JPH0735636A - Sensitivity correction of angle sensor of navigator - Google Patents

Abstract

PURPOSE:To provide a sensitivity correction method of a gyro capable of correcting sensitivity change accompanying a change with the passage of time of the gyro as it is mounted on a moving body and securing precision necessary for navigation. CONSTITUTION:An angle forming between a linear part from course data of a predetermined set running course and its next linear part is taken out, the former linear part has a sufficient distance (e.g. 500m) and a point wherein the angle of a corner forming between the former linear part and its next linear part has a sufficient angle (e.g. 80 deg.) is selected (S1). A car runs on a set course and collection processing of actually measured data of a gyro is performed (S2). Correction data are found as xj=Qj/alphaj from a point curve angle alphaj of the j point stored in a memory 10 as the actually measured data Qj of a j-th point (j=1, 2,...) and the course data. After the calculation of the all points is completed, an average value of correction data xj of the all points is obtained and made a sensitivity correction coefficient of the gyro (S3). The sensitivity correction coefficient of the gyro obtained in the above steps is stored in a fixed memory (S4).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gyro used for a navigation system of a mobile body, and more particularly to a gyro sensitivity correction method and a navigation device using the correction method.

[0002]

2. Description of the Related Art A navigation system for a moving body, such as a car, measures a change in azimuth with an angle sensor, and uses the result to display the position of the vehicle on a map displayed on a display device, so that the driver can see it. The purpose is to recognize the current position. Then, when the position display is performed in a short cycle (for example, a cycle of 1 to 2 seconds), the current position is relatively calculated based on the position of the vehicle one second before from the angle change amount and the movement distance amount from the distance sensor in the cycle. (Debt / reckoning processing),
Further, the position on the map or course is calculated (map matching processing) and displayed based on the map information or route setting course information possessed by the navigation system.

Further, although the conventional navigation system uses a gyro as an angle sensor, the sensitivity correction of the gyro has not been performed as a navigation device. The reason for this is that it was difficult to measure the sensitivity after the gyro was installed in the navigation device and attached to the moving body.

For example, a navigation system installed in a car
When trying to measure the sensitivity of the gyro with the system, you drive on a road with a clear angle and make a turn to collect the measurement data, or put the car on a device such as a turntable and rotate it by a certain angle. Therefore, it is difficult to obligate the user to perform such an operation in order to correct the sensitivity of the gyro.

[0005]

On the other hand, if the sensitivity change due to the change with time of the gyro is not corrected, the error included in the calculation result of the dead reckoning process becomes large, and the map matching process using the result of the dead reckoning process becomes large. The result is that the navigation display appears as if the car is off the set course despite the fact that the car is traveling correctly on the set course. There was a problem that

Therefore, conventionally, navigation devices have been
Without using a gyro with a large change over time (for example, a piezoelectric vibration gyro that is inexpensive but has a large change over time), use an expensive gyro with a small change over time (for example, an optical fiber gyro or a gas rate gyro). It was Here, if the gyro sensitivity correction can be performed without being mounted on the moving body while being incorporated in the navigation device, instead of using the gyro separately, the navigation device can be inexpensive instead of the expensive optical fiber gyro or gas rate gyro. A piezoelectric vibration gyro can be used, which can contribute to the spread of navigation systems.

In view of the above problems, the present invention has been made to solve the above problems, and corrects the sensitivity change of the gyro used in the navigation device with the passage of time while being mounted on the moving body. , It is an object of the present invention to provide a sensitivity correction method for a gyro that can ensure the accuracy required for navigation.

[0008]

In order to achieve the above object, a method of correcting the sensitivity of an angle sensor according to a first aspect of the present invention is directed to an angle sensor, a distance sensor, and at least the distance and the corner of each straight line portion of a running course. In a moving body equipped with a navigation device having a storage unit that stores predetermined course data including angles, a processing unit, and a display unit, angle data collection based on the distance and angle of each straight line portion of the predetermined course data. Outputting data of angle sensor for each extracted angle data collection point by extracting points, registering the extracted angle data collection points and angle data, running a moving body on a predetermined traveling course and operating a navigation device. After completion of traveling on a predetermined traveling course, the correction data for each angle data collection point of the angle sensor is calculated and calculated. The average value of each correction data is calculated and stored in the storage unit as a sensitivity correction coefficient, and the sensitivity correction processing of the angle sensor is performed by the sensitivity correction coefficient when the moving body travels next time. .

