JPH0785608B2 - Vehicle automatic control method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic vehicle control method, and in particular, a vehicle driven by a discrete control input such as a notch is stopped at a stop target point without frequently changing a control command. The present invention relates to an automatic control method of a vehicle that enables the operation.

[Prior art]

FIG. 1 is a block diagram showing an example of a conventional automatic train control device for automatically stopping a train at a target position, and FIG. 2 is an operation explanatory diagram showing its speed pattern. In FIG. 1, 1 is a speed generator, 2 is a speed calculation circuit, 3 is a distance integration circuit, 4 is a ground element, 5 is a point detector, 6 is a pattern generator, 7 is a comparator, and 8 is a brake controller. And 9 has shown the brake device.

In the above-mentioned conventional fixed position stop control, the vehicle uses a ground detector 4 installed at a point P (point P) located a predetermined distance l before the stop target point O (point O) as a reference, and a point detector on the vehicle. 5 to detect. The distance integration circuit 3 counts the pulses from the speed generator 1 according to the point detector detection signal from the point detector 5, and outputs the distance S traveled by the vehicle from the point P. In addition, the pattern generator 6 selects the distance l to the stop target point from its own memory in response to the point detection signal from the point detector 5, and determines the predetermined deceleration β.
_{With P} The target speed pattern V _{P according} to the following equation is output.

The speed calculation circuit 2 calculates the actual speed V _{T of the} vehicle from the pulse of the speed generator 1. The comparator 7 compares the actual speed V _T with the target speed pattern V _P output from the pattern generator 6. Based on the output signal (V _T −V _P ) of the comparator 7, the brake device 9 is comparatively controlled via the brake control device 8 so that the actual speed V _T of the vehicle follows the target speed pattern V _P. Controls to stop near the stop target point O.

However, in the method described above, the braking device 9
There is a case where the follow-up steady deviation with respect to the target speed pattern V _P occurs due to the fluctuation of the braking force and the fluctuation of the external force due to the gradient of the track, and the stop accuracy is deteriorated. Further, if integral control is performed in addition to the comparison control of the brake device 9 in order to prevent the occurrence of the following steady-state deviation, the control command (notch) is frequently changed, which causes another problem that the riding comfort of the vehicle deteriorates. Occurs.

[Object of the Invention]

The present invention has been made in view of the above circumstances, and it is an object of the present invention to realize a comfortable ride by reducing the number of changes of control commands (notches) as much as possible when stopping a vehicle at a target point. An object is to provide a vehicle automatic control method.

[General Description of Invention]

In order to achieve the above object, the present invention determines a control command according to the state of the vehicle, and in a vehicle automatic control method for performing speed control for stopping the vehicle according to the control command, the vehicle is a stop target point. After passing through the predetermined position in front, while predicting the stop error that would occur if a predetermined brake command was given at that time, check whether the vehicle has reached the state where the brake control operation should be started. The brake control start determination operation for determining is periodically performed, and after the brake control start state is reached, the determination operation of the brake control command is periodically performed according to the state of the vehicle, and the vehicle is operated according to the brake control command. The feature is that the speed control is performed.

The determination of the brake control command is performed in the case of holding the brake control command as it is and in the case of the vehicle,
For example, the distance between the current point and the stop target point, the control error predicted from the vehicle speed or acceleration, and the control error predicted when the control command is changed by a predetermined amount are compared by fuzzy inference. Depending on the result, one control command to be given to the vehicle is selected.

Example of Invention

FIG. 3 is a block diagram of a vehicle fixed position stop control device showing an embodiment of the present invention, and the same components as those shown in FIG. 1 are shown by the same reference numerals. Further, 2'is a speed / acceleration calculation device for calculating the speed (actual speed) V _T and acceleration α _T of the vehicle by the pulse of the speed generator 1 in the past 1 second, and 3'is the current position (x ₁ ) of the vehicle and the stop A remaining distance calculation device for calculating the distance L ₁ to the target point O, 10 is predetermined in correspondence with the current vehicle speed V _T , the distance L ₁ to the stop target point O and a notch selected in advance. Using the calculated deceleration β _P , L ₂ = L ₁ −V _T ² /(7.2·β _P ) ... (2) The stop error L when braking with the notch previously selected by the formula A predetermined notch stop error calculator for calculating ₂ and 11 is the stop error L ₂ and the current speed V _T
From this, the brake control start margin time ΔT when traveling at the current speed is calculated by the formula ΔT = 3.6L ₂ / V _T (3), and the margin time ΔT becomes a fixed time (for example, 1 second) or less. In this case, the brake control start command calculation device outputs a brake control start signal for stopping at a fixed position.

