Space camera master control main and standby single machine digital temperature cross collection circuit

Abstract

This invention relates to a single-unit digital temperature cross-acquisition circuit for a space camera's main control and backup systems. It relates to the field of space camera measurement and control and embedded circuit design technology, addressing the technical deficiencies in temperature acquisition within existing redundant main control and backup systems for space cameras. The circuit includes a primary processor, a primary temperature sensor, a primary-side near-end buffer, a primary-side far-end buffer, a primary first Schottky diode, and a primary second Schottky diode. The backup main control unit includes a backup processor, a backup temperature sensor, a backup-side near-end buffer, a backup-side far-end buffer, a backup first Schottky diode, and a backup second Schottky diode. This invention offers advantages such as multi-level power isolation to prevent cross-current flow; two-level buffered drive for long-distance transmission; remote common power design to eliminate acquisition blind spots; precise address differentiation for conflict-free cross-acquisition; and single-point dual-redundant temperature measurement for strong fault tolerance.

Description

Technical Field

[0001] This invention relates to the field of space camera measurement and control and embedded circuit design technology, specifically to a redundancy operating mode adapted to the main control unit of a space camera with a single-unit, single-copy power-on configuration, based on a digital temperature sensor and I... 2 The long-line temperature cross-acquisition circuit of the C-bus solves technical problems such as main and backup power failure, long-line transmission signal attenuation, single-power-on mode acquisition failure, and lack of redundancy in single-point temperature measurement in space camera main control systems through multi-level P82B96 bus buffer drive and 1N5819 Schottky diode power isolation protection. It is suitable for space camera main control systems with stringent requirements for circuit reliability, stability, and anti-interference in aerospace space exploration, high-orbit remote sensing, etc. Background Technology

[0002] As the core imaging equipment for aerospace exploration, space cameras generally adopt a primary and backup redundant architecture consisting of a primary main control unit and a backup main control unit to avoid the risk of system failure caused by single-unit failure. Due to the limitations of power consumption control in the space environment and the requirements for hardware lifespan assurance, only the primary unit is powered on and working during normal system operation, while the backup unit is in a power-off standby state. Only when the primary unit fails will a primary-backup switch be performed to power on.

[0003] Temperature is a key parameter affecting the operational stability, lifespan, and imaging accuracy of core components such as the optical system and imaging detector of a space camera. Traditional temperature acquisition methods cannot meet the stringent operating requirements of space cameras and have many technical shortcomings, as follows:

[0004] 1. High risk of cross-current between main and backup power supplies and insufficient hardware reliability: The main and backup power domains of the space camera are independent of each other. Direct connection to the acquisition bus can easily lead to power backflow and cross-current problems. At best, it will interfere with the stability of temperature acquisition signals, and at worst, it will burn out core components such as processors and sensors, making it difficult to meet the high reliability requirements of space equipment.

[0005] 2. Single-point temperature measurement without redundancy, and easy failure to acquire data: Traditional solutions mostly use single-sensor single-point temperature measurement without redundancy backup design. Once the temperature sensor is damaged or the link fails, the temperature acquisition at that point is completely interrupted. There is no backup acquisition channel, which seriously affects the temperature control safety of the space camera.

[0006] 3. Poor adaptability to long-distance transmission, signal attenuation and distortion: The internal structure of the space camera is compact and the temperature measurement points are scattered. Temperature acquisition requires long-distance cabling. Traditional single-level buffered or unbuffered acquisition architectures cannot compensate for long-distance I / O. 2 The C-bus signal loss can easily lead to communication distortion, abnormal temperature measurement data, and difficulty in guaranteeing the accuracy of data acquisition.

[0007] 4. Single-power mode has blind spots and lacks redundancy: the main and backup units are powered on at different times. When the power is off, the processor and acquisition link on the side are not powered. Only the powered main unit can monitor the local temperature and cannot obtain the temperature data of the power-off backup unit. There is no redundancy verification mechanism, and sensor or acquisition link failures cannot be identified and located in a timely manner.

[0008] 5. Bus interference is a significant problem, resulting in poor data acquisition stability: The processor I on the power-off side... 2 When the C bus pin is in a high-impedance or unknown-level state, it directly interferes with the bus communication on the power-on side, or even blocks data transmission, causing the temperature acquisition function to fail intermittently.

