the solar panel 32. Further, 3 NFC analog sun sensor patches 10 are respectively provided at the surface of the solar panel 32, the +X-axis outer panel of the satellite cabin 31, and the +Y-axis outer panel of the satellite cabin 31.

[0056] The NFC wireless receiving module 20 is provided outside the satellite cabin, and the distance between the NFC wireless receiving module 20 and the plurality of NFC analog sun sensor patches is less than 1 meter. Since the communication distance of NFC technology ≤ 1m, the NFC wireless receiving module 20 is installed between the 3 patches.

[0057] The NFC wireless receiving module 20 provides energy for the NFC analog sun sensor patch 10, receives the digital information of the sun ray angle sent by the NFC analog sun sensor patch 10, and transmits it to the satellite integrated electronics of the satellite spacecraft. The satellite integrated electronics calculates according to the digital information of the sun ray angle to obtain the attitude information of the satellite spacecraft. The NFC wireless receiving module 20 transmits energy to the NFC analog sun sensor patch 10 by means of electromagnetic induction.

[0058] The analog sun sensor system of the present invention realizes wireless transmission, provides a good solution for the satellite structure design and attitude control, and has good application prospects.

[0059] As Figures 2 to 4 shown, the NFC analog sun sensor patch includes an NFC antenna 1, an NFC chip 2, a microprocessor (MCU, Microcontroller Unit) 3, an I / V conversion circuit 4, a four-quadrant cell 5, an optical head end cap 6, and a housing 7.

[0060] In one embodiment, the size of the NFC analog sun sensor patch is 25mm×25mm×10mm, and the weight is 30g.

[0061] In one embodiment, the optical head end cap 6 is disposed on the housing 7 and connected by screws. A plurality of threaded holes 8, such as 4, are provided on the optical head end cap 6, and a plurality of threaded holes are also provided at the bottom of the housing 7. In one embodiment, the inner side of the housing 7 is subjected to black anodizing and sandblasting to absorb the interference of surface reflected light. The housing 7 is a cuboid.

[0062] In one embodiment, a window is opened in the middle of the optical head end cap 6, and the inner side of the optical head end cap 6 is subjected to black anodizing and sandblasting to absorb the interference of surface reflected light.

[0063] In one embodiment, the four-quadrant cell 5 is disposed between the optical head end cap 6 and the housing 7, and at least a part of the four-quadrant cell 5 is exposed at the window of the optical head end cap 6. The four-quadrant cell 5 serves as an analog sun sensor.

[0064] In one embodiment, the optical head end cap 6 and the four-quadrant cell 5 are fixedly connected by 4 screws through the threaded holes on the head end cap. In one embodiment, the four-quadrant cell 5 includes 4 sub-cell pieces 51, and an identifier 511 is provided on each sub-cell piece 51 to distinguish the quadrants. There is a gap between the 4 sub-cell pieces 51.

[0065] In one embodiment, at least a part of each sub-cell piece 51 is exposed from the window of the optical head end cap 6.

[0066] In one embodiment, as Figure 3As shown, the NFC antenna 1, NFC chip 2, microprocessor 3, and I / V conversion circuit 4 are disposed at the bottom of the housing 7. In one embodiment, there are 4 layers of PCB boards at the bottom of the housing 7, and the thickness of the PCB board is 1 mm. In one embodiment, the NFC antenna 1, NFC chip 2, microprocessor 3, and I / V conversion circuit 4 are disposed on the PCB board. The NFC antenna 1, NFC chip 2, microprocessor 3, and I / V conversion circuit 4 are all processed by printed circuit board technology.

[0067] In one embodiment, the NFC antenna 1 is square, with a side length of 2 cm, a line width of 0.6 mm, a line pitch of only 0.6 mm, and 4 turns of the coil, and is printed on a 1.2 mm thick glass fiber epoxy copper clad board (FR-4 PCB) in the form of a wire.

[0068] The NFC antenna 1 is used to send digital information of the solar ray angle to the NFC wireless receiving module 20.

[0069] In one embodiment, the NFC chip 2, microprocessor 3, and I / V conversion circuit 4 are all disposed within the area surrounded by the NFC antenna 1.

