JP6157266B2 - Device for preventing erroneous detection of acceleration of re-entry machine and method for preventing erroneous detection of acceleration - Google Patents

Description

  The present invention relates to an apparatus and method for preventing erroneous detection of acceleration of a re-entry machine, and more particularly to an apparatus and method for preventing erroneous detection of acceleration of a re-entry machine that re-enters the atmosphere.

  Conventionally, spacecraft such as artificial satellites launched into outer space have been re-entered into the atmosphere when they have completed their mission and dropped into a safe area on the ground. When a spacecraft is re-entered into the atmosphere, the spacecraft body is exposed to high temperatures due to aerodynamic heating. Here, the aerodynamic heating means that the air in front of the spacecraft is compressed and the temperature rises because the spacecraft passes through the atmosphere at high speed, and the airframe is heated by the high temperature air. If the spacecraft to be re-entry does not have heat resistance against aerodynamic heating, the spacecraft re-entered into the atmosphere will be destroyed by aerodynamic heating, and a part of the aircraft will fall to the ground. For this reason, in order to return to the ground while maintaining the shape of the spacecraft, the aircraft needs to have heat resistance.

  Depending on the mission purpose of the spacecraft, for example, a re-entry machine is mounted on the spacecraft, the aerospace heating destroys the spacecraft that becomes the mother ship, the re-entry machine is separated, and the re-entry machine is dropped to the ground There is something.

  When a re-entry machine mounted on a spacecraft serving as a mother ship is re-entered into the atmosphere, an electrical interface may be prepared in advance from the spacecraft serving as a mother ship. If there is such an interface, the spacecraft will be destroyed by re-entry, and it will detect that it has been separated from the mother ship by the separation signal generated when the re-entry aircraft is separated and execute its own sequence be able to. This sequence is, for example, various controls such as imaging with a camera and parachute opening, and is very important for acquiring data on the ground and collecting a re-entry machine (non-patent) Reference 1).

"Hayabusa" that I wanted to return to the earth for any reason, [online], Japan Aerospace Exploration Agency, [searched on January 16, 2013], Internet <http://www.jaxa.jp/article/ special / hayabusareturn / kawaguchi01_e.html>

  Such a sequence is generally performed continuously based on acceleration measured by a timer and an acceleration sensor provided in the re-entry machine. This series of sequences is started before the spacecraft separates the re-entry vehicle, and the separated re-entry vehicle executes each sequence based on the acceleration accompanying falling in the atmosphere.

  The acceleration measured by the acceleration sensor includes acceleration due to the drop of the re-entry vehicle and impact acceleration generated by the destruction of the spacecraft. Since each sequence executed by the re-entry machine is performed based on the acceleration caused by the fall, there is a concern that the execution timing of each sequence may be shifted due to the impact acceleration caused by the destruction of the spacecraft. Therefore, in order to ensure that each sequence is executed at the intended timing, the re-entry machine detects acceleration after the re-entry machine detects the separation signal that separated the re-entry machine by the mother spacecraft. Had to start.

  However, if the spacecraft that is the mother ship does not have an electrical interface with the re-entry aircraft and the re-entry aircraft is separated by re-entry into the atmosphere and destroyed, the re-entry aircraft Cannot detect that it has been separated from its mother ship. For this reason, even if the re-entry machine cannot detect its separation, it has been required to execute the re-entry machine sequence at an appropriate timing.

  The present invention has been made to solve the above-described problems, and the object of the present invention is to provide a re-entry machine even when there is no electrical interface between the spacecraft as the mother ship and the re-entry machine. An object of the present invention is to provide an acceleration erroneous detection preventing apparatus for a re-entry machine capable of executing each sequence at an appropriate timing.

  In order to achieve the above-mentioned object, the acceleration error detection preventing apparatus for a re-entry machine according to claim 1 is an acceleration error detection apparatus for a re-entry machine detachably mounted on a spacecraft as a mother ship so as to re-enter the atmosphere from space. An anti-detection device, comprising: an acceleration measurement means provided in the re-entry machine for measuring acceleration of the re-entry machine; and an acceleration data acquisition means for obtaining acceleration data from the acceleration measurement means. And a control device that performs various controls of the re-entry machine based on acceleration data acquired from the acquisition means, and the control apparatus is generated when the space machine is re-entered from outer space into the atmosphere and destroyed. When the acceleration measurement means measures the impact acceleration, the acceleration data acquisition means performs a predetermined time from when the impact acceleration is measured until the influence of the impact acceleration disappears. The abort the acquisition of acceleration data from the acceleration measuring means or and controlling not to execute the determination process based on the acceleration data.

