Detachable test cable for spacecraft and construction method

Abstract

The invention provides a detachable test cable for a spacecraft and a construction method, and the method comprises the steps: 1, carrying out the classification and bundling according to the functions and directions of signals distributed in a source-end single-machine electric connector and a terminal single-machine electric connector on the spacecraft, and then forming an on-device cable; 2, combining the requirement that signals in a terminal single-machine electric connector are led out to ground testing equipment, and forming detachable testing cables after classifying and bundling according to the attributes, the destination and the number of the signals; 3, according to the opportunity of ground testing or launching injection, the detachable testing cable is linked in or detached, so that different signal communication modes are formed; wherein the detachable test cable is connected with the on-device cable through a chain-in Y-type, V-type or W-type cable branch. The device can be directly dismantled after a ground test is finished without influencing the state of an original cable on the device, the task requirement of the ground test is ensured, the weight of the cable on the device during launching injection is reduced, and the device has engineering practical value.

Description

Technical Field

[0001] This invention relates to the field of detachable test cable technology, and more specifically, to a detachable test cable for spacecraft and a method for its installation. Background Technology

[0002] Micro-spacecraft integrate advanced technologies and processes such as microelectromechanical systems (MEMS), and typically weigh between 50 and 500 kg. They include various microsatellites and micro-space technology experimental vehicles. Compared to large and medium-sized spacecraft with equivalent functions, micro-spacecraft have advantages such as low cost, small size and light weight, flexible launch, and timely response, enabling them to complete human space exploration, Earth observation, and other special missions.

[0003] Ground-based electrical performance testing of spacecraft plays a crucial role in the overall quality control of a satellite throughout its development process, ensuring successful flight and the completion of its mission. The comprehensiveness of ground-based electrical testing directly impacts the testing efficiency, quality, and safety of the satellite itself. For large and medium-sized spacecraft, monitoring and simulation verification of key signals from critical components often continue even after the spacecraft is sealed. A common practice is to design surface test ports near the outer casing of the spacecraft, such as… Figure 1 As shown, its main function is to relay key signals. In conjunction with the branching routes of the onboard cables, the test cables are designed to guide important signals from key components of the spacecraft to ground-based test equipment, facilitating connections and ensuring comprehensive testing coverage. The drawback is that this section of cable cannot be removed after spacecraft testing; it must be carried into orbit with the spacecraft. For micro-spacecraft, this test cable often represents a significantly larger proportion of the overall payload than for large or medium-sized spacecraft. Carrying it into orbit results in a substantial waste of resources, especially for micro-spacecraft with stringent weight requirements.

[0004] Patent document CN106557632B discloses a rapid and universal design method for cable networks in a satellite GNC semi-physical simulation system, which includes the following steps: classifying the electrical interfaces of each unit and test equipment in the satellite GNC semi-physical simulation system according to signal type; using the same connector for electrical interfaces of the same signal type; defining the contact points of the connectors; and setting the length of the cables connected to the connectors to a preset length to complete the design of the cable network.

[0005] Patent document CN206223896U discloses a portable testing device for low-frequency satellite-to-ground cables, including a universal low-frequency satellite-to-ground cable testing platform, an adapter cable, a shorting connector, and a digital multimeter. The universal low-frequency satellite-to-ground cable testing platform performs performance testing on the cable under test; the adapter cable completes the electrical interface matching between the cable under test and the universal low-frequency satellite-to-ground cable testing platform; the shorting connector short-circuits each test point; and the digital multimeter is used for resistance testing.

[0006] Patent document CN107658833B discloses an optimized wiring method that meets the rotation requirements of an external radio frequency cable. The radio frequency cable includes a deformable section, a movable section, and a fixed section. Before unfolding, the deformable section of the radio frequency cable is U-shaped, and after unfolding, the deformable section of the radio frequency cable is arc-shaped. The unfolding angle of the cable is no more than 120 degrees.

