JPH1120496A - Automatic cruise controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an automatic cruise controller that can hold excellent driving feeling regardless of the state of a travel road. SOLUTION: The target value AT is obtained on the basis of intervehicle time deviation ΔT and relative speed Vr, and the target value AT is corrected using correction factors K0, K3 set according to the gradient and bending degree of a travel road. An output adjustment command VLc inputted to an engine output control part 20, and an auxiliary brake operation command BC inputted to a brake control part 18 are generated on the basis of the corrected target value ATh. In case of the target value AT being the positive value (that is, target acceleration) when travel resistance estimated from engine speed and fuel injection quantity is small (during travel on a downward slope, for instance), the correction factor K0 is set to the smaller value than 1.0 so as to decrease target acceleration. In case of the target value At being the negative value (that is, target deceleration), the correction factor is set to the larger value than 1.0 so as to increase target deceleration.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an auto cruise control device capable of inter-vehicle cruise for driving a vehicle so as to follow a preceding vehicle while maintaining a target inter-vehicle distance.

[0002]

2. Description of the Related Art Conventionally, in this type of apparatus, a target inter-vehicle distance is determined on the basis of the traveling state of the own vehicle and the preceding vehicle (speed, acceleration of the own vehicle, relative distance and speed of the preceding vehicle, etc.). A target acceleration or a target deceleration (hereinafter, collectively referred to as a target value) for maintaining and causing the vehicle to follow the preceding vehicle is determined,
The actual acceleration matches the target value by controlling the engine output by controlling the fuel injection amount according to this target value, or adjusting the braking force by activating auxiliary brakes such as exhaust brakes and retarding devices. In this way, the driving force transmitted from the engine to the wheels is adjusted.

[0003]

However, in such a device, when a certain driving force is given to the own vehicle, the response when actually accelerating or decelerating according to the driving force is low.
Because the road is different from a flat road and a sloping road, the driving feeling changes irrespective of the driver's intention according to the state of the running road, and the driver may feel uncomfortable. there were.

That is, for example, in the case of a slope, even if the same driving force is applied, the running resistance is small on a downhill, so that it is easy to accelerate and it is difficult to decelerate. Because it is difficult to accelerate and decelerate easily because it is large, acceleration or deceleration that the driver thinks is not performed or conversely, acceleration or deceleration is performed more rapidly than expected, making the driver irritated or They can give you anxiety.

[0005] In addition, when the traveling path is curved, the driver generally does not want to accelerate, but the acceleration / deceleration is determined according to the behavior of the preceding vehicle. In some cases, the vehicle may exhibit a behavior contrary to the driver's intention, for example, causing the driver to feel uneasy.

The present invention has been made to solve the above problems.
It is an object of the present invention to provide an automatic cruise control device capable of maintaining a good driving feeling irrespective of the state of a traveling road.

[0007]

According to the first aspect of the present invention, there is provided an auto cruise control device for detecting the behavior of a vehicle including at least a speed and an acceleration. Based on the detection result of the information detecting means and the preceding vehicle information detecting means for detecting the relative position and speed of the preceding vehicle with respect to the own vehicle, the target value calculating means maintains the target inter-vehicle distance and sets the preceding vehicle to the preceding vehicle. The driving force control means controls the driving force adjusting means so that the actual acceleration detected by the vehicle information detecting means coincides with the target acceleration. As a result, the driving force transmitted from the engine to the wheels is adjusted by the driving force adjusting means without depending on the operation of the driver, and the own vehicle follows the preceding vehicle and travels.

At this time, the traveling road state estimating means estimates the state of the traveling road on which the own vehicle is traveling on the basis of the detection result of the own vehicle information detecting means, and corrects the target acceleration based on the estimation result. Means for increasing or decreasing the target acceleration obtained by the target value calculating means. It should be noted that the response of acceleration is improved as the target acceleration is increased, and the response of deceleration is improved as the target deceleration is increased.

Therefore, according to the automatic cruise control device of the present invention, when the state of the traveling road where the acceleration / deceleration response to the driving force changes is detected, the acceleration / deceleration response is kept constant. If the target value is corrected so as to reduce the target acceleration or the target deceleration when the driver detects a state of the traveling road where acceleration or deceleration is not desired, the driving Regardless of the road condition, acceleration and deceleration will always be performed according to the driver's intention,
Good driving feeling can be secured.

