JPH1083499A - Vehicle position/direction angle detection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To precisely detect a position and a direction angle by estimating the position of a vehicle based on the detection output of a marker arranged on a road and estimating and detecting a yaw angle based on shift track data of the vehicle, which is estimated through the use of position history data formed, based on position data. SOLUTION: A vehicle position estimation part 10 estimates the position of the vehicle against the array of the road marker, based on the detection output of a road marker sensor 6 for detecting the road marker arranged on the road, and obtains vehicle position data. A vehicle position data memory 11 preserves vehicle position data and obtains position history data of the vehicle. A vehicle track estimation part 12 estimates the shift track of the vehicle on the road by using the position history data and obtains vehicle track data. A yaw angle estimation part 13 estimates/detects the yaw angle of the vehicle, based on vehicle track data and obtains vehicle direction angle data. Thus, detection can precisely be executed without raising cost even if the vehicle travels comparatively for a long time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses a marker arranged on a road on which a vehicle travels, and the position of the vehicle on the road with respect to the marker arrangement and the front-back direction of the vehicle are defined with respect to the marker arrangement direction. The present invention relates to a vehicle position and direction angle detecting device for detecting a direction angle.

[0002]

2. Description of the Related Art In order to utilize a vehicle as a safe, comfortable and efficient means of transportation, a wide range of technologies including advanced technologies in the fields of information communication and information processing are used to determine the vehicle and the road on which the vehicle travels. ITS (Intell.), An intelligent transportation system that integrates
igent Transport System) has been proposed. And
As part of the attempt to realize such ITS,
The Automated Highway System (Autmated Highway Syst.) Is mainly intended to allow vehicles running on the highway to enter an autonomous driving state with sufficient safety secured.
em: AHS) is being considered.

In an automatic driving highway system, for example, road markers are arranged on a road on which a vehicle travels, and a road marker is arranged on a vehicle traveling on a road on which the road markers are arranged. Includes a road surface marker sensor fixed to the vehicle, and a device that detects a position of the vehicle with respect to an array of road surface markers on the road based on a detection output obtained from the road surface marker sensor. Can be Each of the road surface markers
For example, it is a magnetic marker called a magnetic nail that forms a magnetic field, and is arranged along the traveling lane at the center in the width direction of the traveling lane formed on the road surface. Also,
The road marker sensor fixed to the vehicle is, for example, a magnetic sensor, responds to a magnetic field formed by each magnetic marker as the vehicle travels, and outputs a detection output of the magnetic marker obtained by each magnetic marker. From the vehicle to the road marker sensor in accordance with the distance in the width direction of the vehicle.

With respect to an apparatus including a road surface marker sensor provided in a vehicle, when the vehicle travels on a traveling lane formed on the road surface, the position of the vehicle with respect to the detected array of road surface markers is determined by the vehicle position. Indicates that the vehicle departs from the driving lane, indicating that the vehicle is separated from the vehicle by a predetermined distance or more, and performs a warning operation, for example, to make the driver of the vehicle recognize the fact. It is thought that it is provided with. The warning operation is performed, for example, by issuing a warning.

[0005] For example, a warning operation that generates an alarm by a device including a road surface marker sensor provided in such a vehicle is performed not only in accordance with the position of the vehicle with respect to the arrangement of the road surface markers, but also on the road surface. It is desired to be performed in accordance with the position of the vehicle with respect to the arrangement of the markers and the direction angle (the yaw angle of the vehicle) formed by the longitudinal direction of the vehicle with respect to the arrangement direction of the road surface markers. That is, it is desired that a device including a road marker provided in the vehicle detects not only the position of the vehicle with respect to the arrangement of the road markers but also the yaw angle of the vehicle.

More specifically, the position of the vehicle with respect to the arrangement of the road surface markers is determined so that the warning operation by the device including the road surface marker sensor provided on the vehicle is performed more effectively and more accurately. If it indicates that it is more than a predetermined distance from the array of road surface markers,
In accordance with the yaw angle of the vehicle at that time, it is determined whether or not the warning operation should be performed. Further, when the warning operation should be performed, the timing at which the warning operation is to be started or the warning operation is performed. It would be desirable to set the timing to be terminated.

[0007] For example, when a vehicle traveling on a traveling lane has a relatively large yaw angle and its front end is directed to the outside of the traveling lane, such a situation occurs. The fact that the warning operation is started at an earlier timing than in the case where the vehicle does not exist contributes to an improvement in certainty in preventing a situation where the vehicle deviates from the traveling lane.

[0008]

However, in a device including a road marker sensor provided in a vehicle as described above, which has been conventionally proposed, a road surface marker is detected based on a detection output obtained from the road marker sensor. Although the position of the vehicle with respect to the marker array can be detected, the yaw angle of the vehicle cannot be detected. Therefore, when the vehicle travels on the traveling lane formed on the road surface, the position of the vehicle with respect to the detected arrangement of the road surface markers indicates that the vehicle is separated from the arrangement of the road surface markers by a predetermined distance or more. However, a warning operation performed when a situation in which the vehicle departs from the traveling lane is predicted is performed only in accordance with the position of the vehicle with respect to the array of road surface markers, and a desired warning operation cannot be obtained. .

Therefore, the vehicle is provided with an image pickup means for picking up an image of a front road surface condition and an image processing means for processing an image pickup output obtained from the image pickup means so that the yaw angle of the vehicle can be detected. It is conceivable to provide the vehicle with a yaw rate sensor for detecting a change in the angle and a yaw rate processing means for obtaining the yaw angle of the vehicle in accordance with the detection output obtained from the yaw rate sensor.

However, when the vehicle is provided with the image pickup means and the image processing means to detect the yaw angle of the vehicle, the traveling environment for the vehicle in which the yaw angle of the vehicle is properly detected is varied. There is a problem that the range is limited depending on the conditions, and the cost required for detecting the yaw angle of the vehicle increases. In addition, when the vehicle is provided with a yaw rate sensor and a yaw rate processing unit to detect the yaw angle of the vehicle, unless a very expensive and highly accurate yaw rate sensor is used, a detection error generated in the yaw rate sensor may be reduced. Therefore, when the vehicle travels for a relatively long time, the detected yaw angle of the vehicle gradually increases in the degree of lack of accuracy,
There is an inconvenience that it cannot be put to practical use.

