JP2000177428A - Method and system for controlling vehicle running - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain a fixed point and on-time stopping and to improve convergence and comfortableness. SOLUTION: A target position to time is fixed in advance. The quantity of status indicating a positional deviation between the target position and an actual running position is obtained. Vehicle speed is feedback-controlled so that the quantity of status may be small. Preferably, the target position S (t) to time and target vehicle speed v (t) are computed (S30). The quantity X (t) of status computed by S4 includes a deviation x1 (t) between the target position and the double-position of an actual vehicle, a deviation x2 (t) between target vehicle speed and actual vehicle speed, and position deviation integration x3 (t). LQ control is applied to obtain the quantity u (t) of system input from the quantity X (t) of status and feedback gain K (S42).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method and a system for automatically driving a vehicle according to a predetermined target.

[0002]

2. Description of the Related Art In recent years, an autonomous vehicle that can be applied to a new transportation system has attracted attention. This type of vehicle, for example,
Under the automatic steering control and the automatic speed control, the vehicle can travel on a predetermined course, and can travel in a platoon without mechanical connection. Such a system has the advantages that the formation is flexible, the infrastructure can be made relatively inexpensively, and the vehicles can be provided relatively inexpensively. Therefore, it is expected that the present invention can be applied to traffic between terminals in an airport, intercity traffic, and other traffic systems.

[0003]

SUMMARY OF THE INVENTION The inventor of the present invention has filed a Japanese patent application (Japanese Patent Laid-Open No. Hei 10-287221).
It discloses that a vehicle speed is feedback-controlled by PID control for an autonomous vehicle traveling on a predetermined track (course).

[0004] PID control is performed using a map of a target speed with respect to a position on a trajectory. In the example of FIG. 10, the horizontal axis is the position, and the vertical axis is the target speed. The target speed v (S) is calculated from the vehicle traveling position S using such a map. The actual vehicle speed is controlled to match the target value v (S) using the derivative term, the integral term, and the proportional term.

[0005] In PID control, speed control with respect to position is suitably performed. Therefore, it is suitable for control that stops the vehicle at a fixed position on the course (speed 0) (fixed point stop).

However, the target speed v which is a control parameter is
(S) does not include time, and the ability to follow the target value in a quick period during control is low. Therefore, the position cannot be controlled with respect to time, and it is not suitable for control for stopping the vehicle at a fixed position at a fixed time (fixed point, fixed stop).

[0007] For example, it is assumed that a plurality of vehicles run in a row and each vehicle in the row is independently controlled. PID
In this case, since the vehicle position cannot be controlled at each time, the inter-vehicle distance may vary, which may cause disturbance of the platoon.

For reference, so-called “mimic control”
Although platooning is realized by mimicking the acceleration / deceleration operation of a preceding vehicle, it is difficult to be adapted to a system that requires independent control of each vehicle.

It is an object of the present invention to solve the above problems and to provide a vehicle traveling control method and system suitable for platooning.

[0010]

According to the present invention, a target position with respect to time is determined in advance. Then, a state quantity representing a positional deviation between the target position and the actual traveling position is obtained. Then, the vehicle speed is feedback-controlled so that the state quantity is reduced. This allows
Control of the vehicle position with respect to time becomes possible. For example, in deceleration stop control, the vehicle can be stopped at a fixed position at a fixed time.

[0011] Preferably, the control of the present invention uses the LQ control law. Compared to the PID control, in which the magnitude of the control gain is limited in order to avoid divergence of the control, the LQ control can quickly converge to the target value by the high gain control. In addition, the LQ control has a good ability to follow the target value,
Therefore, for example, when the present invention is applied to deceleration control, deceleration at a substantially constant deceleration is possible, and jerk (differentiation of acceleration; index of riding comfort) is small. Therefore, the ride comfort of the vehicle can be improved in addition to the speed of convergence. In this way, it is possible to appropriately set the gain, and control suitability is improved.

Preferably, the state quantity for LQ control is:
In addition to the above-described position deviation, it includes a speed deviation between the target speed and the actual speed with respect to time, and further includes a position deviation integral which is an integral value of the position deviation. By using the position deviation integration, the accuracy of the vehicle stop position can be increased.

