JPH10100738A - Automatic follow-up car and automatic follow-up system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow a following car to run in pursuit of a foregoing car using a simple configuration. SOLUTION: A foregoing car 11 calculates the position using a GPS module 112 and transmits an appropriate signal to a following car 130 through a transmitter 118 and an antenna 119. The following car 130 draws the running locus of the foregoing car 110 using the time as address, and the speed and steering angle of itself 130 are determined on the basis of the obtained running locus, and the running control is made in such a way as tracing the running locus while the target inter-car distance is kept properly.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to, for example, an automatic following vehicle and an automatic following system that follow a preceding vehicle driven by a passenger while maintaining a constant inter-vehicle distance.

[0002]

2. Description of the Related Art Conventionally, in an autonomous vehicle (an autonomous vehicle driven by an autopilot, also referred to as an autopilot vehicle or a self-propelled vehicle), a lane marking of a road is recognized by a video camera or embedded in the road. Sensing the magnetic marker
It has been considered that the vehicle is driven along a road by performing steering control of the own vehicle.

In this case, when a preceding vehicle is present, the following vehicle (the following vehicle) measures the inter-vehicle distance (also referred to as inter-vehicle distance) from the preceding vehicle using a radar or the like, and performs the steering control. Independent inter-vehicle distance control is performed.

[0004]

However, in an autonomous vehicle that uses a video camera to recognize the travel path and perform steering control, the configuration of processing the output signal of the video camera becomes complicated, and this is performed at high speed. At the moment, there is a problem that the cost is high.

[0005] In the automatic driving in which the steering is controlled by sensing the magnetic marker, it is essential that a so-called infrastructure such as a road on which the magnetic marker is laid is provided. There is a problem that it takes time and cost to maintain the structure.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has an automatic following vehicle and an automatic following system which can follow a preceding vehicle with a simple configuration and at low cost. The purpose is to provide.

[0007]

SUMMARY OF THE INVENTION An automatic following vehicle according to the present invention includes a receiver for receiving travel trajectory data of a preceding vehicle from the preceding vehicle, and a vehicle speed of the own vehicle based on the received travel trajectory data. And a control plan creating means for creating a plan for the steering angle and an actuator for controlling the vehicle speed and the steering angle of the own vehicle based on the created plan.

According to the present invention, it is possible to follow the preceding vehicle and travel with a simple configuration having the receiver, the control plan creating means, and the actuator.

Further, the automatic following system according to the present invention calculates the two-dimensional position data of the own vehicle by the two-dimensional position calculating means, and transmits the calculated two-dimensional position data to the rear following vehicle by the transmitter. The received two-dimensional position data is received by the receiver, and based on the received two-dimensional position data, the two-dimensional position indicated by the two-dimensional position data is
And a following vehicle that performs automatic driving control so as to advance the position of the own vehicle.

According to the present invention, as a result, the following vehicle performs the automatic driving control so as to follow the trajectory of the two-dimensional position received from the preceding vehicle, so that the following vehicle can be controlled.

As the two-dimensional position calculating means, a GPS receiver can be used. In addition, the following vehicle is also equipped with a GPS receiver, and by controlling the speed of the following vehicle so that both positions at the same time are at a constant distance, the inter-vehicle distance between the preceding vehicle and the following vehicle is kept constant. Follow-up operation can be performed. In addition, the inter-vehicle distance is, for example,
It can be determined by mounting a laser radar.

[0012]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a schematic configuration of an automatic tracking system 100 to which an embodiment of the present invention is applied. The automatic following system 100 is arranged on a traveling road such as a highway (not shown) in the direction of arrow A (also referred to as traveling direction A).
And a follower vehicle (follower vehicle) 130 that travels following the vehicle (leading vehicle).

The leading vehicle 110 basically has a GPS receiving antenna 111, a GPS module 112 connected thereto, a wheel pulse sensor 114, and output signals from the GPS module 112 and the wheel pulse sensor 114. The supplied control module 116, a transmitter 118 connected to the output side of the control module 116, and a transmitting antenna 11 for inter-vehicle transmission connected to the transmitter 118
9 is provided.

