KR102154246B1 - Satellite and the method for analyzing its software time - Google Patents

Abstract

The present invention relates to an artificial satellite and a method of analyzing the execution time of the software thereof, and more particularly, to a method of measuring the execution time of the software of the artificial satellite through hardware.
The method of measuring software execution time of an artificial satellite of the present invention includes performing at least one task, recording a start time and an end time of at least one task in hardware, and recording in hardware And generating execution time data for at least one task and storing execution time data based on the set start time and end time.

Description

Satellite and its software execution time analysis method {SATELLITE AND THE METHOD FOR ANALYZING ITS SOFTWARE TIME}

The present invention relates to an artificial satellite and a method of analyzing the execution time of the software thereof, and more particularly, to a method of measuring the execution time of the software of the artificial satellite through hardware.

Today, satellites are being launched into space for a variety of purposes and missions. These satellites are equipped with software to achieve their purpose and mission. The software installed on the satellite manages and controls all the states and motions of the satellite, and is essential for performing the satellite's original mission.

The software of these satellites must satisfy real-time, which will affect the safety and performance of the satellite. Satisfaction with real-time performance can be achieved when a given task is completed within a limited time according to a predetermined schedule.

In general satellites, a clock counter is implemented in which the value increases sequentially according to the system reference clock. The software uses this clock counter to measure the execution time for each minor cycle. With a typical telemetry period (geostationary satellites: 10 minor cycles = 1 second, LEO satellites: 8 minor cycles = 1 second), the result is transferred to the ground. Difficult to transmit Accordingly, conventionally, a separate method such as Minor Cycle Sampling (MCS) was applied to transmit the data to the ground.

However, conventionally, there was a problem in that the MCS method was used to secure storage space as many as the number of minor cycles, and a delay occurred in the process of calculating each execution time by the software, and unnecessary complexity of the software. There has been a problem that this is caused.

The present invention is in accordance with the necessity for solving the above-described problems, and one problem to be solved by the present invention is that the software mounted on the satellite does not need to check the count values of the start and end times of the execution time, It tells you to provide a simplified software by accessing the address of the hardware.

According to an embodiment of the present invention, a method for measuring execution time of software of an artificial satellite may include performing at least one task; Recording a start time and an end time of the at least one task in hardware; Generating execution time data for the at least one task based on the start time and end time recorded in the hardware; And storing the execution time data.

In addition, the recording may be to record the start time and end time of the first task by accessing the first address of the hardware when is performed on the first task among the at least one task. have.

In addition, the recording may include accessing the second address of the hardware and performing the second task when a second task having a type and a minor cycle different from the first task among the at least one task is performed. It may be to record the start time and end time of the task.

In addition, the generating may be to generate a telemetry frame including the start time and end time as the execution time data based on a telemetry generation rule.

In addition, the execution time measurement method may further include transmitting the stored execution time data to the ground.

Meanwhile, the method of measuring the execution time of software for an artificial satellite using a computer according to an embodiment of the present invention may use a computer program stored in a medium to execute the above-described method.

On the other hand, the satellite according to an embodiment of the present invention includes a memory; And a processor; wherein the processor performs at least one task, records a start time and an end time of the at least one task in hardware, and the start time recorded in the hardware And execution time data for the at least one task may be generated based on an end time, and the execution time data may be stored in the memory.

In addition, the processor may access a first address of the hardware and record a start time and an end time of the first task when is performed on the first task among the at least one task.

In addition, when a second task having a type and a minor cycle different from the first task among the at least one task is performed, the processor accesses the second address of the hardware Start time and end time can be recorded.

In addition, the processor may generate a telemetry frame including the start time and end time as the execution time data based on a telemetry generation rule. .

In addition, the satellite may further include a communication unit, and the processor may control the communication unit to transmit the stored execution time data to the ground.

Other aspects, features, and advantages other than those described above will become apparent from the following drawings, claims, and detailed description of the invention.

According to the present invention, the software can be simplified by only informing the hardware of the start and end times, and additional processing for time measurement is reduced.

In addition, a separate method such as Minor Cycle Sampling (MCS) was used to transmit the time measurement data to the ground. However, by using the present invention, the existing telemetry processing method can be applied as it is. It becomes easy to implement and operate.

1 is a block diagram illustrating a configuration included in an artificial satellite according to an embodiment of the present invention.
2 is a diagram for explaining how a conventional satellite software measures a task execution time using a counter.
3 is a diagram showing a minor cycle sampling (MCS) method for transmitting a result of measuring an execution time of a conventional satellite software.
4 is a diagram for describing a method of measuring a software execution time of an artificial satellite according to an embodiment of the present invention.