A second invention is characterized in that, in the sensitivity correcting method for the angle sensor of the first invention, the angle sensor is a piezoelectric vibrating gyro.

According to a third aspect of the present invention, in the angle sensor sensitivity correction method according to the first aspect of the present invention, the angle data collection points are extracted such that the straight line distance of each straight line portion of a predetermined traveling course is a predetermined value or more, and This is performed by setting a bending angle at which the absolute value of the bending angle formed by the straight line portion and the next straight line portion is a predetermined value or more as a data collection point.

According to a fourth aspect of the present invention, in the angle sensor sensitivity correction method according to the first aspect of the present invention, the navigation device further includes an input unit, and after the traveling of the predetermined traveling course is completed, the moving body is correctly moved on the predetermined traveling course. Confirmation input whether or not the vehicle has traveled, and only when there is a confirmation input that the mobile body has correctly traveled on a predetermined traveling course, calculation processing of correction data for each angle data collection point of the angle sensor is performed. It is characterized by

[0012]

With the above structure, the sensitivity correcting method for the angle sensor according to the first and second aspects of the present invention extracts the angle data collection points based on the distance and the angle of each straight line portion of the course data,
The extracted angle data collection points and angle data are registered, the navigation device is operated by running the moving body on a predetermined traveling course, and the output data of the angle sensor for each extracted angle data collection point is collected, After the traveling of the traveling course of, the process of calculating the correction data for each angle data collection point of the angle sensor is performed, the average value of each calculated correction data is calculated, and the sensitivity correction coefficient is stored in the storage unit. When the moving body travels from, the sensitivity correction processing of the angle sensor is performed by the sensitivity correction coefficient.

A third aspect of the present invention is the angle sensor sensitivity correction method according to the first aspect of the present invention, wherein the straight line distance of each straight line portion of a predetermined traveling course is a predetermined value or more, and the straight line portion and the next straight line portion. A bend angle whose absolute value of the bend angle is equal to or greater than a predetermined value is extracted as a data collection point.

According to a fourth aspect of the present invention, in the angle sensor sensitivity correction method according to the first aspect of the present invention, the navigation device further includes an input unit, and after the traveling of the predetermined traveling course is completed, the moving body correctly moves on the predetermined traveling course. Confirmation input whether or not the vehicle has traveled, and only when there is a confirmation input that the mobile body has correctly traveled on a predetermined traveling course, calculation processing of correction data for each angle data collection point of the angle sensor is performed. .

[0015]

FIG. 1 is a block diagram showing a basic configuration of a gyro sensitivity correction method according to the present invention. As a precondition, a traveling course in which a moving body travels is set in advance, and this gyro sensitivity correction method is set. It is assumed that the navigation device to which is applied stores course data (set course data) indicating the distance of the set course and the angle of the corner. At this time, the sensitivity correction is performed through the following four steps S1 to S4.

[S1] Extraction of angle data collection points from the set course data The angle data collection points are extracted from the set course data and registered (stored) in the memory. [S2] Collection of actual measurement data of gyro by traveling on set course Obtaining gyro output data for each angle data collection point extracted by driving a moving body, traveling a set planned traveling course and operating a navigation device To collect (memorize). The collected gyro data may be temporarily stored until the next step S3 ends.

[S3] Calculation and Saving of Gyro Sensitivity Correction Coefficients After completion of the set planned running course, correction data for each gyro angle data collection point is calculated, and an average value of the calculated correction data is obtained. And save it as a sensitivity correction coefficient. [S4] The gyro sensitivity is corrected by the above-described sensitivity correction coefficient during the next traveling. It should be noted that, before calculating the correction data for each gyro angle data collection point in step S3, a process of causing the driver to determine whether or not the moving body has correctly traveled on the planned traveling course may be inserted. Good.

