JP4061890B2 - Inter-vehicle distance control device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an inter-vehicle distance control device that controls an inter-vehicle distance from a preceding vehicle by controlling a traveling state of the host vehicle.
[0002]
[Prior art]
When there is no preceding vehicle, the vehicle travels according to the traveling speed set by the occupant. When there is a preceding vehicle, the inter-vehicle distance from the preceding vehicle is detected, and the inter-vehicle distance and the host vehicle are lower than the speed set by the occupant. An inter-vehicle distance control device has been proposed in which traveling control is performed in accordance with the relative speed between the vehicle and the preceding vehicle. Sensors such as a laser radar, a millimeter wave radar, and a CCD camera are used to detect the preceding vehicle.
[0003]
[Problems to be solved by the invention]
By the way, in the inter-vehicle distance control device as described above, for example, if the preceding vehicle detection sensor loses sight of the preceding vehicle on a curved road or a slope, so-called lost, the inter-vehicle distance cannot be detected. It is common to stop driving. However, when the preceding vehicle following traveling is suddenly stopped during the preceding vehicle following traveling in this way, the passenger feels uncomfortable.
[0004]
In order to solve the above-described problems, an object of the present invention is to provide an inter-vehicle distance control device that makes it difficult for a preceding vehicle detection sensor to lose sight of a preceding vehicle on a curved road, a slope, or the like and that can continue to follow the preceding vehicle. is there.
[0005]
[Means for Solving the Problems]
  In order to achieve the above object, an inter-vehicle distance control apparatus according to claim 1 of the present invention controls inter-vehicle distance detection means for detecting an inter-vehicle distance between the host vehicle and a preceding vehicle, and controls the speed of the host vehicle. An inter-vehicle distance control means for controlling the inter-vehicle distance between the host vehicle and the preceding vehicle to match the target inter-vehicle distance, a travel path detection means for detecting a travel path from a road shape ahead of the own vehicle, and the travel path detection means A host vehicle position detecting means for detecting the position of the host vehicle on the travel path detected in step (b), a travel path detected by the travel path detecting means, and a host vehicle on the travel path detected by the host vehicle position detecting means. A preceding vehicle follow-up continuable distance detecting means for detecting a line-of-sight distance that can be detected by the preceding vehicle as a preceding vehicle follow-up continuable distance based on the position of the vehicle. Follow continuable distance based on the preceding vehicle following continuable distance detected by the detection means and a target inter-vehicle distance setting means for setting the target inter-vehicle distanceThe preceding vehicle follow-up continuable distance detecting means includes preceding vehicle detection continuable acceleration detecting means for detecting an acceleration necessary for continuing to detect the preceding vehicle as a preceding vehicle detection continuable acceleration, and the inter-vehicle distance control means is The preceding vehicle in which the preceding vehicle detection continuable acceleration detected by the preceding vehicle detection continuable acceleration detecting means is calculated based on the line-of-sight distance that can be detected by the preceding vehicle when traveling along the travel route ahead of the host vehicle. Control the speed of the host vehicle based on the acceleration that can be detected by the preceding vehicle when the target acceleration is greater than the line-of-sight target accelerationIt is characterized by this.
[0006]
The inter-vehicle distance control apparatus according to claim 2 of the present invention is the inter-vehicle distance control device according to claim 1, wherein the target inter-vehicle distance setting means suppresses deceleration of the host vehicle accompanying deceleration of the preceding vehicle. The inter-vehicle distance is set.
According to a third aspect of the present invention, in the inter-vehicle distance control apparatus according to the first or second aspect, the target inter-vehicle distance setting means does not match a traveling route of the preceding vehicle and a traveling route of the host vehicle. The setting of the target inter-vehicle distance based on the preceding vehicle following continuable distance is stopped.
[0007]
According to a fourth aspect of the present invention, in the inter-vehicle distance control device according to the first to third aspects, the preceding vehicle follow-up continuable distance detecting means is detected by the travel route detecting means. A line-of-sight distance that can be detected by a preceding vehicle is detected based on the shape of the travel route when traveling on the travel route ahead of the host vehicle.