In practice, the leading vehicle 110 has a configuration in which these components are mounted on a general ordinary vehicle, for example, a passenger vehicle, that is, a vehicle on which a passenger operates by operating the steering, accelerator and brake. Is done.

In this embodiment, a module is a standardized unit or component, and generally refers to a component having various defined functions therein. Includes a CPU functioning as control / judgment means and the like, and a ROM and a RAM serving as storage means. "Module"
Is a thing and is also called a device.

On the other hand, the following vehicle 130 basically has a communication module 1, a control planning module 2, a lateral control module 3, and a vehicle speed control module 4. Module 1,
It is configured to transmit and receive data to and from 3 and 4. In this case, the control planning module 2 and the vehicle speed control module 4
Constitutes the preceding vehicle following control means.

The output of the receiving antenna 140 for inter-vehicle reception is supplied to the communication module 1.

The output of the yaw rate sensor 5 and the output of the GPS antenna 141 are
An output via the PS module 6, an output from the wheel pulse sensor 8, and an output from a start switch 12 for automatic operation (automatic traveling) are supplied. Control planning module 2
Supplies an output to the audio output device 17 and the display device 18.

The output of the yaw rate sensor 5 is supplied to the lateral control module 3. Lateral control module 3
Corresponds to the EPS (El) provided in the steering operation transmission system.
Actuator (EP), which is an electric power steering (electronic power steering) device
Also called S. ) 14 to provide the output.

The output of the wheel pulse sensor 8, the longitudinal acceleration sensor 9, the laser radar 10, and the brake pedal switch 13 are supplied to the vehicle speed control module 4. The vehicle speed control module 4 includes an actuator (also referred to as a throttle CBW) 1 that is a throttle CBW (Controlled By Wire) provided in a throttle system.
5 and an actuator (also referred to as a brake pressure control brake) 16 which is a boost pressure control brake provided in the brake system. Note that the throttle CBW
15 and the brake pressure control brake 16
It is an electronic control in the same manner as described above.

The automatic tracking system 100 according to this embodiment
Is basically configured as described above. Next, the automatic following operation of the preceding vehicle 110 by the following vehicle 130 will be described.

The automatic following operation mainly includes two operations of the following vehicle, that is, a vehicle speed control operation and a steering (steering) control operation for the preceding vehicle. Therefore, the automatic following operation will be described below. Do it in order. A. Vehicle speed control processing of the following vehicle 130 B. First, a steering (steering) control process of the following vehicle 130 will be described. The vehicle speed control process of the following vehicle 130 will be described with reference to a flowchart shown in FIG. The subject of the control is any of the modules 1 to 4. The vehicle speed control process is a process equivalent to the technology described in Japanese Patent Application No. 7-283973.

The control planning module 2 confirms that the start switch 12 for automatic traveling is in an on state, and starts creating information for automatic following travel (step S1).

Next, it is determined whether or not the brake pedal switch 13 is off (step S2).
When the vehicle is in the ON state, that is, when the brake is artificially applied, the vehicle speed control process from the next step S3 is not performed.

More specifically, when the conditions of step S1 and step S2 are satisfied, the start switch 12 is turned on and the brake pedal switch 1 is turned on.
When the switch 3 is in the off state, the process of step S3 is performed. The processing in step S3 is performed according to the current vehicle 1
The position of the vehicle 30 (in this case, the following vehicle 130) (also referred to as the current position coordinates) Xa, the speed (vehicle speed) Va of the own vehicle,
And the calculation processing of the acceleration Aa of the own vehicle.

