Disclosure of Invention
The invention aims to solve the problems of inconsistent spatial resolution, data distortion, systematic deviation and low operation efficiency caused by deviation of the navigational speed from a set value and fluctuation during operation. Therefore, the invention provides a navigation method, a navigation system, navigation equipment and a navigation product of the unmanned platform gravity measurement carrier, which can support the unmanned platform small-sized gravity meter to automatically monitor the measurement working condition, reasonably set the working navigational speed, improve the dynamic environment adaptability and the measurement precision of the unmanned platform gravity measurement and realize the efficient and high-data quality unmanned platform gravity measurement operation.
The invention provides a navigation method of an unmanned platform gravity measurement carrier, which adopts the following technical scheme: comprising the following steps:
Acquiring GNSS satellite navigation information and gravimeter output information in real time in the operation process of the unmanned platform gravity measurement carrier;
calculating to obtain gravity abnormal value information according to the GNSS satellite navigation information and the gravity meter output information;
calculating to obtain motion acceleration information according to GNSS satellite navigation information of the current period;
According to the motion acceleration information and the gravity abnormal value information corresponding to time, calculating to obtain a coherence function value at each frequency point by using an amplitude coherence function, and then calculating to obtain the maximum value of the mean absolute value of the coherence function value at each frequency point;
And calculating the operation navigational speed of the unmanned platform gravity measurement carrier in the next period according to the maximum value and the current operation navigational speed of the unmanned platform gravity measurement carrier.
Further, according to the GNSS satellite navigation information and the gravity meter output information, the process of calculating the gravity anomaly information is:
Based on position information, east speed, north speed and sky speed in GNSS satellite navigation information, calculating a Hertefose correction value, a normal gravity correction value, a horizontal acceleration correction value and a vertical acceleration correction value at each sampling moment; then respectively using cut-off frequenciesFiltering is carried out on the FIR low-pass filter to obtain a filtered value of the Hertefose correction value, a filtered value of the normal gravity correction value, a filtered value of the horizontal acceleration correction value and a filtered value of the vertical acceleration correction value;
Cut-off frequencyThe calculation formula of (2) is as follows:
wherein,Represents a cut-off frequency; representing the current operation navigational speed; representing spatial resolution;
Respectively filtering east-direction original specific force, north-direction original specific force and sky-direction original specific force in the gravity meter output information by using anti-aliasing FIR low-pass filters, respectively extracting, and adjusting the sampling rate to be the same as that of the GNSS satellite navigation information; then respectively using cut-off frequencyFiltering is carried out on the FIR low-pass filter to obtain a filter value of east specific force, a filter value of north specific force and a filter value of sky specific force;
And calculating to obtain the gravity anomaly value information at each sampling moment according to the filter value of the east-direction specific force, the filter value of the north-direction specific force and the filter value of the sky-direction specific force, the filter value of the early gravity correction value, the filter value of the normal gravity correction value, the filter value of the horizontal acceleration correction value and the filter value of the vertical acceleration correction value.
Further, the sampling rate of the GNSS satellite navigation information is 1Hz; the sampling rate of the output information of the gravimeter is 100Hz.
Further, according to the GNSS satellite navigation information of the current period, the process of calculating the motion acceleration information is as follows:
Respectively performing differential processing on the east velocity, the north velocity and the sky velocity in the GNSS satellite navigation information, and then respectively using cut-off frequenciesFiltering by an FIR low-pass filter to obtain motion acceleration information, wherein the motion acceleration information comprises a filtered value of east acceleration, a filtered value of north acceleration and a filtered value of sky acceleration;
Cut-off frequencyThe calculation formula of (2) is as follows:
wherein,Represents a cut-off frequency; representing the current operation navigational speed; representing the spatial resolution.
Further, the cycle is half an hour.