According to a fifth aspect of the present invention, in the inter-vehicle distance control device according to the first to third aspects, the preceding vehicle follow-up continuable distance detecting means is detected by the travel route detecting means. A line-of-sight distance that can be detected by a preceding vehicle is detected based on attribute information of the travel route when traveling on the travel route ahead of the host vehicle.
[0008]
  According to a sixth aspect of the present invention, in the inter-vehicle distance control device according to the first to third aspects, the preceding vehicle follow-up continuable distance detecting means can be detected by the inter-vehicle distance detecting means. Based on the inter-vehicle distance between the host vehicle and the preceding vehicle, a line-of-sight distance that can be detected by the preceding vehicle is detected when traveling on the travel route ahead of the host vehicle.
[0009]
  Further, the present invention claims7The inter-vehicle distance control device according to claim 11 to 6In the invention, the preceding vehicle detection continuable acceleration detecting means detects the preceding vehicle detection continuable acceleration necessary for continuously detecting the preceding vehicle according to the speed and acceleration of the preceding vehicle and the speed of the host vehicle. It is characterized by this.
[0010]
【The invention's effect】
  Thus, according to the inter-vehicle distance control apparatus according to claim 1 of the present invention, when the inter-vehicle distance between the host vehicle and the preceding vehicle coincides with the target inter-vehicle distance, the travel route is detected from the road shape in front of the host vehicle. And the line-of-sight distance that the preceding vehicle can detect when traveling along the traveling route ahead of the subject vehicle based on the traveling route and the position of the own vehicle on the traveling route. Is detected as a preceding vehicle following continuation possible distance, and the target inter-vehicle distance is set based on the preceding vehicle following continuation possible distance.For example, when there is a possibility that the preceding vehicle may be lost on a curved road or a slope, If the line-of-sight distance that the preceding vehicle can detect from the shape of the travel route is detected as the preceding vehicle follow-up continuable distance and the target inter-vehicle distance is set based on the preceding vehicle follow-up continuable distance, Since the inter-vehicle distance is the preceding vehicle following continuation distance between both bets preceding vehicle, without lost the preceding vehicle, and can continue the preceding vehicle following cruise.In addition, the acceleration required to continue to detect the preceding vehicle is detected as the preceding vehicle detection continuable acceleration, and the preceding vehicle detection continuable acceleration can be detected when traveling on the travel route ahead of the host vehicle. Since the speed of the host vehicle is controlled based on the preceding vehicle detection continuable acceleration when the preceding vehicle target acceleration calculated based on the line-of-sight distance is greater than or equal to the target vehicle line-of-sight target acceleration, there is a possibility that the preceding vehicle may be lost, for example. Sometimes it is possible not only to see the preceding vehicle, but also to make sure that the preceding vehicle can continue to be detected without losing the preceding vehicle by making the preceding vehicle detection continuable acceleration the target inter-vehicle acceleration. Can be continued.
[0011]
According to the inter-vehicle distance control device of the present invention, since the target inter-vehicle distance is set so as to suppress the deceleration of the host vehicle accompanying the deceleration of the preceding vehicle, the preceding vehicle is not lost. Therefore, the host vehicle does not accelerate carelessly and there is no sense of incongruity.
According to the inter-vehicle distance control device according to claim 3 of the present invention, the target inter-vehicle distance is set based on the preceding vehicle follow-up continuable distance when the traveling route of the preceding vehicle and the traveling route of the host vehicle do not match. Since it is configured to cancel, unnecessary preceding vehicle follow-up traveling can be avoided, for example, when the traveling route of the preceding vehicle and the traveling route of the host vehicle become inconsistent due to a lane change or the like.
[0012]
According to the inter-vehicle distance control device according to claim 4 of the present invention, the line-of-sight distance that the preceding vehicle can detect when traveling on the traveling route ahead of the host vehicle is determined based on the detected shape of the traveling route. Since it is configured to detect, for example, it is possible to accurately detect a line-of-sight distance that can be detected by a preceding vehicle on a curved road or a slope.
According to the inter-vehicle distance control device according to claim 5 of the present invention, the line-of-sight distance that the preceding vehicle can detect when traveling on the traveling route ahead of the host vehicle based on the detected attribute information of the traveling route. For example, the line-of-sight distance on which a preceding vehicle can be detected on a curved road or a slope can be accurately detected together with, for example, map information and travel route information obtained by road-to-vehicle communication.