[0007] Patent document CN113629607B discloses a cable bundle structure and wiring method suitable for spacecraft, including a column-cone assembly. The column-cone assembly includes a first conical barrel, a second conical barrel, and a column barrel. The first and second conical barrels are respectively connected to both ends of the column barrel. A top plate and a shelf plate are provided on the column-cone assembly. The top plate is provided on the first conical barrel, and the shelf plate is connected at the connection position between the first conical barrel and the column barrel. A top plate cable bracket is provided on the top plate, a shelf plate cable bracket is provided on the shelf plate, and a lightweight cable bracket is provided on the first conical barrel. An operating hole is provided on the first conical barrel. A traction rope is provided on the first conical barrel, and the traction rope passes through the operating hole.

[0008] Patent document CN113183228B discloses a space-use flexible cable shaping processing device, including a cutting system, a hydraulic system, a cold working control system, and a forming device; wherein the cutting system includes a Z-axis motion mechanism, a rotation mechanism, a horizontal movement mechanism, and a cutting execution mechanism; wherein the Z-axis motion mechanism can move up and down; the rotation mechanism can rotate in space and can complete the cutting of folded flat cables; the horizontal movement mechanism can move in the X and Y axes; the cutting execution mechanism can position and cut the product; the hydraulic system is used to control the type, proportion, and volume of the cutting material used in the cutting circuit, wherein the cutting material is silicone rubber, which is a two-component material.

[0009] Patent document CN102097717B discloses an automatic cable testing and conversion system, which is a necessary testing path connecting the cable under test and the cable tester. The system consists of a universal conversion cable, a cable testing conversion box, and a special conversion cable. The universal conversion cable transitions the special-specification output connector on the cable tester to the cable testing conversion box. The special conversion cable connects the cable testing conversion box to the cable under test. The cable testing conversion box is connected to both the universal conversion cable and the special conversion cable.

[0010] However, the aforementioned patents cannot completely solve the existing technical problems, nor can they meet the needs of this invention. Summary of the Invention

[0011] In view of the deficiencies in the prior art, the purpose of this invention is to provide a detachable test cable for spacecraft and a method for its installation.

[0012] The method for constructing a detachable test cable for a spacecraft according to the present invention includes: Step 1: Based on the function and destination of the signals arranged in the source and terminal single-unit electrical connectors on the spacecraft, classify and bundle the cables on the formwork. Step 2: Based on the requirements of the signal lead-out from the terminal single-unit electrical connector to the ground test equipment, the signals are classified and bundled according to their attributes, destinations and quantities to form detachable test cables; Step 3: Depending on the timing of ground testing or launch into orbit, insert or remove the detachable test cable to establish different signal connectivity methods; The detachable test cable is connected to the cable on the device via a chain-in Y-type, V-type, or W-type cable branch.

[0013] Preferably, step 1 includes: classifying and clustering the signals from the source unit according to power supply signals, data bus signals, analog signals, and control command signals; The energy supply signal bundle is used to transmit electrical energy to the terminal power connector; the data bus signal bundle includes digital communication signals; the analog signal bundle includes sensor signals and monitoring signals; and the control command signal bundle includes switch control signals.

[0014] Preferably, the energy supply signal bundle includes a primary power supply signal and a secondary power supply signal; The data bus signal bundle includes RS422 bus signals, CAN bus signals, and 1553B bus signals; The analog signal bundle includes temperature sensor signals, pressure sensor signals, and current / voltage monitoring signals; The control command signal bundle includes attitude control commands, load switch control signals, and antenna deployment control signals.

[0015] Preferably, step 2 includes: classifying signals according to their attributes into key telemetry signals, important remote control signals, and power monitoring signals; The key telemetry signals are used for real-time monitoring, the important remote control signals are used for injection verification, and the power monitoring signals are used for power consumption analysis and system verification.

[0016] Preferably, the key telemetry signals include attitude data and angular velocity data, the important remote control signals include mode switching commands and operating mode commands, and the power monitoring signals include operating current status and voltage status.