Preferably, when the present invention is applied to a platooning system, when a control error of a preceding vehicle during platooning becomes larger than a predetermined value, a target position of the own vehicle with respect to time is redefined. The vehicle travel is controlled based on the redefined target position. According to this aspect, when there is a vehicle in which an error has occurred, it is possible to quickly change the target value of the following vehicle. Therefore, smoother platooning can be realized without disturbing the platoon.

Although the deceleration and stop control has been mainly described here, it goes without saying that the present invention is similarly applicable to acceleration control and constant speed control.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention (hereinafter, referred to as embodiments) will be described below with reference to the drawings.

First, the principle of the control according to the present invention will be described. Although the deceleration control is described here, the present invention can be similarly applied to control other than the deceleration mode, that is, acceleration control and constant speed control.

An object of the present invention is to provide a control method and system capable of performing position control with respect to time and realizing a fixed point / on-time stop. In order to achieve this object, the present invention, as shown in FIG.
It is proposed to define a target position S (t) (vertical axis) for. In FIG. 1, the position from the start of braking to the stop of the vehicle is defined. The vehicle speed is controlled so that the actual vehicle position converges to the target position S (t).

In particular, the present invention proposes to make it possible to apply the LQ control law to vehicle speed control by incorporating the following measures. LQ control refers to linear quadratic optimal control.
mal control).

FIG. 2 shows the target vehicle speed v (t) derived from the target position S (t) in FIG. It is preferable that the target position S (t) and the target vehicle speed v (t) are set in advance and stored in a vehicle control ECU or the like. The actual vehicle position is r (t), and the actual vehicle speed is r '(t).

From these numerical values, the following state quantity X (t) is calculated as a control parameter for fixed point / timed stop. Here, x1 (t) is a position deviation (deviation between the target position and the detected actual position; position error), and x2 (t) is x2 (t).
(T) is a speed deviation (deviation between target speed and actual speed; speed error). Further, x3 (t) is an integral value of the position deviation x1 (t).

[0021]

X (t) = (x1 (t), x2 (t), x3 (t))

X1 (t) = S (t) -r (t)

X2 (t) = v (t) -r '(t)

X3 (t) = ∫ (S (t) −r (t)) dt Using the state quantity X (t), the state equation of the vehicle traveling can be written as follows. Here, m is a vehicle mass, and u (t) is a system input amount. The third term on the right side is a feedforward term. If the control target has been achieved, a deceleration r ″ (t) occurs.

[0022]

(Equation 6) This equation is a general equation of state for LQ control (X ′ (t)
= AX (t) + Bu (t)). The determinants and dimensions are properly set and arranged so that when the right side is calculated, the terms related to distance, velocity, and distance integration are correctly derived. Therefore, if this state equation proposed by the present invention is used, LQ control can be applied to automatic vehicle traveling.

Therefore, the state feedback gain K is calculated by the Riccati equation by applying the optimal control problem based on the above state equation. The gain K is preferably calculated in advance and stored in the vehicle control ECU. During the control, the state quantity X (t) and the gain K are calculated according to the following equation.
From the system input amount u (t).

[0024]

U (t) = − K × X (t) The dimension of u (t) is acceleration / deceleration (differentiation of speed). The deceleration control is performed using u (t). For example, when the reduction gear is a hydraulic friction brake, the command oil pressure P is set to P = f
(U (t)), and the command oil pressure P is generated in the brake system.

The above is the basic principle of the vehicle speed control according to the present invention. According to the present invention, the target position shown in FIG. 1 is determined, and the vehicle speed is feedback-controlled so that the deviation between the target position and the actual traveling position is reduced. Therefore, it is possible to control the position with respect to time, and it is also possible to realize a fixed point and a fixed stop. Automatic traveling control, such as moving from station to station and stopping accurately at the stop position of the next station on time becomes possible.

Further, according to the present invention, it is possible to incorporate LQ control into automatic driving. In the PID control, a great deal of trouble is required for gain adjustment to realize position control with respect to time, but such control can be easily realized in the LQ control. This means that the present invention has made it possible to realize efficient and highly accurate "position control with respect to time" by realizing the introduction of LQ control into the running of an automatic vehicle.