[0013]
  According to the inter-vehicle distance control device of the present invention, the preceding vehicle is detected when traveling along the travel route ahead of the own vehicle based on the detectable inter-vehicle distance between the own vehicle and the preceding vehicle. Since it is configured to detect possible line-of-sight distance, the line-of-sight distance that can be detected by the preceding vehicle can be accurately detected based on the performance of the inter-vehicle distance detection means such as a laser radar, a millimeter wave radar, or a CCD camera.
[0014]
  Further, the present invention claims7According to the inter-vehicle distance control device according to the present invention, the configuration is such that the preceding vehicle detection continuable acceleration necessary for continuing to detect the preceding vehicle is detected according to the speed and acceleration of the preceding vehicle and the speed of the host vehicle. By making the traveling speed of the host vehicle equal to the traveling speed of the preceding vehicle until the point where the vehicle is lost, the preceding vehicle detection continuable acceleration necessary for continuing to detect the preceding vehicle is accurately determined. Can be detected.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a system configuration diagram showing an embodiment of a vehicle with a preceding vehicle follow-up travel control device to which the inter-vehicle distance control device of the present invention is applied. This vehicle is a rear wheel drive vehicle in which the rear wheels 1RL and 1RR are driving wheels and the front wheels 1FL and 1FR are driven wheels, and the driving torque of the engine 2 is transmitted to the rear wheels 1RL and 1RR via the automatic transmission 3. Is done.
[0016]
The rotation state, torque, output, etc. of the engine 2 can be controlled by the engine control device 11. Specifically, the engine rotation state, torque, output, etc. can be controlled by adjusting the throttle valve opening, idle valve opening, ignition timing, fuel injection amount, fuel injection timing, and the like.
The automatic transmission 3 can be controlled by a transmission control device 12. Specifically, by adjusting the working fluid pressure supplied to the clutch and brake in the automatic transmission 3, the selected gear ratio can be changed to obtain a desired reduction ratio.
[0017]
The wheels 1FL to 1RR are provided with wheel cylinders 4FL to 4RR constituting so-called disc brakes. The wheel cylinders 4FL to 4RR apply a braking force to the wheels 1FL to 1RR by the supplied brake fluid pressure. The braking force applied to each of the wheels 1FL to 1RR can be controlled by the braking fluid pressure control device 13. Specifically, for example, each wheel cylinder 4FL˜ is increased by increasing the brake fluid pressure as in the driving force control device (TCS) or decreasing the brake fluid pressure as in the anti-skid control device (ABS). The braking fluid pressure to 4RR can be adjusted and the braking force to each wheel 1FL-1RR can be controlled. The braking fluid pressure regulated in the braking fluid pressure control device 13 is supplied from a master cylinder 22 that is boosted by depressing the brake pedal 21.
[0018]
In addition, the steering direction, the steering angle, and the steering speed of the steering wheel 5 that is originally steered by the driver, strictly speaking, the steering shaft 6 connected thereto, can be controlled by the steering control device 14. Specifically, the steering direction, the steering angle, and the steering speed can be controlled by adjusting the rotation direction, rotation angle, and rotation speed of the motor 8 connected to the steering shaft 6.
These control devices all control the running state of the vehicle, and as a result, adjust the acceleration / deceleration, longitudinal speed, running direction, lateral speed, turning amount, etc. of the host vehicle to control the running state. can do.
[0019]
Of course, these control devices can operate alone, but the overall function is governed by the automatic travel control device 10 including inter-vehicle distance control and preceding vehicle following travel control. The automatic travel control device 10 performs various arithmetic processes to control the travel state of the vehicle, thereby performing inter-vehicle distance control, preceding vehicle following travel control, and the like.
