JP2008290600A - Travel control device of vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a means for avoiding collision with a forward vehicle without increasing the risk of the collision with a following vehicle. <P>SOLUTION: The travel control device is equipped with a means (S3) which calculates the risk of the collision with the following vehicle when the brake is applied according to a setting value from a measurement value of an inter-vehicle distance and the relative speed from the forward vehicle, a measurement value of an inter-vehicle distance and the relative speed from the following vehicle, and the setting value of the distance for automatically applying the brake and a braking force for being automatically applied, the means (S5) which compensates the setting value of the distance for automatically applying the brake and the braking force for being automatically applied so that the risk becomes not larger than the predetermined level when the arithmetic value of the risk is higher than the predetermined level, and the means (S6, S8) which apply the brake with the braking force for being automatically applied after compensation when the measurement value of the inter-vehicle distance from the forward vehicle becomes not larger than the distance for automatically applying the brake after compensation. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a vehicle travel control device. In particular, the present invention relates to a control system for avoiding a collision between vehicles.

  As for the control system for avoiding collision between vehicles, if the degree of danger exceeds the predetermined level while calculating the degree of danger of collision with the preceding car from the measured distance and relative speed with the preceding car, There is something that is designed to apply braking. In this case, although the collision with the preceding vehicle can be avoided by the braking applied automatically, there is a possibility that the collision with the following vehicle may be caused depending on the traveling state.

In Patent Document 1, a means for calculating a safe inter-vehicle distance from a relative speed with a preceding vehicle and a traveling speed (vehicle speed) of the own vehicle, based on a comparison between a measured value of the inter-vehicle distance with the preceding vehicle and a safe inter-vehicle distance. A device is disclosed that includes means for calculating the risk of a collision with a preceding vehicle, and means for generating an alarm corresponding to the risk for the following vehicle.
JP-A-8-160138

  An object of this invention is to provide the control system for avoiding the collision with a preceding vehicle, without raising the danger of a collision with a following vehicle, based on such a prior art.

  The present invention provides a means for measuring an inter-vehicle distance and a relative speed with a preceding vehicle, a means for measuring an inter-vehicle distance and a relative speed with a rear vehicle, and a limit distance that can avoid a collision with the preceding vehicle by a driver's operation. Means for setting the braking distance and the braking force to be automatically applied at that time, the measured value of the inter-vehicle distance and relative speed with the preceding vehicle, the measured value of the inter-vehicle distance and relative speed with the following vehicle, and automatic A means for calculating the risk of collision with the following vehicle when the braking is applied according to the set value, and the calculated value of the risk is When the level is higher than the predetermined level, the braking distance and the braking force to be applied automatically so that the degree of risk falls below the predetermined level. A means for correcting the set value of the vehicle, a means for calculating the distance to generate an alarm for the driver of the following vehicle based on the automatically applied braking distance after the correction, and a measured value of the inter-vehicle distance from the preceding vehicle A means for generating an alarm to the driver of the following vehicle when the distance is less than the distance that should be generated, and when the measured value of the inter-vehicle distance of the preceding vehicle is less than the corrected automatic braking distance, Means for braking with power is provided.

  In the present invention, the distance to automatically apply the braking and the braking force to be applied automatically at that time are set as the limit distance that can avoid the collision with the preceding vehicle by the driver's operation, and the braking is set to the set value (automatically The degree of danger of a collision with the following vehicle when applied according to the braking distance (automatic braking force applied to the vehicle) is calculated. When the calculated value of the degree of risk is higher than a predetermined level, the distance for automatically applying the braking and the set value of the braking force to be applied automatically are corrected so that the degree of risk is not more than the predetermined level. That is, when the calculated value of the danger level is higher than the predetermined level, the braking distance is automatically increased, the braking force automatically applied is corrected to be small, and the danger level is suppressed to a predetermined level or less.

  The distance to generate an alarm is calculated based on the corrected automatic braking distance, and if the measured value of the inter-vehicle distance from the preceding vehicle is less than the distance to generate the alarm, An alarm occurs. For this reason, the driver | operator of a subsequent vehicle can be provided with the time allowance for the collision avoidance action. Further, the automatically applied braking is operated with the automatically applied braking force after the correction when the measured value of the inter-vehicle distance from the preceding vehicle is equal to or less than the corrected automatic braking distance. In other words, the timing is advanced by the automatically applied braking distance after correction, and the slow braking is activated by the automatically applied braking force after correction. Enough time can be given. As a result, it is possible to avoid a collision with the preceding vehicle while avoiding a collision with the following vehicle.