In view of the above, the present invention detects a marker arranged on a road on which a vehicle travels, and detects a position of the vehicle with respect to the marker array based on a detection output obtained thereby. Also, the yaw angle of the vehicle is not dependent on the imaging means and the image processing means or the yaw rate sensor and the yaw rate processing means. Provided is a vehicle position and direction angle detection device that can accurately detect even when traveling for a relatively long time.

[0012]

SUMMARY OF THE INVENTION A vehicle position and direction angle detecting device according to the present invention is provided in a vehicle and detects a marker arranged on a road on which the vehicle travels as the vehicle travels. And vehicle position estimating means for estimating and detecting the position of the vehicle with respect to the marker array based on the detection output obtained from the marker detecting means, and obtaining vehicle position data representing the estimated and detected position of the vehicle. The obtained vehicle position data is stored, and a vehicle position history data forming unit that obtains position history data of the vehicle, and a position history data obtained from the vehicle position history data forming unit are used to determine a movement locus of the vehicle on the road. Vehicle trajectory estimating means for estimating and obtaining vehicle trajectory data representing the estimated trajectory of the vehicle, and vehicle trajectory data obtained from the vehicle trajectory estimating means Based on estimates detects the yaw angle of the vehicle, and includes a vehicle direction angle estimating means for obtaining a vehicle direction angle data representing the yaw angle estimated detected.

[0013] In the vehicle position and direction angle detecting device according to the present invention having the above-described configuration, the vehicle position estimating means detects a marker output arranged on the road on which the vehicle travels based on the detection output. Thus, the position of the vehicle with respect to the marker array is estimated and detected. At the same time, the position history data is formed by the vehicle position history data forming means based on the vehicle position data obtained from the vehicle position estimating means, and the position history data obtained from the vehicle position history data forming means is formed by the vehicle trajectory estimating means. Is used to estimate the trajectory of the vehicle on the road, vehicle trajectory data representing the estimated trajectory of the vehicle is obtained, and the vehicle directional angle estimating unit obtains the vehicle trajectory data obtained from the vehicle trajectory estimating unit. Based on this, the yaw angle of the vehicle is estimated and detected.

Therefore, in the vehicle position and direction angle detecting device according to the present invention, detection is performed by estimating the position of the vehicle with respect to the marker array based on the detection output of the markers arranged on the road on which the vehicle travels. And the detection based on the estimation of the yaw angle of the vehicle does not depend on the imaging means and the image processing means or the yaw rate sensor and the yaw rate processing means. Without inviting, and even when the vehicle travels for a relatively long time, it is performed with high accuracy.

[0015]

FIG. 2 shows a vehicle to which an example of a vehicle position and direction angle detecting device according to the present invention is applied, and a road on which the vehicle travels. A traveling lane 3 is formed on the road shown in FIG. 2, and the vehicle 1 is traveling on the traveling lane 3. An example of the vehicle position and direction angle detection device according to the present invention is applied to the vehicle 1. Have been.

The traveling lane 3 is separated from other portions by intermittent white lines 3R and 3L provided on both sides thereof, and has a straight portion, a curved portion, a bent portion, and the like according to the situation of the entire road. It is growing. A large number of road surface markers 5 are arranged and arranged at predetermined mutual intervals at a central portion in the width direction of the traveling lane 3, that is, a central portion between the intermittent white line 3R and the intermittent white line 3L. Markers 5 form array 5A.

Each of the arranged road markers 5 is, for example, a magnetic marker called a “magnetic nail” that forms a magnetic field. The magnetic field formed by the road surface markers 5 which are magnetic markers has a substantially constant intensity.

In the vehicle 1, for example, each of the road surface markers 5 arranged in the traveling lane 3 at the center in the width direction (lateral direction) at the front portion thereof is detected as the vehicle 1 travels. A road marker sensor 6 is mounted to form marker detection means fixed to the vehicle 1. The road surface marker sensor 6 responds to a magnetic field formed by each road surface marker 5 which is a magnetic marker, for example, and outputs a detection output of the road surface marker 5 obtained thereby from each road surface marker 5 to the road surface marker sensor 6. The information is transmitted as being changed according to the distance of the vehicle 1 in the width direction.

The detection output of the road marker 5 obtained from the road marker sensor 6 is obtained, for example, as a voltage signal. In FIG. 3 (horizontal axis: time), V _n , V _{n + 1,} V
_{n + 2, ·····, -V n} + 6, the as shown as -V n + _7, the reference level "0" corresponding to the arrangement of the road surface marker 5, a positive voltage value Things (V _n ~
V _{n + 4} ), one that takes a reference level “0” (V _{n + 5} ), and one that takes a negative voltage value (−V _{n + 6} , −V _{n + 7} )
It is obtained corresponding to each of the road surface markers 5. Among the detection outputs of the road marker 5 obtained from such a road marker sensor 6, those having a positive voltage value (V _n to V _n )
V _{n + 4} ) is obtained when the road marker sensor 6 is shifted to the side of the intermittent white line 3R (right side) with respect to the road marker 5, and the reference level “0” is obtained (V _{n + 5} ). , Which are obtained when the road marker sensor 6 is located immediately above the road marker 5 and have a negative voltage value (−V _{n + 6} , −V _{n + 7} )
Is obtained when the road marker sensor 6 is at a position shifted to the side of the intermittent white line 3L (left side) with respect to the road marker 5. Then, the positive voltage value taken by each of the detection outputs V _{n to} V _{n + 4} is the vehicle 1 from the road marker 5 to the road marker sensor 6.
, The negative voltage value taken by each of the detection outputs −V _{n + 6} and −V _{n + 7} corresponds to the distance from the road marker 5 to the road marker sensor 6. Up to the intermittent white line 3L in the width direction of the vehicle 1.

FIG. 1 shows an example of a vehicle position and direction angle detecting device according to the present invention applied to the vehicle 1 shown in FIG. The example shown in FIG. 1 includes a road surface marker sensor 6 attached to the center in the width direction (left-right direction) of the front part of the vehicle 1, and the detection shown in FIG. output _{V n ~V n + 4, V} n + 5, -
A detection output SM which is a voltage signal corresponding to the distance in the width direction of the vehicle 1 from the road marker 5 to the road marker sensor 6, which is _{expressed as} Vn _{+ 6} and -Vn _{+ 7} , is transmitted. .

