Spacecraft carrying device

Abstract

To provide a mechanism for changing execution contents of a sequence function of a mission to be carried out by a spacecraft after the spacecraft is launched.SOLUTION: A spacecraft mounted device 101 is mounted on a spacecraft. The spacecraft mounted device 101 includes: a first acquisition unit 111 for acquiring sequence management information 10 in which procedures of a mission to be carried out by the spacecraft are defined by a plurality of steps that continuously transition; a second acquisition unit 112 for acquiring condition management information 20 indicating transition conditions that transition from a previous step to a subsequent step in steps adjacent to each other in the transition of the plurality of steps; and a rewriting unit 113 for rewriting at least either the sequence management information 10 or the condition management information 20 while the spacecraft is staying in a space and before the spacecraft carries out the mission according to a rewriting command upon receipt of the rewriting command for commanding rewriting at least either the sequence management information 10 or the condition management information 20.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a spacecraft-mounted device, a base station device, a rewrite program, a rewrite command program, a rewrite method, and a rewrite command method. [Background technology]

[0002] When a spacecraft such as a satellite or a probe performs a mission such as rendezvous docking or landing on a celestial body, the spacecraft's control system performs navigation, guidance, control, and anomaly detection. In navigation, the position and attitude of the spacecraft are estimated using sensors. In guidance, the position and attitude of the target spacecraft are calculated. In control, actuators are controlled so that the spacecraft heads toward the guidance target. In anomaly detection, the occurrence of anomalies is monitored, and if an anomaly occurs, countermeasures are implemented.

[0003] There are multiple methods for each of navigation, guidance, control, and anomaly detection, and to achieve the mission objectives of a spacecraft, a method suitable for the mission objectives is selected before the spacecraft is launched. In this case, a sequence function is implemented in the control system of the spacecraft, and the selected method is incorporated into the sequence function (e.g., Patent Document 1). For example, when a probe gradually descends to land on a celestial body, or when a spacecraft approaches a target for rendezvous and docking, a method is selected depending on the distance to the celestial body or target.

[0004] Conventionally, the content of sequence functions is determined in the design stage before the launch of a spacecraft, so the execution content of sequence functions for mission execution cannot be flexibly changed after the launch of the spacecraft. In other words, the navigation method, guidance method, control method, or anomaly detection method defined as the execution content of sequence functions cannot be flexibly changed. Therefore, even if the need for changing the execution content of sequence functions arises based on the results of operations after launch, it is not possible to change the execution content of sequence functions, which could be a factor that prevents mission achievement. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Special Publication No. 2012-520786 Summary of the Invention [Problem to be solved by the invention]

[0006] An object of the present invention is to provide a mechanism that makes it possible to change the execution content of sequence functions of a mission to be performed by a spacecraft after the spacecraft has been launched. [Means for solving the problem]

[0007] The spacecraft-mounted device of the present invention comprises: In a spacecraft-mounted device mounted on a spacecraft moving in outer space, a first acquisition unit that acquires rewritable sequence management information in which a procedure for one of a celestial body landing and a rendezvous docking, which is a mission to be performed by the spacecraft and includes approaching a target object, is defined by a plurality of successive steps; a second acquisition unit that acquires rewritable condition management information indicating a plurality of transition conditions for transitioning from a previous step to a subsequent step between adjacent steps among the plurality of steps; A spacecraft-mounted device comprising: The sequence management information is among the plurality of steps in one mission, a navigation method to be used by the spacecraft, a guidance method to be used by the spacecraft, a control method to be used by the spacecraft, and an anomaly detection method to be used by the spacecraft are defined for each step in which a distance between the spacecraft and the target object during the approach is specified, The condition management information is In each step, a monitoring variable indicating the distance between the spacecraft and the object and a threshold value as the distance corresponding to the monitoring variable are defined, which are used to determine whether the transition condition is satisfied. [Effects of the Invention]

