JPH0392437A - Running control device for vehicle - Google Patents

Abstract

PURPOSE:To automatically adjust a risk in response to driving characteristics by providing a self-tuning means adjusting a risk index in response to variation as described later wherein said index is computed by a risk computing means when controlled variable computed by a proper vehicle speed actuated variable control means is changed by an accelerator pedal action or brake actuation action on the part of a driver. CONSTITUTION:When controlled variable is appropriately corrected to meet driver's own driving characteristics with an accelerator pedal or a brake actuated by a driver, deviation from the proper vehicle speed of his own car due to the aforesaid correction is detected by a self-tuning means 44 so that a risk computed by a risk computing means 34 is thereby adjusted in response to the aforesaid variation. Namely, when the speed of his own car becomes higher than a proper vehicle speed with the accelerator pedal actuated by the driver, the risk is adjusted to be small. And when the speed of his awn car becomes lower than the proper vehicle speed with the accelerator pedal actuated by the driver, the risk is adjusted to be large.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a vehicle travel control device, and particularly to a vehicle travel control device suitable for appropriately controlling the travel state of a vehicle to automatically follow a vehicle in front.

[Prior Art] Conventionally, a travel control device is well known in which a radar device is mounted on a vehicle to constantly monitor the inter-vehicle distance and relative speed to a vehicle in front, and to accelerate or decelerate the vehicle depending on the degree of danger.

As this type of travel control device, for example, Japanese Patent Application Laid-Open No. 60-9
A system disclosed in Japanese Patent No. 1500 is known.

FIG. 9 shows a schematic block diagram of this system. In the figure, a radar device 10 having an antenna ANT detects the inter-vehicle distance and relative speed to the vehicle ahead, and a speed sensor 12 determines the traveling speed of the own vehicle.

Then, the detected inter-vehicle distance, relative speed, and own vehicle speed are sent to the signal processing device 14. The signal processing device 14 calculates a risk index from these sent detection signals. In other words, when the vehicle in front decelerates and then comes to a stop, find the appropriate inter-vehicle distance necessary for your vehicle to stop without colliding with the vehicle in front, based on the driving conditions of the vehicle in front and the driving condition of your own vehicle. -Log (appropriate inter-vehicle distance/actual inter-vehicle distance) is used to calculate the risk index D.

This risk index calculated by the signal processing device 14 is sent to the display device 16 for audio-visual display, or the signal processing device 14 determines the acceleration/deceleration of the own vehicle from the risk index and issues commands to the actuator. By automatically controlling the brakes and accelerator, you can safely follow the vehicle in front of you.

However, in this system, the appropriate inter-vehicle distance or risk level is uniformly determined based on the relative driving conditions with the vehicle in front, so there is a problem that it cannot be adapted to the surrounding conditions and driving conditions that differ for each driver. there were.

Therefore, conventionally, a control device as disclosed in Japanese Patent Laid-Open No. 61-6031 has been considered. In this device, as shown in the block diagram of FIG. 10, a set inter-vehicle distance is calculated based on detection signals from a vehicle speed detecting means 18 that detects the own vehicle speed and an inter-vehicle distance detecting means 20 that detects the inter-vehicle distance to the preceding vehicle. The device 24 calculates a set inter-vehicle distance, that is, an appropriate inter-vehicle distance, and controls acceleration/deceleration based on this set inter-vehicle distance. When the driver wants to change the appropriate inter-vehicle distance depending on the driving condition, he or she can change the correction coefficient used when calculating the set distance by turning the manual knob of the inter-vehicle distance adjustment means 22 to increase or decrease the appropriate inter-vehicle distance. This is a short correction.

[Problems to be Solved by the Invention] However, in such a conventional device, a manual knob must be operated each time the appropriate inter-vehicle distance is desired to be changed, making the operation complicated. If the driver has to operate the manual knob each time to set the desired value, the advantage of automatic tracking, which is that the driver only needs to concentrate on steering operation while automatically following the vehicle in front, is lost. However, it is difficult for the driver to set this manual knob to a desired value while driving, and the driver's attention is focused on the operation at hand, which poses a problem in terms of safety.