The vehicle position Xa is obtained by using the GPS module 6 which also functions as a two-dimensional position (two-dimensional coordinate position) calculating means. As is well known, the GPS module 6 has a function of receiving radio waves transmitted from a plurality of GPS satellites by the reception antenna 141 and calculating three-dimensional position data (latitude data, longitude data, and altitude data) of the vehicle. Of which, two of the latitude and longitude excluding the altitude data
The three-dimensional position data (two-dimensional position coordinate data) is supplied from the GPS module 6 to the control planning module 2.

The two-dimensional position data is the vehicle position Xa itself. Since the own vehicle speed Va is the amount of change in the own vehicle position Xa per unit time, the position difference between the previously obtained two-dimensional position data and the currently obtained two-dimensional position data is the time difference when the data was obtained. The divided value, that is, the vehicle position X
a is obtained by time-differentiating a, and the acceleration Aa of the own vehicle is obtained by time-differentiating the own vehicle speed Va. Note that the own vehicle speed Va is also obtained from the output of the wheel pulse sensor 8 that outputs one pulse per one rotation of the wheel.

Next, the vehicle position Xat and the vehicle speed Vat after a lapse of a predetermined time (T seconds) are predicted (step S4). It has been confirmed by experiments that the following vehicle 130 can smoothly follow the preceding vehicle 110 by selecting this constant time T to about 1 to 2 seconds.
= 1.5 seconds.

Vehicle position Xat and vehicle speed V after T seconds
It is easily understood that at can be calculated from the current vehicle position Xa, the vehicle speed Va, and the acceleration Aa of the vehicle by the following equations (1) and (2).

Xat = Xa + Va · T + (１ ／) Aa · T ² (1) Vat = Va + Aa · T (2) Note that the own vehicle position Xa, Xat, own vehicle speed V
a, Vat and the host vehicle acceleration Aa are stored in the control plan module 2
It is stored as a set in the RAM inside.

Next, position information of the preceding vehicle 110 is received from the preceding vehicle 110 (step S5). The leading vehicle 110
Since the GPS module 112 is provided similarly to the following vehicle 130, the current position of the preceding vehicle 110 is known, and the current position information of the preceding vehicle 110 (two-dimensional position data,
(Dimensional position coordinates) together with the reception time of the current position are transmitted via the control module 116 and the transmitter 118 to the transmission antenna 119
Is transmitted as radio waves through the following vehicle 130.
Of the preceding vehicle 110 (the preceding vehicle position) Xb can be known by the communication module 1 having the receiver. In this embodiment, the output signal of the wheel pulse sensor 114 is also transmitted from the leading vehicle 110 and received.

The control planning module 2 obtains the preceding vehicle speed Vb by differentiating the received preceding vehicle position Xb, and obtains the preceding vehicle acceleration Ab by further differentiating (step S6).

Next, the leading vehicle position Xbt and the leading vehicle speed Vbt of the leading vehicle 110 after T seconds are calculated by the following equations (3) and (4) corresponding to the above equations (1) and (2). ) Determined by the formula.

Xbt = Xb + Vb · T + (１ ／) Ab · T ² (3) Vbt = Vb + Ab · T (4) Also in this case, the preceding reception is performed using the reception time of the position by the GPS module 112 as an address. Car position X
b, Xbt, preceding vehicle speed Vb, Vbt, preceding vehicle acceleration A
b is stored in the RAM in the control planning module 2 as a set. The data string of the preceding vehicle position Xb stored in the RAM means traveling trajectory data Xc of the preceding vehicle 110 (illustrated and described later).

The vehicle speed control module 4 has the following formula (1)
The throttle based on the own vehicle position Xat after T seconds, the own vehicle speed Vat after T seconds, the preceding vehicle position Xb after T seconds, and the preceding vehicle speed Vbt after T seconds calculated by the equation (4). CBW1
5 to calculate the commanded acceleration Ap for determining whether to increase the speed of the own vehicle (following vehicle) 130 or to control the boost pressure control brake 16 to reduce the speed of the own vehicle 130. (Step S8).