Next, in the automatic cruise control device according to the second aspect, the own vehicle information detecting means detects the engine speed and the fuel injection amount as the behavior of the own vehicle, and further, the traveling road state estimating means includes: The running resistance estimating means for estimating that the running resistance of the vehicle based on the gradient of the running road is small as the engine load obtained from the relationship between the engine speed and the fuel injection amount is small and the actual acceleration is large,
The target value correcting means includes a gradient correcting means for decreasing the target acceleration or increasing the target deceleration as the traveling resistance estimated by the traveling resistance estimating means is smaller.

That is, if the vehicle decelerates despite the fact that the engine load is equal to or greater than the vehicle speed, it can be estimated that the vehicle is traveling on an uphill with a large running resistance. If the vehicle accelerates in spite of the fact that the vehicle is accelerating or smaller, it can be estimated that the vehicle is traveling on a downhill with a small running resistance.

According to the auto cruise control device of the present invention, the correction is made to increase the target deceleration on a downhill with a small running resistance where the response of deceleration decreases, and conversely, the response of acceleration decreases. On an uphill with large running resistance,
Since the correction is made so as to increase the target acceleration, a constant acceleration / deceleration feeling is always obtained regardless of the slope of the slope, and a good driving feeling can be maintained.

Next, in the auto cruise control device according to the third aspect, the own vehicle information detecting means detects a steering angle of the steering as a behavior of the own vehicle, and further, the traveling road state estimating means detects the steering angle. Along with a curve estimating means for estimating the degree of turning of the traveling path based on the target value correcting means,
A curve correcting means is provided which reduces the target acceleration calculated by the target value calculating means as the degree of curve of the traveling path estimated by the curve estimating means increases.

That is, according to the auto cruise control device of the present invention, the response of acceleration is generally reduced on a curved traveling road on which the driver does not want to accelerate, so that the vehicle is not greatly accelerated. Therefore, it is possible to drive according to the driver's intention, and as a result, it is possible to improve the driving safety without giving the driver an uneasy feeling.

Next, in the automatic cruise control device according to the fourth aspect, the driving force adjusting means includes an auxiliary brake for adjusting the braking force, and the driving force control means includes a deviation between the target deceleration and the actual acceleration. Is greater than a preset activation threshold, the auxiliary brake is activated.

That is, when the target value correcting means corrects the target deceleration to increase, the auxiliary brake is easily operated. Therefore, according to the auto cruise control device of the present invention,
When a state of the traveling road that needs to improve the response of deceleration is detected, the auxiliary brake can be operated earlier than usual, and traveling safety can be improved.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram illustrating an entire configuration of an auto cruise control device according to the present embodiment to which the present invention is applied.

As shown in FIG. 1, the automatic cruise control device according to the present embodiment detects a position of an object in front of the vehicle and a relative distance to the object, and a scanning distance measuring device 6, and detects an engine speed. A rotation sensor 7, a steering angle sensor 8 for detecting a change amount of a steering wheel operation angle, a vehicle speed sensor 10 for detecting a signal corresponding to a rotation speed of a wheel, and an auto cruise (general term for inter-vehicle cruise and constant speed cruise) to be described later.
Control switch 11 for inputting various commands for the control of the vehicle, an operation detection switch 13 for detecting an acceleration operation, a deceleration operation, and the like by a driver, set values and operation states related to auto cruise control, sensor abnormalities, and the like. , An exhaust brake control unit 18a for driving and controlling a well-known exhaust brake and a retarding device (hereinafter referred to as an auxiliary brake when collectively referred to) for generating a braking force, and a retarding brake. A brake control unit 18 comprising control units 18b and 18c; an engine output control unit 20 for adjusting an engine output by controlling a fuel injection amount to the engine; a scanning distance measuring device 6, a rotation sensor 7, and a steering angle described above. Sensor 8, vehicle speed sensor 10, cruise control switch 11, operation detection switch And a computer 4 for performing a display control of the control and display unit 14 of the engine output control unit 20 and the brake control unit 18 based on various signals from the pitch 13.

