JP3262051B2 - Vehicle position detecting device and position detecting method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a position detecting device and a position detecting method for an automatically-piloted vehicle, and more particularly to a vehicle position detecting device and a position detecting method for detecting a lateral position of a vehicle with respect to the center of a traveling lane. Regarding improvement.

[0002]

2. Description of the Related Art In general, a vehicle position detecting device in an automatic driving system for a vehicle includes, for example, a magnetic system, an optical system, an image processing system, and the like. For example, it is applied to unmanned vehicles that transport products, parts, and the like in factories.

In this magnetic system, the strength of the magnetic field generated by installing a guide cable in the center of the traveling lane of a vehicle or installing permanent magnets at predetermined intervals is provided. Is detected, and the position of the vehicle is controlled using the detection signal.

For example, in Japanese Utility Model Laid-Open No. 3-17806,
Magnets are arranged at regular intervals on the road surface along the planned track of the unmanned vehicle, and a plurality of Hall ICs for detecting a magnetic field by the magnet are arranged in a horizontal line on the bottom surface of the unmanned vehicle. The position of the unmanned vehicle with respect to the planned trajectory is determined from the geometric condition between the position of the IC and the distance of the magnet.

In this magnetic system, the magnetic field strength detected by the ball IC depends on the strength of the magnetic field generated by the induction cable or magnet and the distance between the ball and the induction cable or magnet. In some cases, it is very weak and geomagnetic (3 × 10 ^-5
T) It may be necessary to detect the magnetic field strength below.

[0006] Moreover, usually, since many vehicles are composed of a magnetic material, is magnetized, the strength of magnetization varies by the vehicle, a strong location ^10-4
It reaches T order (several gauss). Therefore, when the ball IC is installed in the magnetized vehicle, the output due to the magnetization of the vehicle is added as an offset to the output due to the magnetic field strength that should be detected by the ball IC. However, since this offset output differs depending on the type of vehicle and the mounting position of the hole IC on the vehicle, there is a problem that it takes time to correct the offset output.

[0007]

In order to solve such a problem, for example, Japanese Patent Application Laid-Open No. Hei 8-201006 discloses a vehicle position detecting device using a plurality of pickup coils as shown in FIG. Proposed. This vehicle position detecting device is arranged at equal intervals in the traveling direction at the center of the traveling lane, and includes a plurality of permanent magnets (lane marker) M magnetized in a direction perpendicular to the road surface of the traveling lane. A plurality of pickup coils PU arranged in an array in the vehicle width direction below the vehicle and a maximum output voltage of the plurality of pickup coils PU to detect a temporal change amount of the magnetic field strength of And a lateral position detection circuit DET for setting the position of the pickup coil that generates the maximum output voltage in the lateral direction of the vehicle, and detects the lateral position of the vehicle from the position of the pickup coil PU that generates the maximum output voltage. Things.

According to this proposal, a plurality of pickup coils PU detect a temporal change in the magnetic field strength, and among them, the position of the pickup coil that generates the maximum output voltage is set as the lateral position of the vehicle, thereby obtaining the vehicle. This makes it possible to detect the position of the vehicle without being affected by magnetization or geomagnetism.

However, in this vehicle position detecting device, when the vehicle stops or the running speed of the vehicle decreases, the amount of temporal change in the magnetic field strength of the lane marker M is detected by the pickup coil PU. Therefore, there is a problem that the detection accuracy of the lateral position of the vehicle is reduced.

In addition, the apparatus detects the pickup coil PU that generates the maximum output voltage among the plurality of pickup coils PU. Therefore, in order to improve the detection accuracy of the lateral position of the vehicle, the distance between the pickup coils is increased. Need to be narrower. However, if the interval is reduced, the magnetic effect from the lane marker M affects the plurality of pickup coils PU, so that the resolution of each pickup coil PU is reduced and the lateral direction of the vehicle is reduced. Improvement in position detection accuracy cannot be expected. Conversely, if the distance between the pickup coils is widened, the resolution of each pickup coil PU will be high, but the amount of lateral shift of the vehicle based on the detection result will be rough, and the improvement of position accuracy is expected. There is a problem that can not be.

Therefore, an object of the present invention is to provide a vehicle position detecting device and a position detecting method which can improve the detection accuracy of the lateral position of a vehicle without using more detection sensors than necessary. is there.

[0012]

SUMMARY OF THE INVENTION Accordingly, the present invention provides a vehicle position detecting device for detecting a position of a vehicle in a lateral direction with respect to a center of a traveling lane, in order to achieve the above object. Arranged at equal intervals in the horizontal direction from the center,
And a sensor including a plurality of two-axis sensors for detecting the intensity in the X and Z-axis directions of the electromagnetic field generated by the lane markers arranged at predetermined intervals in the center of the running lane in the running direction. Department and
An arithmetic unit for calculating the positional relationship between the lane marker and the two-axis sensor located at the center of the vehicle by performing arithmetic processing based on the output signal from the sensor unit. I do.

