High-precision time service, time keeping and positioning integrated equipment based on Beidou third satellite system
Technical Field
The utility model relates to a satellite navigation technical field, especially a high accuracy time service, punctuality, location integration equipment based on No. three satellite system of big dipper.
Background
With the rapid development of the Beidou navigation industry, more and more products are available in the market for positioning, time service and time keeping. However, these products cannot be integrated, and have the problem of insufficient positioning precision or punctuality accuracy, and cannot be put into market application. The time and space integration is more studied for the power industry, the requirement of high-precision positioning is provided for equipment, and the requirement of high-precision time service and time keeping can be realized.
Disclosure of Invention
In view of this, the utility model aims at providing a high accuracy time service, when keeping watch on, location integration equipment based on No. three satellite system of big dipper collects on a equipment with GNSS location time service solution unit, GNSS unit of keeping watch on.
The utility model discloses a following scheme realizes: a transformer substation reactor operation temperature monitoring device comprises an MCU processing unit, a GNSS positioning time service resolving unit, a GNSS time service unit, a 4G communication unit, a multi-channel time service interface and a display unit, wherein the GNSS positioning time service resolving unit, the GNSS time service unit, the 4G communication unit, the multi-channel time service interface and the display unit are connected with the MCU processing unit; the GNSS active antenna is connected with the GNSS positioning time service resolving unit, and the 4G communication antenna is connected with the 4G communication unit;
the GNSS positioning time service resolving unit is also connected with the GNSS time keeping unit and is used for adopting a local clock acclimatized by the GNSS time keeping unit after the satellite signals are unlocked;
the GNSS positioning time service resolving unit is also connected with the 4G communication unit and is used for receiving RTX differential data sent by the 4G communication unit;
the GNSS positioning time service resolving unit is also connected with the GNSS active antenna and is used for receiving the BDS B1 signal and the GPS L1 signal amplified by the GNSS active antenna;
the multi-channel time service interface is connected with the power post-stage equipment and is used for actively time service.
Preferably, the working principle of the device in this embodiment is that the GNSS active antenna receives the BDS B1 signal and the GPS L1 signal, amplifies the signals, and transmits the amplified signals to the GNSS positioning time service resolving unit; the GNSS positioning time service resolving unit tracks and captures a BDS B1 signal and a GPS L1 signal, and resolves positioning information and time information; the 4G communication antenna receives RTK differential data and transmits the RTK differential data to the 4G communication unit for data intercommunication among the platforms; the GNSS time keeping unit is used for maintaining time information after the satellite signals are out of lock; the multichannel time service interface is connected with the electric power post-stage equipment to realize active time service. The GNSS positioning time service resolving unit and the GNSS time keeping unit can be realized by adopting the existing modules (including the built-in existing algorithm).
Furthermore, the multi-channel time service interface (including eight time service channels) comprises a radio frequency SMA interface for outputting 1PPS pulse and a serial interface for outputting timestamp messages. When satellite signals exist, the 1PPS pulse directly adopts the 1PPS signal output by the GNSS positioning time service resolving unit, and when satellite signals do not exist, the 1PPS pulse uses the taming 1PPS signal of the GNSS time service resolving unit; the rising edge of the 1PPS pulse indicates the time of the second, and the timestamp message indicates the year, month, day, hour, minute and second of the occurrence.
Further, the 4G communication unit includes two data channels, which are socket 1 and socket 2, respectively, where socket 1 is connected to the thousand-hunt FindCM server, and socket 2 is connected to the monitoring platform server.
Furthermore, the GNSS active antenna is connected with the GNSS positioning time service resolving unit through a wire-connection RF cable.
Preferably, the GNSS positioning time service resolving unit tracks signals BDS B1 and GPS L1, receives an original observation input, fixes a carrier period N value, and resolves a centimeter-level position solution and a 20 ns-level time solution. The original observation quantity is differential data in an RTCM3.2 format and comes from a thousand FindCM services, wherein socket 1 receives the differential data from the thousand FindCM services, and a mounting point is RTCM 32-GGB. The differential data is in RTCM3.2 format, and the differential text ID is: 1005(10),1074(1),1084(1),1124(1). socket 2 is specifically connected according to the monitoring server.
Preferably, after successful positioning, the GNSS timekeeping unit adopts a satellite second pulse signal 1PPS to implement high-precision taming of the local clock. The method specifically comprises the following steps: the GNSS time keeping unit extracts the CA code of the BDS B1 through radio frequency down-conversion, performs correlation value operation on the CA code and the CA code output by the local CA code generator to obtain a local clock error, sends the clock error to the voltage control end of the phase-locked loop after passing through an n-order low-pass filter, adjusts the output frequency of the phase-locked loop and feeds the frequency back to the local CA code generator to be used as a reference clock of the local CA code generator; and the satellite pulse-per-second signal 1PPS signal is controlled by a temperature compensated crystal oscillator TXCO after passing through a low-pass filter, so that the stability of the local carrier frequency is improved. The whole loop can be converged at last, namely, the phase-locked loop can output a stable and highly accurate clock, and the domestication and the maintenance of the local clock are realized.
