KR102472407B1 - Dynamic reliability decision method and apparatus for gnss based dead reckoning system - Google Patents

Abstract

The present invention relates to a method and apparatus for determining dynamic reliability of a dead reckoning system based on GNS, wherein a controller checks whether Global Navigation Satellite System (GNSS) information is received, if the GNS information is not received, determining, by the control unit, that the shaded period has entered and measuring the duration of the shaded period; based on the measured duration of the shaded period, the control unit determines reliability of the GNS information resetting the reliability criterion, determining whether or not the GNS information satisfies the reliability criterion according to the reset reliability criterion, and if the GNS information satisfies the reset reliability criterion, the and correcting, by the control unit, location information and heading information using the GNS information.

Description

Method and apparatus for determining dynamic reliability of dead reckoning system based on GNS

The present invention relates to a method and apparatus for determining dynamic reliability of a dead reckoning system based on GNS, and more particularly, to a GNS that dynamically determines reliability criteria for received information of a GNSS signal according to driving conditions in shadow sections. It relates to a method and apparatus for determining the dynamic reliability of a dead reckoning system.

In general, in a navigation system that guides a moving object to a destination by providing location information and route information to a moving object such as an aircraft, ship, or vehicle, it is important to first determine an accurate location of the moving object.

Accordingly, most current navigation systems basically use a Global Navigation Satellite System (GNSS) that accurately tracks the location of a target on the ground using a satellite network.

The GNSS uses satellites such as the US Global Positioning System (GPS), Russia's GLONASS (Global Navigation Satellite System), Europe's GALILEO (European Satellite Navigation System), and China's Beidou (北斗, Compass). It is a name that combines various positioning systems.

Since the GNSS determines location using satellites, it can easily acquire location, speed, and time information regardless of time and space, and is classified as a relatively stable system compared to other navigation systems. However, errors in location information may occur due to the influence of the ionosphere, multipath, and receiver noise, or the location may not be determined due to obstacles preventing satellite signals from being received.

Therefore, current navigation systems are often used in combination with other systems rather than using only GNSS alone.

As a system used in combination with GNSS, there is dead reckoning (DR) using sensing values of various sensors. The dead reckoning (DR) is a general technology used for positioning and navigation. Acquisition of location and route data of a moving object using an inertial sensor when entering a shadow area where GNSS signals cannot be received, such as a tunnel or underground parking lot do.

However, in this dead reckoning (DR), the drift errors of the sensors accumulate infinitely as the application time increases, and even when entering the shaded area, the dead reckoning (DR) continues until reliable GNSS data (or GNSS reception information) is received. ) is applied, there is a problem in that errors (e.g., location information and heading errors) continue to accumulate. Therefore, in the GNSS-based dead reckoning (DR) system, a method for quickly correcting the position information and heading error of a moving object by using reliable GNSS data (or GNSS reception information) according to the driving situation in the shadow section is required. have.

The background art of the present invention is disclosed in Republic of Korea Patent Registration No. 10-1535873 (registered on July 6, 2015, vehicle position estimation system and method combining satellite positioning system and dead reckoning).

According to one aspect of the present invention, the present invention was created to solve the above problems, and is a GNS-based system that dynamically determines reliability criteria for received information of GNSS signals according to driving conditions in shadow sections. An object of the present invention is to provide a method and apparatus for determining dynamic reliability of a dead reckoning system.

A method for determining dynamic reliability of a dead reckoning system based on GNS according to an aspect of the present invention includes: checking, by a controller, whether Global Navigation Satellite System (GNSS) information is received; If the GNS information is not received, the controller determines that a shadow section has entered and measures a duration of the shadow section; resetting, by the control unit, a criterion for determining reliability of the GNS information based on the measured duration of the shaded section; determining, by the controller, whether the GNS information satisfies the reliability criterion according to the reset reliability criterion; and correcting, by the control unit, location information and heading information using the GNS information if the GNS information satisfies the reset reliability criterion.