[0009] 6. Sensor address conflict, unable to achieve cross-addressing: When multiple temperature sensors of the same model are deployed on the same bus, address conflict problems are likely to occur. The power-on unit cannot accurately distinguish between the master and backup sensors, making it difficult to achieve bidirectional cross-acquisition and data comparison and verification.

[0010] To address the aforementioned technical issues, there is an urgent need to design a highly reliable temperature acquisition circuit that meets the requirements of single-battery operation, long-distance transmission, and cross-acquisition for space cameras, thus filling the technological gap in the field of highly reliable temperature acquisition for space cameras. Summary of the Invention

[0011] To address the technical deficiencies in temperature acquisition of existing redundant systems for space camera main control, this invention proposes a digital temperature cross-acquisition circuit for space camera main control and backup single-unit operation under actual working conditions of long-distance temperature measurement.

[0012] A space camera main control and backup single-unit digital temperature cross-acquisition circuit includes a primary main control unit and a backup main control unit. The primary main control unit includes a primary processor, a primary temperature sensor, a primary-side near-end buffer, a primary-side far-end buffer, a primary first Schottky diode, and a primary second Schottky diode. The backup main control unit includes a backup processor, a backup temperature sensor, a backup-side near-end buffer, a backup-side far-end buffer, a backup first Schottky diode, and a backup second Schottky diode.

[0013] The primary temperature sensor and the backup temperature sensor are both located at the same temperature acquisition point on the space camera. The ADD pin of the primary temperature sensor is pulled up to the power output of the primary second Schottky diode and configured with address 1. The ADD pin of the backup temperature sensor is pulled down to GND and configured with address 0.

[0014] The main power supply, after passing through the main first Schottky diode, supplies power to the main control unit side near-end buffer, and the main power supply, after passing through the main second Schottky diode, supplies power to the main side far-end buffer and the main temperature sensor.

[0015] The backup power supply supplies power to the near-end buffer of the backup main control unit after passing through the first backup Schottky diode, and supplies power to the far-end buffer and the backup temperature sensor after passing through the second backup Schottky diode.

[0016] The output terminals of the primary second Schottky diode and the backup second Schottky diode are shorted to form a remote common power supply node, which is used to maintain power on the two sensors and the remote buffer in single-power mode;

[0017] The host-side I of the primary-side proximal buffer and the backup-side proximal buffer 2 The C bus is connected to the I bus of the main control unit. 2 C interface and backup main control unit I 2 C-interface connection; slave-side I / O of primary-side near-end buffer and backup-side near-end buffer. 2 The C-buses are merged and connected to form a cross-access bus, which is connected to their respective remote buffers and temperature sensors to enable shared access and cross-addressing of the two sensors.

[0018] The beneficial effects of this invention are:

[0019] The cross-acquisition circuit described in this invention is fully adapted to the stringent requirements of space cameras for high reliability, long-term stability, and anti-interference, and has the following advantages:

[0020] Multi-level power isolation eliminates cross-current and backflow: The 1N5819 Schottky diode is used for unidirectional power supply and reverse cutoff of main and backup power supplies, achieving complete isolation between the main and backup power domains and completely eliminating cross-current and backflow problems in the space camera. At the same time, it achieves electrical isolation between the near-end processor domain and the far-end sensor domain, providing comprehensive protection for core hardware such as processors, sensors, and buffers, preventing hardware burn-out and damage, and greatly improving the reliability of circuit operation.

[0021] Two-stage buffered drive for long-distance transmission: Utilizing a near-end + far-end two-stage P82B96 dual-channel bidirectional bus buffer architecture, the near-end buffer effectively blocks power-off level interference, while the far-end buffer precisely compensates for signal attenuation over long distances and enhances bus drive capabilities. Even with long internal wiring in space cameras, it can guarantee I / O performance. 2 The C-band communication is stable, the temperature measurement data is accurate, and there is no signal distortion or data packet loss.

[0022] Remote common power design eliminates data acquisition blind spots: Through the design of remote common power supply node, regardless of whether the main or backup unit is powered on, both temperature sensors and remote buffers can be powered normally and continuously, breaking the temperature acquisition blind spot in single power mode. The powered unit can collect dual data from the same temperature measurement point throughout the entire process, realizing redundant temperature measurement at all times and ensuring uninterrupted temperature monitoring.