A second aspect of the present invention is a vehicle position detecting device for detecting a position of a vehicle in a lateral direction with respect to a center of a traveling lane. A plurality of two-axis sensors for detecting the intensity in the X and Z-axis directions of the electromagnetic field generated by the lane markers disposed at predetermined intervals in the center of the traveling lane in the traveling direction The sensor section includes a sensor section, a vehicle height sensor for detecting the installation height of the two-axis type sensor from the road surface in the sensor section, and an arithmetic processing based on output signals from the sensor section and the vehicle height sensor, thereby providing a rammer. An arithmetic unit for calculating the distance between the car and the two-axis sensor located at the center of the vehicle or the shift direction of the vehicle.

According to a third aspect of the present invention, the sensor unit comprises at least a two-axis sensor, and X,
According to a fourth aspect of the present invention, the two-axis type sensor includes a coil, a housing, and a phase detection circuit for phase-detecting a detection signal related to the Z-axis.
And two detecting elements such as a magnetic element and a magnetoresistive element are arranged so as to cross each other in the X and Z axis directions.

According to a fifth aspect of the present invention, the strength of an electromagnetic field generated by lane markers arranged at predetermined intervals in the traveling direction at the center of the traveling lane is determined by the center of the vehicle. Detected by a plurality of biaxial sensors arranged at substantially equal intervals in the horizontal direction from the portion, compared the magnitude relationship of signal data corresponding to each detected signal, and output the largest detected signal. A vehicle position detecting method for determining a lateral shift direction of a vehicle by calculating a positional relationship between a shaft-type sensor and a two-axis sensor located at a central portion of the vehicle. The present invention compares the magnitude of signal data corresponding to the detection signals of the plurality of biaxial sensors, and compares the comparison result with the detection signals of the preset biaxial sensors. Compare with various setting conditions based on the magnitude relationship of signal data. By detecting the appropriate setting condition by, and outputs the shift amount determined for each setting condition.

According to a seventh aspect of the present invention, the strength of the electromagnetic field generated by the lane markers arranged at predetermined intervals in the traveling direction at the center of the traveling lane is determined by the center of the vehicle. By detecting a plurality of biaxial sensors arranged at substantially equal intervals in the horizontal direction from the portion and calculating the azimuth angle at which the lane marker is located from the biaxial azimuth vector based on this detection signal. ,
A vehicle position detection method is characterized in that a shift direction of the vehicle in a lateral direction is determined, and an eighth invention is based on a detection signal of a specific two-axis sensor among the plurality of two-axis sensors. The azimuth at which the lane marker is located is calculated from the two-axis azimuth vector, and based on the azimuth and the installation height data from the road surface of the specific two-axis sensor output from the vehicle height sensor. Thus, the distance between a specific two-axis sensor and the lane marker is calculated as a shift amount.

Further, a ninth invention of the present invention provides a driving train
The intensity of the electromagnetic field generated by the lane markers arranged at a predetermined interval in the center running direction of the vehicle is controlled by a plurality of two-axis types arranged at substantially equal intervals in the lateral direction from the center of the vehicle. Sensor, and detects a specific two 2
The azimuth at which the lane marker is located is calculated from the azimuth vectors of the two axes based on the detection signals of the axial sensors, and the magnitude of the azimuth of the two biaxial sensors with respect to the lane marker is determined. A vehicle position detecting method is characterized in that a lateral shift direction of the vehicle is determined by comparison.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of a vehicle position detecting device according to the present invention will be described with reference to FIGS. The vehicle position detecting device includes, for example, a sensor unit 1 including a plurality of unit sensor units 1a to 1e, a switching unit 11 such as a multiplexer for appropriately selecting and switching output signals from the unit sensor units 1a to 1e, and a switching unit. An A / D converter 12 for converting the output signal of the A / D converter 11 from an analog value to a digital value; an arithmetic unit 13 such as a CPU for taking in the output signal of the A / D converter 12 and performing various arithmetic processes; The vehicle height sensor 14 detects the installation height of the shaft type sensor from the road surface.

In the above-mentioned sensor section 1, the plurality of unit sensor sections 1a to 1e are configured substantially identically, and each has a flux gate type biaxial sensor A to E configured substantially identically. It has been incorporated. This unit sensor section 1a is, for example, a flux gate type two-axis sensor formed by winding a drive coil around an annular core and winding a first coil 2 and a second coil 3 orthogonally. A; an oscillator 4; a frequency divider 5 for dividing the oscillation frequency of the oscillator 4 to a desired frequency;
And phase detectors 6X and 6Z for phase detection of the detection signal of the second coil 3, integration circuits 7X and 7Z for integrating output signals of the phase detectors 6X and 6Z, and amplification of output signals of the integration circuits 7X and 7Z. DC amplification circuits 8X and 8Z, a stabilized power supply 9, and a reference voltage generation circuit 10. The reference voltage Vref is in the X-axis direction (horizontal direction with respect to the road surface = lateral direction of the vehicle VH). A detection voltage Vx corresponding to the strength of the magnetic field and a detection voltage Vz corresponding to the strength of the magnetic field in the Z-axis direction (perpendicular to the road surface) are output.