FIG. 2 is a block diagram showing an example of the configuration of a navigation device to which the gyro correction method according to the present invention is applied. The navigation device of the embodiment is a vehicle-mounted navigation device in which a moving body is a car. In FIG. 2, 1 is a distance sensor, 2 and 4 are interface circuits, and 3 is a gyro as an angle sensor. In the embodiment, a piezoelectric vibration gyro is used. Reference numeral 5 denotes a process, and in the embodiment, a CPU 6 as a control unit, a navigation system, a ROM 7 storing a program for executing the gyro sensitivity correction method according to the present invention, and a RAM 8 used for executing those programs. , And I / O interface 9
A microcomputer having and is used. Furthermore,
Reference numeral 10 is a storage unit for storing set course data and map information used in the navigation system. In the embodiment, a CD (compact disc) is used. Reference numeral 11 is a storage means for storing a sensitivity correction coefficient, which will be described later, using a non-volatile RAM, and 12 is a display unit for displaying the current position of the vehicle obtained from the execution result of the navigation system. Is an input device having an input key and / or an input switch.

In the navigation device of FIG. 2, the outputs from the distance sensor 1 and the piezoelectric vibration gyro 3 are sampled at fixed time intervals by the interface circuits 2 and 4 in order to perform autonomous navigation, converted into digital data, and converted into a microcomputer. Enter in 5. Further, the result of the navigation processing by the microcomputer 5 is displayed on the CRT, LCD, display or the like via the display unit 12.

An example of obtaining the sensitivity correction coefficient by the vehicle-mounted navigation device of FIG. 2 will be described below. For the sake of explanation, the planned traveling course as shown in FIG. 6 is set in advance from the current position of the vehicle to the destination, and the course data (see FIG. 7) indicating the distance and the angle of the turning angle of the set course are displayed in a table format. It is assumed to be stored in the memory 10. In FIG. 6, point A is a start point, M is a destination point, and “clear turn” (described later) are points B, C, and L. Points D to K are gentle curves and cannot be used for gyro sensitivity correction.

<1. Extraction processing of angle data collection points from set course data (S1)> In this case, the set planned traveling course (FIG. 6) is formed by a certain line segment and the next line segment, as shown in FIG. When the angle is defined by 74 °, “clear bend” is selected, and here, “clear bend” means that the preceding line segment has a sufficient distance (line segment length), In addition, it is a bend angle at which the angle of the bend angle between the preceding line segment and the following line segment is sufficiently large. For example,
Sufficient distance over 500m (meter), angle 80
Degree of bend is sufficiently large above °. FIG. 3 is a flowchart showing the operation of the extraction processing of the angle data collection points from the set course data, and the process will be described below.

[S11, S12] The microcomputer 5 first reads out the course data of the memory 10 and selects "clear turn", so that it is judged for each line segment 71 whether or not it is 500 m or more from the turn before and after the turn. If it is less than 500 m from the turn, it is determined that there is not enough distance and the process proceeds to step S15. For example, for line segment 1 (section “A-B”) as the line segment this time, step S11
Since the distance of line segment 1 is 1250m ≧ 500m, step S
When the distance of the next line segment 2 (section “B-C”) is checked by 12, 1000 m ≧ 500 m. Therefore, it is determined in step S13 whether the angle is sufficiently large. When the process proceeds and the line segment 3 is checked as the current line segment in step S11, the process proceeds to step S12 when 2150 ≧ 500 m, but the line segment 4
Is 250m <500m, the step S1
The process proceeds to step S15 without determining the angle of 3.

[S13] It is determined whether or not the absolute value of the angle of the current line segment is 80 ° or more. If the absolute value is 80 ° or less, the process proceeds to step S15. For example, step S11
If the current line segment is the line segment 1, the absolute value 90 ≧ 80 of the angle of the line segment 1 + 90 ° is 90 ≧ 80. Therefore, the process proceeds to the next step S14, but the current line segment of the step S11 is the line segment 3 In this case, since the absolute value of the angle of the line segment 3 + 70 ° is 70 ≧ 80, the next step S14 is executed without executing the step S15.
Move on to. [S14] The number of the line segment and the angle of the line segment that have cleared the determinations in steps S11 to S13 are the angle data collection points (in FIG. 8, the letters are used for explanation, but the above-mentioned “current line segment”). No. ”(hereinafter referred to as“ point ”) and its angle is the nonvolatile RAM 1
Register (store) in 1.