  An embodiment of the present invention will be described based on the drawings.

  FIG. 1 is a schematic diagram showing a configuration of a vehicle travel control device, which includes a means 11 for measuring an inter-vehicle distance and a relative speed with a preceding vehicle, a means 12 for measuring an inter-vehicle distance and a relative speed with a succeeding vehicle, Is provided. As the means 11 for measuring the inter-vehicle distance and relative speed with the preceding vehicle and the means 12 for measuring the inter-vehicle distance and relative speed with the rear vehicle, a millimeter wave radar device is used. The inter-vehicle distance is calculated from the time to reach. Also, the amount of change in the inter-vehicle distance per unit time (difference between the previous measurement value and the current measurement value) is calculated as a relative speed.

  Reference numeral 10 denotes a control unit (collision damage reduction device) that controls the buzzer 16 in the driver's cab, the stop lamp 17 at the rear of the vehicle body, and the hazard lamp 18 as will be described later. The buzzer 16 in the driver's cab constitutes a means for warning the driver of the own vehicle of the relative relationship (approaching state) with the preceding vehicle. The stop lamp 17 and the hazard lamp 18 at the rear of the vehicle body are also used as means for alerting the driver of the following vehicle of the relative relationship (approaching state) between the host vehicle and the preceding vehicle. The relative speed with respect to the preceding vehicle and the relative speed with the following vehicle may be obtained from the measured value of the own vehicle speed (detected value of the vehicle speed sensor 19) and the measured value of the inter-vehicle distance.

  FIG. 2 is a flowchart for explaining the control contents of the collision damage alleviating unit 10.

  In S1, the measured value of the inter-vehicle distance and relative speed with the preceding vehicle, and the measured value of the inter-vehicle distance and relative speed with the following vehicle are read.

  In S2, the "distance to apply braking automatically" and the "braking force to apply automatically" at that time are set as the limit distances that can avoid a collision with the vehicle ahead by the driver's operation.

  In S3, the inter-vehicle distance and relative speed (measured value of S1) with the preceding vehicle, the inter-vehicle distance and relative speed (measured value of S1) with the following vehicle, and the "automatic braking distance" (S2 Calculate the risk of collision with the following vehicle when braking is applied according to the calculated value based on the calculated value) and the "automatic braking force" (the calculated value of S2).

  In S4, when the calculated value of the risk level is higher than the predetermined level, the “automatic braking distance” (the calculated value of S2) and “automatically” are set so that the risk level is below the predetermined level. Correct the "braking force to be applied" (the calculated value of S2).

  In S5, based on the “automatic braking distance after correction” (calculated value of S4), the distance that should generate an alarm for the driver of the vehicle and the alarm for the driver of the following vehicle Calculate the distance.

  In S6, it is determined whether or not the inter-vehicle distance (measured value of S1) of the preceding vehicle is equal to or less than the “distance for automatic braking after correction” (the calculated value of S4).

  In S7, the inter-vehicle distance of the vehicle ahead (measured value of S1) is the calculated value of S5 ("distance to generate an alarm for the driver of the own vehicle", "distance to generate an alarm for the driver of the following vehicle" ) Determine whether or not

  When the determination of S6 is yes, the process proceeds to S8, and braking is started in addition to the operation of the buzzer 16 (sounding), the operation of the stop lamp 17 and the hazard lamp 18 (lighting). When the determination of S6 is no and the determination of S7 is yes, the process proceeds to S9, and the buzzer 16, the stop lamp 17, and the hazard lamp 18 are operated. If the determination in S7 is no, return to S1.

  If the distance between the vehicles ahead (measured value of S1) is less than or equal to the “automatic braking distance after correction” (calculated value of S4) by S6 and S8, the “automatic braking force after correction” Means for applying a brake. When S7 and S9 cause the inter-vehicle distance (measured value of S1) to be less than the “distance to generate an alarm” (calculated value of S5) or less, an alarm for the driver of the own vehicle and an alarm for the driver of the following vehicle The means for generating is configured.