[0017] Preferably, step 2 further includes classifying signals according to their destination into signals from a guidance semi-physical simulator, signals from a guidance integrated test bench, and signals from a guidance-specific test equipment; The signals from the guidance semi-physical simulator include attitude sensor data and actuator feedback data; the signals from the guidance integrated test bench include telemetry and remote control data and status monitoring data; and the signals from the guidance-specific test equipment include load data and image data.

[0018] Preferably, each detachable test cable contains no more than 32 signal cores.

[0019] Preferably, the electrical connector for the detachable test cable to connect with the cable on the device is the same as the electrical connector for the terminal unit, and the electrical connector for the detachable test cable to connect with the terminal unit is the same as the electrical connector for the cable on the device.

[0020] Preferably, step 3 includes: the ground testing timing includes the assembly and integration testing stage, the launch site testing stage, and the pre-packaging testing stage; the launch and orbit insertion timing includes before rocket docking and during fairing packaging. During ground testing, the detachable test cable is chained between the cable on the device and the terminal unit, forming a signal path that passes sequentially through the source unit, the cable on the device, the branch point of the detachable test cable, the ground test equipment, and the terminal unit. During launch into orbit, the detachable test cable is removed, forming a signal path that passes sequentially through the source unit, the on-board cable, and the terminal unit. The source unit is connected to the on-device cable via an electrical connector, and the terminal unit is connected to the on-device cable via an electrical connector.

[0021] The spacecraft detachable test cable provided by the present invention is constructed using the aforementioned method.

[0022] Compared with the prior art, the present invention has the following beneficial effects: (1) The cable on the device does not change its state due to the insertion or removal of the detachable test cable, and can meet the requirements of signal connection and laying path. (2) The selection of electrical connectors for detachable test cables and on-device cables is the same as that for terminal stand-alone electrical connectors. The selection of electrical connectors for terminal stand-alone cables and on-device cable electrical connectors is the same as that for on-device cables, ensuring that after the detachable test cables are detached, the on-device cables and terminal stand-alone electrical connectors can be directly connected. (3) During ground testing, the detachable test cable is chained between the onboard cable and the terminal unit; during the launch phase, the detachable test cable is removed and the onboard cable is directly connected to the terminal unit, which can flexibly adapt to the functions of ground and launch-to-orbit testing and signal communication, and minimize the unnecessary cables launched with the spacecraft. Attached Figure Description

[0023] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings: Figure 1 Cable connection diagram for leading important signals from key components of large and medium-sized spacecraft to ground test equipment; Figure 2 Cable connection diagram for leading important signals from key components of micro-spacecraft to ground test equipment; Figure 3 It is a detachable test cable; Figure 4 This is a design architecture diagram of the convenient and detachable test cable for micro-spacecraft according to the present invention. Detailed Implementation

[0024] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0025] Example This invention provides a design method for a convenient and detachable test cable for micro-spacecraft, comprising: First, based on the function and destination of the signals arranged in the source-end and terminal single-unit electrical connectors on the spacecraft, the cables on the formwork are classified, bundled, and then formed. Signal classification and beamforming process: 1) Power supply signal bundle: The primary power supply (100V, 42V, 28V) and secondary power supply (15V, 12V, 5V) from the single-unit electrical connector of the energy system are bundled according to the power distribution destination, and the power is delivered to the terminal electrical connector to form an energy bus bundle. 2) Data bus signal bundle: Digital communication signals such as RS422, CAN bus, and 1553B bus are classified according to communication protocol type to form a data bus bundle; 3) Analog signal bundling: Analog signals such as temperature sensor signals, pressure sensor signals, and current / voltage monitoring signals are bundled according to signal type and accuracy requirements; 4) Control command signal bundle: The attitude control command, load switch control, antenna deployment control and other control signals are bundled according to the command type (OC gate command, OD gate command, and RF follower command).