Further, in the example shown in FIG.
And a vehicle state detector 7 for detecting the traveling speed of the vehicle 1 and the like, and a detection output from the vehicle state detector 7 as a voltage signal corresponding to the detected traveling speed of the vehicle 1. SV and other detection outputs (not shown) are sent out. Further, in the example shown in FIG. 1, road curvature data DRC indicating the curvature of the road on which the traveling lane 3 is formed.
And a road structure data transmitting unit 8 for transmitting other data (not shown) relating to the structure of the road, marker interval data DSM indicating the mutual distance between the road surface markers 5 arranged in the traveling lane 3, and other information relating to the arrangement of the markers. A marker arrangement data transmitting unit 9 for transmitting the data (not shown) is provided.

Each of the road structure data transmitting section 8 and the marker arrangement data transmitting section 9 includes, for example, a database device constituted by using an optical disk or the like as a data storage medium, a data transmitting / receiving means installed on a road, and a vehicle. A data transmission / reception device or the like that captures data through road-to-vehicle communication, which is data communication performed between the devices, and transmits the captured data.

The detection output SM obtained from the road marker sensor 6, the road curvature data DRC sent from the road structure data sending unit 8, and the marker interval data DSM sent from the marker arrangement data sending unit 9 are calculated by the vehicle position estimating unit 10. Supplied to The vehicle position estimating unit 10 estimates and detects the position of the vehicle 1 on which the road marker sensor 6 is fixed with respect to the array 5A of the road markers 5 based on the detection output SM, and determines the estimated position of the road marker 5 of the vehicle 1. The operation of obtaining the vehicle position data DPV representing the position with respect to the array 5A is based on the assumption that the estimated position of the road surface marker 5 of the vehicle 1 with respect to the array 5A is corrected by the road curvature data DRC and the marker interval data DSM. Under the condition. Thereby, the vehicle position data DPV obtained from the vehicle position estimating unit 10 is obtained by being estimated and detected based on the detection output SM and corrected by the road curvature data DRC and the marker interval data DSM.
The position of the vehicle 1 with respect to the array 5A of the road surface markers 5 is shown. The position of the vehicle 1 is represented by the array 5 of the road surface markers 5 in the traveling lane 3 which is represented as a straight line in FIG.
A is as shown as PV (open circle) for A.

The vehicle position data DPV obtained from the vehicle position estimating unit 10 is supplied to and stored in the vehicle position data memory 11. Accordingly, the vehicle position data DPV from the vehicle position estimating unit 10 is sequentially stored and stored in the vehicle position data memory 11, and the position history data D for the vehicle 1 traveling on the traveling lane 3 is stored.
PH is formed. Therefore, the vehicle position data memory 11
Is vehicle position data D obtained from the vehicle position estimating unit 10.
Save PV and store position history data DPH for vehicle 1
This means that the vehicle position history data forming means for obtaining the above is formed.

The position history data DPH obtained from the vehicle position data memory 11 is supplied to a vehicle trajectory estimating unit 12. The detection output SV sent from the vehicle state detection unit 7 is also supplied to the vehicle trajectory estimation unit 12. Then, the vehicle trajectory estimating unit 12 uses the position history data DPH from the vehicle position data memory 11 to output the travel lane 3 formed on the road.
The movement locus of the vehicle 1 above is estimated.

In estimating the movement locus of the vehicle 1 using the position history data DPH by the vehicle locus estimating unit 12, the vehicle locus estimating unit 12 includes, for example, a vehicle transmitted from the vehicle state detecting unit 7. 1 with reference to the detection output SV which is a voltage signal corresponding to the traveling speed of the vehicle 1
Is set, the parameters of the complementary curve are determined by matching the complementary curve with the position history data DPH, and the moving trajectory of the vehicle 1 is determined using the complementary curve obtained by determining the parameters. Perform the estimation process. At this time, the setting of the supplementary curve relating to the movement trajectory of the vehicle 1 is performed using, for example, a polynomial curve, and the matching between the supplementary curve and the position history data DPH is performed by a method using the least squares method, A method of minimizing a geometrical distance from the DPH is performed.

The trajectory of the vehicle 1 estimated in this manner is as shown in FIG. 5 as TRA (broken line) with respect to the array 5A of the road surface markers 5 in the traveling lane 3 represented as a straight line. You.

Further, when the vehicle locus estimating unit 12 estimates the moving locus of the vehicle 1 using the position history data DPH, other processes performed by the vehicle locus estimating unit 12 in place of the above-described processes include, for example, A vehicle movement trajectory curve is calculated from a vehicle motion model for the vehicle 1 with reference to the detection output SV, which is a voltage signal corresponding to the traveling speed of the vehicle 1 and transmitted from the vehicle state detection unit 7. Determining the parameters of the vehicle trajectory curve by matching the vehicle trajectory curve with the position history data DPH, and estimating the trajectory of the vehicle 1 using the vehicle trajectory curve obtained by determining the parameters. Is done.

The trajectory of the vehicle 1 on the traveling lane 3 estimated in this manner is shown as a TRB (broken line) with respect to the array 5A of the road surface markers 5 in the traveling lane 3 represented as a straight line in FIG. It is as follows.

Further, the vehicle trajectory estimating section 12 forms vehicle trajectory data DTR representing the movement trajectory of the vehicle 1 on the travel lane 3 estimated as described above, and estimates the vehicle trajectory data DTR as a yaw angle. To the unit 13.

The yaw angle estimating unit 13 includes a vehicle locus estimating unit 12
From the vehicle trajectory data DTR, the angle of the movement trajectory of the vehicle 1 on the travel lane 3 represented by the vehicle trajectory data DTR with respect to the array 5A of the road surface markers 5 in the travel lane 3 is determined. Is estimated and detected. The estimation detection of the yaw angle of the vehicle 1 is performed, for example, by using a movement trajectory of the vehicle 1 represented as a broken line TRA with respect to an array 5A of the road surface markers 5 in the traveling lane 3 represented as a straight line in FIG. For example, the angle formed by the broken line TRA that is the movement locus of the vehicle 1 with respect to the array 5A of the road surface markers 5 as indicated by θ in FIG.

