JP6948149B2 - Driving support device - Google Patents

Description

The present invention relates to a driving support device.

In recent years, automatic acceleration / deceleration control has been developed that recognizes a preceding vehicle by using a front recognition sensor such as a camera or radar and controls acceleration / deceleration so as to maintain an inter-vehicle distance from the preceding vehicle.

When approaching the preceding vehicle, this automatic acceleration / deceleration control decelerates by reducing the output of the engine or increasing the oil pressure of the friction brake to increase the distance between the vehicle and the preceding vehicle. In addition, when the distance between the vehicle and the preceding vehicle is widened or when the vehicle deviates from the traveling path of the own vehicle, the output of the engine is increased and the vehicle accelerates to a predetermined speed.

As a result, the vehicle can travel according to the surrounding vehicles while maintaining the inter-vehicle distance so as not to collide with the preceding vehicle.

Further, in automatic acceleration / deceleration control, there is known a technique for improving fuel efficiency and riding comfort by acquiring driving information by wireless communication from a vehicle in front traveling on the path of the own vehicle.

The device described in Patent Document 1 is an example thereof, and when the speed of the vehicle in front acquired by vehicle-to-vehicle communication is lower than that of the preceding vehicle, the tracking of the preceding vehicle is interrupted to maintain the speed of the own vehicle. We are trying to improve fuel efficiency.

As one of the means for acquiring the traveling information of the vehicle in front, a method using communication via a public line and a server is known. Unlike the method using vehicle-to-vehicle communication, traveling information can be acquired regardless of the distance between vehicles by using a public line.

The device described in Patent Document 2 is an example thereof. When the traveling information of the vehicle in front is acquired by communication via a server and the deceleration of the vehicle in front is detected, the deceleration of the own vehicle is coordinated before the deceleration of the preceding vehicle is detected. I try to do it.

Japanese Unexamined Patent Publication No. 2013-67365 Japanese Unexamined Patent Publication No. 2012-35795

However, when the deceleration of the vehicle in front is detected, there is a problem that it is not always possible to decelerate the own vehicle to improve fuel efficiency and riding comfort.

An object of the present invention is to provide a driving support device capable of improving fuel efficiency and riding comfort.

In order to achieve the above object, the present invention includes a propagable determination unit for determining whether or not the deceleration of the first front vehicle indicating a vehicle two or more vehicles in front of the own vehicle can propagate to the own vehicle, and the above. A driving support device including a front vehicle speed control unit that decelerates the own vehicle when it is determined that the deceleration of the first front vehicle can propagate to the own vehicle and the first front vehicle decelerates. The propagation possibility determination unit is one vehicle in front of the own vehicle in a deceleration propagation range indicating a range of time and position at which the deceleration of the first front vehicle propagates due to the deceleration of the first front vehicle. When the preceding vehicle indicating the vehicle decelerates and the distance from the own vehicle to the preceding vehicle is equal to or less than the threshold value, it is determined that the deceleration of the preceding vehicle can propagate to the own vehicle .

According to the present invention, it is an object of the present invention to provide a driving support device capable of improving fuel efficiency and riding comfort. Issues, configurations and effects other than those described above will be clarified by the description of the following embodiments.

It is a figure which shows the schematic structure of the driving support device in 1st Embodiment. It is a block diagram of the driving support device in 1st Embodiment. It is a block diagram of the acceleration / deceleration control device in the 1st Embodiment. It is a flowchart which shows the operation of the acceleration / deceleration control device in 1st Embodiment. It is a block diagram of the propagable determination part in 1st Embodiment. It is a flowchart which shows the operation of the propagable determination part in 1st Embodiment. It is a figure explaining the operation of the propagable determination part in 1st Embodiment. It is a block diagram of the front vehicle speed control part in 1st Embodiment. It is a flowchart which shows the operation of the front vehicle speed control part in 1st Embodiment. It is a figure explaining the operation of the driving support device in the 1st comparative example. It is a figure explaining the operation of the driving support device which can acquire the driving information of the vehicle in front in the 2nd comparative example. It is a figure explaining the operation of the front vehicle speed control part in 1st Embodiment. It is a figure explaining the operation of the front vehicle speed control part in 1st Embodiment. It is a figure which shows the schematic structure of the driving support device in 2nd Embodiment. It is a figure explaining the operation of the propagable determination part in the 2nd Embodiment. It is a figure which shows the schematic structure of the driving support device in 3rd Embodiment. It is a figure explaining the operation of the propagable determination part in the 3rd Embodiment. It is a figure which shows the schematic structure of the driving support device in 4th Embodiment. It is a figure explaining the operation of the propagable determination part in 4th Embodiment. It is a figure explaining the operation of the front vehicle speed control part in 5th Embodiment. It is a figure for demonstrating the operation which cancels the determination that it is propagable based on the inter-vehicle time. It is a figure for demonstrating the operation which cancels the determination that the propagation is possible based on no deceleration of the preceding vehicle.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. In the embodiments described below, the present invention is described by taking as an example a case where an engine, which is an internal combustion engine, is applied to an automatic driving device of a vehicle as a sole drive source. However, the present invention describes an engine and an electric motor. It can also be applied to driving support devices for electric vehicles such as hybrid vehicles (passenger vehicles), freight vehicles such as hybrid trucks, and shared vehicles such as hybrid buses.

(First Embodiment)
FIG. 1 is a diagram showing a configuration of a driving support device according to the first embodiment. The broken line arrow in FIG. 1 indicates the signal flow.

The vehicle has an engine 1 that drives the vehicle, a brake 2 that brakes the vehicle, a transmission 3 that continuously shifts the driving force generated by the engine 1, and power between the transmission 3 and the drive wheels 4. The clutch 5 to be transmitted, the engine control device 6 that controls the combustion state of the engine 1 to change the power generated by the engine 1, and the brake control that controls the hydraulic pressure of the brake 2 to change the braking force generated by the brake 2. The device 7, the transmission control device 8 that controls the rotation speed of the transmission 3 to change the gear ratio, and controls the power transmission of the clutch 5, and the front recognition sensor 9 (camera,) that detects an object in front of the vehicle. Radar, etc.), a vehicle speed sensor 10 that detects the speed of the vehicle, an acceleration / deceleration control device 11 that commands the operation of the engine control device 6, the brake control device 7, and the transmission control device 8, and the position of the own vehicle. The GPS sensor 12 and the communication unit 13 (communication unit 13) that acquires the traveling information of the vehicle in front traveling on the path of the vehicle and the road information (information such as the average speed between the vehicle and the vehicle in front) around the vehicle and the vehicle in front. It is equipped with a receiver for wireless, optical beacon system, etc.).

