Device and method for testing dynamic positioning precision of GNSS (Global Navigation Satellite System) receiver

Abstract

According to the device and the method for testing the dynamic positioning precision of the GNSS receiver provided by the invention, the dynamic positioning precision of the GNSS receiver is tested by adopting a grating coding bar arranged along a test track, a photoelectric or magnetic initial position detection mark, a coding bar detector on a test carrier and means such as clock synchronization with the tested GNSS; the structure is simple; the output truth value precision can be controlled by controlling the size of the grating, and the grating spacing can be selected according to actual needs. In practical application, a 0.5 mm grating or magnetic grid is adopted, the output precision of the real position is 0.5 mm, and the requirement for evaluating the positioning precision of the GNSS receiver can be completely met.

Description

Technical Field

[0001] The invention relates to the field of testing positioning, and in particular provides a device and method for testing the dynamic positioning accuracy of a GNSS receiver. Background Art

[0002] GNSS receivers are instruments used to receive global navigation satellite system signals and determine the ground space position.

[0003] GNSS receivers can receive signals from multiple global navigation satellite systems (such as GPS, GLONASS, Galileo and BeiDou systems) and determine the user's position, speed and time by processing these signals. GNSS receivers are widely used, including but not limited to navigation, positioning, timing and precision measurement.

[0004] GNSS receivers are classified by purpose:

[0005] Navigation receiver: mainly used for navigation of moving carriers, providing real-time position and speed information.

[0006] Geodetic receiver: used for precision geodetic and engineering surveying, providing high-precision positioning.

[0007] Timing receiver: uses the high-precision time standard provided by GNSS satellites for timing.

[0008] GNSS receivers are classified by carrier frequency:

[0009] Single-frequency receiver: only receives L1 carrier signal, suitable for short baseline precision positioning.

[0010] Dual-frequency receiver: can receive L1 and L2 carrier signals simultaneously, suitable for long-baseline precision positioning, and improves positioning accuracy by eliminating the influence of ionospheric delay.

[0011] GNSS receivers are now widely used in various fields, such as:

[0012] 1. Slope displacement monitoring: In the field of geological disaster prevention and infrastructure safety, GNSS displacement monitoring stations receive satellite signals through high-precision GNSS receivers to achieve high-precision measurement and monitoring of slope displacement, providing an accurate data basis for slope stability and safety assessment.

[0013] 2. Precision measurement: Geodetic receivers are used for precision geodetic and engineering surveying, providing high-precision positioning services.

[0014] 3. Navigation and positioning: In the fields of vehicles, aviation, navigation, etc., GNSS receivers provide real-time position and speed information to support navigation and positioning needs.

[0015] With the advancement of technology, GNSS receivers are developing towards higher accuracy, smaller size and lower cost. For example, modern GNSS receivers can be integrated into portable devices such as smartphones, providing centimeter-level or even millimeter-level positioning accuracy. In addition, multi-system compatible GNSS receivers can simultaneously receive signals from multiple satellite navigation systems, improving the reliability and accuracy of positioning.

[0016] However, this method and device still have some potential disadvantages:

[0017] For example, patent CN103399326A introduces a GNSS dynamic measurement accuracy inspection system and method. The invention effectively combines the characteristics of total station and GNSS, uses GNSS equipment to provide a high-precision time reference for the total station, and synchronously observes the coaxial 360-degree prism and GNSS mobile station. Through coordinate conversion and epoch matching, the total station measurement results with an order of magnitude higher accuracy than GNSS dynamic measurement are used as a reference, and the accuracy of GNSS dynamic measurement can be accurately calculated, which fills the gap in related fields and provides a set of effective technical solutions for GNSS for scientific research, instrument calibration, and production practice. However, the solution provided by the patent requires an automatic tracking total station, as well as multiple equipment such as optical prisms. The system of this solution is complex and the measurement speed is not high.

[0018] Another example is the verification method of the dynamic positioning accuracy of a mobile carrier positioning device introduced in CN202310234657.3. This method transfers the actual measurement point of the positioning device to be measured to the wheel of the mobile carrier through coordinate correction, and then uses lime markings to record the specific position of the actual measurement point. At the same time, a high-speed camera is used to determine the exact time of the actual measurement point at the position, and the measured coordinates at that moment are determined by interpolation. Finally, the relative distance of the markings is calculated twice according to the positioning data, and compared with the actual distance, thereby realizing the verification of positioning accuracy. The verification method of the dynamic positioning accuracy of the mobile carrier positioning device provided by the present invention is simple and easy to operate, suitable for actual engineering site positioning accuracy testing, and can effectively meet the needs of intelligent monitoring of engineering machinery. However, this scheme adopts the photographing method, uses ground markings, and interpolation is used between markings. Its measurement accuracy is not high, and post-processing is required, and it is difficult to obtain real-time results.