Further, according to the motion acceleration information and the gravity abnormal value information corresponding to time, a process of calculating a coherence function value at each frequency point by using an amplitude coherence function and then calculating a maximum value of an average value of the coherence function values at each frequency point is as follows:
respectively calculating amplitude coherence function values between the gravity abnormal value information and the east acceleration filter value, the north acceleration filter value and the sky acceleration filter value of corresponding time in the frequency range of 0.001 Hz-1 Hz to obtain、、Wherein, the method comprises the steps of, wherein,An amplitude coherence function value between the gravity anomaly value information and the filtered value of the east acceleration at each frequency point,An amplitude coherence function value between the gravity outlier information and the filtered value of the north acceleration at each frequency point,Amplitude coherence function values between the gravity abnormal value information and the filtered value of the natural acceleration at each frequency point are represented;
According to、、Respectively calculating to obtain、、Wherein, the method comprises the steps of, wherein,Representation ofAbsolute value of the mean value of (2); Representation ofAbsolute value of the mean value of (2); Representation ofAbsolute value of the mean value of (2);
Calculating the maximum value of the mean value absolute value of the coherence function value at each frequency point, wherein the calculation formula is as follows:
wherein,The maximum value is indicated and the maximum value,Representing a maximum value.
Further, the calculation formula of the operation navigational speed in the next period is as follows:
wherein,Indicating the operational speed of the next cycle.
The invention also provides a navigation system of the unmanned platform gravity measurement carrier, which adopts the following technical scheme: comprising the following steps: the data acquisition module is respectively connected with the gravity abnormal value information calculation module and the motion acceleration information calculation module, the coherence function calculation module is respectively connected with the gravity abnormal value information calculation module, the motion acceleration information calculation module and the operation navigational speed calculation module,
The data acquisition module is used for acquiring GNSS satellite navigation information and gravimeter output information in real time in the operation process of the unmanned platform gravity measurement carrier;
the gravity abnormal value information calculation module is used for calculating the gravity abnormal value information according to the GNSS satellite navigation information and the gravity meter output information;
The motion acceleration information calculation module is used for calculating motion acceleration information according to GNSS satellite navigation information of the current period;
the coherence function calculation module is used for calculating a coherence function value at each frequency point by using an amplitude coherence function according to the motion acceleration information and the gravity abnormal value information corresponding to time, and then calculating a maximum value of an average value absolute value of the coherence function value at each frequency point;
the operation navigational speed calculation module is used for calculating the operation navigational speed of the unmanned platform gravity measurement carrier in the next period according to the maximum value and the current operation navigational speed of the unmanned platform gravity measurement carrier.
The invention also provides computer equipment, which comprises a memory and a processor, wherein the memory stores a computer program, and the processor realizes the navigation method of the unmanned platform gravity measurement carrier when executing the computer program.
The invention also provides a computer program product, which comprises a computer program, wherein the computer program realizes the navigation method of the unmanned platform gravity measurement carrier when being executed by a processor.
The above technical solutions in the embodiments of the present invention have at least one of the following technical effects:
According to the invention, the operation navigational speed of the unmanned platform gravity measurement carrier is dynamically regulated and controlled according to the correlation of the gravity abnormal value information obtained by real-time data processing and the three-dimensional motion acceleration information obtained by periodic processing, the real-time monitoring and adaptation of dynamic measurement working conditions can be realized, the problems of inconsistent spatial resolution, distortion of gravity information, systematic deviation, low operation efficiency and the like caused by deviation of the carrier navigational speed from a set value and fluctuation are solved, and the high efficiency and the consistency of data quality of the unmanned platform gravity measurement are ensured.
Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.
Detailed Description
For the purpose of making the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings, and it is apparent that the described embodiments are some embodiments of the present invention, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention. The following examples are illustrative of the invention but are not intended to limit the scope of the invention.
In the description of the present specification, a description referring to terms "one embodiment," "some embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the embodiments of the present invention. In this specification, schematic representations of the above terms are not necessarily directed to the same embodiment or example. Furthermore, the particular features, structures, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, the different embodiments or examples described in this specification and the features of the different embodiments or examples may be combined and combined by those skilled in the art without contradiction.
The following describes the navigation method, system, device and product of the unmanned platform gravity measurement carrier according to the present invention in further detail with reference to fig. 1 to 3:
In this embodiment, as shown in fig. 1, a navigation method of an unmanned platform gravity measurement carrier is provided, which includes the following steps:
Step 1: and in the operation process of the unmanned platform gravity measurement carrier, acquiring GNSS satellite navigation information and gravimeter output information in real time.
Before the unmanned platform gravity measurement carrier works, the initial navigational speed of the work is set according to the spatial resolution requirement of the work and the on-site working condition. The initial speed is used as the current operation speed of the unmanned platform gravity measurement carrier in the first period of the operation process. For unmanned platform gravity measurement carrier, a large number of gravity measurement experiments show that 5 sections of navigational speeds have strong adaptability to working conditions, have high operation efficiency, and are suitable for being used as the set value of the initial navigational speed.
