JPH1021500A - Vehicle speed controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively prevent the occurrence of an unforeseen situation at the time of sudden acceleration or deceleration by obtaining position information on a road and gradually correcting the detection position of a vehicle when the vehicle passes through a place where a position information providing means is locally installed on the road. SOLUTION: The reader 4 is locally installed on the road and the reader 4 reads a marker M giving position information. The distance between the vehicles is obtained based on the position of the front vehicle, which is received by a communication part 3, while the detection position of the vehicle is successively corrected based on position information which is read. The control target quantity of speed at which the vehicle travels while following the front vehicle, is calculated so that the obtained distance between the vehicles becomes the distance with the vehicles, which is previously set, and a driving command is suitably given to the accelerator driving part 6 of the vehicle and a brake driving part 7. The travel speed of the vehicle is controlled by an operation control part 5. Thus the occurrence of the unforeseen situation can be prevented at the time of temporary sudden acceleration or deceleration.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle speed control device for automatically controlling the running speed of a vehicle so as to follow a preceding vehicle while maintaining a constant inter-vehicle distance.

[0002]

2. Description of the Related Art Recently, when a vehicle is automatically driven at a predetermined speed on a dedicated road on which facilities for automatic driving are installed,
The position on the road on which the vehicle is traveling is independently detected, the position of the preceding vehicle is known by inter-vehicle communication, and the inter-vehicle distance to the preceding vehicle is obtained from the position of the own vehicle at that time, and the obtained inter-vehicle distance is obtained. Has been developed in which the traveling speed of the own vehicle is controlled so that the vehicle speed becomes a preset inter-vehicle distance.

[0003]

The problem to be solved is to transmit and receive the position of the vehicle autonomously detected by the inter-vehicle communication so as to follow the preceding vehicle while keeping the inter-vehicle distance constant. When the vehicle speed control is performed, the position error on the road on which the vehicle is traveling is inevitably detected, and the position error directly decreases the followability of the vehicle ahead. It is becoming.

In order to improve the following ability, it is necessary to correct the position of the vehicle detected on the road on the road, but if the amount of correction of the position is large, the vehicle is corrected based on the corrected position. When speed control is performed so that the corrected inter-vehicle distance becomes appropriate, sudden acceleration or deceleration is temporarily performed, and a sudden approach to the preceding or following vehicle may occur. Will happen.

[0005]

SUMMARY OF THE INVENTION The present invention detects a position on a road on which a vehicle is traveling, receives data of the position of a preceding vehicle by inter-vehicle communication, and forwards data from the position of the own vehicle at that time. A vehicle speed control device that determines the inter-vehicle distance to a vehicle and controls the traveling speed of the own vehicle so that the obtained inter-vehicle distance becomes a predetermined inter-vehicle distance, corrects a detection position of the vehicle on a road. In order to improve controllability and to prevent sudden acceleration or deceleration from being performed temporarily when correcting the position, local information providing means is provided locally on the road so that the vehicle can adjust its position. When passing through the place where the information adding means is installed,
Means for obtaining the position information on the road and correcting the detected position of the vehicle is adopted, and then the position is corrected gradually.

Further, the present invention detects the position and running speed of a vehicle on a road, receives data of the position and running speed of a preceding vehicle by inter-vehicle communication, and detects the position of the own vehicle at that time. A vehicle speed control device which calculates an inter-vehicle distance and a relative speed with respect to a preceding vehicle from the traveling speed and calculates an appropriate inter-vehicle distance, and controls a traveling speed of the own vehicle so as to maintain the appropriate inter-vehicle distance. In order to improve the controllability by correcting the detected position on the road and improve the controllability, local position information is added locally on the road so that sudden acceleration or deceleration is not temporarily performed when the position is corrected. Means is provided so that when a vehicle passes through a location where the position information providing means is installed, means for obtaining position information on the road and correcting the detected position of the vehicle is adopted. In Ue, so that causes gradual correction of its position.

[0007]

Now, a case in which a vehicle is automatically driven at a predetermined speed on a dedicated road on which equipment for automatic driving is installed will be described.
This will be described below.