In the present invention, in the step of resetting the criterion for determining reliability of the GNS information, the duration of the shaded section is compared with a preset threshold, so that the duration of the shaded section is set to a preset threshold. If it is not smaller than the value, the controller changes a threshold criterion for determining the reliability of sensitivity information of the GNS information, and resets the criterion for determining the reliability of the GNS information.

In the present invention, if the duration of the shaded section is smaller than a preset threshold value, the control unit calculates the rate of change of the previous and current heading information using the GNS information, and uses the inertial sensor of the sensor unit to calculate the previous change rate. After calculating the change rate of the current heading information and the heading change rate calculated using the GNS information and the heading change rate calculated using the inertial sensor, based on the difference in the calculated heading information change rate, the change rate and setting a GNSS reliability determination flag to 1 if the difference in the change rate is less than or equal to a threshold value, and setting the GNSS reliability determination flag to 0 if the difference in rate of change is greater than the threshold value.

In the present invention, according to the set value of the GNSS reliability determination flag, the control unit, if the GNSS reliability determination flag is 0, even if the sensitivity information of the GNS information is reliable, the incorrect GNSS location Since it means that information can be output, it is characterized by resetting the reliability criterion of GNSS information.

An apparatus for determining dynamic reliability of a dead reckoning system based on GNS according to another aspect of the present invention includes a GNS receiver for receiving Global Navigation Satellite System (GNSS) information; a timer unit for measuring a duration of a shadow section when entering a shadow section in which the GNS information is not received; Resetting the reliability criterion of the GNS information based on the duration of the measured shaded section, and determining whether the GNS information satisfies the reliability criterion according to the reset reliability criterion, and a control unit for correcting location information and heading information using the GNS information when the GNS information satisfies the reset reliability criterion.

In the present invention, in order to reset the criterion for determining reliability of the GNS information, the control unit compares the duration of the shaded section with a preset threshold value, and the duration of the shaded section is If it is not smaller than the preset threshold, the threshold criterion for determining the reliability of the sensitivity information of the GNS information is changed, and the reliability criterion of the GNS information is reset.

In the present invention, if the duration of the shaded section (Duration) is less than a preset threshold value, the control unit calculates the change rate of the previous and current heading information using the GNS information, and uses the inertial sensor of the sensor unit to calculate the rate of change of the heading information. After calculating the change rate of the previous and current heading information, the heading change rate calculated using the GNS information and the heading change rate calculated using the inertial sensor are compared, and based on the difference in the change rate of the calculated heading information, A GNSS reliability determination flag is set to 1 when the difference in change rate is less than a threshold value, and a GNSS reliability determination flag is set to 0 when the difference in change rate is greater than the threshold value.

In the present invention, according to the setting value of the GNSS reliability determination flag, the control unit, if the GNSS reliability determination flag is 0, even if the sensitivity information of the GNS information is reliable, an incorrect GNSS location Since it means that information can be output, it is characterized by resetting the reliability criterion of GNSS information.

According to an aspect of the present invention, the present invention enables a GNSS-based dead reckoning system to dynamically determine reliability criteria for received information of a GNSS signal according to the driving situation of a shadow section, so that GNSS data (or GNSS reception information) can be quickly used to quickly correct the location information and heading error of a moving object.

1 is an exemplary diagram showing a schematic configuration of an apparatus for determining dynamic reliability of a GNS-based dead reckoning system according to an embodiment of the present invention;
2 is a flowchart illustrating a method for determining dynamic reliability of a GNS-based dead reckoning system according to an embodiment of the present invention.
FIG. 3 is a flowchart for explaining a method of resetting the reliability criterion of GNSS reception information according to the period in the shadow section in FIG. 2; FIG.

Hereinafter, an embodiment of a method and apparatus for determining dynamic reliability of a GNS-based dead reckoning system according to the present invention will be described with reference to the accompanying drawings.

