JPH0735565A - Calibration value determination method for distance sensor of on-vehicle navigation device - Google Patents

Abstract

PURPOSE:To provide a calibration value determination method for the distance sensor of an on-vehicle navigation device, allowing the value to be determined easily, quickly and at any place. CONSTITUTION:A vehicle is parked on a horizontal and flat road. Regarding a wheel connected to a distance sensor, two wheel height points L1 and L2 are measured as the height of two points J and K where a vertical segment 21 passing the center of an axle and perpendicular to the road intersects the circumference of the concentric circle of the wheel. Then, the measured values of L1 and L2, and speed determination factors R1 and R2 corresponding to the type of the distance sensor are inputted to the processing section of a navigation device. Also, after a travel distance per revolution is calculated as L3=pi(L1+L2)alpha where pi is a ratio of the circumference of a circle to its diameter, and alpha is a correction factor, a calibration value is obtained from the values of L3, and factors R1 and R2 as C=(L3XR1)/R2. In this case, when the distance sensor is a wheel sensor, the factor R1 denotes rubber length and R denotes magnetism pattern length. Also, when the distance sensor is a travel speed sensor, R1 denotes a gear ratio and R2 denotes the pulse number of the travel speed sensor per revolution of the axle.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to calibration of a distance sensor, and more particularly to a method of determining a calibration value of a distance sensor of an on-vehicle navigation device.

[0002]

2. Description of the Related Art Conventionally, a navigation system calibrates and uses a distance sensor. In particular, since the vehicle-mounted navigation device has different tire diameters and vehicle weights from vehicle to vehicle, even if the same type of distance sensor is used, its output is different (specifically, the distance corresponding to one pulse output from the distance sensor is different). Will be). Therefore, in order to calibrate the distance sensor, the vehicle is actually used to drive on a road of a predetermined distance, the output pulse from the distance sensor is counted by the navigation device, and "distance" / " Number of pulses ”=
The calculation of the “calibration value” is performed to find the calibration value of the distance sensor, which is stored in the non-volatile memory of the device. This calibration value is used for navigation and the number of pulses from the distance sensor is counted while driving to determine the “pulse count”. ”ד Calibration value ”=“ distance ”was calculated to find the running distance. Further, as the distance sensor, there is a wheel sensor or a vehicle speed sensor (described later).

4 and 5 are examples of vehicle-mounted navigation devices using wheel sensors 41 and 51 as distance sensors, respectively. Further, FIG. 6 is an example (partial view) using a vehicle speed sensor 61 for an ECCS (Engine Centralized Control System). The vehicle speed sensor 61 inputs a two-pulse signal output via a speedometer to the ECCS 62 to obtain a vehicle speed signal,
The signal is diverted and used for navigation.

[0004]

However, the conventional method for calibrating the navigation device has a problem that it cannot be easily performed when the vehicle is actually driven to calibrate the distance sensor. As an example, a commercially available navigation device runs a straight course of 2.5 km or more and stores calibration (CALIBRATION; distance sensor data in a storage unit of the navigation device).
The same applies hereinafter), but there are the following problems.

First, the starting point and the ending point of the vehicle must be clear. An intersection is often selected as a clear position, but stopping at the intersection and operating the navigation device interferes with running of another vehicle. Next, finding a flat road without steep slopes makes it difficult to actually drive.When you drive near your home, you can easily select a road because you have a sense of land. It takes time to select a road and search for a target, and it is difficult to make a mistake in the traveling course.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a method for determining a calibration value of a distance sensor of a vehicle-mounted navigation device that can be easily and quickly performed anywhere. .

[0007]

In order to achieve the above object, a method of determining a calibration value of a distance sensor of a vehicle-mounted navigation device of a first invention is a distance sensor, an angle sensor,
In a vehicle including a navigation device having a storage unit, a processing unit, an input unit, and a display unit, a line segment that passes through the center of the wheel axle that gives distance information to a distance sensor and is perpendicular to the ground surface is the center of the axle. It is characterized in that the distances from the ground surface at two points intersecting the circumference of an arbitrary concentric circle as the center are measured to obtain measured values L1 and L2, and the calibration value of the distance sensor is obtained based on the measured values L1 and L2. .