[0008] The spacecraft-mounted device of the present invention can provide a mechanism that allows the execution content of the sequence functions of the mission to be performed by the spacecraft to be changed after the spacecraft has been launched. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram of the first embodiment, showing a schematic external view of a spacecraft 100. [Figure 2] FIG. 1 is a diagram of the first embodiment, showing communication between a spacecraft-mounted device 101 and a base station device 201. [Figure 3] FIG. 1 is a diagram of the first embodiment, showing the hardware configuration of a spacecraft-mounted device 101. [Figure 4] FIG. 2 is a diagram of the first embodiment, showing a hardware configuration of a base station device 201. [Figure 5] FIG. 1 is a diagram according to the first embodiment, showing sequence management information 10. [Figure 6] FIG. 2 is a diagram according to the first embodiment, showing condition management information 20. [Figure 7] FIG. 1 is a diagram of the first embodiment, showing the relationship between each step of a sequence and sequence management information 10 and condition management information 20. [Figure 8] FIG. 10 is a diagram according to the first embodiment, showing the transition of sequence steps based on the condition management information 20. [Figure 9] FIG. 10 is a diagram according to the first embodiment, showing how the sequence management information 10 and the condition management information 20 are rewritten. [Figure 10] FIG. 1 is a diagram of the first embodiment, supplementing the hardware configuration of the spacecraft-mounted device 101. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In each drawing, the same or corresponding parts are designated by the same reference numerals. In the description of the embodiments, the description of the same or corresponding parts will be omitted or simplified as appropriate.

[0011] Embodiment 1 A spacecraft-mounted device 101 and a base station device 201 according to the first embodiment will be described with reference to FIGS. 1 shows a schematic view of a descending spacecraft 100. The spacecraft 100 is descending in a descent direction 103. FIG. 2 shows communication between a spacecraft-mounted device 101 and a base station device 201. The spacecraft-mounted device 101 is mounted on a spacecraft 100 moving in outer space. The spacecraft 100 is equipped with an antenna 102 that communicates with the base station device 201. The spacecraft 100 in FIG. 1 represents a probe descending to land on a celestial body 302. The base station device 201 communicates with the spacecraft-mounted device 101 mounted on the spacecraft 100 moving in outer space. The base station device 201 is located in a base station 200 provided on Earth 301. The base station device 201 communicates with the spacecraft-mounted device 101 mounted on the spacecraft 100 moving in outer space via the antenna 202.

[0012] As will be described later, before the spacecraft 100 in outer space executes the mission execution content defined by the sequence function, the base station device 201 transmits a rewrite command 201a, which is a command to change the execution content defined. The spacecraft-mounted device 101 rewrites the content of at least one of the sequence management information 10 and the condition management information 20 in accordance with the rewrite command 201a. "Rewriting the content of at least one of the sequence management information 10 and the condition management information 20 in accordance with the rewrite command 201a" has the following meaning. That is, the rewrite command 201a has command content to rewrite the content of at least one of the sequence management information 10 and the condition management information 20. If the rewrite command 201a instructs the rewrite of the sequence management information 10, the spacecraft-mounted device 101 rewrites the content of the sequence management information 10, and if the rewrite command 201a instructs the rewrite of the condition management information 20, the spacecraft-mounted device 101 rewrites the content of the condition management information 20. The sequence execution unit 114 of the spacecraft-mounted device 101 executes the sequence in accordance with the rewritten sequence management information 10 or condition management information 20, thereby changing the execution content of the sequence function of the mission to be performed by the spacecraft-mounted device 101 after the launch of the spacecraft-mounted device 101. This will be explained in detail below.

[0013] ***Configuration Description*** Fig. 3 shows the hardware configuration of the spacecraft-mounted device 101. The hardware configuration of the spacecraft-mounted device 101 will be described with reference to Fig. 3. The spacecraft-mounted device 101 is a computer. The spacecraft-mounted device 101 includes a processor 110. In addition to the processor 110, the spacecraft-mounted device 101 includes other hardware such as a main memory device 120, an auxiliary memory device 130, an input / output interface 140, and a communication interface 150. The processor 110 is connected to the other hardware via a signal line 160 and controls the other hardware.