FIG. 3 shows a detailed flowchart of a subroutine for calculating the designated acceleration Ap. Therefore, first, a predicted position difference Dp (Dp = Xbt−Xat) between the preceding vehicle 110 and the own vehicle 130 after T seconds, that is,
The calculated inter-vehicle distance is obtained (step S8a).

Next, the difference Lp (Lp = Dp-D) between the predicted position difference (also referred to as predicted inter-vehicle distance) Dp and the target inter-vehicle distance L.
L) is obtained (step S8b).

The difference Lp is multiplied by the position gain constant Kp to obtain Lp · Kp (step S8c).

Similarly, a predicted speed difference Dv (Dv = Vbt−Va) between the vehicle 110 before prediction and the own vehicle 130 after T seconds.
t) is obtained (step SS8d).

Dv · Kv is obtained by multiplying the obtained speed difference Dv after T seconds by the speed gain constant Kv (step S8).
e).

The command acceleration Ap is obtained by combining the results of step S8c and step S8e (step S8).
f). The designated acceleration Ap can be obtained by the following equation (5).

Ap = Lp · Kp + Dv · Kv (5) Next, returning to the main routine shown in FIG. 2, it is determined whether or not the obtained designated acceleration Ap is a zero value (Ap = 0) (step S 9). ).

If Ap = 0, the vehicle may continue running at the current throttle opening and brake pressure, and the process returns to step S1 without performing any processing.

If Ap ≠ 0, an integration process of converting the indicated acceleration Ap into a throttle opening amount and adding the same to the previous throttle opening amount is performed (step S10), and the throttle CBW 15 is determined by the value of the integration result. Control is performed to increase or decrease the vehicle speed.

On the other hand, the designated acceleration Ap is also input in parallel to the brake control processing. An integration process of converting the commanded acceleration Ap into a brake pressure and adding the same to the previous brake pressure is performed (step S12), and the boost pressure control brake 16 is controlled based on the value of the integration result to apply a brake or release the brake. (Step S1
3).

Incidentally, the duty of the control pulse is normally calculated for controlling the throttle CBW 15 and boost pressure control.

In any control, the control using the integration process (integration means) is performed in order to avoid a sudden change in the designated acceleration Ap due to a missing data or the like in advance. In other words, this is because the following control of the preceding vehicle 110 is smoothly performed by making the speed change gradual.

It is preferable that the processing in steps S10 and S11 and the processing in steps S12 and S13 are performed in parallel to improve processing speed.

By performing the above-described vehicle speed control process, the following vehicle 130 can run smoothly while maintaining a substantially target inter-vehicle distance (usually a constant inter-vehicle distance) L with respect to the preceding vehicle 110. .

In this case, the speed of the following vehicle 130 may be calculated based on the position information obtained by the wheel pulse sensor 8, and the acceleration of the following vehicle 130 may be obtained using the longitudinal acceleration sensor 9. It is also possible to check at any time. Further, the target inter-vehicle distance L can be checked at any time using the laser radar 10.

Under the control of the control plan module 2, the speed of the own vehicle 130, the speed of the preceding vehicle 110, the speed of the own vehicle 1 according to the default condition or according to the instruction of the passenger.
The speed difference between the vehicle 30 and the preceding vehicle 110, the actual inter-vehicle distance, the target inter-vehicle distance, the difference between the actual inter-vehicle distance and the target inter-vehicle distance,
Necessary items can be output from the speaker via the audio output device 17, and the positions of the own vehicle 130 and the preceding vehicle 110 can be displayed on a map of the display device 18.

The above description is based on A.I. This is an explanation of the vehicle speed control processing of the following vehicle 130. The steering (steering) control process of the following vehicle 130 will be described based on the flowchart shown in FIG. 4 and the operation explanatory diagram shown in FIG.

