Vehicle driving assistance device

Abstract

The present application provides a vehicle driving assistance device capable of performing follow-up control in a manner that makes the energy consumption of a drive device of the host vehicle less reliable. The vehicle driving assistance device (10) predicts the energy consumption when the first follow-up control is performed as a first energy consumption, and predicts the energy consumption when the second follow-up control is performed as a second energy consumption, and performs the second follow-up control when the second energy consumption is less than the first energy consumption, and performs the first follow-up control when the second energy consumption is the first energy consumption or more.

Description

Technical Field

[0001] This invention relates to a vehicle driving assistance device. Background Technology

[0002] A vehicle driving assistance device is known to perform following control, wherein the following control automatically controls the acceleration and deceleration of the vehicle based on the distance (inter-vehicle distance) between the vehicle and a preceding vehicle, thereby enabling the vehicle to follow the preceding vehicle. Furthermore, as one such vehicle driving assistance device, a vehicle driving assistance control is also known, wherein, when performing following control, in order to improve fuel efficiency, a threshold value (maximum inter-vehicle distance) for determining whether acceleration of the vehicle is necessary and a threshold value (minimum inter-vehicle distance) for determining whether deceleration of the vehicle is necessary are set based on the vehicle's speed (vehicle speed), and the vehicle is accelerated when the inter-vehicle distance increases to the maximum inter-vehicle distance, and decelerated by inertial travel when the inter-vehicle distance decreases to the minimum inter-vehicle distance (for example, see Patent Document 1).

[0003] Prior art literature

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent No. 4677945 Summary of the Invention

[0006] According to the aforementioned vehicle driving assistance device, inertial driving will continue from the point where the inter-vehicle distance decreases to the minimum inter-vehicle distance until the maximum inter-vehicle distance is reached. That is, the aforementioned vehicle driving assistance device aims to improve fuel efficiency by allowing the vehicle to decelerate through inertial driving until the inter-vehicle distance becomes larger.

[0007] Furthermore, since the air resistance experienced by the vehicle decreases when the inter-vehicle distance is shorter, a corresponding improvement in fuel consumption can be expected. Therefore, while, as with the aforementioned vehicle driving assistance devices, allowing the vehicle to decelerate through inertia until the inter-vehicle distance becomes larger would result in prolonged inertial driving and thus a corresponding improvement in fuel consumption, the larger inter-vehicle distance would also persist for an extended period, thereby increasing the air resistance experienced by the vehicle and potentially worsening fuel consumption. Therefore, even if the vehicle's deceleration through inertia is allowed until the inter-vehicle distance becomes larger, the overall fuel consumption may not necessarily improve.

[0008] Thus, depending on the vehicle's driving conditions, maintaining a fixed inter-vehicle distance while driving the vehicle can sometimes improve the overall fuel consumption rate compared to a situation where the vehicle is allowed to decelerate by inertia until the inter-vehicle distance increases. More generally, depending on the vehicle's driving conditions, maintaining a fixed inter-vehicle distance while driving the vehicle can sometimes reduce the energy consumption of the vehicle's drive system compared to a situation where the vehicle is allowed to decelerate by inertia until the inter-vehicle distance increases.

[0009] The purpose of this invention is to provide a vehicle driving assistance device that can perform follow control in a way that more reliably reduces the energy consumption of the vehicle's drive system.

[0010] The vehicle driving assistance device of the present invention includes a control device that performs a first following control and a second following control. The first following control is a control that automatically controls the acceleration and deceleration of the vehicle to follow the preceding vehicle in such a way that the vehicle-to-vehicle distance between the vehicle and the preceding vehicle is maintained within a first predetermined distance range. The second following control is a control that automatically accelerates and decelerates the vehicle to follow the preceding vehicle in such a way that the vehicle speed, which is the vehicle's speed, is maintained within a predetermined speed range or that the vehicle-to-vehicle distance is maintained within a second predetermined distance range that is larger than the first predetermined distance range.

[0011] The control device predicts the energy consumption of the vehicle's drive unit when the first follow control is executed as a first energy consumption, and predicts the energy consumption when the second follow control is executed as a second energy consumption. Furthermore, the control device is configured to execute the second follow control when the second energy consumption is less than the first energy consumption, and to execute the first follow control when the second energy consumption is greater than or equal to the first energy consumption.

[0012] When this vehicle follows a preceding vehicle, the air resistance experienced by the vehicle decreases, resulting in a corresponding reduction in the energy consumed by the vehicle's drive system (drive system energy consumption). Furthermore, disregarding air resistance, the energy consumption of the drive system of the vehicle traveling under the second follow control is lower compared to the case where the vehicle is traveling under the first follow control. However, when the vehicle is traveling under the second follow control, the inter-vehicle distance increases or decreases, resulting in an increase or decrease in air resistance. Therefore, considering air resistance, the energy consumption of the drive system of the vehicle traveling under the second follow control is not necessarily lower compared to the case where the vehicle is traveling under the first follow control.