In the operation process, the gravity meter display control computer collects GNSS satellite navigation information in real time at a sampling rate of 1Hz, and simultaneously collects gravity meter output information in real time at a sampling rate of 100Hz, and the information is stored in a data file of the gravity meter display control computer. The GNSS satellite navigation information comprises position information, east speed, north speed and sky speed; the gravity meter output information comprises east to primary specific force, north to primary specific force and sky to primary specific force.
Step 2: and calculating to obtain the gravity anomaly value information according to the GNSS satellite navigation information and the gravity meter output information.
The GNSS satellite navigation information is processed by the following specific processes:
Based on the position information, the east speed, the north speed and the sky speed, calculating a Hertefose correction value, a normal gravity correction value, a horizontal acceleration correction value and a vertical acceleration correction value at each sampling time; then apply cut-off frequency to the four correction values respectivelyAnd (3) filtering the FIR low-pass filter to obtain a filtered value of the Hertefose correction value, a filtered value of the normal gravity correction value, a filtered value of the horizontal acceleration correction value and a filtered value of the vertical acceleration correction value.
The output information of the gravimeter is processed, and the specific process is as follows:
Respectively filtering east-direction original specific force, north-direction original specific force and sky-direction original specific force by using anti-aliasing FIR low-pass filters with cut-off frequency of 0.3Hz, respectively extracting filtered data, and adjusting the sampling rate to be the same as the sampling rate of the GNSS satellite navigation information, namely reducing the sampling rate to be 1Hz; then respectively using cut-off frequencyIs filtered by the FIR low-pass filter of (c), and obtaining the filtered value of the east-direction specific force, the filtered value of the north-direction specific force and the filtered value of the sky-direction specific force.
The filter processing is carried out by an IIR low-pass filter which is different from the IIR low-pass filter which is usually used in the off-line processing, and the nonlinearity of the phase of the IIR filter is corrected by bidirectional filtering. The invention processes the FIR low-pass filter in real time, the FIR filter has linear phase characteristic, ensures that each corrected value and specific force information waveform after the filtering process are not distorted, has consistent delay time, and plays a key role in the real-time high-precision processing of the gravity data.
The calculation process of the gravity abnormal value information comprises the following steps:
And calculating to obtain the gravity anomaly value information at each sampling moment according to the filter value of the east-direction specific force, the filter value of the north-direction specific force and the filter value of the sky-direction specific force, the filter value of the early gravity correction value, the filter value of the normal gravity correction value, the filter value of the horizontal acceleration correction value and the filter value of the vertical acceleration correction value. The specific calculation process of the gravity anomaly value information is the prior art, and will not be described herein.
The method is used for processing the GNSS satellite navigation information and the output information of the gravimeter acquired in real time, and the real-time processing is carried out in the whole operation process of the unmanned platform gravity measurement carrier.
Cut-off frequency of FIR low-pass filterThe calculation formula is as follows, which is related to the current operation navigational speed and the spatial resolution:
wherein,Represents the cut-off frequency in Hz; Representing the current operation navigational speed in units of m/s; representing spatial resolution, unit m.
Step 3: and calculating to obtain the motion acceleration information according to the GNSS satellite navigation information of the current period.
The specific process is as follows: respectively carrying out differential processing on the east velocity, the north velocity and the sky velocity in the GNSS satellite navigation information to obtain east acceleration, north acceleration and sky acceleration, and then respectively using cut-off frequenciesThe FIR low-pass filter of the system is used for filtering to obtain motion acceleration information, wherein the motion acceleration information comprises a filtered value of east acceleration, a filtered value of north acceleration and a filtered value of natural acceleration.
The step periodically calculates motion acceleration information, illustratively, in half an hour period. For example, after the unmanned platform gravity measurement carrier starts to work and the half-hour GNSS satellite navigation information is collected, the first period of motion acceleration information is calculated based on the half-hour east, north and sky speeds collected. The unmanned platform gravity measurement vehicle continues to operate for 1 hour, calculating motion acceleration information for a second period based on the east, north and heaven speeds from half an hour to 1 hour (second half an hour).
Step 4: and according to the motion acceleration information and the gravity abnormal value information corresponding to time, calculating by using an amplitude coherence function to obtain a coherence function value, and then calculating to obtain the maximum value of the mean absolute value of the coherence function value at each frequency point.