[0019] And because the position of moving objects is constantly changing, the dynamic positioning accuracy of GNSS receivers is difficult to test. The existing technology has many drawbacks that need to be solved urgently. Summary of the invention

[0020] In order to solve one or several problems in the prior art, the present invention takes into account the above-mentioned problems in the prior art and proposes a novel device and method for testing the dynamic positioning accuracy of a GNSS receiver, which can accurately test the dynamic positioning accuracy of a GNSS receiver without requiring overly complicated subsequent processing operations.

[0021] The present invention arranges position coding strips in the test space and uses GNSS for time synchronization to obtain the real and accurate position (true value) of the test vehicle at a fixed moment, and compares this position with the position output by the GNSS receiver at that moment to obtain the dynamic positioning accuracy of the GNSS receiver.

[0022] In order to achieve the above-mentioned object of the invention, the present invention proposes a novel device and method for testing the dynamic positioning accuracy of a GNSS receiver.

[0023] Specifically, it is a new type of device for testing the dynamic positioning accuracy of a GNSS receiver, including a test vehicle and a grid; the test vehicle includes a true value acquisition device and a GNSS receiver under test

[0024] A fixed, equally spaced grid is arranged on the running track of the test vehicle;

[0025] The true value acquisition device includes a grid detector. When the test vehicle is running, each grid causes the grid detector on the true value acquisition device to generate a pulse, and the total number of pulses n recorded by the test vehicle at a certain moment is recorded;

[0026] The test vehicle also includes a position truth table; when the test vehicle is running, at a certain moment, the truth value acquisition device searches the position truth table according to the pulse count value to obtain the truth value;

[0027] The clock synchronization device synchronizes the time of the true value acquisition device with the time of the GNSS receiver under test, and compares the positions output by the true value acquisition device and the GNSS receiver under test at the same time to obtain the position accuracy of the GNSS receiver under test.

[0028] The spacing d of the grid (grating encoding strips or magnetic grating encoding strips) determines the accuracy of the acquired true position, and the true value accuracy of the output can be controlled by controlling the size of the grid.

[0029] The grid spacing can be selected according to actual needs. In practical applications, 0.5mm grating or magnetic grating is used, and the true position output accuracy is ±0.5mm, which can fully meet the requirements for evaluating the positioning accuracy of GNSS receivers.

[0030] When the test vehicle is running, each grid will cause the sensor on the true value acquisition device to generate a pulse, starting from the starting position, and record the total number of pulses n recorded by the test fixture at a certain moment. The count value 0 corresponds to the starting position. If the trajectory is a straight line, the count value 1 corresponds to the distance d*1 from the starting position along the trajectory backward. By analogy, the count value n corresponds to the distance d*n from the starting position along the trajectory backward.

[0031] If the trajectory is a known curve, the position corresponding to each count value n can also be calculated based on the curve equation. The starting point position can be measured by geodetic methods or long-term static RTK to obtain a very accurate position. The running trajectory of the test vehicle is fixed. After starting from the starting point, the position corresponding to each count value n can be calculated by mathematical methods or measured by static RTK, and finally a position truth table is formed.

[0032] If the coordinate trajectory is an unknown curve, it is necessary to measure the position corresponding to each grid count value; obtain the corresponding coordinates of each grid count value, and finally form a position truth table.

[0033] When the test vehicle is running, at a certain moment, the true value can be obtained by looking up the table according to the pulse count value n. Here, the device that outputs the true value is called a truth valuer.

[0034] The time of the truth valuer and the GNSS receiver under test is synchronized. Because the test vehicle is moving, it is meaningful to perform accuracy detection only when the true value output at the same time and the position output by the GNSS receiver under test are output. The truth valuer uses the PPS pulse per second output of the GNSS under test as the clock synchronization source, maintains the detection clock of the truth valuer itself, and synchronizes the position output of the truth valuer and the GNSS receiver under test.

[0035] The present invention also discloses a method for testing the dynamic positioning accuracy of a GNSS receiver. The method is implemented based on the device for testing the dynamic positioning accuracy of a GNSS receiver, and comprises:

[0036] S1. Lay out the test track grid along the test track and set the starting position signal flag. When the test vehicle passes by, the starting position signal is detected to clear the grid counter;

[0037] S2. Accurately measure the coordinate trajectory at the starting position signal mark,

[0038] If the coordinate trajectory is a straight line or a known curve, the coordinates of other grid count values ​​are directly calculated from the position of the start signal mark according to the grid spacing d;

[0039] If the coordinate trajectory is an unknown curve, it is necessary to measure the position corresponding to each grid count value; obtain the corresponding coordinates of each grid count value;

[0040] A truth table corresponding to the count value and the position is formed, and the truth table is stored in a memory of the truth value device;

[0041] S3. The truth valuer obtains the second pulse and MEMA, RMC statements from the GNSS receiver under test, and uses them to synchronize its own timer. After the clock is synchronized, the truth valuer obtains the grid count n of the mobile carrier at the required time interval, and then queries the truth table based on the grid count n to obtain the position truth value and output it.