The plurality of two-axis sensors A to E are connected to the vehicle V
H at a position which can respond to a magnetic field generated by a lane marker M composed of permanent magnets disposed at predetermined intervals in the center of the traveling lane at substantially constant intervals in the vehicle width direction. When the number of the two-axis sensors is, for example, five, the two-axis sensors C are arranged so as to be located substantially at the center of the vehicle VH. Specifically, the first coil 2 in the biaxial sensors A to E is provided with a second coil 2 so that the magnetic field in the X-axis direction can be detected from the magnetic field generated by the lane marker M. The coil 3 is arranged so that the strength of the magnetic field in the Z-axis direction can be detected. Hereinafter, the first coil 2 of the biaxial sensor A
The detection signal A _X but for detecting the detection signal the second coil 3 is detected and Az, 2-axis type sensor B, C, D, respectively, each of the detection signals E Bx, Bz, Cx, Cz,
Used as Dx, Dz, Ex, Ez.

Next, a vehicle position detecting method using the vehicle position detecting device will be described with reference to FIGS. First, as shown in FIG. 1, prior to traveling of the vehicle VH, a high frequency voltage of, for example, about 100 KHz, about 8 V is applied to the drive coils of the two-axis sensors A to E from the frequency divider 5. The two-axis sensors A to E can also detect the strength of the magnetic field when the magnetic field viewed from the vehicle is either a static magnetic field or a dynamic magnetic field. When the vehicle VH travels in the traveling lane in a certain direction, the appropriate two-axis sensors A to E react to the magnetic field generated by the lane marker M. A detection signal corresponding to the strength of the magnetic field in the direction and the Z-axis direction is output. These detection signals are phase-detected by the phase detection circuits 6X and 6Z, integrated by the integration circuits 7X and 7Z, and amplified by the DC amplification circuits 8X and 8Z. The detection voltages Vx and Vz together with the reference voltage Vref are obtained. Is output. These signals are appropriately selected and switched by the switching unit 11, and are converted from analog values to digital values by the A / D conversion unit 12.

In FIG. 3, in step S1, the A / D conversion data in the A / D conversion unit 12 is read into the calculation unit 13, and in step S2, the read data is converted into a magnetic force value. In step S3, the presence / absence of a response of the two-axis sensors A to E to the lane marker M is determined by using a threshold value. In step S4, the output values of the two-axis sensors A to E with respect to the reference voltage Vref are corrected. In step S5, 2
Among the output values of the axis sensors A to E, it is determined which of the two axis sensors outputs the maximum output, and the process proceeds to step S6. In step S6, it is determined whether or not the two-axis sensors AE respond to the lane marker M in excess of the above-described threshold. If it is determined that all of the two-axis sensors A to E are not responding, the process proceeds to step S7.
The average value of the detection outputs equal to or less than the threshold value detected by the axial sensors A to E is calculated as a correction value of the disturbance (magnetic field from other than the lane marker M), and in step S1, the next reading data is calculated. The data is read into the arithmetic unit 13 as correction data.
On the other hand, if it is determined in step S6 that any of the two-axis sensors AE has a response, the process proceeds to step S8. In step S8, various types of arithmetic processing are performed, and the output is output as a control output to a steering control system in step S9.

The above arithmetic processing is performed, for example, as shown in FIG. First, in step SA1, the lane marker
It is determined whether the north pole of M is located on the road surface side or the south pole is located on the road surface side. At step SA2, azimuth correction is performed. This azimuth correction is performed by the two-axis sensors A to
E performs so-called disturbance correction in response to a magnetic field from a source other than the lane marker M. In step SA3, the two-axis sensor C and the lane marker M disposed at the center are arranged.
Is calculated, and the shift direction of the vehicle in the lateral direction is calculated. In step SA4, the actual shift amount is calculated based on the lateral shift direction of the vehicle calculated from the positional relationship between the two-axis sensor C and the lane marker M. This output is output to the steering control system, so that the position of the vehicle VH is always controlled at the center of the traveling lane.