  According to a second aspect of the present invention, there is provided an apparatus for preventing erroneous detection of an acceleration of the re-entry machine, wherein the control device, as one of the various controls, has passed a predetermined time when the acceleration measuring means measures a maximum acceleration. Parachute opening means for opening the parachute later is included.

  The method for preventing erroneous detection of acceleration according to claim 3 is a method for preventing erroneous detection of acceleration of a re-entry machine that is separably mounted on a spacecraft as a mother ship so as to re-enter the atmosphere from outer space. A step of acquiring acceleration from an acceleration measuring means for measuring the acceleration of the re-entry machine, and a step of performing various controls of the re-entry machine based on the acquired acceleration. In the step of controlling, the acceleration measured by the acceleration measuring means is acquired as acceleration data by the acceleration data acquiring means, while the impact acceleration generated when the spacecraft enters the atmosphere from the space and is destroyed is When measured by acceleration measuring means, the acceleration data is acquired for a predetermined time from the time when the impact acceleration is measured until the impact acceleration is no longer affected. To stop the acquisition of acceleration data from the acceleration measuring means by stages, or and controlling not to execute the determination process based on the acceleration data.

According to the apparatus for preventing erroneous detection of re-entry aircraft according to claim 1, when the impact acceleration generated when the spacecraft as the mother ship enters the atmosphere and is destroyed is measured, the control device Control is performed so that acquisition of measured acceleration is stopped or determination processing based on acceleration is not executed over a period of time until the influence is eliminated.
As a result, there is no electrical interface between the spacecraft and the re-entry aircraft, and even if the re-entry aircraft cannot be detected by itself, the impact that occurs when the spacecraft is destroyed. It is possible to distinguish between acceleration and acceleration due to the drop of the re-entry machine. Therefore, each sequence executed by the re-entry machine can be executed at an appropriate timing based on the acceleration.

  According to the acceleration error detection preventing apparatus for a re-entry machine according to claim 2, when the maximum value of acceleration is measured, the parachute is opened after a lapse of a predetermined time. It can be softly landed on the ground or softly landed on the water surface. Accordingly, it is possible to prevent damage to an electronic device or the like mounted on the re-entry machine, so that it is possible to collect the re-entry machine or acquire data by communicating with the re-entry machine.

  According to the method of claim 3, each sequence executed by the re-entry machine can be executed at an appropriate timing based on the acceleration as in the case of the erroneous acceleration detection preventing apparatus of claim 1 described above.

It is a fragmentary sectional view of the spacecraft containing the re-entry machine of the present invention. It is a schematic block diagram of a re-entry machine. (A) is the state before the exterior of the re-entry machine is separated, (B) is the state where the exterior is separated into two, (C) is the state where the parachute is pulled out, (D) is the state where the parachute is opened FIG. It is a figure which shows the re-entry sequence of a re-entry machine. It is a figure which shows the flowchart of the acceleration erroneous detection prevention routine which concerns on this invention. It is an example of the graph of the acceleration which the acceleration sensor measured.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a partial cross-sectional view of the spacecraft 1. The spacecraft 1 is, for example, a supply machine (for example, an HTV (H-II Transfer Vehicle)) that supplies materials to an international space station (not shown). The spacecraft 1 includes a pressurizing unit 2, a non-pressurizing unit 4, a control unit 6, and a propulsion unit 8.

The pressurizing unit 2 is pressurized so that, for example, a crew member of the International Space Station can enter and work therein, and supplies (not shown) are mounted inside. A re-entry machine (acceleration erroneous detection prevention device) 12 is fixed inside the pressurizing unit 2.
In the non-pressurizing unit 4, for example, experimental equipment used outside the ship of the International Space Station, equipment for replacement, and the like are mounted inside.

The control unit 6 controls the propulsion unit 8 to perform navigation control of the spacecraft 1, power supply to equipment mounted on the spacecraft 1, communication with the ground and the international space station, and the like.
The propulsion unit 8 includes a tank (not shown) that stores a propellant, and a thruster 10 that generates a thrust by ejecting the propellant supplied from the tank as a high-speed gas. Although the thruster 10 is disposed not only on the back side of the propulsion unit 8 but also on each part of the spacecraft 1, illustration thereof is omitted.

