JP2700495B2 - Travel control device for vehicles - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicular travel control device, and more particularly to a vehicular travel control device suitable for automatically controlling the traveling state of an own vehicle and automatically following a preceding vehicle.

2. Description of the Related Art Conventionally, a traveling control device is known in which a radar device is mounted on an automobile to constantly monitor an inter-vehicle distance and a relative speed with a preceding vehicle, and to accelerate or decelerate the own vehicle in accordance with a degree of danger.

For example, Japanese Patent Application Laid-Open No. 60-91 discloses this type of travel control device.
A system disclosed in Japanese Patent Publication No. 500 is known. Ninth
The figure shows a schematic block diagram of this system. In the figure, the inter-vehicle distance and the relative speed with respect to a preceding vehicle are detected by a radar device 10 having an antenna ANT, and the traveling speed of the own vehicle is obtained by a speed sensor 12.

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. That is, an appropriate inter-vehicle distance necessary for the own vehicle to be able to stop without collision when the preceding vehicle decelerates to a stop state is determined from the running state of the preceding vehicle and the running state of the own vehicle. = Log (appropriate inter-vehicle distance / actual inter-vehicle distance) The risk index D is calculated according to the following formula.

The risk index calculated by the signal processing device 14 is sent to the display device 16 and displayed audio-visually, or the signal processing device 14 determines acceleration / deceleration of the vehicle based on the risk index and issues a command to the actuator. As a result, the brake and the accelerator are automatically controlled, and the vehicle can follow the vehicle ahead ahead safely.

However, in this system, the appropriate inter-vehicle distance or the degree of danger is determined uniformly by the relative running condition with respect to the preceding vehicle. there were.

Therefore, a control device as disclosed in Japanese Patent Application Laid-Open No. 61-6031 has been conventionally considered. In this apparatus, 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 for detecting the own vehicle speed and an inter-vehicle distance detecting means 20 for detecting an inter-vehicle distance to a preceding vehicle. In this configuration, a set inter-vehicle distance, that is, an appropriate inter-vehicle distance is calculated by the means 24, and acceleration / deceleration is controlled based on the set inter-vehicle distance. When the driver wants to change the appropriate inter-vehicle distance according to the traveling state, the inter-vehicle distance adjusting means 22
By turning the manual knob, the correction coefficient used for calculating the set distance is changed, and the appropriate inter-vehicle distance is corrected to be longer or shorter.

[Problems to be Solved by the Invention] However, in such a conventional device, a manual knob must be operated each time the proper inter-vehicle distance is to be changed, and the operation becomes complicated. In this way, the manual knob must be operated each time to set the desired value, so that the advantage of the automatic following that the driver only needs to concentrate on the steering operation during the automatic following of the preceding vehicle is lost. Rather, it is difficult for the driver to set the manual knob to a desired value during driving, and the driver's attention is paid to the operation at hand, which poses a problem of giving consideration to safety.

The present invention has been made in view of the above conventional problems,
It is an object of the present invention to provide a traveling control device for a vehicle that can automatically change a degree of danger or an appropriate inter-vehicle distance according to a traveling state that changes for each driver, and can follow a preceding vehicle more safely and comfortably. It is in.

[Means for Solving the Problems] To achieve the above object, a vehicle travel control device according to claim 1 is a vehicle travel control device that controls the travel of a vehicle according to the driving characteristics of a driver. Environment recognition means for recognizing the driving environment of the vehicle, situation recognition means for recognizing the driving situation of the vehicle, and the degree of risk as an evaluation criterion of the driving characteristic unique to the driver, using the recognized driving environment and the driving situation as variables. Calculating means for calculating an index, and control means for optimizing the running condition according to the calculated risk index,
When the optimized driving situation is changed by the driver's driving operation, the change is regarded as inappropriate in the evaluation of the driving characteristics, and the risk index is changed according to the situation change in order to eliminate the inappropriateness. Adjusting means for adjusting.

In order to achieve the above object, a vehicle traveling control device according to claim 2 is the vehicle traveling control device according to claim 1, wherein the arithmetic unit is configured to preliminarily determine the driver based on the traveling environment and the traveling state. The risk index is calculated by performing fuzzy inference using a membership function determined according to driving characteristics.

In order to achieve the above object, a vehicle running control device according to claim 3 is the vehicle running control device according to claim 2, wherein the adjustment unit changes the membership function according to the status change. And adjusting the risk index.