In PID control, the magnitude of the control gain is limited in order to avoid divergence of the control. Compared with the PID control, the LQ control enables high gain control, and converges faster. Furthermore, since the target value can be easily followed, deceleration at a substantially constant deceleration (G) is possible, and jerk (differentiation of acceleration; index of riding comfort) is small. Therefore, the riding comfort of the vehicle can be improved.

Further, in the LQ control of the present invention, the position error integral x3
(T) is included in the control parameters. Thus, the present invention realizes control according to the LQI control theory. Then, the control for reducing the position deviation integral x3 (t) can reduce the steady-state deviation.

However, a configuration in which the position deviation integral is not included in the control parameters is also possible within the scope of the present invention. That is, it is also possible to use the position deviation and the speed deviation as state quantities and perform LQ control based on a state equation related to the state quantities. More specifically, a state equation in which an element relating to the position deviation integral x3 (t) is deleted from the above-described state equation may be used. Even with such a configuration, position control with respect to time can be realized, and high convergence and good riding comfort can be obtained.

The present invention is suitably used as a control algorithm for vehicles running in platoon. When a plurality of vehicles automatically travel with a small inter-vehicle distance, high-precision position control is necessary in order to maintain a positional relationship with preceding and following vehicles. According to the present invention, since the control of the vehicle traveling position with respect to the time is performed with a small delay and an error, the platooning is favorably performed.

The present invention can be applied to acceleration control and steady speed control in a similar manner, in addition to deceleration control. That is, a configuration in which the present invention is applied to one of acceleration, constant speed, and deceleration modes and a configuration in which the present invention is applied to two or more modes are included in the technical scope of the present invention.

For example, when the system input amount u (t) is calculated, in a place where the value of u (t) is positive, u (t) is converted into an accelerator instruction, and the prime mover is controlled to increase the vehicle speed. On the other hand, in a place where the value of u (t) is negative, u (t) is converted into a brake instruction and deceleration is performed.

Next, an example of a model of a vehicle traveling control system to which the present invention is applied will be described with reference to FIGS.

Referring to FIG. 3, as a roadside system (infrastructure), a course 1 on which a vehicle should travel is predetermined. On the course 1, there are provided A station and B station where the vehicle should stop. Top car (1
(Car No.), Car No. 2 and Car No. 3 are at fixed positions at Station A. These vehicles form a platoon and move from station to station and stop at a fixed location at station B.
Move from station to station A. Magnetic nails (not shown) are provided on the course 1 at equal intervals (for example, 1 m). Further, a deceleration instruction marker 3 is provided a predetermined distance before the A station and the B station.

FIG. 4 shows a system configuration on the vehicle side. A signal indicating the vehicle running state is input to the vehicle control ECU 10 from each of the sensors 12 to 14. Wheel speed sensor 1
2 detects the rotation speed of the wheel. The magnetic sensor 14 detects a magnetic nail on a road. The inter-vehicle distance sensor 16 is, for example, a radar device or a camera, and detects an inter-vehicle distance from a preceding vehicle.

The vehicle control ECU 10 includes a wheel speed sensor 12
Then, the position r (t) and the speed r ′ (t) of the vehicle are calculated using the input signal from the magnetic sensor 14 together. Specifically, the position and speed of the vehicle are calculated based on the wheel speed sensor 12. Then, the calculation result is transmitted to the magnetic sensor 14.
Is corrected using the detection signal from

The vehicle control ECU 10 uses the communication device 18 to exchange vehicle position and speed information with another vehicle. By using this exchange information, the states of the preceding vehicle and the following vehicle can be known, and the inter-vehicle distance can also be known.
The inter-vehicle distance sensor 16 is used for auxiliary purposes such as collision avoidance.