The yaw angle estimating unit 13 generates vehicle direction angle data DYW representing the yaw angle of the vehicle 1 estimated and detected.
And outputs the vehicle direction angle data DYW to the output terminal 1
4 is derived. Accordingly, the yaw angle estimation unit 13 estimates and detects the yaw angle of the vehicle 1 based on the vehicle trajectory data DTR from the vehicle trajectory estimation unit 12, and the vehicle direction angle data DYW representing the estimated and detected yaw angle of the vehicle 1. This means that a vehicle direction angle estimating means for obtaining the following is formed.

The vehicle position data DPV obtained from the vehicle position estimating unit 10 is derived to an output terminal 15. In this way, output terminals 14 and 15 are obtained, respectively.
Vehicle direction angle data DYW indicating the yaw angle of the vehicle 1 and vehicle position data DPV indicating the position of the vehicle 1 with respect to the array 5A of the road surface markers 5 are supplied to the warning unit 16.

Thus, the warning unit 16 determines the position of the vehicle 1 represented by the vehicle position data DPV with respect to the array 5A of the road surface markers 5 and the vehicle 1 represented by the vehicle direction angle data DYW.
For example, the position of the vehicle 1 with respect to the array 5A of the road surface markers 5 indicates that the vehicle 1 is separated from the array 5A of the road surface markers 5 by a predetermined distance or more according to the yaw angle of the vehicle 1. When the yaw angle of the vehicle 1 is relatively large and the front end of the vehicle 1 faces the outside of the traffic lane 3 and the vehicle 1 is expected to deviate from the traffic lane 3, a warning action is issued. Do. Therefore, the warning unit 16 issues a warning, for example, when the detection of the road marker 5 by the road marker sensor 6 is not performed for a predetermined period. Also,
Road surface marker 5 of vehicle 1 represented by vehicle position data DPV
Of the vehicle 1 in accordance with the position of the vehicle 1 in the array 5A and the yaw angle of the vehicle 1 represented by the vehicle direction angle data DYW.
When there is no longer any risk of departure from the warning, the warning operation is stopped.

FIG. 7 shows a specific configuration example of the warning unit 16 shown in FIG. In the specific configuration example shown in FIG.
An alarm signal transmitting unit 20 and an alarm generating unit 21 are provided. The alarm signal transmitting unit 20 stores the vehicle direction angle data DYW representing the yaw angle of the vehicle 1 and the position of the vehicle 1 with respect to the array 5A of the road surface markers 5 obtained at the output terminals 14 and 15 shown in FIG. Representing vehicle position data D
The PV is supplied, and further provided on the vehicle 1 so that the vehicle 1
, And a detection output SV from a vehicle speed detection unit 22 that sends out a detection output SV indicating the detected traveling speed of the vehicle 1 is also supplied.

The alarm signal transmitting section 20 outputs the vehicle position data D
In accordance with the position of the vehicle 1 represented by the PV with respect to the array 5A of the road surface markers 5, the yaw angle of the vehicle 1 represented by the vehicle direction angle data DYW, and the traveling speed of the vehicle 1 represented by the detection output SV, the vehicle 1 moves in the traveling lane 3. When there is a possibility that a lane departure from the vehicle may occur, an alarm signal SAM is sent to the alarm generator 21. The alarm generation unit 21 issues an alarm according to the alarm signal SAM, and thereby urges the driver of the vehicle 1 to perform a steering operation for avoiding the lane departure of the vehicle 1.

At this time, the warning signal transmitting section 20 determines the road marker 5 based on the position of the vehicle 1 with respect to the array 5A of the road marker 5 represented by the vehicle position data DPV.
Is obtained as the lateral displacement of the vehicle 1. Further, in the alarm signal transmitting unit 20, a predetermined value of the lateral displacement is set as an alarm reference as shown by a solid line in FIG. 8 (horizontal axis: time, vertical axis: lateral displacement). It is determined whether the lateral displacement of the vehicle 1 as shown by the following is less than the warning reference or not less than the warning reference.

The setting of the value of the lateral displacement used as an alarm reference is such that when an alarm is issued from the alarm generation unit 21, the driver who has recognized the alarm generally has a lateral displacement of a magnitude proportional to the yaw angle of the vehicle 1. The driver avoids the lane departure of the vehicle 1 by generating an acceleration. For example, Yw is a lateral displacement used as an alarm reference, Y0 is a constant determined according to the width of the traveling lane and the width of the vehicle 1, Td is the reaction time of the driver, Vv is the traveling speed of the vehicle 1, and Vv is the traveling speed of the vehicle 1. The yaw angle (deviation yaw angle) when the front end is directed to the outside of the traveling lane is ψ0, and the vehicle 1 has a lateral yaw angle generated to avoid the lane departure when the vehicle 1 has a deviation yaw angle ψ0. Assuming that the acceleration is G, the value of the lateral displacement used as an alarm reference is set in accordance with the relationship expressed as Tw = Y0− (Td + Vv / 2G) · Vv · ψ0. That is, the setting of the value of the lateral displacement used as the alarm reference for the vehicle 1 depends on the deviation yaw angle of the yaw angle of the vehicle 1 represented by the vehicle direction angle data DYW and the traveling speed of the vehicle 1 represented by the detection output SV. It will be set accordingly.

The constant Y0 is, for example, the width of the traveling lane being 3.
When the vehicle 1 is 1 m and the width of the vehicle 1 is 1.7 m, the value is set to 0.7, and the reaction time Td of the driver is set to 0.41 second by using an experimentally determined value. , The lateral acceleration G is also 1.0 m /
S ² / deg. Under such circumstances, the relationship between the deviated yaw angle (ψ0) and the warning reference (Tw) for the vehicle 1 is indicated by, for example, a solid line in FIG. 9 (horizontal axis: deviated yaw angle, vertical axis: warning reference). It is assumed to be.

