JP2018144669A - Navigation system for flying object - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a navigation system for a flying object capable of accurately deriving a position and a speed of the flying object with a simple constitution using a general-purpose MPU.SOLUTION: A navigation system for a flying object to be mounted on a flying object comprises a first control unit for executing navigation processing for navigating the flying object and a second control unit having radiation resistance higher than radiation resistance of the first control unit. The second control unit determines whether or not the first control unit has stopped by monitoring predetermined processing executed by the first control unit and outputs a command signal to the first control unit for restarting the first control unit when it determines that the first control unit stopped.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an aircraft navigation system.

  Conventionally, in an environment such as space where the influence of radiation is strong, a phenomenon in which high-energy radiation enters a processor such as an MPU (Micro-processing unit) and falls into an inoperable state (hereinafter this phenomenon is referred to as a single event). ) Is known to occur easily. When such a single event occurs in an MPU mounted on a rocket or the like, a problem occurs in the operation of the rocket.

  In order to prevent the occurrence of a single event as described above, a method using a highly reliable MPU with radiation resistant design is known. In addition, a method is known in which the occurrence of a single event due to radiation is detected and the power supply to the device is switched between an on state and an off state to restore the function of the device in which the single event has occurred (patent) Reference 1). Also, a method is known in which a redundant configuration using three or more MPUs is employed to make it resistant to the influence of the occurrence of a single event (see Patent Document 2).

JP 2006-350425 A JP-T-2001-526809

  However, in the conventional technology, there is a trade-off relationship between increasing radiation resistance and reducing cost, and it is necessary to use an expensive MPU in order to provide high radiation resistance. Further, when the MPU stops functioning due to the occurrence of a single event, it is necessary to restart the MPU by transmitting a command from the ground.

  In addition, when the MPU is restarted, the data calculated and accumulated by the arithmetic processing before the restart is initialized. As a result, the data output by the arithmetic processing after the restart loses continuity with the data up to that time, and thus cannot return to the normal operation state before the restart.

  In addition, when a redundant configuration using a plurality of MPUs is employed, there is a problem that the configuration of the apparatus becomes complicated and large-scale.

  The present invention has been made in consideration of such circumstances, and provides a flying object navigation apparatus capable of accurately deriving the position and speed of a flying object with a simple configuration using a general-purpose MPU. One of the purposes is to do.

  One aspect of the present invention is a flying object navigation apparatus mounted on a flying object, the first control unit performing navigation processing for navigating the flying object, and the radiation resistance of the first control part. A second control unit having high radiation resistance, wherein a predetermined process executed by the first control unit is monitored to determine whether or not the first control unit is stopped, and the first control unit When it determines with having stopped, it is a 2nd control part which outputs the command signal for restarting a said 1st control part to a said 1st control part, The aircraft navigation apparatus provided with.

  According to one aspect of the present invention, the second control unit having higher radiation resistance determines whether or not the first control unit is stopped, and a command for restarting the first control unit if stopped. Since the signal is output, the position and speed of the flying object can be accurately derived with a simple configuration using a general-purpose MPU.

1 is a configuration diagram of an aircraft navigation system 100. FIG. 2 is a configuration diagram of a radio navigation positioning module 110. FIG. 3 is a configuration diagram of a navigation calculation module 130. FIG. It is a flowchart which shows an example of a series of processes by positioning side MPU114a. It is a flowchart which shows an example of a series of processes by positioning side FPGA114b. It is a flowchart which shows an example of a series of processes by the navigation calculation side FPGA134b. It is a flowchart which shows an example of a series of processes by navigation calculation side MPU134a. It is a figure which shows typically the flow of the process by the radio navigation positioning module 110 and the navigation calculation module 130. It is a flowchart which shows the stop determination process of MPU performed by positioning side FPGA114b and navigation calculation side FPGA134b. It is a flowchart which shows an example of the process by the navigation calculation side MPU134a when the radio wave navigation positioning module side MPU stops. It is a figure which shows typically the flow of a process by each module when the radio navigation positioning module 110 side MPU stops. It is a flowchart which shows an example of the process by the navigation calculation side FPGA134b when the navigation calculation module side MPU stops. It is a figure which shows typically the flow of the process by each module when the navigation calculation module 130 side MPU stops. It is a figure which shows typically the mode of operation | movement of the navigation calculation module 130 when the navigation calculation side MPU134a has not stopped. It is a figure which shows typically the mode of operation | movement of the navigation calculation module 130 when the navigation calculation side MPU134a has stopped. It is a figure which shows typically the mode of operation | movement of the navigation calculation module 130 when the restarted navigation calculation side MPU134a restarts a navigation calculation process.

  DESCRIPTION OF EMBODIMENTS Hereinafter, an embodiment of an aircraft navigation system of the present invention will be described with reference to the drawings. The flying object navigation apparatus is an apparatus mounted on a flying object such as a rocket, an artificial satellite, or a space probe. In the following description, the flying object is described as a rocket as an example, but may be an artificial satellite or a space probe as described above. A rocket, which is an example of a flying object, is a multi-stage rocket, for example. A satellite is stored in the uppermost stage, and the lower stages are separated from the uppermost stage and then land on the sea or land on the ground. To do. Hereinafter, the configuration and function of such an apparatus will be disclosed step by step.