[0013] According to the present invention, when the execution of the second follow control is requested, the energy consumption of the drive device when the first follow control is executed (first energy consumption) and the energy consumption of the drive device when the second follow control is executed (second energy consumption) are predicted, and the second follow control is executed only if the second energy consumption is less than the first energy consumption. Therefore, the energy consumption of the drive device can be reduced.

[0014] Furthermore, in the vehicle driving assistance device according to the present invention, the control device is configured to, for example, predict changes in the vehicle distance and the vehicle speed when the first following control is executed, and predict the energy consumption of the vehicle's drive device when the first following control is executed based on the vehicle distance and the vehicle speed under the assumption that the predicted changes have occurred, as the first energy consumption; and predict changes in the vehicle distance and the vehicle speed when the second following control is executed, and predict the energy consumption of the vehicle's drive device when the second following control is executed based on the assumption that the predicted changes have occurred, as the second energy consumption.

[0015] According to the present invention, as previously described, when the execution of the second follow control is requested, the first energy consumption and the second energy consumption are predicted, and the second follow control is executed only if the second energy consumption is less than the first energy consumption. Therefore, the energy consumption of the drive device can be reduced.

[0016] Furthermore, in the vehicle driving assistance device according to the present invention, the second following control is, for example, the control that, when the vehicle speed increases to reach the upper limit of the predetermined speed range, decelerates the vehicle by inertial travel, and accelerates the vehicle when the vehicle speed decreases to reach the lower limit of the predetermined speed range; or, when the inter-vehicle distance increases to reach the upper limit of the predetermined distance range, accelerates the vehicle, and decelerates the vehicle by inertial travel when the inter-vehicle distance decreases to reach the lower limit of the predetermined distance range.

[0017] According to the present invention, when the second following control is executed, the vehicle accelerates or decelerates by allowing the vehicle speed to increase or decrease within a predetermined speed range, or by allowing the inter-vehicle distance to increase or decrease within a second predetermined distance range, thereby further reducing the energy consumption of the drive unit.

[0018] Furthermore, in the vehicle driving assistance device according to the present invention, the second following control is, for example, the following control: when accelerating the vehicle, the vehicle is accelerated by optimal acceleration control, and when decelerating the vehicle, the vehicle is decelerated by inertial driving control, wherein the optimal acceleration control is the control that causes the drive device to operate at the point where the energy consumption of the drive device is minimized or approximately minimized, thereby accelerating the vehicle.

[0019] According to the present invention, since the drive unit is operated at the point where energy consumption is minimized or approximately minimized when the vehicle is accelerating, or the vehicle is allowed to continue moving due to inertia when it is decelerating, the energy consumption of the drive unit can be further reduced.

[0020] Furthermore, in the vehicle driving assistance device according to the present invention, the control device may also be configured to set the range of vehicle speeds allowed according to the driving environment of the vehicle as the predetermined speed range, or to set the range of inter-vehicle distances allowed according to the driving environment of the vehicle as the predetermined distance range.

[0021] When the second follow-up control is executed, if the vehicle speed becomes too slow or the inter-vehicle distance becomes too long, it may cause traffic congestion, which is not preferable. Furthermore, if the vehicle speed becomes too fast or the inter-vehicle distance becomes too short when the second follow-up control is executed, it is not preferable from the viewpoint of vehicle driving safety. Moreover, the permissible ranges for vehicle speed and inter-vehicle distance during the execution of the second follow-up control vary depending on the vehicle's driving environment. According to the present invention, since the predetermined speed range or the second predetermined distance range is set according to the vehicle's driving environment, the vehicle can be driven in a more appropriate manner through the second follow-up control.

[0022] Furthermore, in the vehicle driving assistance device according to the present invention, the control device may also be configured to predict the inter-vehicle distance and the vehicle speed when the first following control is executed based on the driving speed of the leading vehicle when the first following control is executed, and to predict the inter-vehicle distance and the vehicle speed when the second following control is executed based on the driving speed of the leading vehicle when the second following control is executed.

[0023] When both the first and second follow-up controls are executed, the inter-vehicle distance and the vehicle speed change due to the speed of the preceding vehicle. According to the present invention, since the inter-vehicle distance and the vehicle speed when the first follow-up control is executed are predicted based on the speed of the preceding vehicle when the first follow-up control is executed, and the inter-vehicle distance and the vehicle speed when the second follow-up control is executed are predicted based on the speed of the preceding vehicle when the second follow-up control is executed, the inter-vehicle distance and the vehicle speed can be predicted more accurately.

[0024] Furthermore, in the vehicle driving assistance device according to the present invention, the control device may also be configured to take into account the size of the preceding vehicle in the prediction of the first energy consumption and the second energy consumption.

[0025] The air resistance experienced by this vehicle varies depending on the size of the preceding vehicle. According to the present invention, since the size of the preceding vehicle is taken into account in the prediction of the first and second energy consumption, the first and second energy consumption can be predicted more accurately.

