Semi-physical closed-loop test system and method for optical tracking and aiming single machine

Abstract

The invention discloses a semi-physical closed-loop test system and method for an optical tracking and aiming single machine. The test system comprises the optical tracking and aiming single machine, a satellite-borne control computer, a dynamics simulator, an optical tracking and aiming single machine simulator, an analog data management computer, a telemetering display terminal computer, a database and a power supply. The testing method comprises the following steps: constructing a semi-physical closed-loop testing system, operating ground equipment and a satellite-borne control computer, outputting measurement data by the optical tracking and aiming single machine, accessing the measurement data of the optical tracking and aiming single machine to the semi-physical closed-loop testing system, and evaluating the performance of the closed-loop semi-physical testing method of the optical tracking and aiming single machine. According to the invention, the optical tracking and aiming single-machine simulator is used to verify the effectiveness of the function of the single-machine internal algorithm; meanwhile, stand-alone data are accessed to a closed loop of the control system, and the performance and robustness of the control system are fully tested.

Description

Technical Field

[0001] This invention relates to the field of spacecraft control technology, specifically to an optical tracking and aiming single-machine semi-physical closed-loop test system and method. Background Technology

[0002] As humanity continues to explore space, the number of spacecraft in orbit is increasing. Consequently, the number of spacecraft that fail due to malfunctions is also rising, occupying a significant amount of valuable orbital resources. Repairing partially malfunctioning spacecraft through on-orbit servicing, restoring their functionality, can bring substantial economic benefits; assisted deorbiting of completely malfunctioning spacecraft frees up valuable orbital resources for more important spacecraft, demonstrating broad application value.

[0003] On-orbit servicing requires operation of the target spacecraft, which necessitates the measurement of its relative position and attitude. Currently, measurements are primarily performed using optical tracking devices such as laser imaging radar, Time-of-Flight (TOF) cameras, and binocular vision cameras. These products are simple in structure, offer high measurement accuracy, and provide rapid data updates, meeting the high-precision and high-dynamic requirements of on-orbit servicing.

[0004] The approach and hovering of a spacecraft towards a target satellite requires the measurement of the relative position and attitude of the tracking and aiming unit to be incorporated into the closed loop of the control system. On-orbit optical tracking and aiming units typically operate in the ultra-close range (100m–1m), and the GNC (Spacecraft Guidance, Navigation, and Control System) semi-physical simulation system cannot provide physical targets for measurement across the entire range. To complete ground-based semi-physical closed-loop simulation tests for the entire mission, most current ground-based closed-loop tests directly relay dynamic data through the ground-based interface of the optical tracking and aiming unit, which fails to effectively verify the internal algorithmic functions of the unit. Summary of the Invention

[0005] The technical problem solved by this invention is that existing ground-based data forwarding methods cannot fully test the functionality of the internal algorithms of a single machine, as well as the performance and robustness of the single-machine data after being integrated into the closed-loop control system. To address the shortcomings of current technology, this invention provides a semi-physical closed-loop testing system and method for optical tracking and aiming single machines, capable of integrating the measured output data of optical tracking and aiming single machines into the closed-loop testing of the control system in real time.

[0006] The technical solution of this invention is: a semi-physical closed-loop testing system for an optical tracking and aiming single-unit device, comprising an optical tracking and aiming single-unit device, a spaceborne control computer, a dynamics simulator, an optical tracking and aiming single-unit device simulator, an analog data management computer, a telemetry display terminal computer, a database, and a power supply.

[0007] Optical tracking and aiming units refer to actual products such as laser imaging radar, TOF cameras, and binocular vision cameras. During operation, each unit's optical system scans or images the target spacecraft. The unit's information processing section then calculates the obtained point cloud or image data to determine the target spacecraft's relative position and attitude. In this semi-physical closed-loop test system, the optical tracking and aiming units receive the point cloud or image data output from the optical tracking and aiming unit simulator and send the calculation results to the onboard control computer.