The 12Z, 12P, and 12N show the stop accuracy predicted when the vehicle is operated under different control commands, for example, when the notch selected in advance is held, when one notch is added, and when one notch is subtracted. A stop precision ambiguous amount calculation device for calculating a vague amount, a notch change suppressing device 13 for generating a signal M for suppressing notch change for a predetermined period after the notch change, for example, one second, and 14 for Vague inference is performed based on the output, and the notch command N should be output when notch change is not suppressed.
A control notch calculating device for calculating (t), and 15 is a brake command calculating device for connecting and disconnecting the output of the control notch calculating device 14 according to the output of the brake control start command calculating device 11.

The operation of the apparatus of this embodiment will be described below with reference to FIGS. 4 and 5.

FIG. 4 is a diagram for explaining the operation of determining the brake control start time for the fixed position stop control, in which the vehicle passes a point P located a predetermined distance 1 from the stop target point O, It shows the situation at x ₁ . The predetermined notch stop error calculation unit 10 described above, determine the stop error L _2, from between this and the current speed V _T, seeking brake start time margin ΔT by the brake control start command calculation unit 11, starts the brake A brake control start command is output when the allowance time ΔT is equal to or less than a fixed time (for example, 1 second).

FIG. 5 is a diagram for explaining the operation of selecting a brake notch for stopping at a fixed position. In the stop accuracy fuzzy amount calculation devices 12Z, 12P, 12N, the distance to the stop target point obtained by the remaining distance calculation device 3'indicating the state quantity of the vehicle.
L ₁ and the current speed calculated by the speed / acceleration calculator 2 ′
V _T1 , acceleration α _T1 and predetermined acceleration Δ per notch Δ
From α (for example, 0.5 Km / h / sec), the scalar amounts L _Z , L _P , and L _N of the stop accuracy, which is the control purpose, are calculated by the following equation (4).

Here, it is assumed that the ambiguous amount of stop accuracy is composed of two ambiguous base sets: ( ₁ ) can be stopped within a tolerance (μ ₁ ) and (2) can be accurately stopped at a stop target position (μ ₂ ). A membership function that represents these fuzzy sets is defined as follows, for example. x is the stop error (m) and the allowable error is 0.
If the distance is 5 m, the membership function μ ₁ (x) of the fuzzy platform set that can be stopped within the above tolerance is And the membership function μ ₂ (x) of the fuzzy base set that can accurately stop at the stop target position is Is defined as

The output of each of the stopping accuracy ambiguous amount computing devices 12Z, 12P, 12N is an ambiguous amount consisting of a pair of values of the above two membership functions μ ₁ (x) and μ ₂ (x) with respect to the predicted stopping accuracy. It represents. That is, from the scalar quantity L _Z , L _P , L _N of the stop accuracy, the ambiguous quantity _Z , _P of the stop accuracy when the current notch is held and when the notch is changed by ± 1 notch from the current value , _N is obtained as a value expressed as follows.

Based on the outputs _Z , _P , _N from the stop accuracy fuzzy amount computing devices 12Z, 12P, 12N, the control notch computing device 14 is, for example, as shown below, a control law (1) consisting of a condition part and a conclusion part.
Based on the ambiguous inference according to (3), a control command to be output, that is, a notch is selected.

(1) If the current notch can stop within the allowable range,
Keep the current notch.

(2) If it is possible to accurately stop at the stop target position with +1 notch, increase by 1 notch.

(3) If it is possible to accurately stop at the stop target position with -1 notch, decrease by 1 notch.