  The re-entry machine 12 is covered with the container 13 and fixed to the pressurizing unit 2. The re-entry machine 12 is covered with a heat-resistant exterior 12a that can withstand aerodynamic heating that occurs when re-entering the atmosphere. The container 13 does not have heat resistance that can withstand aerodynamic heating that occurs when the re-entry machine 12 enters the atmosphere. For this reason, when the re-entry machine 12 is separated from the space machine 1 together with the container 13 due to the destruction of the spacecraft 1, the container 13 is also destroyed by aerodynamic heating, and only the re-entry machine 12 falls alone. Become.

  The re-entry aircraft 12 does not have an electrical interface with the spacecraft 1 that is the mother ship. For this reason, even if the spacecraft 1 is separated from the spacecraft 1 by the spacecraft 1 entering the atmosphere and being destroyed by aerodynamic heating, the re-entry machine 12 cannot receive a signal informing the separation from the spacecraft 1. .

  FIG. 2 shows a schematic configuration diagram of the re-entry machine 12. The re-entry machine 12 includes an acceleration sensor (acceleration measuring means) 14, a timer 16, a control device 18, and a parachute 20. The acceleration sensor 14 and the timer 16 are electrically connected to the control device 18. The acceleration sensor 14 inputs the measured acceleration to the control device 18. The timer 16 starts measuring time using an input signal from the control device 18 as a trigger, and notifies the control device 18 when the time specified by the control device 18 elapses.

  The control device 18 is a computer composed of a central processing unit (hereinafter referred to as a CPU), a memory (not shown) such as a ROM, a RAM, etc., and an acceleration data acquisition unit (which acquires acceleration data from the acceleration sensor 14). An acceleration data acquisition unit) 22 and a parachute opening unit (parachute opening unit) 24. Each program is stored in the memory, and the functions of the acceleration data acquisition unit 22, the parachute opening unit 24, and the like are exhibited by the control device 18 executing these programs. In addition, although the control apparatus 18 is provided with functions other than the acceleration data acquisition part 22 and the parachute opening part 24, description is abbreviate | omitted in this embodiment. The various programs stored in the memory are recorded on a storage medium (not shown) such as a hard disk, an optical disk, or a memory card. For example, the various programs are supplied from the storage medium to the memory. Is done.

  In order to reduce power consumption, the control device 18 is powered off until just before the re-entry sequence (various control) of the spacecraft 1 is started, as will be described later.

  The parachute 20 is accommodated in the re-entry machine 12, and the parachute 20 is opened when the parachute opening part 24 outputs a command signal instructing the deployment of the parachute 20. Details will be described with reference to FIGS. When the parachute opening part 24 outputs a command signal for deploying the parachute 20, the exterior 12a of the re-entry machine 12 is separated as shown in FIGS. 3 (A) and 3 (B), as shown in FIG. 3 (C). The parachute 20 accommodated in the re-entry machine 12 is pulled out, and the parachute 20 is opened as shown in FIG. Note that the re-entry machine 12 includes a configuration other than the acceleration sensor 14, the timer 16, the control device 18, and the parachute 20, but the description thereof is omitted in the present embodiment.

  Next, a re-entry sequence performed by the control device 18 of the re-entry machine 12 configured as described above will be described. 4 is a diagram showing a re-entry sequence of the re-entry machine 12, FIG. 5 is a flowchart of an acceleration erroneous detection preventing routine according to the present invention, and FIG. 6 is a graph showing an example of acceleration measured by the acceleration sensor 14. . Hereinafter, description will be made based on these drawings. In addition, the process of each step in the flowchart of the acceleration erroneous detection prevention routine described below is performed by executing a program stored in the memory of the control device 18 by the CPU.

  For example, when the acceleration sensor 14 detects that the spacecraft 1 has reached sequence A101 in FIG. 4 and has fired the thruster 10 to change the trajectory toward reentry into the atmosphere, the control device 18 automatically It is configured to turn on. When the control device 18 is turned on, an erroneous acceleration detection prevention routine is started.

  In step S1 of FIG. 5, measurement of the acceleration G of the acceleration sensor 14 is started. When the measurement of the acceleration G is started, the acceleration G measured by the acceleration sensor 14 is acquired every predetermined time and used in each step after step S2 described later.