When the lateral displacement of the vehicle 1 is less than the alarm reference set as described above, the alarm signal transmitting section 20 does not transmit the alarm signal SAM.
On the other hand, when the lateral displacement of the vehicle 1 is equal to or greater than the alarm reference set as described above, the alarm signal transmitting unit 20 transmits the alarm signal SAM. By doing so, it is possible to prevent a situation in which the warning is issued from the warning generating unit 21 too early and a situation in which the driver of the vehicle 1 delays the steering operation to avoid the lane departure.

The alarm generation unit 21 is provided in the vehicle 1 to detect a steering angle of the vehicle 1 and send out a detection output SS representing the detected steering angle of the vehicle 1 from the steering angle detection unit 23. Is also supplied. The alarm generation unit 21 is supplied with the alarm signal SAM transmitted from the alarm signal transmission unit 20 and generates an alarm when the steering angle represented by the detection output SS from the steering angle detection unit 23 is smaller than a predetermined value. When the warning signal SAM is not supplied from the warning signal transmitting unit 20 and when the warning signal SAM is supplied from the warning signal transmitting unit 20, but the detection output SS from the steering angle detecting unit 23 indicates the steering. When the angle is equal to or larger than a predetermined value, no alarm is issued.

When the alarm generator 21 operates in this manner, when the vehicle 1 is likely to deviate from the lane 3, an alarm is issued from the alarm generator 21. If the driver of the vehicle 1 is in the traveling lane 3
When the steering is performed to avoid a situation where the vehicle deviates from the predetermined value, and the steering angle of the vehicle 1 is equal to or larger than a predetermined value, the alarm from the alarm generation unit 21 is stopped accordingly. Therefore, after an alarm is issued from the alarm generation unit 21,
The driver of the vehicle 1 steers to avoid a situation in which the vehicle 1 deviates from the driving lane 3, so that the vehicle 1 does not deviate from the driving lane 3. Until the lateral displacement becomes less than the alarm reference, the alarm from the alarm generation unit 21 is continued, and as a result, a situation in which the driver of the vehicle 1 feels troublesome with the alarm is avoided.

Under these circumstances, the lateral displacement of the vehicle 1 changes as shown by the broken line in FIG. 8 according to the deviated yaw angle and the traveling speed of the vehicle 1, and the time in FIG. At t1, when the lateral displacement of the vehicle 1 changes from the state where the lateral displacement is less than the alarm standard to the state where the alarm standard is reached, the alarm generation unit 21 immediately issues an alarm. Thereafter, the driver of the vehicle 1 performs steering to avoid a situation in which the vehicle 1 deviates from the traveling lane 3, and at a time t2, when the steering angle of the vehicle 1 reaches a predetermined value, the vehicle 1 Even if the displacement is equal to or greater than the alarm reference, the alarm from the alarm generator 21 is stopped. Thereafter, the lateral displacement of the vehicle 1 is reduced by the steering of the driver of the vehicle 1, and at a time point t3, the lateral displacement of the vehicle 1 is returned to a state less than the alarm reference.
At this time, the warning period during which a warning is issued from the warning generation unit 21 is a period from time t1 to time t2.

It is to be noted that the alarm generation section 21 includes a steering angle detection section 23.
Is not supplied and the control based on the detection output SS from the steering angle detection unit 23 in the alarm generation unit 21 is not performed, at the time t1 in FIG.
An alarm generation unit 2 started when the lateral displacement of the vehicle 1 changes from a state where the lateral displacement is less than the alarm standard to a state where the alarm standard is reached.
After that, the warning from 1 is continued until the lateral displacement of the vehicle 1 is reduced by steering by the driver of the vehicle 1 and the lateral displacement of the vehicle 1 is returned to a state below the warning reference at time t3. And the alarm generation unit 2 at that time
The alarm period during which an alarm is issued from 1 is a period from time t1 to time t3.

FIG. 10 shows another example of the vehicle position and direction angle detecting device according to the present invention. This example can also be applied to the vehicle 1 shown in FIG. 2 instead of the example shown in FIG.

The example shown in FIG. 10 includes many parts configured similarly to the example shown in FIG. therefore,
In FIG. 10, each part shown in FIG. 1 and further a part corresponding to each signal and data, and further a signal and data,
1 are denoted by the same reference numerals as in FIG. 1, and redundant description thereof will be omitted.

In the example shown in FIG. 10, a yaw rate sensor 30 is provided in addition to the road marker sensor 6. The yaw rate sensor 30 is, for example, a vibration gyroscope that can be obtained relatively inexpensively, detects a yaw rate that is a change in the yaw angle of the vehicle 1, and sends out a detection output SYR that indicates the detected yaw rate. Therefore, the yaw rate sensor 30 detects a change in the yaw angle of the vehicle 1,
That is, a direction angle change detecting means for detecting a change in a direction angle formed by the front-rear direction of the vehicle 1 with respect to the arrangement direction 5A of the road surface marker 5 is formed.

The detection output SYR sent from the yaw rate sensor 30 is supplied to a yaw angle estimator 31. The yaw angle estimator 31 detects the detection output S from the yaw rate sensor 30.
The yaw angle of the vehicle 1 is estimated and detected based on the yaw rate represented by the YR, vehicle direction angle data DYW 'representing the estimated and detected yaw angle of the vehicle 1 is formed, and the vehicle direction angle data DYW' is output to an output terminal. 32. Such a yaw angle estimating unit 31 estimates and detects the yaw angle of the vehicle 1 based on the detection output SYR obtained from the yaw rate sensor 30 forming the direction angle change detecting means, and detects the estimated yaw angle of the vehicle. An auxiliary vehicle direction angle estimating means for obtaining the data DYW 'is formed.

The vehicle direction angle data DYW ′ obtained from the yaw angle estimating unit 31 is supplied to the vehicle position estimating unit 33. The vehicle position estimating unit 33 is also supplied with a detection output SV, which is a voltage signal corresponding to the traveling speed of the vehicle 1 and is sent from the vehicle state detecting unit 7. The vehicle position estimating unit 33 calculates the yaw angle of the vehicle 1 represented by the vehicle direction angle data DYW ′ obtained from the yaw angle estimating unit 31 and the traveling speed of the vehicle 1 represented by the detection output SV transmitted from the vehicle state detecting unit 7. Based on the above, the position of the vehicle 1 with respect to the array 5A of the road surface markers 5 is estimated and detected, and the vehicle position data DPV ′ representing the estimated position of the vehicle 1 with respect to the array 5A of the road surface markers 5 is obtained. Position data D
PV ′ is output to the output terminal 34. Such a vehicle position estimating unit 33 is based on the vehicle direction angle data DYW ′ obtained from the yaw angle estimating unit 31 forming the auxiliary vehicle direction angle estimating unit and the detection output SV obtained from the vehicle state detecting unit 7.
An auxiliary vehicle position estimating means for estimating and detecting the position of the vehicle 1 with respect to the array 5A of the markers 5 and obtaining vehicle position data DPV 'representing the estimated and detected position of the vehicle 1 is formed.