FIG. 8 shows points and their angles obtained in steps S11 to S13 using the set course data of FIG. 7 as an example. Point B (bent angle formed by line segment 1 and line segment 2 (see FIG. 6)), Point C (bent angle formed by line segment 2 and line segment 3) and point L (bent angle formed by line segment 11 and line segment 12) and their angles + 90 °, −150 °, +90
° is shown. [S15] It is determined whether or not the point extraction processing has been completed for all line segments of the set course data, and if there is an unprocessed line segment, the process returns to S11 and the steps from S11 onward are repeated to determine the next line segment. Perform processing. When the processing is completed for all the line segments, this processing (S1) is completed.

<Gyro Actual Measurement Data Collection Processing by Traveling on Set Course (S2)> FIG. 4 is a flowchart showing the operation of the gyro actual measurement data collection processing as a result of the vehicle traveling on the set course. The steps S21 to S29 are executed (repeated) every second. The process will be described below. Note that when the vehicle starts running, a navigation system (not shown) also starts operating at the same time. [S21] The extraction point and its angle data stored in the memory 10 are read out and stored in the RAM 8 to wait for the vehicle to start traveling from the start point A of the set course in FIG. [S22] When the vehicle starts traveling on the set course, the microcomputer 5 samples the distance data and the angular velocity data from the distance sensor 1 and the piezoelectric vibration gyro 3 through the interface circuits 2 and 4 at 1 ms. The sampling data is read by sampling at intervals.

[S23] The current position of the running vehicle is calculated from the above data. The calculation of the current position can be obtained by the navigation system. [S24] It is determined whether or not a point for which angle data is to be collected has been passed, and if the point has not been passed, the process proceeds to step 26. It should be noted that whether or not the vehicle has passed a point at which angle data should be collected is counted every time the vehicle turns, and the count number is compared with the extraction point (line segment number) of the RAM 8 to determine the count number. If the points (numbers) match, it is determined that the points have been passed. [S25] When the vehicle passes the point where the angle data should be collected, the RAM 8 stores the angle data (actual measurement data) obtained from the angular velocity data from the piezoelectric vibration gyro 3 at that timing.

[S26] It is determined by the navigation system whether or not the vehicle is traveling on the planned course. When it is determined that the vehicle is traveling on the planned course, the process proceeds to step S29, it is determined whether the traveling is completed, and if it is completed, the data collection is also completed. Below that, continue to collect. [S27] The navigation system determines whether or not the destination M in FIG. 6 has been passed, and if the destination M has been passed, the process of S28 is not performed. In this case, a warning or display may be given to prompt the driver to confirm whether or not the destination has passed the planned course, and the determination may be made by the confirmation input from the input device 13. [S28] If the vehicle has not deviated from the planned course and has not passed the destination point M, it is assumed that the vehicle did not correctly travel on the planned course, and all the actual measurement data stored in step 25 are erased.

<Calculation and Storage Processing of Gyro Sensitivity Correction Coefficient (S3)> FIGS. 4A and 4B show gyro correction data after the vehicle has traveled on the set course of steps S21 to S28 described above. 5 is a flowchart showing the operation of the calculation and storage processing of FIG. The process will be described below with reference to FIG. Note that FIG. 4B shows in detail the “calculation and storage of gyro correction data” in FIG. 4A. [S31] It is confirmed whether or not the vehicle has arrived at the destination point M.
This confirmation is based on the start point A stored in the RAM 8.
To the destination point M, the distances of the respective line segments of the course data are added, and the comparison is made with the integrated value of the traveled distance obtained based on the data from the distance sensor 1 of the traveling vehicle. If the destination M has not arrived, the confirmation is repeated until it arrives. In the determination, the distance of each line segment of the course data from the start point A to the destination point M is compared with the integrated value of the traveling distance, and the integrated value of the traveling distance is added value ± γ.
(Γ is a permissible error).

[S32] It is checked whether or not the angle data (actual measurement data) corresponding to the points for which the angle data is to be collected are stored in the RAM 8 by the number of points. If the angle data is not stored for the number of points, it is determined that the vehicle did not correctly travel on the planned course, and the calculation and storage processing of the sensitivity correction coefficient of the gyro are not performed, and the processing ends.