In this process, the thickness of lines or the size of components shown in the drawings may be exaggerated for clarity and convenience of explanation. In addition, terms to be described later are terms defined in consideration of functions in the present invention, which may vary according to the intention or custom of a user or operator. Therefore, definitions of these terms will have to be made based on the content throughout this specification.

1 is an exemplary diagram showing a schematic configuration of an apparatus for determining dynamic reliability of a GNS-based dead reckoning system according to an embodiment of the present invention.

As shown in FIG. 1, the apparatus for determining the dynamic reliability of a GNS-based dead reckoning system according to this embodiment includes a GNSS receiver 110, a sensor unit 120, a controller 130, a timer unit 140, and It includes a position correction unit 150.

The GNSS receiving unit 110 receives GNSS data (or GNSS reception information) from a satellite through a GNSS antenna (not shown).

In this embodiment, the GNSS data is GNSS raw measurement data, and the number of satellites used for GNSS positioning and pseudorange information can be obtained by analyzing the GNSS raw measurement data. Of course, the GNSS data includes the time when the GNSS raw measurement data was obtained.

The sensor unit 120 includes one or more sensors (or inertial sensors), and each of the one or more sensors measures the state of the vehicle in a preset manner to obtain sensor data.

At this time, at least one sensor (or inertial sensor) of the sensor unit 120 may be distributed in each part of the vehicle, and according to each function, the vehicle's steering angle, yaw rate, wheel pulse, acceleration, Measure angular velocity, etc. Here, the sensor data obtained from the at least one or more sensors (or inertial sensors) also includes time information for acquiring each sensor data.

The controller 130 calculates the current location of the vehicle using the received GNSS data or sensor data.

At this time, in this embodiment, the control unit 130 variably applies the reliability criterion of the GNSS reception information according to the situation (eg, when entering a shaded area, when entering a shaded area), that is, when the vehicle enters a shaded area, GNSS reception By variably adjusting the criterion for determining the reliability of information, it is possible to more quickly correct positional information and heading errors compared to the conventional method (that is, the conventional method in which the reliability criterion of GNSS received information is fixedly set).

The timer unit 140 measures the duration when the vehicle enters the shaded area. That is, the duration (Duration) in which the vehicle is in the shaded area is measured.

In this embodiment, the criterion for determining the reliability of GNSS received information is varied according to the duration of the vehicle being in the shaded section. For example, when the period in which the vehicle is in the shadow section is increased compared to a preset threshold value, the control unit 130 may change the reliability criterion of GNSS reception information to a low level.

As described above, when the reliability criterion of the GNSS reception information is changed to a low level, the GNSS reception information can quickly satisfy the reliability criterion, so that the GNSS reception As much as the time shortened when information quickly satisfies reliability), the control unit 130 can quickly correct positional information and heading error by quickly applying GNSS received information instead of dead reckoning using a sensor.

Under the control of the control unit 130, the position correction unit 150 corrects vehicle position information and heading error with errors accumulated by dead reckoning using GNSS received information that satisfies the reliability.

Meanwhile, in this embodiment, for convenience of description, the control unit 130, the timer unit 140, and the position correcting unit 150 are described as separate components, but in reality the control unit 130 is the timer Note that the functions of the unit 140 and the position correction unit 150 may be integrally performed. Therefore, in the following description of the present embodiment, it is assumed that the control unit 130 performs the functions of the timer unit 140 and the position correcting unit 150 integrally.

As already described above, GNSS reception information (or GNSS data) includes relatively accurate location information as there is almost no reception error due to multipath fading in the case of an open area without buildings (Open Sky), but it can be used in urban areas, tunnels, and underground parking lots. In the section, inaccurate location information is included due to various factors such as multipath fading, receiver noise, satellite reception failure, and atmospheric layer effects.

Accordingly, in this embodiment, considering the period in which the vehicle was in the shaded area (i.e., the driving situation in the shaded area), the reliability determination criterion is dynamically reset when the vehicle enters the shaded area, and the GNSS reception information is applied to calculate the position. By shortening the time, it is possible to quickly correct the position of the vehicle with accumulated errors by dead reckoning.

