CN113377054A - Data synchronization method and device - Google Patents
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Abstract
The embodiment of the application provides a data synchronization method and a data synchronization device, and the method comprises the following steps: when a frequency multiplication clock signal arrives, triggering a first statistic operation and an acquisition operation, wherein the first statistic operation is used for counting the vibration times of a first clock crystal oscillator in an analog signal acquisition card; the acquisition operation is used for acquiring full-tensor magnetic data based on the sampling frequency of the analog signal acquisition card; triggering a second statistical operation when the falling edge of the first clock crystal oscillator arrives, wherein the second statistical operation is used for counting the vibration times of a second clock crystal oscillator in the FPGA case; when the next frequency doubling clock signal arrives, stopping the first statistic operation and acquiring the first vibration times of the first clock crystal oscillator, stopping the second statistic operation and acquiring the second vibration times of the second clock crystal oscillator; and determining the resampling position of the full-tensor magnetic data by utilizing the first vibration times, the second vibration times, the frequency multiplication clock signal and the sampling frequency so as to realize data synchronization between the full-tensor magnetic data and the pose data of the SPAN-CPT based on the resampling position.
Description
Technical Field
The present application relates to the field of superconducting applications, and in particular, to a data synchronization method and apparatus.
Background
The core sensor of the aeromagnetic superconducting full tensor gradient measurement and control system is a superconducting quantum interferometer, and a superconducting magnetic sensor formed by the superconducting quantum interferometer is a magnetic sensor with the highest sensitivity at present and can measure tiny magnetic signals. However, since the airborne platform is moving, magnetic compensation needs to be performed through high-precision attitude projection to eliminate the interference introduced by the motion of the airborne platform, and the interference is eliminated, so that not only the measurement precision of the position, attitude data and full tensor magnetic data is required to be as high as possible, but also the position, attitude data and full tensor magnetic data need to keep high synchronism, but in the airborne superconducting full tensor gradient measurement and control system, the full tensor magnetic data and the position and attitude data are not synchronous due to different data sources of the full tensor magnetic data and the position and attitude data, and the synchronization precision when data synchronization is performed through the prior art is low.
Disclosure of Invention
The embodiment of the application provides a data synchronization method and device, which can improve the synchronization precision during data synchronization.
The technical scheme of the application is realized as follows:
in a first aspect, an embodiment of the present application provides a data synchronization method, which is applied to a data synchronization device, where the data synchronization device is connected to an inertial navigation system SPAN-CPT, the data synchronization device includes a field programmable gate array FPGA chassis, and an analog signal acquisition card is inserted into a first card slot of the FPGA chassis, and the method includes:
when a frequency doubling clock signal arrives, triggering a first statistic operation and an acquisition operation, wherein the first statistic operation is used for counting the vibration times of a first clock crystal oscillator in the analog signal acquisition card; the acquisition operation is used for acquiring full-tensor magnetic data based on the sampling frequency of the analog signal acquisition card;
triggering a second statistical operation when the falling edge of the first clock crystal oscillator arrives, wherein the second statistical operation is used for counting the vibration times of a second clock crystal oscillator in the FPGA case;
when the next frequency doubling clock signal arrives, stopping the first statistic operation and acquiring the first vibration times of the first clock crystal oscillator, stopping the second statistic operation and acquiring the second vibration times of the second clock crystal oscillator;
and determining a resampling position of the full-tensor magnetic data by using the first vibration times, the second vibration times, the frequency multiplication clock signal and the sampling frequency so as to realize data synchronization between the full-tensor magnetic data and the pose data of the SPAN-CPT based on the resampling position.
In the above data synchronization method, the data synchronization apparatus further includes a digital input/output I/O acquisition card, and before triggering the first statistic operation and the acquisition operation when a frequency-doubled clock signal arrives, the method further includes:
and acquiring the PPS signal of the SPAN-CPT by using the digital I/O acquisition card, and performing frequency multiplication on the PPS signal to obtain a frequency multiplication clock signal.
In the above data synchronization method, after determining the resampling position of the full tensor magnetic data by using the first vibration number, the second vibration number, the frequency-multiplied clock signal and the sampling frequency, the method further includes:
under the condition that the resampling positions are integers, searching the resampling full tensor magnetic data corresponding to the resampling positions from the full tensor magnetic data;
under the condition that the resampling positions are not integers, taking the resampling positions as a center, and acquiring a plurality of integer resampling positions; searching a plurality of re-sampling full tensor magnetic data corresponding to the integer re-sampling positions from the full tensor magnetic data;
and obtaining the resampled full tensor magnetic data by using the plurality of resampled full tensor magnetic data.
In the above data synchronization method, the obtaining the resampled full tensor magnetic data by using the plurality of resampled full tensor magnetic data includes:
determining a plurality of weights corresponding to the plurality of integer resampling positions according to the position relation between the plurality of integer resampling positions and the resampling position;
and carrying out weighted average operation on the multiple pieces of resampled full-tensor magnetic data according to the multiple weights to obtain the resampled full-tensor magnetic data.
