Inter-vehicle distance control device, inter-vehicle distance control method, and non-transitory storage medium having program stored therein

Abstract

The invention provides an inter-vehicle distance control device, an inter-vehicle distance control method, and a non-transitory storage medium storing a program thereof. A driving assistance control ECU (10) controls a host vehicle such that the inter-vehicle distance (host-vehicle inter-vehicle distance) between a preceding vehicle located directly in front of the host vehicle and the host vehicle is maintained at a predetermined target inter-vehicle distance. A driving assistance ECU is provided. The inter-vehicle distance acquisition unit acquires (1) the inter-vehicle distance between a first other vehicle stopped in the periphery of the host vehicle and a second other vehicle stopped in front of the first other vehicle, and / or (2) the inter-vehicle distance between the first other vehicle stopped in the periphery (rear) of the host vehicle and the host vehicle stopped in front of the first other vehicle as the inter-vehicle distance when the host vehicle is stopped. A stop-time preferred inter-vehicle distance, which is set on the basis of the acquired inter-vehicle distance at the time of stop, is used as "the target inter-vehicle distance when the host vehicle has stopped".

Description

TECHNICAL FIELD

[0001] The present application relates to a vehicle-to-vehicle distance control device, a vehicle-to-vehicle distance control method, and a non-transitory storage medium storing a program thereof, which control a vehicle-to-vehicle distance of a host vehicle as a distance between a preceding vehicle located in front of the host vehicle and the host vehicle. BACKGROUND

[0002] In the past, there has been known a device that performs vehicle-to-vehicle distance control for maintaining a vehicle-to-vehicle distance (hereinafter, sometimes referred to as "host vehicle-to-vehicle distance") between a preceding vehicle traveling in front of a host vehicle and the host vehicle at a predetermined target vehicle-to-vehicle distance. One of such devices (hereinafter, referred to as "conventional device") acquires a vehicle-to-vehicle distance (hereinafter, sometimes referred to as "other vehicle-to-vehicle distance") between another vehicle existing in the vicinity of the host vehicle and "another other vehicle or the host vehicle" located in front of the other vehicle. Further, the conventional device changes the target vehicle-to-vehicle distance corresponding to the host vehicle speed at the point of time when the other vehicle-to-vehicle distance is acquired, according to the acquired other vehicle-to-vehicle distance (for example, refer to Patent Literature 1).

[0003] PRIOR ART DOCUMENTS

[0004] PATENT LITERATURE

[0005] Patent Literature 1: Japanese Patent Application Laid-Open No. 2008-189055 SUMMARY

[0006] However, the above-described conventional device can set the target vehicle-to-vehicle distance in a case where the host vehicle is in a stopped state (i.e., the host vehicle speed is "0") based on the other vehicle-to-vehicle distance of the other vehicle (i.e., the other vehicle speed is not "0") traveling and the other vehicle traveling in front of the other vehicle. Therefore, according to the above-described conventional device, there is a problem that the host vehicle-to-vehicle distance when the host vehicle is stopped can greatly deviate from an appropriate value with high probability.

[0007] The present application has been made to solve the above-described problems. That is, one of the objects of the present application is to provide a vehicle-to-vehicle distance control device, a vehicle-to-vehicle distance control method, and a program thereof, which can set the host vehicle-to-vehicle distance in a case where the host vehicle is in a stopped state to a more appropriate distance.

[0008] One of the technical solutions of the vehicle-to-vehicle distance control device according to the present application comprises:

[0009] an information acquisition device (21, 22, 23L, 23R, 24L, 24R, 25, 26, 27L, 27R, 28L, and 28R) that acquires information about an object existing in the vicinity of the host vehicle; and

[0010] The controller (10, 40, and 50) is capable of performing inter-vehicle distance control that acquires, based on the information, an own-vehicle inter-vehicle distance that is an inter-vehicle distance between a preceding vehicle located directly in front of the own vehicle and the own vehicle (step 570), and controls the own vehicle in such a manner that the acquired own-vehicle inter-vehicle distance is maintained at a predetermined target inter-vehicle distance (steps 580 and 590).

[0011] Further, the controller is configured to,

[0012] acquire, based on the information, an inter-vehicle distance between a first other vehicle stopped in the vicinity of the own vehicle and a second other vehicle stopped directly in front of the first other vehicle or the own vehicle stopped directly in front of the first other vehicle as a stopped-time other-vehicle inter-vehicle distance (step 950),

[0013] use a stopped-time preferred inter-vehicle distance set in accordance with the acquired stopped-time other-vehicle inter-vehicle distance as the target inter-vehicle distance in a case where the own vehicle is stopped (steps 970 and 720).

[0014] According to this technical solution, based on the "information about an object existing in the vicinity of the own vehicle" from the information acquisition device

[0015] • an inter-vehicle distance between a first other vehicle stopped in the vicinity of the own vehicle and a second other vehicle stopped directly in front of the first other vehicle (refer to D12 to D15 of Figure 4 ) and

[0016] • an inter-vehicle distance between a first other vehicle stopped in the vicinity of the own vehicle and the own vehicle stopped directly in front of the first other vehicle (refer to D11 of Figure 4 )

[0017] as a stopped-time other-vehicle inter-vehicle distance.

[0018] Therefore, in a case where at least one of the first other vehicle and the second other vehicle is not stopped, the inter-vehicle distance therebetween is not acquired as a stopped-time other-vehicle inter-vehicle distance. Similarly, in a case where at least one of the first other vehicle and the own vehicle is not stopped, the inter-vehicle distance therebetween is not acquired as a stopped-time other-vehicle inter-vehicle distance.

[0019] Further, the stopped-time preferred inter-vehicle distance used as the target inter-vehicle distance when the own vehicle is stopped is set in accordance with the acquired stopped-time other-vehicle inter-vehicle distance. Therefore, it is possible to control the target inter-vehicle distance when the own vehicle is stopped to a preferred distance.

[0020] In addition, a vehicle-to-vehicle distance ensured between the passenger vehicle and a preceding vehicle when the passenger vehicle is stopped is not the same as a vehicle-to-vehicle distance ensured between a vehicle other than the passenger vehicle (for example, a truck) and a preceding vehicle when the vehicle other than the passenger vehicle is stopped.

[0021] Therefore, in one aspect of the vehicle-to-vehicle distance control device described above,

[0022] The controller is configured to

[0023] determine whether the first other vehicle is a predetermined vehicle type based on the information (step 960), and in a case where it is determined that the first other vehicle is the predetermined vehicle type, not reflect a vehicle-to-vehicle distance between the first other vehicle determined to be the predetermined vehicle type and a second other vehicle stopped immediately in front of the first other vehicle, and a vehicle-to-vehicle distance between the first other vehicle determined to be the predetermined vehicle type and the host vehicle stopped immediately in front of the first other vehicle, on the stop-time preferred vehicle-to-vehicle distance (step 970).

[0024] According to this aspect, the other-vehicle-to-vehicle distance when the first other vehicle that is the predetermined vehicle type is stopped, which is not suitable as a vehicle-to-vehicle distance when the host vehicle is stopped, is not reflected on the stop-time preferred vehicle-to-vehicle distance. As a result, the host vehicle-to-vehicle distance when the host vehicle is stopped can be controlled to a more appropriate distance.

[0025] In one aspect of the vehicle-to-vehicle distance control device described above,

[0026] The controller is configured to

[0027] return the stop-time preferred vehicle-to-vehicle distance to an initial value when the vehicle speed of the host vehicle, i.e., the host vehicle speed, is higher than a predetermined congestion travel determination vehicle speed (step 710: No, step 730)

[0028] After that, in a case where the stop-time preferred vehicle-to-vehicle distance is set again from a time point when the host vehicle has stopped after deceleration by the vehicle-to-vehicle distance control to a time point when a predetermined waiting period has elapsed (step 1040: Yes, step 1050, step 970, step 980), the host vehicle is caused to advance in a manner such that the host vehicle-to-vehicle distance coincides with the stop-time preferred vehicle-to-vehicle distance set again (step 1070, step 1080).