Further, the vehicle is provided with a CCD camera or the like, for example, a front state detection device 16 for detecting a state in front of the host vehicle, for example, the state of the traveling lane, the presence or absence of a preceding vehicle, or the distance to the preceding vehicle, Wheel speed sensors 17FL to 17RR for detecting a rotational speed of ˜1RR, an acceleration sensor 18 for detecting longitudinal and lateral accelerations generated in the vehicle, a brake fluid pressure sensor 19 for detecting a brake fluid pressure, and an accelerator pedal depression amount are detected. An accelerator opening sensor 20 is provided. Further, this vehicle is provided with a manual switch 9 for inputting a traveling state of the own vehicle, specifically, an inter-vehicle distance from a preceding vehicle, by a driver's manual input. Further, the vehicle is provided with a display and a speaker 23 for presenting the contents of control by the automatic travel control device 10 to an occupant, particularly a driver. The forward state detection device 16 has a function of detecting whether the vehicle ahead of the host vehicle is a preceding vehicle that precedes the same lane as the host vehicle.
[0020]
Further, this vehicle is provided with a host vehicle position detection device 7 such as a so-called GPS (Global Positioning System). A national map information device 15 is built in the own vehicle position detection device 7. Further, in the own vehicle position detection device 7, from the nationwide map information device 15, the surrounding travel route where the host vehicle is traveling and its shape, for example, terrain information such as a radius of a curved road and a slope of a hill, a lane A travel route information device 24 for detecting the environment of the travel route by communicating information with the number, lane width, or environment, so-called infrastructure, is also provided. Further, according to the travel route information device 24, as the travel route attribute information, for example, the approximate line-of-sight distance of the currently traveled travel route can be obtained.
[0021]
Next, calculation processing of the inter-vehicle distance control performed in the automatic travel control device 10 will be described with reference to the flowchart of FIG. This calculation process is executed by a timer interrupt every predetermined sampling time ΔT set to, for example, about 10 msec. In this flowchart, no particular communication step is provided, but the results obtained by the arithmetic processing are updated and stored in the storage device as needed, and necessary information and programs are read from the storage device as needed. Further, the above-described engine control device 11, transmission control device 12, braking fluid pressure control device 13, and steering control device 14 communicate with each other at any time, and necessary information and commands are exchanged bidirectionally at any time.
[0022]
In this calculation process, first, in step S1, the longitudinal acceleration Xg and lateral acceleration Yg detected by the acceleration sensor 18 and the wheel speed Vw detected by the wheel speed sensor 17 are detected._j(J = FL to RR), accelerator opening Acc detected by the accelerator opening sensor 20, braking fluid pressure Pm detected by the braking fluid pressure sensor 19, and set inter-vehicle distance set by the manual switch 9 L₀, The inter-vehicle distance Lx detected by the front state detection device 16, the engine driving torque Tw controlled by the engine control device 11, the own vehicle position detected by the own vehicle position detection device 7, The travel route information detected by the travel route information device 24 is read.
[0023]
Next, the process proceeds to step S2, where the wheel speed Vw read in step S1 is read._jAmong them, the front left and right wheel speeds Vw which are driven wheels_FL, Vw_FRThe traveling speed V of the host vehicle is calculated from the average value.
Next, the process proceeds to step S3, and the current value Lx of the inter-vehicle distance from the preceding vehicle read in step S1._(n)And the previous value Lx_(n-1)And the relative speed dLx between the host vehicle and the preceding vehicle is calculated.
[0024]
Next, the process proceeds to step S4, and the reference target inter-vehicle distance Lc according to the traveling speed V of the host vehicle calculated in step S2.₀Is calculated. Specifically, the travel speed V of the host vehicle is multiplied by a predetermined control gain, and a predetermined control constant is summed. The control gain and the control constant are determined by the manual switch 7 and the set inter-vehicle distance L requested by the driver.₀It can be changed according to.
Next, the process proceeds to step S5, the travel route information read in step S1, the shape of the clogged travel route, the position of the host vehicle, the travel speed V of the host vehicle calculated in step S2, and the step S3. Calculated relative speed dL with the preceding vehicle_XThe distance through which the preceding vehicle can be seen based on the preceding vehicle sight distance L_LCalculate as Specifically, for example, in the case of a curve road, if the preceding vehicle moves ahead of the curve as shown in FIG. 3a, it is impossible to see the preceding vehicle._LAnd In the case of a slope, for example, as shown in FIG. 4a, if the preceding vehicle moves forward from the top of the slope, the preceding vehicle cannot be seen._LAnd The preceding vehicle line-of-sight distance L_LThe line-of-sight distance obtained as attribute information of the travel route information may be used as it is, or may be calculated in more detail with reference to the value.