[S33] When the angle data is stored for the number of points, the driver is prompted to confirm whether or not the calculation and storage processing of the gyro sensitivity correction coefficient may be performed. In order to prompt the confirmation input, for example, "If the driver can run the entire course as planned, switch" S "
A message such as "Press W" is displayed. This step can be omitted as described above (if omitted, it is omitted together with the following steps S34 and S40). However, if this input request is not issued, the processing unit (microcomputer 5) of the navigation device uses the sensor data (angle data from the gyro 3).
Estimate your location based only on. In such a case, if the sensor data is rigorously evaluated, there is a possibility that the vehicle is judged to be off the course due to an error in the course data or the like, although the vehicle is on the set course. Therefore, although a margin is usually given to the sensor data, the margin may give a weak determination of the current position, and it may not be possible to determine that the current position is out of the course even if the vehicle travels on an incorrect course. As described above, in order to reduce the possibility that the error in the gyro sensitivity correction when using the traveling data increases, the above-described input request is made.

[S34] In step S33, the input unit 13
It is determined whether or not the switch "SW" (not shown) has been pressed. If the switch SW has not been pressed within the predetermined time, the process proceeds to step S40. [S35 to S39] Gyro sensitivity correction coefficient calculation and storage processing is performed, and the processing ends. Note that these steps will be described with reference to FIG. [S40] If it is not determined whether the predetermined time has passed, the process returns to step S34. If the switch "SW" is not pushed even after a lapse of a certain time, it is determined that the vehicle did not travel properly on the planned course, and the calculation and storage processing of the sensitivity correction coefficient of the gyro are not performed, and the processing ends. In this case, all the actual measurement data stored in step 25 are deleted.

<Calculation of Gyro Sensitivity Correction Coefficient> FIG. 4
(B) is a flowchart showing a detailed operation (steps S35 to S39) of the calculation and storage processing of the gyro correction data based on the sensitivity characteristic of the piezoelectric vibration gyro 3 described above. Here, the sensitivity characteristic of the piezoelectric vibration gyro 3 is as follows when the temperature is constant. First, assuming that the car turns through the corner in 5 seconds, 5000 sampling data can be obtained when A / D converting the gyro output at the sampling interval of 1 ms (milli-reset) by the A / D converter 4. Becomes The bending angle Q [deg] at this time is from the sampling data,

[0033]

[Equation 1]

It is calculated by However, k is a sensitivity constant [deg
/ V], E _n is the n-th A / D conversion data [v]. Note that [v] means a voltage unit. On the other hand, if the bend angle is α [deg], the sensitivity correction coefficient x is calculated by the following equation (2).

## EQU00002 ## x = Q / .alpha. (2) Therefore, after the sensitivity correction coefficient x is obtained, the curve is turned with the sensitivity change being 0 (zero), and the sampling data from the gyro output at that time is Q [deg]. If

## EQU00003 ## Q / x = Q.times. (. Alpha./Q)=.alpha. (3) is corrected, and it can be estimated that the angle of the actually bent corner due to the running of the vehicle is .alpha. [Deg].

Hereinafter, description will be given with reference to FIG. [S35] j (j = 1, 1 stored in the RAM 8)
Sensitivity correction data x _j is obtained from the actual measurement data Q _j of the (2, ...) th point and the bending angle α _j of the point j point stored in the memory 10 as the course data (here, the sensitivity correction data x _j is From the above equation (2), x _j = Q _j
/ Α _j ). The sensitivity correction data x _j thus obtained is stored in the coefficient memory (for example, RAM 8). It should be noted that FIG. 9 shows an example of the angle α of the extraction point and the actually measured data Q of the gyro 3 in FIG.

[S36] It is determined whether or not the calculation and storage of the sensitivity correction coefficient have been completed for all the extraction points stored in the memory 10, and if so, the process proceeds to step S38. Note that FIG. 10 shows an example of the correction coefficient obtained for each corner of the extraction point of FIG. 8 (in FIG. 10, a value of “1” is a correction coefficient of point B, a value of “2” is a correction coefficient of point C, The value of "3" is the correction coefficient of the point L). [S37] If the calculation of all points has not been completed, the points to be calculated are updated (for example, if the current calculation is performed for point B in FIG. 8, the next point C is to be calculated). Change the subscript j so that
Return to S35. [S38] The average value of the values of the extraction points stored in the correction coefficient memory for each bend angle is calculated and used as the gyro sensitivity correction coefficient. It should be noted that the method shown in FIG.
When the vehicle travels on the set traveling course of, the sensitivity correction coefficient of the gyro 3 = “1.055” is obtained.