In that case, the vehicle speed control device according to the present invention
As shown in FIG. 1, a position detection unit 1 for detecting a position on a road on which the own vehicle is traveling, and transmission and reception of position data between vehicles.
A communication unit 3 for performing reception, a reader 4 for reading a marker M provided with position information locally provided on a road, and, while sequentially correcting the detection position of the own vehicle based on the read position information, An inter-vehicle distance from the own vehicle is calculated based on the position of the preceding vehicle received by the communication unit 3, and the vehicle follows the preceding vehicle so that the calculated inter-vehicle distance becomes a predetermined inter-vehicle distance. An arithmetic control unit 5 which calculates a control target amount at such a speed and gives an appropriate drive command to an accelerator driving unit 6 and a brake driving unit 7 of the own vehicle to control the running speed of the own vehicle. .

If the running speed of the vehicle is not set to a predetermined value, a speed detecting unit 2 for detecting the running speed of the own vehicle is provided. After the transmission and reception of the speed data are performed, the inter-vehicle distance and the relative speed with respect to the own vehicle are obtained based on the position and the traveling speed of the preceding vehicle received by the communication unit 3, and the appropriate inter-vehicle at that time is obtained. The distance is calculated by a predetermined calculation process, and a control target amount of a speed at which the vehicle follows the preceding vehicle while traveling while maintaining the proper inter-vehicle distance is calculated, and the accelerator driving unit 6 and the brake driving unit 7 of the own vehicle are obtained. , A driving command is given as appropriate to control the traveling speed of the own vehicle.

As the position detecting unit 1, for example, a unit based on self-contained navigation in which a position on a road is cumulatively determined by a predetermined arithmetic processing while detecting a traveling distance and a traveling direction from a starting point is used. In this case, it goes without saying that the position information of the own vehicle in the on-vehicle navigation device can be used. When the road on which the vehicle travels is specified, the position on the road can be obtained by measuring the traveling distance from the starting point. Furthermore, in the case of automatically traveling while detecting magnetic nails driven at a constant interval (1 m interval) by a magnetic sensor provided on the vehicle side to guide the traveling of the vehicle on a road surface dedicated to automatic traveling, By counting the number of magnetic nails from the starting point, the position on the road can be obtained.

As the marker M for adding position information and the reader 4 for reading the marker, for example, a marker M in which position information is coded is provided on a road surface in advance at each location that divides a road into sections. When the vehicle passes over the marker M, the reader 4 can read the position information of the marker M.

Specifically, for example, it is conceivable to provide a marker by a bar code and read the position information by a bar code reader.

Further, when the vehicle travels on a dedicated road automatically while detecting a magnetic nail driven into a road surface by a magnetic sensor, a predetermined portion of the magnetic nail array is used as a marker, and the magnetic sensor is used as a reader. It becomes possible to read the position information coded as.

In this case, as shown in FIG. 2, a row of magnetic nails X are driven on the road surface of the automatic driving road ADR at regular intervals so that the N poles thereof are directed upward so as to guide the traveling of the vehicle. Of these, a predetermined number of magnetic nails X1, X2, X3,... At each location that divides the dedicated road ADR are coded by appropriately changing the polarities, and that portion is used as a marker M for providing position information.

Here, for example, a special road ADR of 10
Using the five magnetic nails X1 to X5 at the beginning of each section, the first magnetic nail X1 is used as a position information flag so that the upper part becomes an S pole, By changing the respective polarities of the four magnetic nails X2 to X5 that follow, the binary coded position (section) information is represented. That is, X2 is the south pole “1”, and X3 to X5 are all the north pole “0”.
To represent the section B1. Also, X
2 to the north pole “0”, X3 to the south pole “1”, X4 and X
5 is set to N pole "0" to indicate section B2, X2 and X3 are both set to S pole "1", and X4 and X5 are set to N pole "0" to indicate section B3. Hereinafter, the same applies.

When the amount of information is relatively small as described above, the position on the dedicated road ADR is not directly assigned, but the relation between each section number and the position of the dedicated road ADR is previously set in the arithmetic control unit 5 in a table. The position on the corresponding dedicated road ADR may be obtained from the read section number.

An appropriate inter-vehicle distance is obtained from the inter-vehicle distance and the relative speed between the host vehicle and the preceding vehicle, and a control target amount for the speed at which the vehicle follows the preceding vehicle while traveling while maintaining the appropriate inter-vehicle distance is determined. Conventional methods are widely applied as a method for outputting the same.