The vehicle control ECU 10 is a steering ECU.
A control signal is sent to the ECU 20 and steering control is performed by both ECUs. Here, the direction in which the vehicle should travel is determined based on the magnetic nail detection signal. A target traveling direction required for the vehicle to travel without departing from the line connecting the magnetic nails is obtained. The steering actuator 22 is controlled so that the target traveling direction is achieved, and the wheels 23 are steered. The vehicle travels while tracing a line connecting the magnetic nails.

Further, the vehicle control ECU 10 controls the engine E
A control signal is sent to the CU 24 and the brake ECU 28,
Speed control is performed by these ECUs. Engine E
The CU 24 controls the output of the engine 26 to accelerate the vehicle. The brake ECU 28 controls the brake actuator 30 to operate the hydraulic friction brake 32,
Slow down the vehicle. The vehicle accelerates after leaving the station,
Then, the vehicle shifts to constant speed traveling. When the deceleration instruction marker 3 is detected, deceleration control is started and stops at a predetermined position of the next station. The deceleration instruction marker 3 is detected using the magnetic sensor 14 or another sensor.

Here, the present invention is applied to the control of the deceleration portion, and the control processing is shown in FIG. Prior to the start of the vehicle, the state feedback gain K is calculated by the Riccati equation (S10). An appropriate gain K is required so that the balance between the deviation and the system input is good, the input amount does not become too large, and a rapid change in the input is suppressed. The gain K is calculated in advance and stored in a memory (such as a ROM) in the vehicle control ECU 10, and this gain K is used for subsequent control.

When the vehicle starts (S12), it is determined at every predetermined control cycle whether a deceleration instruction marker on the course has been detected (S14), and if not detected, the timer T is set to 0 (S16). .

When the deceleration instruction marker is detected, the timer counts up (T = T + 1) (S18). Then, a target position S (t) and a target vehicle speed v (t) with respect to the current time T are calculated (S30). Preferably, the maps shown in FIGS. 1 and 2 are prepared in advance, and the vehicle control ECU 10
Stored in memory. The target value may be read from this map.

Further, a state quantity X (t) is calculated using the actual vehicle position r (t) and the actual vehicle speed r '(t) obtained from the sensor detection signal (S40). As mentioned above, X
(T) is a position deviation x1 (t), a speed deviation x2 (t),
Includes position deviation integral x3 (t). And the state quantity X
The control input u (t) is calculated from (t) and the gain K (S
42).

From the control input u (t), P (t) = f (u
(T)), the target oil pressure (instruction oil pressure) of the brake device
Is obtained (S44). f represents an appropriate function. Referring to the equation of state, the target deceleration is obtained from u (t) / m and r ″ (t). Since the deceleration and the brake oil pressure correspond to each other, an appropriate target brake oil pressure P for achieving the target deceleration is obtained. It is preferable to prepare a map representing the relationship between deceleration and brake oil pressure, and read the oil pressure from this map.

Then, the brake actuator is controlled so that the brake oil pressure P (t) calculated in S44 is generated (S46). It is determined whether the actual vehicle speed r (t) has become 0 (S48), and if NO, the process returns to S18. If S48 is YES, the vehicle travels according to the target position line (FIG. 1), and finally stops at the next station at a fixed point / on time, thus ending the control.

The present embodiment can of course be arbitrarily modified within the scope of the present invention. For example, in the present embodiment, the present invention is applied to a vehicle equipped with an engine (internal combustion engine). However, the present invention may be applied to any other type of vehicle, for example, an electric vehicle, a hybrid vehicle, a train, and the like.

Although the automatic steering is performed in the present embodiment, the vehicle may be guided by rails or the like and run.

In this embodiment, the vehicle position and the vehicle speed are detected by using the wheel speed sensor and the magnetic sensor (magnetic nail detection). However, the position and the speed may be detected by using any other method.

Further, in the present embodiment, the friction brake is controlled at the time of deceleration, but any other reduction gear may be used. In particular, it is preferable to use a motor brake such as an engine brake or a motor regenerative braking alone or in combination with a friction brake from the viewpoint of energy efficiency.

"Correction for Control Error of Own Car" Next, referring to FIGS. 6 and 7, a correction function when an error occurs in control of the own car will be described.