2 is a flowchart illustrating a method for determining the dynamic reliability of a GNS-based dead reckoning system according to an embodiment of the present invention, and FIG. It is a flowchart for explaining a method of resetting the judgment standard in more detail.

A method for determining dynamic reliability of a GNS-based dead reckoning system will be described below with reference to FIGS. 2 and 3 .

Referring first to FIG. 2, the controller 130 selects the GNSS receiver 110 to receive GNSS information (S101), and checks whether GNSS information is received through the GNSS receiver 110 (S102) .

As a result of the check (S102), if GNSS information is not received (No in S102), the control unit 130 determines that the vehicle has entered the shaded area and measures the duration (Duration) in the shaded area (S103 ).

The duration of the measured shaded area is used as basic information for resetting the reliability criterion of GNSS reception information (or GNSS data).

Meanwhile, as a result of the check (S102), if GNSS information is received (YES in S102), the controller 130 extracts sensitivity information of the GNSS received information (S104).

Here, the sensitivity information of the GNSS reception information is information obtained by parsing the NMEA (National Marine Electronics Association) protocol, and includes the number of satellites, the signal noise ratio of the satellite signal, and the horizontal/vertical/position accuracy degradation rate (Horizontal/Vertical/Position Dilution of Precision), horizontal position error (Equivalent horizontal position error), and the like, and are information that can be used to determine the reliability of GNSS reception information (GNSS data) according to the present embodiment.

In addition, the control unit 130 measures vehicle location information using at least one sensor (eg, an inertial sensor such as a gyro sensor or a vehicle speed sensor) of the sensor unit 120 (S105).

For reference, in the step of measuring the location information of the vehicle (S105), the control unit 130 corrects the offset and scale factor components of the gyro sensor and synchronizes the time with the vehicle speed sensor to determine the drift error and time synchronization delay over time. It is possible to increase the accuracy of vehicle positioning by reducing the error.

Next, the control unit 130 uses the duration information in the shadow section measured in step S103 and the sensitivity information of the GNSS reception information extracted in step S104 to determine the current driving situation in the shadow section (eg : The reliability criterion (that is, the reliability criterion of GNSS reception information) is reset in response to entering the shaded area or leaving the shaded area (S106).

In this embodiment, the reliability criterion of the GNSS reception information may be set higher or lower than the previous situation (typically, the reliability criterion is set to the lowest when entering the shaded area and can be set gradually higher thereafter), When the reliability criterion of the GNSS reception information is high, it means that the location of the vehicle is determined using the GNSS reception information when GNSS information with little reception error is received as in an open area, and the GNSS reception information If the reliability criterion is low, it means that the location of the vehicle is determined using the GNSS reception information even if GNSS information including some reception errors is received.

Therefore, the lower the reliability criterion (ie, the reliability criterion of GNSS reception information) is set, the faster GNSS information meeting the criterion can be received. That is, the time to apply the GNSS reception information to determine the location of the vehicle can be shortened.

Herein, the process of resetting the reliability criterion of the GNSS received information (ie, the reliability criterion of the GNSS received information) (S106) will be described in more detail with reference to FIG. 3 below.

Meanwhile, when the reliability criterion of the GNSS reception information is reset (S106) as described above, the controller 130 determines whether the GNSS reception information is reliable (i.e., satisfies the reliability) according to the reset reliability criterion Do (S107).

According to the result of determining whether the GNSS reception information is reliable (i.e., satisfies reliability) (S107), if the GNSS reception information satisfies the reliability criterion (YES in S107), the control unit 130 controls GNSS reception When it is determined that the information is reliable, the location information and heading information of the vehicle (ie, the location information and heading information calculated by the estimation method) are corrected using the GNSS reception information (S109).