[0014] The spacecraft-mounted device 101 includes, as functional elements, a first acquisition unit 111, a second acquisition unit 112, a rewriting unit 113, and a sequence execution unit 114. The first acquisition unit 111, the second acquisition unit 112, the rewriting unit 113, and the sequence execution unit 114 are realized by a rewriting program 501. The rewriting program 501 is stored in the auxiliary storage device 130. The processor 110 is a device that executes the rewriting program 501. The rewriting program 501 is a program that realizes the functions of the first acquisition unit 111, the second acquisition unit 112, the rewriting unit 113, and the sequence execution unit 114. The processor 110 is an IC (Integrated Circuit) that performs arithmetic processing. Specific examples of the processor 110 are a CPU (Central Processing Unit), a DSP (Digital Signal Processor), and a GPU (Graphics Processing Unit).

[0015] The primary storage device 120 is a storage device. Specific examples of the primary storage device 120 are SRAM (Static Random Access Memory) and DRAM (Dynamic Random Access Memory). The primary storage device 120 holds the results of calculations by the processor 110. The secondary storage device 130 is a storage device that stores data in a non-volatile manner. A specific example of the secondary storage device 130 is an HDD (Hard Disk Drive). The secondary storage device 130 may also be a portable recording medium such as an SD (registered trademark) (Secure Digital) memory card, a NAND flash, a flexible disk, an optical disk, a compact disk, a Blu-ray (registered trademark) disk, or a DVD (Digital Versatile Disk).

[0016] The input / output interface 140 is a port through which data is input from each device and data is output to each device. A sensor group 171 consisting of a plurality of sensors and an actuator group 172 consisting of a plurality of actuators are connected to the input / output interface 140. The communication interface 150 is a communication port through which the processor 110 communicates with other devices. A communication device 173 is connected to the communication interface 150. The processor 110 communicates with the base station device 201 via the communication interface 150 and the communication device 173.

[0017] The processor 110 loads the rewrite program 501 from the auxiliary storage device 130 into the main storage device 120, reads the rewrite program 501 from the main storage device 120, and executes it. The main storage device 120 stores not only the rewrite program 501 but also an OS (Operating System). The processor 110 executes the rewrite program 501 while executing the OS. The spacecraft-mounted device 101 may include multiple processors that replace the processor 110. These multiple processors share the execution of the rewrite program 501. Each processor is a device that executes the rewrite program 501, just like the processor 110. Data, information, signal values, and variable values ​​used, processed, or output by the rewrite program 501 are stored in the main storage device 120, the auxiliary storage device 130, or a register or cache memory in the processor 110.

[0018] The rewrite program 501 is a program that causes a computer to execute each process, procedure, or step of the first acquisition unit 111, the second acquisition unit 112, the rewrite unit 113, and the sequence execution unit 114, with the "unit" replaced with "process," "procedure," or "step."

[0019] The rewriting method is a method performed by the spacecraft-mounted device 101, which is a computer, executing the rewriting program 501. The rewriting program 501 may be provided by being stored in a computer-readable recording medium, or may be provided as a program product.

[0020] Fig. 4 shows the hardware configuration of the base station device 201. The hardware configuration of the base station device 201 will be described with reference to Fig. 4. Since the base station device 201 is also a computer similar to the spacecraft-mounted device 101, differences from the spacecraft-mounted device 101 will be described.

[0021] The base station device 201 includes a processor 210. In addition to the processor 210, the base station device 201 includes other hardware such as a main memory device 220, an auxiliary memory device 230, an input / output interface 240, and a communication interface 250. The processor 210 is connected to the other hardware via a signal line 260 and controls the other hardware.