When the present invention is applied to an actual system,
A large control error may occur due to a disturbance such as a strong wind. Therefore, as shown in FIG. 6, an allowable limit e (t) of the control error is defined. E (t) is set above and below S (t), respectively.

As described above, the deviation between the target position S (t) and the actual vehicle position r (t) is x1 (t) = S (t) -r
(T). As shown in the example of FIG. 6, S (t) and r
(T) is separated, the positional deviation x1 (t) increases, and at time t0, x1 (t0) becomes larger than e (t0).

At this time, the target position is redefined (FIG. 6, SR (t)). Here, SR (t) is (t0, S
0) and (T, S (T)). S0
Is the actual vehicle position at time t0, and T is the target stop time.

Using the target position SR (t), the target vehicle speed is also redefined (vR (t) = SR '(t)). Then, using these target values, the state quantity is calculated, and the subsequent control is performed.

FIG. 7 shows the above control. S
Steps 10 to S30 are the same as the steps denoted by the same reference numerals in FIG. FIG. 7 shows S32 and S34.
Has been added. In S32, the position deviation x1 (t)
Is compared with the control error limit e (t). e (t) ≧ |
If x1 (t) |, the process proceeds to S40. However, if e (t) <| x1 (t) |, the process proceeds to S34, and the target position and the target speed are redefined as described with reference to FIG. Then, S (t) = SR (t), v
(T) = vR (t), and the process proceeds to S40. The processing after S40 is the same as the processing in FIG.

By the above processing, even if an error occurs in the control of the own vehicle, appropriate correction can be made, and the fixed point and timed stop functions can be maintained.

Assuming that the inter-vehicle distance of the platoon is about 10 m, e (t) is, for example, about 1 m. The present embodiment is suitably applied to such high-precision control.

"Correction for control error of preceding vehicle"
With reference to FIGS. 8 and 9, a further improved embodiment capable of correcting an error in the control of the preceding vehicle will be described.

When the present invention is applied to an actual system,
Even if the control of the own vehicle is performed accurately, if an error occurs in the control of the preceding vehicle, the inter-vehicle distance deviates from the plan and the platoon is disturbed. In order to ensure smooth operation of the transportation system, it is desirable to avoid disruption of the platoon. Therefore, in the present embodiment, the following control is performed.

Referring to the example of FIG. 8, 3
Each of the vehicles (No. 1 to 3) has target positions S1 (t), S2 (t), and S3 (t) with respect to time. The position of the first car at the start of braking is set to S1 (0) = 0. t ≦ 0, that is, the inter-vehicle distance while traveling at a steady speed is 1
It is set to 0 m, and the steady running speed is 35 km / h (not shown). The inter-vehicle distance at the time of stop (t = 20) is set to 1 m.

If all vehicles can travel according to the target position,
The inter-vehicle distance gradually decreases from 10m to 1m. However, if a control error occurs in one vehicle due to factors such as disturbance,
The distance between the vehicle and the following vehicle is reduced.

In order to cope with such a case, in the present embodiment, an allowable lower limit value ed (t) of the inter-vehicle distance to the preceding vehicle is set as follows (assumed danger inter-vehicle distance).

The following description focuses on the first and second cars. The target inter-vehicle distance d (t) at time t is d
(T) = S1 (t) -S2 (t). This d
In consideration of (t), the lower limit inter-vehicle distance ed (t) is set as shown by a dotted line in the example of FIG. In the present embodiment, ed (t) = k using an appropriately determined lower limit setting coefficient k.
-It is defined as d (t0).

On the other hand, the actual inter-vehicle distance dr (t) is r 1
(T) -r2 (t). During braking control, dr (t)
Is compared with the lower limit inter-vehicle distance ed (t). And dr
When (t) falls below the lower limit inter-vehicle distance ed (t), the target position of the following vehicle is redefined. In the redefinition, a target position with respect to time is determined so that the inter-vehicle distance quickly becomes sufficiently large and a stop point can be reached on time in subsequent traveling.