The specific process is as follows: respectively calculating amplitude coherence function values between the gravity abnormal value information and the east acceleration filter value, the north acceleration filter value and the sky acceleration filter value in the frequency range of 0.001 Hz-1 Hz to obtain、、Wherein, the method comprises the steps of, wherein,An amplitude coherence function value between the gravity anomaly value information and the filtered value of the east acceleration at each frequency point,An amplitude coherence function value between the gravity outlier information and the filtered value of the north acceleration at each frequency point,And the amplitude coherence function value between the gravity abnormal value information and the filtered value of the natural acceleration at each frequency point is represented.
The target frequency interval is set to be 0.001 Hz-1 Hz, and is obtained after analysis of a large number of unmanned platform gravity measurement test data, and in the frequency interval, the signal-to-noise ratio of the gravity anomaly signal and noise is high, so that the frequency interval is the main frequency band for effective gravity anomaly information distribution.
Amplitude coherence functionThe calculation formula of (2) is as follows:
wherein,Representing signalsSelf-power spectrum, unit；Representing signalsSelf-power spectrum, unit；Representing signalsAnd (3) withCross-power spectrum of (2) units；Represents the frequency of the signal, in Hz,. Each frequency point and signal frequency in this stepCorresponding to each value of (a) in the set.
According to、、Respectively calculating to obtain、、Wherein, the method comprises the steps of, wherein,Representation ofAbsolute value of the mean value of (2); Representation ofAbsolute value of the mean value of (2); Representation ofAbsolute value of the mean value of (c).
The maximum value of the mean absolute value of the three coherence function values at each frequency point is calculated according to the following formula:
wherein,The maximum value is indicated and the maximum value,Representing a maximum value.
Step 5: and calculating the operation navigational speed of the unmanned platform gravity measurement carrier in the next period according to the maximum value and the current operation navigational speed of the unmanned platform gravity measurement carrier.
The calculation formula of the operation navigational speed of the next period is as follows:
wherein,Representing the operation navigational speed of the next period, wherein the unit is m/s; Indicating the current speed of the operation in m/s.
The cut-off frequency of the FIR low-pass filterIs related to the current operation navigational speed and the spatial resolution. The step calculates the operation navigational speed of the next period, and the cut-off frequency is realized when the GNSS satellite navigation information and the gravity meter output information which are acquired in real time in the next period are filteredCan be adjusted according to the operation navigational speed.
Step 3, motion acceleration information is calculated periodically, and corresponding step 4 and step 5 are also calculated periodically. The steps 1 and 2 are executed in real time during the operation of the unmanned platform gravity measurement carrier, and the steps 3 to 5 are executed reciprocally with a period of half an hour. And (3) calculating the operation navigational speed of the next period every time the steps 3 to 5 are executed, so that the operation navigational speed of the unmanned platform gravity measurement carrier is adjusted, the cut-off frequency of an FIR low-pass filter used in the process of filtering GNSS satellite navigation information and output information of the gravity meter is influenced, the calculated gravity anomaly value information is influenced, the dynamic environment adaptability and measurement precision of the unmanned platform gravity measurement are improved, and the efficient and high-data-quality unmanned platform gravity measurement operation is realized.
Taking the unmanned ship loading force measurement operation as an example, the gravity anomaly comparison graph of the measuring line obtained by the traditional method and the method is shown in fig. 2, the gravity anomaly curve obtained by the method is smoother on the whole, the gravity information distortion is obviously improved, and the consistency of the data quality is higher.
In this embodiment, as shown in fig. 3, a navigation system of an unmanned platform gravity measurement carrier is further provided, and the following technical scheme is adopted: comprising the following steps: the device comprises a data acquisition module 1, a gravity abnormal value information calculation module 2, a motion acceleration information calculation module 3, a coherent function calculation module 4 and a working navigational speed calculation module 5, wherein the data acquisition module 1 is respectively connected with the gravity abnormal value information calculation module 2 and the motion acceleration information calculation module 3, and the coherent function calculation module 4 is respectively connected with the gravity abnormal value information calculation module 2, the motion acceleration information calculation module 3 and the working navigational speed calculation module 5.
The data acquisition module 1 is used for acquiring GNSS satellite navigation information and gravimeter output information in real time in the operation process of the unmanned platform gravity measurement carrier; the GNSS satellite navigation information comprises position information, east speed, north speed and sky speed; the gravity meter output information comprises east to primary specific force, north to primary specific force and sky to primary specific force.