[0022] The base station device 201 includes a command creation unit 211 and a rewrite command unit 212 as functional elements. The command creation unit 211 and the rewrite command unit 212 are realized by a rewrite command program 502. The rewrite command program 502 is stored in the auxiliary storage device 230. A communication device 273 is connected to the communication interface 250. The processor 210 communicates with the spacecraft 100 via the communication interface 250, the communication device 273, and the antenna 202. The rewrite command program 502 is a program that causes a computer to execute each process, procedure, or step in the command creation unit 211 and the rewrite command unit 212, where the "unit" is replaced with "process," "procedure," or "step." Furthermore, the rewrite command method is a method performed by the base station device 201, which is a computer, executing the rewrite command program 502. The rewrite command program 502 may be provided by being stored in a computer-readable recording medium, or may be provided as a program product.

[0023] FIG. 5 shows the sequence management information 10. Fig. 6 shows the condition management information 20. The sequence management information 10 and the condition management information 20 will be described with reference to Fig. 5 and Fig. 6. First, the sequence management information 10 will be described. The sequence management information 10 is information that defines the mission procedure to be performed by the spacecraft 100 in a plurality of successive steps. In the sequence management information 10 shown in Fig. 5, the landing sequence for landing on a celestial body is defined as steps 1 to 7 in sequence steps 11. In the sequence management information 10, the navigation method used by the spacecraft 100, the guidance method used by the spacecraft 100, the control method used by the spacecraft 100, and the abnormality detection / treatment method used by the spacecraft 100 are defined for each of the plurality of steps.

[0024] The contents of step 12 are as follows. The contents of step 1 are an approach descent to an altitude of 2000 [m]. The contents of step 2 are a descent to an intermediate target point of 300 [m] and horizontal position correction. The contents of step 3 are a descent to an altitude of 100 [m] and horizontal position maintenance. The contents of step 4 are an obstacle detection at an altitude of 100 [m] and a change of the target point. The contents of step 5 are a descent to an altitude of 10 [m]. The contents of step 6 are thruster control stopping and free fall. Step 7 is a landing sequence stop.

[0025] Navigation 13 is as follows. Navigation 13 defines the sensors used for navigation as sensors in use. In the sensors used in Navigation 13, IMU stands for inertial measurement unit, STT stands for star tracker, ALT stands for altimeter, and CAM-W stands for wide-angle camera. The parameter set used in Navigation 13 indicates the parameters that are set out of parameters A to F. The parameter sets used in Guidance 14 and Control 15 have the same meaning. Specifically, they are as follows. The sensors used in Step 1 are IMU, STT, and ALT. The sensors used in Steps 2 to 5 are IMU, STT, ALT, and CAM-W. The sensors used in Step 6 are IMU and STT. The parameter sets used for Steps 1 to 6 are A, B, C, D, E, and F.

[0026] Guidance 14 is as follows. Guidance 14 defines the guidance methods used in the landing sequence. Each guidance method defines the parameter set to be used. The guidance methods for each step are as follows. The guidance method for step 2 is altitude descent and horizontal position correction. The guidance method for step 3 is altitude descent and horizontal position hold. The guidance method for step 4 is altitude descent and horizontal position correction. The guidance method for step 5 is altitude descent and horizontal position hold. The parameter sets used for steps 2 to 5 are J, K, L, and M.

[0027] Control 15 is as follows. In Control 15, the actuators to be controlled in each step of the landing sequence are defined as actuators to be used. A parameter set is also defined for the actuators to be used. The actuators to be controlled in each step are as follows: RW indicates a reaction wheel, THR indicates a thruster, and THR*4 indicates four thrusters. The actuator to be used in Step 1 is RW. The actuators to be used in Steps 2 to 5 are RW and THR. The actuators to be used in Step 6 are RW and THR*4. The parameter sets to be used are P, Q, R, S, T, and U for Steps 1 to 6.