[0008] The onboard control computer can be understood as the "brain" of the spacecraft platform. It receives the relative position and attitude information of the target spacecraft from the optical tracking unit and performs relative navigation and control calculations.

[0009] The dynamics simulator models the orbital and attitude dynamics of the spacecraft, receives control inputs from the onboard control computer, calculates the absolute and relative orbital and attitude data of the spacecraft in real time, and sends the data to the database.

[0010] The optical tracking simulator receives data from the dynamics simulator, simulates a single-machine optical system to generate corresponding point cloud or image data, and sends the data to the optical tracking simulator through the ground interface.

[0011] The analog-to-digital converter (ADC) is used in closed-loop testing to send remote control commands and unpack telemetry data, then send them to the database.

[0012] The telemetry display terminal computer extracts data from the database, including telemetry data unpacked from analog data tubes and aircraft trajectory and attitude information output by the dynamics simulator, thereby monitoring and interpreting the entire state of the closed-loop test.

[0013] The database is used to receive and record various types of data, ensuring that it can be displayed in real time and replayed later.

[0014] The power supply is used to power various stand-alone products and ground equipment.

[0015] Furthermore, the optical tracking simulator is connected to the dynamics simulator via UDP protocol, receives the absolute and relative position and attitude information of the aircraft from the dynamics simulator, as well as the time scale and solar vector direction, and simulates the single-machine optical system to generate corresponding point cloud or image data.

[0016] Furthermore, optical tracking units receive location cloud or image data output from their respective simulators via a ground survey interface, calculate relative position and relative attitude, and add corresponding time stamps.

[0017] Furthermore, the onboard control computer receives the relative position and relative attitude output by the optical tracking unit via an asynchronous 422 interface, and performs relative navigation and control calculations.

[0018] Furthermore, the dynamics simulator and analog digital management computer are connected to the onboard control computer via a reflective memory board. The dynamics simulator uses the control signals sent by the onboard computer to drive the orbital and attitude dynamics models of the spacecraft in real time. The analog digital management computer packages the remote control commands for closed-loop testing and sends them to the onboard control computer, while simultaneously receiving and unpacking the telemetry data sent by the onboard computer.

[0019] Furthermore, based on the aforementioned semi-physical closed-loop testing system for optical tracking and aiming devices, a semi-physical closed-loop testing method for optical tracking and aiming devices is implemented, comprising the following steps:

[0020] S1. Network cable connecting the dynamics simulator and the optical tracking single-machine simulator; ground cable connecting the optical tracking single-machine simulator and the optical tracking single machine; asynchronous 422 cable connecting the optical tracking single machine and the spaceborne control computer.

[0021] S2. Open the database, run the dynamics simulator, optical tracking single-machine simulator, and analog data management computer, and then run the onboard control computer. The status of the onboard computer is telemetry monitored by the telemetry display terminal computer.

[0022] S3. After the working distance of the optical tracking and aiming unit is met, the working status of the optical tracking and aiming unit is set by ground remote control or onboard computer program control, and the status of the onboard computer and the optical tracking and aiming unit is remotely monitored by the telemetry display terminal computer.

[0023] S4. The onboard control computer receives measurement information output by the optical tracking and aiming unit, uses the data to perform relative navigation and control calculations, sends the calculation results through the reflective memory board, drives the dynamics simulator in real time, and sends the telemetry data of the aircraft to the analog digital tube computer.

[0024] S5. By comparing the true values ​​of the aircraft's trajectory and attitude output by the dynamics simulator with the telemetry values ​​of the aircraft's trajectory and attitude output by the onboard computer through the telemetry display terminal computer, the accuracy of the optical tracking single-machine semi-physical closed-loop test method is assessed and evaluated.