  Regarding S2 to S5, the contents of control (processing) will be described in more detail.

  In S2 (processing to set “automatic braking distance” and “automatic braking force”), the front-rear limit distance (braking avoidance limit distance) that can avoid collision with the preceding vehicle by braking = (Measured value of relative speed × Measured value of relative speed) / (2 × Maximum deceleration).

  In this embodiment, in addition to the braking avoidance limit distance, the limit distance in the front-rear direction (steering avoidance limit distance) that can avoid a collision with the preceding vehicle by steering = (time required for steering to avoid the collision) × relative speed, Is calculated from these calculated values (braking avoidance limit distance, steering avoidance limit distance) as a limit distance that can avoid a collision with the vehicle ahead by the driver's operation, and “automatic braking distance” = min [braking avoidance Limit distance, steering avoidance limit distance] are set (see FIG. 6).

  In this control system, “automatic braking force” is set as a constant “deceleration based on the maximum braking force that can be automatically applied.” The maximum deceleration can be generated by the driver's operation. It means the maximum value of deceleration.

  FIG. 4 illustrates braking avoidance limit distance = (measured value of relative speed × measured value of relative speed) / (2 × maximum deceleration). In FIG. 4, A is the own vehicle, and B is a preceding vehicle (front vehicle).

  When the relative relationship with the preceding vehicle B (front vehicle) is in the traveling state as shown in the figure, the time T required for the host vehicle A to decelerate to the same speed as the preceding vehicle B (front vehicle) by braking is V1−. From α1 · T = V2, T = (V1−V2) / α1.

Travel distance L1 of the vehicle A at time T, L1 = V1 · T-α1 · T 2/2 = (V1 2 -V2 2) / (2 · α1), and becomes. The traveling distance L2 of the preceding vehicle at time T is L2 = V2 · T = V2 · (V1−V2) / α1.

The limit distance L0 (braking avoidance limit distance) for not colliding with the preceding vehicle B is L0 = L1-L2 = (V1 ² −V2 ² ) / (2 · α1) −V2 · (V1−V2) / α1 = ( V1−V2) ² /(2.α1). Here, if V1−V2 = Vr (relative speed), L0 = Vr ² /(2.α1), and the braking avoidance limit distance L0 is (relative speed Vr × relative speed Vr) / (2 × α1). , Is calculated as α1 is the maximum deceleration of the vehicle.

  FIG. 5 illustrates the steering avoidance limit distance, and the steering avoidance limit distance L4 is L4 = (V1−V2) · TTC = Vr · TTC. TTC is the time required for steering to avoid a collision, and is set as a constant. Therefore, the steering avoidance limit distance L4 is calculated as (time required for steering to avoid a collision) × relative speed Vr. In FIG. 5, A is the own vehicle, and B is a preceding vehicle (front vehicle).

  FIG. 3 is a flowchart for explaining the control contents of S3 (processing for calculating the risk of collision with the following vehicle when braking is applied as calculated).

  In S3.1, the time until the vehicle collides with the preceding vehicle when the relative relationship with the current vehicle continues (predicted collision time) = (measured distance between the preceding vehicle) / (with the preceding vehicle) Relative speed measurement value) is calculated. In S3.2, the time until the brake is operated according to the set values ("automatic braking distance", "automatic braking force") when the relative relationship with the current vehicle continues. (Brake prediction time) = Collision prediction time − {“Automatic braking distance” (set value of S2) / (measured value of relative speed with the preceding vehicle)} is calculated.

  In S3.3, the relative relationship (inter-vehicle distance, relative speed) with the following vehicle at the time when the predicted braking time has elapsed is calculated. That is, the relative speed with the subsequent vehicle at the time when the predicted braking time has elapsed = the measured value of the relative speed with the subsequent vehicle, the inter-vehicle distance with the subsequent vehicle at the time when the predicted braking time has elapsed = the measured value of the inter-vehicle distance with the subsequent vehicle−the subsequent vehicle Measured value of relative speed x Calculated value of predicted braking time.