[Aircraft navigation system]
FIG. 1 is a configuration diagram of an aircraft navigation system 100. The aircraft navigation apparatus 100 is connected to one or more antennas AT and the communication apparatus TM. The aircraft navigation apparatus 100 includes, for example, a radio navigation positioning module 110, an IMU (Inertial Measurement Unit) 120, a navigation calculation module 130, and a power supply module 140.

  The antenna AT receives radio waves from the outside and outputs a signal corresponding to the received radio waves (hereinafter referred to as satellite positioning signal) to an LNA (Low Noise Amplifier). The LNA amplifies the satellite positioning signal input from the antenna AT.

  The radio navigation positioning module 110 derives the position and velocity of the rocket based on the satellite positioning signal amplified by the LNA.

  The IMU 120 includes, for example, a triaxial acceleration sensor configured by MEMS (Micro Electro Mechanical Systems) or an optical fiber, and a triaxial gyro sensor. The IMU 120 outputs values detected by these sensors (horizontal, vertical, and depth accelerations, pitch, roll, and yaw rates, etc.) to the navigation calculation module 130. The IMU 120 is an example of a “detection device”.

  The navigation calculation module 130 derives the position and velocity of the rocket based on the detection value detected by the IMU 120. In addition, the navigation calculation module 130 integrates the position and velocity derived by the radio navigation positioning module 110 and the position and velocity derived using the detection result by the IMU 120 to derive the position and velocity of the rocket.

  The power supply module 140 is connected to a power supply device (not shown). The power supply module 140 includes, for example, a protection circuit and a DC-DC converter, and supplies power to each part of the aircraft navigation apparatus 100.

  The communication device TM transmits information to a ground monitoring device (not shown) using, for example, a telemeter line. For example, the ground monitoring device acquires the position and speed of the rocket after the rocket is launched (takes off) from the rocket by telemetry communication. Then, the ground monitoring device repeatedly estimates a drop point when the rocket is dropped, and transmits an instruction signal to the rocket so as to avoid danger due to the fall. In addition, if the information regarding the position and speed cannot be acquired from the rocket even after a predetermined time has elapsed, the ground monitoring device transmits a command signal for restarting the navigation system 100 for an aircraft mounted on the rocket. The communication device TM is an example of a “transmission unit”.

[Radio navigation positioning module]
FIG. 2 is a configuration diagram of the radio navigation positioning module 110. The radio navigation positioning module 110 includes, for example, a positioning-side interface 112, a positioning-side MPU 114a, a positioning-side FPGA (Field-Programmable Gate Array) 114b, an MPU-side storage unit 116a, and an FPGA-side storage unit 116b. The positioning-side FPGA 114b has a radiation resistance higher than that of the positioning-side MPU 114a, and the FPGA-side storage unit 116b has a radiation resistance higher than that of the MPU-side storage unit 116a. “With radiation resistance” means that these components are realized by, for example, processing such as increasing the gap width of the semiconductor depletion layer or increasing the spacing between wirings on the substrate. It is to make the hardware to be resistant to radiation.

  The satellite positioning signal from the antenna AT is amplified by the LNA and input to the positioning side interface 112. The positioning side interface 112 is, for example, an RF (Radio Frequency) interface and is realized by an FPGA. Note that the positioning-side interface 112 may be separate from the positioning-side FPGA 114b or may be integrated.

[MPU of radio navigation positioning module]
The positioning-side MPU 114a determines the position of the rocket by obtaining the relative distance (shoot range) from the satellite based on the satellite positioning signal corresponding to each of the radio waves received from the four or more satellites by the antenna AT. calculate. Hereinafter, this process is referred to as “position positioning”. The artificial satellite includes a quasi-zenith satellite, and the radio navigation positioning module 110 is preferably capable of performing processing corresponding to the quasi-zenith satellite.

  In addition, the positioning-side MPU 114a obtains a relative velocity with respect to each artificial satellite based on the Doppler shift of the radio waves received from four or more artificial satellites by the antenna AT, and positions the artificial satellites derived from the radio waves from the satellites. The relative velocity vector is calculated from Then, the positioning side MPU 114a corrects the calculated relative velocity vector based on the speed of the artificial satellite, and synthesizes a plurality of corrected relative velocity vectors to calculate the rocket speed (vector including speed and direction). To do. Hereinafter, this process is referred to as “Doppler positioning”.

  The positioning side MPU 114a outputs data (hereinafter referred to as satellite positioning data) including one or both of the position of the rocket calculated by position positioning and the speed of the rocket calculated by Doppler positioning to the positioning side FPGA 114b.

  The positioning-side MPU 114a accesses a first predetermined area of the FPGA-side storage unit 116b described later at a predetermined cycle (for example, 10 [Hz]), and indicates that the own apparatus (positioning-side MPU 114a) is activated. (Hereinafter referred to as error status information) is written. The first predetermined area of the FPGA-side storage unit 116b is, for example, a predetermined area of a register included in the FPGA-side storage unit 116b. Writing the error status information in the storage unit is an example of “predetermined processing”.