[0025]
Next, the process proceeds to step S6, where the sensor line-of-sight distance L of the front state detection device 16 such as the CCD camera is detected._SIs calculated. This sensor visibility distance L_SFor example, the standard deviation of the inter-vehicle distance from the preceding vehicle is used as a noise index, and the sensor line-of-sight distance L increases as the noise index increases._SSet to short. In addition, for example, when the distance that can be seen is shortened due to the pitching movement of the vehicle, the distance may be set in consideration thereof.
Next, the process proceeds to step S7, and the preceding vehicle line-of-sight distance L calculated in step S5 is obtained._LIs the sensor line-of-sight distance L calculated in step 6 above._SIt is determined whether or not the following vehicle sight distance L_LIs the sensor visibility distance L_SWhen it is below, it transfers to step S8, and when that is not right, it transfers to step S9.
[0026]
In step S8, the preceding vehicle line-of-sight distance L calculated in step S5 is calculated._LIs the preceding vehicle visibility distance L_LThen, the process proceeds to step S10.
In step S9, the sensor line-of-sight distance L calculated in step S6 is used._SThe preceding vehicle visibility distance L_LThen, the process proceeds to step 10. In step S10, the reference target vehicle speed Vs is as follows.₀Is calculated. Here, first, the relative speed dL between the host vehicle traveling speed V calculated in step S2 and the preceding vehicle calculated in step S3._XIs added to calculate the traveling speed of the preceding vehicle, and a difference value between the traveling speed of the preceding vehicle and the reference target inter-vehicle distance Lc calculated in step S4 and the actual inter-vehicle distance Lx read in step S1. The reference target vehicle speed Vs is calculated by adding the value obtained by multiplying the value by the proportional control gain and the value obtained by multiplying the relative speed dLx calculated in step S3 by the differential gain.₀Is calculated.
[0027]
Next, the process proceeds to step S11, and the preceding vehicle prospect target vehicle speed V is as follows._LIs calculated. Here, first, the relative speed dL between the host vehicle traveling speed V calculated in step S2 and the preceding vehicle calculated in step S3._XTo calculate the traveling speed of the preceding vehicle, and the traveling speed of the preceding vehicle and the preceding vehicle view distance L set in step S8 or step S9._LAnd the actual vehicle distance Lx read in step S1 and the value obtained by multiplying the value obtained by multiplying the proportional control gain by the value obtained by multiplying the relative speed dLx calculated in step S3 by the differential gain. Forecast target vehicle speed V_LIs calculated.
[0028]
Next, the process proceeds to step S12, and the reference target vehicle speed Vs calculated in step S10.₀And the reference target acceleration Xgs by, for example, PID (proportional-differential-integral) control from the difference value with the traveling speed V of the host vehicle calculated in step S2.₀Is calculated.
Next, the process proceeds to step S13, and the preceding vehicle prospect target vehicle speed V calculated in step S11 is obtained._LFrom the difference value with the traveling speed V of the host vehicle calculated in step S2, the preceding vehicle line-of-sight target acceleration Xg by, for example, PID (proportional-differential-integral) control is used._LIs calculated.
[0029]
Next, the process proceeds to step S14, where the acceleration for reaching the vehicle speed equivalent to the preceding vehicle speed and the preceding vehicle speed arrival acceleration Xg are as follows._EIs calculated. That is, for example, on the curved road shown in FIG. 3a, the intersection of the set inter-vehicle distance and the non-line-of-sight area becomes the lost time as shown in FIG. 3b. Further, on the slope shown in FIG. 4a, as shown in FIG. 4b, the intersection of the set inter-vehicle distance and the non-line-of-sight region becomes the lost time. Therefore, if the inter-vehicle distance continues to detect the preceding vehicle by this lost time and the speed is equal to that of the preceding vehicle, the preceding vehicle is not lost thereafter. Therefore, a distance obtained by multiplying the travel distance up to the lost time, that is, the time until the lost time by the current vehicle speed is set as a distance s to the end point of the inter-vehicle distance reduction. Then, the distance s to the end point of shortening the inter-vehicle distance, the traveling speed V of the host vehicle calculated in step S2, and the preceding vehicle prospect target vehicle speed V calculated in step S11._LAnd the preceding vehicle line-of-sight distance L set in step S8 or step S9._L, The preceding vehicle speed arrival acceleration Xg according to the following formula 1_EIs calculated.