The gravity anomaly value information calculation module 2 is configured to calculate gravity anomaly value information according to the GNSS satellite navigation information and the gravity meter output information. The gravity anomaly value information calculating module 2 reads position information, east direction speed, north direction speed and sky direction speed, and east direction original specific force, north direction original specific force and sky direction original specific force from the data collecting module 1.
The GNSS satellite navigation information is processed by the following specific processes:
Based on the position information, the east speed, the north speed and the sky speed, calculating a Hertefose correction value, a normal gravity correction value, a horizontal acceleration correction value and a vertical acceleration correction value at each sampling time; then apply cut-off frequency to the four correction values respectivelyAnd (3) filtering the FIR low-pass filter to obtain a filtered value of the Hertefose correction value, a filtered value of the normal gravity correction value, a filtered value of the horizontal acceleration correction value and a filtered value of the vertical acceleration correction value.
The output information of the gravimeter is processed, and the specific process is as follows:
Respectively filtering east-direction original specific force, north-direction original specific force and sky-direction original specific force by using anti-aliasing FIR low-pass filters with cut-off frequency of 0.3Hz, respectively extracting filtered data, and adjusting the sampling rate to be the same as the sampling rate of the GNSS satellite navigation information, namely reducing the sampling rate to be 1Hz; then respectively using cut-off frequencyIs filtered by the FIR low-pass filter of (c), and obtaining the filtered value of the east-direction specific force, the filtered value of the north-direction specific force and the filtered value of the sky-direction specific force.
The calculation process of the gravity abnormal value information comprises the following steps:
And calculating to obtain the gravity anomaly value information at each sampling moment according to the filter value of the east-direction specific force, the filter value of the north-direction specific force and the filter value of the sky-direction specific force, the filter value of the early gravity correction value, the filter value of the normal gravity correction value, the filter value of the horizontal acceleration correction value and the filter value of the vertical acceleration correction value.
The motion acceleration information calculating module 3 is configured to calculate motion acceleration information according to GNSS satellite navigation information in a current period.
After starting the operation, the motion acceleration information calculating module 3 counts time, reads the east speed, the north speed and the sky speed of the current period from the data collecting module 1 when each period is finished, respectively performs differential processing to obtain the east acceleration, the north acceleration and the sky acceleration, and then respectively uses the cut-off frequencyThe FIR low-pass filter of the system is used for filtering to obtain motion acceleration information, wherein the motion acceleration information comprises a filtered value of east acceleration, a filtered value of north acceleration and a filtered value of natural acceleration. The motion acceleration information is sent to the coherence function computation module 4.
The coherence function calculation module 4 is configured to calculate, according to the motion acceleration information and the gravity outlier information corresponding to the time, a coherence function value at each frequency point by using an amplitude coherence function, and then calculate a maximum value of an absolute value of a mean value of the coherence function value at each frequency point.
After the coherence function calculation module 4 receives the motion acceleration information, acquiring the gravity abnormal value information corresponding to time from the gravity abnormal value information calculation module 2, then calculating amplitude coherence function values between the gravity abnormal value information and the east acceleration filter value, between the north acceleration filter value and the sky acceleration filter value in the frequency range of 0.001 Hz-1 Hz respectively, then calculating absolute values of means corresponding to the three amplitude coherence function values respectively, and finally calculating the maximum value of the means absolute values of the three coherence function values at each frequency point. The maximum value is sent to the operation navigational speed calculating module 5.
And the operation navigational speed calculating module 5 is used for calculating the operation navigational speed of the unmanned platform gravity measuring carrier in the next period according to the maximum value and the current operation navigational speed of the unmanned platform gravity measuring carrier. And after receiving the maximum value, the operation navigational speed calculation module 5 calculates the operation navigational speed of the next period by combining the current operation navigational speed of the unmanned platform gravity measurement carrier, and sends the operation navigational speed to the unmanned platform gravity measurement carrier control system to adjust the operation navigational speed.
In this embodiment, a computer device is further provided, including a memory and a processor, where the memory stores a computer program, and the processor implements the navigation method of the unmanned platform gravity measurement carrier when executing the computer program.
In this embodiment, a computer program product is also provided, including a computer program that, when executed by a processor, implements a method for navigating an unmanned platform gravity measurement vehicle as described above.
Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present invention, and are not limiting; although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present invention.