JPH10253370A - Absolute position computing method for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable highly accurate specified followup control of vehicles even when a fine difference is noted in the direction among the vehicles during the alignment of vehicles and even when specified followup errors are generated according the accuracy of arithmetic processing and control concerning an absolute position computing method of vehicles. SOLUTION: There are arranged the first step (step S30) in which the ongoing directions of vehicles before and after the starting thereof are calculated from the absolute position information of the vehicles measured before the starting thereof utilizing a satellite navigation system and the absolute position information of the vehicles measured immediately after the starting of the vehicles utilizing the satellite navigation system, the second step (step S40) in which angles of yawing generated in the vehicles are measured before and after the starting thereof, the third step (step S50) in which the directions of vehicles are calculated before the starting thereof from the ongoing directions of the vehicles and the angles of yawing and the fourth step (steps S100 and S110) in which the absolute positions of the vehicles are computed from a vehicle speed and the angles of yawing using the absolute position before the starting of the vehicles and the directions of the vehicles before the starting thereof as initial values.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for calculating the absolute position of a vehicle, which calculates the absolute position of the vehicle, and more particularly to a method for calculating the absolute position of the vehicle, which is suitable for automatic follow-up control of the vehicle.

[0002]

2. Description of the Related Art In recent years, in order to streamline transportation by lorries and reduce traffic accidents, development of an automatic following system using an expressway or the like has been promoted. The auto-following traveling system automatically drives an unmanned (or manned) following vehicle on a leading vehicle driven by the driver, thereby reducing the number of drivers and causing a collision caused by a drowsy driving or the like. Accidents and the like can be prevented beforehand.

As such an automatic following system, various systems such as a vehicle following system, a trajectory following system, and a driving information communication system have been proposed. Of these, in the trajectory-following automatic following travel system, the following vehicle measures the position of the leading vehicle using a relative position sensor or the like, and further translates and rotates this position with the movement of the own vehicle. The traveling locus of the leading vehicle in the coordinate system is obtained, and the steering amount is controlled so that the deviation angle becomes zero.

For example, in such an automatic following system, a leading vehicle 100 includes a controller (ECU) 102, a yaw rate sensor 103, a vehicle speed sensor 104, a communication device 105, and a communication antenna 106, as shown in FIG. It is composed. The leading vehicle 100 is controlled by a controller 102 by a yaw rate sensor 103 and a vehicle speed sensor 1.
The travel trajectory of the host vehicle is calculated based on the detection information from 04.

The travel locus information calculated by the controller 102 is transmitted to the communication device 105 and the communication antenna 1.
06 to the following vehicle 101. On the other hand, the following vehicle 101 also has a controller (ECU) 1
07, a yaw rate sensor 108, a vehicle speed sensor 109, a communicator 111, and a communication antenna 110. The controller 107 determines the traveling locus of the own vehicle (following vehicle) based on detection information from the yaw rate sensor 108 and the vehicle speed sensor 109. It is designed to calculate.

[0006] The controller 107 compares the traveling locus information of the own vehicle (following vehicle) with the traveling locus information of the leading vehicle received via the communication antenna 110 and the communication device 111 so that they match. In this manner, the steering control and the vehicle speed control are performed, and the following vehicle 101 is made to follow the leading vehicle 100 in this manner.

[0007]

However, in such a conventional automatic following system, the following vehicle 101 is guided based on a traveling locus calculated based on detection information from the yaw rate sensor 103 and the vehicle speed sensor 104. Since the vehicle 100 is caused to follow the vehicle 100, a predetermined following error occurs depending on the accuracy of the arithmetic processing and the accuracy of the control.

For this reason, the following accuracy of the following vehicle is improved,
Japanese Patent Application Laid-Open No. 8-282326 discloses a technique for eliminating the accumulation of errors in the lateral direction when a number of following vehicles are automatically followed.
In this technique, while the leading vehicle transmits at least the traveling trajectory information including the lateral position of the own vehicle by the transmission unit,
The following vehicle receives the traveling locus information transmitted from the leading vehicle by the receiving means, and determines the driving control amount including the steering amount of the own vehicle by the driving control amount determining means based on the received traveling locus information. I have.