The specific methods of azimuth correction, shift direction calculation, and lateral position calculation in the above-described arithmetic processing will be sequentially described. First, for azimuth correction, for example, the methods shown in FIGS. 5 and 6 are recommended. In FIG. 5, three biaxial sensors A, B, and C are reacting to the lane marker M.
The two biaxial sensors D and E respond to magnetic fields other than the lane marker M, and their directions are indicated by arrows. Therefore, it is determined that the detection outputs of the two two-axis sensors D and E are caused by disturbance, and the average values of the X-axis component and the Z-axis component are respectively determined by the detection outputs of the three two-axis sensors A, B, and C. The correction is performed by removing (subtracting) from the respective X-axis and Z-axis components. The azimuth θ is
θ = tan ^-1 (Hz / Hx).
Here, Hx and Hz are the detected magnetic field strengths in the X-axis and Z-axis directions, respectively, where Hx = Vx-Vref and Hz = Vz-
Vref. The correction method shown in FIG.
Is located between the lane markers M and M (section a), all the biaxial sensors AE stop responding to the magnetic field of the lane marker M. 2 in a
This is performed by judging that the detection outputs from the axial sensors A to E are caused by disturbance, and removing the detection outputs from the detection outputs of the two-axis sensors responding to the lane marker M. In particular, this correction data is taken into the arithmetic unit 13 and the next b
In the section, when the two-axis sensors A to E react to the lane marker M, they are removed from the X-axis component and the Z-axis component of the detection output.

For the calculation of the shift direction, see FIG.
7 to 8, FIG. 9 to FIG. 10, and FIG.
A method is recommended. The first method shown in FIG.
Out of the detection outputs of the sensors A to E, the detection output (magnetic
Vector value corresponding to the strength of the field) A_Z~ E_ZRelationship
Are converted into a condition pattern of NO1 to NO10, and the condition pattern is
2-axis type sensor for lane marker M by turn
The actual position of C is determined, and the shift direction is uniquely determined.
It is what is done. Condition pattern and shift direction shown in FIG.
Will be described with reference to FIG. For example Article
When the pattern is NO1, detection of the two-axis sensor A
Output A_ZIs the detection output B of the biaxial sensors B to E_Z~ E_ZYo
The lane marker M is a two-axis sensor A
Is located at the position closest to. Therefore, medium
The shift direction of the biaxial sensor C located at the center is indicated by an arrow.
X direction shown (left direction). If the condition pattern is NO3
In the case, the detection output B of the biaxial sensor B_ZIs a 2-axis sensor
A, detection output A of CE _Z, C_Z~ E_ZGreater than
Therefore, the lane marker M is closest to the two-axis sensor B.
Position. Therefore, a two-axis sensor
The shift direction of C is the X direction (left direction) indicated by the arrow.
If the condition pattern is NO5, the biaxial sensor C
Detection output C_ZAre the detection outputs of the two-axis sensors AB and DE.
Force A_Z~ B_Z, D_Z~ E_ZBecause it is bigger,
Marker M is located at the appropriate position closest to biaxial sensor C
You are doing. Therefore, no shift is required. Sa
In addition, when the condition pattern is NO8, a two-axis sensor
D, E detection output D_Z, E_ZAre almost equal, and the two-axis type
Detection output A of sensors A to C_Z~ C_ZGreater than
The lane marker M is a two-axis sensor D and a two-axis sensor.
E. Therefore, the 2-axis type
The shift direction of the sensor C is in the -X direction (right direction) indicated by an arrow.
Become.

The second calculation of the shift direction shown in FIGS.
Is a method in which any of the two-axis sensors BD is laser
When the sensor responds to the marker M, the azimuth of the responding biaxial sensor with respect to the marker M is nine.
The shift direction is determined depending on whether the shift direction is larger than 0 °. For example, as shown by a solid line in FIG.
When the lane marker M is located immediately below the axial sensor C, the azimuth angle θ _C is 90 °, so that no shift is performed. However, when the lane marker M is at the position shown by the dotted line in the figure, the azimuth angle θ _C is smaller than 90 °, so that the shift direction of the biaxial sensor C is the X direction (left direction) indicated by the arrow. )become. Although not shown, when the lane marker M is located on the two-axis sensor D, E side, the azimuth angle θ _C
Is greater than 90 °, so its shift direction is −
It becomes the X direction (right direction). The above azimuth θ _C is given by θ _C =
It is obtained by tan ^-1 (Cz / Cx). Where Cx, C
z is the detection output (vector value corresponding to the strength of the magnetic field) of the X-axis and Z-axis components, respectively. When only the biaxial sensor A or the biaxial sensor E responds to the lane marker M, the shift direction of the biaxial sensor C is the X direction or the -X direction.