In the above data synchronization method, the data synchronization apparatus further includes a serial port acquisition card, and the sampling frequency of the frequency-doubled clock signal is an integer multiple of the sampling frequency of the serial port acquisition card, and the method further includes:
and acquiring the pose data of the SPAN-CPT by using the serial port acquisition card.
In a second aspect, an embodiment of the present application provides a data synchronization apparatus, where the data synchronization apparatus is connected to an inertial navigation system SPAN-CPT, and the apparatus includes:
the system comprises a compact reconfigurable input/output (cRIO) controller, a signal processing module and a signal processing module, wherein the cRIO controller comprises a programmable gate array (FPGA) case, and an analog signal acquisition card is inserted into a first card slot of the FPGA case; the analog signal acquisition card comprises a first clock crystal oscillator, and the FPGA case comprises a second clock crystal oscillator;
wherein,
the analog signal acquisition card is configured to trigger a first statistic operation and an acquisition operation when a frequency multiplication clock signal arrives, wherein the first statistic operation is used for counting the vibration times of the first clock crystal oscillator; the acquisition operation is used for acquiring full-tensor magnetic data based on the sampling frequency of the analog signal acquisition card, and when the next frequency doubling clock signal arrives, the first statistic operation is stopped, the first vibration frequency of the first clock crystal oscillator is acquired, and the first vibration frequency is transmitted to the cRIO controller;
the FPGA case is configured to trigger a second statistical operation when a falling edge of the first clock crystal oscillator arrives, wherein the second statistical operation is used for counting the vibration times of the second clock crystal oscillator, and when a next frequency doubling clock signal arrives, the second statistical operation is terminated, and the second vibration times of the second clock crystal oscillator are obtained and transmitted to the cRIO controller;
the cRIO controller is configured to determine a resampling position of the full-tensor magnetic data by using the first vibration times, the second vibration times, the frequency multiplication clock signal and the sampling frequency of the analog signal acquisition card, so as to realize data synchronization between the full-tensor magnetic data and the pose data of the SPAN-CPT based on the resampling position.
In the above data synchronization apparatus, the apparatus includes: a digital input/output I/O acquisition card is inserted into a second clamping groove of the FPGA case;
the digital I/O acquisition card is configured to acquire a PPS signal of the SPAN-CPT, and frequency-doubled the PPS signal to obtain a frequency-doubled clock signal.
In the above data synchronization apparatus, the apparatus includes: a serial port acquisition card is inserted into a third card slot of the FPGA case; the sampling frequency of the frequency multiplication clock signal is an integral multiple of the sampling frequency of the serial port acquisition card;
the serial port acquisition card is configured to acquire the pose data of the SPAN-CPT.
In the above data synchronization apparatus, the analog signal acquisition card is further configured to acquire the full tensor magnetic data by using the first 9 channels of the analog signal acquisition card.
In the data synchronization device, the analog signal acquisition card is NI 9202.
In the data synchronization device, the digital I/O acquisition card is NI 9467.
In the data synchronization device, the serial port acquisition card is NI 9870.
The embodiment of the application provides a data synchronization method and a data synchronization device, wherein the method comprises the following steps: when a frequency multiplication clock signal arrives, triggering a first statistic operation and an acquisition operation, wherein the first statistic operation is used for counting the vibration times of a first clock crystal oscillator in an analog signal acquisition card; the acquisition operation is used for acquiring full-tensor magnetic data based on the sampling frequency of the analog signal acquisition card; triggering a second statistical operation when the falling edge of the first clock crystal oscillator arrives, wherein the second statistical operation is used for counting the vibration times of a second clock crystal oscillator in the FPGA case; when the next frequency doubling clock signal arrives, stopping the first statistic operation and acquiring the first vibration times of the first clock crystal oscillator, stopping the second statistic operation and acquiring the second vibration times of the second clock crystal oscillator; determining a resampling position of the full-tensor magnetic data by utilizing the first vibration times, the second vibration times, the frequency multiplication clock signal and the sampling frequency so as to realize data synchronization between the full-tensor magnetic data and the pose data of the SPAN-CPT based on the resampling position; by adopting the implementation scheme, the data synchronization device counts the vibration times of the clock crystal oscillator of the analog signal acquisition card and the clock crystal oscillator of the FPGA case when a frequency doubling clock signal arrives, the resampling position of the full-tensor magnetic data under the frequency doubling clock signal can be calculated through the vibration times of the two clock crystal oscillators, and the resampling position of the full-tensor magnetic data is recalculated once when each frequency doubling clock signal arrives, so that the resampling position of the full-tensor magnetic data can be ensured not to be influenced by the error of the clock crystal oscillator on the FPGA case, and the precision of data synchronization is further improved.
Drawings
Fig. 1 is a flowchart of a data synchronization method according to an embodiment of the present application;
fig. 2 is a schematic diagram of frequency multiplication of an exemplary pulse per second PPS signal according to an embodiment of the present application;
fig. 3 is a schematic connection diagram of a data synchronization apparatus according to an embodiment of the present disclosure.