However, in this technique, first, the leading vehicle and the following vehicle are vertically aligned in a flat and straight place, and the vehicle distances are matched by making the lateral distance to a reference line such as a center line the same. However, in this case, it is difficult to accurately align them, and it is inevitable that some errors occur. In addition, since the coordinates for calculating the trajectory of the vehicle are set for each vehicle, if there is a misalignment between the leading vehicle and the following vehicle when starting, the coordinates of the coordinates between the leading vehicle and the following vehicle are changed. Absolute direction will be different.

In this case, even if the steering amount of the following vehicle is controlled based on the traveling locus information of the leading vehicle so that the traveling locus of the following vehicle is the same as the traveling locus of the leading vehicle,
The actual trajectory of the following vehicle does not coincide with the trajectory of the leading vehicle, and the error between the trajectory of the leading vehicle and the trajectory of the following vehicle gradually increases. The present invention has been made in view of such a problem, and when performing vehicle following control, even if there is a small difference in the direction of the vehicle at the time of vehicle alignment, it also depends on arithmetic processing accuracy and control accuracy. It is an object of the present invention to provide a method for calculating the absolute position of a vehicle, which can perform high-precision vehicle following control even if a predetermined following error occurs.

[0011]

According to a first aspect of the present invention, there is provided a method for calculating an absolute position of a vehicle according to the present invention, wherein the absolute position information of the vehicle measured before the vehicle starts using a satellite navigation system and the satellite. A first step of calculating a traveling direction of the vehicle before and after the vehicle starts from the absolute position information of the vehicle measured immediately after the vehicle starts using a navigation system; and calculating a yaw angle generated in the vehicle before and after the vehicle starts. A second step of measuring; a third step of calculating a direction of the vehicle before the start from the vehicle traveling direction and the yaw angle; an absolute position before the start and a direction of the vehicle before the start A fourth step of calculating the absolute position of the vehicle from the vehicle speed and the yaw angle with the initial value as the initial value.

According to a second aspect of the present invention, there is provided a method for calculating an absolute position of a vehicle according to the first aspect, based on the absolute position information of the vehicle measured using the satellite navigation system. A fifth step of correcting the absolute position of the vehicle calculated in step 4 is performed. After the correction, the absolute position of the vehicle is calculated from the corrected absolute position of the vehicle, and the subsequent vehicle speed and yaw angle. It is characterized by.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIGS. 1 to 4 are diagrams for explaining an absolute position calculating method of a vehicle according to an embodiment of the present invention. Since the vehicle absolute position calculation method according to the present embodiment is used in a vehicle follow-up control system,
First, a vehicle tracking control system will be described.

This vehicle follow-up control system controls a plurality of follow-up vehicles 31 to follow one lead vehicle 11 on a traveling road 10 such as an expressway.
As shown in FIG. 1, a driver 12 is mounted on the leading vehicle 11, and the steering wheel 13 and the engine 1 are driven in accordance with the external environment such as the bending of the traveling path 10 and the speed limit.
4, transmission (T / M) 15, brake 16
Are performed. Then, control information of the steering 13, the engine 14, the transmission 15, the brake 16, and the like is transmitted to a communication ECU 20, which will be described later.

Further, the leading vehicle 11 is provided with an ECU 19, which runs the vehicle based on detection information from a vehicle speed sensor 17 for detecting a running speed and a yaw rate sensor 18 for detecting a yaw angular speed. The trajectory is calculated. The traveling locus of the host vehicle (leading vehicle 11) is also transmitted to the communication ECU 20.

The leading vehicle 11 has a satellite navigation system antenna (hereinafter referred to as GPS antenna) 24 and a satellite navigation system receiver (hereinafter referred to as GPS receiver).
The GPS antenna 24 and the GPS receiver 25 can receive absolute position information (absolute coordinate data, GPS data) from the artificial satellite 50. The absolute position information detected by the GPS receiver 25 is also transmitted to the communication ECU 20.