The power generated by the combustion of fuel by the engine 1 is transmitted to the transmission 3, and after shifting by the belt-type transmission mechanism inside the transmission 3, left and right via the clutch 5 and the differential mechanism 14. It is transmitted to the drive wheel 4 of the vehicle and becomes a driving force for driving the vehicle. A brake 2 for generating a braking force of the vehicle is provided in the vicinity of the drive wheels 4. The brake 2 is provided with a hydraulic booster, and the drive wheels 4 are pressed by the hydraulic operating force generated by the hydraulic booster to generate a frictional force. As a result, kinetic energy can be converted into thermal energy to brake the vehicle.

In FIG. 1, the acceleration / deceleration control device 11 is composed of a CPU (Central Processing Unit), a memory, and the like, executes a control program, and transfers to the engine control device 6, the brake control device 7, and the transmission control device 8. Calculate the command value of. Thereby, the acceleration / deceleration of the vehicle can be controlled.

In FIG. 1, the engine control device 6 is composed of a CPU, a memory, and the like, and executes a control program to calculate a fuel supply amount and an air supply amount of the engine 1. Thereby, the controlling driving force generated by the engine 1 can be controlled.

In FIG. 1, the brake control device 7 is composed of a CPU, a memory, and the like, and executes a control program to calculate the oil pressure of the brake 2. Thereby, the braking force generated by the brake 2 can be controlled.

In FIG. 1, the transmission control device 8 is composed of a CPU, a memory, and the like, and executes a control program to calculate the oil pressures of the transmission 3 and the clutch 5. Thereby, the gear ratio of the transmission 3 and the power transmission of the clutch 5 can be controlled.

As shown in FIG. 1, the acceleration / deceleration control device 11 includes a front recognition sensor 9 that detects an object in front of the vehicle, a vehicle speed sensor 10 that detects the speed of the vehicle, a GPS sensor 12 that detects the position of the own vehicle, and the own vehicle. The communication unit 13 and the like for acquiring the traveling information of the vehicle in front traveling on the path and the road information around the own vehicle and the vehicle in front are connected.

The front recognition sensor 9 detects the preceding vehicle detection information such as the relative distance (inter-vehicle distance), relative speed, position and speed of the preceding vehicle traveling in front of the vehicle, and the preceding vehicle detection signal (signal indicating the preceding vehicle detection information). Can be output as.

The communication unit 13 can acquire travel information from a vehicle in front traveling on the path of the own vehicle by communication via a public line and a server. As a result, traveling information can be acquired regardless of the distance between the own vehicle and the vehicle in front. The traveling information includes the position information and the speed information of the vehicle in front. Further, it is possible to acquire road information around the own vehicle and the vehicle in front based on the position information of the own vehicle detected by the GPS sensor 12 and the position information included in the traveling information of the vehicle in front. The road information includes the traffic conditions between the own vehicle and the vehicle in front, that is, the average speed in the section.

The acceleration / deceleration control device 11 calculates using the preceding vehicle detection signal of the front recognition sensor 9 and the speed signal of the vehicle speed sensor 10 (a signal indicating the speed of the own vehicle), and calculates the engine control device 6 and the brake control device. The control driving force is commanded to 7 and the transmission control device 8. When the distance between the vehicle and the preceding vehicle detected by the front recognition sensor 9 is shortened, the vehicle is instructed to decelerate. When the distance between the preceding vehicle and the preceding vehicle detected by the front recognition sensor 9 is large, or when the preceding vehicle disappears, the vehicle is instructed to accelerate to a predetermined speed. As a result, it is possible to control the traveling according to the surrounding vehicles without getting too close to the preceding vehicle. Further, based on the traveling information acquired from the communication unit 13, the deceleration of the vehicle in front is detected, and when it is determined that the deceleration of the vehicle in front can propagate to the own vehicle, the front recognition sensor 9 detects the deceleration of the preceding vehicle. By starting the deceleration of the own vehicle even before the operation, the fuel efficiency and the riding comfort can be improved.

FIG. 2 is a block diagram showing a configuration of a driving support device according to the first embodiment. The driving support device is provided with an acceleration / deceleration control device 11, an engine control device 6, a brake control device 7, a transmission control device 8, an engine 1, a brake 2, a transmission 3, and a clutch 5. Hereinafter, the flow of calculation of the driving support device according to the first embodiment will be described with reference to FIG.

The acceleration / deceleration control device 11 includes a preceding vehicle detection signal output by the front recognition sensor 9, a speed signal (vehicle speed signal) output by the vehicle speed sensor 10, and a position signal (signal indicating the position of the own vehicle) output by the GPS sensor 12. ), The driving information signal of the vehicle in front (signal indicating driving information such as the position and speed of the vehicle in front) output by the communication unit 13, and the road information signal (signal indicating road information) output by the communication unit 13. Based on, a target torque signal indicating the target value of the torque generated by the engine 1, a target rotation speed signal indicating the target value of the rotation speed of the engine 1, and a target system indicating the target value of the braking force generated by the brake 2. Calculate the power signal. This makes it possible to control the acceleration / deceleration of the vehicle.

The engine control device 6 calculates a fuel / air supply amount signal that commands a fuel / air supply amount to the engine 1 based on the target torque signal output by the acceleration / deceleration control device 11. Thereby, the torque generated by the engine 1 can be controlled.

Based on the target rotation speed signal output by the acceleration / deceleration control device 11, the transmission control device 8 has a transmission oil pressure signal that commands the oil supply to the transmission 3 and a clutch oil pressure that commands the oil pressure to be supplied to the clutch 5. Calculate with the signal. Thereby, the gear ratio of the transmission 3, that is, the rotation speed of the engine 1 and the power transmission state of the clutch 5 can be controlled.

The brake control device 7 calculates a brake oil pressure signal that commands the oil pressure to be supplied to the brake 2 based on the target braking force signal output by the acceleration / deceleration control device 11. Thereby, the braking force generated by the brake 2 can be controlled.