A method of determining a calibration value of a distance sensor of a vehicle-mounted navigation device according to a second aspect of the present invention includes a wheel sensor as a distance sensor, an angle sensor, a storage unit, a processing unit, an input unit, and a display unit. In a vehicle equipped with the navigation device, a line segment passing through the center of an axle of a wheel provided with a wheel sensor and perpendicular to the ground surface measures the distance from the ground surface at two points where the line segment intersects with the circumference of a concentric circle of the wheel wheel. Measured value L
1, L2 are obtained, and the calibration value C of the distance sensor is obtained based on the measured values L1, L2 and the predetermined rubber length RL and the magnetic pattern length RM.

A third invention is a method for determining a calibration value of a distance sensor of a vehicle-mounted navigation device according to the second invention, wherein a calibration value C of the distance sensor is obtained based on the following mathematical formula. A method for determining a calibration value of a distance sensor. C = (L3 × RM) / RL L3 = π (L1 + L2) · α where π is the circular constant, a
Is a correction coefficient.

According to a fourth aspect of the present invention, there is provided a method for determining a calibration value of a distance sensor of a vehicle-mounted navigation device, comprising a vehicle speed sensor as a distance sensor, an angle sensor, a storage section, a processing section, an input section and a display section. In a vehicle equipped with such a navigation device, a line segment passing through the center of the wheel axle provided with a vehicle speed sensor and perpendicular to the ground surface measures and measures the distance from the ground surface at two points where the line segment intersects with the circumference of the concentric circle of the wheel wheel. Value L1, L2
Is obtained, and the calibration value of the distance sensor is obtained based on the measured values L1 and L2, the predetermined gear ratio G, and the number of pulses P per revolution of the flexible shaft of the vehicle speed sensor.

A fifth aspect of the invention is the method for determining the calibration value of the distance sensor of the vehicle-mounted navigation device according to the second aspect of the invention, wherein the calibration value C of the distance sensor is obtained based on the following mathematical formula. C = (L3 × G) / P L3 = π (L1 + L2) · α where π is the circular constant, a
Is a correction coefficient.

According to a sixth aspect of the present invention, there is provided a method for determining a calibration value of a distance sensor for a vehicle-mounted navigation device, comprising: a navigation device having a distance sensor, an angle sensor, a storage section, a processing section, an input section and a display section. A method of determining a calibration value of a distance sensor of a vehicle-mounted navigation device, wherein the processing unit performs determination processing of a calibration value of the distance sensor by the following steps (1) to (5). (1) Discriminate the type of distance sensor. (2) A measured value L obtained by measuring the distance from the ground surface at two points where a line segment passing through the center of the wheel axle provided with the distance sensor and perpendicular to the ground surface intersects with the circumference of the concentric circle of the wheel wheel.
1 and L2 are input from the input unit. (3) The traveling distance L3 per one rotation of the wheel during traveling is calculated. Here, L3 = π (L1 + L2) · α, where π
Is a circular constant, and a is a correction coefficient. (4) The calibration value C is obtained from the traveling distance L3 per one rotation and the rotation speed determination constants R1 and R2 corresponding to the type of the distance sensor. Here, C = (L3 × R1) / R2
Is. (5) The calibration value C is stored in the storage unit.

[0013]

According to the method of determining the calibration value of the distance sensor of the vehicle-mounted navigation device according to the first aspect of the invention, the line segment that passes through the center of the wheel axle that gives distance information to the distance sensor and is perpendicular to the ground surface is the axis of the axle. Measured value L by measuring the distance from the ground surface at two points that intersect the circumference of any concentric circle centered on the center
1, L2 are obtained, and the calibration value of the distance sensor is obtained based on the measured values L1, L2.

In the method for determining the calibration value of the distance sensor of the vehicle-mounted navigation device according to the second aspect of the present invention, first, a line segment passing through the center of the wheel axle provided with the wheel sensor and perpendicular to the ground surface is a concentric circle of the wheel of the wheel. Measure the measured values L1 and L2 by measuring the distance from the ground surface at two points that intersect the circumference, and measure the measured values L1 and L2.
And a calibration value C of the distance sensor based on the predetermined rubber length RL and the magnetic pattern length RM.

According to a third aspect of the invention, in the method for determining the calibration value of the distance sensor of the vehicle-mounted navigation device according to the second aspect of the invention, the calibration value C of the distance sensor is obtained based on the following mathematical formula. C = (L3 × RM) / RL L3 = π (L1 + L2) · α where π is the circular constant, a
Is a correction coefficient.