Preferably, the display unit is used for displaying the positioning information, the time information and other information.
Preferably, the utility model discloses still include power management unit (can adopt current battery management module) for the power inserts the management. Including AC-DC conversion, backup power, over-current over-voltage protection, anti-reverse protection, ESD protection, etc.
The utility model discloses in, MCU processing unit obtains the differential data that comes from thousand seeking through socket 1 of 4G module, sends differential data to the resolving of GNSS location time service unit participation location time service. And on the one hand, the calculated positioning time service information is displayed through a display unit, and on the other hand, the positioning time service information is transmitted to a rear-stage terminal device needing time service, such as an electric power DTU/FTU and the like, through a multi-channel time service interface. The Beidou/GPS positioning time service unit can not track the satellite in real time due to external factors, so that the time keeping unit is added to discipline the local clock, and the time keeping effect is achieved. And finally, the MCU can be connected to a background server through a socket 2 of the 4G module, and reports necessary position information, time information and equipment state information to the background.
Compared with the prior art, the utility model discloses following beneficial effect has: the utility model discloses an equipment is with GNSS location time service solve unit, GNSS unit set of keeping watch on an equipment.
Drawings
Fig. 1 is a schematic block diagram of an embodiment of the present invention.
Fig. 2 is a schematic block diagram of a GNSS timekeeping unit according to an embodiment of the present invention.
Fig. 3 is a schematic diagram of a GNSS active antenna circuit according to an embodiment of the present invention.
Fig. 4 is a schematic circuit diagram of a GNSS positioning time service resolving unit according to an embodiment of the present invention.
Fig. 5 is a schematic circuit diagram of a GNSS time keeping unit according to an embodiment of the present invention.
Fig. 6 is a schematic circuit diagram of a 4G communication unit according to an embodiment of the present invention.
Fig. 7 is a diagram illustrating the positioning effect of the embodiment of the present invention. Wherein, (a) is a static positioning out-of-scene coincidence target map. (b) And fixing the local enlarged view after solution for the static positioning scene.
Fig. 8 is the serial port output time service information of the embodiment of the present invention.
Fig. 9 is a circuit diagram of a multi-channel time service interface according to an embodiment of the present invention.
Detailed Description
The present invention will be further explained with reference to the drawings and the embodiments.
As shown in fig. 1, the present embodiment provides a device for monitoring an operating temperature of a transformer substation reactor, which includes an MCU processing unit, and a GNSS positioning time service resolving unit, a GNSS time service unit, a 4G communication unit, a multi-channel time service interface, and a display unit connected thereto; the GNSS active antenna is connected with the GNSS positioning time service resolving unit, and the 4G communication antenna is connected with the 4G communication unit;
the GNSS positioning time service resolving unit is also connected with the GNSS time keeping unit and is used for adopting a local clock acclimatized by the GNSS time keeping unit after the satellite signals are unlocked;
the GNSS positioning time service resolving unit is also connected with the 4G communication unit and is used for receiving RTX differential data sent by the 4G communication unit;
the GNSS positioning time service resolving unit is also connected with the GNSS active antenna and is used for receiving the BDS B1 signal and the GPS L1 signal amplified by the GNSS active antenna;
the multi-channel time service interface is connected with the power post-stage equipment and is used for actively time service.
Preferably, the working principle of the device in this embodiment is that the GNSS active antenna receives the BDS B1 signal and the GPS L1 signal, amplifies the signals, and transmits the amplified signals to the GNSS positioning time service resolving unit; the GNSS positioning time service resolving unit tracks and captures a BDS B1 signal and a GPS L1 signal, and resolves positioning information and time information; the 4G communication antenna receives RTK differential data and transmits the RTK differential data to the 4G communication unit for data intercommunication among the platforms; the GNSS time keeping unit is used for maintaining time information after the satellite signals are out of lock; the multichannel time service interface is connected with the electric power post-stage equipment to realize active time service. The GNSS positioning time service resolving unit and the GNSS time keeping unit can be realized by adopting the existing modules (including the built-in existing algorithm).
In this embodiment, the multi-channel time service interface (including eight time service channels) includes a radio frequency SMA interface for outputting 1PPS pulses and a serial interface for outputting timestamp messages. When satellite signals exist, the 1PPS pulse directly adopts the 1PPS signal output by the GNSS positioning time service resolving unit, and when satellite signals do not exist, the 1PPS pulse uses the taming 1PPS signal of the GNSS time service resolving unit; the rising edge of the 1PPS pulse indicates the time of the second, and the timestamp message indicates the year, month, day, hour, minute and second of the occurrence. The circuit of the multi-channel time service interface is shown in fig. 9.
In this embodiment, the 4G communication unit includes two data channels, which are socket 1 and socket 2, respectively, where socket 1 is connected to the dns FindCM server, and socket 2 is connected to the monitoring platform server. The circuit diagram of the 4G communication unit is shown in FIG. 6, and the chips used in the 4G communication unit are a remote 4G communication module EC20, SN74LVC2T45-Q1, SSM63512NU, and ESDA6V1-5W 6.