[0029] According to the technology, in a case where the host vehicle stops in a certain congested environment, temporarily escapes from the congestion, and travels thereafter (when the host vehicle speed is higher than a predetermined congestion travel determination vehicle speed), the stop-time preferred inter-vehicle distance is returned to the initial value. Also, in a case where the host vehicle stops again in another congested environment, the host vehicle is caused to advance in such a manner that the stop-time inter-vehicle distance ensured by the host vehicle becomes a stop-time preferred inter-vehicle distance newly set in accordance with a stop-time inter-vehicle distance ensured by another vehicle in the other congested environment. Thus, the stop-time inter-vehicle distance ensured by the host vehicle can be controlled to be an appropriate inter-vehicle distance corresponding to the congested environment which changes with the situation.

[0030] In one aspect of the inter-vehicle distance control device described above,

[0031] The controller is configured to,

[0032] when the vehicle speed of the host vehicle, i.e., the host vehicle speed, changes from a speed higher than a predetermined congestion travel determination vehicle speed to a speed equal to or lower than the congestion travel determination vehicle speed during execution of the inter-vehicle distance control, acquire, based on the information, an inter-vehicle distance between a third other vehicle traveling in the vicinity of the host vehicle and a fourth other vehicle traveling immediately in front of the third other vehicle or the host vehicle traveling immediately in front of the third other vehicle as an other-vehicle inter-vehicle distance in congestion travel (step 850),

[0033] store the host vehicle speed at the point in time at which the other-vehicle inter-vehicle distance in congestion travel is acquired as a learning vehicle speed (step 880, look-up table M1 of step 720),

[0034] calculate a preferred inter-vehicle distance in congestion travel based on the acquired other-vehicle inter-vehicle distance in congestion travel (step 870),

[0035] store the preferred inter-vehicle distance in congestion travel in association with the learning vehicle speed (look-up table M1 of step 720),

[0036] in a case where the host vehicle speed is lower than the learning vehicle speed, determine the target inter-vehicle distance based on the stop-time preferred inter-vehicle distance, the preferred inter-vehicle distance in congestion travel, the learning vehicle speed, and the host vehicle speed (step 720).

[0037] According to the technology, the target inter-vehicle distance in a case where the host vehicle speed is in a range from zero to the learning vehicle speed can be set to an appropriate value corresponding to an inter-vehicle distance ensured by another vehicle in the vicinity of the host vehicle. Also, since the target inter-vehicle distance can be caused not to change greatly immediately before the host vehicle stops and immediately after the host vehicle stops, the host vehicle can be caused to stop while smoothly decelerating.

[0038] In the above description, in order to help understanding of the present application, names and / or reference numerals used in the embodiments described later are added in parentheses to the configuration of the application corresponding to the embodiments. However, the respective elements of the present application are not limited to the embodiments defined by the names and / or reference numerals. The present application also relates to a vehicle distance control method and a non-transitory storage medium storing a program thereof. BRIEF DESCRIPTION OF DRAWINGS

[0039] Figure 1 is a diagram showing the general configuration of a vehicle distance control device to which the embodiments of the present application relate.

[0040] Figure 2 is a diagram showing the photographing ranges of the plurality of cameras shown in Figure 1 .

[0041] Figure 3 is a diagram showing the vehicle distance of the other vehicle that is running.

[0042] Figure 4 is a diagram showing the vehicle distance of the other vehicle that is stopped.

[0043] Figure 5 is Figure 1 a routine executed by the CPU of the drive assist ECU shown in .

[0044] Figure 6 is Figure 1 a subroutine executed by the CPU of the drive assist ECU shown in .

[0045] Figure 7 is Figure 1 a subroutine executed by the CPU of the drive assist ECU shown in .

[0046] Figure 8 is Figure 1 a routine executed by the CPU of the drive assist ECU shown in .

[0047] Figure 9 is Figure 1 a routine executed by the CPU of the drive assist ECU shown in .

[0048] Figure 10 is Figure 1 a routine executed by the CPU of the drive assist ECU shown in .

[0049] Figure 11 is Figure 1 a routine executed by the CPU of the drive assist ECU shown in .

[0050] REFERENCE NUMERAL DESCRIPTION

[0051] 10: Driver assistance ECU; 40: Powertrain ECU; 50: Brake ECU. Detailed Implementation

[0052] Hereinafter, the workshop distance control device (hereinafter referred to as "this control device") according to the embodiments of the present invention will be described with reference to the accompanying drawings.

[0053] (constitute)

[0054] Figure 1 The control device DS shown is mounted on this vehicle. This vehicle can be any of the following: a vehicle powered by an internal combustion engine, a vehicle powered by an electric motor (i.e., an electric vehicle), or a hybrid vehicle. That is, the power source of this vehicle is not particularly limited. In this example, this vehicle is a car primarily intended for human transportation with a seating capacity of, for example, 10 people or less (i.e., a passenger car). However, this control device DS can also be applied to vehicles other than passenger cars.

[0055] This control unit DS includes a driver assistance ECU 10, a powertrain ECU 40, and a brake ECU 50. The driver assistance ECU 10 is sometimes referred to as the "DSECU". These ECUs are connected via a communication and sensor system CAN (Controller Area Network) to exchange data. ECU is short for Electronic Control Unit, also known as a controller or computer. An ECU is an electronic control circuit with a microcomputer as its main component. The microcomputer includes a CPU (processor), ROM, RAM, non-volatile memory capable of writing data, and interfaces. The CPU executes instructions (routes) stored in the memory (ROM) to achieve the various functions described later.

[0056] This control unit DS is equipped with multiple camera devices and multiple radar devices. Each of the multiple camera devices and each of the multiple radar devices is connected to the DSECU via CAN in a manner that enables data exchange with the DSECU.

[0057] The multiple camera devices include a frontal remote camera device 21, a front camera device 22, a left front side camera device 23L, a right front side camera device 23R, a left rear side camera device 24L, a right rear side camera device 24R, and a rear camera device 25.

[0058] The forward-facing distant camera device 21 includes a camera with a lens having a predetermined first horizontal viewing angle, which measures a range from the vehicle to a first distance in front of the vehicle (refer to...). Figure 2The scene of A21 was photographed to obtain image data of the distant area in front.

[0059] The front camera device 22, the left front side camera device 23L, the right front side camera device 23R, the left rear side camera device 24L, the right rear side camera device 24R, and the rear camera device 25 each include a camera with a wide-angle lens or an ultra-wide-angle lens, and capture the scene within a range that is larger than the first horizontal field of view.

[0060] The front camera device 22 measures the range up to a "second distance shorter than the first distance" from the vehicle to the front of the vehicle (refer to...). Figure 2 The scene of A22 was photographed to obtain wide-angle image data of the front.

[0061] The left front side camera device 23L covers the area extending from the second distance to the left front of the vehicle (refer to...). Figure 2 The scene of the A23L was captured to obtain wide-angle image data from the left front.

[0062] The right front side camera device 23R covers the area extending from the vehicle to the second distance to the right front of the vehicle (refer to...). Figure 2 The scene was captured by the A23R camera to obtain wide-angle image data from the right front.

[0063] The left rear-side camera device 24L covers the area extending from the second distance to the left rear of the vehicle (refer to...). Figure 2 The scene was captured by the A24L to obtain wide-angle image data from the left rear.

