CN212540723U - Wireless filling system for underwater Beidou navigation ephemeris and almanac - Google Patents
Wireless filling system for underwater Beidou navigation ephemeris and almanac Download PDFInfo
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- CN212540723U CN212540723U CN202020565103.3U CN202020565103U CN212540723U CN 212540723 U CN212540723 U CN 212540723U CN 202020565103 U CN202020565103 U CN 202020565103U CN 212540723 U CN212540723 U CN 212540723U
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Abstract
The utility model discloses an underwater Beidou navigation ephemeris and almanac wireless filling system, which relates to the technical field of Beidou navigation and comprises a receiving function module, a transmitting signal generating module, a special transmitting antenna module and a user satellite navigation positioning module, wherein the transmitting signal generating module comprises an intermediate frequency digital signal generating module, a DAC module, a low-pass filtering module, an OSC module, a PLL frequency point, a frequency converter, a frequency point filter, a combiner, an attenuator and an antenna; for the first quick location ability that improves big dipper satellite navigation orientation module, provide a wireless filling system of big dipper navigation ephemeris and almanac under water, carried out analysis and planning to each circuit unit's in the system emission module frequency and level, the utility model provides a low pass filter module comprises electric capacity and inductance, through microstrip line connection between the resistance of this low pass filter module and the inductance, guaranteed the microwave performance when circuit structure is simple low cost.
Description
Technical Field
The utility model relates to a big dipper navigation technology field especially relates to a big dipper navigation ephemeris and wireless filling system of almanac under water.
Background
The Beidou satellite navigation receiving equipment generally receives Beidou satellite signals to obtain navigation ephemeris and almanac, and then realizes positioning calculation. The navigation ephemeris is used for position location calculations and the almanac is used for the receiving device to quickly acquire satellites and to predict satellite positions. The validity of the navigation ephemeris is typically 4 hours and the validity of the almanac is typically half a year. Because the positioning buoy used by the underwater vehicle for position correction and the Beidou satellite navigation and positioning module in the weapon system are in a storage state for a long time, after the underwater vehicle is put into use, navigation ephemeris and almanac are generally updated so as to be capable of positioning and outputting. It often takes several minutes from power-up to outputting the positioning result. During combat, if the satellite navigation civil signals are interfered by enemies, the Beidou satellite navigation positioning module can only complete positioning by capturing and tracking the military signals. Thus, the time required to complete the first positioning may be longer. For precision guided weapons and correction of underwater vehicle position, extended first fix times will affect weapons effectiveness and increase exposure of the underwater vehicle. Therefore, it is necessary to manually initialize the Beidou satellite navigation and positioning module before the positioning buoy and the weapon are used, so as to shorten the positioning time, fully exert the weapon efficiency and reduce the exposure risk of the underwater vehicle.
SUMMERY OF THE UTILITY MODEL
The utility model aims to solve the technical problem that for the first quick location ability that improves big dipper satellite navigation orientation module in to the background art, provide a big dipper navigation ephemeris and the wireless filling system of almanac under water, carried out analysis and planning to each circuit unit's in the system emission module frequency and level, the adoption realizes based on FPGA + ARM's framework, through manual work in advance filling almanac and ephemeris, can effectively shorten big dipper satellite navigation orientation module's first fix time.