Then, in the example shown in FIG.
A switch 35 that selectively supplies the vehicle direction angle data DYW derived to the output terminal 14 and the vehicle direction angle data DYW ′ derived to the output terminal 32 to the warning unit 16, and a vehicle derived to the output terminal 15 A switch 36 is provided for selectively supplying the position data DPV and the vehicle position data DPV ′ derived to the output terminal 34 to the warning unit 16. These switches 35 and 36 are interlocked with each other. Note that the vehicle direction angle data DYW is used without using the switches 35 and 36.
And vehicle direction angle data DYW 'and vehicle position data DPV and vehicle position data DPV' can be selected by data processing.

Further, in the example shown in FIG.
The vehicle direction angle data DYW derived to the output terminal 14 is
The data is supplied to the reliability determination unit 37. In the reliability determination unit 37, the reliability of the vehicle direction angle data DYW is determined, and a determination output SLN and a determination output SLG are formed according to the reliability. The judgment output SLN is the switch 3
5 and 36, and the judgment output SLG is supplied to the correction signal forming unit 38.

The switches 35 and 3 from the reliability judgment section 37
6 is output from the vehicle direction angle data D
If YW has high reliability and is suitable for practical use, it takes a high level, and the vehicle direction angle data DYW
However, if its reliability is low and it is not suitable for practical use, it takes a low level. When the determination output SLN is at a high level, the switch 35 is in a state of supplying the vehicle direction angle data DYW derived to the output terminal 14 to the warning unit 16, and the switch 36 is in a state where the vehicle is derived to the output terminal 15. The position data DPV is supplied to the warning unit 16. On the other hand, when the determination output SLN is at a low level, the switch 35 is in a state of supplying the vehicle direction angle data DYW ′ derived to the output terminal 32 to the warning unit 16, and the switch 36 is derived to the output terminal 34. The vehicle position data DPV ′ is supplied to the warning unit 16.

From the reliability judging section 37 to the correction signal forming section 38
Is supplied to the vehicle direction angle data DY
When W has high reliability and is suitable for practical use, it is assumed that it changes according to the reliability of the vehicle direction angle data DYW, and the vehicle direction angle data DYW has low reliability, When it is not suitable for practical use,
Not formed.

The correction signal forming section 38 includes a reliability determining section 37
When the vehicle directional angle data DYW supplied to the controller has high reliability and is suitable for practical use, the reliability determination unit 37
Signal SIM corresponding to the judgment output SLG supplied from the
And supplies it to the yaw angle estimation unit 31. In the yaw angle estimating unit 31, when the correction signal SIM is supplied from the correction signal forming unit 38, the correction control based on the correction signal SIM is performed, and the yaw angle estimation unit 31 estimates and detects the correction based on the correction according to the correction signal SIM. When the vehicle direction angle data DYW ′ indicating the yaw angle is obtained, and when the correction signal SIM is not supplied from the correction signal forming unit 38, the correction signal SIM is supplied from the correction signal forming unit 38. The vehicle direction angle data DYW 'representing the yaw angle estimated and detected is obtained using the last yaw angle estimated and detected under the correction in accordance with the correction signal SIM as an initial value. .

Such a correction control by the correction signal SIM in the yaw angle estimating unit 31 is performed, for example, by detecting the detection output SY from the yaw rate sensor 30 in the yaw angle estimating unit 31.
When the yaw angle of the vehicle 1 is estimated and detected based on R, errors are prevented from being accumulated. Under such correction control, when the correction signal SIM is not supplied from the correction signal forming unit 38, the yaw angle of the vehicle 1 based on the detection output SYR from the yaw rate sensor 30 in the yaw angle estimating unit 31 is calculated. The estimation detection is started in a state where there is no accumulated error. As a result, the correction signal SIM from the correction signal forming unit 38 is supplied to the yaw angle estimation unit 31.
Is not supplied, the yaw angle estimating unit 31 obtains the vehicle direction angle data DYW ′ representing the yaw angle of the vehicle 1 estimated and detected with significantly improved accuracy.

Other than the correction control based on the correction signal SIM in the yaw angle estimating section 31, the yaw angle estimating section 31
In the above, when the yaw angle of the vehicle 1 is estimated and detected based on the detection output SYR from the yaw rate sensor 30, an offset correction value that eliminates an offset error in the detection output SYR from the yaw rate sensor 30 is set. It is assumed to be. Under such correction control, even when the correction signal SIM is not supplied from the correction signal forming unit 38, the vehicle based on the detection output SYR from the yaw rate sensor 30 in the yaw angle estimating unit 31 The yaw angle estimation detection of 1 is performed under the condition that the offset error in the detection output SYR from the yaw rate sensor 30 is eliminated by the offset correction value set in the yaw angle estimation unit 31.

The detection output SY from the yaw rate sensor 30
The offset in R is an output of the yaw rate sensor 30 obtained when the yaw rate of the vehicle 1 detected by the yaw rate sensor 30 is “0”. The yaw rate of the vehicle 1 detected by the yaw rate sensor 30 is Ω,
Assuming that the output of the yaw rate sensor 30 is V _in , the sensitivity coefficient of the yaw rate sensor 30 is K, and the offset in the detection output SYR from the yaw rate sensor 30 is V _O , the following relationship holds: Ω = (V _in −V _O ) / K. .

[0058] When the yaw angle of the vehicle 1 and .theta.a, yaw angle .theta.a of the vehicle 1, since it is determined by integrating the yaw rate Ω of the vehicle 1, the theta ₀ as the initial value of the yaw angle, Delta] t
Is the sampling frequency, θa = θ ₀ + ∫ΩdtΣθ ₀ + ΣΩΔt = θ ₀ + ΔtΣ
(V _in -V _O ) / K.