In this embodiment, the scanning distance measuring device 6 is the preceding vehicle information detecting means, the rotation sensor 7, the steering angle sensor 8 and the vehicle speed sensor 10 are the own vehicle information detecting means, the brake control section 18 and the engine output control section. Reference numeral 20 corresponds to the driving force adjusting means. Among them, the scanning rangefinder 6 is
A transmitting / receiving unit 6 for transmitting a laser beam so as to scan a predetermined angle range in front of the vehicle and receiving the reflected light;
a and a distance / angle calculator 6b for detecting the relative speed and position (distance, azimuth) of a forward object based on the time from when the transmitting / receiving unit 6a transmits the laser beam to when the reflected light is received. Have. Such a device is already well known and will not be described in detail. However, the device is not limited to a device using a laser beam, but may use a radio wave such as a microwave or an ultrasonic wave.

The operation detection switch 13 includes a brake switch 13a for detecting a manual operation of a foot brake, an exhaust brake, and a retarding device, and an accelerator switch 13b for detecting an operation of an accelerator. In the case of a vehicle equipped with a manual transmission, a clutch switch for detecting a shift-up or shift-down operation of a clutch is further included.

Further, the cruise control switch 11
Is a main switch 11a for setting and changing the operation mode to an inter-vehicle mode capable of executing an inter-vehicle cruise or a constant speed mode capable of executing a constant-speed cruise, and a target vehicle speed when the vehicle itself is pressed. The set switch 11b for starting cruise control (inter-vehicle cruise in the inter-vehicle mode, constant speed cruise in the constant speed mode) and the accelerator pedal and the brake pedal are operated according to the operation mode at that time. The resume switch 11c for resuming the cruise control temporarily released by the operation, the cancel switch 11d for suspending the cruise control being executed, and the inter-vehicle cruise control for setting the distance between the preceding vehicle and the preceding vehicle. And an inter-vehicle switch 11e.

Next, the computer 4 includes a CPU, an RO,
It is a well-known device mainly composed of an M, a RAM, and an input / output interface (I / O) circuit, and further includes various drive circuits and detection circuits. Since these hardware configurations are general, detailed description is omitted. The computer 4 includes a power switch (not shown), and power is supplied by an ON operation of the power switch to start predetermined processing.

Here, the auto cruise control processing executed by the computer 4 will be described with reference to FIGS. The computer 4 constantly monitors the output of the steering angle sensor 8 in parallel with the auto cruise control process.
A relative steering angle (hereinafter, referred to as angle data) is calculated by integrating the detected value (a change amount of the steering angle),
A process for storing the steering angle in the memory at the steering angle storage address, a process for calculating the speed Vn and the acceleration ATr of the own vehicle based on the detection signal of the vehicle speed sensor 10 and storing them in the vehicle speed storage address in the memory, and a cruise control Switch 1
In response to the operation 1, the switch monitoring process for setting the operation mode of the auto cruise, the target vehicle speed, the target inter-vehicle distance, and performing the state transition of the operation state is also executed.

When the auto cruise control process is started,
As shown in FIG. 2, first, in step (hereinafter simply referred to as “S”) 110, it is determined whether or not the target vehicle speed is set. If the target vehicle speed is not set, the process is terminated as it is. On the other hand, if it is determined that the target vehicle speed has been set, the process proceeds to S120.

The target vehicle speed is controlled by the main switch 11a.
When the set switch 11b is operated in a state in which the operation mode is set to the inter-vehicle mode or the constant speed mode, the setting is performed (reset if already set), and the vehicle speed stored in the vehicle speed storage address at that time is set. Is the target vehicle speed. This target vehicle speed is released when the setting of the operation mode is canceled.

In S120, it is determined whether or not the automatic cruise control is in the temporarily released state. If the state is in the temporarily released state, the process is terminated as it is, and if not, the process proceeds to S130. The temporary release state is a state to which a transition is made when the driver performs an accelerator operation and a brake operation during execution of the cruise control. The temporary release state is a resume switch 11c or a set switch 11c.
It is released by operating b.

In S130, it is determined whether or not the currently set operation mode is the inter-vehicle mode. If the operation mode is the inter-vehicle mode, the process proceeds to S140 to select a target vehicle for performing inter-vehicle cruise. First, based on the angle data stored in the steering angle storage address, a curve radius estimation value Rload representing the degree of turning of the road on which the vehicle is traveling is calculated.