Detailed Description
It should be understood that the specific embodiments described herein are merely illustrative of the present application. And are not intended to limit the present application.
The aviation superconducting full tensor magnetic gradient data acquisition and control system not only needs to acquire full tensor magnetic data, but also needs position and attitude data corresponding to the full tensor magnetic data in real time, and the higher the synchronism is, the better the synchronism is. The attitude data is used for effectively eliminating interference introduced by the full-tensor magnetic data in the motion state, and then the spatial distribution information of the measured area can be obtained only by corresponding the full-tensor magnetic data after the interference is eliminated with the position information. Therefore, the measurement accuracy of the position and attitude data and the synchronism with the full-tensor magnetic data determine the data quality of the aviation superconducting full-tensor magnetic gradient data acquisition and control system.
The embodiment of the application provides a data synchronization method, which is applied to a data synchronization device, wherein the data synchronization device is connected with an inertial navigation system SPAN-CPT, the data synchronization device comprises a field programmable gate array FPGA (field programmable gate array) case, an analog signal acquisition card is inserted into a first card slot of the FPGA case, fig. 1 is a flow chart of the data synchronization method provided by the embodiment of the application, and as shown in fig. 1, the data synchronization method comprises the following steps:
s101, when a frequency multiplication clock signal arrives, triggering a first statistic operation and an acquisition operation, wherein the first statistic operation is used for counting the vibration times of a first clock crystal oscillator in an analog signal acquisition card; the acquisition operation is used to acquire full tensor magnetic data based on the sampling frequency of the analog signal acquisition card.
In this embodiment, the data synchronization device is connected to the inertial navigation system SPAN-CPT, and the data synchronization device includes: the compact reconfigurable input/output cRIO controller comprises a programmable gate array FPGA case and an analog signal acquisition card inserted into a first card slot of the FPGA case; the analog signal acquisition card comprises a first clock crystal oscillator, and the FPGA case comprises a second clock crystal oscillator.
The data synchronization device provided by the embodiment of the application is suitable for a scene of carrying out data synchronization on full-tensor magnetic data, position data and attitude data in an aeromagnetic superconducting full-tensor gradient measurement and control system.
In the embodiment of the application, because the data synchronization device comprises the analog signal acquisition card, when a frequency doubling clock signal arrives, the analog signal acquisition card triggers a first statistic operation and an acquisition operation, and the first statistic operation is used for counting the vibration times of a first clock crystal oscillator; the acquisition operation is used to acquire full tensor magnetic data based on the sampling frequency of the analog signal acquisition card.
It should be noted that the oscillation frequency of the first clock oscillator in the analog signal acquisition card is 12.8.
It should be noted that, before the analog signal acquisition card acquires the full tensor magnetic data by using the sampling frequency of the analog signal acquisition card, since the full tensor magnetic signal is very weak when being input into the analog signal acquisition card, the full tensor magnetic signal input into the analog signal acquisition card needs to be amplified and then acquired by using the amplifying circuit.
It should be noted that the sampling frequency of the analog signal acquisition card may be 6.25KHz, and the specific sampling frequency of the analog signal acquisition card may be determined according to an actual situation, which is not limited herein.
And S102, when the falling edge of the first clock crystal oscillator arrives, triggering second statistical operation, wherein the second statistical operation is used for counting the vibration times of the second clock crystal oscillator in the FPGA case.
In the embodiment of the application, since the data synchronization device includes the FPGA chassis, when the falling edge of the first clock crystal oscillator reaches, the FPGA chassis triggers the second statistical operation, and the second statistical operation is used for counting the vibration frequency of the second clock crystal oscillator in the FPGA chassis.
In an embodiment of the present application, the data synchronization apparatus further includes a digital input/output I/O acquisition card, and before triggering the first statistic operation and the acquisition operation when a frequency-doubled clock signal arrives, the method further includes: and acquiring a PPS signal of the SPAN-CPT by using a digital I/O acquisition card, and multiplying the PPS signal by frequency to obtain a frequency multiplication clock signal.
It should be noted that the second clock oscillator in the FPGA chassis is a high-precision clock oscillator, and the oscillation frequency is 40.
In the embodiment of the application, when the PPS signal of the inertial navigation system SPAN-CPT is received, the frequency is multiplied after one PPS signal is received every second.
An exemplary frequency multiplication schematic diagram of a pulse per second PPS signal is provided in the embodiments of the present application, as shown in fig. 2, a frequency of the PPS signal is 1Hz, a frequency of a frequency multiplication clock signal may be 1KHz, and a specific frequency of the frequency multiplication clock signal may be determined according to an actual situation, which is not limited herein.
It should be noted that, because the frequency multiplication is performed after one pulse per second PPS signal of the inertial navigation system is received by the digital I/O acquisition card, the clock crystal oscillator of the FPGA chassis is corrected once per second by the PPS pulse of the GPS, and the synchronization accuracy of the full-tensor magnetic data and the position and attitude data can be within 5 μ s by the synchronization method.