In order to achieve the above object, a vehicle traveling control device according to claim 4 includes a radar device that detects an inter-vehicle distance and a relative speed with a preceding vehicle, a vehicle speed sensor that detects a traveling speed of the own vehicle, A risk calculating unit that calculates a risk index, which is an evaluation criterion of a driving characteristic of a driver, based on detection signals from the radar device and a vehicle speed sensor, using the inter-vehicle distance, the relative speed, and the traveling speed of the own vehicle as variables, An appropriate inter-vehicle distance calculating means for calculating an appropriate inter-vehicle distance between the preceding vehicle and the own vehicle based on the risk index calculated by the danger degree calculating means; and an appropriate inter-vehicle distance calculated by the appropriate inter-vehicle distance calculated by the appropriate inter-vehicle distance calculating means. An appropriate vehicle speed operation amount control means for calculating an acceleration / deceleration control amount of the vehicle; and a control amount calculated by the appropriate vehicle speed operation amount control means when the control amount is changed by an accelerator or brake operation of a driver. Self-tuning means for adjusting the risk index calculated by the risk calculation means in accordance with the change amount in order to eliminate the inappropriate evaluation of the characteristics, and The invention is characterized in that the risk index is adjusted according to the accelerator or brake operation status to control the traveling of the vehicle.

Further, in order to achieve the above object, a vehicle travel control device according to claim 5 is a vehicle travel control device according to claim 4, wherein the self-tuning means is provided when a driver performs a brake operation. Adjusts the risk index to an increasing side, and adjusts the risk index to a decreasing side when a driver performs an accelerator operation.

[Operation] In the vehicle traveling control device according to the first, second, and third aspects, the traveling environment detects the inter-vehicle distance and the relative speed between the preceding vehicle and the own vehicle, and detects the speed of the own vehicle as the traveling condition. Is done. The computing means computes a risk index by performing fuzzy inference from these traveling environments and traveling conditions using a membership function predetermined according to the driving characteristics of the driver. Further, when the driving situation optimized according to the risk index calculated in this way is changed by the driving operation of the driver, the risk is changed by changing the membership function according to the result of the change. The degree index is adjusted to match the driving characteristics of the driver.

Therefore, the risk index is gradually adjusted by the driving operation of the driver, for example, the accelerator or the brake operation, so that the risk evaluation matching the driving characteristics of the driver is gradually performed.

Further, in the vehicle traveling control device according to the fourth and fifth aspects, the risk and the appropriate vehicle speed are calculated based on the detection signals from the laser radar device and the vehicle speed sensor, and the traveling of the own vehicle is controlled.

At this time, when the driver operates the accelerator or the brake to appropriately adjust the control amount to match his own driving characteristics, the self-tuning means detects the displacement of the own vehicle speed from the appropriate vehicle speed due to this correction, and calculates the degree of risk. The risk calculated by the means is adjusted according to the amount of displacement. That is, 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 smaller than before,
When the driver operates the brake and the own vehicle speed becomes lower than the appropriate vehicle speed, the risk is adjusted to be larger than before.

Then, the risk is adjusted sequentially by the driver's accelerator or brake operation, so that the risk evaluation gradually matching the driver's driving characteristics is performed,
Since the appropriate vehicle speed is also adjusted according to the degree of danger, comfortable following running is possible.

[Embodiment] Hereinafter, a preferred embodiment of a vehicle traveling control device according to the present invention will be described with reference to the drawings. FIG. 1 is a configuration block diagram of the present embodiment. In the figure, a laser radar device 30 mounted on the own vehicle irradiates laser light at a predetermined pulse interval and receives a reflected laser light from a preceding vehicle to detect an inter-vehicle distance to a preceding vehicle and a relative speed. .

On the other hand, the traveling speed of the own vehicle is detected by the vehicle speed sensor 32. Then, the laser radar device 30, the vehicle speed sensor 32
The inter-vehicle distance, the relative speed, and the own vehicle speed detected by the above are sent to the risk degree calculating means 34. The risk calculating means 34 performs fuzzy inference using the transmitted detection signals as parameters, and calculates a risk corresponding to the driver's feeling by an index.
Hereinafter, the fuzzy inference performed by the risk calculating means 34 will be described in detail with reference to FIGS.

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, three evaluation criteria S (Small: small), M (Middle: middle), B
(Big: big) and N (Negative:
Negative), Z (Zero: zero), and P (Positive: positive) are assigned. Furthermore, four evaluation criteria VS (VerySmall: extremely small), S (Small: small), M (Middle: middle), and B (Big: large) are assigned to the risk of output to be calculated.