In the following S150, the scanning distance measuring device 6
, The relative speed Vr with the preceding vehicle, the following distance D,
The vehicle speed Vn calculated based on the detection value of the vehicle speed sensor 10 and stored in the vehicle speed storage address, and the previous S140
The preceding vehicle located in the road area estimated from the curve radius estimation value Rload based on the curve radius estimation value Rload calculated in and the closest position among the preceding vehicles traveling in the same direction as the own vehicle. Is selected as the target vehicle.

At S160, it is determined whether or not the target vehicle exists, that is, whether or not the preceding vehicle to be targeted has been selected at S140. If the target vehicle exists, the process proceeds to S170 and proceeds to S170. After executing an inter-vehicle cruise control process for calculating an acceleration command or a deceleration command (hereinafter collectively referred to as an acceleration / deceleration command) for maintaining an appropriate inter-vehicle distance with the vehicle, the process ends.

On the other hand, if it is determined in S130 that the current operation mode is not the inter-vehicle mode, that is, it is the constant speed mode, or if it is determined in S160 that the target vehicle does not exist, the process proceeds to S180. After shifting to a constant speed cruise control process for calculating an acceleration / deceleration command for causing the own vehicle to travel at a constant speed at the target vehicle speed, the process ends.

In accordance with the acceleration / deceleration command calculated in the inter-vehicle cruise control process and the constant speed cruise control process, the engine output control unit 20 controls the fuel injection amount to the engine, and the brake control unit 18 operates. By controlling the type and number of auxiliary brakes, the engine output and the braking force are automatically adjusted independently of the driver's operation, and the auto cruise is executed.

That is, in this processing, the inter-vehicle cruise or the constant-speed cruise is executed according to the set operation mode. If the target vehicle does not exist even during the inter-vehicle cruise, the constant-speed cruise is performed. Have been run. Next, the inter-vehicle cruise control processing executed in S170 will be described with reference to the flowchart shown in FIG.

When this process is started, first, in S210, a target inter-vehicle time Td is set based on the setting of the inter-vehicle switch 11e, and in S220, the target inter-vehicle time Td is set.
d [s], the inter-vehicle distance D [m] detected by the scanning distance measuring device 6, and the own vehicle speed Vn [km / h] detected by the vehicle speed sensor 10 and stored in the vehicle speed storage area. Based on the equation (1), an inter-vehicle time deviation ΔT [s] is calculated.

ΔT = D × 3.6 / Vn−Td (1) The numerical value 3.6 is a constant for converting the unit of the speed Vn from [km / h] to [m / s]. . Following S23
At 0, a target value (target acceleration or target deceleration) AT is obtained based on the inter-vehicle time deviation ΔT calculated in S220 and the relative speed Vr with respect to the target vehicle detected by the scanning distance measuring device 6. . Note that the target value AT is determined using a target value setting map stored in the memory in advance.

FIG. 4 is an explanatory diagram showing the setting contents of the target value setting map. That is, in the target value setting map, the actual inter-vehicle time (D × 3.6 / Vn) is equal to the target inter-vehicle time Td (ΔT = 0), and the vehicle travels at the same speed as the target vehicle (Vr = 0). Is set as zero, the target value AT is set to zero, the inter-vehicle distance to the target vehicle is too far (ΔT> 0), and the own vehicle is moving away from the target vehicle (Vr> 0). ), The greater the degree (the absolute value of the inter-vehicle time deviation ΔT and the relative speed Vr), the larger the positive target value (ie, the target acceleration) is set, and conversely, the inter-vehicle distance to the target vehicle becomes too close. (△ T <
0) and when the vehicle is approaching the target vehicle (Vr <
0), the larger the degree, the larger the negative target value (ie, the target deceleration) is set.

At S240, a gradient correction value calculation process for calculating a correction coefficient K0 for correcting the target value AT set at S230 according to the gradient of the traveling road is executed. A curve correction value calculation process for calculating a correction coefficient K3 for correcting the target value AT according to the degree of curve of the traveling road is executed, and the process proceeds to S260.

In S260, a corrected target value ATh is calculated by using the equation (2) based on the correction coefficients K0 and K3 set in S240 and S250, and further in S270, the corrected target value ATh is calculated. And the actual acceleration AT of the vehicle
Based on r, the acceleration deviation △ AT is calculated using the equation (3).