  In S3.4, the time (braking reaction time) until the driver of the following vehicle recognizes and judges the braking of the vehicle and takes the avoidance operation is set as a constant. Relative speed = "Relative speed with the following vehicle when the estimated braking time has elapsed" (calculated value of S3.3) + "Automatic braking force" (calculated value of S2) x Braking reaction time, predicted braking time Inter-vehicle distance with subsequent vehicle at elapsed time = “Inter-vehicle distance with subsequent vehicle at predicted braking time elapsed” (calculated value of S3.3) − “Inter-vehicle distance with subsequent vehicle at predicted braking time elapsed” (S3. (Calculated value of 3) × braking reaction time− “braking force to be applied automatically” (calculated value of S2) × braking reaction time × braking reaction time ÷ 2.

  In S3.5, as the risk of collision with the following vehicle, the time from when the braking reaction time elapses until the subsequent vehicle collides (predicted collision time with the subsequent vehicle after the braking reaction time has elapsed) = “predicted braking time” The distance between the following vehicle at the elapsed time (calculated value of S3.4) ÷ “the relative speed with the subsequent vehicle when the braking reaction time has elapsed” (calculated value of S3.4) is calculated.

  In S4 of FIG. 2 (processing for correcting “automatic braking distance” and “automatic braking force” based on the risk of collision with the following vehicle), the risk (calculation of S3.5) "Time required for driver's avoidance operation" (driver's normal avoidance time) is set as a constant as a predetermined level to be compared with (value)), and deviation = (calculated value of danger)-(driver's avoidance operation) Required time). Next, when the deviation> 0, a correction value of “automatic braking distance” and a correction value of “automatic braking force” corresponding to the deviation are obtained from a data map (not shown). "Automatic braking distance after correction" = "Automatic braking distance" (set value of S2) + correction value, "Automatic braking force after correction" = "Automatic braking force "(Set value of S2) + correction value.

  In S5, the “alarm operating time for warning of automatic braking” is set, “distance to generate warning for driver of own vehicle” and “distance to generate alarm for driver of following vehicle” "=" Distance for automatic braking after correction "+" Relative speed with the vehicle ahead "(measured value of S1) x (actuation time for warning for automatically applying braking) is calculated.

  In such a control system, the “distance to automatically apply braking” and the “automatic braking force” at that time are set as the limit distance that can avoid a collision with the vehicle ahead by the driver's operation, The risk of collision with the following vehicle is calculated when braking is applied according to the set values ("automatic braking distance", "automatic braking force"). When the calculated value of the risk level is higher than the predetermined level, the set values of “automatic braking distance” and “automatic braking force” are corrected so that the risk level is below the predetermined level. The In other words, when the calculated value of the risk level is higher than the predetermined level, the set value of “automatic braking distance” is increased and the set value of “automatic braking force” is corrected to be small. It is suppressed below a predetermined level.

  The “distance to generate an alarm” is calculated based on the “distance for automatic braking after correction”, and when the measured value of the inter-vehicle distance with the preceding vehicle is equal to or less than the “distance to generate an alarm” An alarm for the driver of the own vehicle and an alarm for the driver of the following vehicle are generated. For this reason, the driver | operator of a subsequent vehicle can be provided with the time allowance for the collision avoidance action. In addition, “automatic braking” operates with “automatic braking force after correction” when the measured value of the distance between the vehicle and the vehicle ahead is below the “automatic braking distance after correction”. To do. In other words, the timing is advanced by the “automatic braking distance after correction” and the slow braking is activated by the “automatic braking force after correction”. It is possible to provide sufficient time for avoiding the collision. As a result, it is possible to avoid a collision with the preceding vehicle while avoiding a collision with the following vehicle.

  In S2 of FIG. 2, the “distance for automatic braking” is selected as the smaller one of the braking avoidance limit distance and the steering avoidance limit distance. Therefore, it is set on the safe side. The “risk of collision with the following vehicle” includes the time (braking reaction time) until the driver of the following vehicle recognizes and judges the braking of the own vehicle and takes the avoidance operation according to the flowchart of FIG. It is precisely and accurately calculated as a predicted collision time with the following vehicle after the braking reaction time has elapsed. The predicted collision time with the following vehicle after the braking reaction time has elapsed is, in S4 in FIG. 2, when deviation> 0 based on deviation = (calculated value of danger) − (time required for driver avoidance operation). The correction value corresponding to the deviation is obtained from the map data, and “distance to automatically apply braking after correction =“ distance to apply braking automatically ”+ correction value,“ automatic braking force after correction ” “= Braking force to be applied automatically” + correction value, it is possible to accurately correct without exceeding the “time required for the driver's avoidance operation”. As a result, the reliability of the collision damage mitigation system can be greatly improved.