The utility model discloses a solve above-mentioned technical problem and adopt following technical scheme:
an underwater Beidou navigation ephemeris and almanac wireless filling system comprises a receiving function module, a transmitting signal generating module, a special transmitting antenna module and a user satellite navigation positioning module; the transmitting signal generating module comprises an intermediate frequency digital signal generating module, a first DAC module, a first low-pass filtering module, a second DAC module, a second low-pass filtering module, an OSC module, a first PLL B1 frequency point, a second PLL B2 frequency point, a first frequency converter, a second frequency converter, a B1 frequency point filter, a B2 frequency point filter, a combiner, an attenuator and an antenna; the device comprises an intermediate-frequency digital signal generation module, a first DAC module, a first low-pass filtering module, a first frequency converter, a B1 frequency point filter, a combiner, an attenuator and an antenna which are sequentially connected, wherein the intermediate-frequency digital signal generation module sequentially passes through a second DAC module, a second low-pass filtering module, a second frequency converter and a B2 frequency point filter to be connected with the combiner, the intermediate-frequency digital signal generation module sequentially passes through an OSC module and a PLL B1 frequency point to be connected with the first frequency converter, and the OSC module is connected with the second frequency converter through a PLL B2 frequency point; the intermediate-frequency digital signal generation module comprises an FPGA module, an ARM module, a user display control interface, a data SRAM module, a data conversion module, an RS422 interface module, a D/A module, a RTC module, a PXX module and a power supply module, wherein the FPGA module is connected with the user display control interface through the ARM module, the ARM module is connected with the RS422 interface module through the data conversion module, and the data SRAM module, the D/A module, the RTC module, the PXX module and the power supply module are respectively connected with the FPGA module; the first low-pass filtering module and the second low-pass filtering module respectively comprise an input port, an output port, a first filtering unit and a second filtering unit, the input port is connected with the input end of the first filtering unit, the output end of the first filtering unit is connected with the input end of the second filtering unit, and the output end of the second filtering unit is connected with the output port; the first filtering unit comprises a first inductor and a first capacitor, one end of the first inductor is connected with the input end of the first filtering unit, the other end of the first inductor is connected with the output end of the first filtering unit, one end of the first capacitor is connected with the other end of the first inductor, and the other end of the first capacitor is connected with the grounding end; the second filtering unit comprises a second inductor and a second capacitor, one end of the second inductor is connected with the input end of the second filtering unit, the other end of the second inductor is connected with the output end of the second filtering unit, one end of the second capacitor is connected with the other end of the second inductor, and the other end of the second capacitor is connected with the grounding end; the input port, the output port, the first inductor, the first capacitor, the second inductor and the second capacitor are connected through microstrip lines.
As the utility model relates to a big dipper navigation ephemeris and the wireless filling system's of almanac further preferred scheme under water, the inductance value of first inductance and second inductance is 18nH, and the capacitance value of first electric capacity and second electric capacity is 4.7 pF.
As the utility model relates to a big dipper navigation ephemeris and the wireless filling system's of almanac further preferred scheme under water, receive functional module and connect the transmission signal generation module through 1PPS interface or time service interface connection.
As the utility model relates to a further preferred scheme of wireless filling system of big dipper navigation ephemeris and almanac under water, the frequency of DAC module is 100MHz, adopts the AD9857 chip.
As the utility model relates to a further preferred scheme of filling system is wireless to big dipper navigation ephemeris and almanac under water, receive function module and adopt big dipper navigation user machine in the carrier.
The utility model adopts the above technical scheme to compare with prior art, have following technological effect:
1. the utility model provides an underwater Beidou navigation ephemeris and almanac wireless filling system for improving the first quick positioning capability of a Beidou satellite navigation positioning module, which analyzes and plans the frequency and level of each circuit unit in a system transmitting module, adopts the framework based on FPGA + ARM to realize, and can effectively shorten the first positioning time of the Beidou satellite navigation positioning module by manually filling the almanac and the ephemeris in advance;
2. the utility model provides a low-pass filtering module composed of a capacitor and an inductor, wherein the resistor and the inductor of the low-pass filtering module are connected through a microstrip line, the circuit structure is simple, the cost is low, and the microwave performance is ensured;
3. the utility model discloses receiving function module uses big dipper navigation user machine in the carrier, receives the navigation signal, analyzes out ephemeris and almanac, and transmits for the transmit function module in real time, transmit function module receives ephemeris and almanac data, and stores to local, when receiving function module carries out navigation information and receives, can carry out the timing to transmit function module through 1PPS interface and time service interface, transmit function module through the timing can realize the formation of satellite navigation signal;
4. the utility model discloses a solve underwater vehicle location buoy, the long problem of first location time after big dipper satellite navigation positioning module long-time storage in the weapon system, on the basis of different technical approach advantages and disadvantages has been analyzed, through wireless link to big dipper satellite navigation positioning module manual filling almanac and ephemeris in advance, the scheme that the signal processing link function integrity that can also navigate simultaneously detected, the hardware that has given emission module realizes and overall frequency and level planning, the system is through wireless manual filling almanac and ephemeris in advance, shorten first location time, to full play weapon efficiency and improvement underwater vehicle survival ability, important military application value has.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.
FIG. 1 is a schematic structural diagram of the underwater Beidou navigation ephemeris and almanac wireless filling system of the present invention;
fig. 2 is a schematic structural diagram of the transmission signal generating module of the present invention;
fig. 3 is a schematic structural diagram of the intermediate frequency digital signal generating module of the present invention;
fig. 4 is a circuit diagram of the low-pass filtering module of the present invention.
