Strong real-time high-speed attitude measurement information guarantee method

Abstract

The invention discloses a strong real-time high-speed attitude measurement information guarantee method, and relates to the technical field of inertial equipment attitude measurement information guarantee, and the method comprises the following steps: taking time code information of a whole ship time reference as absolute time, and completing inertial navigation attitude information timestamp synchronization by using a synchronization pulse per second of the time reference; determining a target frequency according to an interpolation requirement, and linearly interpolating a data packet sent by the inertial device into data of the target frequency; and after the data of the target frequency is converted into an optical signal, information is transmitted through optical waves, so that strong real-time transmission of high-speed attitude measurement information is realized. According to the invention, an attitude measurement data packet time synchronization method, a high-speed attitude measurement information interpolation method and an information transmission method are designed, the update rate and strong real-time transmission of attitude reference measurement information are greatly improved through a software and hardware combined design mode, and strong real-time high-speed attitude information guarantee for important reference users such as shipborne radars is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of attitude measurement information guarantee for inertial devices, and particularly relates to a method for guaranteeing strong real-time and high-speed attitude measurement information. Background Art

[0002] With the application of various high-precision devices on ships, the accuracy requirements for the navigation reference information of the ship platform are increasing day by day. When the navigation attitude reference information provided by the main inertial navigation is transmitted to the user equipment, it will be affected by hull angular deformation, time delay, platform movement, etc. When the hull deformation between the main inertial navigation and the user equipment is large, a local reference is usually configured near the installation location of the user equipment. After the initial alignment of the local reference is completed by means of inertial transfer alignment, the local reference provides local attitude measurement information to the user equipment. This method can effectively solve the influence of hull deformation and the like between the main inertial navigation and the user equipment on the transmission of the attitude reference, but the cost of configuring a dedicated local reference is relatively high; when the hull deformation between the inertial navigation and the user equipment is relatively small, most user equipment chooses to directly use the attitude measurement information of the main inertial navigation as the relevant calculation reference. In this case, the navigation reference transmission error caused by time delay and platform movement, etc. (the influence of time delay on the navigation reference transmission means that after the main inertial navigation completes the measurement of the reference information, it needs to go through certain time delays in processing, transmission and other links before it can be sent to the user equipment. If the user directly uses this information, the attitude change caused by the movement of the ship platform will be superimposed) becomes the key link to be solved.

[0003] In view of the increasing demand for reference accuracy of navigation users who directly use the attitude measurement information of the main inertial navigation and the limited update rate of the output data of the main inertial navigation, it is necessary to develop a method for strongly real-time and high-speed guarantee of the attitude measurement information of the main inertial navigation, so as to minimize the navigation reference transmission error caused by time delay and platform movement, etc., and effectively improve the guarantee level of the navigation attitude reference information. Summary of the Invention

[0004] In view of the increasing demand for reference accuracy of navigation users and the limited update rate of the attitude measurement information of the main inertial navigation, the embodiment of the present invention proposes a method for guaranteeing strong real-time and high-speed attitude measurement information, designs a time synchronization method for attitude measurement data packets, a high-speed interpolation method for attitude measurement information and an information transmission method, and through a combination of software and hardware design, greatly improves the update rate of attitude reference measurement information and strong real-time transmission, and realizes the strong real-time and high-speed attitude information guarantee for important reference users such as shipborne radars.

[0005] In a first aspect, the present invention provides a method for guaranteeing strong real-time and high-speed attitude measurement information, including: Taking the time code information of the ship-wide time reference as the absolute time, and using the synchronous second pulse of the time reference to complete the time stamp synchronization of the inertial navigation attitude information; Determine the target frequency according to the interpolation requirement, and linearly interpolate the data packets sent by the inertial device into data of the target frequency; After converting the data of the target frequency into an optical signal, transmit information through the optical wave to achieve strong real-time transmission of high-speed attitude measurement information.