The satellite navigation system uses an artificial satellite 50 in order to obtain more accurate absolute position information.
A high-accuracy satellite navigation system (high-accuracy GPS) that receives not only absolute position information from the satellite but also information from the base station 51 whose latitude and longitude are clear. The communication ECU 20 manages information related to reception or transmission. The communication ECU 20 receives travel locus information of the own vehicle from the ECU 19, absolute position information from the GPS receiver 25, and control information of the steering 13, the engine 14, the transmission 15, the brake 16, and the like. The data is transmitted to the immediately following vehicle 31 via the inter-communication device 21. The communication ECU 20 also receives control information of the immediately following vehicle 31 via the front-to-back communication device 21.

A display panel 22 is provided near the driver's seat of the leading vehicle 11 so that information transmitted from the communication ECU 20 to the immediately following vehicle 31 via the front-to-back communication device 21 is displayed. Thus, the driver 12 can know the information transmitted from the communication ECU 20 to the immediately following vehicle 31 via the front-to-back communication device 21. In FIG. 1, reference numeral 23 denotes a reflector that reflects a light beam from the following distance sensor 39 provided on the following vehicle 31.

On the other hand, the following vehicle 31 is provided with an operation mode changeover switch 42 for switching between an automatic mode and a manual mode. When the operation mode is the auto mode, the steering ECU 3 is controlled by the control ECU 32 instead of the driver.
3, the operation of the engine 34, the transmission 35, the brake 36, and the like is performed. When the operation mode switch 42 is switched to the manual mode, the driver can drive the vehicle, similarly to the leading vehicle 11.

For this reason, the control ECU 32
The control ECU 32 has detection information from a vehicle speed sensor 37 for detecting the traveling speed of the own vehicle, a yaw rate sensor 38 for detecting the yaw angular velocity, and an inter-vehicle distance sensor 39 for measuring the inter-vehicle distance with the leading vehicle 11. Is sent. Further, the following vehicle 31 is provided with a communication ECU 40 that manages information related to reception or transmission.
And receives the traveling locus information and the absolute position information of the leading vehicle 11 transmitted from the control ECU 32 and transmits the information to the control ECU 32. Further, the communication ECU 40 includes the control ECU 3
2 is transmitted to the front-to-back communication device 21 of the preceding vehicle 11 via the front-to-back communication device 41a.

The communication ECU 40 is also connected to a front-to-back communicator 41b for communicating with the immediately following vehicle, and transmits various kinds of information to the immediately following vehicle via the front-to-back communicator 41b. To be sent to the car. Also,
The following vehicle 31 is provided with a GPS antenna 44 and a GPS receiver 45. The GPS antenna 44 and the GPS receiver 45 use the base station 51 in addition to the absolute position information (absolute coordinate data) from the artificial satellite 50. Information from the Internet. Then, the absolute position information received by the GPS receiver 45 is stored in the control ECU 32.
Is sent to

When the absolute position information from the artificial satellite 50 cannot be received in a tunnel or the like, the absolute position information received by the control ECU 32 is not changed. Then, it is determined whether or not the location is such as in a tunnel where the absolute position information cannot be received, based on whether or not the absolute position information has changed. Then, based on the detection information from the inter-vehicle distance sensor 39, the control ECU 32 sets the actual inter-vehicle distance between the leading vehicle 11 and the following vehicle 31 to a safe inter-vehicle distance according to the vehicle speed or the like in advance.
The output control of the engine 34 and the operation control of the brake 36 are performed, and the movement of the following vehicle 31 in the front-rear direction (vertical direction) is controlled.

On the other hand, the movement of the following vehicle 31 in the left-right direction (lateral direction) is based on the detection information from the vehicle speed sensor 37 and the yaw rate sensor 38, and the movement of the leading vehicle 11 and the moving position of the following vehicle 31 is determined. The deviation is obtained and controlled by operating and controlling the steering 33 so as to reduce the deviation. When such a following vehicle 31 is controlled, the correction means 32A provided in the control ECU 32
Thereby, the position of the following vehicle 31 is periodically corrected.

Next, the following control of the vehicle using the method for calculating the absolute position of the vehicle according to the present embodiment will be described with reference to the flowchart shown in FIG. As shown in FIG. 2, in step S10, the control ECU 3 of the following vehicle 31
2 determines whether or not the following vehicle 31 has started (started), that is, whether or not the following vehicle 31 has traveled a predetermined distance, in order to determine the traveling direction before and after the following vehicle 31 starts.