[0025] Compared with existing technologies, the advantages of this invention are as follows: A semi-physical closed-loop testing system and method for optical tracking single-unit systems utilizes an optical tracking single-unit simulator to verify the effectiveness of the internal algorithm of the single unit; simultaneously, it integrates the single-unit data into the closed loop of the control system to fully test the performance and robustness of the control system. This overcomes the shortcomings of the ideal method of using dynamic data forwarding in ground-based semi-physical closed-loop simulation testing. Attached Figure Description

[0026] To more clearly illustrate the technical solution of the present invention, the accompanying drawings used in the description will be briefly introduced below. Obviously, the drawings described below are one embodiment of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort:

[0027] Figure 1 This is a schematic diagram of the optical tracking and aiming single-machine semi-physical closed-loop test system of the present invention;

[0028] Figure 2 This is a flowchart of the optical tracking single-machine semi-physical closed-loop test method of the present invention. Detailed Implementation

[0029] The following detailed description, in conjunction with the accompanying drawings and specific embodiments, further illustrates the solution proposed by the present invention. The advantages and features of the present invention will become clearer from the following description. It should be noted that the drawings are in a very simplified form and use non-precise proportions, used only to facilitate and clearly illustrate the embodiments of the present invention. Please refer to the drawings to make the objectives, features, and advantages of the present invention more apparent and understandable. It should be understood that the structures, proportions, sizes, etc., depicted in the accompanying drawings are only for illustrative purposes to aid those skilled in the art and are not intended to limit the implementation conditions of the present invention. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to the size, without affecting the effects and objectives achieved by the present invention, should still fall within the scope of the technical content disclosed in the present invention.

[0030] This invention provides a semi-physical closed-loop testing system and method for optical tracking and aiming single-machine systems, which solves the problem that existing ground survey data forwarding methods cannot fully test the functionality of the internal algorithms of a single machine and the performance and robustness of the single machine after data is accessed into the closed-loop control system.

[0031] A semi-physical closed-loop testing system for optical tracking single-unit cameras is shown in the attached diagram. Figure 1 This includes optical tracking and aiming single-unit computers, spaceborne control computers, dynamics simulators, optical tracking and aiming single-unit simulators, analog data management computers, telemetry display terminal computers, databases, and power supplies.

[0032] Optical tracking and aiming units refer to actual products such as laser imaging radar, TOF cameras, and binocular vision cameras. During operation, each unit's optical system scans or images the target spacecraft. The unit's information processing section then calculates the obtained point cloud or image data to determine the target spacecraft's relative position and attitude. In this semi-physical closed-loop test system, the optical tracking and aiming units receive the point cloud or image data output from the optical tracking and aiming unit simulator and send the calculation results to the onboard control computer.

[0033] The onboard control computer can be understood as the "brain" of the spacecraft platform. It receives the relative position and attitude information of the target spacecraft from the optical tracking unit and performs relative navigation and control calculations.

[0034] The dynamics simulator models the orbital and attitude dynamics of the spacecraft, receives control inputs from the onboard control computer, calculates the absolute and relative orbital and attitude data of the spacecraft in real time, and sends the data to the database.

[0035] The optical tracking simulator receives data from the dynamics simulator, simulates a single-machine optical system to generate corresponding point cloud or image data, and sends the data to the optical tracking simulator through the ground interface.

[0036] The analog-to-digital converter (ADC) is used in closed-loop testing to send remote control commands and unpack telemetry data, then send them to the database.

[0037] The telemetry display terminal computer extracts data from the database, including telemetry data unpacked from analog data tubes and aircraft trajectory and attitude information output by the dynamics simulator, thereby monitoring and interpreting the entire state of the closed-loop test.

[0038] The database is used to receive and record various types of data, ensuring that it can be displayed in real time and replayed later.

[0039] The power supply is used to power various stand-alone products and ground equipment.

[0040] Furthermore, the optical tracking simulator is connected to the dynamics simulator via UDP protocol, receives the absolute and relative position and attitude information of the aircraft from the dynamics simulator, as well as the time scale and solar vector direction, and simulates the single-machine optical system to generate corresponding point cloud or image data.

[0041] Furthermore, optical tracking units receive location cloud or image data output from their respective simulators via a ground survey interface, calculate relative position and relative attitude, and add corresponding time stamps.