The third method of calculating the shift direction shown in FIGS. 11 to 12 is based on the assumption that the two-axis sensors B to D are responding to the lane marker M and the two-axis sensors B and Azimuth θ _BB (= 1) with respect to the lane marker M of the biaxial sensor D
80- [theta] _B ) and the azimuth angle [theta] _D to determine the shift direction of the two-axis sensor C located at the central portion. For example, as shown by a solid line in FIG. 12, when the lane marker M is located at a position slightly shifted from the biaxial sensor C to the biaxial sensor B side, the biaxial sensor B
X is the azimuth angle theta _BB indicating which is larger than the azimuth angle theta _D biaxial sensor D, the shift direction of the two-axis type sensor C by arrows
Direction (left direction). In addition, as shown by the dotted line in FIG.
If the azimuth angle θ _D of the biaxial sensor B is present at a position shifted toward the axial sensor D, the azimuthal angle θ _{BB of the} biaxial sensor D is
Because of being larger, the shift direction of the two-axis sensor C is in the −X direction (right direction) indicated by the dotted arrow. These azimuths θ _BB and θ _D are given by θ _BB = tan ⁻¹ (Bz / Bx), θ
_D = tan ^-1 (Dz / Dx). However, Bx
, Dx, Bz, and Dz are detection outputs (vector values corresponding to the strength of the magnetic field) of the X-axis and Z-axis components, respectively. still,
When only the two-axis sensor A or the two-axis sensor E responds to the lane marker M, the shift direction of the two-axis sensor C is the X direction or the -X direction.

The horizontal position is calculated, for example, by referring to FIG.
~ The three methods shown in Fig. 14, Fig. 15, and Fig. 16 are recommended.
You. A first method shown in FIG.
Among the detection outputs, the detection output of the Z-axis component (depending on the strength of the magnetic field)
Corresponding vector value) A_Z~ E _ZNO1-N
The condition pattern of O10 is converted, and the condition pattern
Actual position of the biaxial sensor C with respect to the lane marker M
Is determined, and a specific shift amount in the lateral direction is determined.
Things. The shift amount is, for example, a two-axis type sensor.
If the arrangement interval between them is set to 200 mm
Under the above conditions, each condition pattern is set as shown in FIG.
Is defined. + And-of the shift amount indicate the shift direction.
+ Indicates a left direction and-indicates a right direction. FIG.
Of the condition pattern and the shift amount (and shift direction)
The relationship will be described with reference to FIG. For example, conditions
When the pattern is NO1, the detection output of the biaxial sensor A
Force A_ZIs the detection output B of the biaxial sensors B to E_Z~ E_ZThan
Because of its large size, the lane marker M is used as a two-axis sensor A.
It will be located at the closest position. Therefore, the center
The direction of shift of the two-axis sensor C located at the position is indicated by an arrow.
X direction (left direction), and the shift amount is almost +40.
0 mm. When the condition pattern is NO3, two axes
Output B of type sensor B_ZAre two-axis sensors A, CE
Detection output A_Z, C_Z~ E_ZBecause it is bigger,
The marker M is located closest to the two-axis sensor B.
Will be. Therefore, the shift direction of the two-axis sensor C
Is the X direction (left direction) indicated by the arrow, and the shift amount is
It is almost +200 mm. If the condition pattern is NO5
In the case, the detection output C of the two-axis sensor C_ZIs a 2-axis sensor
A to B, D to E detection output A_Z~ B_Z, D_Z~ E_ZYo
The lane marker M is a two-axis sensor C
Is located at the appropriate position closest to Follow
Thus, no shift is required. Further, if the condition pattern is NO
8, the detection output D of the two-axis sensors D and E_Z, E
_ZAnd the detection outputs A of the two-axis sensors A to C
_Z~ C_ZBecause it is larger, the lane marker M has two axes
Is located between the type sensor D and the two-axis type sensor E
become. Therefore, the shift direction of the biaxial sensor C is indicated by an arrow.
In the -X direction (right direction), and the shift amount is approximately-
It becomes 300 mm.

The second method of calculating the horizontal position shown in FIG.
For example, among the detection outputs of the two-axis sensors AE, the detection output of the Z-axis component (vector value corresponding to the strength of the magnetic field) _AZ to
The largest _EZ is detected, and the distance L between the biaxial sensor having the maximum output and the lane marker M is calculated.
Then, the shift amount in the lateral position direction is calculated by adding the distance a from the two-axis sensor C located at the center. For example, when the biaxial sensor having the maximum output is the biaxial sensor B, first, the azimuth θ _B of the biaxial sensor B with respect to the lane marker M is given by θ _B = tan ⁻¹ (Bz / B)
x). Using the height data (height h) of the two-axis sensor B from the road surface output from the vehicle height sensor 14, the two-axis sensor B and the lane marker M are used.
Is obtained from L = h / tan θ _B. Therefore, the distance from the biaxial sensor C to the lane marker M is a + L (= 200 mm + L) since the set distance between the biaxial sensors is a, and the shift direction of the biaxial sensor C is as follows. Is the X direction (left direction) indicated by the arrow, and the shift amount is 200 mm + L. still,
Although not shown, the lane marker M is a two-axis sensor B
When the sensor is located between the biaxial sensor C and the biaxial sensor C, the distance L between the biaxial sensor B and the lane marker M is L = h / t.
calculated in _{an (180-θ B),} 2 -axis type sensor C a fit - comma - mosquito distance to -M is a-L (= 200m
m−L). Accordingly, the shift direction is the -X direction (right direction), and the shift amount is 200 mm-L.
become.