FIG. 3 is a block diagram showing the configuration of the acceleration / deceleration control device 11 according to the first embodiment. FIG. 4 is a flowchart showing the operation of the acceleration / deceleration control device 11 according to the first embodiment. Hereinafter, the acceleration / deceleration control operation of the first embodiment will be described with reference to FIGS. 3 and 4. The CPU of the acceleration / deceleration control device 11 constitutes the acceleration / deceleration control block shown in FIG. 3 according to the software form of the microcomputer, and the operation (addition) shown in FIG. 4 is performed while the ignition key switch (not shown) of the vehicle is on. The deceleration control program) is repeatedly executed.

The acceleration / deceleration control device 11 includes a preceding vehicle speed control unit 21, a propagation possibility determination unit 22, a forward vehicle speed control unit 23, a control content determination unit 26, a target engine speed calculation unit 27, a target engine torque calculation unit 28, and a target. A brake braking force calculation unit 29 is provided. The operation of each part will be described below.

In step S001, the preceding vehicle speed control unit 21 calculates the preceding vehicle target acceleration signal from the preceding vehicle detection signal input from the front recognition sensor 9 and the speed signal (vehicle speed signal) input from the vehicle speed sensor 10. .. The target acceleration of the preceding vehicle is the acceleration for realizing the following running of the preceding vehicle. When approaching the preceding vehicle, it decelerates by outputting a negative target acceleration and travels so as to increase the inter-vehicle distance. When the vehicle moves away from the preceding vehicle, it accelerates by outputting a positive target acceleration and travels so as to reduce the inter-vehicle distance. When the speed of the own vehicle exceeds the set value, the target acceleration is lowered and the vehicle travels so that the speed does not exceed the set value.

In step S002, the propagating possibility determination unit 22 includes the preceding vehicle detection information input from the front recognition sensor 9, the position signal input from the GPS sensor 12, and the travel information signal of the vehicle in front input from the communication unit 13. A road information signal input from the communication unit 13 and a propagation possibility determination signal (a signal indicating whether or not the deceleration of the vehicle in front can propagate to the own vehicle) are calculated.

In other words, the propagation possibility determination unit 22 determines whether or not the deceleration of the front vehicle (first front vehicle) indicating the vehicle two or more vehicles in front of the own vehicle can propagate to the own vehicle. This makes it possible to determine whether the deceleration of the vehicle in front can propagate to the own vehicle.

FIG. 5 is a block diagram showing a configuration of the propagable determination unit 22 according to the first embodiment. FIG. 6 is a flowchart showing the operation of the propagable determination unit 22 in the first embodiment. Hereinafter, the operations of the propagable determination unit 22 and S002 of the first embodiment will be described with reference to FIGS. 5 and 6.

In step S101, the inter-vehicle time history storage unit 31 determines the position of the own vehicle indicated by the position signal input from the GPS sensor 12 and the position of the vehicle in front indicated by the traveling information signal of the vehicle in front input from the communication unit 13. The speed between the own vehicle and the vehicle in front is calculated from the speed of the vehicle in front indicated by the travel information signal of the vehicle in front input from the communication unit 13, and the history is stored. The inter-vehicle time is the value obtained by dividing the distance between the own vehicle and the vehicle in front by the speed of the vehicle in front.

In step S102, it is determined whether or not the history of the inter-vehicle time stored in step S101 is expanded by a predetermined value or more. If it is determined that the image has not been expanded, the process proceeds to step S102. If it is determined that the vehicle has expanded, the process proceeds to step S112, and the preceding vehicle propagation possible determination unit 32 determines that the preceding vehicle can propagate, or the own vehicle propagation possible determination unit 33 determines that the own vehicle can propagate. If it has been determined, the determination that it can be propagated is canceled. As a result, it is possible to prevent the own vehicle from decelerating when the vehicle in front, which cannot propagate, decelerates, resulting in deterioration of fuel efficiency and riding comfort.

In addition, instead of the inter-vehicle time, the propagation possibility determination unit 22 determines that the distance from the own vehicle to the preceding vehicle (first forward vehicle) at the second timing after the first timing is the own at the first timing. When the distance from the vehicle to the vehicle in front becomes larger than the distance, the determination that the deceleration of the vehicle in front can propagate to the own vehicle may be canceled.

In step S103, the front vehicle deceleration detection unit 34 detects the deceleration of the front vehicle from the speed information included in the travel information of the front vehicle input from the communication unit 13. When the rate of change of the speed information is negative and smaller than the predetermined value, it is judged that the vehicle has decelerated. If the deceleration of the vehicle in front is detected in step S103, the process proceeds to step S104. If the deceleration of the vehicle in front is not detected in step S103, the process proceeds to step S105.

In step S104, the deceleration propagation range determination unit 35 is forward from the position information included in the traveling information of the vehicle in front in step S103, the road information input from the communication unit 13, and the detection result of the vehicle deceleration detection unit 34 in front. Determine the deceleration propagation range of the vehicle. The deceleration propagation range is a range of positions and times in which each vehicle traveling between the own vehicle and the vehicle in front decelerates when the deceleration of the vehicle in front can propagate.

In step S105, the preceding vehicle propagation possibility determination unit 32 determines whether or not the preceding vehicle has passed the deceleration propagation range defined in step S104 without decelerating. If it is determined to be negative in step S105, the process proceeds to step S106. In step S105, if it is determined that the preceding vehicle has passed the deceleration propagation range without decelerating, the process proceeds to step S112, and if it is determined that the preceding vehicle or the own vehicle can propagate, it is possible to propagate. Cancel the judgment.

In other words, the propagation possibility determination unit 22 decelerates in the deceleration propagation range of the preceding vehicle indicating the vehicle immediately before the own vehicle even if the vehicle in front (first vehicle in front) decelerates (step S103: YES). If not (step S105: YES), the determination that the deceleration of the vehicle in front can propagate to the own vehicle is canceled (step S112). As a result, it is possible to prevent the own vehicle from decelerating when the vehicle in front, which cannot propagate, decelerates, resulting in deterioration of fuel efficiency and riding comfort.

In step S106, when the preceding vehicle propagation possibility determination unit 32 detects the deceleration of the preceding vehicle within the deceleration propagation range determined in step S104, the vehicle proceeds to step S107, and the deceleration of the preceding vehicle can propagate to the preceding vehicle. Judge that there is. If the deceleration of the preceding vehicle is not detected within the deceleration propagation range defined in step S104, the process proceeds to step S108.