[S39] The gyro sensitivity correction coefficient obtained in the above step is stored in the nonvolatile RAM 11. Figure 1
Reference numeral 1 represents an actual measurement value of the sensitivity change of the piezoelectric vibration gyro. It can be seen from Fig. 11 that the sensitivity has decreased by 5% after about 3 months have passed (∵-100mv / 2v = -100 /
2000 = -0.05). FIG. 12 shows the operation principle of the piezoelectric vibrating gyro and shows that a constant voltage is output for an angular velocity given from the outside.

[0038]

As described above, according to the gyro sensitivity correction method of the present invention, the sensitivity change due to the change with time of the gyro is moved only by setting the traveling course in the normal navigation use state and traveling the course. The accuracy required for navigation can be ensured by making corrections when incorporated in a navigation device mounted on the body. Further, since the gyro sensitivity correction method of the present invention need only be added as software without changing the hardware configuration of the conventional navigation device, it can be applied to the conventional navigation device.

[Brief description of drawings]

FIG. 1 is a block diagram showing a basic configuration of a gyro sensitivity correction method according to the present invention.

FIG. 2 is a block diagram showing a configuration example of a navigation device to which a gyro sensitivity correction method according to the present invention is applied.

FIG. 3 is a flowchart showing an operation of extraction processing of angle data collection points from set course data.

FIG. 4 is a flowchart showing an operation of a process of collecting actual measurement data of a gyro, which is repeatedly executed every second while the vehicle is traveling on the set course.

FIG. 5 is a flowchart showing an operation of calculation and storage processing of a gyro sensitivity correction coefficient.

FIG. 6 is an example of a set traveling course.

FIG. 7 is an example of course data of the set traveling course of FIG.

FIG. 8 is an example of extraction points and their angles based on set course data.

FIG. 9 is an example of actual measurement data of angles of extraction points and gyros.

FIG. 10 is an example of correction data obtained for each extraction point.

FIG. 11 is an example of an actually measured value of a sensitivity change of a piezoelectric vibration gyro.

FIG. 12 is an explanatory diagram of the operating principle of the piezoelectric vibrating gyro.

[Explanation of symbols]

 1 distance sensor 3 gyro (angle sensor) 5 microcomputer (processing unit) 10 CD (storage unit) 11 non-volatile RAM (storage unit) 12 display unit 13 input device (input unit)

Claims (4)

[Claims] 1. An angle sensor, a distance sensor, a storage unit for storing predetermined course data including at least a distance of each straight line portion of a traveling course and an angle of a bend, and a processing unit.
In a moving body including a navigation device having a display unit, angle data collection points are extracted based on the distance and angle of each straight line portion of the predetermined course data, and the extracted angle data collection points and angle data are registered. Then, the movable body is caused to travel on the predetermined traveling course to operate the navigation device, and the output data of the angle sensor for each of the extracted angle data collection points is collected, and after the traveling of the predetermined traveling course is completed, The correction data is calculated for each angle data collection point of the angle sensor, the average value of the calculated correction data is calculated, and it is saved as a sensitivity correction coefficient in the storage unit. A sensitivity correction method for an angle sensor, wherein sensitivity correction processing for an angle sensor is performed using the sensitivity correction coefficient. 2. The sensitivity correction method for an angle sensor according to claim 1, wherein the angle sensor is a piezoelectric vibration gyro. 3. The method for correcting the sensitivity of an angle sensor according to claim 1, wherein the extraction of the angle data collection point is performed such that the straight line distance of each straight line portion of a predetermined traveling course is a predetermined value or more and A method for correcting sensitivity of an angle sensor, characterized in that a bending angle whose absolute value of a bending angle formed by the next straight line portion is a predetermined value or more is used as a data collection point. 4. The method for correcting the sensitivity of an angle sensor according to claim 1, wherein the navigation device further includes an input unit, and whether or not the moving body has correctly traveled on the predetermined travel course after the travel of the predetermined travel course is completed. It is characterized in that correction data is calculated for each angle data collection point of the angle sensor only when there is a confirmation input that the mobile body has correctly traveled on a predetermined traveling course. A method for correcting the sensitivity of the angle sensor.