[0064] The right rear-side camera device 24R covers the area extending from the second distance to the right rear of the vehicle (refer to...). Figure 2 The scene was captured by the A24R camera to obtain wide-angle image data from the right rear.

[0065] The rear camera device 25 covers a range extending from the second distance from the vehicle to the rear of the vehicle (refer to...). Figure 2 The scene was captured using the A25 camera to obtain wide-angle image data of the rear.

[0066] like Figure 1As shown, the range of the scenes captured by each of these camera devices overlaps between adjacent camera devices. Each of these camera devices sends the acquired image data to the DSECU every predetermined time interval. The DSECU integrates (synthesizes) the image data acquired by the aforementioned multiple camera devices, including the forward-facing distant camera device 21. Therefore, the DSECU is able to acquire image data of objects located around the vehicle (within a 360-degree range centered on the vehicle) and the road surface around the vehicle every predetermined time interval.

[0067] The DSECU identifies (detects) the left and right boundary lines of its own lane, the left and right boundary lines of the adjacent lane to its left, and the right and right boundary lines of the adjacent lane to its right, based on the acquired image data. Furthermore, lane boundaries are typically lane markings, such as white and yellow lines. The DSECU also generates camera object information based on the acquired image data. This camera object information includes information such as the "position (longitudinal and lateral position) and category" of objects present around the vehicle. The object category includes the vehicle type of other vehicles (e.g., passenger cars, trucks, buses, and two-wheeled motor vehicles).

[0068] like Figure 3 As shown, the multiple radar devices include a front radar device 26, a left front side radar device 27L, a right front side radar device 27R, a left rear side radar device 28L, and a right rear side radar device 28R.

[0069] Multiple radar devices are known means of acquiring information about objects present in the vicinity of the vehicle using millimeter-wave radio waves. In short, each radar device acquires information about objects present in its respective detection range (i.e., radar information) based on information about the transmitted and received millimeter waves by transmitting millimeter waves into a predetermined detection range and receiving millimeter waves reflected by objects.

[0070] The forward radar device 26 acquires radar information about objects present in front of the vehicle within a predetermined detection range.

[0071] The left front side radar device 27L acquires radar information about objects present on the left front side of the vehicle within a predetermined detection range.

[0072] The right front side radar device 27R acquires radar information about objects present on the right front side of the vehicle within a predetermined detection range.

[0073] The left rear side radar device 28L acquires radar information about objects present on the left rear side of the vehicle within a predetermined detection range.

[0074] The right rear side radar device 28R acquires radar information about an object existing in a predetermined detection range on the right rear side of the host vehicle.

[0075] Each of these radar devices transmits the acquired radar information to the DSECU every predetermined time. The DSECU acquires radar object information based on the radar information acquired by the plurality of radar devices. The radar object information includes the distance of an object from the position at which each radar device is disposed, the azimuth of the object with respect to the position at which each radar device is disposed, and the relative speed of the object with respect to each radar device, and the like. Further, the detection range of the left rear side radar device 28L and the detection range of the right rear side radar device 28R overlap in the rear of the host vehicle.

[0076] The DSECU integrates (synthesizes) the radar object information generated based on the radar information acquired by the plurality of radar devices, and generates radar integrated object information about an object existing in the surroundings of the host vehicle (a range other than the vicinity of the front lateral direction of the host vehicle). The radar integrated object information includes the "azimuth of the object and the relative speed of the object with respect to the host vehicle", and the like.

[0077] The DSECU integrates the camera object information and the radar integrated object information, and generates fusion object information as the final object information about an object existing in the surroundings of the host vehicle.

[0078] Further, the DSECU is connected to the ACC operation switch 31, the vehicle speed sensor 32, and the accelerator pedal operation amount sensor 33, and receives their output signals.

[0079] The ACC operation switch 31 is a switch operated by the driver of the host vehicle. ACC means adaptive cruise control. ACC includes follow-up vehicle distance control (sometimes referred to simply as "vehicle distance control") and constant speed travel control.

[0080] When a predetermined operation of the ACC operation switch 31 is performed by the driver, the DSECU determines that a request such as an ACC start request, an ACC end request, and an ACC restart request is generated in accordance with the operation. Further, when another predetermined operation of the ACC operation switch 31 is performed, the DSECU changes the target vehicle distance time Ttgt. The target vehicle distance time Ttgt is selected from a first time T1 corresponding to a long target vehicle distance, a second time T2 corresponding to an intermediate target vehicle distance, and a third time T3 corresponding to a short target vehicle distance.

[0081] The vehicle speed sensor 32 detects the speed of the vehicle (vehicle speed) Vh and outputs a signal representing the vehicle speed Vh.

[0082] The accelerator pedal operation amount sensor 33 detects the operation amount (accelerator pedal operation amount AP) of the accelerator pedal of the vehicle (not shown) and outputs a signal representing the accelerator pedal operation amount AP.

[0083] The powertrain ECU 40 is connected to the powertrain sensor 41 and the powertrain actuator 42. The powertrain ECU 40 receives detection signals from the powertrain sensor 41. In the case of an internal combustion engine as the drive source, the powertrain sensor 41 includes a intake air volume sensor and an engine speed sensor, etc. The powertrain ECU 40 controls the drive unit, including a power source of the vehicle (not shown), by driving the powertrain actuator 42, thereby adjusting the driving force of the vehicle and controlling its acceleration.

[0084] The brake ECU 50 is connected to the brake sensor 51 and the brake actuator 52. The brake ECU 50 receives detection signals from the brake sensor 51. The brake sensor 51 includes a brake pedal operation sensor and a wheel speed sensor that detects the wheel speed of each wheel. The brake ECU 50 controls the braking device of the vehicle (not shown) by driving the brake actuator 52, thereby adjusting the braking force applied to the vehicle and thus controlling the acceleration (deceleration) of the vehicle.

[0085] (Job Summary)

[0086] like Figure 3 As shown, when the ACC execution condition is met, the control device DS performs the following vehicle-to-vehicle distance control (following vehicle-to-vehicle distance control): the vehicle HV follows the leading vehicle PV so that the actual vehicle-to-vehicle distance (i.e., the vehicle-to-vehicle distance) Dact between the vehicle HV and the preceding vehicle PV located directly in front of the vehicle HV is maintained at a predetermined target vehicle-to-vehicle distance Dtgt.

[0087] During normal driving (without driving in congested conditions), the target inter-vehicle distance Dtgt is set as the product of the vehicle speed Vh and the target inter-vehicle time Ttgt set by the driver of the vehicle HV (Vh·Ttgt).

[0088] During the period when the vehicle HV is in a congested environment and has not stopped (i.e., when the vehicle speed Vh is below the congested driving judgment speed VJth and greater than the positive extremely low speed judgment value VLth), the control device DS obtains the following "inter-vehicle distance D1 to inter-vehicle distance D5" based on "camera object information or fused object information" (refer to...). Figure 3) as the inter-vehicle distance of other vehicles during congested travel. Further, the "speed equivalent to the host vehicle speed Vh" is a speed of V1th or more obtained by subtracting a positive first predetermined speed dV1 from the host vehicle speed Vh, and V2th or less obtained by adding a positive second predetermined speed dV2 to the host vehicle Vh (host vehicle speed Vh).

[0089] Inter-vehicle distance D1 : the inter-vehicle distance of a rear vehicle Cl (a third other vehicle) that is located immediately behind the host vehicle HV on the host lane, is a speed equivalent to the host vehicle speed Vh, and is traveling (i.e., the speed ratio is greater than "0").

[0090] Inter-vehicle distance D2: the inter-vehicle distance of an other vehicle C3 (a third other vehicle) that is traveling in the same direction as the host vehicle HV on the left adjacent lane, is a speed equivalent to the host vehicle speed Vh, and is traveling (i.e., the speed ratio is greater than "0"), and an other vehicle C2 (a fourth other vehicle) that is traveling immediately in front of the other vehicle C3.