[0070] In one embodiment, as Figure 4 shown, the I / V conversion circuit 4 is connected between the NFC chip 2 and the microprocessor 3, and two pins of the microprocessor 3 are connected to the NFC antenna 1.

[0071] According to simulation and actual measurement, the equivalent inductance value of the NFC antenna 1 is 1.5 - 1.8 μH, and the ideal equivalent inductance value range of the NFC antenna is 1 - 4 μH, meeting its requirements.

[0072] As Figure 5 shown, the NFC wireless receiving module 20 is connected to the satellite integrated electronics of the satellite spacecraft. The satellite integrated electronics supplies power to the NFC wireless receiving module 20, and the NFC wireless receiving module 20 transmits the received digital information of the solar ray angle to the satellite integrated electronics. The satellite integrated electronics calculates based on the digital information of the solar ray angle to obtain the attitude information of the satellite.

[0073] In one embodiment, the NFC antenna 1 obtains energy through the NFC wireless receiving module 20 of the satellite to supply the NFC chip 2, microprocessor circuit 3, and I / V conversion circuit 4.

[0074] In one embodiment, the operating frequency of the NFC chip 2 is 13.56 MHz, and two of its pins are connected to the square NFC antenna to satisfy information storage and reading. The NFC chip 2 includes an energy management module and a storage module, where the storage module is a static random access memory SRAM. Both ends of the NFC antenna 1 are connected to the NFC chip 2, and a tuning capacitor is connected in parallel between them. The function of the NFC chip 2 is to perform energy management and wireless data relay.

[0075] In one embodiment, the I / V conversion circuit 4 includes a current-voltage conversion module and a low-pass filtering module. The I / V conversion circuit 4 is connected to the analog sun sensor.

[0076] In one embodiment, the microprocessor 3 includes a CPU, an A / D converter (analog-to-digital converter), and a memory Memory. The microprocessor processes the analog voltage (digital voltage signal) through A / D conversion to generate digital information on the angle of the sun's rays.

[0077] In one embodiment, the energy management module of the NFC chip 2 supplies power to the microprocessor 3 and the I / V conversion circuit 4.

[0078] The photocurrent generated by the analog sun sensor is converted into a voltage by the current-voltage conversion module of the I / V conversion circuit 4, and then after being filtered by the low-pass filtering module, an analog voltage is generated. The analog voltage is processed by the A / D conversion of the microprocessor 3 to generate digital information on the angle of the sun's rays. The microprocessor 3 transmits the digital information on the angle of the sun's rays to the NFC chip 2, and the NFC chip 2 sends it to the NFC wireless receiving module 20 through the NFC antenna 1.

[0079] The analog sun sensor is a four-quadrant photovoltaic cell. The four-quadrant detector has been widely used in high-resolution displacement deviation measurement, laser collimation of mechanical systems, tracking control, alignment control, etc., and at the same time has good anti-noise performance. The basic principle of the analog sun sensor is to utilize the cosine characteristic of the photocurrent of the photovoltaic cell:

[0080] I(θ) = I0Scosθ

[0081] Where: I is the generated current, I0 is the responsivity of the photovoltaic cell when the light is incident perpendicularly, that is, the current generated per unit area of the cell, θ is the light incident angle, and S is the illumination area. When the sunlight irradiates the photosensitive plane of the quadrant photovoltaic cell through the window of the optical head end cap 6, light spots will be formed in the four quadrants (counterclockwise as S1, S2, S3, and S4 in sequence), thereby generating corresponding photocurrents. The currents generated by the 4 sub-cells are different. The output current is collected and then converted into a digital quantity through the I / V conversion circuit 4 and the microprocessor 3 for processing and calculation (based on a series of calculations of the current, the incident angle θ and azimuth angle β of the sun are obtained, and the angle deviation between the satellite body coordinate system and the inertial coordinate is obtained, thereby obtaining the satellite attitude information).

[0082] Figure 6 Fig. shows the NFC passive wireless circuit diagram according to an embodiment of the present invention.

[0083] As Figure 6 shown, a 50 pF capacitor is connected in parallel between the NFC chip 2 and the NFC antenna 1. The first pin and the second pin of the NFC chip 2 are connected to the NFC antenna 1 through two wires.