The third method of calculating the horizontal position shown in FIG.
For example, among the detection outputs of the two-axis sensors AE, the detection output of the Z-axis component (vector value corresponding to the strength of the magnetic field) _AZ to
Detect the largest _EZ and the next largest _EZ ,
The distance from each biaxial sensor to the lane marker M is calculated, and half of the difference is calculated as the distance from the biaxial sensor on the side with the larger detection output to the lane marker M. shift amount in the lateral direction is calculated by adding the L _1. The two-axis sensor a fit - comma - if the distance L ₁ to the month -M is, for example, following 50mm is not performed the adjustment of the difference. For example, a two-axis sensor having the maximum output is a two-axis sensor C
In the case of (1), first, the azimuth (180-θ _C ) of the two-axis sensor C with respect to the lane marker M is expressed by (180-θ _C ) = t
It is calculated by an ^-1 (Cz / Cx). Then, using the height data (height h) of the two-axis type sensor C from the road surface output from the vehicle height sensor 14, the two-axis type sensor C and the lane marker M are moved horizontally. The distance L ₁ in the direction is L ₁ = h
/ Tan (180−θ _C ). Therefore, when the distance L _1> 0, the shift amount _{(a-L 1/2)} +
Is calculated from _{L 1 = (200mm-L 1} /2) + L 1, in the case of the distance L ₁ <0 is conveniently shift amount is set in advance 50 mm. Note that the shift direction of the biaxial sensor C is the X direction (left direction) when the lane marker M is located to the left of the biaxial sensor C, and the lane marker is shifted. When M is located to the right of the two-axis sensor C, it is in the -X direction (right direction). When only the two-axis sensor C is responding to the lane marker M, the shift amount is 0, and only the two-axis sensor B or the two-axis sensor D is the lane marker. When responding to M, the shift amounts are each 200 mm.

According to this embodiment, the flux gate type two-axis sensors A to E are arranged in the vehicle width direction below the vehicle VH.
Are arranged at substantially constant intervals so as to be able to respond to the magnetic field from the lane marker M. Therefore, regardless of the traveling speed of the vehicle VH, even when the vehicle is running or when the vehicle is at a standstill, the lane marker can be controlled. The intensity of the magnetic field generated by the car M can be detected. Therefore,
Based on the detection data corresponding to the magnetic field strength in the X-axis and Z-axis directions of the two-axis sensors AE, the vehicle VH
Can detect the actual position with respect to the lane marker M.
The shift direction or shift amount can be accurately calculated.

For example, in calculating the shift direction of the vehicle VH, the first method is to compare the magnitude of detection data corresponding to the strength of the magnetic field in the Z-axis direction of the two-axis sensors A to E, and to determine the maximum output. This is to determine the positional relationship between the two-axis type sensor C and the two-axis type sensor C located at the center of the vehicle, and determine the shift direction of the vehicle to the left or right. In addition, the process of calculating the shift direction can be simplified. In particular, when it is necessary to calculate a specific shift amount, the distance from the two-axis sensor C located at the center to the two-axis sensor having the maximum output is set between the two-axis sensors set in advance. The calculation may be based on the distance, and the calculation of the shift amount can be simplified.

In calculating the shift direction of the vehicle VH, the second
Is to calculate the azimuth angle of a specific two-axis type sensor among the two-axis type sensors responding to the lane marker M with respect to the lane marker M, and calculate the magnitude of the azimuth angle. Calculation processing using two-axis vector data from an arbitrary two-axis sensor among the two-axis sensors that are responding because the shift direction of the vehicle is determined to the left or right, for example. , The shift direction can be calculated. For example, a shift direction is calculated using detection data from a plurality of biaxial sensors,
If the determination is made comprehensively, a more accurate shift direction can be calculated. In particular, when it is necessary to calculate a specific shift amount, the two-axis sensor used for calculating the azimuth angle and the ranma based on the azimuth angle and the height h of the two-axis sensor from the road surface are used. Calculate the distance to the car M,
Furthermore, the distance from the two-axis sensor to the two-axis sensor C located at the center may be added, and the shift amount can be easily calculated.

