CN111562600B - Precision calibration system and calibration method - Google Patents

Abstract

The invention relates to the technical field of satellite navigation, and provides a precision calibration system for performing precision calibration on an intelligent GNSS code table in a simulation environment, which comprises the following steps: the satellite signal simulator simulates navigation data of a satellite navigation system and provides corresponding radio frequency signals; a reference frequency scale providing a time-based reference signal to the satellite signal simulator; the test scene module provides a preset motion trail and limiting condition selection; the navigation signal control module controls the output of the satellite signal simulator and controls the calling of the test scene module; and the precision analysis module is used for acquiring mileage and speed information from the satellite signal simulator and the intelligent GNSS code table respectively and calculating the precision of the intelligent GNSS code table. The invention has the advantages that the invention can repeatedly test and analyze by adopting various setting conditions, thereby further improving the accuracy and the credibility of the calibration.

Description

A kind of precision calibration system and calibration method

technical field

The invention relates to the technical field of satellite navigation, in particular to an accuracy calibration system and a calibration method.

Background technique

Cycling is currently a popular sport for people to explore nature and challenge themselves. Recording one's own movement track and sharing it with friends is also something that cycling enthusiasts are passionate about.

The athlete's riding position is usually acquired through a GNSS (Global Navigation Satellite System, Global Navigation Satellite System) positioning device (GNSS computer) attached to the mobile phone, and continuous acquisition can form a riding track. The GNSS code table uses the global satellite positioning system to receive satellite signals in space, and then performs calculations to obtain the data of speed, mileage, time, and altitude; at the same time, the data of cadence, heart rate, and power are obtained by connecting external sensors; finally A new type of measuring instrument that provides intuitive and rich riding data through comprehensive calculations.

GNSS currently occupying a relatively mainstream position includes: GPS (Global Positioning System, Global Positioning System) developed by the United States, GLONASS (GLOBAL NAVIGATION SATELLITE SYSTEM, Global Satellite Navigation System) developed by Russia, Beidou Navigation System developed by China and Galileo satellite developed by the European Union Navigation system (Galileo Satellite Navigation System).

Nowadays, GNSS stopwatches are very popular. Their advantages are that they can record track and cycling data, connect to social media, and be able to meet various needs such as navigation and fitness training. But about the speed of stopwatch, the accuracy of distance directly affects the best effect for people who pursue health day by day. At present, most of the tests for smart GNSS code tables are often carried out through mutual evaluation with different terminals, and quantitative evaluation cannot be prepared. The special test needs to be carried out on a high-precision mobile test vehicle, and real-time data records are used for comparison and analysis. For a high-precision test vehicle, a high-precision standard device and refitting on the test vehicle are required to meet the test requirements.

Contents of the invention

The purpose of the present invention is to provide a precision calibration system and a corresponding calibration method. The system/method can solve the defects that cannot be quantitatively evaluated caused by the mutual evaluation between different terminals, and can also solve the problems caused by the use of high-precision test vehicles. The problem of high cost of transformation and use in the future.

Based on the working principle of the intelligent GNSS code table, the present invention proposes a scene-based test method based on a satellite signal simulator, and builds a high-precision test platform by establishing a model test scene such as a sinusoidal motion trajectory model and a circular motion to form a specific test plan. Detect and calibrate the speed and mileage accuracy of the smart GNSS computer in a simulated environment.

First of all, the present invention proposes an accuracy calibration system for performing accuracy calibration on smart GNSS code tables in a simulated environment, including:

Satellite signal simulator, which simulates the navigation data of the satellite navigation system and provides corresponding radio frequency signals;

A reference frequency standard, providing a time-base reference signal to the satellite signal simulator;

The test scene module provides preset motion trajectory and limited condition selection;

The navigation signal control module controls the output of the satellite signal simulator, and controls the calling of the test scene module;

The accuracy analysis module obtains mileage and speed information from the satellite signal simulator and the intelligent GNSS code table respectively, and calculates the accuracy of the intelligent GNSS code table.

In the above-mentioned precision calibration system, wherein the controlling the output of the satellite signal simulator includes at least: selecting a simulated satellite system and selecting a radio frequency point.

In the above-mentioned precision calibration system, wherein, the limiting conditions of the test scene module include at least: an atmospheric delay model, a tropospheric delay model, an intelligent GNSS code table motion model, and a scene motion track.

The above-mentioned precision calibration system, wherein, in the precision analysis module, precision calibration is performed according to mileage error, speed error, speed precision and maximum speed.