And S103, when the next frequency multiplication clock signal arrives, stopping the first statistic operation and acquiring the first vibration times of the first clock crystal oscillator, and stopping the second statistic operation and acquiring the second vibration times of the second clock crystal oscillator.
In this embodiment, when the next multiplied clock signal arrives, the data synchronization apparatus terminates the first statistical operation and obtains the first vibration times of the first clock oscillator, and terminates the second statistical operation and obtains the second vibration times of the second clock oscillator.
It should be noted that the first oscillation frequency of the first clock oscillator is the oscillation frequency generated between two frequency-doubled clock signals, and the second oscillation frequency of the second clock oscillator is the oscillation frequency generated between the arrival of the falling edge of the first clock oscillator and the arrival of the next frequency-doubled clock signal.
And S104, determining a resampling position of the full-tensor magnetic data by using the first vibration frequency, the second vibration frequency, the frequency multiplication clock signal and the sampling frequency, so as to realize data synchronization between the full-tensor magnetic data and the pose data of the SPAN-CPT based on the resampling position.
In the embodiment of the application, after the data synchronization device obtains the first vibration frequency and the second vibration frequency, the resampling position of the full-tensor magnetic data is determined by using the first vibration frequency, the second vibration frequency, the frequency multiplication clock signal and the sampling frequency, so that data synchronization between the full-tensor magnetic data and the pose data of the SPAN-CPT is realized based on the resampling position.
In this embodiment of the present application, the data synchronization apparatus further includes a serial port acquisition card, and the sampling frequency of the frequency-doubled clock signal is an integer multiple of the sampling frequency of the serial port acquisition card, and the method further includes: and acquiring the pose data of the SPAN-CPT by using the serial port acquisition card.
It should be noted that the pose data of the SPAN-CPT is the position and pose data of the SPAN-CPT.
It should be noted that the sampling frequency of the serial port acquisition card may be 50Hz, and the specific sampling frequency of the serial port acquisition card may be determined according to actual conditions, which is not limited herein in this embodiment of the present application.
In the embodiment of the present application, after determining the resampling position of the full-tensor magnetic data, the data synchronization apparatus further determines whether to use a bilinear interpolation method to obtain data corresponding to the resampling position according to the resampling position, where the bilinear interpolation method calculates data at the resampling position by weighting data around the resampling position.
Specifically, under the condition that the resampling position is an integer, the resampling full tensor magnetic data corresponding to the resampling position is searched from the full tensor magnetic data; under the condition that the resampling position is not an integer, taking the resampling position as a center, and acquiring a plurality of integer resampling positions; searching a plurality of re-sampling full-tensor magnetic data corresponding to a plurality of integer re-sampling positions from the full-tensor magnetic data; and obtaining the resampled full-tensor magnetic data by using the plurality of resampled full-tensor magnetic data.
Exemplarily, assuming that the calculated resampling position is 100, searching 100 th data from the full-tensor magnetic data, and taking the data as the resampling full-tensor magnetic data corresponding to the resampling position; assuming that the calculated resampling position is 100.5 at this time, and is not an integer position, and the data cannot be found from the full-tensor magnetic data, the surrounding integer resampling positions, for example, the integer resampling positions of 99 th, 100 th, 101 th, and 102 th, are obtained with the current resampling position 100.5 as the center, and the 99 th, 100 th, 101 th, and 102 th data are found from the full-tensor magnetic data, and the resampled full-tensor magnetic data is determined using the 99 th, 100 th, 101 th, and 102 th data.
It should be noted that, when determining that one resampled full-tensor magnetic data is determined using a plurality of resampled full-tensor magnetic data, a method of weighted averaging is required.
Specifically, according to the position relationship between a plurality of integer resampling positions and resampling positions, determining a plurality of weights corresponding to the plurality of integer resampling positions; and carrying out weighted average operation on the multiple resampled full-tensor magnetic data according to the weights to obtain the resampled full-tensor magnetic data.
For example, assuming that the current resampling position 100.5 is taken as the center at this time, the surrounding integer resampling positions, such as the integer resampling positions of 99 th, 100 th, 101 th and 102 th, it can be seen that 99 is farther from 100.5 than 100, and therefore the weight given to it may be lower than 100, the plurality of weights corresponding to the plurality of integer resampling positions are determined by the positional relationship with the resampling positions, and then the weighted average operation is performed on the plurality of resampled full-tensor magnetic data according to the weights, so as to obtain the resampled full-tensor magnetic data.
In this embodiment of the present application, the data synchronization apparatus further includes a serial port acquisition card, and the sampling frequency of the frequency-doubled clock signal is an integer multiple of the sampling frequency of the serial port acquisition card, and the method further includes: and (5) acquiring the pose data of the SPAN-CPT by using a serial port acquisition card.