[0006] In some instances, using the time code information based on the ship-wide time reference as the absolute time, and completing the timestamp synchronization of the inertial navigation attitude information by using the synchronous second pulse of the time reference, includes: Using the navigation information processing board containing DSP and FPGA in the master inertial navigation, introduce the data packets sent by the inertial device and the PPS second pulse information of the time reference into the navigation information processing board, and the attitude information is included in the data packets; The FPGA in the navigation information processing board is triggered by the rising edge of the second pulse, latches the data packet closest to the second pulse nearby, and transmits the latched data packet and the delay between the data packet and the second pulse to the serial port of the DSP for parsing; The DSP synchronously parses the whole-second data packets latched by the FPGA and the time code information of the time reference device, and calculates the time difference between the Beijing time and the running time of the inertial navigation; When the DSP receives a data packet, if the running time of the inertial navigation in the data packet is parsed, the corresponding timestamp is obtained from the time difference between the Beijing time and the running time of the inertial navigation.

[0007] In some instances, calculate the time difference Δt between the Beijing time and the running time of the inertial navigation by Δt = t1 - t2 + Δt1 + Δt2, where t1 is the Beijing time in the time code information, t2 is the running time of the inertial navigation device in the data packet, Δt1 is the delay between the data packet and the second pulse, and Δt2 is the delay error caused by the transmission from the generation of data by the inertial device to the transmission to the navigation information processing board.

[0008] In some instances, obtain the corresponding timestamp t1′ by t1′ = Δt + t2′, where t2′ is the running time of the inertial navigation in the data packet.

[0009] In some instances, the step of determining the target frequency according to the interpolation requirement and linearly interpolating the data packets sent by the inertial device into data of the target frequency, includes: Determine the target frequency according to the interpolation requirement, and use the quartz crystal oscillator built in the FPGA to generate an interrupt of the target frequency; Each time the interrupt is triggered, obtain the time difference from the nearest data packet, and perform interpolation based on the time difference.

[0010] In some instances, the step of determining the target frequency according to the interpolation requirement, includes: The maximum roll amplitude allowed in sea conditions is R 0, the minimum roll period is Tr, and the maximum pitch amplitude under the allowable sea state is P 0 , the minimum pitch period is T p ; For the attitude reference transfer error links caused by user latency and platform movement, the roll requirement is R′ and the pitch requirement is P′, and the frequency of the master inertial navigation attitude measurement information is G 0 , the target frequency of the master inertial navigation attitude measurement information required by the user is G 1 ; Then: R 0 / (Tr * G 1 ) ≤ R′, P 0 / (Tp * G 1 ) ≤ P′.

[0011] In some instances, the interpolated pitch P2, roll R2, and heading H2 are respectively: P2 = P1 + PV1 * Δt′, R2 = R1 + RV1 * Δt′, H2 = H1 + HV1 * Δt′, where Δt′ is the time difference between each interruption trigger and the nearest data packet, P1 is the pitch parsed from the data packet sent by the inertial device, R1 is the roll parsed from the data packet sent by the inertial device, H1 is the heading parsed from the data packet sent by the inertial device, PV1 is the pitch angular rate parsed from the data packet sent by the inertial device, RV1 is the roll angular rate parsed from the data packet sent by the inertial device, and HV1 is the heading angular rate parsed from the data packet sent by the inertial device.

[0012] In some instances, after converting the data of the target frequency into an optical signal, the information is transmitted through light waves, including: Select fiber optic communication to convert the data of the target frequency into an optical signal through an optoelectronic conversion module, and then transmit the information through light waves to achieve strong real-time transmission of high-speed attitude measurement information.

[0013] In some instances, the optoelectronic conversion module includes a transmitter, a fiber optic interface, a repeater, and a receiver connected in sequence.

[0014] Generally speaking, compared with the prior art, the above technical solutions conceived by the present invention can achieve the following beneficial effects: Applying this method to the attitude measurement information guarantee design of the master inertial navigation device, the update rate of the master inertial navigation attitude measurement information is improved through interpolation. On this basis, the fiber optic communication module method is adopted to meet the strong real-time high-speed attitude information guarantee requirements of attitude reference users such as radar. The present invention is not limited to the surface ship navigation system and can be used and promoted to other information systems with similar processes. Description of the Drawings

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those skilled in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0016] Figure 1 It is a schematic diagram of a strong real-time high-speed attitude measurement information guarantee method provided by an embodiment of the present invention; Figure 2 It is a schematic diagram of the attitude information timestamp acquisition process provided by an embodiment of the present invention; Figure 3 It is a schematic diagram of the attitude information interpolation process provided by an embodiment of the present invention; Figure 4 It is a schematic diagram of the fiber optic communication composition provided by an embodiment of the present invention. Detailed implementation manners

[0017] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present invention.