In FIG. 5, reference numeral Xa denotes the above-described current position coordinates of the following vehicle 130 (hereinafter, the coordinates are also referred to as points for easy understanding of the invention), and reference numeral Xb denotes the above-mentioned preceding vehicle 110. The current position coordinate, symbol Xb _-1 is the position coordinate of the preceding vehicle 110 unit time before (at the time of the last GPS measurement),
The symbol Xb- _n is the position coordinates of the preceding vehicle 110 measured n times before (the number of times of GPS measurement), and the symbol Xc is the preceding vehicle 110 obtained by interpolating the position coordinate sequence Xb- _n of the preceding vehicle 110. The above-mentioned traveling locus data (also referred to as a traveling locus sequence or a preceding vehicle traveling route), a symbol Xd is a point obtained by lowering the perpendicular from the current position coordinates Xa toward the traveling locus Xc, and a symbol Xdt is a current point from the perpendicular point Xd. The predicted position when the vehicle travels at the vehicle speed Va for T seconds, the symbol Rn is the radius of curvature of the travel locus Xc at the travel position Xdt after T seconds. As described below, these values obtained or calculated from the various devices are transferred from the control planning module 2 to the lateral control module 3
Supplied to

Therefore, first, the lateral direction (steering) control module 3 receives the traveling locus Xc of the preceding vehicle 110 from the control planning module 2 and stores it (step S21).

Next, the current position coordinates Xa are received from the control planning module 2, the perpendicular is drawn to the stored traveling locus Xc, and the lateral displacement error εy of the preceding vehicle 110 from the traveling route Xc is calculated ( Step S22).

Next, an angle difference between the traveling direction Q of the vehicle 130 and the tangent direction of the preceding vehicle traveling route Xc at the point (position) Xd at which the perpendicular is lowered is calculated to calculate the angle error εθ (step S23). ). The traveling direction of the vehicle 130 can be calculated by, for example, a time integration process of a yaw rate (a time change value of a yaw angle) which is an output signal of the yaw rate sensor 5.

Also, it can be obtained as a direction connecting the current position coordinates of the self-propelled position and the previous self-propelled position coordinates.

Next, the curvature 1 / of the traveling route Xc at the point Xdt to be passed after T seconds from the current traveling position Xa.
Rn (Rn is a radius of curvature) is obtained (step S24).
In this case, the curvature 1 / Rn is determined by the following vehicle 130 at the current vehicle speed Va from the point Xd perpendicular to the current position Xa.
Xdt (Xdt = Xd + Va ×)
T) is obtained, and the curvature 1 / Rn can be obtained from the traveling locus data Xc before and after the obtained position Xdt.

Next, the (instruction) steering angle (steering angle) δ is determined by equation (5) (step S25).

Δ = F ₁ (Va, 1 / Rn) × εy + F ₂ (Va, 1 / Rn) × εθ (5) In equation (5), the feedback functions (feedback coefficients) F ₁ and F ₂ are Vehicle speed Va and curvature 1 / Rn
Various examples are obtained by experiments, and stored in the horizontal control module 3 as a look-up table or a function expression.

For example, the following equation (6) has been experimentally obtained as an example of a function equation of the steering angle δ.

Δ = ｛(K ₁ / Va) × (1 + K ₂ / Rn)｝ εy + ｛(K ₃ / Va) × (1 + K ₄ / Rn)｝ ε θ (6) where K _{1 to} K ₄ Is determined by the specifications and characteristics of each vehicle, and can be determined experimentally, for example. It can also be obtained by simulation based on experiments.

The EPS based on the indicated steering angle δ
14 are generated and controlled (step S2).
6).

As described above, according to the above-described embodiment, the preceding vehicle 110 uses the position data of the own vehicle (preceding vehicle) 110 as G
It is obtained by the PS module 112 and is transmitted from time to time by the transmitter 118 to the following vehicle 130 by the transmission antenna 119 by radio waves. The following vehicle 130 creates traveling trajectory data Xc having the address of the satellite radio wave reception time at the GPS module 112 of the preceding vehicle 110 as an address based on the position data. Based on the vehicle information (current traveling direction Q of the own vehicle, own vehicle position Xa, own vehicle speed Va), the speed of the own vehicle to be set and the steering angle are controlled. With such a very simple configuration,
The following vehicle 130 can travel along the traveling locus of the preceding vehicle 110, for example, following a certain inter-vehicle distance.