Hereinafter, various embodiments of the present document will be described with reference to the accompanying drawings. However, this is not intended to limit the techniques described in this document to specific embodiments, and it should be understood that various modifications, equivalents, and/or alternatives of the embodiments of this document are included. In connection with the description of the drawings, similar reference numerals may be used for similar elements.

In addition, expressions such as "first," "second," etc. used in this document can modify various elements regardless of their order and/or importance, and to distinguish one element from other elements. It is used only and does not limit the components. For example, a first user device and a second user device may represent different user devices regardless of order or importance. For example, without departing from the scope of the rights described in this document, a first component may be referred to as a second component, and similarly, a second component may be renamed to a first component.

Some component (eg, a first component) is "(functionally or communicatively) coupled with/to)" to another component (eg, a second component) or " When referred to as "connected to", it should be understood that the certain component may be directly connected to the other component, or may be connected through another component (eg, a third component). On the other hand, when a component (eg, a first component) is referred to as being “directly connected” or “directly connected” to another component (eg, a second component), the component and the It may be understood that no other component (eg, a third component) exists between the different components.

Terms used in this document are only used to describe a specific embodiment, and may not be intended to limit the scope of other embodiments. Singular expressions may include plural expressions unless the context clearly indicates otherwise. Terms used herein, including technical or scientific terms, may have the same meaning as commonly understood by one of ordinary skill in the technical field described in this document. Among the terms used in this document, terms defined in a general dictionary may be interpreted as having the same or similar meanings as those in the context of the related technology, and unless explicitly defined in this document, an ideal or excessively formal meaning Is not interpreted as. In some cases, even terms defined in this document cannot be interpreted to exclude embodiments of this document.

Hereinafter, various embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram illustrating a configuration of an artificial satellite according to an embodiment of the present invention. In the present invention, the'artificial satellite' may be various devices that move in a three-dimensional space. For example, an artificial satellite may be a device that transmits and receives data to and from a ground station while orbiting or moving around the Earth and/or other planets. In this case, the satellite may be mounted on a launch vehicle and launched through the launch pad. In this case, software according to a predetermined purpose and/or purpose may be mounted on the satellite.

In addition, the satellite may be a flying vehicle in the atmosphere according to a predetermined purpose and/or use. In this case, the satellite can take off and/or land without a launch vehicle and/or launch pad. However, this is an example and the spirit of the present invention is not limited thereto.

The satellite according to an embodiment of the present invention may transmit a signal to a ground station at predetermined time intervals. In other words, the satellite can transmit signals to the ground station at a certain period of time. For example, a satellite can transmit a signal to a ground station every 5 seconds.

In this case, a signal transmitted by the satellite to the ground station is telemetry, and may be transmitted in a frame and/or packet unit. Accordingly, the satellite can transmit frames and/or packets to the ground station at predetermined time intervals.

The frame and/or packet transmitted by the satellite to the ground station may include information on the sequence number of the frame and/or packet. For example, in the case of a frame and/or packet that the satellite sends to the ground station for the tenth time, information for identifying that the frame and/or packet is transmitted for the tenth time may be included in the frame and/or packet.

Of course, in addition to the above-described sequence number information, the frame and/or packet may further include various data (eg, data related to the state of the satellite) according to a predetermined rule and/or standard.

The satellite according to an embodiment of the present invention includes a processor 100 including a telemetry processing unit 150, a clock counter 110, a time measurement unit 120, a result recording unit 130, and a telemetry. A generator 140 and a setting unit 160 may be included.

The clock counter 110 is a counter whose value increases by 1 every tick according to the system reference clock. Specifically, the tick may be determined at a preset time interval, or may be determined based on a system event for the system to control an operation. The clock counter 110 may increase the counter value by 1 whenever a preset tick passes, and the processor 100 may acquire the execution time of software based on the counter value.

When receiving a signal from software performed by the processor 100, the time measurement unit 120 may perform time measurement through the clock counter 110 and transmit the result value to the result recording unit 130.

The result recording unit 130 is a device that records the measurement result transmitted from the time measurement unit 120 according to a predetermined method, and may manage recording according to a task type, a minor cycle order, and the like.

The telemetry generation unit 140 is a device that generates data for telemetry processing according to a request of software from time measurement data stored in the result recording unit.

The setting unit 160 is a configuration for setting and storing various basic data necessary for processing such as time measurement and recording, data format, etc., and the basic data value may be a preset value, but may be changed by the processor 100 for each situation. have.