FIG. 4 shows a fuzzy control law expressed by the evaluation criteria assigned to each parameter. This fuzzy control law adopts a rule that matches the driver's feeling. For example, the first row in the figure shows “If the vehicle speed is B (large), the delivery 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, the third row in the figure indicates that the risk is B (large) if the vehicle speed is low. (Small), the risk is S (small)].

FIG. 5 shows a membership function of an evaluation criterion assigned to each parameter, and FIG. 5 (A)
Is a membership function of S (small), M (medium) and B (large) of the vehicle speed, and FIG.
FIG. 5 (C) shows the membership functions of S (small), M (medium) and B (large) of the following distance. FIG. 5D shows the membership functions of VS (extremely small), S (small), M (medium), and B (large) of the degree of danger, respectively. As is well known, the 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 shown in FIG. 5 (A), when the own vehicle speed is 50 km / h, The evaluation criteria are as follows: S (small) = B (large) = 0 M (medium) = 0.75, and a vehicle speed of 50 km / h is judged to be a medium speed at the driver's sense of 0.75. Is shown.

The risk calculating means 34 inputs the values of the parameters sent from the laser radar device 30 and the vehicle speed sensor 32, and obtains the evaluation criteria from the membership functions. For example, when the detected value is as follows: own vehicle speed = 100 km / h relative speed = −50 km / h inter-vehicle distance = 25 m From the membership function, own vehicle speed: S = M = 0 B = 1.0 Relative speed: P = Z = 0 N = 0.5 Inter-vehicle distance: S = 0.2 M = 0.2 B = 0

Then, the degree of satisfaction of the fuzzy control rule shown in FIG. 4, which is the basic rule, is evaluated based on this degree. That is, in the above example, the own vehicle speed is the degree of B = 1.0, the relative speed is the degree of P = 0, and the inter-vehicle distance is the degree of S = 0.2 with respect to the rule in the third row of FIG. The satisfaction of the condition part is 1.0 × 0 × 0.2 = 0. Then, the danger that is the conclusion part of this rule is S
Is multiplied by the satisfaction degree of the condition part to correct the membership function according to the satisfaction degree.

Such an operation is performed for all the fuzzy control rules in FIG. 4 to correct the membership function of the conclusion part according to the degree of satisfaction, and the logical sum of these corrected membership functions is obtained. Then, by calculating the center of gravity of the logical sum, it is possible to calculate the degree of risk that matches the driver's feeling.

The risk calculated by the risk calculating means 34 is sent to the appropriate inter-vehicle distance calculating means 36 next. Appropriate inter-vehicle distance calculation 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, the reference inter-vehicle distance Lo at which the vehicle can stop without colliding with the preceding vehicle is obtained from the relative speed Vr and the own vehicle speed V according to the following equation.

Lo = V × τ + (Vs ² −V ² ) / 2α Vs = V + Vr Here, τ represents the idle running time of the vehicle and α represents the deceleration.

Then, the reference inter-vehicle distance Lo is corrected by the risk index D calculated by the risk calculating means 34, and the corrected inter-vehicle distance L is calculated.

L = G1 × (1 + D) × Lo where the inter-vehicle distance gain is G1. The inter-vehicle distance gain G1 is, for example, a predetermined constant.

Then, the calculated appropriate inter-vehicle distance L is sent to the appropriate vehicle speed operation amount control means 38. This appropriate vehicle speed manipulated variable control means 38
Then, based on the transmitted appropriate inter-vehicle distance, a risk amount calculating means calculates a correction amount to be sent to the throttle actuator 40 and the brake actuator 42 in order to obtain an appropriate vehicle speed.
Calculated by fuzzy inference as in 34.

FIG. 6 shows the evaluation criteria for each parameter used in fuzzy inference, as in FIG. The own vehicle speed and the relative speed sent to the appropriate vehicle speed operation amount control means 38 together with the appropriate inter-vehicle distance include three evaluation criteria S similar to those in FIG.
M, B and N, Z, P are assigned. The inter-vehicle distance difference represents the difference between the appropriate inter-vehicle distance and the actual inter-vehicle distance. For this parameter, N (Negative: shorter than the appropriate inter-vehicle distance), Z (Zero: appropriate inter-vehicle distance), P ( Posit
ive: longer than the appropriate inter-vehicle distance), and five evaluation criteria NS (NegativeSmall: decelerate slightly), NB (NegativeBig: greatly decelerate), Z (maintain current vehicle speed), PS ( PositiveSmall: small acceleration, PB (Posi
tiveBig: greatly accelerated).