In this embodiment, a video camera for capturing the leading vehicle 110 is not required, so that a video data processing system that requires extremely high-speed processing is not required. Further, a road on which a magnetic marker is laid as infrastructure for detecting the current positions of the leading vehicle 110 and the following vehicle 130 is not required.

It should be noted that the present invention is not limited to the above-described embodiment, but can adopt various configurations without departing from the gist of the present invention.

[0068]

As described above, according to the present invention, the self-vehicle, that is, the self-following vehicle can automatically follow the traveling locus data based on the traveling locus data of the preceding vehicle received by the receiver. This achieves an effect that an automatic following vehicle can be manufactured with a simple configuration and at low cost.

In this case, the preceding vehicle is not an autonomous vehicle,
The present invention can be applied to a conventional automobile driven by a human.

Further, according to the present invention, a video camera or a road on which a magnetic marker is laid as an infrastructure is not required, and the configuration of the automatic tracking system is extremely simplified.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of the present invention.

FIG. 2 is a flowchart of a main routine used for explaining a vehicle speed control process in the example of FIG. 1;

FIG. 3 is a flowchart of a subroutine related to an instruction acceleration calculation process in the flowchart of FIG. 2;

FIG. 4 is a flowchart provided for explaining a steering control process in the example of FIG. 1;

FIG. 5 is a diagram used for explaining a steering control process in the example of FIG. 1;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Communication module 2 ... Control planning module 3 ... Lateral direction control module 4 ... Vehicle speed control module 6, 112 ... GPS module 100 ... Automatic tracking system 110 ... Front running vehicle 118 ... Transmitter 130 ... Tracking vehicle A ... Running direction Xa ... Following vehicle current position Xb: Previous vehicle current position Xc: Previous vehicle traveling trajectory Xd: Vertical line down position Xdt: Position after T seconds

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI B62D 101: 00 103: 00 137: 00

Claims (4)

[Claims] 1. A receiver for receiving travel trajectory data of a preceding vehicle from the preceding vehicle, and control plan creating means for creating a plan of a vehicle speed and a steering angle of the own vehicle based on the received travel trajectory data. An automatic following vehicle, comprising: an actuator that controls a vehicle speed and a steering angle of the own vehicle according to a created plan. 2. A preceding vehicle which calculates two-dimensional position data of its own vehicle by a two-dimensional position calculating means, and transmits the calculated two-dimensional position data to a following vehicle by a transmitter, and the transmitted two-dimensional position data. And a follower vehicle that performs automatic driving control to advance the position of the own vehicle to the two-dimensional position indicated by the two-dimensional position data based on the received two-dimensional position data. Automatic tracking system. 3. A vehicle comprising a preceding vehicle and a following vehicle running following the preceding vehicle, wherein the preceding vehicle is equipped with a two-dimensional position calculating means for calculating a two-dimensional position of the own vehicle and a transmitter, The following vehicle is equipped with a two-dimensional position calculating means for calculating a two-dimensional position of the own vehicle, a receiver, and a following travel control means, and the preceding vehicle is calculated by the two-dimensional position calculating means of the own vehicle. The transmitter transmits the two-dimensional position data of the own vehicle to the following vehicle by the transmitter, and the following vehicle includes two-dimensional position data of the own vehicle calculated by the two-dimensional position calculating unit. Two-dimensional position indicated by the two-dimensional position data received from the preceding vehicle while maintaining a fixed inter-vehicle distance based on the preceding vehicle two-dimensional position data transmitted from the preceding vehicle and received by the receiver. Automatic driving control to advance the position of the own vehicle An automatic following system characterized by the following. 4. The automatic tracking system according to claim 2, wherein said two-dimensional position calculating means is a means including a GPS receiver.