  In addition, the positioning-side MPU 114a accesses the second predetermined area of the FPGA-side storage unit 116b at the above-described predetermined period or a longer period, and prepares for positioning in order to restart itself (positioning-side MPU 114a). Information including the position and speed of the rocket, which is the result of the calculation, or the calculation result in the middle (hereinafter referred to as start-up reference information) is written. The second predetermined area of the FPGA-side storage unit 116b is, for example, a predetermined area of a RAM (Random Access Memory). For example, the startup reference information written by the positioning side MPU 114a includes information such as ephemeris, signal phase, or frequency. The reference information at startup is an example of “information required at restart”.

  Note that the positioning-side MPU 114a delivers (outputs) the error status information and the startup reference information to the positioning-side FPGA 114b instead of performing processing to write each of the error status information and the startup reference information in a predetermined area of the FPGA-side storage unit 116b. Thus, the positioning-side FPGA 114b may perform the writing process.

[FPGA of radio navigation positioning module]
The positioning-side FPGA 114b determines whether or not the positioning-side MPU 114a has stopped by monitoring the first predetermined area (a predetermined area of the register) of the FPGA-side storage unit 116b. For example, the positioning-side FPGA 114b determines that the positioning-side MPU 114a has stopped when new error status information has not been written until a predetermined period has elapsed since the error status information was written in the first predetermined area.

  When the positioning-side FPGA 114b determines that the positioning-side MPU 114a has stopped, the positioning-side FPGA 114b outputs a command signal (hereinafter referred to as a reboot signal) for restarting the positioning-side MPU 114a to the positioning-side MPU 114a. “Restart” may be, for example, turning off the power of the target MPU once and then turning it on again (hard reboot), or software that has been started while the power is on. (Program) may be terminated once and restarted (soft reboot).

  Further, the positioning-side FPGA 114b stores the satellite positioning data output by the positioning-side MPU 114a in the RAM of the FPGA-side storage unit 116b, reads out the satellite positioning data at a predetermined period, and outputs it to the navigation calculation module 130.

  The MPU side storage unit 116a is a storage device attached to the positioning side MPU 114a. “Accompanying” is to exclusively access the storage device. For example, the MPU-side storage unit 116a is realized by a ROM (Read Only Memory), a RAM, an EEPROM (Electrically Erasable Programmable Read Only Memory), or the like. The MPU side storage unit 116a may be realized by an HDD (Hard Disc Drive), a flash memory, or the like. The MPU-side storage unit 116a stores a program referred to by the positioning-side MPU 114a, as well as positioning satellite signals input to the positioning-side interface 112, and various calculation results (rocket position or velocity) derived by the positioning-side MPU 114a. Memorize etc.

  The supply of power to the MPU side storage unit 116a is controlled by, for example, the positioning side MPU 114a. For example, the positioning-side MPU 114a supplies the power from the power supply module 140 to the MPU-side storage unit 116a while being activated.

  The FPGA-side storage unit 116b is a storage device attached to the positioning-side FPGA 114b. For example, the FPGA side storage unit 116b is realized by a RAM (Random Access Memory) and a register. For example, the RAM of the FPGA-side storage unit 116b stores satellite positioning data and startup reference information, and the register stores error status information.

  The supply of power to the FPGA side storage unit 116b is controlled by, for example, the positioning side FPGA 114b. For example, the positioning-side FPGA 114b supplies power from the power supply module 140 to the FPGA-side storage unit 116b while being activated.

[Navigation calculation module]
FIG. 3 is a configuration diagram of the navigation calculation module 130. The navigation calculation module 130 includes, for example, a navigation calculation side MPU 134a, a navigation calculation side FPGA 134b, an MPU side storage unit 136a, and an FPGA side storage unit 136b. The navigation calculation side FPGA 134b has a higher radiation resistance than the navigation calculation side MPU 134a, and the FPGA side storage unit 136b has a higher radiation resistance than the MPU side storage unit 136a.

[MPU of navigation calculation module]
The navigation calculation side MPU 134a calculates the position of the rocket by time-integrating the speed (the speed of the rocket calculated by the Doppler positioning) included in the satellite positioning data output by the positioning side FPGA 114b during the predetermined period.

  In addition, the navigation calculation side MPU 134 a derives the position and speed of the rocket based on the detection value detected by the IMU 120. For example, the navigation calculation side MPU 134a calculates the speed by integrating the acceleration detected by the triaxial acceleration sensor of the IMU 120, and further calculates the displacement (position) by integrating the speed.

  Further, the navigation calculation side MPU 134a calculates a more accurate posture by combining displacement and direction vectors based on detection values detected by the triaxial acceleration sensor and the triaxial gyro sensor of the IMU 120.

  The navigation calculation side MPU 134a integrates the position and velocity of the rocket derived based on the detection value and satellite positioning data detected by the IMU 120 and the position and velocity of the rocket derived by the radio navigation positioning module 110, Derive the rocket position and velocity.

  For example, the navigation calculation side MPU 134a integrates both by applying a Kalman filter, for example, and derives the position and velocity of the rocket. At this time, assuming that the radio navigation positioning module 110 cannot receive satellite radio waves with the antenna AT due to the influence of multipath, or the situation where the positioning side MPU 114a described later is restarting, the navigation calculation side MPU 134a Supplements the position and speed of the rocket derived by the radio navigation positioning module 110 until immediately before with the position and speed of the rocket derived based on the detection value and satellite positioning data detected by the IMU 120.