[0023] Precise address differentiation, conflict-free cross-sampling: Utilizing the pull-up / pull-down configuration of the TMP119 sensor's ADD pin to avoid I / O conflicts. 2 C-bus communication conflicts are eliminated to ensure that the power-on unit accurately addresses the primary and backup sensors, achieving unique differentiation between the primary and backup sensor addresses (primary address 1, backup address 0). The power-on unit can accurately address and read data from both sensors without conflict, successfully completing bidirectional cross-acquisition and data comparison, and adapting to the redundant measurement and control requirements of space cameras.

[0024] Single-point dual-redundancy temperature measurement with strong fault tolerance: Two TMP119 sensors, one primary and one backup, are deployed at the same point to form a single-point dual-redundancy temperature measurement architecture. If one sensor fails, is damaged, or its corresponding link is abnormal, the other sensor can independently complete the temperature acquisition at that point, completely eliminating the problem of temperature acquisition interruption caused by single-point failure. Cross-comparison and verification of dual-redundant temperature data at the same acquisition point can quickly identify the fault location, trigger alarms and primary / backup switching logic, and improve the temperature control reliability and fault self-healing capability of the space camera's main control system. This further significantly improves the continuous reliability and fault tolerance of temperature acquisition in the space camera's main control unit, meeting the long-term stable operation requirements of space equipment.

[0025] The overall circuit architecture is simple and optimized, making it easy to implement in engineering: the overall circuit does not require the addition of complex control logic and dedicated chips, and all functions are achieved by combining conventional components. The circuit is small in size, has low power consumption, and controllable cost, making it suitable for the compact embedded deployment requirements of space cameras. It is easy to implement in engineering and has wide applicability to space environments. Attached Figure Description

[0026] Figure 1 This is a block diagram of the main control and standby single-unit digital temperature cross-acquisition circuit for the space camera of the present invention. Detailed Implementation

[0027] Specific Implementation Method 1: Combination Figure 1 This embodiment describes a single-unit digital temperature cross-access circuit for a space camera's main control and backup systems. The circuit is divided into three main units: a temperature acquisition link, a power protection module, and a cross-bus module, and is fully compatible with I / O. 2 The C digital communication protocol enables full functionality including anti-current isolation, long-line drive, cross-acquisition, and redundancy verification.

[0028] In this embodiment, the temperature sensor is a TMP119 digital temperature sensor, the buffer is a P82B96 dual-channel bidirectional bus buffer, and the diode is a 1N5819 Schottky diode.

[0029] The core hardware components of the temperature cross-acquisition circuit described in this embodiment include a primary main control unit (including a processor) and a backup main control unit (including a processor), and the temperature acquisition link includes a primary TMP119 digital temperature sensor and a backup TMP119 digital temperature sensor.

[0030] The cross-bus module includes a primary side near-end P82B96 dual-channel bidirectional bus buffer, a primary side far-end P82B96 dual-channel bidirectional bus buffer, a backup side near-end P82B96 dual-channel bidirectional bus buffer, and a backup side far-end P82B96 dual-channel bidirectional bus buffer.

[0031] The power protection module includes a primary first 1N5819 Schottky diode, a primary second 1N5819 Schottky diode, a backup first 1N5819 Schottky diode, and a backup second 1N5819 Schottky diode;

[0032] In this embodiment, the temperature acquisition is connected to the bus;

[0033] Primary side acquisition link: The primary TMP119 sensor is deployed at a temperature acquisition point on the space camera. Its ADD pin is pulled up to the output of the primary second 1N5819 Schottky diode, and the device address is configured to 1; 2 The C bus pins (SDA / SCL) are connected to the slave-side port of the P82B96 dual-channel bidirectional bus buffer on the master side. This remote buffer is connected via a long line I. 2 The C-bus connects to the slave-side port of the P82B96 dual-channel bidirectional bus buffer on the near end of the master unit. The near end buffer is positioned close to the master unit.

[0034] Backup side acquisition link: The backup TMP119 sensor is deployed at the same point as the primary TMP119 sensor, and its ADD pin is connected to GND pull-down, configured with device address 0; 2 The C bus pins (SDA / SCL) are connected to the slave-side port of the backup-side P82B96 dual-channel bidirectional bus buffer. This remote buffer is connected via a long line I. 2 The C-bus connects to the slave port of the P82B96 dual-channel bidirectional bus buffer on the backup side, with the buffer positioned close to the backup master control unit.