[0028] Anomaly detection / action 16 is as follows. Anomaly detection / action 16 defines the anomaly detection to be enabled and the action to be taken when an anomaly is detected. Anomaly detection / action 16 indicates the target of anomaly detection and the action to be taken when an anomaly is detected in the target. The anomaly detection / action for each step is as follows. Step 1 is approach descent corridor anomaly detection / abort. Steps 2 and 3 are vertical descent corridor anomaly detection / abort. Steps 4 and 5 are vertical descent corridor anomaly detection and obstacle detection / abort. Step 6 is anti-tip control during landing.

[0029] The condition management information 20 will be described with reference to Fig. 6. The condition management information 20 indicates the transition conditions for transitioning from a previous step to a subsequent step between adjacent steps among the multiple steps defined in the sequence management information 10. In the condition management information 20 of Fig. 6, for steps 1 to 7 of the sequence management information 10, the conditions for transitioning from step 1 to step 2, step 2 to step 3, step 3 to step 4, step 4 to step 5, step 5 to step 6, and step 6 to step 7 are defined as transition condition channels 1 to 6.

[0030] In the sequence management information 10, for each step k (K=1, 2, 3...6), a monitored variable 24 to be monitored and a threshold value 26 corresponding to the monitored variable 24 are defined, which are used to determine whether the transition condition from step k to step k+1 is satisfied. Specifically, in the transition condition channel 21, transition condition channels 1 to 6 are defined as transition conditions. The transition condition channel 21 is associated with the following items: a sequence transition 22, a decision operator 23, a monitored variable 24, a comparison operator 25, a threshold value 26, and a decision count 27. The condition management information 20 includes transition condition channels 1 to 6, and the sequence transition 22 to the decision count 27 defined in the transition condition channel k (k=1, 2,...6) are the transition conditions for step k in the sequence management information 10 to transition to step k+1.

[0031] A feature of the spacecraft-mounted device 101 is that, when a rewrite command 201a is received from the base station device 201 while the spacecraft-mounted device 101 is located in outer space before the execution of a mission defined in the sequence management information 10, the device 101 rewrites the contents of at least one of the sequence management information 10 and the condition management information 20 based on the rewrite command 201a. As a prerequisite for the rewrite, the operation of the spacecraft-mounted device 101 to execute a mission of a landing sequence on a celestial body using the sequence management information 10 in Fig. 5 and the condition management information 20 in Fig. 6 will be described.

[0032] 7 shows the relationship between sequence management information 10 and condition management information 20 for a sequence 104 from step 1 to step 7 of sequence step 11. As shown in FIG. 7, sequence management information 10 relates to navigation 13 to anomaly detection / treatment 16 from step 1 to step 7, and sequence management information 10 relates to the transition from step k to step k+1, where K=1, 2, 3...6.

[0033] ***Explanation of Operation*** Fig. 8 is a flowchart showing the condition management information 20 of Fig. 7. The transition of step k in the sequence management information 10 will be described with reference to Fig. 8.

[0034] <Determination process d12> It is assumed that the sequence execution unit 114 is executing step 1 of the approach descent to an altitude of 2000 [m]. In determination process d12, the sequence execution unit 114 determines whether the transition condition of transition condition channel 1 is met. That is, the sequence execution unit 114 determines whether altitude h≦2000 [m] OR time t≧3600 [s] is met. Information for this determination, as in the following determination processes, is obtained from the sensor group 171. Here, time t is the elapsed time from the start of execution of step 1. If altitude h≦2000 [m] OR time t≧3600 [s] is not met, the sequence returns to step 1. The number of determinations, as in the following determination processes, is four. If altitude h≦2000 [m] OR time t≧3600 [s] is met, the sequence transitions to step 2.

[0035] <Determination process d23> The sequence execution unit 114 descends toward the intermediate target point at an altitude of 300 [m] and executes step 2 of horizontal position correction. In determination process d23, the sequence execution unit 114 determines whether the transition condition of transition condition channel 2 is met. That is, the sequence execution unit 114 determines whether altitude h≦300 [m] is met. If altitude h≦300 [m] is not met, the sequence returns to step 2. If altitude h≦300 [m] is met, the sequence transitions to step 3.