  Then, the navigation calculation side MPU 134a outputs the information on the derived position and speed of the rocket to the navigation calculation side FPGA 134b as information (hereinafter referred to as telemetry data) for transmission to the ground monitoring device (remote location).

  Further, the navigation calculation side MPU 134a accesses the first predetermined area (for example, a predetermined area of the register) of the FPGA side storage unit 136b at a predetermined cycle (for example, 10 [ms]), and the own apparatus (navigation calculation side MPU 134a). Write error status information indicating that) is running.

  In addition, the navigation calculation side MPU 134a accesses the second predetermined area (for example, a predetermined area of the RAM) of the FPGA side storage unit 136b at the above-described predetermined period or a longer period, and the own apparatus (navigation calculation side) In preparation for the restart of the MPU 134a), start-up reference information including various calculation results is written. For example, the startup reference information written by the navigation calculation side MPU 134a includes information such as attitude quaternions.

  The navigation calculation side FPGA 134b may perform the process of writing the error status information or the startup reference information in the predetermined area of the FPGA side storage unit 116b instead of the navigation calculation side MPU 134a.

[FPGA of navigation calculation module]
The navigation calculation side FPGA 134b acquires the information output by the radio navigation positioning module 110 and outputs the information to the navigation calculation side MPU 134a. Further, the navigation calculation side FPGA 134b acquires the detection value output by the IMU 120 and outputs it to the navigation calculation side MPU 134a.

  Further, the navigation calculation side FPGA 134b transmits information on the position and speed of the rocket output as telemetry data by the navigation calculation side MPU 134a to the ground monitoring device using the communication device TM.

  Further, the navigation calculation side FPGA 134b determines whether or not the navigation calculation side MPU 134a has stopped by monitoring the first predetermined area of the FPGA side storage unit 136b. For example, the navigation calculation side FPGA 134b determines that the navigation calculation side MPU 134a has stopped when no new error status information has been written until the predetermined period has elapsed since the error status information was written in the first predetermined area. To do.

  When the navigation calculation side FPGA 134b determines that the navigation calculation side MPU 134a is stopped, the navigation calculation side FPGA 134b outputs a reboot signal for restarting the navigation calculation side MPU 134a to the navigation calculation side MPU 134a.

  The navigation calculation side FPGA 134b converts the satellite positioning data into a predetermined data format when the satellite navigation data is output by the radio navigation positioning module 110 while the navigation calculation side MPU 134a is restarted. The transmitted data is transmitted as telemetry data to the ground monitoring device using the communication device TM. The predetermined data format format is, for example, a format such as a serial communication format.

  The MPU side storage unit 136a is a storage device attached to the navigation calculation side MPU 134a. For example, the MPU side storage unit 136a is realized by a ROM, a RAM, an EEPROM, or the like. Further, the MPU side storage unit 136a may be realized by an HDD, a flash memory, or the like. The MPU side storage unit 136a stores a program referred to by the navigation calculation side MPU 134a, and stores a processing result by the navigation calculation side MPU 134a.

  The supply of power to the MPU side storage unit 136a is controlled by, for example, the navigation calculation side MPU 134a. For example, the navigation calculation-side MPU 134a supplies power from the power supply module 140 to the MPU-side storage unit 136a while being activated.

  The FPGA-side storage unit 136b is a storage device attached to the navigation calculation-side FPGA 134b. For example, the FPGA-side storage unit 136b is realized by a RAM and a register. For example, the RAM of the FPGA side storage unit 136b stores satellite positioning data output from the radio navigation positioning module 110, telemetry data output from the navigation calculation side MPU 134a, and the register stores error status information.

  The supply of power to the FPGA side storage unit 136b is controlled by, for example, the navigation calculation side FPGA 134b. For example, the navigation calculation-side FPGA 134b supplies the power from the power supply module 140 to the FPGA-side storage unit 136b while being activated.

[Processing flow]
Hereinafter, processing of each module will be described. FIG. 4 is a flowchart illustrating an example of a series of processes performed by the positioning-side MPU 114a that is the MPU of the radio navigation positioning module 110. The processing of this flowchart is repeatedly performed at a predetermined cycle, for example. Hereinafter, in the figure, “MDL” indicates a module.

  First, the positioning-side MPU 114a waits until a satellite positioning signal is input from the positioning-side interface 112 (step S100), and when the satellite positioning signal is input, starts a positioning calculation process (step S102). The positioning calculation process is to perform one or both of the position positioning and the Doppler positioning described above. The positioning calculation process is an example of “navigation process”.

  Next, the positioning side MPU 114a outputs the satellite positioning data (A in the figure) obtained by the positioning calculation process to the positioning side FPGA 114b (step S104).

  Next, the positioning-side MPU 114a determines whether or not a predetermined period (a period corresponding to a predetermined period) has elapsed (step S106). If the predetermined period has elapsed, the first predetermined area of the FPGA-side storage unit 116b. (Register), write error status information (step S108), access to the second predetermined area (RAM) of the FPGA side storage unit 116b, and as a part of information of the positioning calculation processing result, ephemeris, signal phase Alternatively, startup reference information including information such as frequency is written (step S110). Note that the writing of the error status information and the writing of the reference information at startup may be performed at different timings. Thereby, the process of this flowchart is complete | finished.