[0035] In this embodiment, the cross-access bus consists of a primary side near end, a backup side near end, and a P82B96 dual-channel bidirectional bus buffer on the host side I. 2 Each C bus is independent and connected to the I / O pins of the primary and backup master control units, respectively. 2 C communication interface; slave side I of P82B96 dual-channel bidirectional bus buffer, primary side near end, backup side near end. 2The C-buses are merged and connected to form a unified cross-access bus, which connects to their respective remote buffers and temperature sensors, enabling the primary or backup processor to share access to and cross-address the two sensors.

[0036] In this embodiment, the power supply anti-interference and power supply connection are implemented as follows:

[0037] Main unit near-end power supply: The main unit's 3.6V power supply, after passing through the main unit's first 1N5819 Schottky diode, supplies power to the main unit's main control unit's near-end P82B96 dual-channel bidirectional bus buffer, achieving unidirectional power supply and reverse isolation.

[0038] Main unit remote power supply: The main unit's 3.6V power supply, after passing through the main unit's second 1N5819 Schottky diode, powers the main unit's remote P82B96 dual-channel bidirectional bus buffer and the main unit's TMP119 digital temperature sensor.

[0039] Backup near-end power supply: The backup 3.6V power supply, after passing through the backup first 1N5819 Schottky diode, supplies power to the P82B96 dual-channel bidirectional bus buffer near the backup main control unit side, realizing unidirectional power supply and reverse isolation.

[0040] Backup remote power supply: The backup 3.6V power supply, after passing through the backup second 1N5819 Schottky diode, powers the backup remote P82B96 dual-channel bidirectional bus buffer and the backup TMP119 digital temperature sensor.

[0041] Remote common power supply: The output terminals of the primary second 1N5819 Schottky diode and the backup second 1N5819 Schottky diode are shorted to form a remote common power supply node, ensuring that both remote buffers and both temperature sensors can be powered on normally in single-power operation mode.

[0042] The temperature cross-acquisition circuit described in this embodiment is compatible with two core operating conditions of space cameras: primary and backup single-unit power-on. The operating logic is symmetrical in both conditions, achieving anti-current leakage, no blind spots, redundant acquisition, and data verification, as detailed below:

[0043] Operating Condition 1: The primary control unit is powered on and working, while the backup control unit is powered off and in standby mode (cold backup).

[0044] Power supply isolation: The main 3.6V power supply is supplied to the near-end and far-end circuits of the main unit through the first and second 1N5819 Schottky diodes of the main unit, respectively. The first and second 1N5819 Schottky diodes of the main unit are forward-biased, while the first and second 1N5819 Schottky diodes of the backup are reverse-biased, completely blocking the main and backup power supply from cross-current and backflow; the far-end common power supply node is supplied by the second Schottky diode of the main unit, and the two far-end buffers and the two TMP119 digital temperature sensors are all powered on normally.

[0045] Bus isolation driver: The primary-side near-end buffer is normally powered on, while the backup-side near-end buffer is not powered due to backup power failure, thus blocking interference from the backup-side power failure pin to the merged bus; the two-stage buffers work together to compensate for long-line signal attenuation, ensuring I... 2 C-bus communication is stable.

[0046] Cross-acquisition addressing: The primary and backup TMP119 digital temperature sensors with address 1 and address 0 respectively are accessed through the cross-acquisition bus, and the two redundant temperature data of the same acquisition point are acquired simultaneously. Even if one of the temperature sensors fails, the other temperature sensor can still complete the temperature acquisition at that point normally, ensuring that the acquisition function is uninterrupted.

[0047] Data comparison and verification: The primary and secondary control units compare the differences between the two temperature data. If the difference is within the preset threshold, the acquisition link is determined to be normal. If the difference exceeds the preset threshold, a single temperature sensor, buffer, or bus link is determined to be abnormal. A temperature abnormality alarm signal is output, and the primary / backup switching logic is triggered.