Therefore, when the yaw rate of the vehicle 1 is Ω ′ and the yaw angle of the vehicle 1 is θa ′ when the offset error ΔV _O is added to the offset V _O , Ω ′ = [V _in − (V _O + ΔV _O) )] / K θa ′ ≒ θ ₀ + ΔtΣ (V _in −V _O ) / K−ΔtΣΔV
It was reveal the _O / K, therefore, the error Derutashitaei for yaw angle .theta.a of the vehicle 1 caused by the offset error [Delta] V _O is expressed as Δθa = θa'-θa ≒ -Δt ΣΔV O / K.

From the relationship of the last equation, the offset error V _O in the detection output SYR from the yaw rate sensor 30 is accumulated with the passage of time, and the yaw angle θa of the vehicle 1 is obtained.
It can be seen that the error Δθa for

Accordingly, as described above, the correction signal forming unit 3
8, when the correction signal SIM is not supplied, the detection output S from the yaw rate sensor 30 in the yaw angle estimation unit 31
If the yaw angle estimation and detection of the vehicle 1 based on the YR are to be started without any accumulated error, the yaw angle estimation unit 31 sends the correction signal SI from the correction signal forming unit 38 to the yaw angle estimation unit 31.
When M is not supplied, the vehicle direction angle data DYW 'representing the yaw angle of the vehicle 1 estimated and detected with significantly improved accuracy is obtained from the yaw angle estimation unit 31.

The reliability of the vehicle direction angle data DYW supplied from the yaw angle estimating unit 13 to the reliability determining unit 37 depends on the detection status of the road marker 5 by the road marker sensor 6, This depends on the state of the detection output SM. That is, under the condition that the detection output SM from the road surface marker sensor 6 is properly obtained, the vehicle direction angle data DYW from the yaw angle estimation unit 13 supplied to the reliability determination unit 37 has high reliability. If the road marker sensor 6 is significantly separated from the array 5A of the road markers 5 and the detection output SM from the road marker sensor 6 is not properly obtained, the reliability determination is performed. The vehicle direction angle data DYW supplied from the yaw angle estimation unit 13 to the unit 37 has low reliability and is not suitable for practical use.

Therefore, in the example shown in FIG.
Under the condition that the detection output SM from the road marker sensor 6 is properly obtained, the vehicle direction angle data DYW from the yaw angle estimation unit 13 derived from the output terminal 14 and the vehicle position derived from the output terminal 15 The vehicle position data DPV from the estimating unit 10 is supplied to the switch 35 and the switch 36, respectively.
The warning signal is supplied to the warning unit 16 through the control unit, and the yaw angle estimation unit 31 forms a correction signal based on the reliability of the vehicle direction angle data DYW from the yaw angle estimation unit 13 determined by the reliability determination unit 37. The correction control based on the correction signal SIM obtained from the unit 38 is performed. Also,
Under the condition that the detection output SM from the road marker sensor 6 is not properly obtained, the vehicle direction angle data DYW from the yaw angle estimating unit 13 derived from the output terminal 14 and the vehicle derived from the output terminal 15 Instead of the vehicle position data DPV from the position estimating unit 10, the vehicle direction angle data DYW 'from the yaw angle estimating unit 31 derived to the output terminal 32, and the vehicle position estimating unit 33 derived from the output terminal 34 Is supplied to the warning unit 16 through the switch 35 and the switch 36, respectively.

As a result, the vehicle can be obtained with high accuracy both when the detection output SM from the road marker sensor 6 is obtained properly and when the detection output SM from the road marker sensor 6 is not obtained properly. 1 road surface marker 5
Representing the position (vehicle position data DPV or vehicle position data DPV ') of the array 5A and data representing the yaw angle of the vehicle 1 (vehicle direction angle data DYW).
Alternatively, the vehicle direction angle data DYW ′) is supplied to the warning unit 16.

The warning unit 16 includes the warning unit 16 shown in FIG.
Similarly to the above, for example, it has a specific configuration as shown in FIG.

In the above example, the road surface marker 5
Takes a positive voltage value when it is shifted to the right with respect to the road surface marker, takes a reference level "0" when it is located right above the road marker 5, and is at a position shifted to the left with respect to the road marker 5. When one road marker sensor 6 that generates a detection output that takes a negative voltage value is provided, instead of such a road marker sensor 6, for example, a positive detection output corresponding to the road marker 5 is provided. It is also possible to use two road surface marker sensors that cause the above, and to provide them on the left and right sides of the vehicle.

[0067]

As is apparent from the above description, in the vehicle position and direction angle detecting apparatus according to the present invention, the marker position is determined based on the detection output of the markers arranged on the road on which the vehicle travels. The position of the vehicle is estimated and detected. Along with that, vehicle position data representing the position of the vehicle estimated and detected is formed, and the position history data formed based on the vehicle position data is used to estimate the movement locus of the vehicle on the road, Vehicle trajectory data representing the estimated vehicle trajectory is formed. Then, the yaw angle of the vehicle is estimated and detected based on the vehicle locus data.

Therefore, according to the vehicle position and direction angle detecting device of the present invention, the position of the vehicle with respect to the marker array is estimated based on the detection output of the markers arranged on the road on which the vehicle travels. The detection and the estimation based on the estimation of the yaw angle of the vehicle do not depend on the imaging means and the image processing means or the yaw rate sensor and the yaw rate processing means. Without inviting
In addition, even when the vehicle travels for a relatively long time, it can be performed with high accuracy.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an example of a vehicle position and direction angle detection device according to the present invention.

FIG. 2 is a perspective view showing a vehicle to which an example of the vehicle position and direction angle detection device according to the present invention is applied, and a road on which the vehicle travels.