  In subsequent step S2, it is determined whether or not the acceleration G measured by the acceleration sensor 14 exceeds a threshold value at which a predetermined acceleration is reached. As shown in FIG. 6, although the acceleration measured by the acceleration sensor 14 changes stably from the start of measurement, it changes greatly and becomes unstable like an acceleration at a certain time, that is, the time width T1. There is. For example, the main part of the spacecraft 1 serving as a mother ship starts to be destroyed by aerodynamic heating at an altitude of 78 km shown in sequence A102 of FIG. 4, and the spacecraft 1 is destroyed as shown in sequence A103, and the re-entry machine 12 This is because of the impact acceleration caused by being emitted from the spacecraft 1. If step S5 described later is executed while the acceleration is unstable like the impact acceleration, there is a possibility that it is erroneously determined that the maximum value of the acceleration has been detected. For this reason, it is determined in this step whether or not the acceleration G measured by the acceleration sensor 14 exceeds a minute impact acceleration when the spacecraft 1 starts to break, for example, 0.5 G. If the determination result is true (Yes), it is determined that the acceleration sensor 14 has measured the impact acceleration, and the process proceeds to step S3. On the other hand, if the determination result is false (No), it is determined that the impact acceleration has not been measured, and after a predetermined time has elapsed, the process returns to step S2.

  In step S3, the timer 16 starts measuring the elapsed time T in order to mask the acceleration G measured by the acceleration sensor 14 for a predetermined time. While the elapsed time T is being measured, the acceleration G measured by the acceleration sensor 14 is ignored, and the acceleration data acquisition unit 22 stops acquiring the acceleration data. Here, the specified time defined in advance is that the unstable impact acceleration caused by the destruction of the spacecraft 1 converges, that is, the influence of the impact acceleration due to the destruction of the spacecraft 1 is eliminated, and the acceleration G is stabilized. It is enough time. This time width is a width that does not reach the time Tmax when the acceleration G reaches the maximum value Gmax.

  In step S4, it is determined whether or not the elapsed time T has exceeded a predetermined time. If the determination result is true (Yes), it is determined that the impact acceleration has converged and the process proceeds to step S5. On the other hand, when the determination result is false (No), it is determined that the elapsed time T has not yet exceeded the specified time and the impact acceleration has not yet converged, and the process returns to step S4 again after a predetermined time has elapsed.

  In step S5, it is determined whether or not the acceleration G measured by the acceleration sensor 14 has reached the maximum value Gmax. Specifically, it is determined whether or not the acceleration G acquired this time is smaller than the acceleration G acquired last time. If the determination result is true (Yes), the acceleration G measured by the acceleration sensor 14 is smaller than the previously acquired acceleration G, so it is determined that the acceleration G has reached the maximum value Gmax, and the process proceeds to step S6. On the other hand, if the determination result is false (No), the acceleration G measured by the acceleration sensor 14 is equal to or greater than the previously acquired acceleration G, so that it is determined that the acceleration has not reached the maximum value, and after a predetermined time has elapsed, step S5 is performed. Return to.

  In step S6, the parachute 20 is opened after a predetermined time has elapsed from step S5. Specifically, the parachute 20 is opened after it is determined in step S5 that the acceleration G has reached the maximum value Gmax, but it is necessary to open the parachute 20 according to the required altitude. Therefore, the time required for the re-entry machine 12 to fall from the altitude at which the acceleration G measured by the acceleration sensor 14 reaches the maximum value Gmax to the required altitude is set as a predetermined time, and the timer 16 sets the predetermined time. measure. When notified from the timer 16 that a predetermined time has elapsed, the parachute 20 is opened as shown in a sequence A104.

  By opening the parachute 20, it is possible to slow down the re-entry machine 12 by slowing the falling speed of the re-entry machine 12, and the re-entry machine 12 can softly land in a safe sea area as shown in sequence A105. Thereby, it is possible to prevent the control device 18 and the like inside the re-entry machine 12 from being broken by the impact of water landing, and for example, measurement data stored in the control device 18 can be acquired via an artificial satellite. It becomes possible. In addition, when the re-entry machine 12 lands in a safe sea area, the re-entry machine 12 may include a floating mechanism for floating on the sea surface. The re-entry machine 12 may land on a safe area on land.