[0018] In the following description, specific embodiments of the present invention will be described with reference to steps and symbols executed by one or more computers, unless otherwise specified. Therefore, these steps and operations will be mentioned several times as being executed by a computer. As used herein, computer execution includes operations of a computer processing unit that represents electronic signals in a structured form of data. This operation transforms the data or maintains it at a position in the computer's memory system, which can be reconfigured or otherwise changed in a manner well known to those skilled in the art. The data structure maintained by the data is the physical position of the memory, which has specific characteristics defined by the data format. However, the principles of the present invention are described in the above text, which does not represent a limitation. Those skilled in the art will understand that the following various steps and operations can also be implemented in hardware.

[0019] The term "module" or "unit" used herein can be regarded as a software object executed on the computing system. Different components, modules, engines, and services herein can be regarded as implementation objects on the computing system. The devices and methods herein are preferably implemented in software, and of course, can also be implemented in hardware, all within the scope of protection of the present invention.

[0020] Those skilled in the art can understand that, unless specifically stated otherwise, the singular forms "a", "an", and "the" used herein may also include the plural forms. It should be further understood that the term "comprising" used in the specification of the present invention means the presence of features, integers, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or their groups. It should be understood that when we say an element is "connected" or "coupled" to another element, it can be directly connected or coupled to other elements, or there may also be intermediate elements. In addition, the "connection" or "coupling" used herein may include wireless connection or wireless coupling. The phrase "and / or" used herein includes all or any unit and all combinations of one or more associated listed items.

[0021] An embodiment of the present invention proposes a method for high-speed and strong real-time guarantee of the attitude measurement information of shipborne main inertial navigation equipment, which is mainly used to overcome the benchmark transfer error factors such as ship platform movement and transmission delay as much as possible during the design process of the navigation attitude reference information guarantee for large and medium-sized surface ships, and solve the problem of accurately transmitting the attitude measurement information of shipborne main inertial navigation equipment to attitude information users such as shipborne radars, so as to effectively guarantee the high-precision information guarantee requirements of various navigation attitude reference information users such as shipborne radars.

[0022] In view of the possible benchmark transfer errors caused by ship platform movement and transmission delay during the transmission process of navigation attitude reference information for large and medium-sized surface ships, an embodiment of the present invention proposes a method for strong real-time and high-speed attitude measurement information guarantee. Specifically, it includes content such as the time synchronization method of attitude measurement data packets, the high-speed attitude measurement information interpolation method, and the selection of information transmission methods, as Figure 1 shown, and includes the following steps: S101: Using the time code information of the ship-wide time reference as the absolute time, and using the synchronous second pulse of the time reference to complete the timestamp synchronization of the inertial navigation attitude information; S102: Determining the target frequency according to the interpolation requirements, and linearly interpolating the data packets sent by the inertial device into data of the target frequency; S103: After converting the data of the target frequency into optical signals, transmitting information through optical waves to achieve strong real-time transmission of high-speed attitude measurement information.

[0023] In the embodiment of the present invention, the time synchronization method of the attitude measurement data packet in step S101 specifically includes: using the time code information of the ship-wide time reference as the absolute time, and using the 1PPS second pulse of the time reference to complete the whole-second latching of the navigation information, so as to deduce the Beijing time generated in real time by the navigation information and realize the synchronization relationship between the data and the time reference.