In the example of FIG. 8, the control of the second car is basically accurate, but as a result of the occurrence of an error in the control of the first car, the time t
At 1, the actual inter-vehicle distance dr (t) has reached the lower limit inter-vehicle distance ed (t). At this time, the target position of the second car is redefined (SRR (t)). SRR (t) is set so that the inter-vehicle distance recovers to the target value (d (t1 + ΔtR)) in a predetermined time ΔtR. Further, at the stop time T, the stop position S
A curve from t1 + ΔtR to T is set so that (T) can be reached. Time t = t1, t = t1 + Δt
In R, the target position line before and after is smoothly connected by a curve in order to prevent the occurrence of a shock.

Further, the target vehicle speed is redefined using the target position SRR (t) (vRR (t) = SRR '(t)). Then, using these target values, the state quantity is calculated, and the subsequent control is performed. As a result, the inter-vehicle distance is restored, and the disturbance of the platoon is quickly eliminated.

In the example shown in FIG. 8, the first car has a function of correcting the control error of the own car. Therefore, when the control error reaches a predetermined value, the first car redefines its own target position.

The third car also has the same correction function as the second car. Therefore, when a control error of the second car as a preceding vehicle occurs, the target position of the third car is redefined.

Further, in FIG. 8, the inter-vehicle distance between the second car and the third car may fall below the lower limit value due to the redefinition of the target position of the second car. In this case, the target position of the third car is also redefined.

FIG. 9 shows the above control process in a generalized manner. The steps S10 to S18 are the same as the steps denoted by the same reference numerals in FIGS. FIG.
20 and S22 have been added. In S20, the actual inter-vehicle distance dr (t) is compared with the lower limit inter-vehicle distance ed (t).

The vehicle control ECU obtains the vehicle position of the preceding vehicle using the communication device. The actual inter-vehicle distance is calculated from the positions of the preceding vehicle and the own vehicle. In addition, the vehicle control ECU
The target position S1 (t) of the preceding vehicle is acquired using the communication device. Therefore, the target inter-vehicle distance is known, and the lower limit value ed (t) = k · d (t) is calculated from the target value.

In S20, dr (t) ≧ ed (t)
If so, the process proceeds to S30. However, dr (t)
If <ed (t), the process proceeds to S22, and the target position and the target speed are redefined as described with reference to FIG.
That is, the target position is redefined so that the inter-vehicle distance quickly increases in the predetermined time ΔtR, and thereafter, the initially set fixed point and timed stop can be performed (SRR (t)). Then, S (t) = SRR (t), v (t) = vRR (t), and the process proceeds to S30. The processing after S30 is the same as the processing in FIG.

By the above processing, even if an error occurs in the control of the preceding vehicle, an appropriate correction can be made. And
In addition to maintaining the fixed point and scheduled stop functions, the platoon can be prevented from being disturbed, and smooth operation of the platoon can be ensured.

Although it is preferable to use the communication device as a part of the inter-vehicle distance detecting means as in this embodiment, the inter-vehicle distance may be detected by another arbitrary method. The inter-vehicle distance may be detected by a sensor.

[Setting of State Feedback Gain K] Finally, a method of setting the state feedback gain K used in the control of the present invention will be described. The gain K may be derived in accordance with a well-known LQ control rule. For example, LQ control is disclosed in “Systems and Controls” (Shigeyuki Hosoe, Ohmsha, 1st edition, p. 97-). State.

Consider the following equation of state: X (t) is n
Dimensional state vector, u (t) is an m-dimensional control vector,
A and B are n × n and n × m constant matrices.

[0077]

X '(t) = AX (t) + Bu (t) Then, a state feedback control law u (t) =-K.X (t) that minimizes the following evaluation function J (X0) is obtained. . Q and R are constant matrices each having an appropriate dimension.

[0078]

(Equation 9) To find a solution to this problem, consider an algebraic equation for a target matrix P of order n × n. This is Riccati (Ricc)
ati) called the equation.

[0079]

(Equation 10) further,

[Equation 11] far. The feedback gain K that satisfies the state equation and minimizes the evaluation function is given above.

In the case of this embodiment, X in the equation of state
(T) is (x1 (t), x2 (t), x
3 (t)). x1 (t), x2 (t), x3
(T) is a position deviation, a speed deviation, and a position deviation integral, respectively. A and B are the following matrices, respectively.
Here, m is the vehicle weight.