The specific notch selection based on the fuzzy reasoning is performed by selecting the value of the membership function corresponding to each condition part among the control rules (1) to (3) (in the embodiment, C _Z1 ,
This is done by selecting the one with the maximum C _P2 , C _N2 ). Note that this control is performed when there is no notch change suppression signal M from the notch change suppression device 13.

In the present embodiment, the first consideration is that the target stop point can be stopped within the allowable error, and the notch is changed only when the stop can be stopped with higher accuracy by changing the ± 1 notch. It is possible to realize a fixed position stop control that is safe and has little change in notch and is comfortable to ride.

In the above embodiment, an example in which the various arithmetic units 10 to 15 are configured by hardware has been shown, but a microcomputer may be used for the arithmetic. An example of the program processing flow in this case is shown in FIG. This program has a function of obtaining the notch command N (t) based on the vehicle speed V _T , acceleration α _T , and the distance L ₁ to the stop target point.

Further, in the above-described embodiment, the membership function of the fuzzy base set for defining the fuzzy amount of the stop accuracy, which is the control purpose, is defined as in equations (5) and (6).
The present invention is not limited to this. For example, as shown in FIG. 7, the vehicle speed is a predetermined speed V _C (for example, 10 km
/ h) or more, l '(eg
It may be changed stepwise so that the point Q just before 2m) is targeted and the point O is targeted when the speed becomes V _C or less.

In the fuzzy reasoning in the above-described embodiment, the number of notches is increased or decreased by ± 1 notch, but it goes without saying that more notch changes may be added to the selection range by increasing the number of control rules.

〔The invention's effect〕

As described above, according to the present invention, after the vehicle has passed the predetermined position before the target stop point, the brake control start determination operation for determining whether or not the start time of the brake control operation is reached is periodically performed. After the brake control start time is reached, the determination operation of the brake control command according to the state of the vehicle is periodically performed, and if a preferable control result is obtained with the current brake control command, the control command is issued. Since the speed control of the vehicle is performed so as to keep the value as it is, the number of switching of the control command is reduced as compared with the conventional speed pattern following method, and the vehicle can be driven comfortably to the target position.

[Brief description of drawings]

FIG. 1 is a block diagram showing an example of a conventional fixed position vehicle stop control device, FIG. 2 is an operation explanatory diagram showing its speed pattern, FIG. 3 is a block diagram showing one embodiment of the present invention, FIG. FIG. 5 is a diagram for explaining the operation, FIG. 6 is a processing flowchart showing another embodiment of the present invention, and FIG. 7 is a diagram showing a speed pattern in still another embodiment of the present invention. . 1: Speed generator, 2 ': Speed acceleration calculation device, 3': Remaining distance calculation device, 4: Ground element, 5: Point detector, 9: Brake device,
10: Stop error calculation device, 11: Brake start designation device, 12Z,
12P, 12N: Ambiguous amount calculation device, 13: Notch change suppression device, 14: Control notch calculation device, 15: Brake command calculation device.

Claims (1)

[Claims] 1. A vehicle automatic control method for determining a control command according to the state of a vehicle, and performing speed control for stopping the vehicle at a target point according to the control command, wherein the vehicle has a predetermined position before the target stop point. After passing the position, the stop error of the vehicle with respect to the stop target point is periodically calculated based on the vehicle speed and the deceleration determined by the brake control command at that time, and the relationship between the stop error and the vehicle speed is calculated. From the above, it is judged whether the vehicle has reached the state where the brake control operation should be started, and after the vehicle reaches the brake control start state, the above-mentioned stop expected when the brake control command is kept as it is. The stop error with respect to the target point and the stop error predicted when the control command is changed by a predetermined amount are periodically calculated, and these stop errors are respectively determined by the predetermined control command and the memory. One of the above control rules is given to an ambiguous inference means that stores a plurality of control rules associated with the umbership function and is applied to the membership function according to the magnitude of the ambiguous amount of each stop error. A vehicle automatic control method comprising: selecting and controlling the speed of the vehicle by one control command specified by the control law.