The present invention was developed in view of the above-mentioned conventional problems, and its purpose is to automatically change the degree of danger and appropriate distance between vehicles according to the driving conditions that change for each driver, and to more safely and comfortably follow the vehicle in front. An object of the present invention is to provide a vehicle travel control device that can follow the vehicle.

[Means for Solving the Problems] In order to achieve the above object, the vehicle travel control device of the present invention includes a laser radar device that detects the inter-vehicle distance and relative speed to the vehicle in front, and a travel speed of the own vehicle. a vehicle speed sensor that calculates a vehicle speed; a risk calculation means that calculates a risk index based on detection signals from the laser radar device and the vehicle speed sensor; an appropriate vehicle speed operation amount control device that calculates an acceleration/deceleration control amount of the own vehicle based on the appropriate vehicle distance calculated by the appropriate vehicle distance calculation device; self-tuning means for adjusting the risk index calculated by the risk calculation means when the control amount calculated by the operation amount control means is changed by the driver's accelerator or brake operation; It is characterized by having the following.

[Effect]

The vehicle travel control device of the present invention has such a configuration,
Based on the detection signals from the laser radar device and the vehicle speed sensor, the degree of danger and appropriate vehicle speed are calculated to control the running of the own vehicle.

At this time, when the driver operates the accelerator or brake to appropriately correct the control amount to match his or her driving characteristics, the self-tuning means detects the deviation of the own vehicle speed from the appropriate vehicle speed due to this correction, and calculates the degree of risk. The degree of risk calculated by the means is adjusted according to this amount of displacement. In other words, when the driver operates the accelerator and the own vehicle speed becomes higher than the appropriate vehicle speed, the degree of danger is adjusted to be lower than before, and when the driver operates the brake and the own vehicle speed becomes lower than the own vehicle speed or the appropriate vehicle speed, the danger level is adjusted. Adjust the degree to be larger than before.

Then, the degree of risk is sequentially adjusted by the driver's accelerator or brake operations, so that the degree of risk is gradually evaluated in accordance with the driver's driving characteristics, and the appropriate vehicle speed is also adjusted according to this degree of risk. This allows for comfortable follow-up driving.

[Embodiments] Hereinafter, preferred embodiments of the vehicle travel control device according to the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of the configuration of this embodiment. In the figure, a laser radar device 30 mounted on the vehicle emits laser light at predetermined pulse intervals, and by receiving reflected laser light from the vehicle ahead, the inter-vehicle distance and relative speed to the vehicle ahead are detected. .

On the other hand, the traveling speed of the own vehicle is detected by a vehicle speed sensor 32. The inter-vehicle distance, relative speed, and own vehicle speed detected by the laser radar device 30 and the vehicle speed sensor 32 are sent to the risk level calculation means 34. Risk calculation means 34
performs fuzzy inference using each detection signal sent as a parameter, and calculates the degree of risk that matches the driver's sense as an index.

Hereinafter, the fuzzy inference performed by this risk calculation means 34 will be explained in detail using FIGS. 3 to 5.

FIG. 3 shows evaluation criteria for evaluating each parameter sent from the laser radar device 30 and the vehicle speed sensor 32. As shown in the figure, there are three evaluation criteria for vehicle speed and inter-vehicle distance: S (Smal 1: small), M (Mi
ddle: medium), B (Big: large), and relative speed is assigned N (Negative: negative), Z (Zero
: zero) and P (Positive) are assigned. Furthermore, there are four evaluation criteria for the degree of danger of the output to be calculated: VS (Very Small), S (Sm
a 1 1: Small), M (Middle: Medium),
B (Big) is assigned.

FIG. 4 shows the fuzzy control law expressed by the evaluation criteria assigned to each parameter in this way.

This fuzzy control law adopts rules that match the driver's senses. For example, the first row in the figure is ``If the own vehicle speed is B (large), the relative speed is N (negative), and the inter-vehicle distance is S ( If the vehicle speed is B (large), the relative speed is P (positive), and the inter-vehicle distance is S. (small), then the risk level is S (small).