[0042] Furthermore, the onboard control computer receives the relative position and relative attitude output by the optical tracking unit via an asynchronous 422 interface, and performs relative navigation and control calculations.

[0043] Furthermore, the dynamics simulator and analog digital management computer are connected to the onboard control computer via a reflective memory board. The dynamics simulator uses the control signals sent by the onboard computer to drive the orbital and attitude dynamics models of the spacecraft in real time. The analog digital management computer packages the remote control commands for closed-loop testing and sends them to the onboard control computer, while simultaneously receiving and unpacking the telemetry data sent by the onboard computer.

[0044] A semi-physical closed-loop testing method for optical tracking single-lens cameras is shown in the attached flowchart. Figure 2 The specific steps are as follows:

[0045] S1. Construction of a semi-physical closed-loop test system

[0046] Connect the different optical tracking simulators (laser imaging radar, TOF camera, and binocular vision camera) to the dynamics simulator using network cables. Connect the output port of each optical tracking simulator to its respective ground measurement port using cables, and simultaneously connect each optical tracking simulator to the asynchronous 422 interface of the onboard control computer using cables. The connections between the onboard control computer, dynamics simulator, analog data management computer, telemetry display terminal computer, and database are the same as other ground-based semi-physical closed-loop test systems and require no special handling.

[0047] In addition, power is supplied to all individual products and ground equipment via a power source.

[0048] S2, ground equipment and spaceborne control computer operation

[0049] Run the corresponding programs for the database, telemetry display terminal computer, and analog digital tube computer so that the telemetry display terminal computer can obtain data from the database and display it.

[0050] The dynamics simulator loads a dynamics program to provide the semi-physical closed-loop test system with simulations of the absolute and relative orbital and attitude motions of the aircraft. The orbital and attitude states are monitored by a telemetry display terminal computer.

[0051] Run each optical tracking simulator, configure the IP address of each simulator, and ensure normal network communication. Based on the experimental conditions of the semi-physical closed-loop test, select different target models for simulator simulation, and configure and confirm them through the simulator interface.

[0052] The onboard control computer is powered on and the program is loaded. After successful loading, it starts running and uses the analog-to-digital converter to send remote control commands to set the status of the onboard control computer. The telemetry display terminal computer monitors the telemetry status of the onboard control computer to ensure that the absolute and relative orbit, attitude settings and response status of the spacecraft are normal.

[0053] S3, Optical tracking single-unit output measurement data

[0054] After the dynamics simulation reaches the desired range for the optical tracking and aiming single-unit system, the optical tracking and aiming single-unit simulator receives the absolute and relative position and attitude information of the spacecraft, as well as the time scale and solar vector direction, from the dynamics simulator via UDP network communication. Simultaneously, based on the target model selected in S2, it simulates the single-unit optical system to generate corresponding point cloud or image data. During the simulation, the effects of sunlight, spacecraft solar panel shading, and different materials on the target spacecraft's surface on the point cloud and image are considered, resulting in more realistic point clouds or images and a more lifelike simulation. The generated point cloud or image can be viewed through the optical tracking and aiming single-unit simulator.

[0055] After confirming that the optical tracking simulator is working properly, based on the requirements of the semi-physical closed-loop test conditions, either remotely controlled from the ground or programmed by the onboard control computer, power on each optical tracking unit (laser imaging radar, TOF camera, and binocular vision camera) and set its corresponding working status. If remotely controlled from the ground, commands are sent via the analog-to-digital converter to power on the tracking unit and set its working status; if programmed by the onboard control computer, no ground operation is required.

[0056] After the optical tracking and aiming unit is powered on and outputs measurement data, the status of the optical tracking and aiming unit is monitored by the telemetry display terminal computer, including asynchronous 422 serial port acquisition and communication status, working status flag, validity and time stamp of measurement data, relative position and relative attitude, etc.