1 shows that the clock counter 110, the time measurement unit 120, the result recording unit 130, the telemetry generation unit 140, and the setting unit 160 are implemented as separate devices. The devices of may be implemented as a single device. In other words, the plurality of devices (110, 120, 130, 140, 160) may be separate devices physically separated into individual or partial sets, or any one of a separate application, process, or task driven by the same processor. May be. However, in the following description, for convenience of description, it is assumed that a plurality of devices are separate devices.

Meanwhile, the telemetry processing unit 150 may be included in the processor 100. The telemetry processing unit 150 may be a software component for software execution in the processor 100.

The telemetry processing unit 150 requests and obtains a record of a task execution result in the processor 100 from the telemetry generation unit 140, and records the result in a frame to be transmitted to the ground. In this case, the frame to be transmitted to the ground may be a telemetry frame including time information at which a specific address of hardware is accessed when software execution starts or ends.

When performing a task through software, the processor 100 according to an embodiment of the present invention may transmit a signal indicating start and end to the time measurement unit 120. For example, the processor 100 may transmit a start signal to the time measurement unit 120 when executing the software task 1 170, and the time measurement unit 120 uses the clock of the clock counter 110 The start time of task 1 170 may be acquired. In addition, the processor 100 may transmit an end signal to the time measurement unit 120 when the software task 1 170 ends, and the time measurement unit 120 uses the clock of the clock counter 110 to transmit the software task 1 It is possible to obtain the end time of (170). This is also the case when the processor 100 performs software task 2 180 different from software task 1 170.

In this case, the processor 100 may refer to a data processing device embedded in hardware having a circuit physically structured to perform a function represented by a code or command included in a program. As an example of such a data processing device built into the hardware, a microprocessor, a central processing unit (CPU), a processor core, a multiprocessor, and an application-specific integrated (ASIC) Circuit) and processing devices such as a Field Programmable Gate Array (FPGA) may be covered, but the scope of the present invention is not limited thereto.

For example, the processor 100 may include RAM, ROM, and a system bus. Here, the ROM is a configuration in which the instruction set for booting the system is stored, and the CPU copies the operating system stored in the memory (not shown) to RAM according to the instruction stored in the ROM, and executes O/S to boot the system. When booting is complete, the CPU can perform various operations by copying various applications stored in the memory to RAM and executing them.

In the above, it has been described that the processor 100 includes only one CPU, but when implemented, it may be implemented with a plurality of CPUs (or DSP, SoC, etc.).

Meanwhile, although not shown in FIG. 1, the satellite of the present invention may further include a memory and a communication unit.

In particular, the memory records the time when the execution of software starts or ends in a specific address value allocated by the processor 100, or based on time information recorded in other components, according to an embodiment of the present invention. You can save the created data. In this case, the generated data may be data for ?remetry processing including a time at the time of start or end. That is, the memory may include the result recording unit 130, but is not limited thereto and may be implemented in a separate configuration.

The memory may store various data for overall operation of the satellite, such as a program for processing or controlling the processor 100. The memory may store a plurality of application programs (application programs or applications) driven by the satellite, data for operation of the satellite, and instructions. At least some of these application programs may be downloaded from an external server through wireless communication. In addition, at least some of these application programs may exist on the satellite from the time of manufacture for basic functions of the satellite. The application program may be stored in a memory and driven by the processor 100 to perform an operation (or function) of an artificial satellite.

The memory may be implemented in the form of Semi-Global-Matching (SGM) or TCM. However, the present invention is not limited thereto, and the memory may be implemented as a nonvolatile memory, a volatile memory, a flash-memory, a hard disk drive (HDD), or a solid state drive (SSD). The memory is accessed by the processor 100, and data read/write/edit/delete/update by the processor 100 may be performed. In the present disclosure, the term memory may include memory, ROM, RAM, or an attachable memory card (not shown) (eg, micro SD card, memory stick) in the processor 100.

On the other hand, the communication unit is a configuration for transmitting and receiving signals with a ground station on the ground. Specifically, the satellite may transmit a telemetry frame including information on the execution time of software generated by the satellite to the ground station through the communication unit.

In the present invention, a ground station (not shown) may refer to a device that transmits and receives signals to and from an artificial satellite, analyzes the state of the satellite from telemetry received from the satellite, and controls the satellite based thereon. Accordingly, the ground station may include an antenna for transmitting and receiving signals and an antenna driver for adjusting the angle of the antenna. Of course, the ground station may further include a processor or the like in addition to the above-described configuration.

Meanwhile, the processor 100 according to an embodiment of the present invention may be provided separately from the above-described satellite and ground station. For example, the satellite may include a processor (not shown) that controls other components as a whole, and may include a processor 100 for measuring the execution time of software as a separate component.