  For example, as shown in FIG. 7, the inter-vehicle distance with the preceding vehicle B is 100 m, the relative speed with the preceding vehicle B is 10 m / s faster, the inter-vehicle distance with the following vehicle C is 60 m, and the following vehicle C The control content of the control unit 10 will be specifically described with respect to the driving situation in which the relative speed of the following vehicle C is 5 m / s faster.

In the means (S2) for setting the “automatic braking distance” and the “automatic braking force” at that time, the time required for steering to avoid the collision: 0.8 s, the maximum deceleration: 6 m / s ^2. Automatic braking force: 5 m / s ² is set as a constant.

Steering avoidance limit distance = [Time required for steering to avoid a collision: 0.8 s] × [Measured value of relative speed with the preceding vehicle: 10 m / s] = 8 m, Braking avoidance limit distance = [Relative speed with the preceding vehicle Measured value: 10 m / s] ² / (2 × maximum deceleration: 6 m / s ² ) = 8.3 m. “Automatic braking distance” = min [braking avoidance limit distance: 8.3 m, steering avoidance limit distance: 8 m] = 8 m is set.

  In the means (S3) for calculating the risk of collision with the following vehicle C when braking is applied according to the calculated value, the predicted collision time with the preceding vehicle B = [distance between the preceding vehicle B: 100 m] / [Relative speed with the forward vehicle B: 10 m / s] = 10 s, Predicted braking time for the forward vehicle B = [Predicted collision time: 10 s] − ([Automatic braking distance: 8 m] / [Front vehicle B Relative speed: 10 m / s] = 9.2 s.

  Relative speed with the following vehicle at the elapsed time of [Brake predicted time: 9.2s] = [Relative speed with the subsequent vehicle C: 5m / s] = 5m / s, Subsequent at the elapsed time of [Predicted braking time: 9.2s] Distance between vehicle C = [Distance between following vehicle C: 60 m] − [Relative speed with following vehicle C: 5 m / s] × [Predicted braking time: 9.2 s] = 14 m.

[Braking reaction time: 0.8 s] is set as a constant, and the relative speed with the following vehicle C at the time when [braking reaction time: 0.8 s] has elapsed = [the relative speed with the following vehicle C at the time when the estimated braking time has elapsed: 5 m / s] + [Automatic braking force: 5 m / s ² ] × [Brake reaction time: 0.8 s] = 9.0 m / s, [Brake reaction time: 0.8 s] Inter-vehicle distance with the following vehicle = [Distance between the following vehicle C when the predicted braking time has elapsed: 14 m]-[Relative speed with the subsequent vehicle C when the predicted braking time has elapsed: 5 m / s] x [Brake reaction time: 0.8 s]-[Auto Braking force to be applied: 5 m / s ² ] × [braking reaction time: 0.8 s] ² ÷ 2 = 8.4 m.

  The degree of risk of collision with the following vehicle when braking is applied according to the calculated value is the time from when the braking reaction time elapses until the following vehicle C collides (collision prediction with the following vehicle C after the braking reaction time has elapsed). Time) = [Distance between the following vehicle C when the predicted braking time has elapsed: 8.4 m] / [Relative speed with the subsequent vehicle C when the braking reaction time has elapsed: 9.0 m / s] = 0.93 s.