  FIG. 5 is a flowchart showing an example of a series of processing by the positioning-side FPGA 114b that is the FPGA of the radio navigation positioning module 110. The processing of this flowchart is repeatedly performed at a predetermined cycle, for example.

  First, the positioning-side FPGA 114b waits until satellite positioning data (A in the figure) is input from the positioning-side MPU 114 (step S200). When the satellite positioning data is input, this is, for example, stored in the RAM of the FPGA-side storage unit 116b. (Step S202).

  Next, the positioning-side FPGA 114b reads the satellite positioning data (B in the figure) from the RAM of the FPGA-side storage unit 116b at a predetermined cycle, and outputs this to the navigation calculation module 130 (step S204). Thereby, the process of this flowchart is complete | finished.

  FIG. 6 is a flowchart showing an example of a series of processing by the navigation calculation side FPGA 134b which is the FPGA of the navigation calculation module 130. The processing of this flowchart is repeatedly performed at a predetermined cycle, for example.

  First, the navigation calculation side FPGA 134b waits until satellite positioning data (B in the figure) is input from the radio navigation positioning module 110 (step S300), and when the satellite positioning data is input, for example, the FPGA side storage unit It is stored in the RAM 136b (step S302).

  Next, the navigation calculation side FPGA 134b reads the satellite positioning data (C in the figure) from the RAM of the FPGA side storage unit 136b at a predetermined cycle, and outputs this to the navigation calculation side MPU 134a (step S304).

  Next, the navigation calculation side FPGA 134b determines whether or not telemetry data (D in the figure) is input from the navigation calculation side MPU 134a (step S306). When the telemetry data is input, for example, the FPGA side storage unit It is stored in the RAM 136b (step S308).

  Next, the navigation calculation side FPGA 134b reads the telemetry data from the RAM of the FPGA side storage unit 136b at a predetermined cycle, and transmits the read telemetry data to the ground monitoring device using the communication device TM (step S310). Thereby, the process of this flowchart is complete | finished.

  FIG. 7 is a flowchart showing an example of a series of processes by the navigation calculation side MPU 134a which is the MPU of the navigation calculation module 130. The processing of this flowchart is repeatedly performed at a predetermined cycle, for example.

  First, the navigation calculation side MPU 134a determines whether or not the satellite positioning data (C in the figure) is input from the navigation calculation side FPGA 134b (step S400), and starts the navigation calculation process when the satellite positioning data is input. (Step S402). The navigation calculation processing is the above-described (1) processing for deriving the position and speed of the rocket based on the detection value detected by the IMU 120, and (2) time integration of the speed included in the satellite positioning data. (3) a process of integrating the position and speed of the rocket derived based on the detected value of the IMU 120 and the satellite positioning data, and the position and speed of the rocket derived by the radio navigation positioning module 110; To do some or all of the above. The navigation calculation process is another example of the “navigation process”.

  Next, the navigation calculation side MPU 134a outputs the result of the navigation calculation process (information on the position and speed of the rocket) (D in the figure) to the navigation calculation side FPGA 134b as telemetry data (step S404).

  Next, the navigation calculation-side MPU 134a determines whether or not a predetermined period (a certain period corresponding to a predetermined period) has elapsed (step S406), and when the predetermined period has elapsed, the first predetermined value in the FPGA-side storage unit 136b. Access an area (register), write error status information (step S408), access a second predetermined area (RAM) of the FPGA-side storage unit 136b, and use information such as attitude quaternion as part of the navigation calculation processing result The startup reference information including the information is written (step S410). Note that the writing of the error status information and the writing of the reference information at startup may be performed at different timings.

  FIG. 8 is a diagram schematically showing the flow of processing by the radio navigation positioning module 110 and the navigation calculation module 130. As illustrated, satellite positioning data is output from the positioning side MPU 114a, which is the MPU of the radio navigation positioning module 110, to the positioning side FPGA 114b, which is the FPGA of the radio navigation positioning module 110 (A in the figure). The positioning-side FPGA 114b outputs the satellite positioning data to the navigation calculation-side FPGA 134b that is the FPGA of the navigation calculation module 130 at a predetermined cycle (for example, 10 [Hz]) (B in the figure).

  The navigation calculation side FPGA 134b which is the FPGA of the navigation calculation module 130 outputs the satellite positioning data input from the radio navigation positioning module 110 to the navigation calculation side MPU 134a which is the MPU of the navigation calculation module 130 (C in the figure).

  The navigation calculation side MPU 134a derives the position and velocity of the rocket based on the satellite positioning data output from the navigation calculation side FPGA 134b and the detected value detected by the IMU 120, and the derived result is used as telemetry data on the navigation calculation side. The data is output to the FPGA 134b (D in the figure).

  The navigation calculation side FPGA 134b transmits the telemetry data output by the navigation calculation side MPU 134a to the ground monitoring device using the communication device TM.

  Further, the positioning-side MPU 114a periodically writes error status information to the FPGA-side storage unit 116b that accompanies the positioning-side FPGA 114b and is exclusively accessed by the positioning-side FPGA 114b (X in the figure).