2 is a diagram for explaining how a conventional satellite software measures a task execution time using a counter.

Referring to FIG. 2, the software obtains a counter value at the start and end of a task to measure time using a clock counter, and can measure execution time by using the difference between these two values. .

Specifically, the satellite's software can perform a task in each minor cycle. That is, the software may record the execution start time of the first task 210 during the first sub-period and record the execution end time. The software can calculate the elapsed time by processing the recorded start and end times. That is, by the above-described method, the software may measure the execution time 211 that the first task was performed during the first minor cycle. Similarly, the software may measure the execution time 221 of the second task 220 during the first minor cycle.

That is, the satellite's software can measure the execution time (211, 212, 213, 221, 222, 223) for each task in each minor cycle and generate a minor cycle frame. have.

However, as described above, when the software records and calculates the execution start time and end time for each task to measure the execution time, it is implemented relatively more complicated than the case of performing the process and simply notifying the execution start and end. Should be.

In addition, it is difficult to transmit the result to the ground with the conventional telemetry period (geostationary satellite: 10 minor cycles = 1 second, low orbit satellite: 8 minor cycles = 1 second). Accordingly, conventionally, as shown in FIG. 3, a separate method such as Minor Cycle Sampling (MCS) was applied to transmit the data to the ground.

3 is a diagram showing a minor cycle sampling (MCS) method for transmitting a result of measuring an execution time of a conventional satellite software.

Referring to FIG. 3, the satellite software may include 10 minor cycles for 1 second. For example, the satellite software includes 10 minor cycles for N seconds to N+1 seconds, and accordingly, D0 to D9, 10 tasks can be performed.

Conventional satellite software samples the measurement results for tasks for each minor cycle in a minor cycle sampling (MCS) data frame and transmits the results to the ground without omission.

In other words, when MCS (minor cycle sampling) is processed and transmitted to the ground, a storage space must be separately allocated for each minor cycle in order to prevent deletion of a result value according to an initial minor cycle. That is, according to the conventional method, there is a disadvantage in that an excessively large amount of storage space may be consumed.

4 is a diagram for describing a method of measuring a software execution time of an artificial satellite according to an embodiment of the present invention.

Referring to FIG. 4, the processor 100 may execute a start command 410 to transmit a first task start signal from the satellite software to hardware. In this case, the hardware may be a separate component from the processor 100 for driving software, such as the time measurement unit 120. However, the present invention is not limited thereto, and the hardware may be a component other than a component for executing software among components included in the processor 100.

When receiving the first task execution start signal through the start command 410, the hardware may acquire the start time through the counter value of the clock counter 110. Thereafter, the processor 100 may access a specific address of the result recording unit 130 corresponding to the first task through a read or write method. The processor 100 may control the telemetry generation unit 140 to record a time at which the satellite software starts performing the first task in a frame based on the access time. In this case, the frame may be data for telemetry processing for transmission from a satellite to the ground, but is not limited thereto.

In other words, the processor 100 may record a counter value of a clock counter corresponding to an access time to a specific address of hardware. Here, the clock counter may be a counter whose value increases by 1 every 1 tick according to the system reference clock. That is, the processor 100 may acquire a software execution start time by reading a specific address of the hardware corresponding to the first task or recording it through a counter value at the time of reading or writing.

Meanwhile, the processor 100 may execute a termination command 411 for the satellite software to perform the first task. In addition, when the satellite software finishes performing the first task, the processor 100 may execute a command 412 to transmit a first task termination signal from the satellite software to hardware. When receiving the end signal for performing the first task through the end command 412, the processor 100 may read or write a specific address of the result recording unit 130 corresponding to the first task. The processor 100 may acquire an access time to a specific address of hardware, and through the access time, the software of the satellite may record the end time of performing the first task in a frame.

Thereafter, when the next minor cycle starts, the processor 100 may immediately execute a start command 410 for performing the first task (S413).

Also, the processor 100 may perform the same process for the second task. That is, the processor 100 may execute a start command 420 for notifying the start of the second task, a command 421 for executing the second task, and a termination command 422 for notifying the end of the second task. . In addition, the processor 100 may record the start and end times of performing the second task in a frame by accessing a specific address of the hardware in response to the start and end signals of the second task. Similarly, when the next minor cycle starts, the processor 100 may execute a start command 420 for performing the second task (S423). In this case, the processor 100 may perform the first task and the second task in the same sub-period, or may perform simultaneously.

That is, when performing a task in one minor cycle, the processor 100 may transmit only signals for starting and ending additional calculation process software to hardware (a time measuring unit in this embodiment). Accordingly, there is an effect that the satellite software of the present invention can efficiently perform tasks without an additional computational part.