[0030]
Xg_E= (V²-V_L ²) / (2 × (s−L_L)) ……… (1)
Next, the process proceeds to step S15, where the preceding vehicle speed arrival acceleration Xg calculated in step S14 is obtained._EIs the preceding vehicle line-of-sight target acceleration Xg calculated in step S13._LIt is determined whether or not the vehicle speed reached acceleration Xg_EIs the preceding vehicle outlook target acceleration Xg_LIf so, the process proceeds to step S16, and if not, the process proceeds to step S17.
[0031]
In step S16, the preceding vehicle speed arrival acceleration Xg calculated in step S14 is calculated._EAccelerating vehicle target acceleration Xg_LThen, the process proceeds to step S18.
In step S17, the preceding vehicle line-of-sight target acceleration Xg calculated in step S13 is calculated._LAs is ahead vehicle prospect target acceleration Xg_LThen, the process proceeds to step S18.
[0032]
In step S18, the preceding vehicle line-of-sight target acceleration Xg set in step S16 or step S17 is set._LIs the reference target acceleration Xgs calculated in step S12.₀That is, the reference target inter-vehicle distance Lc₀It is determined whether or not the acceleration is greater than or equal to the acceleration calculated based on the preceding vehicle prospective target acceleration Xg_LIs the reference target acceleration Xgs₀If so, the process proceeds to step S19, and if not, the process proceeds to step S20.
[0033]
In step S19, it is determined whether or not the host vehicle is traveling in the same lane as the preceding vehicle from the state in front of the host vehicle detected by the forward state detection device 16, and the host vehicle follows the same lane as the preceding vehicle. If the vehicle is traveling, the process proceeds to step S21. If not, the process proceeds to step S20.
In step S21, the preceding vehicle line-of-sight target acceleration Xg_LIs set to the target acceleration Xgs, and then the process proceeds to step S22.
[0034]
In step S20, the reference target acceleration Xgs₀Is set to the target acceleration Xgs, and then the process proceeds to step S22.
In step S22, when the target acceleration Xgs set in step S20 or step S21 is negative, that is, when deceleration is required, a value obtained by multiplying the target acceleration Xgs by a brake specification coefficient, and the step Of the values obtained by multiplying the brake fluid pressure Pm read in S1 by the brake specification coefficient, the larger one is the target brake fluid pressure Pws._jCalculate as The brake specification coefficient is a coefficient determined by, for example, the friction coefficient between the disk rotor pads of each wheel, the wheel cylinder cross-sectional area, the disk rotor effective diameter, the tire rolling radius, and the like.
[0035]
Next, the process proceeds to step S23, and when the target acceleration Xgs set in step S20 or step S21 is positive, that is, when acceleration is required, the target acceleration Xgs is multiplied by a drive system specification variable. The larger one of the value and the value obtained by multiplying the accelerator opening Acc read in step S1 by the drive system variable is calculated as the target drive torque Tes. The drive system specification variable is a variable determined by, for example, gear inertia, reduction ratio, transmission efficiency, engine characteristics, and the like.
[0036]
Next, the process proceeds to step S24, where the target braking fluid pressure Pws calculated in step S22 is obtained._jThe target drive torque Tes calculated in step S23 is output to the braking fluid pressure control device 13, the engine control device 11, and the transmission control device 12, and an information presentation signal for target inter-vehicle distance control is output to the display and After output to the speaker 23, the main program is restored.
As described above, in the present embodiment, the reference target inter-vehicle distance Lc based on the traveling speed V of the host vehicle.₀Reference target acceleration Xgs calculated from₀Is the target vehicle distance L_LThe target vehicle outlook target acceleration Xg calculated from_LWhen larger, the reference target inter-vehicle distance Lc based on the traveling speed V of the subject vehicle.₀Reference target acceleration Xgs calculated from₀By controlling the speed of the host vehicle based on the_XThe reference target inter-vehicle distance L_LThis makes it possible to follow the preceding vehicle in a normal state.