If it is determined that the following vehicle 31 has not started, the process proceeds to step S20, in which the output control of the engine 34 and the operation of the brake 36 of the following vehicle 31 are performed to control the front and rear of the vehicle. The control in the direction is performed, and this control is repeated until it is determined that the following vehicle 31 has started. When it is determined that the following vehicle 31 has started in this way, the following vehicle 31 is controlled in the front-rear direction and the left-right direction to follow the leading vehicle 11.

Then, the process proceeds to a step S30, wherein the following vehicle 3
The first control ECU 32 uses the GPS data (absolute position coordinates of the following vehicle) before and after the starting of the following vehicle 31 received by the GPS receiver 45 to execute the vehicle traveling directions before and after the following vehicle 31 starts, that is, the absolute coordinates. Of the traveling direction θ _gps1 (see FIG. 3) of the following vehicle 31 with respect to the X axis is calculated (first step).

That is, the control ECU 32 of the following vehicle 31
The traveling direction angle θ of the following vehicle 31 with respect to the absolute coordinate X axis
_As shown in FIG. 3, _gps1 is _defined as an absolute position (X ₀ , Y ₀ ) of the following vehicle 31 based on the GPS data and an absolute position (X ₁ , X ₁ ) of the following vehicle 31 based on the GPS data.
Y ₁ ) and the following equation. θ _gps1 = tan ⁻¹ [(Y ₁ −Y ₀ ) / (X ₁ −X ₀ )] (1) In FIG. 3, the vertical axis is the X axis and the horizontal axis is the Y axis. In addition, the following vehicle 31 can receive GPS data by the GPS receiver 45 at regular intervals from the state before the vehicle starts.

Next, in step S40, the control ECU32 followers wheel 31, the output of the yaw rate sensor 38 by double integration, calculates the yaw angle theta ₁ which occurs in the following vehicle 31 around the start of the tracking wheel 31 (Second step), step S5
Go to 0. In step S50, the traveling direction angle θ _gps1 of the following vehicle 31 obtained in step S30 and step S4
From the yaw angle Θ ₁ of the following vehicle 31 calculated with 0, the following vehicle 3
The first control ECU 32 calculates the direction of the following vehicle 31 before starting, that is, the angle θ ₀ of the following vehicle 31 with respect to the X axis of the absolute coordinates before starting (third step).

[0029] That is, as shown in FIG. 3, the absolute of the follow-up wheel 31 of the forward shifting obtained by subtracting from the traveling direction angle theta _GPS1 yaw angle theta ₁ which occurred before and after the start of the follow-up wheel 31 of the follow-up wheel 31 The angle (θ _gps1 −Θ ₁ ) of the coordinates with respect to the X axis is set as the initial angle θ ₀ , and at the same time, the initial yaw angle Θ ₀ is set to ₀ as the initial setting. Thus, the angle (θ _gps1 −
Θ ₁ ) is obtained, and the direction of the following vehicle 31 before starting is known. If this is taken into account and the following vehicle 31 is followed, the traveling caused by a small difference in the direction of the vehicle when the vehicle is set is set. The deviation of the trajectory can be prevented, and a high-precision following can be performed.

After the following vehicle 31 starts following the vehicle, the control ECU of the following vehicle 31 proceeds to step S60.
32 determines whether or not the following vehicle 31 is in a location where GPS data cannot be received, such as in a tunnel, based on whether or not the GPS data from the GPS receiver 45 has changed. If the result of this determination is that the GPS data has changed, step S
The process proceeds to step 70, where it is determined whether or not the current position is the position correction cycle for correcting the position of the following vehicle 31 based on the GPS data.
Proceed to step S100.