In the above description, only the processor 100 performs the first task and the second task, but this is only an example, and two or more tasks may be simultaneously performed during the same minor cycle.

Further, the present invention is not limited thereto, and the processor 100 may manage recording according to the type of task and the order of minor cycles. Specifically, the processor 100 may separate and manage different types of tasks by recording them in different addresses of hardware. In this case, the hardware may be the result recording unit 130, but is not limited thereto.

Further, the processor 100 may write to the same address of hardware for the same task in different minor cycles. That is, when the task is the same for a plurality of minor cycles, the processor 100 may record visual information of the result of each minor cycle in the same address. Thereafter, the satellite may transmit telemetry information generated based on information stored in the corresponding address value to the ground. Accordingly, through the present invention, for a plurality of the same tasks within the same telemetry transmission period, there is an effect that the storage space can be efficiently used without losing execution time information. However, this is only an exemplary embodiment, and the processor 100 may separately record different values by reading or writing different values to one hardware address for different tasks.

According to an embodiment of the present invention, the processor 100 may set various basic data necessary for processing, such as time measurement and recording, and data format. The preset basic data may be changed when performing a task of software.

According to another embodiment of the present invention, the processor 100 may terminate the measurement of the task execution time by inputting a hardware time that is a reference such as RTC or 1 PPS as an input. In addition, the processor 100 may process telemetry data in a preset manner and initialize to start measuring a new task execution time.

In addition, although the preferred embodiments of the present invention have been illustrated and described above, the present invention is not limited to the specific embodiments described above, and the technical field to which the present invention belongs without departing from the gist of the present invention claimed in the claims. In addition, various modifications are possible by those of ordinary skill in the art, and these modifications should not be individually understood from the technical spirit or prospect of the present invention.

Therefore, the spirit of the present invention is not limited to the embodiments described above, and not only the claims to be described later, but also all ranges equivalent to or equivalently changed from the scope of the present invention. It will be said to belong to.

100: processor
110: clock counter
120: time measurement unit
130: result record book
140: Telemetry generator
150: telemetry processing unit
160: setting unit

Claims (10)

In an artificial satellite for measuring the execution time of software mounted on the satellite using hardware,
Communication department;
A result recording unit including a hardware address corresponding to at least one task and recording an access time of the hardware address;
When at least one task is started or terminated by executing software, and a first task among the at least one task is started or terminated, a first hardware address corresponding to the first task is accessed, and the at least one task When starting or ending a second task among the tasks, the processor accesses a second hardware address corresponding to the second task;
A time measuring unit for acquiring an access time for the processor to access the result recording unit by using a counter value of a clock counter increasing by one tick according to a system reference clock; And
Including; a telemetry generating unit for generating telemetry data for the at least one task based on the frame in which the access time is recorded, and
The time measurement unit,
The processor starts the first task to obtain a first access time for accessing the first hardware address, and ending the first task to obtain a second access time for accessing the first hardware address, and the Starting a second task to obtain a third access time for accessing the second hardware address, ending the second task to obtain a fourth access time for accessing the second hardware address,
The result recording unit records the first access time to the fourth access time,
The telemetry generation unit generates telemetry data by recording the first access time to the fourth access time recorded in the result recording unit in the frame,
The communication unit is an artificial satellite that transmits the telemetry data to the ground. delete delete The method of claim 1,
The telemetry generating unit generates a telemetry frame including a start time and an end time as the telemetry data based on a telemetry generation rule. The method of claim 1,
The time measurement unit, the result recording unit, the telemetry generation unit, and the result recording unit are implemented as a separate hardware chip different from the processor. In the satellite's software (software) execution time measurement method,
Starting or ending a first task among at least one task by executing software, by a processor, and accessing a first hardware address on a result recording unit corresponding to the first task;
A time measurement unit obtains a first access time for accessing the first hardware address by starting the first task, and obtaining a second access time for accessing the first hardware address by ending the first task Step to do;
Starting or ending a second task among at least one task by executing software, by a processor, and accessing a second hardware address on the result recording unit corresponding to the second task;
A time measurement unit obtains a third access time for accessing the second hardware address by starting the second task, and obtaining a fourth access time for accessing the first hardware address by ending the first task Step to do;
Generating telemetry data by recording the first to fourth access times in a frame; And
Transmitting the telemetry data to the ground; A method of measuring a running time comprising a. delete delete The method of claim 6,
In the generating step, a telemetry frame including a start time and an end time is generated as the telemetry data based on a telemetry generation rule. A computer program stored in a recording medium to execute the method of any one of claims 6 and 9 using a computer.

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