The numbers in the figures are specified below: 1-an input port; 2-an output port; 3-a first filtering unit; 4-a second filtering unit; l1 — first inductance; l2 — second inductance; c1 — first capacitance; c2 — second capacitance; GND1 — first ground; GND 2-second ground.
Detailed Description
The technical scheme of the utility model is further explained in detail with the attached drawings as follows:
the technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.
The following technical approaches are mainly used for the manual initialization of the navigation and positioning module.
(1) The direct formula. The water surface, land-based and space-based carriers can have better satellite navigation signal receiving conditions, so that real navigation signals can be received at any time, or the satellite navigation signals received by the carriers are forwarded in real time in a forwarding mode, and the navigation ephemeris and the almanac are kept updated. However, for underwater vehicles, satellite navigation signals cannot be received during underwater navigation, and therefore, a direct technical approach cannot be adopted.
(2) And (4) injecting the position. The carrier position obtained from an inertial navigation system and the like is input into the module through a communication port of the Beidou satellite navigation and positioning module, and the Beidou satellite navigation and positioning module calculates an almanac according to the carrier position, so that rapid satellite signal acquisition is realized. The method needs external auxiliary signals such as an inertial navigation system and the like, and also needs the Beidou satellite navigation and positioning module to support almanac calculation, and most of the Beidou satellite navigation and positioning modules currently used do not support almanac calculation, so that the Beidou satellite navigation and positioning module needs to be upgraded, and the workload is large and unrealistic.
(3) Wireless injection. And a satellite navigation signal is generated through simulation, an ephemeris or an almanac which needs to be added is modulated, and then the ephemeris or the almanac is transmitted to the Beidou satellite navigation and positioning module through a wireless link. The Beidou satellite navigation and positioning module analyzes the ephemeris or the almanac after receiving the analog signal through the antenna, thereby completing injection. The filling of the initialization parameters through the wireless link is an injection mode with the minimum influence on the existing Beidou satellite navigation and positioning module, the existing Beidou satellite navigation and positioning module does not need to be modified, and meanwhile, the Beidou satellite navigation and positioning module can be subjected to full-function detection from an antenna before use.
In conclusion, the initialization of the Beidou satellite navigation and positioning module is realized by adopting a wireless injection type technical approach.
An underwater Beidou navigation ephemeris and almanac wireless filling system is shown in figure 1 and comprises a receiving function module, a transmitting signal generating module, a special transmitting antenna module and a user satellite navigation positioning module, wherein the receiving function module is connected with the user satellite navigation positioning module through the transmitting signal generating module and the special transmitting antenna module in sequence;
the receiving function module receives navigation signals of B1 and B3 frequency points by using a Beidou navigation user machine in a carrier, analyzes ephemeris and almanac and transmits the ephemeris and almanac to the transmitting function module in real time. And the transmitting functional module receives the ephemeris and the almanac data and stores the ephemeris and the almanac data to the local. When the receiving function module receives the navigation information, the transmitting function module can be calibrated through the 1PPS interface and the time service interface. The satellite navigation signal can be generated through the time-correcting transmitting functional module; before the Beidou satellite navigation and positioning module needs to realize positioning or when a navigation function test is carried out, the injection module calls the transmission function module, stored ephemeris and almanac are modulated to a navigation signal, and the navigation signal is transmitted through an antenna. The Beidou satellite navigation positioning module receives the transmitted navigation signals from the antenna, carries out a series of processing such as acquisition, tracking, bit synchronization, frame synchronization and the like, analyzes ephemeris and almanac, obtains data which can be used for initialization, and simultaneously tests the functional integrity of the whole navigation link.
As shown in fig. 2, the transmission signal generating module includes an intermediate frequency digital signal generating module, a first DAC module, a first low pass filter module, a second DAC module, a second low pass filter module, an OSC module, a first PLL B1 frequency point, a second PLL B2 frequency point, a first frequency converter, a second frequency converter, a B1 frequency point filter, a B2 frequency point filter, a combiner, an attenuator, and an antenna; the device comprises an intermediate-frequency digital signal generation module, a first DAC module, a first low-pass filtering module, a first frequency converter, a B1 frequency point filter, a combiner, an attenuator and an antenna which are sequentially connected, wherein the intermediate-frequency digital signal generation module sequentially passes through a second DAC module, a second low-pass filtering module, a second frequency converter and a B2 frequency point filter to be connected with the combiner, the intermediate-frequency digital signal generation module sequentially passes through an OSC module and a PLL B1 frequency point to be connected with the first frequency converter, and the OSC module is connected with the second frequency converter through a PLL B2 frequency point; the intermediate frequency digital signal generation module comprises an FPGA module, an ARM module, a user display control interface, a data SRAM module, a data conversion module, an RS422 interface module, a DA module, a RTC module, a PXX module and a power supply module, the FPGA module is connected with the user display control interface through the ARM module, the ARM module is connected with the RS422 interface module through the data conversion module, and the data SRAM module, the DA module, the RTC module, the PXX module and the power supply module are respectively connected with the FPGA module.