The above-mentioned precision calibration system, wherein, when the update rate of the speed error, speed accuracy and maximum speed is greater than 1 Hz, a quadratic term or a spline fitting interpolation algorithm is used for compensation.

Secondly, the present invention also provides a kind of precision calibration method, is used for carrying out precision calibration to intelligent GNSS code table under simulation environment, comprises the following steps:

S1. Select a motion track scene;

S2, run the navigation signal control software, and collect the data of the intelligent GNSS code table;

S3, run the accuracy analysis software, and calibrate the accuracy of the smart GNSS code table;

S4. Repeat S1-S3 until the predetermined number of times is reached.

The above-mentioned accuracy calibration method, wherein, before step S1, further includes: preheating a satellite signal simulator that provides simulated navigation data.

The above-mentioned precision calibration method, in step S2, includes:

Controlling a satellite signal simulator to output at least: the frequency code, data, power and radio frequency point of the simulated satellite system;

The atmospheric delay model, the tropospheric delay model, the intelligent GNSS code table motion model and the scene motion trajectory in the test scene module are defined.

In the above-mentioned accuracy calibration method, in step S3, the accuracy calibration is performed according to the mileage error, speed error, speed accuracy and maximum speed; when the update rate of the speed error, speed accuracy and maximum speed is greater than 1Hz, the quadratic term is used Or spline fitting interpolation algorithm for compensation.

Based on the same inventive concept, the present invention also proposes a readable and writable storage medium on which an executable program is stored, and when the executable program is invoked, the above precision calibration method is implemented.

Compared with the prior art, the technical solution of the present invention provides the data of the satellite system through a satellite signal simulator, so that the calibration does not need to be carried out in the actual satellite system, which improves the convenience and reliability of the calibration; secondly, the present invention The technical solution unifies the test conditions such as path and climate during calibration by setting standard test scene modules, and realizes the repeatability of calibration, and the calibration of multiple code tables can be realized based on the same standard, which improves the reliability of calibration; the present invention The technical solution also realizes data collection and calculation through analysis and control software, which can be tested and analyzed repeatedly with various setting conditions, further improving the accuracy and reliability of calibration.

Description of drawings

Those skilled in the art know that the following drawings only illustrate some embodiments of the present invention, and those skilled in the art can also obtain other embodiments of the same nature according to these drawings (accompanying drawings) .

Fig. 1 is a block diagram of an embodiment of the calibration system in the present invention;

Fig. 2 is the functional block diagram of navigation signal control module in the present invention;

Fig. 3 is the working schematic diagram of precision analysis module in the present invention;

Fig. 4 is a schematic flowchart of the calibration method in the present invention.

Detailed ways

In order to make the purpose and features of the present invention more comprehensible, the specific implementation manners of the present invention will be further described below in conjunction with the accompanying drawings. However, the present invention can be implemented in different forms and should not be limited to the described embodiments. Moreover, in the case of no conflict, the embodiments in the present application and the features in the embodiments are allowed to be combined or replaced with each other. The advantages and features of the present invention will become clearer in conjunction with the following descriptions.

It should be noted that all the drawings are in very simplified form and use inaccurate scales, and are only used to facilitate and clearly assist the purpose of illustrating the embodiments of the present invention.

It should also be stated that the purpose of numbering the steps in the present invention is to facilitate reference, not to limit the sequence. For individual steps that need to be emphasized in order, special instructions will be given in special text in the text.

The core idea of the concept of the present invention is to propose a method based on satellite signal simulator and scene testing according to the principle of satellite navigation. That is, several standard scenes or customized special scenes are reserved to simulate the running track (including speed) of the smart GNSS computer, and combined with speed and mileage analysis software, the speed accuracy and mileage accuracy are calculated respectively. The test method is simple and feasible, and the test results are stable and reliable, which can provide a reliable technical basis for the calibration of the speed and mileage accuracy of the smart GNSS computer.

Please refer to Figure 1, this embodiment proposes a system for precision calibration of smart GNSS code tables in a simulated environment, mainly including a satellite signal simulator 1, a reference frequency standard 2, a navigation signal control module 3, and a test scene Module 4 and Precision Analysis Module 5.

The satellite signal simulator 1 is used to simulate the navigation data of the satellite navigation system and provide corresponding radio frequency signals. As mentioned in the background technology, there are many kinds of global navigation satellite positioning systems (GNSS), and in my country, the GPS system of the United States and the Beidou system of China are used more. Among them, the GPS system has 24 navigation satellites around the world, and the Beidou system has more than 30 satellites around the world. In people's actual life, positioning equipment can often receive data from the above two satellite systems at the same time. In the satellite signal simulator 1 of the present invention, the option of multi-satellite and multi-system is also set, and the user can choose which positioning system to use and simulate receiving signals of several satellites. At the same time, satellite signal simulator 1 also provides commonly used satellite communication frequency points for users to choose.