Furthermore, Fig. 5 shows the membership function of the evaluation criteria assigned to each parameter, and Fig. 5 (A) shows the membership function of the own vehicle speed of S (low), M (medium), and B (high). Figure 5 (B) shows the membership functions of relative speeds N (negative), Z (zero), and P (positive), and Figure 5 (C) shows the membership functions of inter-vehicle distance S (small). M (medium), B
(large) membership function, and Fig. 5 (D
) is the risk level VS (very small), S (small), M
(medium) and B (large) membership functions, respectively. As is well known, a membership function indicates the degree to which a certain physical quantity applies to human senses. For example, in the membership function of the own vehicle speed in Figure 5 (A), when the own vehicle speed is 59 km/h, each The degree of evaluation standard is S (small), B (large), 10 M (medium) - 0.75, and the driver's sense of the vehicle speed of 50 km/h is 0.7.
A rating of 5 indicates that the speed is judged to be medium.

Now, the risk calculation means 34 inputs the values of each parameter sent from the laser radar device 30 and the vehicle speed sensor 32, and calculates the degree of the evaluation standard from these membership functions. For example, if the detected values are: own vehicle speed - 100 km/h, relative speed - 50 km/h, and inter-vehicle distance - 25 m, then from the membership function, own vehicle speed: S proverb M-0 B-1. 0 Relative speed: p-zo N-0. 5 Inter-vehicle distance: S-0. 2 M-0. The degree is 2 B-0.

Then, based on this degree, the degree of satisfaction with the fuzzy control law shown in FIG. 4, which is a basic rule, is evaluated. That is, in the above-mentioned example, for the rule in the third row of FIG. 2, and the satisfaction level of the condition part of this rule is 1. OX
0.5XO. 2 10. It becomes 1. The conclusion of this rule, the risk level, is S.
The membership function of is multiplied by the satisfaction level of this condition part to correct the membership function according to the satisfaction level.

Such operations are performed for all the fuzzy control laws in FIG. 4, the membership functions of the conclusion part are corrected according to the degree of satisfaction, and the OR of these corrected membership functions is calculated. Then, by calculating the center of gravity of this logical sum, it is possible to calculate the degree of risk that matches the driver's sense.

The risk calculated by the risk calculation means 34 is then sent to the appropriate inter-vehicle distance calculation means 36. The appropriate inter-vehicle distance calculating means 36 calculates an appropriate inter-vehicle distance between the preceding vehicle and the own vehicle using the sent risk index, the relative speed from the laser radar device 30, and the own vehicle speed from the vehicle speed sensor 22. That is, first, from the relative speed Vr and the own vehicle speed V, the reference inter-vehicle distance L that allows the vehicle to stop without colliding with the vehicle in front is calculated according to the following formula.
Find O.

Lo − V

Then, this standard inter-vehicle distance Lo is corrected by the risk index D calculated by the risk calculation means 34 to calculate the appropriate inter-vehicle distance L.

L-GIX (1+D)XLo However, the inter-vehicle distance gain is set to Gl.

The calculated appropriate inter-vehicle distance L is then sent to the appropriate vehicle speed operation amount control means 38. This appropriate vehicle speed operation amount control means 3
At step 8, based on the sent appropriate inter-vehicle distance, the amount of correction to be sent to the throttle actuator 40 and brake actuator 42 in order to maintain the appropriate vehicle speed is calculated by fuzzy reasoning, similar to the risk calculation means 34.

Similar to FIG. 3, FIG. 6 shows evaluation criteria for each parameter used in fuzzy inference.

The own vehicle speed and relative speed, which are sent to the appropriate vehicle speed operation amount control means 38 along with the appropriate inter-vehicle distance, are based on the same three evaluation standards S, M%B, and N%Z as shown in FIG. ．． P is assigned.