ATh = AT × K0 × K3 (2) ΔAT = ATh−ATr (3) In subsequent S280, an acceleration / deceleration command to the engine output control unit 20 is calculated based on the integral value of the acceleration deviation ΔAT. In step S290, an output adjustment command VLc is generated as an acceleration / deceleration command to the brake control unit 18 in accordance with the magnitude of the acceleration deviation △ AT, for example, △ AT <−1.
If 5 km / h / s, only the exhaust brake is operated. If △ AT <−2.0 km / h / s, only one retarding device is operated in addition to the exhaust brake.
If △ AT <−2.5 km / h / s, an auxiliary brake operation command BC for operating all auxiliary brakes, that is, an exhaust brake and two retarding devices, is generated.

Finally, in S300, the output adjustment command VLc generated in S280 is input to the engine output control unit 20 as an acceleration / deceleration command, and the auxiliary brake operation command BC generated in S290 is brake-controlled. The input is made to the section 18 and this processing ends.

That is, in the present process, the target value AT is obtained based on the inter-vehicle time deviation ΔT and the relative speed Vr, and the correction coefficient K0, K0, which is set according to the gradient of the traveling road and the degree of turning.
The target value AT is corrected using K3, and the driving force of the own vehicle is controlled based on the corrected target value ATh.

FIG. 5 is an explanatory diagram showing the contents of control in this processing, where "S" represents differentiation. Here, details of the gradient correction value calculation process executed in S240 are described below.
This will be described with reference to the flowchart shown in FIG.

When this process is started, as shown in FIG. 6, first, in S310, the fuel injection amount necessary when traveling on a flat road is determined from the engine speed detected by the rotation sensor 7. And doubling the estimated maximum fuel injection amount F
Set as m. In S320, the engine load L is calculated by using the equation (4) based on the estimated maximum fuel injection amount Fm and the actual fuel injection amount Fr detected by the engine output control unit 20.

L = Fr / Fm × 100 [%] (4) That is, the engine load L is 50% when the own vehicle is traveling on a flat road, and becomes 1 when the load becomes larger than that.
It approaches 00%, and conversely, 0% when the load becomes smaller.
Approach.

At S330, a running resistance index N is determined based on the engine load L calculated at S320 and the actual acceleration ATr stored in the vehicle speed storage area. The running resistance index is determined using a running resistance index setting map stored in a memory in advance.

FIG. 7 is an explanatory diagram showing the contents of the running resistance index setting map. That is, in the running resistance index setting map, the engine load L is 50% and the running speed is constant (AT
r = 0), or when acceleration or deceleration corresponding to the engine load L is performed, 50 is set as the running resistance index N, and although the engine load L is larger than 50%, In a case where acceleration corresponding to the engine load L is not obtained or the vehicle is decelerating, it is assumed that the running resistance is large, and the running resistance index N becomes larger as the engine load L becomes larger and the acceleration ATr becomes smaller. If the value is set to a large value (50 <N ≦ 100), and conversely the engine load L is smaller than 50%, the deceleration corresponding to the engine load L cannot be obtained or the vehicle is accelerating. Means that the running resistance index N is set to a smaller value (0 ≦ N <50) as the engine load L is smaller and the acceleration ATr is larger, assuming that the running resistance is smaller. There.

After the running resistance index N is set in this way, in the following S340, it is determined whether or not the target value AT set in the previous S230 is a positive value. For example, if the target acceleration is set as the target value AT, the process shifts to S350, and the correction coefficient K0 is obtained by using the gradient acceleration adjustment map stored in the memory in advance, and this processing ends. On the other hand, when it is determined that the target value AT is not a positive value, that is, when the target deceleration is set as the target value AT, the process proceeds to S360 and the gradient deceleration adjustment stored in the memory in advance is performed. The correction coefficient K0 is obtained by using the map, and the process ends.

FIG. 8A is an explanatory diagram showing the contents of a gradient acceleration adjustment map, and FIG. 8B is a diagram showing the contents of a gradient deceleration adjustment map. That is, in the gradient acceleration adjustment map,
When the running resistance is normal (N = 50), the correction coefficient K0
Is set to 1.0, and the running resistance is large (50 <N ≦ 1
00), the correction coefficient K0 is set to a value larger than 1.0 (however, 1.0 <K0 ≦ 1.5) as the running resistance increases, and when the running resistance is small (0 ≦ N <50), As the running resistance decreases, the correction coefficient K0 is set to a value smaller than 1.0 (provided that 0.5 ≦ K0 <1.0).