[0057] S4, Optical Tracking Single-Unit Measurement Data Input to Semi-Physical Closed-Loop Test System

[0058] Under normal asynchronous 422 serial communication between the optical tracking and aiming units and the onboard control computer, the onboard control computer can receive information such as the working status flags, validity and time stamps of measurement data, relative position, and relative attitude from each tracking and aiming unit. The onboard control computer processes and evaluates this data, selecting a suitable optical tracking and aiming unit as the reference unit. Using the relative attitude of the reference unit, it calculates the target attitude; using the relative position, it calculates relative navigation. The results of the target attitude determination and relative navigation calculations are used as input to calculate attitude and orbit control strategies. The onboard control computer sends the control strategy calculation results through a reflective memory board, driving the dynamics model of the dynamics simulator in real time and changing the spacecraft's orbit and attitude. The optical tracking simulator receives the absolute and relative position and attitude information of the aircraft sent by the dynamic simulator, as well as the time scale and solar vector direction, which will also change simultaneously. Consequently, the point cloud and image data generated by the simulator will also change in real time. The relative position and relative attitude calculated by the optical tracking simulator using the point cloud and image data output by the simulator will change accordingly, thus forming a closed-loop simulation test system.

[0059] S5 Performance Evaluation of Optical Tracking Single-Unit Closed-Loop Semi-Physical Testing Method

[0060] Through the above steps S1 to S4, an optical tracking and aiming single-unit semi-physical closed-loop testing system and method are realized. Next, the performance of this optical tracking and aiming single-unit closed-loop semi-physical testing method will be evaluated. The evaluation mainly includes the accuracy of target attitude determination, the accuracy of relative navigation, the accuracy of relative attitude control, and the accuracy of relative trajectory control.

[0061] The relative attitude, relative position, and relative velocity of the two satellites, output by the dynamics simulator, are taken as true values. The relative attitude determined by the target attitude output by the onboard control computer, and the relative position and relative velocity output by the relative navigation system, are compared with the true values ​​to evaluate the accuracy of target attitude determination and relative navigation. The control attitude angles and control attitude angular velocities output by the onboard control computer are used to evaluate the control accuracy of the relative attitude, and the difference between the output formation position velocity and the relative navigation position velocity is used to evaluate the accuracy of relative orbit control.

[0062] The aforementioned attitude and orbital states can be displayed in real-time as numerical values ​​and curves on the telemetry display terminal computer, making the performance evaluation of optical tracking single-machine semi-physical closed-loop testing methods more intuitive. If further troubleshooting is required afterward, the telemetry display terminal computer can be used to replay and analyze the data in the database.

[0063] In summary, this invention provides a semi-physical closed-loop testing system and method for optical tracking and aiming single-unit systems. It utilizes an optical tracking and aiming single-unit simulator to verify the effectiveness of the internal algorithms of the single-unit system. Simultaneously, it integrates the single-unit data into the closed loop of the control system to fully test the performance and robustness of the control system. This system can be applied to ground-based semi-physical closed-loop testing for on-orbit service missions. The test system is simple, the test method is clear and easy to implement, and it allows for quantitative performance evaluation, thus possessing significant potential for wider application.

[0064] Although the present invention has been described in detail through the preferred embodiments above, it should be understood that the above description should not be considered as a limitation of the present invention. Various modifications and substitutions to the present invention will be apparent to those skilled in the art after reading the above description. Therefore, the scope of protection of the present invention should be defined by the appended claims.

Claims

1. An optical tracking and aiming single-machine semi-physical closed-loop testing system, characterized in that, include: Optical tracking and aiming single-unit computer, spaceborne control computer, dynamics simulator, optical tracking and aiming single-unit simulator, analog digital tube computer, telemetry display terminal computer, database and power supply; The dynamics simulator simulates the orbit and attitude of the spacecraft, receives control signals from the onboard control computer, and sends the absolute and relative orbital attitude information of the spacecraft to the optical tracking single-machine simulator. The optical tracking and aiming single-machine simulator simulates a single-machine optical system to generate corresponding point cloud or image data, and sends the data to the optical tracking and aiming single machine through the ground survey interface; The optical tracking unit calculates the relative position and attitude of the target and sends the results to the onboard control calculator. The onboard control computer performs relative navigation and control calculations, and sends the control quantities to the dynamics simulator through the reflective memory board to drive the dynamics simulator, thereby forming a closed-loop control system. The analog digital management computer unpacks the telemetry data sent by the onboard control computer and sends the data to the database for storage. The telemetry display terminal computer can display telemetry data in real time from the database and replay it afterward, so as to monitor the status of the entire semi-physical closed-loop test system and analyze and troubleshoot problems.