If it is determined in step S108 that the deceleration of the vehicle in front can propagate to the preceding vehicle, the process proceeds to step S109, and the own vehicle propagating possibility determination unit 33 is input from the front recognition sensor 9 in step S109. When the inter-vehicle distance indicated by the preceding vehicle detection signal is equal to or less than a predetermined value, the process proceeds to step S110, and it is determined that the deceleration of the vehicle in front can propagate to the own vehicle. This makes it possible to determine whether the deceleration of the vehicle in front can propagate to the own vehicle. If the inter-vehicle distance is equal to or greater than a predetermined value in step S109, the process proceeds to step S111, and the determination that the deceleration of the vehicle in front can propagate to the own vehicle is canceled.

In this way, the propagation possibility determination unit 22 can propagate the deceleration of the preceding vehicle to the own vehicle based on the deceleration propagation range indicating the time and position range in which the deceleration of the preceding vehicle (first front vehicle) propagates. Judge whether or not. Specifically, the propagation possibility determination unit 22 decelerates in the deceleration propagation range of the preceding vehicle indicating the vehicle immediately before the own vehicle due to the deceleration of the vehicle in front (first vehicle in front) (step S103: YES). If the distance from the own vehicle to the preceding vehicle is equal to or less than the threshold value (step S109: YES), it is determined that the deceleration of the vehicle in front can propagate to the own vehicle (step S110).

Note that FIG. 21 shows an operation in which the deceleration of the vehicle in front is determined to be able to propagate to the own vehicle, and then the time between the own vehicle and the vehicle in front is increased to cancel the determination of the possibility of propagation. Further, FIG. 22 shows an operation of canceling the propagation possibility determination without detecting the deceleration of the preceding vehicle in the deceleration propagation range after determining that the deceleration of the vehicle in front can propagate to the own vehicle.

FIG. 7 is a diagram for explaining the operation of the propagable determination unit 22 in the present embodiment, and shows the relationship between the position and the time.

Since the deceleration of the vehicle in front was detected at the position P02 at the time T01, the deceleration propagation range A01 is determined. The deceleration propagation speed V can generally be calculated by Eq. (1).

Here, Q2 = traffic volume after deceleration (unit: number of vehicles / unit time), Q1 = traffic volume before deceleration, K2 = traffic density after deceleration (unit: number of vehicles / unit distance), K1 = traffic density before deceleration Is.

Further, when the change in the traffic volume or the traffic density is minute, the deceleration propagation speed V can be calculated by the equation (2).

Here, δQ = minute change in traffic volume and δK = minute change in traffic density.

The statistical relationship between traffic volume and traffic density with respect to the traveling speed of a vehicle can be uniquely determined for each road. In addition, the statistical relationship on the right side of equation (2) with respect to the traveling speed of the vehicle can be uniquely determined for each road. Equation (2) is calculated from the average speed included in the road information, and the deceleration propagation range A01 is determined from the time T01 and the position P02 when the deceleration of the vehicle in front is detected and the deceleration propagation speed calculated by the equation (2). Can be done.

In other words, the propagable determination unit 22 decelerates based on the average speed of the vehicle between the own vehicle and the vehicle in front (the first vehicle in front), the position where the vehicle in front decelerates, and the timing when the vehicle in front decelerates. The propagation range A01 is calculated. In the example of FIG. 7, there is a range in the timing at which the deceleration of the vehicle in front propagates at a certain position. Thereby, for example, the deceleration propagation range can be determined by using the road information (average speed of the vehicle, etc.) provided by the traffic information center or the like.

As shown in FIG. 7, the deceleration propagation speed tends to decrease as the traveling speed of the vehicle increases. The reason is as follows. The inclination (time / position) of the vehicle trajectory shown in FIG. 7 corresponds to the reciprocal of the vehicle traveling speed, and as the vehicle traveling speed increases, the inclination of the vehicle trajectory shown in FIG. 7 decreases (gentlely). Become). On the other hand, the slope (time / position) of the straight line LN passing through the points (P01, T01) and the points (P02, T02) in FIG. 7 corresponds to the reciprocal of the deceleration propagation speed, and when the traveling speed of the vehicle increases, the straight line LN The absolute value of the slope of is large (becomes steep). Therefore, as the traveling speed of the vehicle increases, the deceleration propagation speed decreases.

At time T02, since the deceleration of the preceding vehicle was detected at the position P01 within the deceleration propagation range A01, it is determined that the deceleration of the preceding vehicle can propagate the preceding vehicle. Further, since the inter-vehicle distance between the preceding vehicle and the own vehicle is equal to or less than a predetermined value, it is determined that the deceleration of the preceding vehicle can be propagated to the own vehicle after the time T02. This makes it possible to determine whether the deceleration of the vehicle in front can propagate to the own vehicle.

Returning to FIG. 4, in step S003, the front vehicle speed control unit 23 uses the speed signal (vehicle speed signal) input from the vehicle speed sensor 10, the position signal input from the GPS sensor 12, and the front vehicle input from the communication unit 13. The forward vehicle target acceleration signal is calculated from the vehicle traveling information signal and the propagable determination signal input from the propagable determination unit 22. The front vehicle target acceleration signal is a signal that mainly indicates the target acceleration of the own vehicle according to the speed of the vehicle in front. The details will be described later with reference to FIGS. 8 and 9.

In other words, the front vehicle speed control unit 23 determines that the deceleration of the front vehicle (first front vehicle) can propagate to the own vehicle, and when the front vehicle decelerates, the front vehicle decelerates. As a result, when the vehicle in front decelerates, the deceleration of the own vehicle can be accelerated to improve fuel efficiency and riding comfort.

FIG. 8 is a block diagram showing the configuration of the front vehicle speed control unit 23 according to the first embodiment. FIG. 9 is a flowchart showing the operation of the front vehicle speed control unit 23 in the first embodiment. Hereinafter, the operations of the front vehicle speed control unit 23 and step S003 of the first embodiment will be described with reference to FIGS. 8 and 9.

In step S201, the switching block 101 outputs an invalid value (for example, null) as a forward vehicle target acceleration signal when the propagable determination signal input from the propagable determination unit 22 is negative. If the propagation possibility determination signal is valid in step S201, the process proceeds to step S202.