[0091] Inter-vehicle distance D3: the inter-vehicle distance of an other vehicle C4 (a third other vehicle) that is traveling in the same direction as the host vehicle HV on the left adjacent lane, is a speed equivalent to the host vehicle speed Vh, and is traveling (i.e., the speed ratio is greater than "0"), and an other vehicle C3 (a fourth other vehicle) that is traveling immediately in front of the other vehicle C4.

[0092] Inter-vehicle distance D4: the inter-vehicle distance of an other vehicle C6 (a third other vehicle) that is traveling in the same direction as the host vehicle HV on the right adjacent lane, is a speed equivalent to the host vehicle speed Vh, and is traveling (i.e., the speed ratio is greater than "0"), and an other vehicle C5 (a fourth other vehicle) that is traveling immediately in front of the other vehicle C6.

[0093] Inter-vehicle distance D5: the inter-vehicle distance of an other vehicle C7 (a third other vehicle) that is traveling in the same direction as the host vehicle HV on the right adjacent lane, is a speed equivalent to the host vehicle speed Vh, and is traveling (i.e., the speed ratio is greater than "0"), and an other vehicle C6 (a fourth other vehicle) that is traveling immediately in front of the other vehicle C7.

[0094] Further, among these inter-vehicle distances, in the case where the other vehicle is a vehicle of a predetermined vehicle type different from the vehicle type and class of the host vehicle HV (in this example, a passenger car), a large vehicle such as a truck or a bus, and either of a two-wheeled motor vehicle, the control device DS considers that the inter-vehicle distance ensured by the other vehicle is not an effective "inter-vehicle distance of other vehicles during congested travel". For example, in the case where the other vehicle is a large vehicle such as a truck or a bus, the control device DS considers that the inter-vehicle distance ensured by the other vehicle is not an effective "inter-vehicle distance of other vehicles during congested travel". Figure 4In the above-described example shown, if the other vehicle C3 is a truck, the control device DS considers that the inter-vehicle distance D2 is not an effective "inter-vehicle distance of other vehicle in congested travel (during congested travel)".

[0095] The control device DS calculates the inter-vehicle distance Dm in congested travel based on the effective "inter-vehicle distance of other vehicle in congested travel" in a case where one or more (preferably two or more) effective "inter-vehicle distance of other vehicle in congested travel" is obtained. For example, the control device DS calculates an average value of the effective "inter-vehicle distance of other vehicle in congested travel" as the inter-vehicle distance Dm in congested travel. Also, the control device DS stores (learns) the inter-vehicle distance Dm in congested travel as the target inter-vehicle distance Dtgt corresponding to the learning vehicle speed Vm at which the effective "inter-vehicle distance of other vehicle" used in the calculation of the inter-vehicle distance Dm in congested travel is obtained, as the learning vehicle speed Vm.

[0096] Further, in a case where the host vehicle HV is in a congested environment and the host vehicle HV is in a stopped state or is traveling at an extremely low speed (i.e., in a case where the host vehicle speed Vh is below the extremely low speed determination value VLth), the control device DS obtains the "inter-vehicle distances D11 to D15" described below (refer to FIG. 6) as the inter-vehicle distance of other vehicle at the time of stop based on the "camera object information or fusion object information". Figure 4

[0097] Inter-vehicle distance D11: inter-vehicle distance of a rear vehicle Cl (1st other vehicle) which is an other vehicle stopped on the host lane and directly behind the host vehicle HV in a stopped state.

[0098] Inter-vehicle distance D12: inter-vehicle distance of an other vehicle C3 (1st other vehicle) which is an other vehicle stopped on the left adjacent lane and in a stopped state, and an other vehicle C2 (2nd other vehicle) which is an other vehicle stopped directly in front of the other vehicle C3.

[0099] Inter-vehicle distance D13: inter-vehicle distance of an other vehicle C4 (1st other vehicle) which is an other vehicle stopped on the left adjacent lane and in a stopped state, and an other vehicle C3 (2nd other vehicle) which is an other vehicle stopped directly in front of the other vehicle C4.

[0100] Inter-vehicle distance D14: inter-vehicle distance of an other vehicle C6 (1st other vehicle) which is an other vehicle stopped on the right adjacent lane and in a stopped state, and an other vehicle C5 (2nd other vehicle) which is an other vehicle stopped directly in front of the other vehicle C6.

[0101] Inter-vehicle distance D15: inter-vehicle distance of an other vehicle C7 (1st other vehicle) which is an other vehicle stopped on the right adjacent lane and in a stopped state, and an other vehicle C6 (2nd other vehicle) which is an other vehicle stopped directly in front of the other vehicle C7.​

[0102] In this case as well, among the inter-vehicle distances, in the case where the other vehicle is a vehicle of a predetermined vehicle type different from the vehicle type • category of the host vehicle HV (in this case, a passenger car), the control device DS considers the inter-vehicle distance ensured by the other vehicle to be an effective "inter-vehicle distance at stop of other vehicle". For example, in the above-described example shown in FIG. 6, if the other vehicle C3 is a truck, the control device DS considers the inter-vehicle distance D12 to be an effective "inter-vehicle distance at stop of other vehicle". Figure 5 In the above-described example shown in FIG. 6, if the other vehicle C3 is a truck, the control device DS considers the inter-vehicle distance D12 to be an effective "inter-vehicle distance at stop of other vehicle".

[0103] The control device DS, in the case where one or more (preferably two or more) effective "inter-vehicle distances at stop of other vehicle" are obtained, calculates a preferred inter-vehicle distance D0 at stop based on the effective "inter-vehicle distances at stop of other vehicle". For example, the control device DS calculates an average value of the effective "inter-vehicle distances at stop of other vehicle" as the preferred inter-vehicle distance D0 at stop. Also, the control device DS stores (learns) the preferred inter-vehicle distance D0 at stop as the target inter-vehicle distance Dtgt corresponding to the case where the host vehicle speed Vh is "0".

[0104] After the preferred inter-vehicle distance Dm during congestion and the preferred inter-vehicle distance D0 at stop are obtained (learned), the control device DS calculates the target inter-vehicle distance Dtgt during the period of congestion travel based on the preferred inter-vehicle distance Dm during congestion, the preferred inter-vehicle distance D0 at stop, the learning vehicle speed Vm, and the host vehicle speed Vh at the current time point, according to, for example, a linear interpolation method with respect to the host vehicle speed Vh.

[0105] Further, in the case where the preferred inter-vehicle distance D0 at stop is not obtained, the control device DS sets the preferred inter-vehicle distance D0 at stop to an initial value D0int set in advance. Therefore, in the case where the host vehicle HV stops in a state where the preferred inter-vehicle distance Dm during congestion is learned but the preferred inter-vehicle distance D0 at stop is not learned, the inter-vehicle distance of the host vehicle HV from the preceding vehicle PV becomes a value close to the initial value D0int of the preferred inter-vehicle distance at stop. In this case, in the case where the preferred inter-vehicle distance D0 at stop is learned before a predetermined waiting time elapses from the time point at which the host vehicle HV stops, if the learned (learned) preferred inter-vehicle distance D0 at stop is shorter than the actual host vehicle inter-vehicle distance Dact, the control device DS causes the host vehicle HV to travel slowly, thereby causing the actual host vehicle inter-vehicle distance Dact to coincide with the learned preferred inter-vehicle distance D0 at stop.