2. The optical tracking and aiming single-machine semi-physical closed-loop testing system according to claim 1, characterized in that, The dynamics simulator models the orbital and attitude dynamics of the spacecraft, connects to the onboard control computer via a reflective memory board, and is driven by the control quantities output by the onboard control computer to calculate the absolute and relative orbital and attitude data of the spacecraft in real time, and sends the data to the database.

3. The optical tracking and aiming single-machine semi-physical closed-loop testing system according to claim 1, characterized in that, The optical tracking simulator is connected to the dynamics simulator via UDP protocol. It receives the absolute and relative position and attitude information of the aircraft from the dynamics simulator, as well as the time scale and solar vector direction, and simulates the single-machine optical system to generate corresponding point cloud or image data.

4. The optical tracking and aiming single-machine semi-physical closed-loop testing system according to claim 1, characterized in that, The optical tracking units receive location cloud or image data output by their respective simulators through the ground survey interface, calculate the relative position and relative attitude, and add the corresponding time stamps.

5. A method for optical tracking and aiming single-machine semi-physical closed-loop testing using the optical tracking and aiming single-machine semi-physical closed-loop testing system as described in claim 1, characterized in that, The steps include: setting up a semi-physical closed-loop test system, operating ground equipment and onboard control computer, outputting measurement data from optical tracking and aiming units, integrating measurement data from optical tracking and aiming units into the semi-physical closed-loop test system, and evaluating the performance of the optical tracking and aiming unit closed-loop semi-physical test method.

6. The optical tracking and aiming single-machine semi-physical closed-loop test method according to claim 5, characterized in that, In the operation steps of the ground equipment and the onboard control computer, the dynamics simulator models the absolute and relative orbits and attitudes of the spacecraft, and receives the control quantities output by the onboard control computer through the reflective memory board to form a closed-loop test.

7. The optical tracking and aiming single-machine semi-physical closed-loop test method according to claim 5, characterized in that, In the step of outputting measurement data by the optical tracking single-machine, the optical tracking single-machine simulator is connected to the dynamics simulator via UDP protocol, receives the absolute and relative position and attitude information of the aircraft from the dynamics simulator, as well as the time scale and solar vector direction, and simulates the single-machine optical system to generate corresponding point cloud or image data. After receiving the point cloud or image data output by their respective simulators, the optical tracking single machines perform relative position and relative attitude calculations.

8. The optical tracking single-machine semi-physical closed-loop test method according to claim 5, characterized in that, In the performance evaluation steps of the optical tracking single-unit closed-loop semi-physical test method, the relative attitude, relative position, and relative velocity of the two satellites output by the dynamics simulator are used as true values. The relative attitude determined by the target attitude output by the onboard control computer, and the relative position and relative velocity output by the relative navigation are compared with the true values ​​to evaluate the accuracy of target attitude determination and relative navigation. The control attitude angle and control attitude angular velocity output by the onboard control computer are used to evaluate the control accuracy of relative attitude, and the difference between the output formation position velocity and the position velocity of relative navigation are used to evaluate the accuracy of relative orbit control. The attitude and orbit states can be displayed in real time as numerical values ​​and curves through the telemetry display terminal computer, making the performance evaluation of the optical tracking single-unit semi-physical closed-loop test method more intuitive. When further troubleshooting is needed afterward, the data in the database can be replayed and analyzed using the telemetry display terminal computer.

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