The reference frequency marker 2 is used to provide a time-base reference signal to the satellite signal simulator 1 . Time is closely related to frequency and navigation and positioning technology. For satellite navigation and positioning systems, the basis of navigation is positioning, the basis of positioning is ranging, the basis of ranging is to measure the delay of radio wave transmission, and the basis of measuring delay is a unified time-frequency reference. Only positioning data obtained under the same time base standard is based on credibility.

The test scene module 4 provides preset motion trajectory and limited condition selection. The preset motion trajectory includes not only the path of motion, but also the setting of its speed (acceleration) during motion. Preferably, the preset motion trajectory may include: uniform linear motion trajectory, sinusoidal motion trajectory and circular motion trajectory. Further, the track of the actual real route can also be saved in the test scene module 4 . However, the true route needs to be calibrated for its true value. When calibrating the true value, a high-precision integrated navigation receiver can be used, but its accuracy needs to be an order of magnitude higher than that of the smart GNSS code table.

As shown in FIG. 2 , the navigation signal control module 3 controls the output of the satellite signal simulator 1 and controls the calling of the test scene module 4 . Said controlling the output of the satellite signal simulator 1 at least includes: selecting a simulated satellite system and selecting a radio frequency point. Further, selecting the simulated satellite system includes selecting and enabling the visible satellite spreading code and the navigation data code, and selecting the signal power of the visible satellite. If the receiving sensitivity of the intelligent GNSS code meter is low, the satellite signal simulator 1 can be further set to improve the output signal power.

As shown in Figure 3, the accuracy analysis module 5 obtains mileage and speed information from the satellite signal simulator 1 and the intelligent GNSS code table 6 respectively, and calculates the accuracy of the intelligent GNSS code table 6 with the satellite signal simulator 1 as a standard value. Specifically, the accuracy analysis module 5 performs accuracy calibration according to the mileage error, speed error, speed accuracy and maximum speed. Wherein, when the update rate of the speed error, speed accuracy, and maximum speed is greater than 1 Hz, the corresponding update rate of the satellite signal simulator 1 needs to be configured, such as the satellite signal simulator 1 does not support a high-speed update rate (the update rate is greater than 1 Hz) , the precision analysis module 5 can use a quadratic term or a spline fitting interpolation algorithm for compensation.

The above-mentioned precision calibration system adopts a unified, stable and repeatable analog satellite navigation system and a standard reference time base, which provides a standard reference for the speed measurement and distance measurement (recording track) of the smart GNSS code table, and integrates all smart GNSS codes The data test of the meter is placed on the same scale, which solves the defect in the prior art that the mutual evaluation of different terminals can only qualitatively but not quantitatively detect the accuracy of the smart GNSS code meter. In the test scene module provided by the above-mentioned precision calibration system, a variety of preset motion trajectories are simulated through software, and the motion trajectories include the path of motion and the speed information of motion, which solves the high cost caused by the use of mobile test vehicles. , low efficiency, poor repeatability and other defects. In summary, the above-mentioned accuracy calibration system is simple, feasible, highly portable, and the test results are stable and reliable, which provides a reliable technical basis for the accuracy calibration of the speed and mileage of the smart GNSS computer.

As shown in FIG. 4 , based on the above-mentioned precision calibration system, the present invention also provides a precision calibration method for precision calibration of an intelligent GNSS code meter in a simulated environment. Specifically include the following steps:

S0. Preheat the satellite signal simulator, preferably more than 30 minutes;

S1. Select a motion track scene;

S2, run the navigation signal control software, and collect the data of the intelligent GNSS code table;

S3, run the accuracy analysis software, and calibrate the accuracy of the smart GNSS code table;

S4. Repeat S1-S3 until the predetermined number of times is reached.

In step S0, it is also necessary to set the satellite signal simulator as multi-satellite multi-system, and set corresponding satellite signal frequency points.

In step S1, the motion track scene includes:

a) Selection of atmospheric model and tropospheric delay model.

b) Edit motion track. Specifically, the motion trajectory includes a uniform linear motion trajectory, a sinusoidal motion trajectory, a circular motion trajectory, and a velocity value during motion. Further, it may also include a motion trajectory compiled according to the actual route.

c) defining the motion model of the intelligent GNSS code table (receiver), the motion model including static and dynamic models. When using the dynamic motion model, it is also necessary to initialize the static scene configuration to fully position (initial position) the smart GNSS code table.