The position correction cycle is a predetermined period for correcting a tracking error generated in accordance with the accuracy of the arithmetic processing and the control, and the first position after a lapse of a predetermined time from the start of the tracking. A correction cycle is coming. In step S100, the control ECU 32 of the following vehicle 31 outputs the yaw rate sensor 38 and the vehicle speed sensor 3
7, the yaw angle Θ _n and the vehicle speed V _n detected based on the detected output are read, and then, step S110 is performed.
In, as shown in FIG. 3, the predicted position in the absolute coordinate of the follow-up wheel 31 and a yaw angle theta _n and the vehicle speed V _n of the follow-up wheel 31 (X
_N ', Y _N' calculates a) (fourth step). In addition,
The expected position (X _N ′, Y _N ′) refers to the position of the following vehicle 31 obtained by calculation.

That is, in this case, the GPS data changes.
The direction of the following vehicle 31 according to the above equation (1).
In other words, the angle θ of the absolute coordinates of the following vehicle 31 with respect to the X axis
_gpsNCan not be asked. Therefore, the following vehicle 31
Initial angle θ₀And initial yaw angle Θ ₀And the current yaw angle Θ_nWhen
Based on the predicted position (X
_N', Y_N') Is calculated as shown below.

First, an expected yaw angle θ _N ′ in absolute coordinates of the following vehicle 31 is obtained by the following equation. Note that the expected yaw angle θ _N ′ refers to the yaw angle of the following vehicle 31 obtained by calculation. θ _N '← θ ₀ + Θ _n −Θ _{0 In} this case, the initial angle θ ₀ and the initial yaw angle Θ ₀ immediately after starting.
Until is updated, it can be expressed by the following equation.

Θ_N′ ← θ_gps1−Θ₁+ Θ_nAbsolute coordinates of this following vehicle 31
Expected yaw angle θ at_N', The absolute seat of the following vehicle 31
Expected position (X_N', Y_N′) And
It is determined by equations (2) and (3). X_N'← ∫V_n・ Cos θ_N'... (2) Y_N'← ∫V_n・ Sin θ_N′ (3) In this manner, the X-axis of the absolute coordinates of the following vehicle 31 before starting
Angle θ_gps0Is calculated, the yaw rate sensor 38
And yaw angle Θ detected by vehicle speed sensor 37, respectively.
_n, Vehicle speed V_nBased on the absolute coordinates of the following vehicle 31
Expected position (X _N', Y_N′)
Therefore, the following vehicle 31 receives GPS data from inside the tunnel
Even if you enter a place where you cannot
The vehicle can follow the guide vehicle 11.

After the expected position (X _N ′, Y _N ′) of the following vehicle 31 in the absolute coordinates is obtained in this way, in step S 90, the expected position (X _N ′) of the following vehicle 31 in the absolute coordinates is obtained.
_N ′, Y _N ′) and the expected yaw angle θ _N ′ in absolute coordinates
, The steering 33 is operated and controlled to reduce the deviation from the traveling locus of the leading vehicle 11, and the following vehicle 31 is controlled.
Of the following vehicle 31 in the front-rear direction by controlling the output of the engine 34 and the operation of the brake 36 to control the movement of the following vehicle 31 in the front-rear direction. And the process returns to step S60.

Steps S60, S70, and S10 are performed until the next position correction cycle.
0, steps S110 and S90 are repeated. Thereafter, when the position correction cycle starts, step S7 is performed.
From 0, the process proceeds to step S80, and the direction θ _gpsN of the following vehicle 31 is calculated from the GPS data before and after the change. That is, since the absolute position of the previous track wheel 31 and _{(X N-1, Y N} -1) absolute position of the current follow-up wheel 31 (X _N, Y _N) and by the above equation (1), follow-up wheel 31, that is, the angle θ _gpsN of the absolute coordinates of the following vehicle 31 with respect to the X axis is determined, and
Proceed to 85.

In step S85, control E of the following vehicle 31 is performed.
The correction means 32A of the CU 32 determines in step S110
Expected position of the following vehicle 31 in absolute coordinates
(X_N', Y _N') Is received by the GPS receiver 45.
Absolute position (X_N, Y _N)
With the following vehicle 31 determined in step S110.
Expected yaw angle θ in absolute coordinates_N'In step S80
Of the following vehicle 31 determined by_gpsNReplace with
And the absolute position of the following vehicle 31 (X_N, Y_N)
And the absolute yaw angle θ of the following vehicle 31_N(Fifth unit
Tep). At the same time, in step S85, θ₀←
θ_gpsN, Θ₀← Θ_nAs the initial angle θ₀And initial yaw angle
Θ₀To update.