In this embodiment, the GNSS active antenna is connected to the GNSS positioning time service resolving unit through a wire-line RF cable. The circuit diagram of the GNSS active antenna is shown in fig. 3. The chip adopted by the method comprises a low noise amplifier MGA-633, a gain amplifier ABA-32563, a filter SF9155 and a filter ACPF-7041.
Preferably, in this embodiment, the GNSS positioning time service resolving unit tracks signals of BDS B1 and GPS L1, receives an original observation input, fixes a carrier period N value, and resolves a centimeter-level position solution and a 20 ns-level time solution. The original observation quantity is differential data in an RTCM3.2 format and comes from a thousand FindCM services, wherein socket 1 receives the differential data from the thousand FindCM services, and a mounting point is RTCM 32-GGB. The differential data is in RTCM3.2 format, and the differential text ID is: 1005(10),1074(1),1084(1),1124(1). socket 2 is specifically connected according to the monitoring server.
A circuit diagram of the GNSS positioning time service resolving unit is shown in FIG. 4. The chip model used was ATGS 01.
Preferably, in this embodiment, after successful positioning, the GNSS time keeping unit uses the satellite pulse-per-second signal 1PPS to implement high-precision taming of the local clock. The method specifically comprises the following steps: the GNSS time keeping unit extracts the CA code of the BDS B1 through radio frequency down-conversion, performs correlation value operation on the CA code and the CA code output by the local CA code generator to obtain a local clock error, sends the clock error to the voltage control end of the phase-locked loop after passing through an n-order low-pass filter, adjusts the output frequency of the phase-locked loop and feeds the frequency back to the local CA code generator to be used as a reference clock of the local CA code generator; and the satellite pulse-per-second signal 1PPS signal is controlled by a temperature compensated crystal oscillator TXCO after passing through a low-pass filter, so that the stability of the local carrier frequency is improved. The whole loop can be converged at last, namely, the phase-locked loop can output a stable and highly accurate clock, and the domestication and the maintenance of the local clock are realized.
The schematic diagram of the GNSS time keeping unit is shown in fig. 2, the circuit diagram is shown in fig. 5, and the chips used by the GNSS time keeping unit include eight CDs 74HC4067SM96, MAX3232EUE, and AP 3407A.
Preferably, the display unit is used for displaying the positioning information, the time information and other information.
Preferably, the utility model discloses still include power management unit (can adopt current battery management module) for the power inserts the management. Including AC-DC conversion, backup power, over-current over-voltage protection, anti-reverse protection, ESD protection, etc.
The utility model discloses in, MCU processing unit obtains the differential data that comes from thousand seeking through socket 1 of 4G module, sends differential data to the resolving of GNSS location time service unit participation location time service. And on the one hand, the calculated positioning time service information is displayed through a display unit, and on the other hand, the positioning time service information is transmitted to a rear-stage terminal device needing time service, such as an electric power DTU/FTU and the like, through a multi-channel time service interface. The Beidou/GPS positioning time service unit can not track the satellite in real time due to external factors, so that the time keeping unit is added to discipline the local clock, and the time keeping effect is achieved. And finally, the MCU can be connected to a background server through a socket 2 of the 4G module, and reports necessary position information, time information and equipment state information to the background. Wherein, MCU can adopt the model STM32F103 RC's singlechip.
Preferably, as shown in fig. 7, the positioning effect diagram of the apparatus of this embodiment is shown in the external coincidence target diagram, and it can be seen from the external coincidence target diagram that the apparatus has a small number of floating solutions (RTK initialization) with a precision of about 2m, and immediately after obtaining the fixed solution, the floating solution is converted into a precision within 0.5m (99% CEP), and as can be seen from the partially enlarged view, the positioning error is less than 10cm after obtaining the fixed solution.
Fig. 8 shows that the serial port outputs the time service information according to the embodiment of the present invention, and as shown in fig. 8, the time information (which is determined which time and which day of which month and which day are several minutes and several seconds) can be output according to the NMEA-0183 protocol, and the rising edge of the t-second pulse in the time-keeping second pulse output by the serial port is combined, so that the time corresponding to the second can be accurately known, and the time service precision can reach 20 ns. In addition, through experiments, the difference Δ t =20.0095us/12h (about 0.834 us/h) between the measurement value of 1PPS one-tenth period after 24 hours of satellite loss of lock and the measurement value before satellite loss of lock is better than the time synchronization system part 1 of the electric power system of the electric power standard DLT 1100.1-2009: the time accuracy in the time keeping state is better than 0.92us/min (55 us/h) according to the time keeping performance requirement in the technical specification.
In particular, the specific circuits in the figures are only an example and may be replaced by other circuits with corresponding functions.
It is worth mentioning that the utility model protects a hardware structure, and does not require protection as to control method, working process, etc. The above is only a preferred embodiment of the present invention. However, the present invention is not limited to the above embodiments, and any equivalent changes and modifications made according to the present invention do not exceed the scope of the present invention, and all belong to the protection scope of the present invention.