FIG. 7 shows a fuzzy control law expressed by the evaluation criteria assigned to each parameter. This fuzzy control law also employs a rule that matches the driver's sense, as in FIG. 4. For example, the first tier in the figure shows "If the vehicle speed is B (large) and the inter-vehicle distance difference is N (appropriate). If the relative speed is shorter than the inter-vehicle distance) and the relative speed is N (negative), the operation correction amount is NB (large deceleration). If the difference is P (longer than the appropriate inter-vehicle distance) and the relative speed is Z (zero), the operation correction amount is Z (maintains the current vehicle speed). "

FIG. 8 shows the membership function of each evaluation criterion used to evaluate the satisfaction of these rules, and FIG. 8 (A) shows the membership function of S, M, B of the own vehicle speed. FIG. 8 (B) shows the membership function of N, Z, and B of the relative speed, and FIG. 8 (C) shows N, Z of the difference between the vehicles.
FIG. 8 (D) shows membership functions of NB, NS, Z, PS, and PB of the operation correction amount, respectively.

When calculating the operation correction amount, first, the degree of each parameter is obtained. For example, when the inter-vehicle distance difference is −50 m, that is, 50 m shorter than the corrected inter-vehicle distance, the own vehicle speed = 100 Km / h,
Considering that the relative speed is -50 m, the own vehicle speed: S = 0 M = 0.2 B = 1.0 Inter-vehicle distance difference: P = Z = 0 N = 1.0 Relative speed: N = Z = 0.5 P = 0. Then, with respect to the first rule in the fuzzy control law of FIG. 7, the own vehicle speed becomes B degree = 1.0 The inter-vehicle distance difference becomes N degree = 1.0 The relative speed becomes N degree = 0.5 The satisfaction level of the condition part is 1.0 × 1.0 × 0.5 = 0.5. Then, the membership function whose operation correction amount is NB (largely decelerated), which is the conclusion part of this rule, is multiplied by the satisfaction degree of this condition part to correct the membership function according to the satisfaction degree.

Such an operation is performed for all the fuzzy control rules shown in FIG. 7 to correct the membership function of the conclusion part according to the degree of satisfaction of the condition part, and the logical sum of these corrected membership functions is obtained. Then, by calculating the center of gravity of the logical sum, an operation correction amount that matches the driver's feeling can be calculated and commanded to the throttle actuator 40 and the brake actuator 42.

As described above, in the present embodiment, control that matches the driving feeling of the driving vehicle can be performed using fuzzy inference. However, depending on the driver, the obtained control may not be optimal. That is, in general, the same inter-vehicle distance depends on the driver,
Depending on the driver's own speed, the perceived danger is different.Therefore, depending on the driver, braking is automatically performed even in situations where it is not judged to be dangerous, or even if some drivers want to take a little more distance The calculated appropriate vehicle speed does not always match the driving sensation that is different for each driver, such as when playing is difficult. Therefore, in this embodiment, a self-tuning means that can automatically match the characteristics of each driver
44 are provided.

FIG. 2 is a flowchart for explaining the function of the self-tuning means 44. The 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). In other words, if the driver changes the appropriate vehicle speed by operating the accelerator or brake during traveling control,
The actual vehicle speed and the appropriate vehicle speed have different values. Therefore, if NO is determined in this step 52, it means that the driver has operated the accelerator or the 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. When the actual vehicle speed is greater than the appropriate vehicle speed, it indicates that the driver has operated the accelerator, which indicates that the driver has calculated the danger degree calculating means 34 and the appropriate inter-vehicle distance calculating means.
The proper vehicle speed calculated by a series of travel control devices of 36 and the appropriate vehicle speed operation amount control means 38 is not appropriate for oneself,
This means that the speed was relatively low. Therefore, when the determination at step 54 is YES, the self-tuning means 44 sends a signal to the risk calculating means 34 to change the degree of each evaluation criterion of the risk parameter of the membership function shown in FIG. The risk is evaluated to be smaller (step 58).

Further, when the actual vehicle speed is smaller than the appropriate vehicle speed, it indicates that the driver has operated the brake, which indicates that the driver
34, which means that the appropriate vehicle speed calculated by a series of travel control devices of the appropriate inter-vehicle distance calculation means 36 and the appropriate vehicle speed operation amount control means 38 was not appropriate for the user and was relatively high. Therefore, when the determination at step 54 is NO, the self-tuning means 44
A signal is sent to 34 and the degree of each evaluation criterion of the risk parameter of the membership function shown in FIG. 5 is changed to evaluate the risk to be higher (step 56).