Furthermore, the inter-vehicle distance difference represents the difference between the appropriate inter-vehicle distance and the actual inter-vehicle distance, and for this parameter N (Ne
ga t ive: shorter than the appropriate inter-vehicle distance), Z(
Zero: Appropriate following distance M), P (Pos it
ive: longer than the appropriate inter-vehicle distance), and five evaluation criteria NS (Neg
at ivesmal1: Small deceleration), NB (N
2 (maintain current vehicle speed), PS (PositiveSmall: small acceleration), and PB (Positive Big: large acceleration).

FIG. 7 shows the fuzzy control law expressed by the evaluation criteria assigned to each parameter in this way.

Similar to Figure 4, this fuzzy control law also adopts rules that match the driver's senses.For example, the first row in the figure states, ``If the own vehicle speed is B (large) and the inter-vehicle distance difference is N (appropriate). The third row in the figure shows the rule that ``If own vehicle speed is B (larger) and the relative speed is N (negative), then the operation correction amount is NB (greater deceleration).'' If the difference is P (longer than the appropriate inter-vehicle distance) and the relative speed is 2 (zero), then the operation correction amount is 2 (maintain the current vehicle speed).

Figure 8 shows the membership functions of each evaluation criterion used to evaluate the degree of satisfaction of these rules, and Figure 8 (A) shows the membership functions of S, M, and B of own vehicle speed. Figure 8 (B) shows the membership function of relative speed N, Z, B, and Figure 8 (C) shows the membership function of inter-vehicle distance difference N%Z.
, P, and FIG. 8(D) shows the membership functions of the operation correction amounts NB, NS%Z, PS, and PB, respectively.

When calculating the operation correction amount, first the degree of each parameter is determined. For example, if the inter-vehicle distance difference is -50 m1, that is, 50 m shorter than the appropriate inter-vehicle distance, the own vehicle speed -100
Km/h, considering that the relative speed is 1150 m,
From the membership function, own vehicle speed: S cod O M-0. 2 B-1. 0 Inter-vehicle distance difference: P-Z-O NO 1.0 Relative speed: N-Z-0.5 P 0. Then, for the first stage rule in the fuzzy control law of FIG. 7, the degree of own vehicle speed B -1.0 and the degree N of inter-vehicle distance difference -1. 0 Degree of relative velocity N -0. 5, and the satisfaction level of the condition part of this rule is 1. OXI.
OX0.5 -0.5. Then, the membership function whose operation correction amount is NB (large deceleration), which is the conclusion part of this rule, is multiplied by the satisfaction level of this condition part to correct the membership function according to the satisfaction level.

Such operations are performed for all the fuzzy control laws shown in FIG. 7, the membership functions of the conclusion part are corrected according to the degree of satisfaction of the condition part, and the OR of these corrected membership functions is calculated. Then, by calculating the center of gravity of this logical sum, it is possible to calculate an operation correction amount that matches the driver's sense and instruct the throttle actuator 40 and brake actuator 42.

In this way, in this embodiment, it is possible to perform control that matches the driving sensation of the driver using fuzzy inference, but the control obtained in this way may not be optimal depending on the driver. In other words, drivers generally perceive different degrees of danger even with the same inter-vehicle distance and vehicle speed, and as a result, some drivers may brake automatically even when they do not judge it to be dangerous, or some drivers may The calculated appropriate vehicle speed does not necessarily match the different driving sensations of each driver, such as the fact that braking is slow even when the driver wants to maintain a little more distance between vehicles. Therefore, in this embodiment, a self-tuning means 4 that can automatically match the characteristics of each driver is provided.
There are 4.

FIG. 2 is a flowchart explaining the function of this self-tuning means 44. This self-tuning means 44 receives the operation correction amount information from the appropriate vehicle speed operation amount control means 38 and the own vehicle speed from the vehicle speed sensor 32, and compares the appropriate vehicle speed with the actual own vehicle speed (hereinafter referred to as actual vehicle speed). Step 52). That is, if the driver operates the accelerator or brake to change the appropriate vehicle speed during travel control, the actual vehicle speed and the appropriate vehicle speed will be different values. Therefore,
If the determination in step 52 is No, it means that the driver operated the accelerator or brake.