[0024] As Figure 2As shown, a method for synchronizing the timestamp of inertial navigation attitude information based on the synchronous second pulse of a time reference device mainly includes the following steps: S1: Utilize the navigation information processing board in the master inertial navigation that contains a DSP and an FPGA; S2: Introduce the 200Hz attitude information and the PPS second pulse information of the time reference into the navigation information processing board containing the FPGA; S3: The FPGA, triggered by the rising edge of the second pulse according to the two signals, latches the nearest 200Hz data packet of the second pulse nearby, and transmits the latched data packet and the delay between the data packet and the second pulse to the serial port of the DSP for parsing; S4: The DSP synchronously parses the whole second data packet latched by the FPGA and the time code information of the time reference device; Let the Beijing time in the time code information be t1, the running time of the inertial navigation device in the data packet be t2 (the internal counter of the inertial navigation device, which accumulates with time), the delay between the data packet and the second pulse be Δt1, and then subtract the delay error Δt2 caused by the transmission from the data generation of the inertial device IMU to the calculation board. Thus, the time difference between the Beijing time and the running time of the inertial navigation is: Δt = t1 - t2 + Δt1 + Δt2 S5: When the DSP receives the 200Hz attitude information, if the running time of the inertial navigation in the data packet is parsed as t2′, the corresponding timestamp t1′ can be obtained as: t1′ = Δt + t2′ In the embodiment of the present invention, the high-speed attitude measurement information interpolation method in step S102 includes: As Figure 3 shown, the method steps for linearly interpolating 200Hz data into 1000Hz data are as follows: S1: Use the quartz crystal oscillator built in the FPGA to generate a 1000Hz interrupt; S2: Each time the 1000Hz interrupt is triggered, obtain a time difference between the interrupt and the nearest 200Hz data, denoted as Δt′.

[0025] Furthermore, it includes the following process: ① Interpolation requirement determination method The maximum roll amplitude allowed by the platform under sea conditions is R 0 , and the minimum roll period is Tr; the maximum pitch amplitude allowed by the platform under sea conditions is P 0 , and the minimum pitch period is T p ; the user requires the roll to be R′ and the pitch to be P′ for the time delay and the attitude reference transfer error link caused by platform movement; the update rate of the master inertial navigation attitude measurement information is G 0; The update rate of the main inertial navigation attitude measurement information required by the user is G 1 ; Then: R 0 / (Tr * G 1 ) ≤ R′ P 0 / (Tp * G 1 ) ≤ P′ ② Information interpolation design method Adopt the linear interpolation method to greatly improve the data output update rate to meet the requirement of high-speed output of attitude measurement information. Taking the conversion of the main inertial navigation attitude measurement information from 200Hz to 1000Hz high-frequency data as an example: Specifically, let the pitch P1, roll R1, heading H1, pitch angular rate PV1, roll angular rate RV1, and heading angular rate HV1 parsed from the 200Hz data packet, and Δt′ be the time difference between the interpolation moment and the integral 5ms data (the data interval when the main inertial navigation attitude measurement information is 200Hz).

[0026] The interpolated pitch P2, roll R2, and heading H2 are respectively: P2 = P1 + PV1 * Δt′ R2 = R1 + RV1 * Δt′ H2 = H1 + HV1 * Δt′ Then the high-speed attitude information updated at a frequency of 1000Hz can be obtained.

[0027] In the embodiment of the present invention, the selection of the real-time transmission method in step S103 includes: Select fiber optic communication. After converting the data of the target frequency into an optical signal through an optoelectronic conversion module, transmit information through optical waves to achieve strong real-time transmission of high-speed attitude measurement information.

[0028] As Figure 4 shown, the electrical signal forms a fiber optic communication channel through an optical transmitter, a fiber optic interface, a repeater, and an optical receiver module.

[0029] The strong real-time high-speed attitude information guarantee method provided by the embodiment of the present invention first establishes a data transmission model using the principle of fiber optic communication; then utilizes the advantages of FPGA and DSP in processing high-speed data to obtain timestamps through data latching and time deduction; and then uses the linear interpolation method to complete the conversion of 200Hz data to 1000Hz data.

[0030] The above has introduced in detail a method for ensuring strong real-time high-speed attitude measurement information provided by the embodiments of the present invention. Specific examples are used in this article to elaborate on the principle and implementation manner of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention; at the same time, for those skilled in the art, according to the idea of the present invention, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present invention.