  Further, the navigation calculation side MPU 134a periodically writes the error status information to the FPGA side storage unit 136b which is attached to the navigation calculation side FPGA 134b and exclusively accessed by the navigation calculation side FPGA 134b (Y in the figure).

  In response to the writing of the error status information, the FPGA that is an accompanying source of each storage unit performs a determination process for determining whether or not the MPU is stopped.

  FIG. 9 is a flowchart showing MPU stop determination processing performed by the positioning-side FPGA 114b and the navigation calculation-side FPGA 134b. The processing in this flowchart is processing for monitoring each FPGA-side storage unit and determining whether each MPU is stopped. This flowchart is repeatedly performed at a predetermined cycle, for example. Hereinafter, the positioning side FPGA 114b will be described as an example, but the same processing may be performed for the navigation calculation side FPGA 134b.

  First, the positioning-side FPGA 114b determines whether or not error status information has been written in the first predetermined area of the FPGA-side storage unit 116b (in the case of the navigation calculation-side FPGA 134b, the first predetermined area of the FPGA-side storage unit 136b) ( Step S500) When the error status information is not written, it is determined whether or not a predetermined time has passed (Step S502).

  When the predetermined time has elapsed without writing the error status information, the positioning-side FPGA 114b determines that the positioning-side MPU 114a has stopped (step S504). For example, the positioning side MPU 114a and the navigation calculation side MPU 134a have lower radiation resistance than the positioning side FPGA 114b and the navigation calculation side FPGA 134b. Therefore, as the rocket is launched and approaches the sky, it becomes more susceptible to radiation and single events are more likely to occur. When a single event occurs and each MPU stops, the update of error status information is interrupted. Therefore, as described above, each FPGA monitors the writing of the error status information, and determines that the positioning-side MPU 114a has stopped if the error status information has not been updated for a certain period of time.

  If the positioning-side FPGA 114b determines that the positioning-side MPU 114a has stopped, the positioning-side FPGA 114b outputs a reboot signal for restarting the positioning-side MPU 114a (step S506). As a result, the MPU determined to have been stopped (MPU having a high probability of being stopped) is restarted.

  When each MPU stops, the processing by each MPU is suspended until it is restarted and returned. Therefore, the modules on the side where the MPU has not stopped perform the following processing.

[Processing flow of the navigation calculation module when the MPU on the radio navigation positioning module side is stopped]
FIG. 10 is a flowchart showing an example of processing by the navigation calculation MPU 134a when the radio navigation positioning module MPU is stopped.

  First, the navigation calculation side MPU 134a determines whether or not satellite positioning data has been received from the radio navigation positioning module 110 via the navigation calculation side FPGA 134b (step S600). Then, it is determined whether or not a predetermined time has elapsed (step S602).

  When the satellite positioning data is not received and the predetermined time has elapsed, the navigation calculation side MPU 134a determines that the radio wave navigation positioning module side MPU (positioning side MPU 114a) is stopped (step S604).

  Next, the navigation calculation side MPU 134a is used when integrating the position and speed of the rocket derived based on the detection value of the IMU 120 and the satellite positioning data, and the position and speed of the rocket derived by the radio navigation positioning module 110. Update of the observed value of the Kalman filter is stopped (step S606). The observed value is an error between the position and speed of the rocket derived from the detected value of the IMU 120 and the satellite positioning data and the position and speed of the rocket derived from the radio navigation positioning module 110 (that is, position error and speed error). It is. This stops the integration of position and velocity. Note that the update of the observation value of the Kalman filter may be resumed in response to the restart of the positioning side MPU 114a.

  Next, the navigation calculation side MPU 134a starts the navigation calculation process in a state where the integration of position and velocity is stopped (step S608). That is, the navigation calculation side MPU 134a does not use the position and speed of the rocket derived by the radio navigation positioning module 110, but uses the information on the position and speed of the rocket derived based on the detected value of the IMU 120 as the telemetry data. The data is output to the calculation side FPGA 134b (step S610). Thus, even when the MPU on the radio navigation positioning module 110 side is stopped, the position and speed of the rocket can be continuously derived only by the MPU on the navigation calculation module 130 side that is not stopped.

  FIG. 11 is a diagram schematically showing a flow of processing by each module when the radio navigation positioning module 110 side MPU is stopped. As shown in the example, when error status information is not written in the register of the FPGA side storage unit 116b for a predetermined time or more, the positioning side FPGA 114b restarts the positioning side MPU 114a when it is determined that the positioning side MPU 114a is stopped. A reboot signal for causing the signal to be output is output to the positioning side MPU 114a (R in the figure). As a result, the radio navigation positioning module 110 side MPU is restarted.

  While the MPU on the radio navigation positioning module 110 is restarted, the satellite navigation data is not output from the radio navigation positioning module 110 to the navigation calculation module 130. In this case, the navigation calculation side MPU 134a outputs information on the position and speed of the rocket derived based on the detection value of the IMU 120 to the navigation calculation side FPGA 134b as telemetry data without performing the speed and position integration processing (FIG. Medium D).

  At this time, the navigation calculation-side MPU 134a periodically writes error status information to the FPGA-side storage unit 136b that accompanies the navigation calculation-side FPGA 134b and is exclusively accessed by the navigation calculation-side FPGA 134b (Y in the figure). The navigation calculation side FPGA 134b may be notified that the own aircraft is not stopped.