It can be understood that, since the sampling frequency of the frequency-doubling clock signal is an integral multiple of the sampling frequency of the serial port acquisition card when acquiring the position and attitude data of the SPAN-CPT, and the sampling frequency of the frequency-doubling clock signal is assumed to be 1KHz, and the sampling frequency of the serial port acquisition card is 50Hz, after the resampling full-tensor magnetic data under the sampling frequency of 1KHz is obtained, the position and attitude data of the SPAN-CPT with the sampling frequency of 50Hz can be frequency-doubled, the position and attitude data with the same sampling frequency as the full-tensor magnetic data under the sampling frequency of 1KHz are obtained, and the data synchronization of the full-tensor magnetic data and the position and attitude data is realized.
It can be understood that, in order to realize the high-precision synchronism of the position and attitude data and the full-tensor magnetic data, firstly, the full-tensor magnetic data acquisition is triggered by utilizing a high-precision PPS signal provided by the SPAN-CPT, the synchronism of the full-tensor magnetic data with the position and attitude data acquisition is ensured, secondly, the recording and storing functions provided by the inertial navigation system SPAN-CPT are not used, but the position and attitude data of the inertial navigation system SPAN-CPT are read by utilizing a serial port acquisition card, the full-tensor magnetic data are read by an analog signal acquisition card, the two kinds of data are simultaneously transmitted to an FPGA case, the FPGA case can process the data in parallel, and meanwhile, a 40M clock crystal oscillator is arranged on the FPGA case, so that the full-tensor magnetic data at the whole millisecond position are obtained by utilizing the resampling principle of the two clock crystals and a bilinear interpolation method. In order to ensure that the crystal oscillator on the FPGA case does not generate accumulated errors, the PPS (pulse per second) of the GPS is used for correcting the crystal oscillator of the FPGA once every 1 second, and the synchronization method can ensure that the synchronization precision of the full-tensor magnetic data and the position and posture data is within 5 microseconds.
The embodiment of the application provides a data synchronization method, which comprises the following steps: when a frequency multiplication clock signal arrives, triggering a first statistic operation and an acquisition operation, wherein the first statistic operation is used for counting the vibration times of a first clock crystal oscillator in an analog signal acquisition card; the acquisition operation is used for acquiring full-tensor magnetic data based on the sampling frequency of the analog signal acquisition card; triggering a second statistical operation when the falling edge of the first clock crystal oscillator arrives, wherein the second statistical operation is used for counting the vibration times of a second clock crystal oscillator in the FPGA case; when the next frequency doubling clock signal arrives, stopping the first statistic operation and acquiring the first vibration times of the first clock crystal oscillator, stopping the second statistic operation and acquiring the second vibration times of the second clock crystal oscillator; determining a resampling position of the full-tensor magnetic data by utilizing the first vibration times, the second vibration times, the frequency multiplication clock signal and the sampling frequency so as to realize data synchronization between the full-tensor magnetic data and the pose data of the SPAN-CPT based on the resampling position; by adopting the implementation scheme, the resampling position of the full-tensor magnetic data under the frequency doubling clock signal can be calculated by counting the vibration times of the clock crystal oscillator of the analog signal acquisition card and the clock crystal oscillator of the FPGA case when the frequency doubling clock signal arrives, and the full-tensor magnetic data based on the GPS can be obtained because the frequency doubling clock signal is obtained based on the PPS signal of the GPS, so that the data synchronization between the full-tensor magnetic data and the pose data of the SPAN-CPT is realized.
Based on the foregoing embodiments, in another embodiment of the present application, a data synchronization apparatus is provided, where the data synchronization apparatus is connected to an inertial navigation system SPAN-CPT, and fig. 3 is a schematic connection diagram of the data synchronization apparatus provided in the present application, as shown in fig. 3, the data synchronization apparatus includes:
the compact reconfigurable input/output cRIO controller comprises a programmable gate array FPGA case and an analog signal acquisition card inserted into a first card slot of the FPGA case; the analog signal acquisition card comprises a first clock crystal oscillator, and the FPGA case comprises a second clock crystal oscillator;
wherein,
the analog signal acquisition card is configured to trigger a first statistic operation and an acquisition operation when a frequency multiplication clock signal arrives, wherein the first statistic operation is used for counting the vibration times of a first clock crystal oscillator; the acquisition operation is used for acquiring full-tensor magnetic data based on the sampling frequency of the analog signal acquisition card, terminating the first statistic operation and acquiring the first vibration times of the first clock crystal oscillator when the next frequency doubling clock signal arrives, and transmitting the first vibration times to the cRIO controller;
the FPGA case is configured to trigger a second statistical operation when the falling edge of the first clock crystal oscillator arrives, wherein the second statistical operation is used for counting the vibration times of the second clock crystal oscillator, and when the next frequency doubling clock signal arrives, the second statistical operation is stopped, and the second vibration times of the second clock crystal oscillator are obtained and transmitted to the cRIO controller;
and the cRIO controller is configured to determine a resampling position of the full-tensor magnetic data by utilizing the first vibration times, the second vibration times, the frequency multiplication clock signal and the sampling frequency of the analog signal acquisition card so as to realize data synchronization between the full-tensor magnetic data and the pose data of the SPAN-CPT based on the resampling position.