[0048] Operating Condition 2: The backup main control unit is powered on and working, while the primary main control unit is powered off and in standby mode;

[0049] Power supply isolation: The backup 3.6V power supply is powered by two stages of 1N5819 Schottky diodes, which power the backup near-end and far-end circuits respectively. The first and second Schottky diodes of the backup are forward-biased, while the first and second Schottky diodes of the main backup are reverse-biased to prevent cross-current and backflow between the main and backup power supplies. The remote common power supply node is powered by the second Schottky diode of the backup. Both remote buffers and both TMP119 sensors are powered on normally.

[0050] Bus isolation driver: The backup-side near-end buffer is normally powered on, while the primary-side near-end buffer is not powered due to a power outage on the primary side, thus blocking interference from the primary-side power-off pins to the merged bus; the two-stage buffers work together to protect the long-line I 2 C. Communication is stable.

[0051] Cross-acquisition addressing: The backup master control unit addresses the backup TMP119 temperature sensor with address 0 and the master TMP119 temperature sensor with address 1 respectively through the cross-acquisition bus, and synchronously acquires two redundant temperature data from the same acquisition point; even if one sensor fails, the other sensor can still complete the temperature acquisition at that point normally, ensuring uninterrupted acquisition function.

[0052] Data comparison and verification: The backup main control unit compares the differences between the two temperature data. When it determines that the acquisition link is abnormal, it outputs a temperature abnormality alarm signal and triggers the main backup switchback logic to ensure the temperature control safety of the space camera main control system.

[0053] In this embodiment, the acquisition circuit uses a main / backup 3.6V power supply split into two paths via corresponding 1N5819 Schottky diodes. The near-end branch powers the corresponding near-end buffer, while the far-end branch powers the corresponding far-end buffer and temperature sensor. The outputs of the second Schottky diodes in the main and backup circuits are shorted to form a common power supply node at the far end. The two-stage buffers are connected via a long line I. 2 The C-bus connection, with the near-end buffer converging from the machine side into a cross-access bus, allows for cross-addressing of the primary and backup processors; the primary and backup temperature sensors are deployed at the same point. The core functions of the circuit are protection against power supply crosstalk, backflow, and long-line I / O. 2 C-signal compensation, single-point dual-redundancy temperature measurement, dual-sensor continuous power-on in single-power mode, and cross-data comparison and verification.

[0054] Specific Implementation Method Two: This implementation method is an embodiment of the digital temperature cross-acquisition circuit for a space camera main control and backup single unit described in Specific Implementation Method One. This embodiment strictly meets the working conditions of power-on and long-term temperature measurement of the space camera main control and backup single unit. The hardware selection, wiring configuration and software logic all meet the reliability standards of aerospace-grade equipment.

[0055] In this embodiment, the temperature sensing device is a TMP119 digital temperature sensor, which achieves high-precision, wide-temperature-range temperature measurement; the bus buffer device is a P82B96 dual-channel bidirectional bus buffer, which meets I... 2 The C-bus requires long-line drive and isolation; the 1N5819 Schottky diode is selected as the power isolation device to achieve unidirectional power supply and anti-crosstalk; the performance indicators of all devices meet the requirements of the space camera I. 2 It meets stringent requirements for C-bus communication, power isolation, long-line drive, and protection against backflow, while also adapting to the anti-interference and low-power consumption needs of the space environment.

[0056] In this embodiment, the TMP119 digital temperature sensor is a high-precision, low-power, and small-size digital temperature measuring device, and is equipped with standard I. 2 The C communication interface features wide temperature range operation and strong anti-interference characteristics, and comes with an ADD address configuration pin. Both temperature sensors are deployed on the space camera at the same critical temperature acquisition point, achieving single-point dual-redundancy temperature measurement. The temperature at this point is accurately acquired and converted into a digital signal output. The bus can be conflict-free addressed through address differentiation configuration. The failure of a single sensor does not affect the overall acquisition function, making it suitable for the harsh operating conditions of the space camera.

[0057] In this embodiment, the P82B96 dual-channel bidirectional bus buffer is specifically designed for I... 2The dedicated bidirectional buffer for the C-bus design features strong electrical isolation, level adaptation, signal driving, and long-line compensation capabilities, supporting unidirectional conduction and bidirectional transmission. The near-end buffer is positioned close to the corresponding processor to block level interference on the power-off side; the far-end buffer is positioned close to the corresponding sensor to compensate for long-line signal attenuation. This two-stage buffering system works together to ensure I... 2 The C-bus communication is stable and suitable for long-distance temperature measurement cabling scenarios for space cameras.