[0026] Specific examples: In the J30J (96-pin) electrical connector of the source-side single unit (integrated electronic computer), pins 1-12 are power signals, pins 13-36 are RS422 data signals, pins 37-60 are CAN bus signals, pins 61-84 are analog telemetry signals, and pins 85-96 are control command signals. In the J14A (26-pin) 26-pin electrical connector of the terminal unit (star sensor), pins 1-4 are for power supply, pins 5-12 are for data communication, pins 13-20 are for image data output, and pins 21-26 are for status monitoring signals. Secondly, in accordance with the requirement of leading important signals from the terminal single-unit electrical connector to ground testing equipment, the cables are bundled and classified according to the signal attributes, destination, quantity, etc. to form detachable test cables. Specifically: Signal attribute classification: 1) Key telemetry signals: star sensor attitude data (4-channel quaternion signals), gyroscope angular velocity data (3-axis × 16-bit), flywheel speed feedback (4-channel × 12-bit), etc. These signals need to be extracted to the ground-based semi-physical simulation system for real-time monitoring; 2) Important remote control signals: attitude control mode switching commands, load working mode commands, safety mode trigger signals, etc., need to be injected and verified through ground testing equipment; 3) Power monitoring signals: operating current and voltage status of each unit, used for ground power consumption analysis and power system verification.

[0027] Signal destination classification: 1) Guided semi-physical simulator: attitude sensor data, actuator feedback data; 2) Guiding integrated test bench: telemetry and control data, status monitoring data; 3) Dedicated testing equipment for guidance: load data, image data; Quantity allocation: Each detachable test cable contains no more than 32 signal cores to ensure reasonable cable diameter and weight.

[0028] Finally, depending on the timing of ground testing or launch into orbit, the detachable test cable is either chained in or detached, creating two different signal connection methods.

[0029] Among them, the timing of ground testing: 1) AIT (Assembly, Integration, and Testing) phase: After the satellite is fully assembled, electrical performance testing is conducted in a cleanroom. 2) Launch site testing phase: The final testing phase after the satellite arrives at the launch site and before it is docked with the rocket; 3) Pre-packaging test: The final ground test before the satellite is installed into the fairing; Launch timing: 1) Before rocket docking: All detachable test cables must be removed before connecting the satellite to the rocket adapter; 2) When sealing the fairing: Ensure all ground test interfaces are disconnected and the onboard cables are back to flight status; Two signal connection methods: 1) Ground test connectivity method: Source end unit → On-device cable → Detachable test cable branch point → Ground test equipment → Terminal unit; Signal flow: Important signals from the terminal unit are led out to the ground test equipment through a detachable test cable branch, while maintaining normal communication with the source unit.

[0030] 2) Launch-to-orbit connection method: Source unit → Cable on device → Terminal unit; Signal flow: After removing the detachable test cable, the on-board cable is directly connected to the terminal unit to restore the flight configuration.

[0031] By designing Y, V, or W-type cable branches, the on-board cables are decoupled from the ground test cables. This allows them to be directly removed after ground testing without affecting the original state of the on-board cables. This ensures the requirements of ground testing while reducing the weight of the on-board cables during launch and orbit insertion.

[0032] The cable on the device does not change its state due to the insertion or removal of the detachable test cable, and can meet the requirements of signal connectivity and laying path. Detachable test cables such as Figure 3 As shown, the selection of the electrical connector that connects to the on-device cable is the same as that of the terminal unit electrical connector, and the selection of the electrical connector that connects to the terminal unit is the same as that of the on-device cable electrical connector, ensuring that after the detachable test cable is disassembled, it can meet the requirement of direct connection between the on-device cable and the terminal unit electrical connector. The source unit is generally an integrated electronic computer, GNC control computer or data management computer. Its characteristic is that it is a key unit on the spacecraft and has the central management function of sending and receiving commands. Specific implementation process: 1) Command reception and processing: The source unit receives uplink commands from the ground through the onboard computer, and after command parsing, validity verification and authorization check, it forms internal control commands; 2) Command distribution and execution: Based on the command type and target unit, control commands are sent to the corresponding terminal unit through different communication interfaces (RS422, CAN, 1553B, etc.); 3) Status information collection: Periodically poll the working status, health information, and telemetry data of each terminal, and summarize and process them; 4) Data downlink management: The collected telemetry data is packaged and encoded according to the downlink strategy and then downlinked to the ground through the telemetry and control system.