In the method for determining the calibration value of the distance sensor of the vehicle-mounted navigation device according to the fourth aspect of the invention, first, a line segment passing through the center of the axle of the wheel provided with the vehicle speed sensor and perpendicular to the ground surface is a circle of concentric circles of the wheel of the wheel. The distances from the ground surface at two points intersecting the circumference are measured to obtain measured values L1 and L2, and the distances are based on the measured values L1 and L2, a predetermined gear ratio G, and the number of pulses P per revolution of the flexible shaft of the vehicle speed sensor. Find the calibration value of the sensor.

A fifth aspect of the present invention is the method of determining the calibration value of the distance sensor of the vehicle-mounted navigation device according to the fourth aspect, wherein the calibration value C of the distance sensor is obtained based on the following mathematical formula. C = (L3 × G) / P L3 = π (L1 + L2) · α where π is the circular constant, a
Is a correction coefficient.

A method of determining a calibration value of a distance sensor of a vehicle-mounted navigation device according to a sixth aspect of the present invention is a navigation device having a distance sensor, an angle sensor, a storage unit, a processing unit, an input unit, and a display unit. The processing unit performs the determination process of the calibration value of the distance sensor by the following steps (1) to (5). (1) Discriminate the type of distance sensor. (2) A measured value L obtained by measuring the distance from the ground surface at two points where a line segment passing through the center of the wheel axle provided with the distance sensor and perpendicular to the ground surface intersects with the circumference of the concentric circle of the wheel wheel.
1 and L2 are input from the input unit. (3) The traveling distance L3 per one rotation of the wheel during traveling is calculated. Here, L3 = π (L1 + L2) · α, where π
Is a circular constant, and a is a correction coefficient. (4) The calibration value C is obtained from the traveling distance L3 per one rotation and the rotation speed determination constants R1 and R2 corresponding to the type of the distance sensor. Here, C = (L3 × R1) / R2
Is. (5) The calibration value C is stored in the storage unit.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a block flow chart showing a basic configuration of a method for determining a calibration value of a distance sensor of a vehicle-mounted navigation device according to the present invention, and the method for determining the calibration value can be roughly classified into the following three steps. [S1] Measurement of vehicle Holly heights L1 and L2. [S2] Input of measured values L1 and L2 and constants to the navigation device. [S3] A calibration value in the navigation device is calculated. The constant input in step S2 and the formula for calculating the calibration value in step S3 differ depending on the type of the distance sensor. At the present time, as described above, there are two types of distance sensors of the vehicle-mounted navigation device, a wheel sensor and a vehicle speed sensor, so there are two types of constants and calculation formulas (described later). The method of determining the calibration value of the distance sensor will be described below with reference to FIG.

The hardware configuration of a navigation device (not shown) to which the present invention is applied may be a conventional navigation device, such as a distance sensor, an angle sensor, a storage unit for storing at least map information, and a device. A processing unit that includes a control unit that controls the entire control, calculates a current position of the vehicle based on distance information and angle information from the distance sensor and the angle sensor, and an input unit that inputs information necessary for operating the navigation device. It suffices to have a display unit that displays the calculated current position together with the map information.

<Measurement of vehicle wheel heights L1 and L2 (S
1)> Stop the vehicle on a horizontal and flat road. Then, for a vehicle using a wheel sensor as a distance sensor, a wheel having a wheel sensor attached thereto, and for a vehicle using a vehicle speed sensor as a distance sensor, wheels connected to the vehicle speed sensor, a wheel height L1 as shown in FIG. Measure L2.

FIG. 2 is an example of a method for measuring the wheel heights L1 and L2. Regarding the method of obtaining the measured values L1 and L2, A, B, and
Although seven examples of C, D, E, F, and G are shown, the measured values L1 and L2 obtained in any of the examples may be used. The wheel heights L1 and L2 are obtained by measuring the height of the wheel 23 from the road at two points as shown in FIG. Specifically, a line segment 21 passing through the center of the axle and perpendicular to the road intersects the circumference of the concentric circles of the wheel. Measure the height of K (vertical distance from the road). When there are a plurality of concentric circles of the foil, the heights of two points where the circumference of any concentric circle and the line segment 21 intersect may be obtained.
In FIG. 2, 22 is a tire and 24 is a road surface. In addition, the driver of the vehicle may measure with a commercially available ruler,
In addition, it may be configured to automatically measure (for example, based on an optical distance measuring device).