On the other hand, in the gradient deceleration adjustment map, when the running resistance is normal (N = 50), the correction coefficient K0 is set to 1.0, and the running resistance is large (50 <N ≦ 10).
0), the correction coefficient K0 becomes 1.
It is set to a value smaller than 0 (however, 0.5 ≦ K0 <1.0), the running resistance is small (0 ≦ N <50), and the correction coefficient K
0 is a value larger than 1.0 (provided that 1.0 <K0 ≦ 1.
5).

That is, according to this processing, when the vehicle is traveling on a downhill with a small running resistance, if the target value AT is a positive value (ie, the target acceleration), the correction coefficient K0 becomes a value smaller than 1.0. Since the target acceleration is set, the target acceleration is corrected so as to decrease, while the target value AT is negative (that is, the target deceleration).
In the case of, the correction coefficient is set to a value larger than 1.0, so that the target deceleration is corrected so as to increase.

Conversely, when the vehicle is traveling on an uphill with a large running resistance, the target value AT is a positive value (that is, the target acceleration).
, The correction coefficient K0 is set to a value larger than 1.0, so that the target acceleration is corrected so as to increase. On the other hand, when the target value AT is a negative value (that is, the target deceleration),
Since the correction coefficient is set to a value smaller than 1.0, the target deceleration is corrected so as to decrease.

Next, the details of the curve correction value calculation processing executed in S250 will be described with reference to the flowchart shown in FIG. When the present process is started, as shown in FIG. 9, first in S410, it is determined whether or not the target value AT set in the previous S230 is a positive value. That is, if the target deceleration is set as the target value AT, the present process is terminated as it is. On the other hand, the target value AT
Is determined to be a positive value, that is, if the target acceleration is set as the target value AT, the process proceeds to S420, where the curve radius estimation value Rload calculated in the previous S140 is read, and in the subsequent S430, Setting a correction coefficient K3 using a curve acceleration adjustment map stored in a memory in advance;
This processing ends.

FIG. 10 is an explanatory diagram showing the contents of the curve acceleration adjustment map. That is, in the curve acceleration adjustment map, when the estimated degree of bending of the traveling road is relatively gentle (Rload ≧ 800 [m]), the correction coefficient K3 is set to 1.0, and the estimated traveling road is adjusted. Is relatively steep (Rload ≦ 500 [m]), the correction coefficient K3 is set to 0.1, and if it is intermediate between these (800 [m]>Rload> 500 [m]). ), The correction coefficient K3 is set to 0.5.

That is, according to this processing, when the vehicle is traveling on a curve that is steep more than a certain degree, the correction coefficient K3 is set to 1.0.
Since the target acceleration is set to a smaller value, the target acceleration is corrected so as to decrease. In this embodiment, S230 corresponds to a target value calculating unit. Also,
S310 to S330 correspond to the running resistance estimating means, and S140 corresponds to the curve estimating means, that is, they correspond to the traveling road state estimating means. Further, S340 to S360 and S260 correspond to gradient correction means, and S410 to S430 and S260 correspond to curve correction means, that is, they correspond to target value correction means.

As described above, according to the auto-cruise control device of the present embodiment, the target acceleration (positive target value AT) is reduced on a downhill where acceleration is easy and deceleration is difficult (ie, running resistance is small). , Target deceleration (negative target value A
T), the target acceleration (positive target value AT) is increased and the target deceleration (negative target value) is increased on an uphill which is difficult to accelerate and decelerates (ie, has a large running resistance). AT) is reduced, and the amount of increase or decrease of the target value AT is changed according to the magnitude of the gradient (that is, the running resistance).

At the same time, for a curve that is steeper than a certain degree such that the driver does not desire acceleration, the target acceleration (positive target value AT) is corrected so as to decrease. Therefore,
According to the auto cruise control device of the present embodiment, almost constant acceleration / deceleration feeling can be always obtained regardless of the gradient of the traveling road, and acceleration that is contrary to the driver's intention due to a sharp curve or the like is performed. Therefore, a good driving feeling can always be ensured.