[0084] In the NFC passive circuit, the NFC chip 2 communicates with the microprocessor 3 through I 2 C (inter-integratedcircuit) bus. Further, the third pin and the fourth pin of the NFC chip 2 are connected to the microprocessor 3 through SDA (serial data line) and SCL (serial clock line). Two 4.7 kΩ pull-up resistors 14 are externally connected to the SDA and SCL buses. The purpose is to clamp at a high level and at the same time play a current limiting role. The third pin and the fourth pin of the NFC chip 2 are connected to the first interface and the second interface of the microprocessor 3 through the SDA and SCL buses.

[0085] And I 2 C communication is also divided into hardware I 2 C communication and analog I 2 C communication. There are dedicated hardware I 2 C pins on the microprocessor, and there are corresponding I 2 C driver circuits. Hardware I 2 C can be directly configured by calling internal registers through a program, while software I 2 C can use any GPI / O interface on the microprocessor 3, but it is necessary to control the timing line and the data line to output high and low levels through a program, and the program is relatively cumbersome. Therefore, the efficiency of hardware I 2 C is much higher than that of software-simulated I 2 C, and it is generally more stable. The most important thing is that the power consumption of using hardware I 2 C is lower than that of analog I2 is much smaller, which also meets the low-power requirements of the analog ultra-sensitive patch.

[0086] The microprocessor 3 serves as the I 2 C host device, and the NFC chip 2 serves as the I 2 C slave device. The host device always processes 16 bytes to be read or written for the read and write operations of the slave device. After the start condition, the host device (microprocessor 3) sends an address code (a 7-bit binary number, which can be queried in the chip manual) to the slave device (NFC chip 2) and resets the read / write bit to 0 / 1. The slave device sends an acknowledgment signal (ACK) to confirm. Then the host device starts to read or write data, sending or receiving 8-bit data each time, followed by an ACK inquiry, and finally sending a stop condition to complete a data transfer cycle.

[0087] A wire connection between the fifth pin of the NFC chip 2 and the third interface of the microprocessor 3 is externally connected to a 0Ω resistor. The sixth pin of the NFC chip 2 is connected to the fourth interface of the microprocessor 3. The seventh and eighth pins of the NFC chip 2 are grounded to GND, and a 10μF capacitor is connected between the seventh and eighth pins and GND. The seventh and eighth pins of the NFC chip 2 are also connected to the fifth interface of the microprocessor 3 to facilitate the NFC chip 2 to supply power to the microprocessor 3.

[0088] The NFC system uses an SBW (SPY-BI-WIRE) two-wire download interface, namely the TEST (test) interface 15 and the RST (reset) interface 16. The SBW (SPY-BI-WIRE) two-wire download interface is different from the traditional JTAG (Joint Test Action Group) four-wire program download method. While ensuring that the system program can be normally downloaded to the MCU chip, it reduces the vias in the PCB circuit design and minimizes the circuit design layout area to the greatest extent, which is beneficial to miniaturization design.

[0089] The TEST interface 15 and the RST interface 16 are respectively connected to the sixth and seventh interfaces of the microprocessor 3. The wire connection between the sixth interface of the microprocessor 3 and the TEST interface 15 is externally connected to a 0Ω resistor, and the wire connection between the seventh interface of the microprocessor 3 and the RST interface 16 is externally connected to a 10Ω resistor. The wire connection between the seventh interface of the microprocessor 3 and the RST interface 16 is externally grounded to GND, and a 10μF capacitor is connected between them.

[0090] Figure 7 Shows the I / V conversion circuit diagram according to an embodiment of the present invention.

[0091] Figure 7An I / V conversion circuit is shown. The simplest way of I / V conversion is to connect a resistor in series. Generally, a sampling resistor can be used to achieve I / V conversion when dealing with large currents. However, since the analog sun sensor generates a weak current, a transimpedance amplifier circuit is adopted. The transimpedance amplifier 11 has an extremely low bias current and an extremely high input impedance, and stably outputs the photocurrents of each quadrant of the analog sun sensor as voltages.

[0092] After the I / V conversion, after converting the current into a voltage signal, an adjustable inverting amplifier 12 is added. Since the inverting amplifier circuit can both amplify and attenuate, the detectable signal range is greatly expanded. The last stage uses an operational amplifier as a subtractor 13. In the general use of photovoltaic cells, there is an influence of dark current. The subtractor 13 can adjust the output zero point or raise the signal above zero, which is convenient for the current acquisition of the unipolar analog sun sensor.