[0106] As such, according to the present control device DS, since the actual inter-vehicle distance Dact is adjusted based on the inter-vehicle distance ensured by the other vehicle in the vicinity of the host vehicle HV (other-vehicle inter-vehicle distance), the possibility of the driver feeling a sense of strangeness is reduced. Further, according to the present control device DS, the stop-time preferred inter-vehicle distance D0 is a distance calculated based on the distance between the stopped vehicle (vehicle not in the period of travel) and the stopped vehicle (vehicle not in the period of travel), so the stop-time preferred inter-vehicle distance D0 becomes a distance suitable as an "inter-vehicle distance that should be maintained when the host vehicle HV is stopped".

[0107] (Detailed Operation)

[0108] The CPU of the DSECU (hereinafter, in the case where it is indicated as "CPU", it refers to the CPU of the DSECU unless otherwise specified) executes the routine illustrated by the flowchart in Figures 8 to 11 and Figure 5 every predetermined time.

[0109] 1. ACC Travel Control (Inter-vehicle Distance Control)

[0110] When it becomes a predetermined timing, the CPU starts processing from step 500 of Figure 10 , and determines whether or not the value of the ACC execution flag XACC is "1" in step 510. The value of the ACC execution flag XACC is set to "1" by a routine not illustrated when the ACC start condition is satisfied, and is set to "0" by a routine not illustrated when the ACC end condition is satisfied. The ACC start condition is satisfied, for example, when an ACC start request is generated by the operation of the ACC operation switch 31 in a state where ACC is not being executed (i.e., in the case where the value of the ACC execution flag XACC is set to "0"), and the host vehicle speed Vh at that point of time is higher than the congestion travel determination vehicle speed VJth. The ACC end condition is satisfied, for example, when an ACC end request is generated by the operation of the ACC operation switch 31 in the case where the value of the ACC execution flag XACC is set to "1".

[0111] Further, the ACC execution flag XACC is set to "0" by an initialization routine not illustrated executed by the CPU when the start switch (e.g., the ignition · key · switch, the preparation switch, etc.) of the host vehicle HV, which is not illustrated, is changed from the off position to the on position.

[0112] If the value of the XACC flag is "1" during ACC execution, the CPU determines "yes" in step 510 and proceeds to step 520 to determine whether there is a preceding vehicle (i.e., a vehicle to be followed) in the current lane. For example, if there is another vehicle traveling directly in front of the current vehicle in the current lane, and the distance between the other vehicle and the current vehicle is within a predetermined threshold distance, the CPU determines that other vehicle as the vehicle to be followed.

[0113] If a following vehicle is present, the CPU proceeds from step 520 to 530 to determine whether the value of the ACC permission flag XALW is "1". Regarding the value of the ACC permission flag XALW, it is set to "1" when the value of the flag XACC changes from "0" to "1" during ACC execution, and is set to "0" when a predetermined waiting time has elapsed since the vehicle (HV) stopped after passing through ACC (see below). Figure 11 (Step 1090). Furthermore, the value of the ACC permission sign XALW is set to "1" if the driver initiated a start-up operation when its value was "0" (see below). Figure 6 Step 1170).

[0114] After ACC starts, the ACC permission flag XALW is normally set to "1". In this case, the CPU determines "yes" in step 530 and proceeds to step 540 to determine whether the value of the congestion warning flag XJ is "0". The value of the congestion warning flag XJ is set to "0" when the value of the ACC execution flag XACC changes from "0" to "1". Furthermore, regarding the value of the congestion warning flag XJ, when the value of the ACC execution flag XACC is "1" (i.e., during ACC execution), it is changed to "1" when the vehicle speed Vh becomes below the congestion judgment speed VJth (see below). Figure 7 Step 640) When the vehicle speed Vh becomes higher than the congestion driving judgment speed VJth, it is changed to "0" (see below). Figure 6 Step 730).

[0115] If the value of the XJ indicator is "0" during congested driving, the CPU determines "yes" in step 540 and proceeds to step 550, executing the process described later. Figure 7 The subroutine shown is used to obtain (calculate) the target inter-vehicle distance Dtgt for normal driving. After that, the CPU proceeds to step 570.

[0116] Conversely, if the value of the XJ flag is "1" during congested driving, the CPU determines "No" in step 540 and proceeds to step 560, executing the process described later. Figure 3The CPU proceeds to step 570.

[0117] In step 570, the CPU acquires (measures) the above-described inter-vehicle distance Dact of the host vehicle based on the fused object information (actual inter-vehicle distance between the host vehicle HV and the preceding vehicle PV located directly in front of the host vehicle HV). In addition, the CPU acquires the relative speed Vrelative of the preceding vehicle PV with respect to the host vehicle HV based on the fused object information. Further, the relative speed Vrelative takes a positive value in the case where the preceding vehicle PV is departing from the host vehicle HV. Figure 5

[0118] Next, the CPU proceeds to step 580, and calculates the target acceleration Gtgt according to the following Equation (1) and Equation (2). The target inter-vehicle distance Dtgt in Equation (1) is the target inter-vehicle distance acquired in either one of step 550 and step 560. K1 and K2 in Equation (2) are predetermined positive gains (coefficients). In addition, an acceleration term (K3 · dVrelative / dt) can also be added to the right side of Equation (2).

[0119] Inter-vehicle distance deviation ΔD = Inter-vehicle distance Dact of host vehicle - Target inter-vehicle distance Dtgt … (1)

[0120] Target acceleration Gtgt = K1 · ΔD + K2 · Vrelative … (2)

[0121] Next, the CPU proceeds to step 590, and controls the acceleration of the host vehicle HV so that the actual acceleration (amount of change in the host vehicle speed Vh per unit time) of the host vehicle HV coincides with the target acceleration Gtgt by transmitting instructions to the powertrain ECU 40 and the brake ECU 50. Thus, inter-vehicle distance control is performed to accelerate or decelerate the host vehicle HV so that the inter-vehicle distance Dact of the host vehicle coincides with the target inter-vehicle distance Dtgt. Thereafter, the CPU proceeds to step 595, and temporarily ends the routine.

[0122] In addition, in the case where the CPU determines "NO" in either one of step 510 to step 530, the CPU proceeds directly from the step in which the determination is "NO" to step 595.

[0123] 2. Acquisition of target inter-vehicle distance for normal travel

[0124] As described above, the CPU acquires (calculates) the target inter-vehicle distance for normal travel by executing the subroutine shown in Figure 6 when the CPU proceeds to step 550. More specifically, the CPU acquires the target inter-vehicle distance for normal travel by executing the subroutine shown in Figure 6 when the CPU proceeds to step 550 from​Figure 5 Step 600 begins processing and proceeds to step 610, where it is determined whether the vehicle speed Vh is higher than the congestion-prone driving speed VJth. If the vehicle speed Vh is higher than the congestion-prone driving speed VJth, the CPU determines "yes" in step 610, and proceeds to the following steps 620 and 630, then proceeds to step 695, temporarily ending this routine.

[0125] Step 620: The CPU reads the target workshop time Ttgt set by the driver.

[0126] Step 630: The CPU sets the target workshop distance Dtgt as the product of the target workshop time Ttgt and the vehicle speed Vh.

[0127] Conversely, when the CPU proceeds to step 610, if the vehicle speed Vh is below the congestion determination speed VJth, the CPU determines "No" in step 610 and proceeds to step 640. In step 640, the CPU sets the value of the congestion flag XJ to "1" and proceeds to step 695. Furthermore, in this case, the target inter-vehicle distance Dtgt is set as the product of the target inter-vehicle time Ttgt and the vehicle speed Vh.

[0128] 3. Obtaining the target inter-vehicle distance for congested driving

[0129] As mentioned above, the CPU advances to Figure 7 In step 560, by executing Figure 7 The subroutine shown is used to obtain (calculate) the target inter-vehicle distance for congested driving. More specifically, when the CPU proceeds to step 560, it... Figure 8 Step 700 begins processing and proceeds to step 710, where it is determined whether the vehicle speed Vh is below the congestion driving determination speed VJth. If the vehicle speed Vh is below the congestion driving determination speed VJth, the CPU determines "yes" in step 710 and proceeds to step 720.