In calculating the shift direction of the vehicle VH, the third
The method of (1) is such that, of the two-axis type sensors that are responding to the lane marker M, the lane markers of the two two-axis type sensors having a positional relationship sandwiching the lane marker M are provided. -Compute the azimuth angle with respect to the second method because the azimuth angle with respect to M is calculated and the shift direction of the vehicle is determined to be a left direction or a right direction depending on whether a subtraction value of these azimuth angles is greater than 0 or not. As a result, more accurate position detection becomes possible. In particular, when it is necessary to calculate a specific shift amount, the two-axis sensor used for calculating the azimuth angle and the ranma based on the azimuth angle and the height h of the two-axis sensor from the road surface are used. The shift amount can be easily calculated by calculating the distance from the car M and adding the distance from the two-axis sensor to the two-axis sensor C located at the center.

Further, the detection of the lane marker M by the two-axis sensors AE is performed based on the two-axis azimuth vectors (X-axis and Z-axis directions) from the two-axis sensors AE. Therefore, even if the number of biaxial sensors arranged on the vehicle VH is small, position detection can be performed with relatively high accuracy. Therefore,
Not only can the apparatus cost be reduced, but also the characteristic adjustment between the two-axis sensors can be simplified.

In particular, when a detection signal is output in spite of no response of the two-axis sensors A to E to the lane marker M, it is determined that the detection output is due to disturbance.
If the disturbance is corrected by subtracting from the detection output of the two-axis sensor responding to the lane marker M, the accuracy of the shift direction or shift amount calculation result can be further improved.

The present invention is not limited to the above-described embodiment. For example, the biaxial sensor may be arranged so that the first and second coils intersect with each other.
Of the elements and the like, two elements of the same type can be arranged so as to cross each other, the number of arrangements can be set to other than five, and the detection output of the two-axis sensor is A / D conversion may be performed simply through the switching unit and taken into the arithmetic unit. If the installation height of the two-axis sensor from the road surface is fixed, the vehicle height sensor can be omitted.
Further, the disturbance correction can be omitted in some cases. In addition, the respective methods of calculating the shift direction and calculating the lateral position (shift amount) may be independently employed, or may be appropriately combined. Further, the lane marker may be a radio wave transmitter in addition to a permanent magnet for generating a magnetic field. In this case, the two-axis sensor is constituted by a coil or an antenna capable of receiving a radio wave. There is a need.

[0038]

As described above, according to the present invention, a plurality of biaxial sensors are provided in the vehicle width direction so as to be substantially constant so as to be able to respond to the electromagnetic field from the lane marker. Since they are arranged at intervals, the electromagnetic field generated by the lane marker can be detected even when the vehicle is traveling or when the vehicle is stopped, regardless of the traveling speed of the vehicle. Therefore, the actual position of the vehicle relative to the lane marker can be detected by various methods based on the detection data corresponding to the electromagnetic field strengths in the X-axis and Z-axis directions of the plurality of two-axis sensors. The shift direction or shift amount can be accurately calculated.

For example, in calculating the shift direction of the vehicle, the magnitude of the detected data corresponding to the strength of the electromagnetic field in the Z-axis direction of a plurality of two-axis sensors is compared, and the maximum output two-axis sensor is If a method of determining the positional relationship with respect to the two-axis sensor located at the center and determining the shift direction of the vehicle to the left or right is adopted, the shift direction calculation process can be performed. Can be simplified. In particular, when it is necessary to calculate a specific shift amount, the distance from the biaxial sensor located at the center to the biaxial sensor having the maximum output is set to a predetermined distance between the biaxial sensors. , And the calculation of the shift amount can be simplified.

In calculating the shift direction of the vehicle, the
The azimuth angle of a specific two-axis type sensor among the two-axis type sensors responding to the marker is calculated with respect to the lane marker, and the shift direction of the vehicle is shifted leftward according to the magnitude of the azimuth angle. Alternatively, by adopting a method of determining the shift direction to the right, the shift direction can be calculated by arithmetic processing using biaxial vector data from an arbitrary biaxial sensor among the biaxial sensors that are responding. In particular, when it is necessary to calculate a specific shift amount, the two-axis sensor used for calculating the azimuth and the lane marker are used based on the azimuth and the height of the two-axis sensor from the road surface. The shift amount can be easily calculated by calculating the distance between the two-axis sensor and the distance from this two-axis sensor to the two-axis sensor located at the center.

In calculating the shift direction of the vehicle, the
The azimuth angle of the two biaxial sensors having a positional relationship sandwiching the rammer car among the biaxial sensors reacting to the rammer car with respect to the rammer car is calculated, If a method of determining the shift direction of the vehicle to the left or right based on whether or not the subtraction value of these azimuth angles is greater than 0 is employed, more accurate position detection is possible. In particular,
If it is necessary to calculate a specific shift amount, the two-axis sensor used for calculating the azimuth and the lane marker are used based on the azimuth and the height of the two-axis sensor from the road surface. Is calculated, and the distance from the two-axis sensor to the two-axis sensor located at the center portion may be added, so that the shift amount can be easily calculated.