[0036] <Determination process d34> The sequence execution unit 114 descends to an altitude of 100 [m] and executes step 3 of maintaining a horizontal position. In determination process d34, the sequence execution unit 114 determines whether the transition condition of transition condition channel 3 is satisfied. That is, the sequence execution unit 114 determines whether altitude h≦100 [m] AND −1 [deg]≦attitude angle θ≦1 [deg] is satisfied. If altitude h≦100 [m] AND −1 [deg]≦attitude θ≦1 [deg] is not satisfied, the sequence returns to step 3. If altitude h≦100 [m] AND −1 [deg]≦attitude angle θ≦1 [deg] is satisfied, the sequence transitions to step 4.

[0037] <Determination process d45> The sequence execution unit 114 detects an obstacle at an altitude of 100 m and executes step 4 of changing the target point. In determination process d45, the sequence execution unit 114 determines whether the transition condition of transition condition channel 4 is met. That is, the sequence execution unit 114 determines whether the target point change flag f1=1 is met. If the target point change flag f1=1 is not met, the sequence returns to step 4. If the destination point change flag f1=1 is established, the sequence transitions to step 5.

[0038] <Decision process d56> The sequence execution unit 114 is executing step 5 of descending to an altitude of 10 [m]. In determination process d56, the sequence execution unit 114 determines whether the transition condition of transition condition channel 5 is met. That is, the sequence execution unit 114 determines whether altitude h≦10 [m] is met. If altitude h≦10 [m] is not met, the sequence returns to step 5. If altitude h≦10 [m] is met, the sequence transitions to step 6.

[0039] <Decision process d67> The sequence execution unit 114 stops thruster control and executes step 6 of free fall. In determination process d67, the sequence execution unit 114 determines whether the transition condition of transition condition channel 6 is met. That is, the sequence execution unit 114 determines whether landing determination flag f2=1 is met. If landing determination flag f2=1 is not met, the sequence returns to step 6. If landing flag f2=1 is met, the sequence transitions to step 7, where the landing sequence stops as shown in step content 12 of FIG. 5.

[0040] 9 is a sequence diagram showing the rewriting of at least one of the sequence management information 10 and the condition management information 20. The operation of rewriting the sequence management information 10 or the condition management information 20 will be described with reference to FIG. 9. When the sequence management information 10 or the condition management information 20 is rewritten, the spacecraft-mounted device 101 is in space and has not yet executed a mission defined by the sequence management information 10 and the condition management information 20.

[0041] <Step S10> In step S10, the sequence execution unit 114 transmits operation result information 114a of the spacecraft 100 to the base station device 201 via the communication interface 150, the communication device 173, and the antenna 102. The operation result information 114a is information indicating the operation status of the spacecraft 100, and is information used by the command creation unit 211 to create the rewrite command 201a.

[0042] <Step S11> In step S11, the command creation unit 211 receives the operation result information 114a via the antenna 202, the communication device 273, and the communication interface 250. The command creation unit 211 refers to the operation result information 114a and creates a rewrite command 201a that commands the rewriting of at least one of the sequence management information 10 and the condition management information 20. In the example of FIG. 9, the command creation unit 211 creates a rewrite command 201a that commands the rewriting of both the sequence management information 10 and the condition management information 20.

[0043] <Step S12> The rewrite command unit 212 transmits the rewrite command 201a to the spacecraft 100 located in outer space via the communication device 273, thereby causing the spacecraft-mounted device 101 to rewrite at least one of the sequence management information 10 and the condition management information 20 in accordance with the rewrite command 201a. In this example, the rewrite command unit 212 causes the spacecraft-mounted device 101 to rewrite both the sequence management information 10 and the condition management information 20 in accordance with the rewrite command 201a.

[0044] <Step S13> The rewriting unit 113 of the spacecraft-mounted device 101 receives the rewriting command 201a from the base station device 201 located on the Earth 301. Specifically, the rewriting unit 113 receives the rewriting command 201a via the antenna 102, the communication device 173, and the communication interface 150.