[0058] In this embodiment, the 1N5819 Schottky diode utilizes its unidirectional conduction, reverse cutoff, and low voltage drop electrical characteristics to achieve main and backup power supply branching and electrical isolation, effectively preventing power supply crosstalk and backflow; at the same time, it works in conjunction with the establishment of a remote common power supply node to ensure continuous power supply to the sensor and remote buffer in single-power mode, adapting to the low power consumption and high reliability power supply requirements of the space camera.

[0059] 1. Hardware Wiring: The primary TMP119 digital temperature sensor and the backup TMP119 digital temperature sensor are closely arranged at the same critical temperature acquisition point of the space camera to ensure the consistency of temperature measurement data; the ADD pin of the primary TMP119 is connected to the remote common power supply (output of the primary second 1N5819 Schottky diode) through a pull-up resistor, configured with address 1; the ADD pin of the backup TMP119 is connected to GND through a pull-down resistor, configured with address 0; the near-end and far-end P82B96 dual-channel bidirectional bus buffer, the primary and backup main control units, and the TMP119 digital temperature sensors are strictly powered by the branch 1N5819 Schottky diodes, and the remote common power supply node is firmly shorted to avoid poor contact; long line I 2 The C-bus uses shielded cables for wiring to reduce the impact of electromagnetic interference in the environment on communication signals.

[0060] 2. Software Logic: Both the primary and backup processors have built-in standardized temperature acquisition and verification programs, which automatically complete I / O upon power-up. 2 The C interface is initialized, and temperature data from two TMP119 digital temperature sensors are collected by polling at address 1 and address 0. The preset normal temperature difference threshold between the two temperature data is ±2℃. If the difference between the two collected data exceeds this threshold, the processor immediately outputs a temperature abnormality alarm signal and links the master / slave switching module to perform master / slave switching / return switching operations to achieve seamless fault switching. The program also has a data caching function to ensure that temperature data is not lost during the switching process, thus ensuring the continuity and stability of temperature control in the space camera's main control system.

[0061] The acquisition circuit described in this embodiment has a simple circuit architecture, reasonable wiring, and standardized software logic. It can realize blind-zone-free temperature cross-acquisition in main and backup single-power mode, effectively solving the problems of cross-current, signal attenuation, acquisition failure, and lack of redundancy in traditional solutions. The component selection is conventional and the cost is controllable. The hardware wiring has no complex process requirements and can be directly applied to the embedded deployment of the space camera main control system. It has strong engineering feasibility and has broad application prospects in aerospace space exploration, high-orbit remote sensing and other fields.

[0062] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0063] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A space camera main control and backup single-unit digital temperature cross-acquisition circuit, wherein the acquisition circuit includes a primary main control unit and a backup main control unit; characterized in that: The primary control unit includes a primary processor, a primary temperature sensor, a primary-side proximal buffer, a primary-side distal buffer, a primary first Schottky diode, and a primary second Schottky diode; the backup control unit includes a backup processor, a backup temperature sensor, a backup-side proximal buffer, a backup-side distal buffer, a backup first Schottky diode, and a backup second Schottky diode. The primary temperature sensor and the backup temperature sensor are both located at the same temperature acquisition point on the space camera. The ADD pin of the primary temperature sensor is pulled up to the power output of the primary second Schottky diode and configured with address 1. The ADD pin of the backup temperature sensor is pulled down to GND and configured with address 0. The main power supply, after passing through the main first Schottky diode, supplies power to the main control unit side near-end buffer, and the main power supply, after passing through the main second Schottky diode, supplies power to the main side far-end buffer and the main temperature sensor. The backup power supply supplies power to the near-end buffer of the backup main control unit after passing through the first backup Schottky diode, and supplies power to the far-end buffer and the backup temperature sensor after passing through the second backup Schottky diode. The output terminals of the primary second Schottky diode and the backup second Schottky diode are shorted to form a remote common power supply node, which is used to maintain power on the two sensors and the remote buffer in single-power mode; The host-side I of the primary-side proximal buffer and the backup-side proximal buffer 2 The C bus is connected to the I bus of the main control unit. 2 C interface and backup main control unit I 2 C-interface connection; slave-side I / O of primary-side near-end buffer and backup-side near-end buffer. 2 The C-buses are merged and connected to form a cross-access bus, which is connected to their respective remote buffers and temperature sensors to enable shared access and cross-addressing of the two sensors.