[0093] Although some embodiments of the present invention have been described in this application document, those skilled in the art can understand that these embodiments are only shown as examples. Those skilled in the art can conceive numerous variant schemes, alternative schemes, and improvement schemes under the teaching of the present invention without exceeding the scope of the present invention. The appended claims are intended to define the scope of the present invention and thereby cover the methods and structures within the scope of these claims themselves and their equivalent transformations.

Claims

1. A passive wireless analog sun sensor system, characterized in that, Comprising: An NFC wireless receiving module, which is configured to supply power to the NFC analog sun sensor patch and receive digital information of the sun ray angle sent by the NFC analog sun sensor patch; And An NFC analog sun sensor patch, which includes: A four-quadrant solar cell, which is configured to generate a photocurrent; An I / V conversion circuit, which is connected to the four-quadrant solar cell and is configured to convert the photocurrent into an analog voltage; and A microprocessor, which is connected to the I / V conversion circuit and the NFC antenna and is configured to process the analog voltage to generate digital information of the sun ray angle; An NFC chip, which is connected to the NFC antenna and the microprocessor; And An NFC antenna, which is configured to send digital information of the sun ray angle to the NFC wireless receiving module and obtain energy from the NFC wireless receiving module to supply the NFC chip, the I / V conversion circuit and the microprocessor.

2. The passive wireless analog sun sensor system according to claim 1, characterized in that, Further comprising: A housing, wherein the I / V conversion circuit, the microprocessor, the NFC chip and the NFC antenna are arranged at the bottom of the housing; An optical head end cap, which is arranged at the top of the housing, and a middle part of the optical head end cap has a window opening.

3. The passive wireless analog sun sensor system according to claim 2, characterized in that, The four-quadrant solar cell is arranged between the optical head end cap and the housing, and at least a part of the four-quadrant solar cell is exposed at the window opening of the optical head end cap; The four-quadrant solar cell includes four sub-solar cells, and at least a part of each sub-solar cell is exposed from the window opening of the optical head end cap, and there is a gap between the four sub-solar cells.

4. The passive wireless analog sun sensor system according to claim 2, characterized in that, A multi-layer PCB board is arranged at the bottom of the housing, and the I / V conversion circuit, the microprocessor, the NFC chip and the NFC antenna are arranged on the PCB board; and The I / V conversion circuit, the microprocessor and the NFC chip are all arranged in the area surrounded by the NFC antenna.

5. The passive wireless analog sun sensor system according to claim 1, characterized in that, The I / V conversion circuit is connected between the NFC chip and the microprocessor, and two pins of the microprocessor are connected to the NFC antenna.

6. The passive wireless analog sun sensor system according to claim 1, characterized in that The equivalent inductance value of the NFC antenna is 1.5 - 1.8 μH; The NFC antenna is square, with a side length of 2 cm, a line width of 0.6 mm, a line pitch of 0.6 mm, and 4 turns of coil.

7. The passive wireless analog sun sensor system according to claim 1, characterized in that, The I / V conversion circuit includes a current-voltage conversion module and a low-pass filtering module, and the current-voltage conversion module is connected to the four-quadrant solar cell; The microprocessor includes a CPU, an A / D conversion and a memory, wherein the A / D conversion is used to process the analog voltage to generate digital information of the sun ray angle; The NFC chip includes an energy management module and a storage module, wherein the energy management module supplies power to the microprocessor and the I / V conversion circuit.

8. A satellite spacecraft, which includes the passive wireless analog sun sensor system according to any one of claims 1 to 7.

9. The satellite spacecraft according to claim 8, wherein, Further comprising: A satellite cabin body; A solar panel, which is arranged on one side of the satellite cabin body.

10. The satellite spacecraft according to claim 9, characterized in that, The NFC wireless receiving module is arranged outside the satellite cabin body; and Multiple NFC analog sun sensors patches are arranged on the exterior of the satellite cabin and on the solar panels, and the distance between the NFC wireless receiving module and multiple NFC analog sun sensors patches is less than 1 meter.

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