[0045] <Step S14> The first acquisition unit 111 acquires the sequence management information 10 from the auxiliary storage device 130.

[0046] <Step S15> The second acquisition unit 112 acquires the condition management information 20.

[0047] <Step S16> The rewriting unit 113 rewrites the sequence management information 10 and the condition management information 20. For the sequence management information 10, the rewriting unit 113 rewrites the contents of at least one of the navigation 13, guidance 14, control 15, and anomaly detection / handling methods based on the rewriting command 201a. For the condition management information 20, the rewriting unit 113 rewrites at least one of the decision operator 23, the monitoring variable 24, the comparison operator 25, the threshold 26, and the number of decisions 27 based on the rewriting command 201a. That is, when the rewriting unit 113 receives the rewriting command 201a instructing the rewriting of at least one of the sequence management information 10 and the condition management information 20, the rewriting unit 113 rewrites at least one of the sequence management information 10 and the condition management information 20 in accordance with the rewriting command 201a while the spacecraft 100 is in space and before the execution of the mission. In the example of FIG. 9, the rewrite command 201a commands the rewriting of both the sequence management information 10 and the condition management information 20, so the rewrite unit 113 rewrites both the sequence management information 10 and the condition management information 20 in accordance with the rewrite command 201a.

[0048] <Step S17> The sequence execution unit 114 executes the landing sequence using the rewritten sequence management information 10 and the rewritten condition management information 20.

[0049] ***Explanation of the effect of the first embodiment*** According to the spacecraft-mounted device 101 and the base station device 201 of the first embodiment, the execution contents of the sequence functions of navigation, guidance, control, and anomaly detection of a spacecraft such as a probe can be changed while the spacecraft 100 is in space and before the spacecraft 100 executes its mission. This improves the operational flexibility of the spacecraft 100 and the possibility of accomplishing its mission.

[0050] <Hardware configuration supplement> In the spacecraft-mounted device 101 of FIG. 2, the functions of the spacecraft-mounted device 101 are realized by software, but the functions of the spacecraft-mounted device 101 may also be realized by hardware. 10 shows a configuration in which the functions of the spacecraft-mounted device 101 are realized by hardware. Note that the following description also applies to the base station device 201.

[0051] The electronic circuit 90 in FIG. 10 is a dedicated electronic circuit for realizing the functions of the first acquisition unit 111, the second acquisition unit 112, the rewriting unit 113, and the sequence execution unit 114 of the spacecraft-mounted device 101. The electronic circuit 90 is connected to a signal line 91. Specifically, the electronic circuit 90 is a single circuit, a composite circuit, a programmed processor, a parallel-programmed processor, a logic IC, a GA, an ASIC, or an FPGA. GA is an abbreviation for Gate Array. ASIC is an abbreviation for Application Specific Integrated Circuit. FPGA is an abbreviation for Field-Programmable Gate Array. The functions of the components of the spacecraft-mounted device 101 may be realized by a single electronic circuit or may be distributed and realized across multiple electronic circuits. Furthermore, some of the functions of the components of the spacecraft-mounted device 101 may be realized by electronic circuits, and the remaining functions may be realized by software.

[0052] Each of the processor 110 and the electronic circuit 90 is also called processing circuitry. In the spacecraft-mounted device 101, the functions of the first acquisition unit 111, the second acquisition unit 112, the rewriting unit 113, the sequence execution unit 114, the main memory device 120, the auxiliary memory device 130, the input / output interface 140, and the communication interface 150 may be realized by the processing circuitry.

[0053] The rewriting unit 113 of the spacecraft-mounted device 101 rewrites at least one of the sequence management information 10 and the condition management information 20 based on the rewriting command 201a transmitted from the base station device 201. However, the present invention is not limited to this. In the spacecraft-mounted device 101, the sequence execution unit 114 may generate information equivalent to the rewriting command 201a using the operation result information 114a, and the rewriting unit 113 may autonomously rewrite at least one of the sequence management information 10 and the condition management information 20 using the generated information.