The data synchronization device provided by the embodiment of the application is suitable for a scene of carrying out data synchronization on full-tensor magnetic data, position data and attitude data in an aeromagnetic superconducting full-tensor gradient measurement and control system.
In this embodiment of the present application, the data synchronization apparatus further includes: a digital input/output I/O acquisition card is inserted into a second clamping groove of the FPGA case; the digital I/O acquisition card is configured to acquire a PPS signal of the SPAN-CPT, and frequency-doubled PPS signal is obtained after frequency doubling.
In this embodiment of the present application, the data synchronization apparatus further includes: a serial port acquisition card is inserted into a third card slot of the FPGA case; the sampling frequency of the frequency multiplication clock signal is an integral multiple of the sampling frequency of the serial port acquisition card; the serial port acquisition card is configured to acquire pose data of the SPAN-CPT.
In an embodiment of the present application, the analog signal acquisition card is further configured to acquire full tensor magnetic data using the first 9 channels of the analog signal acquisition card.
In the embodiment of the application, the analog signal acquisition card is NI 9202; the digital I/O acquisition card is NI 9467; the serial port acquisition card is NI 9870.
It can be understood that the position and attitude data of the inertial navigation system SPAN-CPT are read by the serial port acquisition card NI9870, the recording and storing functions provided by the inertial navigation system SPAN-CPT are not used, and the synchronism of the full-tensor magnetic data and the start of the position and attitude data acquisition is ensured.
In the embodiment of the application, the working mode of the differential GPS is adopted when the PPS signal of SPAN-CPT is received, so that the measurement accuracy of position and attitude data can be improved.
In the embodiment of the application, the FPGA chassis is a four-slot FPGA chassis, and the NI9202, NI9467 and NI9870 are inserted into the first three card slots of the FPGA chassis.
In the present embodiment, NI9870 is also configured to receive the full tensor magnetic signal with the first 9 channels of NI 9870; the full tensor magnetic signal includes a 6-channel magnetic gradient signal and a 3-channel magnetometer signal;
in the present embodiment, NI9467 is also configured to receive PPS signals using the first channel of NI 9467.
In the embodiment of the present application, the oscillation frequency of the first clock oscillator in the analog signal acquisition card is 12.8.
In the embodiment of the present application, the second clock oscillator in the FPGA chassis is a high-precision clock oscillator, and the oscillation frequency is 40.
The embodiment of the present application provides an exemplary data synchronization implementation procedure, as follows:
step 1, respectively inserting an analog signal acquisition card NI9202, a digital I/O acquisition card NI9467 and a serial port acquisition card NI9870 into the first three card slots of the FPGA case.
And 2, connecting 9-channel full tensor magnetic signals to the first 9 channels of the NI9202, connecting the position and attitude data of the SPAN-CPT of the inertial navigation system to the first channel of the NI9870 module, and simultaneously connecting the PPS signals of the SPAN-CPT of the inertial navigation system to the first channel of the NI 9467.
And 3, after all hardware connection is finished, supplying power to the whole system, after the power is on, waiting for convergence of position and attitude data of the SPAN-CPT of the inertial navigation system, wherein the data synchronization algorithm can only realize data synchronization after the convergence, otherwise, a clock used by the synchronization algorithm is not a PPS clock of the position and attitude data, and the data synchronization precision is reduced.
And 4, acquiring position and attitude data of the combined inertial navigation by using a serial port acquisition card NI9870 by using a sampling frequency of 50Hz, wherein each piece of inertial navigation data is provided with the GPS time of the inertial navigation.
And 5, receiving one PPS pulse every second by the digital I/O acquisition card NI9467, and then carrying out frequency multiplication on the PPS pulse on software to generate a frequency multiplication clock signal of 1KHz, wherein the sampling frequency of 1KHz is a sampling position in a resampling algorithm, and the unit of the sampling position is the number of sampling points as shown in figure 2.
And 6, acquiring a full tensor magnetic signal by using an analog signal acquisition card NI9202 at a sampling frequency of 6.25KHz, converting the full tensor magnetic signal into full tensor magnetic data, and setting the clock crystal oscillator of the NI9202 to be 12.8M.
And 7, calculating a resampling position on software according to a frequency doubling clock signal, the sampling frequency of 6.25KHz of the analog signal acquisition card NI9202, the clock crystal oscillator 12.8M of the analog signal acquisition card NI9202 and the high-precision clock crystal oscillator 40M of the FPGA case, wherein the calculating method comprises the following steps:
(1) the frequency of the frequency doubling clock signal is 1KHz, the sampling frequency of the analog signal acquisition card NI9202 is 6.25KHz, the clock crystal oscillator of the NI9202 is 12.8M, and the high-precision clock crystal oscillator of the FPGA case is 40M;
(2) temporarily calculating the vibration times N of the clock crystal oscillator of the analog signal acquisition card NI9202 and the vibration times N of the high-precision clock crystal oscillator of the FPGA case when a frequency multiplication clock signal comes, wherein N is calculated temporarily at the frequency multiplication clock signal, N is calculated temporarily at the falling edge of the clock crystal oscillator of the analog signal acquisition card NI9202 until the next frequency multiplication clock signal comes and is cut off temporarily, and the resampling position can be calculated according to the two values, and the calculation formula is as follows:
N×6250/12.8M+n×6250/40M (1)
(3) assuming that N passes 12.8M, N is 0, and is substituted into equation (2) when the full tensor magnetic data of the 1 st s is to be obtained:
12.8M×6250/12.8M+0×6250/40M=6250 (2)
the resample location corresponding to the full tensor magnetic data point from equation 1s above is the 6250 th data point for full tensor magnetic data.