On the other hand, according to the result of determining whether the GNSS received information is reliable (ie, whether the reliability is satisfied) (S107), if the GNSS received information does not satisfy the reliability criterion (No in S107), the control unit 130 The position of the vehicle is estimated using information measured by at least one sensor (eg, an inertial sensor) of the sensor unit 120 (S108).

And the control unit 130 determines the position of the vehicle estimated by the corrected position information and heading information using the GNSS reception information, or the position of the vehicle estimated by the information measured by the sensor of the sensor unit 120 is output (S110).

3 is a flowchart for explaining a method of resetting the reliability criterion of GNSS reception information according to the period in the shaded area in FIG. is compared with a preset threshold value (S201).

As a result of the comparison (S201), if the duration (Duration) of the vehicle in the shadow section is not smaller than the preset threshold value (No in S201), the control unit 130 determines the reliability of the GNSS reception sensitivity information based on the threshold value Change (S202).

For example, when the duration of the vehicle in the shaded section (ie, the duration of driving in the shaded section) is greater than a preset threshold value, the sensor (ie, inertia) of the sensor unit 120 than when the duration is relatively short. Sensor) Due to the increase in the accumulated drift error, the trajectory error increases when the vehicle enters the shaded area. Therefore, if the duration of the shadow section (ie, the duration of the shadow section) increases, the threshold value of the signal noise ratio of the satellite signal to the number of satellites (ie, the GNSS reception sensitivity information) is proportional to the increased duration (Duration). Reliability criterion value) is changed to low (S202).

On the other hand, as a result of the comparison (S201), if the duration (Duration) of the vehicle in the shadow section is less than the preset threshold value (YES in S201), the controller 130 calculates the heading information and sensor using the GNSS received information The change rate of the heading information calculated using the inertial sensor of the unit 120 is calculated (S203).

Meanwhile, even if the sensitivity information of the GNSS reception information is reliable, inaccurate GNSS location information may be output due to various environmental factors. A reliability determination flag to be used as a criterion for determining whether or not to calculate vehicle location information is set (S204).

For example, previous and current heading change rates using GNSS reception information (e.g., heading change rate calculated using GNSS information received every second) and previous and current heading change rates using measurement information of inertial sensors (e.g., 1 If the difference is greater than the threshold (e.g., the previous and current heading change rates using GNSS information are 5, and the inertial sensor information Assuming that the previous and current heading change rate using 1 is 1, and the difference is greater than the threshold value 3), the control unit 130 determines that the location information calculated by the GNSS reception information is inaccurate and determines GNSS reliability Set the flag to 0.

Accordingly, if the GNSS reliability determination flag is 1, it means that the location information calculated using GNSS information is accurate, and if the GNSS reliability determination flag is 0, even if the sensitivity information of the GNSS reception information is reliable. This means that inaccurate GNSS location information can be output.

The GNSS reliability judgment flag set as above resets the reliability judgment standard of GNSS reception information (e.g., when inaccurate GNSS location information using GNSS reception information can be output, resets the reliability judgment standard of GNSS reception information to a high level) used to do

That is, the control unit 130 resets the GNSS reliability criterion using the threshold criterion for determining the reliability of the GNSS reception sensitivity information changed in step S202 or the GNSS reliability decision flag set in step S204. (S205).

In addition, although not specifically shown in the drawing, when a predetermined time elapses after resetting the GNSS reliability criterion, the controller 130 automatically changes the GNSS reliability criterion to the previous GNSS reliability criterion.

As described above, the present embodiment allows the reliability criterion of GNSS reception information to be reset variably according to the driving situation in the shaded section, so that a lot of error is caused by dead reckoning when moving out after driving in a dead reckoning section for a long time. There is an effect of quickly correcting the accumulated driving direction and location information of the vehicle.

The present invention has been described above with reference to the embodiments shown in the drawings, but this is only exemplary, and those skilled in the art can make various modifications and equivalent other embodiments. you will understand the point. Therefore, the technical protection scope of the present invention should be determined by the claims below.