The transmitting function module can work at the same time at the double frequency points of B1 and B3, and the baseband digital signal generating module generates the intermediate frequency signals of the frequency points of B1 and B3 at the same time and respectively outputs the intermediate frequency signals to different DACs and analog links; after a series of processing such as up-conversion, filtering and the like, the combined output of the B1 frequency points and the B3 frequency points is realized. The scheme has the advantages that signals of B1 and B3 frequency points can be output simultaneously, a PLL loop does not need to be configured, and fixed frequency can be set directly.
As shown in fig. 3, the intermediate frequency digital signal generation module includes an FPGA module, an ARM module, a user display control interface, a data SRAM module, a data conversion module, an RS422 interface module, a da module, an RTC module, a PXX module, and a power supply module, the FPGA module is connected to the user display control interface through the ARM module, the ARM module is connected to the RS422 interface module through the data conversion module, and the data SRAM module, the da module, the RTC module, the PXX module, and the power supply module are respectively connected to the FPGA module. The intermediate frequency digital signal generation module is realized based on a scheme of FPGA and ARM and comprises 1 FPGA chip and 1 ARM chip. The FPGA chip generates intermediate-frequency digital signals, and the ARM chip realizes the functions of intermediate-frequency signal generation control, text acquisition, display control and the like.
The baseband signal generating channel generates a baseband signal by utilizing a carrier wave, a pseudo code and the message data bit information to be injected. After the signal generation of each channel is completed, channel combination is required to be performed on each channel, and the I/Q branches are respectively combined and then output to the up-conversion module. The B1 and B3 frequency signals are generated as baseband signals separately, and the two frequency signals are not combined in the digital part.
As shown in fig. 4, each of the first low-pass filtering module and the second low-pass filtering module includes an input port 1, an output port 2, a first filtering unit 3, and a second filtering unit 4, where the input port 1 is connected to an input end of the first filtering unit 3, an output end of the first filtering unit 3 is connected to an input end of the second filtering unit 4, and an output end of the second filtering unit 4 is connected to the output port 2.
Further, the first filtering unit 3 includes a first inductor L1 and a first capacitor C1, one end of the first inductor L1 is connected to the input end of the first filtering unit 3, the other end of the first inductor L1 is connected to the output end of the first filtering unit 3, one end of the first capacitor C1 is connected to the other end of the first inductor L1, and the other end of the first capacitor C1 is connected to a first ground GND 1;
the second filtering unit 4 comprises a second inductor L2 and a second capacitor C2, one end of the second inductor L2 is connected to the input end of the second filtering unit 4, the other end of the second inductor L2 is connected to the output end of the second filtering unit 4, one end of the second capacitor C2 is connected to the other end of the second inductor L2, and the other end of the second capacitor C2 is connected to a second ground GND 2.
Furthermore, the input port 1, the output port 2, the first inductor L1, the first capacitor C1, the second inductor L2, and the second capacitor C2 are connected by microstrip lines, and the microstrip lines can be used for transmitting radio frequency microwave signals more stably.
From the above description, the beneficial effects of the present invention are: the low-pass filter is composed of a capacitor and an inductor, a resistor of the low-pass filter module is connected with the inductor through a microstrip line, the circuit structure is simple, the cost is low, and the microwave performance is guaranteed.
The inductance value of the first inductor and the second inductor is 18nH, and the capacitance value of the first capacitor and the second capacitor is 4.7 pF.
The frequency of the DAC module is 100MHz, the DAC module can be realized by adopting a common DAC chip, and an AD9857 chip is recommended.
And a common LC circuit is adopted to realize low-pass filtering of the intermediate frequency signal. Theoretically, the filter needs to be implemented by a band-pass filter, but because the intermediate frequency is low and the filtering is performed in the radio frequency part, a low-pass filtering module is used for simple implementation. The mixer function may be implemented using a mixer chip.