The processes in steps S80 and S85 are performed only when it is determined in step S70 that the cycle is a position correction cycle determined as a fixed cycle.
The correction based on the GPS data is performed periodically. In this way, the expected position (X _N ′, Y _N ′) of the following vehicle 31 in absolute coordinates and the expected yaw angle θ _N ′ in the absolute coordinates are calculated by the absolute position (X _N , Y _N ) of the following vehicle 31.
_Also , by performing the correction periodically with the direction θ _gpsN of the following vehicle 31, even if a predetermined following error occurs according to the arithmetic processing accuracy or the control accuracy, it becomes possible to perform high-precision vehicle following control. In addition, since the initial angle θ ₀ and the initial yaw angle Θ ₀ are also updated, the correction result is determined in the subsequent step S10.
0, S110, and the accuracy of the predicted yaw angle θ _N ′ can be kept high.

Next, the process proceeds to step S90, where
85, the absolute position of the following vehicle 31 (X _N , Y
_N ) and the absolute yaw angle θ _N , the steering 33 is operated and controlled so that the deviation from the running locus of the leading vehicle 11 is reduced, and the following vehicle 31 is controlled in the left-right direction. By performing the output control and the operation control of the brake 36, the movement of the following vehicle 31 in the front-back direction is controlled, and the following vehicle 31 follows the leading vehicle 11,
It returns to step S60.

And until the next position correction cycle.
Are steps S60, S70, S10
0, repeat the processing of step S110 and step S90
You. In this case, the correction means 32A of the control ECU 32
The corrected absolute position of the following vehicle 31 (X_N, Y_N) And additional
Absolute yaw angle θ of slave vehicle 31_NVehicle speed of the following vehicle 31 based on
V and yaw angle_nAnd the absolute coordinates of the following vehicle 31
Expected position (X _N', Y_N′) And expected yaw angle
θ_N'Is required.

If the following vehicle 31 enters a location where GPS data cannot be received, such as in a tunnel, it is determined in step S60 that the GPS data has not changed, and the process proceeds to step S100. S10
0, the processing of steps S110 and S90 is repeated. As a result, the following vehicle 31 is positioned in the GPS
Even if the vehicle enters a place where data cannot be received, the following vehicle 31 can be made to accurately follow the leading vehicle 11.

In the following control operation of the following vehicle 31, the operation of the control based on the absolute position of the vehicle will be described. As shown by the broken line in FIG. 4, when the following vehicle 31 is not controlled based on the absolute position of the vehicle (that is, when the following vehicle is not controlled based on GPS data), the traveling locus of the following vehicle 31 is the traveling locus of the leading vehicle 11. Even if it is controlled to be the same as that of the leading vehicle 11, if there is a deviation in the direction of the vehicle before the start,
Gradually deviates from the traveling locus of the vehicle, and a large error occurs.

On the other hand, as shown by the solid line in FIG.
When controlling the following vehicle 31 based on the absolute position of the vehicle (that is, not controlling based on the GPS data),
The traveling locus of the leading vehicle 11 and the actual traveling locus of the following vehicle 31 can be made to substantially match. As a result, there is an advantage that the following performance in the following control of the vehicle can be improved.

That is, when the following control of the vehicle is performed, the vehicle
Even if there is a slight difference in the direction of the vehicle during both sets,
Following vehicle 31 before departure from absolute position of following vehicle 31 before and after advance
Direction θ_gps0And the direction θ of the following vehicle 31 before the start
_gps0And the absolute position (X₀, Y ₀) Is the initial value
The expected position (X_N', Y_N′)
, The following vehicle 31 is controlled,
There is an advantage that accurate vehicle following control can be performed.

After _obtaining the direction θ _gps0 of the following vehicle 31 before starting, the yaw rate sensor 38 and the vehicle speed sensor 37
The expected position (X _N ′, Y _N ′) in the absolute coordinates of the following vehicle 31 is determined based on the detection output of the following vehicle, so that the following vehicle 31 enters a place where GPS data cannot be received, such as in a tunnel. Even in this case, there is an advantage that the following vehicle 31 can accurately follow the leading vehicle 11.