(4) When the resampling position is not an integer, it is necessary to obtain the data corresponding to the sampling position by using bilinear interpolation, where the bilinear interpolation is to calculate the required data by weighting the data around the sampling point, for example, the calculated resampling position is 100.5, and the data acquired by the NI9202 module does not have data at 100.5, then it is necessary to read the data X at 99 th, 100 th, 101 th, and 102 th positions99、X100、X101、X102Then, data X at the resampling position of 100.5100.5Is composed of
X100.5=(2X99+4X100+4X101+2X102)/12 (3)
And 8, obtaining the full tensor magnetic data under the 1KHz sampling frequency through the step 7, and writing the time of the first data in the data file into the stored file when the full tensor magnetic data are stored, so that each full tensor magnetic data has a PPS time stamp based on the GPS.
It can be understood that, because the frequency of the sampling signal is an integral multiple of the second sampling frequency when the position and attitude data of the combined inertial navigation is acquired, after the full tensor magnetic data under the sampling frequency of 1KHz is obtained, the position and attitude data of the combined inertial navigation can be multiplied to obtain the position and attitude data with the same sampling frequency as the full tensor magnetic data under the sampling frequency of 1KHz, and the data synchronization of the full tensor magnetic data and the position and attitude data is realized.
The embodiment of the application provides a data synchronization device, and the device comprises: the cRIO controller comprises an FPGA case and an analog signal acquisition card inserted into a first card slot of the FPGA case; the analog signal acquisition card comprises a first clock crystal oscillator, and the FPGA case comprises a second clock crystal oscillator; the analog signal acquisition card is configured to trigger a first statistic operation and an acquisition operation when a frequency multiplication clock signal arrives, wherein the first statistic operation is used for counting the vibration times of a first clock crystal oscillator; the acquisition operation is used for acquiring full-tensor magnetic data based on the sampling frequency of the analog signal acquisition card, terminating the first statistic operation and acquiring the first vibration times of the first clock crystal oscillator when the next frequency doubling clock signal arrives, and transmitting the first vibration times to the cRIO controller; the FPGA case is configured to trigger a second statistical operation when the falling edge of the first clock crystal oscillator arrives, wherein the second statistical operation is used for counting the vibration times of the second clock crystal oscillator, and when the next frequency doubling clock signal arrives, the second statistical operation is stopped, and the second vibration times of the second clock crystal oscillator are obtained and transmitted to the cRIO controller; and the cRIO controller is configured to determine a resampling position of the full-tensor magnetic data by utilizing the first vibration times, the second vibration times, the frequency multiplication clock signal and the sampling frequency of the analog signal acquisition card so as to realize data synchronization between the full-tensor magnetic data and the pose data of the SPAN-CPT based on the resampling position. By adopting the implementation scheme, the resampling position of the full-tensor magnetic data under the frequency doubling clock signal can be calculated by counting the vibration times of the clock crystal oscillator of the analog signal acquisition card and the clock crystal oscillator of the FPGA case when the frequency doubling clock signal arrives, and the full-tensor magnetic data based on the GPS can be obtained because the frequency doubling clock signal is obtained based on the PPS signal of the GPS, so that the data synchronization between the full-tensor magnetic data and the pose data of the SPAN-CPT is realized.
As will be appreciated by one skilled in the art, embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of a hardware embodiment, a software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, optical storage, and the like) having computer-usable program code embodied therein.
The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.
These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.
The above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention.
Claims (12)
1. A data synchronization method is applied to a data synchronization device, the data synchronization device is connected with an inertial navigation system SPAN-CPT, the data synchronization device comprises a Field Programmable Gate Array (FPGA) case, an analog signal acquisition card is inserted into a first card slot of the FPGA case, and the method comprises the following steps:
when a frequency doubling clock signal arrives, triggering a first statistic operation and an acquisition operation, wherein the first statistic operation is used for counting the vibration times of a first clock crystal oscillator in the analog signal acquisition card; the acquisition operation is used for acquiring full-tensor magnetic data based on the sampling frequency of the analog signal acquisition card;
triggering a second statistical operation when the falling edge of the first clock crystal oscillator arrives, wherein the second statistical operation is used for counting the vibration times of a second clock crystal oscillator in the FPGA case;
when the next frequency doubling clock signal arrives, stopping the first statistic operation and acquiring the first vibration times of the first clock crystal oscillator, stopping the second statistic operation and acquiring the second vibration times of the second clock crystal oscillator;
and determining a resampling position of the full-tensor magnetic data by using the first vibration times, the second vibration times, the frequency multiplication clock signal and the sampling frequency so as to realize data synchronization between the full-tensor magnetic data and the pose data of the SPAN-CPT based on the resampling position.