[0130] In step 720, the CPU obtains (calculates) the target inter-vehicle distance Dtgt based on the data stored in lookup table M1 and the vehicle speed Vh at the current time. Lookup table M1 specifies the relationship between the vehicle speed Vh and the target inter-vehicle distance Dtgt. The CPU calculates the target inter-vehicle distance Dtgt according to the following formulas (3) to (5) based on linear interpolation. After that, the CPU proceeds to step 795 and temporarily terminates this routine. In addition, DJth is the target inter-vehicle distance Dtgt when the vehicle speed Vh is the congestion driving determination speed VJth, which is preset. Vm is the learning speed Vm mentioned above, and Dm is the preferred inter-vehicle distance in congestion driving mentioned above. These values ​​(Vm, Dm) are determined by the following...Figure 9 The routine of the above-described stop-time preferred inter-vehicle distance D0 is learned. D0 is the stop-time preferred inter-vehicle distance D0 described above, which is learned by the routine described later Figure 9 The routine of the above-described stop-time preferred inter-vehicle distance D0 is learned. D0 is the stop-time preferred inter-vehicle distance D0 described above, which is learned by the routine described later

[0131] (Case 1) In the case where the value of the congestion travel learning flag XDm is "1" (i.e., in the case where the vehicle speed Vm and the congestion travel preferred inter-vehicle distance Dm have been learned and not cleared, in the congestion travel)

[0132] • When 0 ≤ Vh≤ Vm

[0133] Dtgt = D0 + (Dm - D0) • (Vh / Vm)... (3)

[0134] • When Vm < Vh≤ VJth

[0135] Dtgt = Dm + (DJth - Dm) • (Vh - Vm) / (Vjth - Vm)... (4)

[0136] (Case 2) In the case where the value of the congestion travel learning flag XDm is "0" (i.e., in the case where the vehicle speed Vm and the congestion travel preferred inter-vehicle distance Dm are not in the state where they have been learned, cleared, in the congestion travel)

[0137] Dtgt = D0 + (DJth - D0) • (Vh / VJth)... (5)

[0138] On the other hand, in the case where the host vehicle speed Vh is higher than the congestion travel determination vehicle speed VJth, the CPU determines "No" in step 710, proceeds to step 730, and performs the processing described below. Thereafter, the CPU proceeds to step 795, and temporarily ends the present routine. Further, in this case, the target inter-vehicle distance Dtgt is set to the product of the target inter-vehicle time Ttgt and the host vehicle speed Vh.

[0139] • The CPU sets the value of the congestion travel flag XJ to "0".

[0140] • The CPU sets the value of the stop-time learning flag XD0 to "0". The value of the stop-time learning flag XD0 is set to "1" when the above-described stop-time preferred inter-vehicle distance D0 is calculated (learned) (refer to step 980 of the routine described later Figure 7 ).

[0141] • The CPU sets the value of the congestion travel learning flag XDm to "0".

[0142] • The CPU sets the value of the stop-time preferred inter-vehicle distance D0 stored in the look-up table Ml to the initial value D0int.

[0143] • The CPU clears the "learned vehicle speed Vm and the inter-vehicle distance Dm preferred in congested travel" stored in the look-up table Ml, respectively.

[0144] 4. Learning of the inter-vehicle distance Dm preferred in congested travel and the learned vehicle speed Vm

[0145] Next, the learning method of the inter-vehicle distance Dm preferred in congested travel and the learned vehicle speed Vm stored in the look-up table Ml (refer to Figure 8 Step 720) will be described. When it becomes a predetermined timing, the CPU starts processing from Step 800 of Figure 3 , and determines in Step 810 whether the value of the ACC execution flag XACC is "1". In the case where the value of the ACC execution flag XACC is "1", the CPU proceeds to Step 820, and determines whether the value of the congested travel flag XJ is "1".

[0146] In the case where the value of the congested travel flag XJ is "1", the CPU determines "Yes" in Step 820 and proceeds to Step 830, and determines whether the value of the congested travel learning flag XDm is "0". That is, the CPU determines whether the value of the inter-vehicle distance Dm preferred in congested travel has not been learned after the host vehicle HV is involved in this time's congestion (from the time point at which the host vehicle speed Vh becomes the congested travel determination vehicle speed VJth or lower).

[0147] In the case where the value of the congested travel learning flag XDm is "0", the CPU proceeds to Step 840, and determines whether the host vehicle speed Vh is greater than "a positive extremely low speed determination value VLth" (that is, the host vehicle HV is not stopped) and smaller than "the congested travel determination vehicle speed VJth". In the case where the determination condition of Step 840 is satisfied, the CPU proceeds from Step 840 to Step 850, and acquires the distance that can be acquired among the above-described inter-vehicle distances of other vehicles in congested travel (refer to the inter-vehicle distances Dl to D5 exemplified in Figure 7 ).

[0148] Next, the CPU proceeds to step 860 and determines whether at least two of the successfully obtained inter-vehicle distances in congested traffic are valid. Specifically, the CPU determines whether the vehicle type of the other vehicle located behind the current vehicle in the direction of travel, separated by inter-vehicle distances, is a predetermined vehicle type (such as trucks, buses, and two-wheeled motor vehicles) different from the current vehicle's HV (i.e., passenger car). If the vehicle type of the other vehicle is determined to be a predetermined vehicle type, the inter-vehicle distance in congested traffic is determined to be "not valid (invalid)". Furthermore, the CPU determines whether the vehicle type of the other vehicle traveling directly behind the current vehicle's HV is a predetermined vehicle type different from the current vehicle's HV. If the vehicle type of the other vehicle is determined to be a predetermined vehicle type different from the current vehicle's HV, the inter-vehicle distance between the other vehicle and the current vehicle is determined to be invalid as "inter-vehicle distances in congested traffic".

[0149] Having obtained two or more valid "inter-vehicle distances in congested traffic," the CPU learns the optimal inter-vehicle distance Dm and the learning speed Vm in congested traffic by performing the "processing steps 870 to 890" as described below. Afterward, the CPU proceeds to step 895, temporarily terminating this routine.

[0150] Step 870: The CPU learns the average value of the effective "inter-vehicle distances of other vehicles in congested driving" as the optimal inter-vehicle distance Dm in congested driving (i.e., stores it in the appropriate position in lookup table M1).

[0151] Step 880: The CPU stores the vehicle speed Vh at this time point as the learning speed Vm (i.e., stores it in the appropriate position in lookup table M1).

[0152] Step 890: The CPU sets the value of the learning flag XDm in congested driving to "1".

[0153] Furthermore, if the CPU determines "no" in any of steps 810 to 840, and if it determines "no" in step 860, it proceeds directly to step 895 from the step where "no" was determined.

[0154] 5. Learning the optimal workshop distance D0 when stopping.

[0155] Next, for the data stored in lookup table M1 (refer to...) Figure 9 The learning method for the preferred workshop distance D0 during the stopping process in step 720) will be explained. When the predetermined timing is reached, the CPU starts from... Figure 4The process starts at step 900, and at step 910, it is determined whether the value of the ACC execution flag XACC is "1". When the value of the ACC execution flag XACC is "1", the CPU proceeds to step 920, and it is determined whether the value of the congestion travel flag XJ is "1".

[0156] When the value of the congestion travel flag XJ is "1", the CPU determines "Yes" at step 920 and proceeds to step 930, and it is determined whether the value of the stop-time learning flag XD0 is "0". That is, it is determined whether the value of the stop-time preferred inter-vehicle distance D0 has not been learned since the host vehicle HV was involved in the congestion this time (from the time point at which the host vehicle speed Vh became the congestion travel determination speed VJth or less).