Claims

1. A strong real-time high-speed attitude measurement information assurance method, characterized in that: include: The time code information of the whole ship time reference is used as the absolute time, and the synchronous second pulse of the time reference is used to complete the time stamp synchronization of the inertial navigation attitude information; Determine the target frequency according to the interpolation requirements, and linearly interpolate the data packets sent by the inertial device into data of the target frequency; After converting the data of the target frequency into an optical signal, the information is transmitted via light waves to achieve strong real-time transmission of high-speed attitude measurement information.

2. The method according to claim 1, characterized in that The method uses the time code information of the whole ship time reference as the absolute time and uses the synchronous second pulse of the time reference to complete the time stamp synchronization of the inertial navigation attitude information, including: Using the navigation information processing board including DSP and FPGA in the main inertial navigation, the data packet sent by the inertial device and the PPS pulse per second information of the time reference are introduced into the navigation information processing board, wherein the data packet includes the attitude information; The FPGA in the navigation information processing board uses the rising edge of the second pulse to trigger, latches the data packet closest to the second pulse, and transmits the latched data packet and the delay between the data packet and the second pulse to the serial port of the DSP for analysis; DSP synchronously analyzes the whole second data packet latched by FPGA and the time code information of the time reference device, and calculates the time difference between Beijing time and the inertial navigation operation time; When the DSP receives the data packet, if the inertial navigation operation time in the data packet is parsed, the corresponding timestamp is obtained from the time difference between Beijing time and the inertial navigation operation time.

3. The method according to claim 2, characterized in that The time difference Δt between Beijing time and inertial navigation operation time is calculated by Δt = t1-t2 +Δt1+Δt2, where t1 is the Beijing time in the time code information, t2 is the inertial navigation device operation time in the data packet, Δt1 is the delay between the data packet and the second pulse, and Δt2 is the delay error caused by the inertial device from data generation to transmission to the navigation information processing board.

4. The method according to claim 3, characterized in that The corresponding timestamp t1′ is obtained by t1′=Δt + t2′, where t2′ is the inertial navigation running time in the data packet.

5. The method according to any one of claims 1 to 4, characterized in that: Determining the target frequency according to the interpolation requirement and linearly interpolating the data packet sent by the inertial device into data of the target frequency includes: Determine the target frequency according to the interpolation requirements, and use the quartz crystal oscillator built into the FPGA to generate an interrupt of the target frequency; Each time an interrupt is triggered, the time difference with the most recent data packet is obtained and interpolated based on the time difference.

6. The method according to claim 5, characterized in that The step of determining the target frequency according to the interpolation requirement includes: The maximum roll amplitude under the allowable sea conditions is R0, and the minimum roll period is Tr. The maximum pitch amplitude under the allowable sea conditions is P0, and the minimum pitch period is T p ; The user requires that the roll be R′ and the pitch be P′ for the attitude reference transmission error link caused by time delay and platform motion, the main inertial navigation attitude measurement information frequency is G0, and the main inertial navigation attitude measurement information target frequency required by the user is G1; then: R0 / (Tr*G1)≤R′, P0 / (Tp*G1)≤P′.

7. The method according to claim 6, characterized in that The interpolated pitch P2, roll R2 and heading H2 are: P2 = P1 + PV1*Δt′, R2 = R1 + RV1*Δt′, H2 = H1 + HV1*Δt′, where Δt′ is the time difference between the most recent data packet and the data packet triggered each time the interrupt is triggered, P1 is the pitch parsed from the data packet sent by the inertial device, R1 is the roll parsed from the data packet sent by the inertial device, H1 is the heading parsed from the data packet sent by the inertial device, PV1 is the pitch angular rate parsed from the data packet sent by the inertial device, RV1 is the roll angular rate parsed from the data packet sent by the inertial device, and HV1 is the heading angular rate parsed from the data packet sent by the inertial device.

8. The method according to claim 7, characterized in that After converting the data of the target frequency into an optical signal, transmitting the information via the optical wave comprises: Optical fiber communication is selected to convert the data of the target frequency into an optical signal through a photoelectric conversion module, and then the information is transmitted through light waves to achieve strong real-time transmission of high-speed posture measurement information.

9. The method according to claim 8, characterized in that The photoelectric conversion module includes an optical transmitter, an optical fiber interface, a repeater and an optical receiver which are connected in sequence.

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