[0042] S4. Compare the positions output by the truth valuer and the GNSS receiver under test at the same time to obtain the position accuracy of the GNSS receiver under test.

[0043] And the starting signal is an optical signal or a magnetic signal;

[0044] The coordinates are longitude and latitude;

[0045] The truth valuer is arranged at equal time intervals of 0.01-0.1 seconds.

[0046] Compared with the prior art, the present invention also has the advantages of:

[0047] 1. The present invention uses a coding strip photoelectric or magnetic starting position detection mark arranged along the test track, a coding strip detector on the test vehicle, and clock synchronization with the GNSS under test to test the dynamic positioning accuracy of the GNSS receiver, which is convenient and fast with a simple structure.

[0048] 2. The present invention can control the true value accuracy of the output by controlling the size of the grid, and the grid spacing can be selected according to actual needs. In practical applications, a 0.5mm grating or magnetic grid is used, and the true position output accuracy is ±0.5mm, which can fully meet the requirements for evaluating the positioning accuracy of the GNSS receiver. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 Schematic diagram of an apparatus according to an embodiment of the present invention. DETAILED DESCRIPTION

[0050] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0051] The following is in conjunction with the instruction manual Figure 1 The present invention is further described in detail with reference to the accompanying drawings and specific embodiments.

[0052] A fixed equidistant grid (optical grating code strips or magnetic grating code strips) is arranged on the running track of the test vehicle. The spacing d of the grid determines the accuracy of the acquired real position. The true value accuracy of the output can be controlled by controlling the size of the grid.

[0053] The grid spacing can be selected according to actual needs. In practice, a 0.5mm grating or magnetic grating is used, and the true position output accuracy is ±0.5mm, which can fully meet the requirements for evaluating the positioning accuracy of the GNSS receiver.

[0054] When the vehicle is running, each grid will cause the sensor on the true value acquisition device to generate a pulse, starting from the starting position, and record the total number of pulses n recorded by the test fixture at a certain moment. The count value 0 corresponds to the starting position. If the trajectory is a straight line, the count value 1 corresponds to the distance d*1 from the starting position along the trajectory backwards. By analogy, the count value n corresponds to the distance d*n from the starting position along the trajectory backwards.

[0055] If the trajectory is a known curve, the position corresponding to each count value n can also be calculated based on the curve equation. The starting point position can be measured by geodetic methods or long-term static RTK to obtain a very accurate position. The running trajectory of the test fixture is fixed. After starting from the starting point, the position corresponding to each count value n can be calculated by mathematical methods or measured by static RTK, and finally a position truth table is formed.

[0056] When the test vehicle is running, at a certain moment, the true value can be obtained by looking up the table according to the pulse count value n. Here, the device that outputs the true value is called a truth valuer. The time of the truth valuer and the GNSS receiver under test is synchronized. Because the test vehicle is moving, it is meaningful to perform accuracy detection only when the true value output at the same time and the position output by the GNSS receiver under test are used. The truth valuer uses the PPS second pulse output by the GNSS under test as the clock synchronization source, maintains the detection clock of the truth valuer itself, and synchronizes the position output of the truth valuer and the GNSS receiver under test.

[0057] The specific steps of a method for testing the dynamic positioning accuracy of a GNSS receiver are:

[0058] Step 1. Lay out the test track grid along the test track and set the starting position signal mark. The starting signal can be an optical signal or a magnetic signal. When the test vehicle passes by, this signal is detected and the grid counter is cleared.

[0059] Step 2. Accurately measure the coordinates (latitude and longitude) of the starting signal mark. If the trajectory is a straight line or a known curve, the coordinates (latitude and longitude) of other grid count values ​​can be directly calculated from the position of the starting point according to the grid spacing d. If it is an unknown curve, it is necessary to measure the position corresponding to each grid count value. In this way, the corresponding coordinates (latitude and longitude) of each grid count value are obtained. The corresponding table of count values ​​and positions finally formed is called a truth table here, and these data are stored in the memory of the truth valuer.

[0060] Step 3. The truth valuer obtains the second pulse and MEMA, RMC statements from the GNSS receiver under test and uses them to synchronize its own timer. After the clock is synchronized, the truth valuer can obtain the grid count n of the mobile carrier at time intervals such as 0.10-0.1 seconds as needed, and then query the truth table based on the grid count n, obtain the position truth value and output it, where the time interval can be 0.1 second and 0.01 second.

[0061] Step 4. Compare the positions output by the truth valuer and the GNSS receiver under test at the same time to obtain the position accuracy of the GNSS receiver under test.