[0054] In the above-described first embodiment, Fig. 1 shows a celestial body landing mission, Fig. 5 shows sequence management information 10 related to the landing sequence, and Fig. 6 shows condition management information 20 related to the landing sequence. However, these celestial body landing missions and landing sequences are just examples to which the invention according to the first embodiment is applied. The invention according to the first embodiment is not limited to celestial body landing missions, but can also be applied to various spacecraft missions, such as rendezvous and docking.

[0055] Although the first embodiment has been described above, one of the first embodiments may be partially implemented. Alternatively, two or more of the first embodiments may be partially combined and implemented. Note that the present invention is not limited to the first embodiment, and various modifications are possible as necessary. [Explanation of symbols]

[0056] 10 Sequence management information, 11 Sequence step, 12 Step content, 13 Navigation, 14 Guidance, 15 Control, 16 Anomaly detection / treatment, 20 Condition management information, 21 Transition condition channel, 22 Sequence transition, 23 Decision operator, 24 Monitoring variable, 25 Comparison operator, 26 Threshold, 27 Number of decisions, 90 Electronic circuit, 91 Signal line, 100 Spacecraft, 101 Spacecraft-mounted equipment, 102 Antenna, 103 Descent direction, 104 Sequence, 110 Processor, 111 First acquisition unit, 112 Second acquisition unit, 113 Rewrite unit, 114 Sequence execution unit, 114a Operation result information, 120 Main memory device, 130 Auxiliary memory device, 140 Input / output interface, 150 Communication interface, 160 Signal line, 171 Sensor group, 172 Actuator group, 173 Communication device, 200 base station, 201 base station device, 201a rewrite command, 202 antenna, 210 processor, 211 command creation unit, 212 rewrite command unit, 220 main memory device, 230 auxiliary memory device, 240 input / output interface, 250 communication interface, 260 signal line, 273 communication device, 301 Earth, 302 celestial body, 501 rewrite program, 502 rewrite command program.

Claims

1. In a spacecraft-mounted device mounted on a spacecraft moving in outer space, a first acquisition unit that acquires rewritable sequence management information in which a procedure for one of a celestial body landing and a rendezvous docking, which is a mission to be performed by the spacecraft and includes approaching a target object, is defined by a plurality of successive steps; a second acquisition unit that acquires rewritable condition management information indicating a plurality of transition conditions for transitioning from a previous step to a subsequent step between adjacent steps among the plurality of steps; A spacecraft-mounted device comprising: The sequence management information is among the plurality of steps in one mission, a navigation method to be used by the spacecraft, a guidance method to be used by the spacecraft, a control method to be used by the spacecraft, and an anomaly detection method to be used by the spacecraft are defined for each step in which a distance between the spacecraft and the target object during the approach is specified, The condition management information is a spacecraft-mounted device in which a monitoring variable indicating a distance between the spacecraft and the object and a threshold value as a distance corresponding to the monitoring variable are defined for each step, the monitoring variable being used to determine whether the transition condition is satisfied;

2. 2. The spacecraft-mounted device according to claim 1, wherein the sequence management information and the condition management information are rewritten when it becomes necessary to change the execution content of the sequence function after launch.

3. The sequence management information is a determination step for determining whether or not a change in a target point of the mission is required between a first distance step in which a first distance between the spacecraft and the object in the approach is defined and a second distance step which is a step subsequent to the first distance step and a step subsequent to the first distance step in which a second distance between the spacecraft and the object in the approach is defined, The determining step includes: determining whether or not the destination point needs to be changed; If it is necessary to change the target point, change the target point and perform horizontal position correction toward the changed target point while maintaining the distance specified in the first distance step; 3. The spacecraft-mounted device according to claim 1, wherein a transition to the next step of the determination step is defined if the change of the target point is not detected.

4. 4. The spacecraft-mounted device according to claim 3, wherein the determining step defines determining that a change of the target point is necessary based on the detection of an obstacle.

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