Further, according to the auto cruise control device of the present embodiment, when the target deceleration is corrected to increase, that is, on a downhill where it is difficult to decelerate, the absolute value of the acceleration deviation ΔAT is corrected by the correction. Since it increases, the auxiliary brake is operated earlier than usual, and the safety of traveling can be ensured.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an overall configuration of an auto cruise control device according to an embodiment.

FIG. 2 is a flowchart illustrating an auto cruise control process executed by a computer.

FIG. 3 is a flowchart showing details of an inter-vehicle cruise control process executed in step 170 of FIG. 2;

FIG. 4 is an explanatory diagram showing the contents of a target value setting map.

FIG. 5 is a block diagram showing a list of control contents of an inter-vehicle cruise control process.

FIG. 6 is a flowchart illustrating a gradient correction value calculation process executed in step 240 of FIG. 3;

FIG. 7 is an explanatory diagram showing the contents of a running resistance index setting map.

FIG. 8 is an explanatory diagram showing the contents of a gradient acceleration adjustment map and a gradient deceleration adjustment map.

FIG. 9 is a flowchart illustrating a curve correction value calculation process executed in step 250 of FIG. 3;

FIG. 10 is an explanatory diagram showing the contents of a curve acceleration adjustment map.

[Explanation of symbols]

4: Computer 6: Scanning rangefinder
6a: transmitting / receiving unit 6b: distance / angle calculating unit 7: rotation sensor
8 steering angle sensor 10 vehicle speed sensor 11 cruise control switch 11a main switch 11b set switch 11c resume switch 11d cancel switch 11e inter-vehicle switch 13 operation detection switch 13a brake switch 13b accelerator switch 14 display Unit 18: Brake control unit 18a: Exhaust brake control unit 18b, 18ca: Retarding brake control unit 20: Engine output control unit

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI F02D 29/02 301 F02D 29/02 301D (72) Inventor Shigeru Hirayama 3-1-1, Hinodai, Hino-shi, Tokyo Hino Motors, Inc. In company

Claims (4)

[Claims] A vehicle information detecting means for detecting a behavior of the own vehicle including at least a speed and an acceleration; a preceding vehicle information detecting means for detecting a relative position and a speed of the preceding vehicle with respect to the own vehicle; Driving force adjusting means for adjusting the driving force transmitted to the wheels without operating the driver; and, based on the detection results of the own vehicle information detecting means and the preceding vehicle information detecting means, maintaining the target inter-vehicle distance and the own vehicle. Target value calculating means for obtaining a target acceleration or a target deceleration for causing the vehicle to follow the preceding vehicle, and the actual acceleration detected by the own-vehicle information detecting means so as to match the target acceleration or the target deceleration. An auto cruise control device comprising: a driving force control means for controlling the driving force adjusting means; and a state of a traveling road on which the own vehicle is traveling is estimated based on a detection result of the own vehicle information detecting means. And a target value correcting means for increasing or decreasing the target acceleration or the target deceleration obtained by the target value calculating means based on the estimation result of the traveling road state estimating means. Auto cruise control device characterized. 2. The auto cruise control device according to claim 1, wherein the own vehicle information detecting means detects an engine speed and a fuel injection amount as a behavior of the own vehicle, and further comprises the traveling road state estimating means. However, as the engine load determined from the relationship between the engine speed and the fuel injection amount is smaller, and as the actual acceleration is larger, the running resistance estimating means for estimating that the running resistance of the vehicle based on the gradient of the running path is smaller. An automatic cruise system, wherein the target value correction means includes a slope correction means for decreasing the target acceleration or increasing the target deceleration as the traveling resistance estimated by the traveling resistance estimating means decreases. Control device. 3. The auto-cruise control device according to claim 1, wherein the own-vehicle information detecting means detects a steering angle of a steering as a behavior of the own vehicle, and further includes the traveling-path state estimating means. Has a curve estimating means for estimating the degree of curve of the traveling path based on the steering angle, and the target value correcting means sets the target as the degree of curve of the traveling path estimated by the curve estimating means increases. An automatic cruise control device comprising a curve correcting means for reducing the target acceleration obtained by the value calculating means. 4. The auto cruise control device according to claim 1, wherein the driving force adjustment unit includes an auxiliary brake for adjusting a braking force, and the driving force control unit includes: An automatic cruise control device, wherein the auxiliary brake is actuated when a deviation between the target deceleration and the actual acceleration is greater than a preset operation threshold value.