[0062] The above are preferred embodiments of the present invention. The protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should be regarded as the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the attached claims.

[0063] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media provided by the present invention and used in the embodiments can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. As an illustration and not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (SSRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).

[0064] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, device, article or method including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, device, article or method. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the presence of other identical elements in the process, device, article or method including the element.

Claims

1. A device for testing the dynamic positioning accuracy of a GNSS receiver, comprising a test vehicle and a grid; the test vehicle comprises a true value acquisition device and a GNSS receiver under test; A fixed equidistant grid is arranged on the running track of the test vehicle; The true value acquisition device includes a grid detector. When the test vehicle is running, each grid causes the grid detector on the true value acquisition device to generate a pulse, and the total number of pulses n recorded by the test vehicle at a certain moment is recorded; The test vehicle also includes a position truth table; When the test vehicle is running, at the certain moment, the truth value acquisition device queries the position truth table according to the total number of pulses n to obtain the truth value; The true value acquisition device also includes a clock synchronization device, which synchronizes the time of the true value acquisition device with the time of the GNSS receiver under test, and compares the positions output by the true value acquisition device and the GNSS receiver under test at the same time to obtain the position accuracy of the GNSS receiver under test.

2. The device for testing the dynamic positioning accuracy of a GNSS receiver according to claim 1, characterized in that: The grid is a grating coding strip or a magnetic grating coding strip; the grid detector is a coding strip detector.

3. The device for testing the dynamic positioning accuracy of a GNSS receiver according to claim 1, characterized in that: The spacing of the grid is fixed, and the true value accuracy of the output is controlled by controlling the size of the grid.

4. The device for testing the dynamic positioning accuracy of a GNSS receiver according to claim 1, characterized in that: The running trajectory of the test vehicle is a straight line. When the count value is 0, it corresponds to the starting position, and when the count value is 1, it corresponds to the distance d*1 backward along the trajectory from the starting position. And so on. When the count value is the total number of pulses n, it corresponds to the distance d*n backward along the trajectory from the starting position, finally forming the position truth table.

5. The device for testing the dynamic positioning accuracy of a GNSS receiver according to claim 1, characterized in that: The running trajectory of the test vehicle is a known curve. The starting point position is obtained by geodetic measurement or long-term static RTK measurement. The running trajectory of the test vehicle is fixed. After the starting point, the position corresponding to each count value is calculated by mathematical methods or measured by static RTK. When the final count value is the total number of pulses n, the position truth table is finally formed.

6. The device for testing the dynamic positioning accuracy of a GNSS receiver according to claim 2, characterized in that: The grating or magnetic grating adopts a 0.5mm grating or magnetic grating, and the actual position output accuracy is ±0.5mm.

7. The device for testing the dynamic positioning accuracy of a GNSS receiver according to claim 1, characterized in that: The truth value acquisition device is a truth valuer.

8. The device for testing the dynamic positioning accuracy of a GNSS receiver according to claim 7, characterized in that: The truth valuer uses the PPS pulse per second output by the GNSS receiver under test as a clock synchronization source, maintains the detection clock of the truth valuer itself, and synchronizes the position output of the truth valuer with that of the GNSS receiver under test.

9. A method for testing the kinematic positioning accuracy of a GNSS receiver, the method being implemented based on the device for testing the kinematic positioning accuracy of a GNSS receiver according to any one of claims 1 to 8, characterized in that: S1. Lay out the test track grid along the test track and set the starting position signal flag. When the test vehicle passes by, the starting position signal is detected to clear the grid counter; S2. Accurately measure the coordinate trajectory at the starting position signal mark, If the coordinate trajectory is a straight line or a known curve, the coordinates of other grid count values ​​are directly calculated from the position of the start signal mark according to the grid spacing d; If the coordinate trajectory is an unknown curve, it is necessary to measure the position corresponding to each grid count value; obtain the corresponding coordinates of each grid count value; A position truth table corresponding to the count value and the position is formed, and the data of the position truth table is stored in a memory of the truth value device; S3. The truth value acquisition device obtains the second pulse and MEMA, RMC statements from the GNSS receiver under test, and uses it to synchronize its own timer. After the clock is synchronized, the truth value acquisition device obtains the grid count n of the mobile carrier at the required time interval, and then queries the truth table according to the grid count n to obtain the true value of the position and output it; S4. Compare the positions output by the true value acquisition device and the GNSS receiver under test at the same time to obtain the position accuracy of the GNSS receiver under test.

10. The method for testing the dynamic positioning accuracy of a GNSS receiver according to claim 9, characterized in that: The starting position signal is an optical signal or a magnetic signal; The coordinates are longitude and latitude; The true value acquisition device is arranged at equal time intervals of 0.01-0.1 seconds.

Images