[0037]
On the other hand, the preceding vehicle prospect target inter-vehicle distance L_LThe target vehicle outlook target acceleration Xg calculated from_LIs a reference target inter-vehicle distance Lc based on the traveling speed V of the host vehicle.₀Reference target acceleration Xgs calculated from₀If this is the case, the preceding vehicle line-of-sight target acceleration X_LBy controlling the speed of the host vehicle based on the_XThe preceding vehicle view distance L_LThus, when there is a possibility of losing the preceding vehicle such as a curved road or a slope, it is possible to make the preceding vehicle look less difficult to be lost and to continue the preceding vehicle following traveling. .
[0038]
Further, the preceding vehicle speed arrival acceleration Xg calculated from the distance s to the end point of shortening the inter-vehicle distance necessary for continuing to detect the preceding vehicle._EIs the preceding vehicle prospect target inter-vehicle distance L_LThe target vehicle outlook target acceleration Xg calculated from_LIf this is the case, the preceding vehicle speed arrival acceleration Xg_EAccelerating vehicle target acceleration Xg_LAnd that is the reference target acceleration Xgs₀If this is the case, the preceding vehicle line-of-sight target acceleration X_LThat is, the preceding vehicle speed reaching acceleration Xg_EThe speed of the own vehicle is controlled based on the above. For example, as shown in FIG. 5, if the current inter-vehicle distance is maintained, the time t_SWhen the preceding vehicle is lost at time t, as shown by the thick line in the figure, the time t_SThe preceding vehicle can be prevented from being lost by reducing the distance between the preceding vehicle and the traveling speed equivalent to the preceding vehicle speed. When there is no possibility of losing the preceding vehicle, the distance to the previous inter-vehicle distance, that is, the set inter-vehicle distance is restored.
[0039]
Thus, for example, as shown in FIG. 6a, when there is a possibility that the preceding vehicle may be lost on a curved road, the distance between the host vehicle and the preceding vehicle is reduced before the preceding vehicle moves ahead of the curve. As a result, even if the preceding vehicle moves ahead of the curve, it can be prevented from being lost, that is, the preceding vehicle can be continuously detected. Similarly, as shown in FIG. 6b, for example, when there is a possibility that the preceding vehicle may be lost on the slope, the distance between the host vehicle and the preceding vehicle is reduced before the preceding vehicle moves ahead of the slope. As a result, even if the preceding vehicle moves further down the slope, it can be prevented from being lost, that is, the preceding vehicle can be continuously detected. Generally, the vehicle decelerates before a curved road or on the top of a slope. When trying to maintain the inter-vehicle distance, the host vehicle decelerates as the preceding vehicle decelerates. However, reducing the inter-vehicle distance by using a larger acceleration as described above suppresses the deceleration of the host vehicle accompanying the deceleration of the preceding vehicle, and accelerates the actual vehicle so as not to be lost. There is no sense of incongruity.
[0040]
On the other hand, when the preceding vehicle changes lanes and the host vehicle is not traveling in the same lane as the preceding vehicle, the reference target acceleration Xgs₀Based on the vehicle speed, that is, the preceding vehicle line-of-sight target acceleration Xg_LBy stopping the control of the vehicle speed based on the vehicle, the preceding vehicle that does not need to follow is not unnecessarily followed.
In the above-described embodiment, so-called feedback control is used for the part that controls the speed of the host vehicle based on the inter-vehicle distance from the preceding vehicle. For example, the November 1999 (p98 to p103, “Automatic Inter-vehicle Control” A combination of feedback control and feedforward control may be applied as described in “Development of System”, Iijima et al.). That is, the present invention relates to a change in the target inter-vehicle distance, and various control laws can be applied to control the inter-vehicle distance.
[Brief description of the drawings]
FIG. 1 is a vehicle configuration diagram showing an example of a vehicle with preceding vehicle follow-up travel control equipped with an inter-vehicle distance control device of the present invention.
FIG. 2 is a flowchart showing a calculation process for inter-vehicle distance control performed by the automatic travel control device of FIG. 1;
FIG. 3 is an explanatory diagram when a preceding vehicle is lost on a curved road.
FIG. 4 is an explanatory diagram when a preceding vehicle is lost on a slope.
FIG. 5 is an explanatory diagram of a preceding vehicle speed arrival acceleration.