2. The method of claim 1, wherein the data synchronization device further comprises a digital input/output I/O acquisition card, and wherein before triggering the first statistical operation and the acquisition operation when a multiplied clock signal arrives, the method further comprises:
and acquiring the PPS signal of the SPAN-CPT by using the digital I/O acquisition card, and performing frequency multiplication on the PPS signal to obtain a frequency multiplication clock signal.
3. The method of claim 1, wherein after determining the resampling location for the full-tensor magnetic data using the first number of oscillations, the second number of oscillations, the multiplied clock signal, and the sampling frequency, the method further comprises:
under the condition that the resampling positions are integers, searching the resampling full tensor magnetic data corresponding to the resampling positions from the full tensor magnetic data;
under the condition that the resampling positions are not integers, taking the resampling positions as a center, and acquiring a plurality of integer resampling positions; searching a plurality of re-sampling full tensor magnetic data corresponding to the integer re-sampling positions from the full tensor magnetic data;
and obtaining the resampled full tensor magnetic data by using the plurality of resampled full tensor magnetic data.
4. The method of claim 3, wherein said utilizing said plurality of resampled full tensor magnetic data to obtain said resampled full tensor magnetic data comprises:
determining a plurality of weights corresponding to the plurality of integer resampling positions according to the position relation between the plurality of integer resampling positions and the resampling position;
and carrying out weighted average operation on the multiple pieces of resampled full-tensor magnetic data according to the multiple weights to obtain the resampled full-tensor magnetic data.
5. The method according to claim 1, wherein the data synchronization device further comprises a serial port acquisition card, and the sampling frequency of the frequency-doubled clock signal is an integer multiple of the sampling frequency of the serial port acquisition card, and the method further comprises:
and acquiring the pose data of the SPAN-CPT by using the serial port acquisition card.
6. A data synchronization device, wherein the data synchronization device is connected to an inertial navigation system SPAN-CPT, the device comprising:
the system comprises a compact reconfigurable input/output (cRIO) controller, a signal processing module and a signal processing module, wherein the cRIO controller comprises a programmable gate array (FPGA) case, and an analog signal acquisition card is inserted into a first card slot of the FPGA case; the analog signal acquisition card comprises a first clock crystal oscillator, and the FPGA case comprises a second clock crystal oscillator;
wherein,
the analog signal acquisition card is configured to trigger a first statistic operation and an acquisition operation when a frequency multiplication clock signal arrives, wherein the first statistic operation is used for counting the vibration times of the first clock crystal oscillator; the acquisition operation is used for acquiring full-tensor magnetic data based on the sampling frequency of the analog signal acquisition card, and when the next frequency doubling clock signal arrives, the first statistic operation is stopped, the first vibration frequency of the first clock crystal oscillator is acquired, and the first vibration frequency is transmitted to the cRIO controller;
the FPGA case is configured to trigger a second statistical operation when a falling edge of the first clock crystal oscillator arrives, wherein the second statistical operation is used for counting the vibration times of the second clock crystal oscillator, and when a next frequency doubling clock signal arrives, the second statistical operation is terminated, and the second vibration times of the second clock crystal oscillator are obtained and transmitted to the cRIO controller;
the cRIO controller is configured to determine a resampling position of the full-tensor magnetic data by using the first vibration times, the second vibration times, the frequency multiplication clock signal and the sampling frequency of the analog signal acquisition card, so as to realize data synchronization between the full-tensor magnetic data and the pose data of the SPAN-CPT based on the resampling position.
7. The apparatus of claim 6, wherein the apparatus comprises: a digital input/output I/O acquisition card is inserted into a second clamping groove of the FPGA case;
the digital I/O acquisition card is configured to acquire a PPS signal of the SPAN-CPT, and frequency-doubled the PPS signal to obtain a frequency-doubled clock signal.
8. The apparatus of claim 6, wherein the apparatus comprises: a serial port acquisition card is inserted into a third card slot of the FPGA case; the sampling frequency of the frequency multiplication clock signal is an integral multiple of the sampling frequency of the serial port acquisition card;
the serial port acquisition card is configured to acquire the pose data of the SPAN-CPT.
9. The apparatus of claim 6, wherein said analog signal acquisition card is further configured to acquire said full tensor magnetic data using the first 9 channels of said analog signal acquisition card.
10. The apparatus of claim 6, wherein said analog signal acquisition card is NI 9202.
11. The apparatus of claim 7, wherein said digital I/O acquisition card is NI 9467.
12. The apparatus of claim 8, wherein said serial port acquisition card is NI 9870.
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