In step S202, the inter-vehicle time calculation unit 102 includes a speed signal included in the traveling information signal of the vehicle in front input from the communication unit 13 and a position signal included in the traveling information signal of the vehicle in front input from the communication unit 13. , The inter-vehicle time between the own vehicle and the vehicle in front is calculated from the position signal input from the GPS sensor 12. The inter-vehicle time is calculated by dividing the distance between the vehicle in front and the own vehicle by the speed of the vehicle in front.

In step S203, the deceleration determination unit 103 calculates a deceleration determination signal (a signal indicating whether or not the vehicle in front is decelerating) from the speed information included in the travel information signal of the vehicle in front input from the communication unit 13. If the rate of change of speed information is negative and is less than or equal to a predetermined value, it is determined that the vehicle is decelerating. If it is determined in step S203 that the vehicle is decelerating, the process proceeds to step S204, and the latch unit 104 stores the inter-vehicle time when the vehicle in front starts decelerating. If it is determined that the vehicle is not decelerating, the process proceeds to S206.

In step 205, when the deceleration determination signal input from the deceleration determination unit 103 indicates that there is deceleration, the flip-flop 105 switches the output of the switching block 106 to an acceleration equivalent to the emblem (engine brake).

In step S206, when the comparison unit 107 determines that the inter-vehicle time has become larger than that at the start of deceleration of the vehicle ahead, and in step S207, the comparison unit 108 determines that the speed of the own vehicle has become smaller than that of the vehicle ahead. In step S208, the flip-flop 105 switches the output of the switching block 106 to an invalid value.

Instead of the inter-vehicle time, the front vehicle speed control unit 23 uses the front vehicle speed control unit 23 to determine the distance from the own vehicle to the front vehicle at the second timing after the first timing at which the front vehicle (first front vehicle) starts decelerating. However, if the distance from the own vehicle to the vehicle in front at the first timing is larger and the speed of the own vehicle at the second timing is less than or equal to the speed of the vehicle ahead, even if the deceleration of the own vehicle is released. good.

Returning to FIG. 4, in step S003, when the distance to the vehicle in front is short, the deceleration may be insufficient at the acceleration corresponding to the engine braking, and the vehicle may come too close to the vehicle in front. Therefore, when the distance between the vehicle in front and the own vehicle is closer than a predetermined value, a value smaller than the equivalent of the engine braking may be output as the target acceleration to the vehicle in front. As a result, the vehicle can be sufficiently decelerated with respect to the vehicle in front, so that the riding comfort can be improved.

Further, in step S003, when the distance to the vehicle in front is long, if the deceleration of the vehicle in front is switched to the acceleration corresponding to the engine braking immediately after the detection, the deceleration becomes excessive and the vehicle may be too far from the vehicle in front. Therefore, when the distance between the vehicle in front and the own vehicle is longer than a predetermined value, the timing of switching the target acceleration to the vehicle in front to the equivalent of the engine braking may be delayed. As a result, excessive deceleration with respect to the vehicle in front can be suppressed, so that fuel efficiency can be improved.

When the vehicle in front (the first vehicle in front) decelerates, the front vehicle speed control unit 23 delays the timing of decelerating the vehicle or reduces the number of vehicles as the distance from the vehicle to the vehicle in front increases. The speed may be reduced. This is because the greater the distance from the own vehicle to the vehicle in front, the slower the deceleration of the vehicle in front reaches the own vehicle.

In steps S004 to S006 shown in FIG. 4, the control content determination unit 26 includes a preceding vehicle target acceleration signal input from the preceding vehicle speed control unit 21 and a front vehicle target acceleration signal input from the front vehicle speed control unit 23. The powertrain control command signal, which will be described later, is calculated from.

If the front vehicle target acceleration signal shows an effective value in step S004, the process proceeds to step S005, and the smaller of the preceding vehicle target acceleration signal and the front vehicle target acceleration signal, that is, the one with the stronger deceleration is the driving force of the vehicle. Is converted to and output as a power train control command signal (signal indicating the driving force of the vehicle).

If the front vehicle target acceleration signal shows an invalid value in step S004, the process proceeds to step S006, and the preceding vehicle target acceleration signal is converted into the driving force of the vehicle and output as a power train control command signal.

In step S007, the target engine torque calculation unit 28 calculates the target torque signal from the power train control command signal input from the control content determination unit 26. Specifically, the target torque signal is obtained by dividing the product of the driving force indicated by the power train control command signal input from the control content determination unit 26 and the speed indicated by the vehicle speed signal by the engine speed and limiting it to a positive value. And. The engine speed is calculated based on, for example, a signal output from the crank angle sensor.

In step S008, the target engine rotation speed calculation unit 27 calculates the target rotation speed signal from the power train control command signal input from the control content determination unit 26. Specifically, the most efficient rotation speed with respect to the output of the engine 1 obtained by integrating the driving force and the vehicle speed of the power train control command signal input from the control content determination unit 26 is set as the target rotation speed signal. do. When the powertrain state of the powertrain control command signal is engine stop / clutch release, the target rotation speed signal is set to zero.

In step S009, the target brake braking force calculation unit 29 calculates the target braking force signal from the power train control command signal input from the control content determination unit 26. By limiting the driving force of the power train control command signal input from the control content determination unit 26 to a negative value, it becomes a target braking force signal.

FIG. 10 is a diagram for explaining the operation of the driving support device in the first comparative example, and shows the relationship between the position and the time. FIG. 10 shows an example in which the deceleration of the vehicle in front propagates to the preceding vehicle. At time T11, the own vehicle also starts decelerating at the timing when the deceleration of the preceding vehicle is detected.

FIG. 11 is a diagram for explaining the operation of the driving support device capable of acquiring the traveling information of the vehicle in front in the second comparative example, and shows the relationship between the position and the time. FIG. 11 shows an example in which the deceleration of the vehicle in front does not propagate to the preceding vehicle. At time T21, the deceleration of the own vehicle is started at the timing when the deceleration of the vehicle in front is detected. Since the deceleration of the vehicle in front does not propagate to the own vehicle, useless deceleration at time T21 and re-acceleration to catch up with the preceding vehicle again occur at time T22, resulting in deterioration of fuel efficiency and riding comfort.

12 and 13 are views for explaining the operation of the front vehicle speed control unit 23 in the present embodiment, and show the relationship between the position and the time.