[0033] Terminal units typically consist of individual components such as star sensors, flywheels, and gyroscopes. A key characteristic of these units is that, during ground testing, their critical signals need to be routed to ground-based testing equipment for semi-physical closed-loop simulation experiments. The specific experimental process is as follows: 1) Signal extraction: The quaternion attitude output signal and image data signal of the star sensor are extracted to the ground-based semi-physical simulation system through a detachable test cable; 2) Environmental simulation: Ground equipment simulates star map information of the real space environment, generates standard star map data, and injects it into the star sensor through a test cable; 3) Closed-loop verification: The star sensor calculates the spacecraft's attitude based on the simulated star map and feeds the results back to the integrated electronic computer, which then generates flywheel control commands accordingly. 4) Performance evaluation: Compare the simulated attitude with the standard attitude to evaluate the accuracy of the star sensor; monitor the response time and stability of the entire control loop; 5) Fault injection: Various fault modes (signal interruption, data error, etc.) are injected through ground equipment to verify the system's fault tolerance and fault handling logic.

[0034] Through the detailed implementation process described above, this invention can effectively solve the problem of weight redundancy in test cables for micro-spacecraft, and minimize the invalid load during launch and orbit insertion while ensuring ground test coverage.

[0035] Different signal connection methods refer to the following: during ground testing, a detachable test cable is chained between the onboard cable and the terminal unit; during the launch phase, the detachable test cable is removed, and the onboard cable is directly connected to the terminal unit, such as... Figure 2 As shown, it has the ability to flexibly adapt to ground and launch-to-orbit testing and signal communication functions, minimizing unnecessary cables during spacecraft launch.

[0036] like Figure 4 The following are provided: source unit 1, on-device cable 2, detachable test cable 3, terminal unit 4, and ground test equipment 5.

[0037] The source unit 1 (integrated electronic computer) is connected to the on-board cable 2 via a 96-pin connector; The cable 2 on the device adopts a Y-type branch design, and the main trunk is connected to the 26-pin connector of the terminal unit 4 (star sensor); The detachable test cable 3 is connected to the terminal unit via the intermediate connector cable. The test branch of the detachable test cable 3 is connected to the ground test equipment 5 via a dedicated interface.

[0038] Signal transmission process: Ground test mode: 1) The attitude control command signal issued by the source unit 1 is transmitted to the branch point of the detachable test cable 3 via the on-board cable 2. 2) The signal splits into two paths at the branch point: one path continues to be transmitted to the terminal unit 4, and the other path is led out to the ground test equipment 5; 3) The status feedback signal of the terminal unit 4 also passes through the branch point, returning to the source unit 1 and also being transmitted to the ground test equipment 5 for monitoring; 4) Ground testing equipment 5 can inject simulated signals in real time to replace real external environmental signals.

[0039] Launch-to-orbit mode: 1) After removing the detachable test cable 3, the on-device cable 2 is directly connected to the terminal unit 4 via a straight connector; 2) The signal transmission path is simplified to: source end single unit 1 Cable 2 on the device Terminal standalone 4; 3) It eliminates additional cable weight and connection points, improving system reliability; Overall working principle: This invention decouples ground testing requirements from flight configuration requirements through a modular cable branch design. The key innovation lies in: 1) Reversible design: The insertion and removal of the detachable test cable does not change the electrical characteristics and physical path of the cable on the tester; 2) Compatibility design: Connector selection ensures that the cable on the device can be directly connected to the terminal unit after disassembly; 3) Lightweight design: By removing redundant test cables, the launch weight is reduced by about 2-5 kg ​​(accounting for 1%-3% of the total weight of the micro-spacecraft).