110: GNSS receiver
120: sensor unit
130: control unit
140: timer unit
150: position correction unit

Claims (8)

Checking, by a control unit, whether or not GNSS (Global Navigation Satellite System) information is received;
If the GNS information is not received, the controller determines that a shadow section has entered and measures a duration of the shadow section;
resetting, by the control unit, a criterion for determining reliability of the GNS information based on the measured duration of the shaded section;
determining, by the controller, whether the GNS information satisfies the reliability criterion according to the reset reliability criterion; and
If the GNS information satisfies the reset reliability criterion, correcting, by the control unit, location information and heading information using the GNS information,
In the step of resetting the criterion for determining the reliability of the GNS information,
Compares the duration of the shadow section with a preset threshold value, and if the duration of the shadow section is not smaller than the preset threshold value, the controller determines the reliability of the sensitivity information of the GNS information A method for determining dynamic reliability of a dead reckoning system based on GNS, characterized by changing a threshold criterion and resetting a criterion for determining reliability of GNS information therefrom.
delete According to claim 1,
If the duration of the shaded section is less than a preset threshold value,
The control unit calculates the rate of change of the previous and current heading information using the GNS information, calculates the rate of change of the previous and current heading information using the inertial sensor of the sensor unit, and calculates the rate of change of the heading information using the GNS information and By comparing the heading change rate calculated using the inertial sensor,
Based on the calculated difference in the rate of change of the heading information, if the difference in the rate of change is less than or equal to the threshold value, a GNSS reliability decision flag is set to 1, and if the difference in the rate of change is greater than the threshold value, the GNSS reliability decision flag is set to 0. A method for determining dynamic reliability of a GNS-based dead reckoning system, further comprising; setting.
The method of claim 3, according to a set value of the GNSS reliability determination flag,
If the GNSS reliability determination flag is 0, the control unit means that inaccurate GNSS location information may be output even if the sensitivity information of the GNS information is reliable, so resetting the reliability determination criterion of GNSS information A method for determining dynamic reliability of a GNS-based dead reckoning system, characterized in that.
A GNS receiver for receiving GNSS (Global Navigation Satellite System) information;
a timer unit for measuring a duration of a shadow section when entering a shadow section in which the GNS information is not received; and
Resetting the reliability criterion of the GNS information based on the duration of the measured shaded section, and determining whether the GNS information satisfies the reliability criterion according to the reset reliability criterion, If the GNS information satisfies the reset reliability criterion, a control unit for correcting location information and heading information using the GNS information;
The control unit,
In order to reset the criterion for determining the reliability of the GNS information,
Compare the duration of the shaded section with a preset threshold, and if the duration of the shaded section is not less than the preset threshold,
An apparatus for determining dynamic reliability of a dead reckoning system based on GNS, characterized in that a threshold criterion for determining reliability of sensitivity information of GNS information is changed and the reliability criterion of GNS information is reset therefrom.
delete The method of claim 5, wherein the control unit,
If the duration of the shaded section is less than a preset threshold value,
After calculating the rate of change of the previous and current heading information using the GNS information, and calculating the rate of change of the previous and current heading information using the inertial sensor of the sensor unit, the calculated heading change rate and the inertial sensor using the GNS information By comparing the heading change rate calculated using
Based on the calculated difference in the rate of change of the heading information, if the difference in the rate of change is less than or equal to the threshold value, a GNSS reliability decision flag is set to 1, and if the difference in the rate of change is greater than the threshold value, the GNSS reliability decision flag is set to 0. An apparatus for determining dynamic reliability of a GNS-based dead reckoning system, characterized in that for setting.
The method of claim 7, wherein the control unit,
Depending on the set value of the GNSS reliability determination flag, if the GNSS reliability determination flag is 0, even if the sensitivity information of the GNS information is reliable, it means that inaccurate GNSS location information can be output. , Dynamic reliability determination apparatus of a GNS-based dead reckoning system, characterized in that for resetting the reliability determination criteria of GNSS information.

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