The antenna is realized by adopting a linear polarization antenna capable of transmitting B1 and B3 signals, and the antenna product is very mature. The satellite navigation equipment generally adopts a right-hand circularly polarized antenna to receive signals, and the linear polarized antenna is adopted to transmit navigation signals, so that the loss of 3dB signals at a receiving end can be caused, but when the system is applied, the distance between the receiving equipment and an injection module for signal transmission is very close, the attenuation of the signals in a space link is small, and therefore, even if the power loss of the signals is 3dB, the level planning requirement can be completely met.
Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present invention.
Claims (5)
1. The utility model provides a wireless filling system of big dipper navigation ephemeris and almanac under water which characterized in that: the system comprises a receiving function module, a transmitting signal generating module, a special transmitting antenna module and a user satellite navigation positioning module; the transmitting signal generating module comprises an intermediate frequency digital signal generating module, a first DAC module, a first low-pass filtering module, a second DAC module, a second low-pass filtering module, an OSC module, a first PLL B1 frequency point, a second PLL B2 frequency point, a first frequency converter, a second frequency converter, a B1 frequency point filter, a B2 frequency point filter, a combiner, an attenuator and an antenna; the device comprises an intermediate-frequency digital signal generation module, a first DAC module, a first low-pass filtering module, a first frequency converter, a B1 frequency point filter, a combiner, an attenuator and an antenna which are sequentially connected, wherein the intermediate-frequency digital signal generation module sequentially passes through a second DAC module, a second low-pass filtering module, a second frequency converter and a B2 frequency point filter to be connected with the combiner, the intermediate-frequency digital signal generation module sequentially passes through an OSC module and a PLL B1 frequency point to be connected with the first frequency converter, and the OSC module is connected with the second frequency converter through a PLL B2 frequency point;
the intermediate-frequency digital signal generation module comprises an FPGA module, an ARM module, a user display control interface, a data SRAM module, a data conversion module, an RS422 interface module, a D/A module, a RTC module, a PXX module and a power supply module, wherein the FPGA module is connected with the user display control interface through the ARM module, the ARM module is connected with the RS422 interface module through the data conversion module, and the data SRAM module, the D/A module, the RTC module, the PXX module and the power supply module are respectively connected with the FPGA module;
the first low-pass filtering module and the second low-pass filtering module respectively comprise an input port, an output port, a first filtering unit and a second filtering unit, the input port is connected with the input end of the first filtering unit, the output end of the first filtering unit is connected with the input end of the second filtering unit, and the output end of the second filtering unit is connected with the output port; the first filtering unit comprises a first inductor and a first capacitor, one end of the first inductor is connected with the input end of the first filtering unit, the other end of the first inductor is connected with the output end of the first filtering unit, one end of the first capacitor is connected with the other end of the first inductor, and the other end of the first capacitor is connected with the grounding end; the second filtering unit comprises a second inductor and a second capacitor, one end of the second inductor is connected with the input end of the second filtering unit, the other end of the second inductor is connected with the output end of the second filtering unit, one end of the second capacitor is connected with the other end of the second inductor, and the other end of the second capacitor is connected with the grounding end; the input port, the output port, the first inductor, the first capacitor, the second inductor and the second capacitor are connected through microstrip lines.
2. The underwater Beidou navigation ephemeris and almanac wireless filling system of claim 1, which is characterized in that: the inductance value of the first inductor and the second inductor is 18nH, and the capacitance value of the first capacitor and the second capacitor is 4.7 pF.
3. The underwater Beidou navigation ephemeris and almanac wireless filling system of claim 1, which is characterized in that: the receiving function module is connected with the transmitting signal generating module through a 1PPS interface or a time service interface.
4. The underwater Beidou navigation ephemeris and almanac wireless filling system of claim 1, which is characterized in that: the frequency of the DAC module is 100MHz, and an AD9857 chip is adopted.
5. The underwater Beidou navigation ephemeris and almanac wireless filling system of claim 1, which is characterized in that: and the receiving functional module adopts a Beidou navigation user machine in a carrier.
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117518210A (en) * | 2023-07-10 | 2024-02-06 | 北京路凯智行科技有限公司 | Terminal for mine satellite navigation and positioning |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN117518210A (en) * | 2023-07-10 | 2024-02-06 | 北京路凯智行科技有限公司 | Terminal for mine satellite navigation and positioning |
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