<Measured values L1 and L to the navigation device
2 and input of constant (S2)> The measured values L1 and L2 are input to the processing unit of the navigation device. In addition, the following constants are input according to the type of the distance sensor, or these constants are stored in the storage unit in advance. (A) Input constant when the distance sensor is a wheel sensor Rubber length; RL Magnetic pattern length; RM (b) Input constant when the distance sensor is a vehicle speed sensor Gear ratio; G Number of pulses per wheel rotation of the vehicle speed sensor; P

These constants can be easily obtained by being determined as manufacturer specifications. Here, the “rubber length” is the length of the rubber magnet when the rubber magnet is attached to the wheel, and satisfies the relationship of RM × n = RL assuming that n pulses are generated in one rotation of the tire. To be decided. However, n is an integer length.

The "magnetic pattern length" is the length of the magnetic pattern recorded on the rubber, which is uniquely determined by the rubber and is usually described in the instruction manual or the like when the navigation system is purchased. There is. "Gear ratio"
Is determined for each vehicle and is determined by the product of the speedometer gear teeth and the final gear reduction ratio, and represents the number of revolutions of the flexible shaft per one revolution of the axle. "" And the like). "Number of pulses per revolution of the flexible shaft of the vehicle speed sensor" is also specified in the material issued by the manufacturer. The above-mentioned measured values L1 and L2 of the wheel height and the respective constants may be keyed in from the input section at the time of measurement,
As described above, each constant may be input together with other set values from the input unit during the initial (initial setting) operation of the navigation device and stored in the storage unit.

<Calculation of Calibration Value (S3)> A calibration value is calculated based on the wheel height measurement values L1 and L2 input in step S2 and the respective constants, and is stored in the memory (memory). First, the traveling distance L3 per one rotation of the tire during traveling is obtained from the measured wheel height values L1 and L2. Where L3 = π
(L1 + L2) α, π is the circular constant, and α is a correction coefficient, which is used to reduce the error, and α≈1.
The correction coefficient α can be determined as follows. Generally, when the radius of the outer diameter of the tire when the vehicle weight is 0 (zero) is L4, 2πL4>L3> π (L1 + L
2), and when divided by π (L1 + L2), (2L4
/ L1 + L2)> (L3 / π (L1 + L2))> 1. And the left side is about 1.1 according to actual measurement, so
It is possible to determine α in a range such that 1.1>α> 1. Therefore, α may be temporarily set in advance and then finely adjusted as needed. Further, in order to set α, it is only necessary to calibrate a large number of cars and obtain an average value.

Next, the following calculation is performed according to the type of sensor to obtain the calibration value C. (A) Input constant when the distance sensor is a wheel sensor C = (L3 × RM) / RL (b) Input constant when the distance sensor is a vehicle speed sensor C = (L3 × G) / P Calculated as above The calibration is completed by writing the value of the calibration value C that has been written to the nonvolatile memory.

FIG. 3 is a flow chart showing the operation of the processing unit when the processing unit of the navigation device executes the method for calibrating the distance sensor of the vehicle-mounted navigation device of the present invention. [S31] It is determined whether or not the distance sensor is the ECCS vehicle speed sensor. If the distance sensor is not the ECCS vehicle speed sensor, the process proceeds to S34. [S32, S33] In the case of the vehicle speed sensor for ECCS,
The gear ratio G is input as the rotation speed determination constant R1 corresponding to the type of distance sensor.

Next, the number of pulses P per revolution of the flexible shaft of the vehicle speed sensor is input as the revolution number determination constant R2 corresponding to the type of the distance sensor, and the routine proceeds to step 38. [S34] It is determined whether or not the distance sensor is a wheel sensor. If not, the process proceeds to step S37. [S35, S36] In the case of a wheel sensor, the rubber length RL is input as the rotation speed determination constant R1 corresponding to the type of distance sensor.

Next, the magnetic pattern length RM is input as the rotation speed determination constant R2 corresponding to the type of the distance sensor, and the process proceeds to step S38. [S37] The same calibration processing as in the conventional method is performed, and after the calibration processing in the conventional method is completed, the process proceeds to step S44. [S38, S39] Measured value L of the wheel height from the input section
1 and L2 are obtained. [S40] Traveling distance L per one tire rotation during traveling
Calculate 3 = π (L1 + L2) α. [S41] It is determined whether or not the distance sensor is the ECCS vehicle speed sensor. If the distance sensor is not the ECCS vehicle speed sensor, the process proceeds to S43. [S42] The calibration value C = (L3 × G) / P is calculated, and the process proceeds to step S44. [S43] The calibration value C = (L3 × RM) / RL is calculated. [S44] The calibration value C is stored in the non-volatile memory.