Further, when the vehicle automatically travels on a dedicated road provided with facilities for automatic traveling, if data on the inter-vehicle distance in accordance with the traveling speed instruction is transmitted from the roadside transmitter, the data is not transmitted. The control target amount of the speed that maintains the inter-vehicle distance according to the running speed is calculated.

With the above-described structure, when a position on the road is determined based on the traveling distance of the vehicle, the occurrence of a position error due to a change in tire diameter or meandering due to air pressure cannot be denied. Further, the occurrence of a position error due to a missing count of the number of magnetic nails cannot be denied. Therefore, the position error causes a decrease in accuracy of vehicle speed control for following the preceding vehicle while maintaining an appropriate inter-vehicle distance.

Therefore, according to the present invention, the actual position on the road is determined from the position information read by the reader 4 every time the vehicle passes a marker M provided with position information locally provided on the road. Knowing that, the position of the vehicle that has been detected independently is corrected.

However, at this time, if the amount of correction of the position is large, when the speed control is performed such that the inter-vehicle distance corrected based on the corrected position becomes appropriate, temporary control is performed. Sudden acceleration or deceleration occurs,
A situation in which the vehicle immediately approaches the preceding vehicle or the following vehicle may occur.

For this reason, in the present invention, in particular, in order to prevent such an unexpected situation from occurring, the arithmetic and control unit 5 employs means for gradually correcting the position of the vehicle. I have.

More specifically, a low-pass filter process is performed to gradually change the data at the position detected independently by the reader 4 so that the data at the position detected by the reader 4 can be gradually changed over time without sudden change. I do.

FIG. 3 shows a state of a change in the amount of positioning by itself when no filter processing is performed. In this case, at the time point P when the marker M provided on the road is read by the reader 4, the error [epsilon] of the self-contained positioning amount rapidly changes.

FIG. 4 shows a state of a change in the amount of positioning by itself when the filter processing is performed. In this case,
At the time point P when the marker M provided on the road is read by the reader 4, the error ε of the self-sustained positioning amount gradually changes over time.

Further, the vehicle position may be gradually corrected irrespective of the correction amount.
If the correction amount of the position is small and the adjustment of the inter-vehicle distance accompanying the correction does not cause much problem even if it is performed sharply, a normal position correction without low-pass filter processing may be performed.

In this case, for example, the threshold value of the correction amount of the position is set to about 3 m, and the error between the position detected independently and the actual position on the road obtained from the position information is 3 m or less. In some cases, normal position correction is performed, and when the distance exceeds 3 m, the position is corrected by low-pass filter processing.

FIG. 5 shows a processing flow at that time.

If the error between the position detected independently and the actual position on the road obtained from the position information is extremely large, for example, exceeding 8 m, correction of the position is stopped. Thus, it is also possible to easily give the driver a warning to that effect to grasp the current situation of the own vehicle.

When setting a threshold value for the amount of position correction,
When the inter-vehicle distance is a function of speed, the appropriate inter-vehicle distance for the preceding vehicle changes depending on the traveling speed of the vehicle at that time, and when the traveling speed is relatively low and the appropriate inter-vehicle distance is set to be short. Since the correction of the position of the vehicle has a large effect, if the threshold value is variably set so as to be a function of the traveling speed of the vehicle, the position can be corrected more appropriately. become.

The means for adding position information and reading the position information is not limited to the marker M and the reader 4, and as another means, a transmission facility for adding position information by means of a beacon or a sign post is provided at an appropriate place on the road. When passing through the transmission facility, the position information transmitted from the transmission facility may be received by a receiver provided in the vehicle.

Further, instead of gradually correcting the position of the vehicle by low-pass filtering, the deviation between the position detected independently and the actual position obtained by reading the given position information is proportionally calculated. It goes without saying that other means such as gradually changing the operation step by step can be used.