  As described above, in the present embodiment, when the acceleration sensor 14 measures the initial impact acceleration at which the spacecraft 1 serving as a mother ship enters the atmosphere and starts breaking with respect to the re-entry machine 12, the control device 18 The acceleration measured by the acceleration sensor 14 is ignored during the time until the impact acceleration that becomes unstable due to the destruction of the spacecraft 1 is stabilized, and the acceleration data acquisition unit 22 stops acquiring the acceleration data.

  Thereby, there is no electrical interface between the spacecraft 1 and the re-entry machine 12, and even if the separation signal separated from the spacecraft 1 by the re-entry machine 12 is not given, the impact caused by the destruction of the spacecraft 1 Can be distinguished from the acceleration caused by the drop of the re-entry machine 12. Accordingly, each process executed by the re-entry machine 12 upon re-entry can be executed at an appropriate timing based on the acceleration.

  In addition, since the parachute 20 is opened after a predetermined time has elapsed after the acceleration reaches the maximum value, the drop speed of the re-entry machine 12 can be slowed down and slowly lowered to softly land in a safe sea area. Further, it is possible to prevent the electronic device such as the control device 18 from being damaged. Therefore, the re-entry machine 12 that has landed can be collected or data can be acquired by communication.

  Although the description of the embodiment has been completed above, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the gist of the present invention.

  For example, in the above-described embodiment, the parachute 20 is opened as a sequence executed by the re-entry machine 12 re-entering the atmosphere. However, the present invention is not limited to this, and the re-entry machine 12 is provided with an imaging device, and the acceleration sensor 14 A sequence for photographing the surroundings at a desired timing may be provided based on the acceleration G measured by.

  In the above embodiment, when the acceleration G exceeds the predetermined acceleration in step S2, the predetermined time acceleration G is masked. However, if it is possible to prevent erroneous detection of the maximum acceleration value Gmax. It is not limited to this. That is, when the acceleration G exceeds a predetermined acceleration, it is only necessary to perform control so as not to execute the determination as to whether or not the acceleration in step S5 has reached the maximum value Gmax for a predetermined time.

1 Spacecraft 12 Re-entry aircraft (acceleration detection prevention device)
14 Acceleration sensor (acceleration measuring means)
18 control device 20 parachute 22 acceleration data acquisition unit (acceleration data acquisition means)
24 Parachute opening part (parachute opening means)

Claims (3)

A re-entry machine acceleration erroneous detection prevention device that is separably mounted to reenter the atmosphere from outer space to the spacecraft that is the mother ship,
An acceleration measuring means provided in the re-entry machine for measuring the acceleration of the re-entry machine;
An acceleration data acquisition means for acquiring acceleration data from the acceleration measurement means, and a control device for performing various controls of the re-entry machine based on the acceleration data acquired from the acceleration data acquisition means,
In the case where the acceleration measuring means measures the impact acceleration that occurs when the spacecraft is re-entered into the atmosphere from the outer space and is destroyed, the control device has an effect of the impact acceleration from the time when the impact acceleration is measured. Control is performed so as to stop the acquisition of acceleration data from the acceleration measurement means by the acceleration data acquisition means, or to not execute the determination process based on the acceleration data for a predetermined time until disappearance Re-entry machine acceleration erroneous detection prevention device.   The control apparatus includes parachute opening means for opening a parachute after a predetermined time when the acceleration measuring means measures maximum acceleration as one of the various controls. Device for preventing erroneous detection of acceleration of re-entry machine as described in 1. A method for preventing erroneous detection of acceleration of a re-entry machine that is separably mounted on a spacecraft to be a mother ship so as to re-enter the atmosphere from outer space,
A step of obtaining acceleration from an acceleration measuring means provided in the re-entry machine and measuring the acceleration of the re-entry machine;
And performing various controls of the re-entry machine based on the acquired acceleration,
In the step of performing various controls of the re-entry aircraft, when the acceleration measured by the acceleration measuring means is acquired as acceleration data by the acceleration data acquiring means, while the spacecraft enters the atmosphere from the space and is destroyed When the generated impact acceleration is measured by the acceleration measurement means, the acceleration data acquisition means from the acceleration measurement means for a predetermined time from when the impact acceleration is measured until the impact acceleration is no longer affected. A method of preventing erroneous detection of acceleration of a re-entry machine, characterized in that acquisition of acceleration data is stopped or determination processing based on the acceleration data is not executed.

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