In step S2, the above-mentioned motion trajectory scene is loaded by the navigation signal control software, and the visible satellite spreading code and navigation data code are opened, and the visible satellite signal power is set (generally set to -130dBm); if the intelligent GNSS code table The receiving sensitivity is low, which can further increase the output signal power of the visible satellite signal power.

In step S3, the accuracy analysis software acquires the mileage error, speed error, speed accuracy, and maximum speed. For speed analysis, UTC time or local time must be strictly aligned.

The above precision calibration method builds a high-precision test platform by establishing model test scenarios such as linear motion trajectory model, sinusoidal motion trajectory model, and circular motion, and forms a specific test plan, which can detect the speed of the smart GNSS stopwatch in a simulated environment and mileage accuracy, the method is simple and reliable, with high repeatability and high reliability of the obtained data.

Finally, the present invention also provides a readable and writable storage medium, on which an executable program is stored, and when the executable program is called, the above precision calibration method can be realized. Those skilled in the art should know that the above methods and steps can be directly embodied in hardware (system on chip Soc), in a software module executed by a processor, or in a combination of both. A software module may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. In an alternative, the storage medium may be integrated into the processor, the processor and storage medium may reside in an ASIC, and the ASIC may reside in a user terminal. Similarly, in another alternative, the processor and the storage medium may reside in the user terminal as discrete components.

Obviously, those skilled in the art can make various changes and modifications to the invention without departing from the spirit and scope of the invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention also intends to include these modifications and variations.

Claims (9)

1. An accuracy calibration system for accuracy calibration of an intelligent GNSS code table in a simulated environment, comprising:

the satellite signal simulator simulates navigation data of a satellite navigation system and provides corresponding radio frequency signals;

a reference frequency scale providing a time-based reference signal to the satellite signal simulator;

the test scene module provides a preset motion trail and limiting condition selection;

the navigation signal control module controls the output of the satellite signal simulator and controls the calling of the test scene module;

the precision analysis module is used for acquiring mileage and speed information from the satellite signal simulator and the intelligent GNSS code table respectively and calculating the precision of the intelligent GNSS code table; the precision analysis module carries out precision calibration according to the mileage error, the speed precision and the maximum speed; when the update rate of the speed error, the speed precision and the maximum speed is greater than 1Hz, the update rate of the corresponding satellite signal simulator is required to be configured.

2. The precision calibration system of claim 1, wherein the controlling the output of the satellite signal simulator comprises at least: the simulated satellite system is selected and the radio frequency point is selected.

3. The precision calibration system of claim 1, wherein the defining conditions of the test scene module include at least: an atmospheric delay model, a tropospheric delay model, an intelligent GNSS code table motion model and a scene motion trail.

4. The accuracy calibration system of claim 1, wherein when the update rate of the speed error, speed accuracy, and maximum speed is greater than 1Hz, a quadratic term or spline fitting interpolation algorithm is employed to compensate.

5. A precision calibration method, characterized in that the precision calibration system according to any one of claims 1-4 is used for performing precision calibration on an intelligent GNSS code table in a simulation environment, comprising the following steps:

s1, selecting a motion trail scene;

s2, running navigation signal control software, and collecting data of an intelligent GNSS code table;

s3, running accuracy analysis software to calibrate the accuracy of the intelligent GNSS code table;

s4, repeating the steps S1 to S3 until the preset times are reached.

6. The method of calibrating accuracy according to claim 5, further comprising, prior to step S1: a satellite signal simulator providing simulated navigation data is preheated.

7. The method of calibrating accuracy according to claim 5, wherein in step S2, comprising:

controlling at least one satellite signal simulator to output: the frequency code, data, power and radio frequency point of the simulated satellite system;

and defining an atmosphere delay model, a troposphere delay model, an intelligent GNSS code table motion model and a scene motion trail in the test scene module.

8. The method according to claim 5, wherein in step S3, accuracy calibration is performed based on mileage error, speed accuracy, and maximum speed; and when the update rate of the speed error, the speed precision and the maximum speed is greater than 1Hz, adopting a quadratic term or spline fitting interpolation algorithm to compensate.

9. A readable and writable storage medium, characterized in that an executable program is stored thereon, which when called implements the accuracy calibration method according to any one of claims 5-8.

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