[0157] When the value of the stop-time learning flag XD0 is "0", the CPU proceeds to step 940, and it is determined whether the host vehicle speed Vh at the current time point is "0" or more and is less than the extremely low speed determination value VLth. Also, at step 940, the CPU can determine whether the host vehicle speed Vh is "0".

[0158] When the determination condition at step 940 is satisfied, the CPU proceeds from step 940 to step 950, and based on the "camera object information or fused object information", the distance that can be acquired among the above-described stop-time other-vehicle inter-vehicle distances (refer to Figure 10 The illustrated inter-vehicle distances D11 to D15).

[0159] Next, the CPU proceeds to step 960, and it is determined whether two or more of the successfully acquired stop-time other-vehicle inter-vehicle distances are valid. That is, it is determined whether the vehicle type of the other vehicle that stopped behind in the travel direction with the stop-time other-vehicle inter-vehicle distance is a predetermined vehicle type (large vehicles such as trucks and buses, and two-wheeled motor vehicles, etc.) that is different from the vehicle type (i.e., passenger car) of the host vehicle HV, and when it is determined that the vehicle type of the other vehicle is the predetermined vehicle type, the stop-time other-vehicle inter-vehicle distance is determined to be "not valid (invalid)". Also, it is determined whether the vehicle type of the other vehicle that stopped directly behind the host vehicle HV is a predetermined vehicle type that is different from the vehicle type of the host vehicle HV, and when it is determined that the other vehicle is the predetermined vehicle type that is different from the vehicle type of the host vehicle HV, it is determined that the inter-vehicle distance between the other vehicle and the host vehicle is not valid as a "stop-time other-vehicle inter-vehicle distance".

[0160] Having obtained two or more valid "distances between other vehicles at the time of stopping", the CPU learns the preferred distance D0 at the time of stopping by performing the "processing in steps 970 and 980" as described below. Afterwards, the CPU proceeds to step 995, temporarily terminating this routine.

[0161] Step 970: The CPU learns the average value of the valid "distances between other vehicles at the time of stopping" as the preferred distance between vehicles at the time of stopping (i.e., stores it in the appropriate position in lookup table M1).

[0162] Step 980: The CPU sets the value of the learning flag XD0 at stop to "1".

[0163] Furthermore, if the CPU determines "no" in any of steps 910 to 940, and if it determines "no" in step 960, it proceeds directly to step 995 from the step where "no" was determined.

[0164] 6. Adjustment of workshop distance when stopped

[0165] When the scheduled time arrives, the CPU starts from... Figure 11 The process begins at step 1000. In step 1010, it is determined whether the value of the ACC execution flag XACC is "1". If the value of the ACC execution flag XACC is "1", the CPU proceeds to step 1020 to determine whether the value of the congested driving flag XJ is "1".

[0166] If the value of the XJ indicator is "1" during congested driving, the CPU determines "yes" in step 1020 and proceeds to step 1030 to determine whether the vehicle speed Vh is "0" (i.e., whether the vehicle HV is in a stopped state).

[0167] When the vehicle speed Vh is "0", the CPU determines "yes" in step 1030 and proceeds to step 1035 to determine whether the value of the ACC permission flag XALW is "1". If the value of the ACC permission flag XALW is "1", the CPU determines "yes" in step 1035 and proceeds to step 1040 to determine whether the current time point is before the point where "a predetermined waiting time has elapsed since the time point when the vehicle speed Vh changed from a value greater than "0" to "0" (i.e., the stop time point)". If the current time point is between the stop time point and the time point where the waiting time has elapsed since the stop time point, the CPU proceeds from step 1040 to step 1050 to determine whether the value of the stop learning flag XD0 is "1".

[0168] In the case where the value of the stop-time learning flag XD0 is "1" (i.e., in the case where the value of the stop-time preferred inter-vehicle distance D0 has been learned), the CPU determines "Yes" in step 1050 and proceeds to step 1060, and determines whether the inter-vehicle distance of the own vehicle at the current time point (actual inter-vehicle distance) Dact is greater than the "learned stop-time preferred inter-vehicle distance D0".

[0169] In the case where the inter-vehicle distance of the own vehicle at the current time point Dact is greater than the "learned stop-time preferred inter-vehicle distance D0", the CPU determines "Yes" in step 1060 and proceeds to step 1070, and causes the own vehicle HV to travel slowly. Thereby, the own vehicle HV advances at an extremely low speed. Next, the CPU proceeds to step 1080, and determines whether the inter-vehicle distance of the own vehicle Dact has become "learned stop-time preferred inter-vehicle distance D0" or less.

[0170] In the case where the inter-vehicle distance of the own vehicle Dact has not become "learned stop-time preferred inter-vehicle distance D0" or less, the CPU returns from step 1080 to 1070, and causes the own vehicle HV to travel slowly. As a result, the inter-vehicle distance of the own vehicle Dact approaches "learned stop-time preferred inter-vehicle distance D0". By repeating this processing, when the inter-vehicle distance of the own vehicle Dact coincides with the "learned stop-time preferred inter-vehicle distance D0", the CPU determines "Yes" in step 1080, and proceeds to step 1085.

[0171] In step 1085, the CPU stores the inter-vehicle distance of the own vehicle Dact as the actual stop inter-vehicle distance Dstp. Next, the CPU proceeds to step 1090, and sets the value of the ACC permission flag XALW to "0". At this time, the CPU transmits an instruction to the brake ECU 50, so as to increase the brake force. That is, the CPU performs brake hold control. Thereafter, the CPU proceeds to step 1095, and temporarily ends the present routine.

[0172] Further, in the case where the value of the stop-time learning flag XD0 is not "1" when the CPU proceeds to step 1050 (i.e., in the case where the value of the stop-time preferred inter-vehicle distance D0 has not been learned), the CPU determines "No" in step 1050 and proceeds directly to step 1095. Further, in the case where the inter-vehicle distance of the own vehicle at the current time point Dact is "learned stop-time preferred inter-vehicle distance D0" or less when the CPU proceeds to step 1060, the CPU determines "No" in step 1060 and proceeds directly to step 1085. Further, in the case where the current time point is after the time point at which the waiting time has elapsed from the stop time point when the CPU proceeds to step 1040, the CPU determines "No" in step 1040 and proceeds directly to step 1085.

[0173] Furthermore, if the CPU determines "no" in any of steps 1010 to 1035, it proceeds directly to step 1095 from the step where "no" is determined.

[0174] 7. ACC Start-up Control (Start-up control when the vehicle speed is "0")

[0175] When the scheduled time arrives, the CPU starts from... Figure 5 The process begins at step 1100. In step 1110, it is determined whether the value of the ACC execution flag XACC is "1". If the value of the ACC execution flag XACC is "1", the CPU determines "yes" in step 1110 and proceeds to step 1120 to determine whether the value of the congested driving flag XJ is "1".

[0176] If the value of the XJ indicator is "1" during congested driving, the CPU determines "yes" in step 1120 and proceeds to step 1130 to determine whether the vehicle speed Vh is "0". If the vehicle speed Vh is "0", the CPU determines "yes" in step 1130 and proceeds to step 1140 to determine whether the value of the ACC permission indicator XALW is "0".

[0177] If the ACC clearance flag XALW is "0", the CPU determines "yes" in step 1140 and proceeds to step 1150 to determine whether the vehicle's inter-vehicle distance Dact is greater than the value obtained by adding the threshold distance Dth to the actual stopping inter-vehicle distance Dstp. If the preceding vehicle PV starts moving after both the preceding vehicle PV and the current vehicle HV have stopped, the vehicle's inter-vehicle distance Dact will become greater than the value obtained by adding the threshold distance Dth to the actual stopping inter-vehicle distance Dstp.