FIG. 12 shows an example in which the deceleration of the vehicle in front propagates to the preceding vehicle. Since the deceleration of the vehicle in front is detected at the time T31, the acceleration of the own vehicle is switched to correspond to the engine brake to start the deceleration, and the inter-vehicle time L31 at the time when the vehicle in front starts deceleration is stored. At time T32, the inter-vehicle time L32 became larger than the inter-vehicle time L31, and the speed of the own vehicle became smaller than the speed of the vehicle in front. Therefore, the acceleration was restored from the acceleration equivalent to the emblem to the acceleration for following the preceding vehicle. do. In this way, it is possible to accelerate the start of deceleration of the own vehicle and improve fuel efficiency and riding comfort.

FIG. 13 shows an example in which the deceleration of the vehicle in front does not propagate to the preceding vehicle. At time T41, the deceleration of the vehicle in front is detected, but since the deceleration of the vehicle in front does not propagate to the own vehicle, the vehicle following the preceding vehicle is continued. In this way, unnecessary acceleration / deceleration can be suppressed, and fuel efficiency and riding comfort can be improved.

(Second Embodiment)
FIG. 14 is a diagram showing a configuration of a driving support device according to the second embodiment. The second embodiment is a modification of a part of the configuration of the first embodiment described above. The same elements as those shown in FIGS. 1 to 13 are designated by the same reference numerals, and the differences will be mainly described below.

The driving support device according to the second embodiment includes a road-to-vehicle communication unit 201 (receiver of wireless, optical beacon system, etc.), and can acquire position information and display information of traffic signals in the vicinity of the own vehicle. can. The propagable determination unit 22 in the second embodiment uses the position information and the display information (information indicating the current color of the signal, etc.) of the traffic signal input from the road-to-vehicle communication unit 201 as the road information signal. And calculate the propagable judgment signal. The location information of the traffic signal may be acquired from a map database such as a car navigation system.

FIG. 15 is a diagram for explaining the operation of the propagable determination unit 22 in the second embodiment, and shows the relationship between the position and the time.

It is detected that the signal TS51 installed at the position P53 is red between the time T51 and the time T54 based on the position information and the display information of the traffic signal input from the road-to-vehicle communication unit 201. Further, at the time T52, since the deceleration of the vehicle in front is detected at the position P52 near the signal TS51, the deceleration propagation range A51 is determined. The deceleration propagation range A51 is in front of the vehicle in front, within a predetermined distance from the signal TS51, and between the time T51 and the time T54 when the signal TS51 is red, after the time T52 when the deceleration of the vehicle in front is detected. be.

In other words, the propagation possibility determination unit 22 decelerates and propagates based on the position of the traffic light, the position of the vehicle in front (the first vehicle in front), the timing when the vehicle in front decelerates, and the timing when the traffic signal changes from red to blue. The range A51 is calculated. This makes it possible to determine the deceleration propagation range using the position of the traffic light rather than the average speed of the vehicle.

At time T53, since the deceleration of the preceding vehicle was detected at the position P51 within the deceleration propagation range A52, it is determined that the deceleration of the preceding vehicle can propagate the preceding vehicle. Further, since the inter-vehicle distance between the preceding vehicle and the own vehicle is equal to or less than a predetermined value, it is determined that the deceleration of the preceding vehicle can be propagated to the own vehicle after the time T53. This makes it possible to determine whether the deceleration of the vehicle in front can propagate to the own vehicle.

(Third Embodiment)
FIG. 16 is a diagram showing a configuration of a driving support device according to a third embodiment. The third embodiment is a modification of a part of the configuration of the first embodiment described above. The same elements as those shown in FIGS. 1 to 13 are designated by the same reference numerals, and the differences will be mainly described below.

The driving support device according to the third embodiment includes the map information acquisition unit 301, and can acquire the position information of the tollhouse in the vicinity of the own vehicle. Specifically, the map information acquisition unit 301 acquires the location information of the tollhouse from the map database of the car navigation system, for example, but may acquire it from the cloud or the like. The propagation possibility determination unit 22 in the third embodiment calculates the propagation possibility determination signal using the position information of the tollhouse input from the map information acquisition unit 301 as the road information signal.

FIG. 17 is a diagram for explaining the operation of the propagable determination unit 22 in the third embodiment, and shows the relationship between the position and the time.

It is detected that the tollhouse TG61 is provided at the position P63 based on the position information of the tollhouse input from the map information acquisition unit 301. Further, at time T61, since the deceleration of the vehicle in front was detected at the position P61 near the tollhouse TG61, the deceleration propagation range A61 is determined.

The deceleration propagation range A61 is set in front of the vehicle in front, within a predetermined distance from the tollhouse TG61, and from the time T61 when the deceleration of the vehicle in front is detected to the time T63 when the vehicle in front passes through the tollhouse TG61.

In other words, the propagable determination unit 22 decelerates based on the position of the tollhouse, the position of the vehicle in front (the first vehicle in front), the timing when the vehicle in front decelerates, and the timing when the vehicle in front passes through the tollhouse. The propagation range A61 is calculated. This makes it possible to determine the deceleration propagation range using the position of the tollhouse rather than the average speed of the vehicle.

At time T62, since the deceleration of the preceding vehicle was detected at the position P62 within the deceleration propagation range A61, it is determined that the deceleration of the preceding vehicle can propagate the preceding vehicle. Further, since the inter-vehicle distance between the preceding vehicle and the own vehicle is equal to or less than a predetermined value, it is determined that the deceleration of the preceding vehicle can be propagated to the own vehicle after the time T62. This makes it possible to determine whether the deceleration of the vehicle in front can propagate to the own vehicle.

(Fourth Embodiment)
FIG. 18 is a diagram showing a configuration of a driving support device according to a fourth embodiment. The fourth embodiment is a modification of a part of the configuration of the first embodiment described above. The same elements as those shown in FIGS. 1 to 13 are designated by the same reference numerals, and the differences will be mainly described below.

The driving support device according to the fourth embodiment includes a traffic jam information acquisition unit 401 (wireless, optical beacon type receiver), and can acquire traffic jam information (information indicating a traffic jam section, etc.) in the vicinity of the own vehicle. can. The propagation possibility determination unit 22 in the fourth embodiment calculates the propagation possibility determination signal using the congestion information input from the congestion information acquisition unit 401 as the road information signal.

FIG. 19 is a diagram for explaining the operation of the propagable determination unit 22 in the fourth embodiment, and shows the relationship between the position and the time.