[0040] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. A method of erecting a spacecraft detachable test cable, characterized by, The method comprises the following steps: Step 1: According to the functions and destinations of the signals arranged in the source-end single-machine electrical connector and the terminal single-machine electrical connector on the spacecraft, the signals are classified and bundled to form the on-board cable; Step 2: According to the signal properties, destinations and quantities, the signals are classified and bundled to form the detachable test cable in combination with the requirements of the signals in the terminal single-machine electrical connector being led out to the ground test equipment; Step 3: According to the timing of the ground test or launch into orbit, the detachable test cable is chained or detached to form different signal connection modes; The detachable test cable is connected with the on-board cable through a chain-in Y-type, V-type or W-type cable branch.

2. The method of claim 1, wherein, The step 1 comprises: the signals from the source-end single machine are classified and bundled according to power supply signals, data bus signals, analog signals and control instruction signals; The power supply signal bundle is used to deliver electric energy to the terminal electrical connector, the data bus signal bundle comprises digital communication signals, the analog signal bundle comprises sensor signals and monitoring signals, and the control instruction signal bundle comprises switch control signals.

3. The method of claim 2, wherein, The power supply signal bundle comprises primary power supply signals and secondary power supply signals; The data bus signal bundle comprises RS422 bus signals, CAN bus signals and 1553B bus signals; The analog signal bundle comprises temperature sensor signals, pressure sensor signals and current / voltage monitoring signals; The control instruction signal bundle comprises attitude control instructions, load switch control signals and antenna deployment control signals.

4. The method of claim 1, wherein, The step 2 comprises: the signals are classified according to signal properties into key telemetry signals, important remote control signals and power supply monitoring signals; The key telemetry signals are used for real-time monitoring, the important remote control signals are used for injection verification, and the power supply monitoring signals are used for power consumption analysis and system verification.

5. The method of claim 4, wherein, The key telemetry signals comprise attitude data and angular velocity data, the important remote control signals comprise mode switching instructions and working mode instructions, and the power supply monitoring signals comprise working current states and voltage states.

6. The method of claim 1, wherein, The step 2 further comprises: the signals are classified according to signal destinations into signals directed to a semi-physical simulation machine, signals directed to a comprehensive test bench and signals directed to a special test equipment; The signals directed to the semi-physical simulation machine comprise attitude sensor data and actuator feedback data, the signals directed to the comprehensive test bench comprise telemetry and remote control data and state monitoring data, and the signals directed to the special test equipment comprise load data and image data.

7. The method of claim 1, wherein, Each detachable test cable contains no more than 32 signal cores.

8. The method of claim 1, wherein: The electrical connector selected for the detachable test cable to be connected with the on-board cable is the same as the terminal single-machine electrical connector, and the electrical connector selected for the detachable test cable to be connected with the terminal single machine is the same as the on-board cable electrical connector.

9. The method of claim 1, wherein, The step 3 comprises: the ground test timing comprises an assembly and integrated test stage, a launch site test stage and a pre-packaging test stage, and the launch into orbit timing comprises before rocket docking and when the fairing is packaged; During ground testing, the detachable test cable is connected between the on-board cable and the terminal unit, forming a signal path through the source unit, the on-board cable, the detachable test cable branch point, the ground test equipment and the terminal unit in sequence; During launch into orbit, the detachable test cable is removed, forming a signal path through the source unit, the on-board cable and the terminal unit in sequence; The source unit is connected to the on-board cable through an electrical connector, and the terminal unit is connected to the on-board cable through an electrical connector.

10. A spacecraft detachable test cable, characterized by, The spacecraft detachable test cable is built according to any one of claims 1 to 9.

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