If the determination is No, then in step 54, the magnitude relationship between the appropriate vehicle speed and the actual vehicle speed is compared.

Actual vehicle speed> When the vehicle speed is appropriate, it indicates that the driver has operated the accelerator, and this indicates that the driver has operated the accelerator.
This means that the appropriate vehicle speed calculated by the series of travel control devices in step 8 was not appropriate for the driver and was relatively low. Therefore, when the determination in step 54 is YES, the self-tuning means 44 sends a signal to the risk calculation means 34 to change the degree of each evaluation standard of the risk parameter of the membership function shown in FIG. The risk level is evaluated to be lower (step 58).

Also, when the actual vehicle is fast and at a proper vehicle speed, it indicates that the driver operated the brake, and this indicates that the driver
4. This means that the appropriate vehicle speed calculated by the series of travel control devices including the appropriate inter-vehicle distance calculation means 36 and the appropriate vehicle speed operation amount control means 38 was not appropriate for the driver and was relatively high. Therefore, when the determination in step 54 is No, the self-tuning means 44 sends a signal to the risk calculation means 34 to change the degree of each evaluation criterion of the risk parameter of the membership function shown in FIG. The degree of risk is evaluated to be high (step 56).

In this way, whether or not the driver has made corrections to the appropriate vehicle speed can be determined based on the magnitude relationship between the appropriate vehicle speed and the actual vehicle speed, and when the driver operates the accelerator, the driver operates the brakes to reduce the risk. When this happens, the self-tuning means 44 adjusts the evaluation criteria for the risk calculation parameters so as to increase the risk, so that the risk calculated by the risk calculation means 34 sequentially matches the driver's sense of driving. Since the value is adjusted accordingly, the number of times the driver has to operate the accelerator or brake gradually decreases, allowing comfortable automatic follow-up driving.

[Effects of the Invention] As explained above, according to the present invention, the degree of risk and the appropriate inter-vehicle distance can be automatically changed in accordance with the driving characteristics of the driver, and therefore the driver can adjust the steering operation, etc. This allows you to concentrate on other activities, and allows you to follow the vehicle in front more safely and comfortably.

[Brief explanation of drawings]

Fig. 1 is a block diagram of an embodiment of the vehicle travel control device according to the present invention, Fig. 2 is a flowchart of the embodiment, and Fig. 3 is a table showing risk control parameter evaluation criteria of the embodiment. , Fig. 4 is a table showing the risk level fuzzy control law of the same example, Fig. 5 is a graph showing the membership function of the same example, and Fig. 6 is the operation correction amount control parameter evaluation standard of the same example. , FIG. 7 is a table showing the operation correction amount fuzzy control law of the same embodiment, FIG. 8 is a graph showing the membership function of the same embodiment, and FIGS. 9 and 10 are the conventional FIG. 1 is a block diagram of a system or device. 30 ... Laser radar device 32 ... Vehicle speed sensor risk level calculation means Appropriate inter-vehicle distance calculation means Appropriate vehicle speed operation amount control means Throttle actuator Brake actuator Self-tuning means

Claims (1)

[Scope of Claims] A laser radar device that detects the inter-vehicle distance and relative speed to the vehicle in front, a vehicle speed sensor that detects the traveling speed of the own vehicle, and a risk level based on the detection signals from the laser radar device and the vehicle speed sensor. a risk calculation means for calculating an index; an appropriate inter-vehicle distance calculation means for calculating an appropriate inter-vehicle distance between the vehicle in front and the host vehicle based on the risk index calculated by the risk-degree calculation means; and an appropriate inter-vehicle distance calculation means an appropriate vehicle speed operation amount control means that calculates an acceleration/deceleration control amount of the host vehicle based on the appropriate inter-vehicle distance calculated by the vehicle; and the control amount calculated by the appropriate vehicle speed operation amount control means is changed by the driver's accelerator or brake operation. self-tuning means for adjusting the risk index calculated by the risk calculation means when the change occurs according to the amount of change; A vehicle travel control device that adjusts and controls the travel of a vehicle.