Further, when the following vehicle 31 is controlled so as to follow the leading vehicle 11, even if a predetermined following error occurs according to the accuracy of the arithmetic processing and the control accuracy, G is periodically determined.
Since the position of the following vehicle 31 is corrected based on the PS data, the vehicle following control can be performed with high accuracy. Although the method for calculating the absolute position of the vehicle according to the present embodiment has been described as being used for follow-up control of the vehicle, the application of the method for calculating the absolute position of the vehicle is not limited to this. It can be used as a method to know the position.

In the method for calculating the absolute position of a vehicle according to the present embodiment, the calculation is performed based on the absolute position information of a high-precision GPS.
May be used to calculate the absolute position of the vehicle.

[0048]

As described above in detail, according to the method for calculating the absolute position of a vehicle according to the first aspect of the present invention, the satellite navigation system cannot be used while the vehicle is running in a tunnel or the like. Even in such a case, there is an advantage that the absolute position of the vehicle can be accurately calculated.

According to the method for calculating the absolute position of a vehicle according to the second aspect of the present invention, the absolute position calculated based on the vehicle speed and the yaw angle is periodically corrected based on information from the satellite navigation system. There is an advantage that the calculation accuracy of the absolute position based on the vehicle speed and the yaw angle can be increased. Another advantage is that even when the satellite navigation system cannot be used, the calculation accuracy of the absolute position of the vehicle can be improved.

[Brief description of the drawings]

FIG. 1 is a configuration diagram schematically showing a vehicle follow-up control system according to an embodiment of the present invention.

FIG. 2 is a flowchart for explaining an absolute position calculation method of the vehicle follow-up control system according to one embodiment of the present invention.

FIG. 3 is a schematic diagram for explaining an absolute position calculation method of the tracking control system according to one embodiment of the present invention.

FIG. 4 is a schematic diagram for explaining the operation and effect of the vehicle follow-up control system according to one embodiment of the present invention.

FIG. 5 is a configuration diagram schematically showing a conventional vehicle follow-up control system.

[Explanation of symbols]

11 Leading Car 12 Driver 13, 33 Steering 14, 34 Engine 15, 35 Transmission 16, 36 Brake 17, 37 Vehicle Speed Sensor 18, 38 Yaw Rate Sensor 19 ECU 20, 40 Communication ECU 21, 41a, 41b Front and Rear Communication Device 22 Display Panel 23 , 43 reflector 24, 44 satellite navigation system antenna (GPS antenna) 25, 45 satellite navigation system receiver (GPS receiver) 31, 51 follower vehicle 32 control ECU 32A correction means 39 inter-vehicle distance sensor 42 mode changeover switch 50 artificial Satellite (high-accuracy satellite navigation system) 51 Base station of high-accuracy satellite navigation system 100 Lead vehicle 101 Follower vehicle 102, 107 Controller (ECU) 103, 108 Yaw rate sensor 104, 109 Vehicle speed sensor 105, 11 communication device 106, 110 communication antenna

Claims (2)

[Claims] 1. A vehicle is started from absolute position information of a vehicle measured before the vehicle starts using a satellite navigation system and absolute position information of the vehicle measured immediately after the vehicle starts using the satellite navigation system. A first step of calculating a vehicle traveling direction before and after, a second step of measuring a yaw angle generated in the vehicle before and after the vehicle starts, and the vehicle before starting from the vehicle traveling direction and the yaw angle A fourth step of calculating the absolute position of the vehicle from the vehicle speed and the yaw angle using the absolute position before the start and the direction of the vehicle before the start as initial values. And a step of calculating the absolute position of the vehicle. 2. The method according to claim 1, further comprising: a fifth step of correcting the absolute position of the vehicle calculated in the fourth step based on the absolute position information of the vehicle measured using the satellite navigation system. 2. The absolute position calculating method according to claim 1, further comprising: calculating the absolute position of the vehicle from the corrected absolute position of the vehicle and the subsequent vehicle speed and yaw angle.