  The navigation calculation side FPGA 134b transmits the telemetry data output by the navigation calculation side MPU 134a, that is, information on the position and speed of the rocket derived based on the detection value of the IMU 120 to the ground monitoring device using the communication device TM.

[Processing flow of the navigation calculation module when the MPU on the navigation calculation module is stopped]
FIG. 12 is a flowchart showing an example of processing by the navigation calculation side FPGA 134b when the navigation calculation module side MPU stops. This process may be performed in parallel with the process of the flowchart shown in FIG. That is, the navigation calculation side FPGA 134b may determine that the navigation calculation side MPU 134a has stopped, and perform the processing of the following flowchart separately from the processing of outputting the reboot signal.

  First, the navigation calculation side FPGA 134b waits until satellite positioning data is input from the radio navigation positioning module 110 (step S700). When the satellite positioning data is input, the satellite positioning data is converted into a predetermined data format. Thus, telemetry data is generated (step S702).

  Next, the navigation calculation side FPGA 134b stores the generated telemetry data in, for example, the RAM of the FPGA side storage unit 136b (step S704).

  Next, the navigation calculation side FPGA 134b reads the telemetry data from the RAM of the FPGA side storage unit 136b at a predetermined cycle, and transmits the read telemetry data to the ground monitoring device using the communication device TM (step S706). Thereby, even when the MPU on the navigation calculation module 130 side is stopped, the position and speed of the rocket can be continuously derived only by the MPU of the radio navigation positioning module 110 that is not stopped.

  FIG. 13 is a diagram schematically showing the flow of processing by each module when the MPU on the navigation calculation module 130 side is stopped. As shown in the example, when error status information is not written in the register of the FPGA-side storage unit 136b for a predetermined time or more, the navigation calculation-side FPGA 134b determines that the navigation calculation-side MPU 134a has stopped, and the navigation calculation-side MPU 134a. Is output to the navigation calculation side MPU 134a (R in the figure). As a result, the MPU on the navigation calculation module 130 side is restarted.

  If the MPU on the radio navigation positioning module 110 is not stopped while the MPU on the navigation calculation module 130 side is restarted, satellite positioning data is output from the radio navigation positioning module 110 to the navigation calculation module 130. In this case, as described above, the navigation calculation side FPGA 134b converts the satellite positioning data output from the radio navigation positioning module 110 into a predetermined data format to generate telemetry data, for example, the FPGA side storage unit It is stored in the RAM 136b (T in the figure). Then, the navigation calculation side FPGA 134b reads the satellite positioning data converted into the predetermined data format from the RAM, and transmits it to the ground monitoring device using the communication device TM.

[Write process of reference information at startup]
The startup reference information writing process by the MPU on the navigation calculation module 130 side will be described below. FIG. 14 is a diagram schematically showing the operation of the navigation calculation module 130 when the navigation calculation side MPU 134a is not stopped. As in the illustrated example, the navigation calculation side FPGA 134b acquires the detected values (acceleration and rate of each dimension) detected by the IMU 120 and outputs them to the navigation calculation side MPU 134a. In response, the navigation calculation side MPU 134a performs navigation calculation processing. Then, when a single event does not occur and the navigation calculation side MPU 134a does not stop, the navigation calculation side MPU 134a writes the startup reference information in the RAM of the FPGA side storage unit 116b attached to the navigation calculation side FPGA 134b. The startup reference information in this case includes, for example, information such as attitude quaternion as described above.

  FIG. 15 is a diagram schematically showing the operation of the navigation calculation module 130 when the navigation calculation side MPU 134a is stopped. As shown in the figure, while the navigation calculation side MPU 134a is stopped, the navigation calculation side FPGA 134b obtains the detected value detected by the IMU 120 and does not output it, for example, stores it in the RAM of the FPGA side storage unit 136b. Let me. As a result, the detection value detected by the IMU 120 during the MPU stop period can be accumulated in the FPGA-side storage unit 136b.

  FIG. 16 is a diagram schematically showing the operation of the navigation calculation module 130 when the restarted navigation calculation side MPU 134a resumes the navigation calculation processing. As shown in the figure, the navigation calculation side MPU 134a is restarted after receiving the reboot signal, and outputs the startup reference information written in the RAM of the FPGA side storage unit 136b before the restart and the navigation calculation side FPGA 134b. The detection values of the IMU 120 stored in the RAM of the FPGA-side storage unit 136b are read out, and the navigation calculation process is restarted based on the startup reference information and the detection values of the IMU 120. Thereby, the navigation calculation side MPU 134a can update the attitude, position, and speed of the rocket that should have been originally during the time zone when the MPU was stopped. As a result, it is possible to eliminate the attitude angle error, the position error, and the speed error caused by stopping the update process during the MPU return process. Note that the navigation calculation side MPU 134a does not use the past acceleration detected by the IMU 120 during the time period from when the reboot signal is received to restart, but the acceleration (current acceleration) sequentially detected by the IMU 120 and the stop time period. The navigation calculation process may be restarted using the past rate detected by the IMU 120 (the rate accumulated in the RAM during the stop period).