[0033]

As described above, according to the vehicle speed control device of the present invention, the position on the road on which the vehicle is traveling is detected, the data of the position of the preceding vehicle is received by inter-vehicle communication, and the position of the own vehicle at that time is received. When the distance between the vehicle and the preceding vehicle is obtained from the vehicle, and the traveling speed of the own vehicle is controlled so that the obtained distance between the vehicles becomes a predetermined distance between the vehicles, the position information provided by the vehicle locally on the road By obtaining position information on the road when passing through the providing means and gradually correcting the position of the own vehicle, sudden acceleration or deceleration is temporarily performed and unexpected situations may occur. This has the advantage that the occurrence can be effectively prevented and accurate vehicle speed control can be performed.

According to the present invention, the position and the traveling speed of the vehicle on the road are detected, and the data of the position and the traveling speed of the preceding vehicle are received by inter-vehicle communication. From the position and traveling speed of the vehicle, the appropriate inter-vehicle distance is calculated by calculating the inter-vehicle distance and the relative speed with respect to the preceding vehicle, and when controlling the traveling speed of the own vehicle so as to maintain the appropriate inter-vehicle distance, when the vehicle By obtaining position information on the road when passing through the position information providing means provided in the vehicle, and gradually correcting the position of the own vehicle, rapid acceleration or deceleration is temporarily performed. This has the advantage that an unexpected situation can be effectively prevented and accurate vehicle speed control can be performed.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of a vehicle speed control device according to the present invention.

FIG. 2 is a diagram illustrating an example of a state in which a part of a row of magnetic nails for driving guidance driven into a road dedicated to automatic driving is used as a marker for adding position information.

FIG. 3 is a characteristic diagram illustrating an example of a state of a change in a positioning amount in an autonomous state when filter processing is not performed.

FIG. 4 is a characteristic diagram illustrating an example of a state of a change in a positioning amount in a self-supporting state when a filtering process is performed.

FIG. 5 is a diagram illustrating an example of a flow of a process for correcting a position of a vehicle detected independently.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Position detection part 2 Speed detection part 3 Communication part 4 Reader 5 Operation control part 6 Accelerator drive part 7 Brake drive part

Claims (7)

[Claims] 1. A position on a road on which a vehicle is traveling is detected, data of a position of a preceding vehicle is received by inter-vehicle communication, and an inter-vehicle distance to the preceding vehicle is obtained from the position of the own vehicle at that time. In a vehicle speed control device that controls the traveling speed of the own vehicle so that the obtained inter-vehicle distance becomes a preset inter-vehicle distance, a position information providing means locally installed on a road; Means for obtaining position information on the road when passing the place where the providing means is installed, and correcting the detected position of the vehicle, and gradually correcting the position of the own vehicle. A vehicle speed control device characterized by the above-mentioned. 2. A position and a traveling speed on a road on which the vehicle is traveling are detected, data of a position and a traveling speed of a preceding vehicle are received by inter-vehicle communication, and the data of the own vehicle and the traveling speed at that time are received. In a vehicle speed control device that calculates the appropriate inter-vehicle distance by obtaining the inter-vehicle distance and relative speed with respect to the preceding vehicle and controls the traveling speed of the own vehicle so as to maintain the appropriate inter-vehicle distance, a position locally installed on the road Information providing means, and means for obtaining position information on the road when the vehicle passes through the location where the position information providing means is installed, and correcting the detected position of the vehicle, and providing the position of the own vehicle. A vehicle speed control device characterized in that the vehicle speed is gradually corrected. 3. The method according to claim 1, wherein when the amount of correction of the detected position of the vehicle is equal to or larger than a predetermined threshold value, the position of the vehicle is corrected gradually.
The vehicle speed control device according to the description of the section. 4. The vehicle speed control device according to claim 3, wherein the threshold value is variably set according to the running speed of the vehicle. 5. The apparatus according to claim 1, wherein the position information providing means is a marker provided on a road, and a reader provided on the vehicle reads the coded position information of the marker. Alternatively, the vehicle speed control device according to the second aspect. 6. The method according to claim 1, wherein the position information providing means is a magnetic nail embedded on a road, and a magnetic sensor provided in the vehicle reads the coded position information of the magnetic nail. A vehicle speed control device according to claim 1 or 2. 7. The apparatus according to claim 1, wherein the position information providing means is a transmission facility installed on the road, and receives the position information transmitted from the transmission facility by a receiver provided in the vehicle. A vehicle speed control device according to claim 1 or 2.