[0178] In this case, the CPU determines "yes" in step 1150 and proceeds to step 1160 to determine whether the driver has performed a start-up operation. More specifically, the CPU determines that the driver has performed a start-up operation when a predetermined operation of the driver's ACC operation switch 31 generates a request to restart the ACC, or when the accelerator pedal is operated and the accelerator pedal operation amount AP changes from "0" to a value greater than "0".

[0179] If the driver initiates the start-up operation, the CPU determines "yes" in step 1160 and proceeds to step 1170, setting the ACC permission flag XALW to "1". As a result, because the CPU... Figure 4 If the condition is "yes" in step 530, the vehicle starts moving as per steps 580 and 590. Afterward, the CPU proceeds to step 1195, temporarily ending the current routine.

[0180] Further, in a case where the CPU determines "NO" in any one of steps 1110 to 1160, the CPU proceeds to 1195 from the step in which the determination is "NO".

[0181] As described above, the present control device DS acquires

[0182] • an inter-vehicle distance between a first other vehicle stopped in the vicinity of the host vehicle and a second other vehicle stopped in front of the first other vehicle (refer to D12 to D15 of FIG. 12), and Figure 4

[0183] • an inter-vehicle distance between the first other vehicle stopped in the vicinity of the host vehicle and the host vehicle stopped in front of the first other vehicle (refer to D11 of FIG. 11) ​

[0184] as the inter-vehicle distance of other vehicles at the time of stop.

[0185] Further, the present control device DS sets the inter-vehicle distance at the time of stop, D0, which is used as the target inter-vehicle distance Dtgt at the time of stop of the host vehicle, in accordance with the acquired inter-vehicle distance of other vehicles at the time of stop. Therefore, it is possible to control the target inter-vehicle distance at the time of stop of the host vehicle to a preferable distance.

[0186] Further, in a case where the acquired inter-vehicle distance of other vehicles at the time of stop is an inter-vehicle distance maintained by other vehicles of a predetermined vehicle type (a vehicle type different from the vehicle type of the host vehicle), the inter-vehicle distance of other vehicles at the time of stop is not considered valid and is not reflected on the inter-vehicle distance at the time of stop, D0. Therefore, it is possible to control the target inter-vehicle distance at the time of stop of the host vehicle to a more preferable distance.

[0187] The present application is not limited to the above-described embodiments, and various modifications can be employed within the scope of the present application. For example, the present control device DS can be applied to the host vehicle in a state where the driving mode is being changed from automatic driving to driving by a driver in an automatic driving vehicle.

[0188] ​​Moreover, the number of camera devices can be any number as long as information on objects in the surroundings of the host vehicle (a range of 360 degrees centered on the host vehicle) can be obtained, and in addition, a LiDAR can be mounted instead of the radar device, or in addition to the radar device. Furthermore, the host control device DS can also determine the stop-time preferred inter-vehicle distance D0 based on only the inter-vehicle distance D11 ensured between the other vehicle stopped immediately behind the host vehicle HV and the host vehicle HV. In this case, the host control device DS can set the stop-time preferred inter-vehicle distance D0 to the inter-vehicle distance D11, or can set the stop-time preferred inter-vehicle distance D0 to "a value obtained by adding a predetermined margin distance to the inter-vehicle distance D11".

Claims

1. A workshop distance control device, comprising: An information acquisition device acquires information about objects present in the vicinity of the vehicle; and The controller is capable of performing vehicle-to-vehicle distance control, which is based on the information to obtain the vehicle-to-vehicle distance between itself and a preceding vehicle located directly in front of it, and controls the vehicle in a manner that maintains the obtained vehicle-to-vehicle distance at a predetermined target vehicle-to-vehicle distance. The controller is configured as follows: Based on the aforementioned information, the inter-vehicle distance between a first other vehicle stopped around the vehicle and a second other vehicle stopped directly in front of the first other vehicle, or the vehicle stopped directly in front of the first other vehicle, is obtained as the inter-vehicle distance between other vehicles at the time of stopping. The preferred stopping distance, set based on the stopping distances of other vehicles, is used as the target stopping distance when the vehicle has stopped.

2. The workshop distance control device according to claim 1, The controller is configured as follows: Based on the information, it is determined whether the first other vehicle is a predetermined vehicle type. If the first other vehicle is determined to be the predetermined vehicle type, the distance between the first other vehicle determined to be the predetermined vehicle type and the second other vehicle stopped directly in front of the first other vehicle, and the distance between the first other vehicle determined to be the predetermined vehicle type and the vehicle itself stopped directly in front of the first other vehicle, are not reflected in the preferred distance at the time of stopping.

3. The workshop distance control device according to claim 1, The controller is configured as follows: When the vehicle's speed (i.e., the vehicle's current speed) is higher than the predetermined congestion-determining speed, the preferred stopping distance is returned to its initial value. Subsequently, if the preferred stopping distance is set again from the time the vehicle comes to a stop after decelerating via the vehicle distance control until a predetermined waiting period has elapsed, the vehicle is moved forward in such a way that the vehicle distance is consistent with the newly set preferred stopping distance.

4. The workshop distance control device according to claim 3, The controller is configured as follows: During the execution of the vehicle distance control, when the vehicle speed changes from a speed higher than the predetermined congestion judgment speed to a speed lower than the congestion judgment speed, the vehicle distance between a third other vehicle traveling around the vehicle and a fourth other vehicle traveling directly in front of the third other vehicle, or the vehicle traveling directly in front of the third other vehicle, is obtained based on the information as the vehicle distance between other vehicles in congestion. The vehicle speed at the time point when the inter-vehicle distance to other vehicles in the congested traffic is obtained is stored as the learning speed. The optimal inter-vehicle distance in congested traffic is calculated based on the obtained inter-vehicle distances of other vehicles. The optimal inter-vehicle distance during congested driving is stored in association with the learned vehicle speed. When the vehicle speed is lower than the learning speed, the target vehicle distance is determined based on the preferred distance between vehicles when stopped, the preferred distance between vehicles in congested traffic, the learning speed, and the vehicle speed.

5. A vehicle-to-vehicle distance control method, wherein the vehicle is controlled such that the vehicle-to-vehicle distance between itself and a preceding vehicle located directly in front of it is maintained at a predetermined target vehicle-to-vehicle distance. The workshop distance control method includes the following steps: The step of obtaining the inter-vehicle distance between a first other vehicle stopped around the vehicle and a second other vehicle stopped directly in front of the first other vehicle, or the vehicle stopped directly in front of the first other vehicle, as the inter-vehicle distance of the other vehicles at the time of stopping; The step of calculating the optimal stopping distance based on the obtained inter-vehicle distances at the time of stopping; and The step of using the preferred workshop distance when the vehicle is stopped as the target workshop distance when the vehicle is stopped.

6. A non-transitory storage medium storing a program. The program causes the computer installed in this vehicle to perform the following steps: The steps of controlling the vehicle in such a way that the vehicle-to-vehicle distance between the preceding vehicle located directly in front of the vehicle and the vehicle is maintained at a predetermined target vehicle-to-vehicle distance; The step of obtaining the inter-vehicle distance between a first other vehicle stopped around the vehicle and a second other vehicle stopped directly in front of the first other vehicle, or the vehicle stopped directly in front of the first other vehicle, as the inter-vehicle distance of the other vehicles at the time of stopping; The step of calculating the optimal stopping distance based on the obtained inter-vehicle distances at the time of stopping; and The step of using the preferred workshop distance at the time of stopping as the target workshop distance when the vehicle has stopped.

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