  According to the embodiment described above, the radio navigation positioning module 110 or the navigation calculation module 130 is an MPU that performs navigation processing for navigating a rocket, and an FPGA that has a radiation resistance higher than the radiation resistance of the MPU. Monitoring the writing of error status information executed by the MPU to determine whether or not the MPU has stopped. If it is determined that the MPU has stopped, the FPGA that outputs a reboot signal to the MPU to restart the MPU By providing, the position and speed of the flying object can be accurately derived with a simple configuration using a general-purpose MPU.

  Further, according to the above-described embodiment, the MPU of each module stores the startup reference information as information required at the time of restart in the storage device on the FPGA side, and reads the startup reference information after the restart. Since the process is resumed, a re-restoration process that ensures data continuity can be performed.

  Further, according to the above-described embodiment, in each module, the MPU having a relatively low radiation resistance and the FPGA having a high radiation resistance operate in a coordinated manner. Therefore, the flying object navigation apparatus 100 can have a simple configuration.

  In the embodiment described above, in each module, the FPGA determines whether or not the MPU has stopped by monitoring error status information written in the storage unit on the FPGA side by the MPU. However, the present invention is not limited to this. . For example, the MPU may count the number of times of error correction processing of various data generated in its own device, and if the counted number exceeds a threshold value, a signal for requesting restart may be output to the FPGA. In this case, the FPGA outputs a reboot signal to the MPU in response to the output restart request signal. The output of a signal for requesting restart is another example of “predetermined processing”.

  As mentioned above, although the form for implementing this invention was demonstrated using embodiment, this invention is not limited to such embodiment at all, In the range which does not deviate from the summary of this invention, various deformation | transformation and substitution Can be added.

AT ... antenna, 100 ... aircraft navigation device, 110 ... radio navigation positioning module, 112 ... positioning side interface, 114a ... positioning side MPU, 114b ... positioning side FPGA, 116a ... MPU side storage unit, 116b ... FPGA side storage unit 120 ... IMU, 130 ... Navigation calculation module, 134a ... Navigation calculation side MPU, 134b ... Navigation calculation side FPGA, 136a ... MPU side storage unit, 136b ... FPGA side storage unit, 140 ... Power supply module, TM ... Communication device

Claims (7)

A navigation device for an aircraft mounted on an aircraft,
A first control unit that performs navigation processing for navigating the flying object;
Whether or not the second control unit has a radiation resistance higher than that of the first control unit, and the first control unit is stopped by monitoring a predetermined process executed by the first control unit. A second control unit that outputs a command signal for restarting the first control unit to the first control unit when it is determined that the first control unit is stopped;
Aircraft navigation device comprising: The first control unit is an MPU, and the second control unit is an FPGA.
The aircraft navigation apparatus according to claim 1. A storage unit associated with the second control unit;
The first controller is
Of the processing results of the navigation processing, at least information necessary for restarting is written in the storage unit,
After restarting in response to a command signal from the second control unit, restarting the navigation process based on the information written in the storage unit before restarting,
The aircraft navigation system according to claim 1 or 2. The first control unit periodically writes predetermined information to the storage unit as the predetermined process,
The second control unit determines that the first control unit is stopped when the predetermined information is not written to the storage unit for a predetermined period.
The aircraft navigation apparatus according to claim 3. A radio navigation positioning module having the first control unit and the second control unit;
A navigation calculation module having the first control unit and the second control unit;
A detection device for detecting an inertial force acting on the flying object,
The first controller on the radio navigation positioning module side is:
Deriving the position and velocity of the aircraft based on radio waves coming from the satellite,
The second control unit on the radio navigation positioning module side is
The first derivation result by the first control unit on the radio navigation positioning module side is transmitted to the navigation calculation module,
The second control unit on the navigation calculation module side is
Receiving the first derivation result from the second control unit on the radio navigation positioning module side;
The first control unit on the navigation calculation module side is:
Based on the detection result by the detection device, the position and velocity of the flying object are derived,
Integrating the first derivation result received by the second control unit on the navigation calculation module side and the second derivation result using the detection result by the detection device to derive the position and velocity of the flying object;
The aircraft navigation apparatus according to any one of claims 1 to 4. A transmission unit for transmitting information on the position and velocity of the flying object derived by the first control unit on the navigation calculation module side to a remote place;
The second control unit on the navigation calculation module side receives the first derivation result received from the second control unit on the radio navigation positioning module side when the first control unit on the navigation calculation module side stops. , Convert to a predetermined data format,
The transmitting unit transmits the first derivation result converted into a predetermined data format to the remote place instead of transmitting information on the position and velocity of the flying object.
The navigation apparatus for an aircraft according to claim 5. The second control unit on the navigation calculation module side is
When the first control unit on the navigation calculation module side stops, the command signal is output to the first control unit on the navigation calculation module side,
Until the first control unit on the navigation calculation module side restarts, the detection result by the detection device is written in the storage unit attached to the second control unit,
The first control unit on the navigation calculation module side is:
Of the integration results of the first derivation result and the second derivation result, at least information necessary for restarting is written in the storage unit,
Based on the detection result written in the storage unit and the information written in the storage unit before restarting after receiving a command signal from the second control unit on the navigation calculation module side and restarting Resume the process of deriving the position and velocity of the vehicle,
The navigation apparatus for an aircraft according to claim 5 or 6.

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