Furthermore, a rammer with a two-axis sensor
Since the detection of the car is performed based on the azimuth vectors of the two axes from the two-axis sensor, the position can be detected relatively accurately even if the number of the two-axis sensors arranged in the vehicle is small. . Therefore, not only can the equipment cost be reduced,
Characteristic adjustment between the two-axis sensors can be easily performed.

[Brief description of the drawings]

FIG. 1 is a diagram showing one embodiment of a vehicle position detecting device according to the present invention, wherein FIG. 1 (a) is a block circuit diagram, and FIG. 1 (b) is a block diagram of a unit sensor unit shown in FIG. 1 (a). FIG.

FIG. 2 is a view for explaining an installation state of a two-axis sensor applied to the vehicle position detecting device shown in FIG. 1, and FIG.
1B is a front view, and FIG. 2B is a plan view of FIG.

FIG. 3 is a flowchart for explaining a vehicle position detecting method by the vehicle position detecting device according to the present invention.

FIG. 4 is a flowchart of the arithmetic processing shown in FIG. 3;

FIG. 5 is a schematic diagram for explaining a first correction method of the azimuth correction shown in FIG. 4;

FIG. 6 is a schematic diagram for explaining a second correction method of the azimuth correction shown in FIG. 4;

FIG. 7 is a condition pattern diagram for explaining a first calculation method of shift direction calculation shown in FIG.

FIG. 8 is an explanatory diagram of the condition pattern diagram shown in FIG. 7;

9 is a condition pattern diagram for explaining a second calculation method for calculating the shift direction shown in FIG.

FIG. 10 is an explanatory diagram of the condition pattern diagram shown in FIG. 9;

FIG. 11 is a condition pattern diagram for explaining a third calculation method for calculating the shift direction shown in FIG. 4;

FIG. 12 is an explanatory diagram of the condition pattern diagram shown in FIG. 11;

FIG. 13 is a condition pattern diagram for explaining a first calculation method of calculating the horizontal position shown in FIG. 4;

FIG. 14 is an explanatory diagram of the condition pattern diagram shown in FIG. 13;

FIG. 15 is a schematic diagram for explaining a second calculation method for calculating the horizontal position shown in FIG. 4;

FIG. 16 is a schematic diagram for explaining a third calculation method for calculating the horizontal position shown in FIG. 4;

FIG. 17 is a circuit block diagram of a conventional vehicle position detecting device.

[Explanation of symbols]

 A to E 2-axis type sensor M Rainmer car VH Vehicle 1 Sensor unit 1a to 1e Unit sensor unit 2 First coil 3 Second coil 4 Oscillator 5 Frequency divider 6x, 6z Phase detector 7x, 7z Integrator 8x, 8z DC amplifier 9 Stabilized power supply 10 Reference voltage 11 Switching unit 12 A / D converter 13 Operation unit 14 Vehicle height sensor

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Kazunori Suzuki 1-4-4 Shiromi, Chuo-ku, Osaka-shi, Osaka Japan Home Electronics Co., Ltd. (56) References JP-A-9-229690 (JP, A JP-A-9-269231 (JP, A) JP-A-11-23209 (JP, A) JP-A-3-17806 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G08G 1/042 G01B 7/00 G01C 21/00 G05D 1/02

Claims (2)

(57) [Claims] 1. A predetermined distance in a traveling direction at the center of a traveling lane.
Of electromagnetic field generated by lane markers arranged at intervals
Are arranged at substantially equal intervals laterally from the center of the vehicle.
Detected by a plurality of biaxial sensors, and based on this detection signal,
The direction of the lane marker from the two-axis azimuth vector
By calculating the position angle, the method of shifting the vehicle in the lateral direction
Determine the directionToVehicle position detection methodAnd  Of the plurality of biaxial sensors, a specific biaxial sensor
Lane marker from two-axis direction vector based on detection signal
The azimuth where the vehicle is located is calculated, and the azimuth and
Installation of a specific two-axis sensor output from the road from the road surface
Specific biaxial sensors and lanemers based on height data
The distance to the car is calculated as the shift amount.
ToVehicle position detection method. 2. The method according to claim 1, wherein the intensity of the electromagnetic field generated by the lane markers arranged at predetermined intervals in the traveling direction at the center of the traveling lane is reduced by a plurality of two-dimensionally arranged laterally from the center of the vehicle. The azimuth at which the lane marker is located is calculated from the azimuth vectors of two axes based on the detection signals of two specific two-axis sensors among the plurality of two-axis sensors. A vehicle position detection method comprising: determining a shift direction of a vehicle in a lateral direction by comparing magnitudes of azimuths of two biaxial sensors with respect to a lane marker.