[0081]

(Equation 12) A and B are physically determined from the relationship between the left side and the right side according to the state variable X. On the other hand, R and Q in the evaluation function are obtained as a result of trial and error by a control simulation and an actual vehicle test. For example, the following values are adopted for R and Q.

[0082]

(Equation 13) K obtained using these values is as follows. This K is stored in the control device and used for traveling control.

[0083]

K = [4503,6157,98]

As described above, according to the present invention, it is possible to control the traveling position of the vehicle with respect to time, and it is possible to realize a favorable traveling operation including a fixed point and a fixed stop. Further, since LQ control can be applied, it is possible to achieve both convergence and ride comfort. Furthermore, there is an advantage that a smooth platooning can be ensured.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a definition example of “target vehicle position with respect to time” used for control of the present invention.

FIG. 2 is a block diagram showing a definition example of “target vehicle speed with respect to time” used for control of the present invention.

FIG. 3 is a diagram showing a configuration on a road side of the traffic system according to the embodiment of the present invention.

FIG. 4 is a diagram showing a configuration of a vehicle-mounted device of the transportation system according to the embodiment of the present invention.

FIG. 5 is a flowchart showing deceleration control to which the present invention is applied in the system of FIG. 4;

FIG. 6 is a diagram illustrating a correction process when an error occurs in control of the own vehicle.

FIG. 7 is a control flowchart to which the processing of FIG. 6 is applied.

FIG. 8 is a diagram illustrating a correction process when an error occurs in control of a preceding vehicle during platooning.

FIG. 9 is a control flowchart to which the processing of FIG. 8 is applied.

FIG. 10 is a diagram showing a "map of target speed with respect to position" for PID control used in conventional automatic traveling control.

[Explanation of symbols]

Reference Signs List 10 vehicle control ECU, 12 wheel speed sensor, 14 magnetic sensor, 18 communication device, 28 brake ECU, 3
0 Brake actuator.

Claims (9)

[Claims] 1. A vehicle running control method for automatically running a vehicle according to a predetermined target, comprising: determining a target position with respect to time in advance; obtaining a state quantity representing a positional deviation between the target position and an actual running position; A vehicle traveling control method, wherein the vehicle speed is feedback-controlled so that the state quantity is reduced. 2. The vehicle travel control method according to claim 1, wherein an LQ control law is used. 3. The vehicle travel control method according to claim 2, wherein the state quantity further includes a speed deviation between a target speed and an actual speed with respect to time. 4. The vehicle travel control method according to claim 3, wherein the state quantity further includes a position deviation integral which is an integral value of the position deviation. 5. The vehicle traveling control method according to claim 4, wherein a state quantity including the position deviation, the velocity deviation, and the position deviation integration, and a state obtained using a Riccati equation based on a state equation including the state quantity. A vehicle travel control method comprising: controlling a vehicle speed using a control input calculated using a feedback gain. 6. The vehicle travel control method according to claim 4, wherein the position deviation x1 (t), the speed deviation x2 (t), the position deviation integral x3 (t), the vehicle mass parameter m, the system input amount u (t ), The following equation of state expressed using the feedforward element r ″ (t): A vehicle driving control method characterized by applying an LQ control law to the vehicle. 7. The vehicle traveling control method according to claim 1, wherein when a control error of a preceding vehicle during platooning becomes larger than a predetermined value, a target position of the own vehicle with respect to time is reset. A vehicle travel control method comprising: controlling a vehicle travel based on a defined and redefined target position. 8. The vehicle travel control method according to claim 7, wherein the redefinition is performed when an inter-vehicle distance to a preceding vehicle becomes smaller than a predetermined value. 9. A vehicle traveling control system for automatically traveling a vehicle according to a predetermined target, comprising: a target position acquiring means for acquiring a target position with respect to a predetermined time; Vehicle traveling, comprising: position acquisition means; and speed control means for performing feedback control of the vehicle speed based on a state quantity representing a deviation between the target position and the actual traveling position so as to reduce the state quantity. Control system.