FIG. 6 is an explanatory diagram of the action caused by the preceding vehicle speed arrival acceleration.
[Explanation of symbols]
1FL to 1RR are wheels
2 is the engine
3 is an automatic transmission
4FL to 4RR are wheel cylinders
5 is the steering wheel
6 is the steering shaft
7 is an inter-vehicle communication device
8 is a motor
9 is a manual switch
10 is an automatic travel control device
11 is an engine control device
12 is a transmission control device.
13 is a brake fluid pressure control device
14 is a steering control device
15 is a nationwide map information device
16 is a front state detection device
17FL to 17RR are wheel speed sensors
18 is an acceleration sensor
19 is a brake fluid pressure sensor
20 is an accelerator opening sensor.
21 is a brake pedal
22 is a master cylinder
23 is a display and a speaker
24 is a travel route information device

Claims (7)

Inter-vehicle distance detection means for detecting the inter-vehicle distance between the host vehicle and the preceding vehicle, and the inter-vehicle distance for controlling the inter-vehicle distance between the host vehicle and the preceding vehicle to match the target inter-vehicle distance by controlling the speed of the host vehicle. Control means; travel route detection means for detecting a travel route from a road shape ahead of the host vehicle; host vehicle position detection means for detecting a position of the host vehicle on the travel route detected by the travel path detection means; Based on the travel route detected by the travel route detection means and the position of the own vehicle on the travel route detected by the own vehicle position detection means, the preceding vehicle can be detected when traveling on the travel route ahead of the own vehicle. Based on the preceding vehicle followable continuable distance detecting means for detecting the line-of-sight distance as the preceding vehicle followable continuable distance, and the preceding vehicle followable continuable distance detected by the preceding vehicle followable continuable distance detecting means A target inter-vehicle distance setting means for setting a serial target following distance, the preceding vehicle following continuable distance detecting means detects the acceleration necessary to continue to detect the preceding vehicle as the preceding vehicle detection continuable acceleration preceding vehicle An acceleration detecting means capable of detecting continuation, wherein the inter-vehicle distance control means detects when the preceding vehicle detection continuable acceleration detected by the preceding vehicle detection continuable acceleration detecting means travels along a travel route ahead of the host vehicle. An inter-vehicle distance control device that controls the speed of the host vehicle based on the preceding vehicle detection continuable acceleration when the vehicle is equal to or more than a preceding vehicle line-of-sight target acceleration calculated based on a detectable line-of-sight distance. .   2. The inter-vehicle distance control device according to claim 1, wherein the target inter-vehicle distance setting unit sets the target inter-vehicle distance so as to suppress deceleration of the host vehicle accompanying deceleration of the preceding vehicle.   The target inter-vehicle distance setting means stops setting the target inter-vehicle distance based on the preceding vehicle follow-up continuable distance when the travel route of the preceding vehicle does not match the travel route of the host vehicle. Or the inter-vehicle distance control device according to 2.   The preceding vehicle follow-up continuable distance detecting means detects a line-of-sight distance that the preceding vehicle can detect when traveling on the traveling route ahead of the host vehicle based on the shape of the traveling route detected by the traveling route detecting means. The inter-vehicle distance control device according to any one of claims 1 to 3, wherein   The preceding vehicle follow-up continuable distance detecting means is configured to determine a line-of-sight distance that the preceding vehicle can detect when traveling on the traveling route ahead of the host vehicle based on the attribute information of the traveling route detected by the traveling route detecting means. The inter-vehicle distance control device according to any one of claims 1 to 3, wherein the inter-vehicle distance control device is detected.   The preceding vehicle follow-up continuable distance detecting means can detect the preceding vehicle when traveling on the traveling route ahead of the own vehicle based on the inter-vehicle distance between the own vehicle and the preceding vehicle that can be detected by the inter-vehicle distance detecting means. The inter-vehicle distance control device according to any one of claims 1 to 3, wherein a clear line-of-sight distance is detected. The preceding vehicle detection continuable acceleration detecting means detects a preceding vehicle detection continuable acceleration necessary for continuously detecting the preceding vehicle according to the speed and acceleration of the preceding vehicle and the speed of the host vehicle. The inter-vehicle distance control device according to any one of claims 1 to 6 .

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