In the means (S4) for correcting the “automatic braking distance” and the “automatic braking force” based on the “risk of collision with the following vehicle C”, [the normal avoidance time of the driver: 1.6s] is set, and the [predicted collision time with the following vehicle C after the lapse of the braking reaction time: 0.93 s] is [driver's normal avoidance time: 1.6 s] or more (the risk of collision with the following vehicle C is higher). The “automatic braking distance: 8 m” and “automatic braking force: 5 m / s ² ” are corrected so as to be equal to or lower than a predetermined level. Deviation = [time required for driver's avoidance operation: 1.6 s] − [risk degree calculation value: 0.93 s] is calculated, and when deviation> 0, the deviation is calculated by searching a map (not shown). Find the corresponding correction value. In this example, [correction value: 5.5 m] for [automatic braking distance: 8 m], [correction value: 2.04 m / s ² ] for [automatic braking force: 5 m / s ² ], Is given as follows: “Automatic braking distance after correction” = [Automatic braking distance: 8 m] + [Correction value: 5.5 m] = 13.5 m, “Automatic braking force after correction” ”= [Automatic braking force: 5 m / s ² ] − [Correction value: 2.04 m / s ² ] = 2.96 m / s ² is calculated.

  In the means (S5) for calculating “distance to generate an alarm for the driver of the own vehicle A” and “distance to generate an alarm for the driver of the following vehicle C” (S5) Is set to "Distance to generate an alarm for the driver of the own vehicle A" and "Distance to generate an alarm for the driver of the following vehicle C" = [After correction] Automatically applied braking distance: 13.5m] + [relative speed with forward vehicle B: 10m / s] x [alarm time for warning to automatically apply braking: 0.8s] = 21.5m .

  In the means (S7, S9) for generating an alarm for the driver of the own vehicle A and an alarm for the driver of the following car C, the measured value of the inter-vehicle distance with the preceding vehicle B is [distance to generate an alarm: 21.5 m [Distance to generate alarm: 21.5 m] ≧ When the distance between the vehicle ahead B and the distance between the vehicle B and the front vehicle B, the “alarm for the driver of the own vehicle A” and “alarm for the driver of the following vehicle C” are activated To do.

When the inter-vehicle distance of the forward vehicle B is equal to or less than the “automatic braking distance after correction”, the vehicle (B6, S8) applies braking with the “automatic braking force after correction” during The measured value of the inter-vehicle distance with B is compared with [Automatic braking distance after correction: 13.5m], and [Automatic braking distance after correction: 13.5m] ≧ When the distance is reached, the braking operation is performed with the “automatic braking force applied after correction: 2.96 m / s ² ” together with the operation of “alarm for driver of own vehicle A” and “alarm for driver of following vehicle C”. It is.

  In this example, “distance to generate an alarm for the driver of the own vehicle A” and “distance to generate an alarm for the driver of the following vehicle C” = [distance for automatic braking after correction; 13.5 m] + [Relative speed with the car ahead: 10m / s] × [Operation time of warning for notifying braking automatically applied: 0.8s] = 21.5m, but warning of the driver of the vehicle A It is also conceivable that the generation timing and the alarm generation timing for the driver of the following vehicle C are not simultaneously set, and a time lag is set.

It is a schematic diagram of the control system which concerns on embodiment of this invention. It is a flowchart explaining the content of control similarly. It is a flowchart explaining the content of control similarly. It is explanatory drawing of a braking avoidance limit distance similarly. It is explanatory drawing of a steering avoidance limit distance similarly. It is a characteristic view of the distance which applies braking similarly. It is a driving | running | working condition figure explaining a control content similarly.

Explanation of symbols

10 Control unit (collision damage reduction device)
11, 12 Millimeter wave radar device 15 Brake device 16 Buzzer 17 Stop lamp 18 Hazard lamp

Claims (7)