Based on the traffic jam information input from the traffic jam information acquisition unit 401, it is detected that there is a traffic jam in the traffic jam section TJ71. Further, at the time T71, since the deceleration of the vehicle in front was detected at the position P72 of 51 in the traffic jam section TJ71, the deceleration propagation range A71 is determined. The deceleration propagation range A71 is in front of the vehicle in front and within the range of the traffic jam section TJ71.

The propagation possibility determination unit 22 calculates the deceleration propagation range A71 based on the congestion section TJ71, the position of the vehicle in front (the first vehicle in front), and the timing when the vehicle in front decelerates. As a result, the deceleration propagation range can be determined using the congested section instead of the average speed of the vehicle.

At time T72, since the deceleration of the preceding vehicle was detected at the position P71 within the deceleration propagation range A72, it is determined that the deceleration of the preceding vehicle can propagate the preceding vehicle. Further, since the inter-vehicle distance between the preceding vehicle and the own vehicle is equal to or less than a predetermined value, it is determined that the deceleration of the preceding vehicle can be propagated to the own vehicle after the time T72. This makes it possible to determine whether the deceleration of the vehicle in front can propagate to the own vehicle.

(Fifth Embodiment)
FIG. 20 is a diagram illustrating the operation of the propagable determination unit 22 in the fifth embodiment, and shows the relationship between the position and the time.

The fifth embodiment is a modification of a part of the configuration of the first embodiment described above. The same elements as those shown in FIGS. 1 to 13 are designated by the same reference numerals, and the differences will be mainly described below.

The communication unit 13 in the fifth embodiment communicates from the first front vehicle traveling on the own vehicle path and the second front vehicle traveling in front of the first front vehicle via the public line and the server. You can get driving information with.

The front vehicle speed control unit 23 in the fifth embodiment of the second front vehicle determined to be propagable even if the deceleration of the first front vehicle determined to be propagable is not detected at time T81. Since the deceleration is detected, the deceleration of the own vehicle is started.

In this way, the propagation possibility determination unit 22 determines whether or not the deceleration of the second front vehicle in front of the first front vehicle can propagate to the own vehicle. Further, the front vehicle speed control unit 23 determines that the deceleration of the second front vehicle can propagate to the own vehicle, and when the second front vehicle decelerates, the own vehicle is decelerated. This can improve fuel efficiency and ride comfort.

As described above, according to the first to fifth embodiments, unnecessary acceleration / deceleration can be suppressed as compared with the conventional case. As a result, fuel efficiency and ride comfort can be improved.

The present invention is not limited to the above-described embodiment, and includes various modifications. For example, the above-described embodiment has been described in detail in order to explain the present invention in an easy-to-understand manner, and is not necessarily limited to the one including all the described configurations. Further, it is possible to replace a part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. Further, it is possible to add / delete / replace other configurations with respect to a part of the configurations of each embodiment.

Further, each of the above configurations, functions and the like may be realized by hardware by designing a part or all of them by, for example, an integrated circuit. Further, each of the above configurations, functions, and the like may be realized by software by the processor (microcomputer) interpreting and executing a program that realizes each function. Information such as programs, tables, and files that realize each function can be stored in a memory, a hard disk, a recording device such as an SSD (Solid State Drive), or a recording medium such as an IC card, an SD card, or a DVD.

The embodiment of the present invention may have the following aspects.

(1) A front vehicle traveling information detection unit that detects the traveling information of the first front vehicle traveling on the path of the own vehicle, and a propagation capable of determining whether the deceleration of the first front vehicle can propagate to the own vehicle. When the front vehicle traveling information detection unit detects the traveling information that the first front vehicle has decelerated when the determination unit and the propagation possible determination unit determine that the propagation is possible, the own vehicle is decelerated. A driving support device including a front vehicle speed control unit for driving the vehicle.

(2) The driving support device according to (1) further includes a road information acquisition unit that acquires road information around the own vehicle and the vehicle in front, and the propagation possibility determination unit precedes the own vehicle travel information. A driving support device characterized in that it is determined that the deceleration of the first front vehicle can propagate to the own vehicle based on the vehicle traveling information, the first vehicle traveling information, and the road information.

(3) In the driving support device according to (2), the propagation possibility determination unit includes a first front vehicle deceleration detection unit that detects deceleration of the first front vehicle based on the first vehicle travel information, and the first front vehicle deceleration detection unit. A preceding vehicle deceleration detecting unit that detects the deceleration of the preceding vehicle based on the preceding vehicle information, a deceleration propagation range determining unit that determines the deceleration propagation range of the first preceding vehicle based on the road information, and the preceding vehicle deceleration. When the detection timing of the detection unit is within the deceleration propagation range, the preceding vehicle propagation possible determination unit and the preceding vehicle propagation possible determination unit that determine that the deceleration of the first front vehicle can propagate to the preceding vehicle Determines that the deceleration of the first front vehicle can propagate to the own vehicle when the distance between the preceding vehicle and the own vehicle is within a predetermined range. A driving support device characterized by having a section and.

(4) In the driving support device according to (3), the road information is information on the average speed between the own vehicle and the vehicle in front, and the deceleration propagation range is calculated from the average speed. A driving support device characterized in that it is within the predicted range of deceleration propagation.

(5) In the driving support device according to (3), the road information is information on the position and display of a traffic signal, and the deceleration propagation range is a range closer to the own vehicle than the vehicle in front. A driving support device characterized in that the distance from the traffic signal is within a predetermined range and the display of the traffic signal is in the red range.

(6) In the driving support device according to (3), the road information is information on the position of the tollhouse, and the deceleration propagation range is set to a range on the own vehicle side of the vehicle in front and the tollhouse. A driving support device characterized in that the distance from the vehicle is within a predetermined range and the distance from the vehicle is within a range until the vehicle in front passes through the tollhouse.

(7) In the driving support device according to (3), the road information is information on a traffic jam or a congested section, and the deceleration propagation range is set to a range on the own vehicle side of the vehicle in front and the traffic jam section. A driving support device characterized by being in the range of.

(8) In the driving support device according to (2) to (7), the propagation possibility determination unit of the first front vehicle when the distance between the own vehicle and the front vehicle is expanded to a predetermined value or more. A driving support device characterized in that the determination that deceleration can propagate to the own vehicle is canceled.

(9) In the driving support device according to (3) to (8), the propagable determination unit is the preceding vehicle after the first front vehicle deceleration detection unit detects deceleration in the determination range detection unit. When the detection timing of the deceleration detection unit is not within the determination range determined based on the road information, the determination that the deceleration of the first front vehicle can propagate to the own vehicle is canceled. Driving support device.