2. The space camera main control standby single-unit digital temperature cross-acquisition circuit according to claim 1, characterized in that: When the acquisition circuit is working, only one copy of the main and backup units is powered on and operates. Schottky diodes provide power domain isolation between the main and backup units to prevent cross-current and reverse current. Near-end and far-end buffers provide long-line I / O protection. 2 C signal compensation and bus isolation are achieved by addressing the corresponding temperature sensor via the cross-access bus using address 1 and address 0 respectively, thus completing dual-redundant temperature acquisition and data comparison verification at the same acquisition point.

3. The space camera main control standby single-unit digital temperature cross-acquisition circuit according to claim 1, characterized in that: The primary-side near-end buffer, primary-side far-end buffer, backup-side near-end buffer, and backup-side far-end buffer all adopt the P82B96 dual-channel bidirectional bus buffer.

4. The space camera main control standby single-unit digital temperature cross-acquisition circuit according to claim 1, characterized in that, The primary first Schottky diode, the primary second Schottky diode, the backup first Schottky diode, and the second Schottky diode all use 1N5819 Schottky diodes, and all achieve unidirectional conduction and reverse cutoff.

5. The space camera main control standby single-unit digital temperature cross-acquisition circuit according to claim 1, characterized in that: When the primary control unit is powered on and the backup control unit is powered off, the remote common power supply node is powered by the second Schottky diode of the primary unit; when the backup control unit is powered on and the primary control unit is powered off, the remote common power supply node is powered by the second Schottky diode of the backup unit, ensuring continuous power supply to the two temperature acquisition links in single-power mode.

6. The space camera main control standby single-unit digital temperature cross-acquisition circuit according to claim 1, characterized in that: When powered on, the primary or backup main control unit compares the differences between two redundant temperature data points at the same acquisition point. If the difference exceeds a preset threshold, it determines that a single temperature sensor or its corresponding link is abnormal, outputs a temperature abnormality alarm signal, and triggers primary / backup switching or hardware protection logic. Furthermore, a single sensor failure does not affect the temperature acquisition at that point.

7. The space camera main control standby single-unit digital temperature cross-acquisition circuit according to claim 1, characterized in that: In actual operation of the acquisition circuit, the primary control unit is powered on and working, while the backup control unit is powered off and in standby mode. It enables power supply isolation, bus isolation drive, cross-acquisition addressing, and data comparison and verification functions; Power supply conduction isolation: The main power supply is supplied to the main near-end and far-end circuits respectively through the main first Schottky diode and the main second Schottky diode. The main first Schottky diode and the main second Schottky diode are forward conducting, while the backup first Schottky diode and the backup second Schottky diode are reverse cut off. The remote common power supply node is powered by the primary second Schottky diode. The primary side remote buffer, the backup side remote buffer circuit, the primary temperature sensor and the backup temperature sensor are all powered on normally. Bus isolation driver: The primary side near-end buffer is normally on, while the backup side near-end buffer is powered off and has no power supply. The primary side near-end buffer and the primary side far-end buffer work together to compensate for long-line signal attenuation, ensuring I... 2 C-bus communication is stable; Cross-acquisition addressing: The primary and secondary control units address the primary temperature sensor with address 1 and the backup temperature sensor with address 0 respectively through the cross-acquisition bus, and synchronously acquire two redundant temperature data from the same acquisition point. Data comparison and verification: The main control unit compares the difference between the two temperature data. If the difference is within the preset threshold, the acquisition link is determined to be normal. If the difference exceeds the preset threshold, it is determined that a single temperature sensor, buffer, or bus link is abnormal, a temperature abnormality alarm signal is output, and a master-slave switch is triggered.

8. The space camera main control standby single-unit digital temperature cross-acquisition circuit according to claim 1, characterized in that: In actual operation of the acquisition circuit, the backup main control unit is powered on and working, while the main control unit is powered off and in standby mode. Its power supply isolation, bus isolation drive, cross acquisition addressing, and data comparison and verification functions are the same as the process when the main control unit is powered on and the backup control unit is powered off and in standby mode.

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