Means for measuring the inter-vehicle distance and relative speed with the preceding vehicle, means for measuring the inter-vehicle distance and relative speed with the rear vehicle,
Means for automatically setting a braking distance and a braking force to be automatically applied as a limit distance by which a collision with a preceding vehicle can be avoided by a driver's operation;
Measure the distance between the vehicle ahead and the relative speed of the vehicle ahead, the distance between the vehicle behind it and the relative speed, the distance to automatically apply the braking, and the setting value of the braking force to apply automatically. Means for calculating the risk of collision with the following vehicle when applied according to the set value;
Means for correcting the automatically applied braking distance and the set value of the automatically applied braking force so that the calculated risk value is higher than a predetermined level, the risk level being equal to or lower than the predetermined level;
Means for calculating a distance at which an alarm for the driver of the following vehicle should be generated based on the automatically braked distance after correction;
Means for generating an alarm for the driver of the following vehicle when the measured value of the inter-vehicle distance with the preceding vehicle is less than the distance to generate the alarm;
Means for braking with the braking force automatically applied after correction when the measured value of the inter-vehicle distance of the vehicle ahead is equal to or less than the automatically applied braking distance after correction,
A travel control device for a vehicle, comprising: The means for calculating the risk of collision with the following vehicle is as follows:
Means for calculating a predicted braking time until braking is applied at a set distance when a relative relationship with the current forward vehicle continues;
Means for calculating the inter-vehicle distance of the succeeding vehicle at the time when the predicted braking time has elapsed from the calculated value of the predicted braking time and the inter-vehicle distance and relative speed of the subsequent vehicle;
Means for setting the braking reaction time until the driver of the following vehicle recognizes the braking of the own vehicle and takes the avoidance operation;
The distance traveled by the following vehicle during the braking reaction time, the distance shortened by the braking automatically applied to the following vehicle during the braking reaction time, and the deceleration by the braking automatically applied during the braking reaction time. Means for computing,
The braking reaction time from the distance between the following vehicles at the time of the predicted braking time, the distance traveled by the following vehicle during the braking reaction time, and the distance that the distance between the following vehicles automatically reduces during the braking reaction time. Means for calculating the inter-vehicle distance with the following vehicle at the time of passage,
Means for calculating the relative speed with the subsequent vehicle at the time when the braking reaction time elapses from the relative speed with the subsequent vehicle at the time when the braking prediction has elapsed and the deceleration due to braking automatically applied during the braking reaction time;
Means for calculating a predicted collision time from the time when the braking reaction time elapses, the relative speed at the time when the braking reaction time elapses, and the risk of a collision with the following vehicle until the collision with the following vehicle after the braking reaction time elapses ,
The vehicle travel control apparatus according to claim 1, comprising: The means for correcting the automatically applied braking distance and the automatically applied braking force set value are:
Means for setting the time required for the driver's avoidance operation as a predetermined level to be compared with the calculated risk level;
The deviation between the time required for the driver's avoidance operation and the risk of collision with the following vehicle is obtained. If deviation> 0, the correction value of the distance to be automatically braked corresponding to the deviation and the automatic multiplication are applied. Means for obtaining a correction value of power, and correcting to a set value + correction value for automatically applying braking, and a setting value-correction value for automatically applying braking force;
The vehicle travel control apparatus according to claim 1 or 2, further comprising: The means for setting the automatic braking distance and the automatic braking force at that time,
The braking avoidance limit distance as the limit distance in the front-rear direction that can avoid a collision with the preceding vehicle by braking is calculated from the maximum deceleration that the vehicle can issue by the driver's operation and the measured value of the relative speed of the preceding vehicle means,
Means for calculating a steering avoidance limit distance as a limit distance in the front-rear direction in which a collision with a preceding vehicle can be avoided by steering from a time required for steering to avoid the collision and a measured value of a relative speed with the preceding vehicle;
Based on these calculated values, the smaller one of the braking avoidance limit distance and the steering avoidance limit distance is set as the distance at which braking is automatically applied as the limit distance that can avoid a collision with the vehicle ahead by the driver's operation. means,
The vehicle travel control apparatus according to any one of claims 1 to 3, further comprising: The means for calculating the distance to generate the alarm is:
Means for setting an alarm activation time to automatically notify braking
Means for calculating the distance at which an alarm for the driver of the following vehicle should be generated from the operation time of this alarm, the automatically applied braking distance after correction, and the measured value of the relative speed with the preceding vehicle,
The vehicle travel control apparatus according to any one of claims 1 to 4, further comprising: Means for calculating a distance at which an alarm for the driver of the own vehicle should be generated based on the automatically braking distance after the correction;
Means for generating an alarm for the driver of the vehicle when the measured value of the distance between the vehicle and the vehicle ahead is less than the distance to generate the alarm;
The vehicle travel control apparatus according to any one of claims 1 to 4, further comprising: The means for calculating the distance to generate the alarm is:
Means for setting an alarm activation time to automatically notify braking
Means for calculating the distance at which an alarm for the driver of the own vehicle should be generated from the operation time of this alarm, the automatically applied braking distance after correction, and the measured value of the relative speed with the preceding vehicle,
The vehicle travel control apparatus according to claim 6.