[0031]

As described above, according to the method of determining the calibration value of the distance sensor of the present invention, it is not necessary to actually travel on the road, and it is easy, short time, and anywhere on a flat place. However, the calibration value of the distance sensor can be determined and the calibration can be completed. Further, the calibration value of the distance sensor can be immediately determined and the calibration can be completed when the tires are replaced or when the weight of the vehicle changes significantly due to a change in the number of passengers.

[Brief description of drawings]

FIG. 1 is a block flowchart showing a basic configuration of a method of determining a calibration value of a distance sensor of a vehicle-mounted navigation device according to the present invention.

FIG. 2 is an example of a method for measuring foil height.

FIG. 3 is a flowchart showing the operation of the processing unit when the processing unit of the navigation device executes the method for calibrating the distance sensor of the vehicle-mounted navigation device of the present invention.

FIG. 4 is an example of a vehicle-mounted navigation device using a wheel sensor as a distance sensor.

FIG. 5 is an example of a vehicle-mounted navigation device using a wheel sensor as a distance sensor.

FIG. 6 is an example of a method using a signal from a vehicle speed sensor.

[Explanation of symbols]

 21 vertical line segment 22 tire 23 wheel L1, L2 wheel height measurement

Claims (6)

[Claims] 1. A vehicle including a navigation device having a distance sensor, an angle sensor, a storage unit, a processing unit, an input unit, and a display unit, wherein an axle of a wheel that gives distance information to the distance sensor. Measured values L1 and L2 are obtained by measuring distances from the ground surface at two points where a line segment that passes through the center and is perpendicular to the ground surface intersects with the circumference of an arbitrary concentric circle centered on the center of the axle. , L2 for obtaining the calibration value of the distance sensor, the method for determining the calibration value of the distance sensor of the vehicle-mounted navigation device. 2. A vehicle axle provided with a wheel sensor as a distance sensor, an angle sensor, a storage unit, a processing unit, an input unit, and a display unit. A line segment passing through the center of the wheel and perpendicular to the ground surface intersects with the circumference of the concentric circle of the wheel wheel 2
Measuring distances of the points from the ground surface to obtain measured values L1 and L2, and obtaining a calibration value C of the distance sensor based on the measured values L1 and L2 and a predetermined rubber length RL and magnetic pattern length RM. A method for determining a calibration value of a distance sensor of a featured vehicle-mounted navigation device. 3. The calibration method for a distance sensor of a vehicle-mounted navigation device according to claim 2, wherein the calibration value C of the distance sensor is obtained based on the following mathematical formula. How to determine the value. C = (L3 × RM) / RL L3 = π (L1 + L2) · α where π is the circular constant, a
Is a correction coefficient. 4. A vehicle axle including a vehicle speed sensor as a distance sensor, an angle sensor, a storage unit, a processing unit, an input unit, and a display unit, and a wheel axle provided with the vehicle speed sensor. The distance from the ground surface at two points where a line segment passing through the center of the wheel and perpendicular to the ground surface intersects with the circumference of a concentric circle of the wheel of the wheel, and obtains the measured values L1 and L2. The method for determining the calibration value of the distance sensor of the vehicle-mounted navigation device, wherein the calibration value of the distance sensor is obtained based on the gear ratio G and the number of pulses P per one rotation of the flexible shaft of the vehicle speed sensor. 5. The calibration method for a distance sensor of a vehicle-mounted navigation device according to claim 4, wherein a calibration value C of the distance sensor is obtained based on the following mathematical formula. How to determine the value. C = (L3 × G) / P L3 = π (L1 + L2) · α where π is the circular constant, a
Is a correction coefficient. 6. A navigation device having a distance sensor, an angle sensor, a storage unit, a processing unit, an input unit, and a display unit, wherein the processing unit performs the distance sensor according to the following steps (1) to (5). A method of determining a calibration value of a distance sensor of a vehicle-mounted navigation device, characterized in that the calibration value determination process is performed. (1) Discriminate the type of distance sensor. (2) A measured value L obtained by measuring the distance from the ground surface at two points where a line segment passing through the center of the wheel axle provided with the distance sensor and perpendicular to the ground surface intersects with the circumference of the concentric circle of the wheel wheel.
1 and L2 are input from the input unit. (3) The traveling distance L3 per one rotation of the wheel during traveling is calculated. Here, L3 = π (L1 + L2) · α, where π
Is a circular constant, and a is a correction coefficient. (4) The calibration value C is obtained from the traveling distance L3 per one rotation and the rotation speed determination constants R1 and R2 corresponding to the type of the distance sensor. Here, C = (L3 × R1) / R2
Is. (5) The calibration value C is stored in the storage unit.