FIG. 3 is a time chart for explaining the operation of the road marker sensor in the example shown in FIG. 1;

FIG. 4 is a conceptual diagram serving to explain the operation of a vehicle position estimating unit in the example shown in FIG. 1;

FIG. 5 is a conceptual diagram serving to explain operations of a vehicle trajectory estimating unit and a yaw angle estimating unit in the example shown in FIG. 1;

FIG. 6 is a conceptual diagram serving to explain the operation of a vehicle trajectory estimating unit in the example shown in FIG. 1;

FIG. 7 is a block diagram showing a specific configuration example of a warning unit in the example shown in FIG. 1;

8 is a time chart for explaining the operation of a specific configuration example of the alarm signal transmitting unit shown in FIG. 7;

FIG. 9 is a characteristic diagram used for describing the operation of a specific configuration example of the warning signal transmission unit shown in FIG. 7;

FIG. 10 is a block diagram showing another example of the vehicle position and direction angle detection device according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vehicle 3 Traveling lane 5 Road marker 5A Road marker array 6 Road marker sensor 7 Vehicle state detector 8 Road structure data transmitter 9 Marker arrangement data transmitter 10, 33 Vehicle position estimator 11 Vehicle position data memory 12 Vehicle trajectory estimation Unit 13, 31 yaw angle estimating unit 14, 15, 32, 34 output terminal 16 warning unit 20 warning signal sending unit 21 warning generating unit 22 vehicle speed detecting unit 23 steering angle detecting unit 30 yaw rate sensor 37 reliability determining unit 38 correction signal formation Department

Claims (12)

[Claims] 1. A marker detecting means provided in a vehicle for detecting markers arranged on a road on which the vehicle travels as the vehicle travels, based on a detection output obtained from the marker detecting means. Vehicle position estimating means for estimating and detecting the position of the vehicle with respect to the marker array and obtaining vehicle position data representing the position of the estimated and detected vehicle; obtaining the position history data for the vehicle by storing the vehicle position data Vehicle position history data forming means; vehicle locus estimating means for estimating a moving locus of the vehicle on the road using the position history data, and obtaining vehicle locus data representing the estimated moving locus of the vehicle; Based on the vehicle trajectory data, a direction angle formed by the front-rear direction of the vehicle with respect to the arrangement direction of the markers is estimated and detected, and the estimated direction angle is calculated. And a vehicle direction angle estimating means for obtaining vehicle direction angle data. 2. The apparatus according to claim 1, wherein each of the markers arranged on the road is a magnetic marker, and the marker detecting means obtains a detection output in response to a magnetic field formed by the magnetic marker. Vehicle position and direction angle detection device. 3. A road structure data transmitting means for transmitting road curvature data indicating a curvature of a road on which a vehicle travels, and a marker arrangement data transmitting means for transmitting marker interval data indicating a mutual interval between markers arranged and arranged on the road. The vehicle position and direction angle detection device according to claim 1, wherein the road curvature data and the marker interval data are used for estimating the position of the vehicle with respect to the marker by the vehicle position estimating means. 4. A vehicle state detecting means for detecting a running speed of a vehicle and obtaining vehicle speed data representing the detected running speed, wherein the vehicle speed data is used for estimating a moving locus of the vehicle by a vehicle locus estimating means. The vehicle position and direction angle detecting device according to claim 1, wherein: 5. A vehicle trajectory estimating means for setting a complementary curve relating to a vehicle trajectory, and matching the complementary curve with position history data obtained from a vehicle position history data forming means to determine parameters of the complementary curve. 2. The vehicle position and direction angle detecting device according to claim 1, wherein the trajectory of the vehicle is estimated using a complementary curve obtained by determining the parameters. 6. A vehicle trajectory estimating means for calculating a vehicle trajectory curve from a vehicle motion model, and matching the vehicle trajectory curve with position history data obtained from a vehicle position history data forming means. 2. The vehicle position and direction angle detecting device according to claim 1, wherein parameters of the curve are determined, and the vehicle trajectory is estimated using a vehicle trajectory curve obtained by determining the parameters. 7. An apparatus according to claim 1, further comprising a warning unit for issuing a warning in accordance with the vehicle position data obtained from the vehicle position estimation unit and the vehicle direction angle data obtained from the vehicle direction angle estimation unit. A vehicle position and direction angle detection device according to any one of claims 1 to 3. 8. The vehicle position and direction angle detecting device according to claim 7, wherein the warning means issues a warning when the marker detection by the marker detection means is not performed for a predetermined period. 9. A direction angle change detecting means for detecting a change in a direction angle formed by the front-rear direction of the vehicle with respect to the arrangement direction of the markers,
Auxiliary vehicle direction angle estimating means for estimating and detecting the direction angle of the vehicle based on the detection output obtained from the direction angle change detecting means and obtaining vehicle direction angle data representing the estimated detected direction angle; Estimating the position of the vehicle with respect to the marker array based on vehicle state detecting means for detecting speed, vehicle direction angle data obtained from the auxiliary vehicle direction angle estimating means, and detection output obtained from the vehicle state detecting means. An auxiliary vehicle position estimating means for obtaining vehicle position data representing the position of the detected and estimated vehicle.
In a situation where the detection output from the marker detecting means is not properly obtained, the vehicle position data obtained from the auxiliary vehicle position estimating means and the vehicle direction angle data obtained from the auxiliary vehicle direction angle estimating means are used. The vehicle position and direction angle detecting device according to claim 1, wherein: 10. Under the condition that the detection output from the marker detecting means is properly obtained, the auxiliary vehicle directional angle estimating means performs a correction control in accordance with the vehicle direction angle data obtained from the vehicle direction angle estimating means. The vehicle position and direction angle detecting device according to claim 9, wherein the vehicle direction angle data corrected from the vehicle direction angle estimating means is obtained. 11. A reliability judging means for judging the reliability of the vehicle direction angle data obtained from the vehicle direction angle estimating means, and a correction signal forming section for obtaining a correction signal corresponding to the judgment output obtained from the reliability judging means. 11. The vehicle position and direction angle detection device according to claim 10, wherein correction control for auxiliary vehicle direction angle estimation means is performed by a correction signal obtained from the correction signal forming unit. 12. The vehicle position data obtained from the vehicle position estimating means and the vehicle direction angle data obtained from the vehicle direction angle estimating means, or the vehicle position data obtained from the auxiliary vehicle position estimating means and the auxiliary vehicle direction angle estimating means. The vehicle position and direction angle detection device according to claim 9, further comprising a warning unit that issues a warning according to the obtained vehicle direction angle data.