In this way, it is determined whether or not the driver has corrected the appropriate vehicle speed based on the magnitude relationship between the appropriate vehicle speed and the actual vehicle speed, and when the driver operates the accelerator, the degree of danger is reduced.
On the other hand, when the brake is operated, the self-tuning means 44 adjusts the evaluation criterion of the risk calculation parameter so as to increase the risk, whereby the risk calculated by the risk calculation means 34 is sequentially changed by the driver. Since the value is adjusted to a value that matches the sense, the number of times the driver performs the accelerator or the brake operation is sequentially reduced, and comfortable automatic following running is possible.

[Effects of the Invention] As described above, according to the present invention, it is possible to automatically change the degree of danger and the appropriate inter-vehicle distance in accordance with the driving characteristics of the driver. The user can concentrate on other operations and can follow the preceding vehicle more safely and comfortably.

[Brief description of the drawings]

FIG. 1 is a block diagram of an embodiment of a 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 fuzzy control law of the embodiment, FIG. 5 is a graph showing the membership function of the embodiment, and FIG. 6 is an operation correction amount control parameter evaluation criterion of the embodiment. FIG. 7 is a table showing the operation correction amount fuzzy control law of the embodiment, FIG. 8 is a graph showing the membership function of the embodiment, FIG. 9 and FIG. It is a block diagram of a system or an apparatus. 30 Laser radar device 32 Vehicle speed sensor 34 Danger calculation means 36 Appropriate inter-vehicle distance calculation means 38 Appropriate vehicle speed operation amount control means 40 Throttle actuator 42 Brake actuator 44 Self-tuning means

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical indication G05D 1/02 G05D 1/02 J (72) Inventor Hironori Miyakoshi 1 Toyota Town, Toyota City, Aichi Prefecture Toyota (56) References JP-A-61-6031 (JP, A) JP-A-63-24654 (JP, A) JP-A-62-23805 (JP, A) JP, U) US Patent 4,829,434 (US, A)

Claims (5)

(57) [Claims] 1. A traveling control device for a vehicle which controls traveling of a vehicle according to driving characteristics of a driver, comprising: environment recognition means for recognizing a traveling environment of the vehicle; Calculating means for calculating a risk index, which is an evaluation criterion of a driver-specific driving characteristic, using the recognized driving environment and the driving condition as variables, and optimizing the driving condition according to the calculated risk index. When the optimized driving condition is changed by a driving operation of a driver, the change is regarded as an inappropriate evaluation of the driving characteristics, and the control is performed in accordance with the status change to eliminate the inappropriateness. And a control means for adjusting the risk index by means of a vehicle. 2. The driving control device for a vehicle according to claim 1, wherein the calculating means performs fuzzy inference from the driving environment and the driving condition by a membership function predetermined according to a driving characteristic of a driver. A vehicle travel control device for calculating a degree index. 3. A vehicle travel control system according to claim 2, wherein said adjusting means changes said membership function and adjusts said risk index according to said situation change. apparatus. 4. A radar device for detecting an inter-vehicle distance and a relative speed with a preceding vehicle; a vehicle speed sensor for detecting a traveling speed of the own vehicle; and a inter-vehicle distance based on detection signals from the radar device and the vehicle speed sensor. A risk calculating means for calculating a risk index, which is an evaluation criterion for the driving characteristics of the driver, using the relative speed and the traveling speed of the own vehicle as variables, and a vehicle ahead based on the risk index calculated by the risk calculating means. An appropriate inter-vehicle distance calculation means for calculating an appropriate inter-vehicle distance with the own vehicle; an appropriate vehicle speed operation amount control means for calculating an acceleration / deceleration control amount of the own vehicle based on the appropriate inter-vehicle distance calculated by the appropriate inter-vehicle distance calculation means; When the control amount calculated by the appropriate vehicle speed operation amount control means is changed by the driver's accelerator or brake operation, it is considered that the evaluation of the driving characteristics is inappropriate, and in order to eliminate this inappropriateness. Self-tuning means for adjusting the risk index calculated by the risk calculating means in accordance with the amount of change, and adjusting the risk index in accordance with the driver's accelerator or brake operation status. A vehicle travel control device for controlling travel of a vehicle. 5. The travel control device for a vehicle according to claim 4, wherein the self-tuning means adjusts the risk index to an increasing side when the driver performs a brake operation, and the driver performs an accelerator operation. A vehicle travel control device that adjusts the risk index to a decreasing side when the control is performed.