(10) In the driving support device according to (2) to (9), when the communication unit receives the traveling information that the first front vehicle has decelerated, the front vehicle speed control unit causes the self. The self-vehicle so that the inter-vehicle time between the vehicle and the first front vehicle is the same as or wider than that at the start of deceleration of the first front vehicle, and the speed of the own vehicle is equal to or less than the current speed of the first front vehicle. A driving support device characterized by decelerating a vehicle.

(11) In the driving support device according to (2) to (10), the front vehicle speed control unit decelerates the first front vehicle by the propagation possibility determination unit and precedes the first front vehicle. When it is determined that the deceleration of the second front vehicle located can propagate to the own vehicle, even when the communication unit does not receive the driving information that the first front vehicle has decelerated, the front The vehicle speed control unit is a driving support device that decelerates the own vehicle when the communication unit receives travel information that the second front vehicle has decelerated.

(12) In the driving support device according to (2) to (11), the front vehicle speed control unit is the first when the communication unit receives travel information that the first front vehicle has decelerated. (I) A driving support device characterized in that the earlier the vehicle in front of the vehicle is, the later the deceleration start timing of the vehicle is delayed.

(13) In the driving support device according to (2) to (12), the front vehicle speed control unit is the first when the communication unit receives travel information that the first front vehicle has decelerated. (I) A driving support device characterized in that the deceleration of the own vehicle is weakened as the vehicle in front is ahead of the own vehicle.

(14) In the driving support device according to (2) to (13), the front vehicle travel information detection unit is a communication device that acquires the travel information of the first front vehicle via a public line. A characteristic driving support device.

According to the above (1) to (14), fuel efficiency and riding comfort can be improved by accelerating the start of deceleration of the own vehicle only when it is determined that the deceleration of the vehicle in front can propagate to the own vehicle.

1: Engine 2: Brake 3: Transmission 4: Drive wheel 5: Clutch 6: Engine control device 7: Brake control device 8: Transmission control device 9: Forward recognition sensor 10: Vehicle speed sensor 11: Acceleration / deceleration control device 12: GPS sensor 13: Communication unit 14: Differential mechanism 21: Preceding vehicle speed control unit 22: Propagation possible determination unit 23: Forward vehicle speed control unit 26: Control content determination unit 27: Target engine rotation speed calculation unit 28: Target engine torque Calculation unit 29: Target brake braking force calculation unit 31: Inter-vehicle time history storage unit 32: Preceding vehicle propagable determination unit 33: Own vehicle propagable determination unit 34: Forward vehicle deceleration detection unit 101: Switching block 102: Inter-vehicle time Calculation unit 103: Deceleration determination unit 104: Latch unit 105: Flip flop 106: Switching block 107: Comparison unit 108: Comparison unit 201: Road-to-vehicle communication unit 301: Map information acquisition unit 401: Congestion information acquisition unit

Claims (10)

A propagable determination unit that determines whether or not the deceleration of the first vehicle in front, which indicates a vehicle two or more vehicles in front of the own vehicle, can propagate to the own vehicle,
It is a driving support device including a front vehicle speed control unit that decelerates the own vehicle when it is determined that the deceleration of the first front vehicle can propagate to the own vehicle and the first front vehicle decelerates. hand,
The propagable determination unit
Due to the deceleration of the first vehicle in front, the preceding vehicle indicating the vehicle immediately before the own vehicle decelerates in the deceleration propagation range indicating the range of time and position at which the deceleration of the first vehicle propagates. A driving support device, characterized in that, when the distance from the own vehicle to the preceding vehicle is equal to or less than a threshold value, it is determined that the deceleration of the vehicle in front can propagate to the own vehicle. The driving support device according to claim 1.
The propagable determination unit
The deceleration propagation range is calculated based on the average speed of the vehicle between the own vehicle and the first front vehicle, the position where the first front vehicle decelerates, and the timing when the first front vehicle decelerates. A driving support device characterized by The driving support device according to claim 1.
The propagable determination unit
The deceleration propagation range is calculated based on the position of the traffic light, the position of the first vehicle in front, the timing when the first vehicle decelerates, and the timing when the traffic signal changes from red to blue. Driving support device. The driving support device according to claim 1.
The propagable determination unit
The deceleration propagation range is calculated based on the position of the tollhouse, the position of the first front vehicle, the timing when the first front vehicle decelerates, and the timing when the first front vehicle passes through the tollhouse. A driving support device characterized by this. The driving support device according to claim 1.
The propagable determination unit
A driving support device characterized in that the deceleration propagation range is calculated based on a traffic jam section, the position of the first front vehicle, and the timing at which the first front vehicle decelerates. The driving support device according to claim 1.
The propagable determination unit
The distance from the own vehicle to the first front vehicle at the second timing after the first timing becomes larger than the distance from the own vehicle to the first front vehicle at the first timing. In this case, the driving support device is characterized in that the determination that the deceleration of the first vehicle in front can propagate to the own vehicle is canceled. The driving support device according to claim 1.
The propagable determination unit
Even if the first front vehicle decelerates, if the preceding vehicle indicating the vehicle immediately before the own vehicle does not decelerate within the deceleration propagation range, the deceleration of the first front vehicle can propagate to the own vehicle. A driving support device characterized by canceling the judgment of. The driving support device according to claim 1.
The front vehicle speed control unit
The distance from the own vehicle to the first front vehicle at the second timing after the first timing at which the first front vehicle starts deceleration is the distance from the own vehicle at the first timing. When it becomes larger than the distance to the vehicle in front of 1 and the speed of the own vehicle at the second timing becomes equal to or less than the speed of the first vehicle in front, the deceleration of the own vehicle is released. Driving support device. The driving support device according to claim 1.
The propagable determination unit
It is determined whether or not the deceleration of the second front vehicle in front of the first front vehicle can propagate to the own vehicle.
The front vehicle speed control unit
A driving support device characterized in that when it is determined that the deceleration of the second front vehicle can propagate to the own vehicle and the second front vehicle decelerates, the own vehicle is decelerated. The driving support device according to claim 1.
The front vehicle speed control unit
When the first front vehicle decelerates, the greater the distance from the own vehicle to the first front vehicle, the later the timing of decelerating the own vehicle or the smaller the deceleration of the own vehicle. A characteristic driving support device.

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