[0026] Furthermore, in the vehicle driving assistance device according to the present invention, the control device can also be configured to perform a third following control, which is a control that allows the vehicle to follow the preceding vehicle by accelerating or decelerating in a manner synchronized or substantially synchronized with the acceleration and deceleration of the preceding vehicle. This control further includes accelerating the vehicle through optimal acceleration control when accelerating and decelerating through inertial control when decelerating, wherein the optimal acceleration control is a control that operates the drive unit at an action point where the energy consumption of the vehicle's drive unit is minimized or substantially minimized. In this case, the control device is configured to perform the third following control when the predetermined execution condition is met, provided that the power output characteristics of the preceding vehicle's drive unit are the same or substantially the same as those of the vehicle's drive unit, and the preceding vehicle is traveling under the same control as the second or third following control. On the other hand, the control device is configured to execute either the first follower control or the second follower control when the predetermined execution condition is met and when the synchronization condition is not met.

[0027] When the power output characteristics of the leading vehicle's drive unit are the same or substantially the same as those of the vehicle's drive unit, and the leading vehicle is traveling under the same control as the third follow-up control, the energy consumption of the drive unit that propels the vehicle by synchronizing or substantially synchronizing acceleration and deceleration with the leading vehicle is reduced compared to when the vehicle is propelled by the first or second follow-up control. According to the present invention, since the leading vehicle is traveling under the same control as the third follow-up control when the power output characteristics of the leading vehicle's drive unit are the same or substantially the same as those of the vehicle's drive unit, the vehicle is propelled by the third follow-up control, thus further reducing the energy consumption of the drive unit.

[0028] Furthermore, in the vehicle driving assistance device according to the present invention, the control device may also be configured to perform a third following control, which is a control that allows the vehicle to follow the preceding vehicle by accelerating or decelerating in a manner synchronized or substantially synchronized with the acceleration and deceleration of the preceding vehicle, and by accelerating the vehicle through optimal acceleration control when accelerating the vehicle, and decelerating the vehicle through inertial driving control when decelerating the vehicle, wherein the optimal acceleration control is a control that accelerates the vehicle by operating the drive unit at an action point where the energy consumption of the vehicle's drive unit is minimized or substantially minimized. In this case, the control device is configured to, upon detecting that another vehicle has a drive unit with the same or substantially the same power output characteristics as the drive unit of the vehicle itself, and that the other vehicle is traveling under the same control as the second or the third follow control, move the vehicle behind the other vehicle and execute the third follow control.

[0029] According to the present invention, since the vehicle moves behind the other vehicle and drives through third follow control when it detects that the other vehicle has a drive unit with the same or substantially the same power output characteristics as the vehicle's drive unit, the energy consumption of the vehicle's drive unit can be further reduced.

[0030] In addition, the present invention provides a vehicle driving assistance method, wherein the vehicle driving assistance method enables the vehicle to drive through a first following control or a second following control, wherein the first following control is a control that automatically controls the acceleration and deceleration of the vehicle to maintain the inter-vehicle distance between the vehicle and the preceding vehicle at a predetermined distance, thereby enabling the vehicle to follow the preceding vehicle; the second following control is a control that automatically accelerates and decelerates the vehicle to maintain the vehicle speed (which is the vehicle's driving speed) within a predetermined speed range or to maintain the inter-vehicle distance within a predetermined distance range, thereby enabling the vehicle to follow the preceding vehicle.

[0031] In the vehicle driving assistance method of the present invention, when a predetermined execution condition requesting a reduction in the energy consumption of the vehicle's drive unit is met, the changes in the vehicle distance and the vehicle speed during the execution of the first following control are predicted, and the energy consumption of the vehicle's drive unit during the execution of the first following control is predicted as the first energy consumption based on the vehicle distance and the vehicle speed under the assumption that the changes have occurred in the predicted manner. Furthermore, the changes in the vehicle distance and the vehicle speed during the execution of the second following control are predicted, and the energy consumption during the execution of the second following control is predicted as the second energy consumption based on the vehicle distance and the vehicle speed under the assumption that the changes have occurred in the predicted manner. The second following control is executed when the second energy consumption is less than the first energy consumption, and the first following control is executed when the second energy consumption is greater than or equal to the first energy consumption.

[0032] According to the present invention, as previously described, the energy consumption of the drive device can be reduced.

[0033] In addition, the present invention provides a vehicle driving assistance program, which enables the vehicle to drive through a first following control or a second following control. The first following control is a control that automatically controls the acceleration and deceleration of the vehicle to maintain the inter-vehicle distance between the vehicle and the preceding vehicle at a predetermined distance, thereby enabling the vehicle to follow the preceding vehicle. The second following control is a control that automatically accelerates and decelerates the vehicle to maintain the vehicle speed (which is the vehicle's speed) within a predetermined speed range or to maintain the inter-vehicle distance within a predetermined distance range, thereby enabling the vehicle to follow the preceding vehicle.

[0034] The vehicle driving assistance program of the present invention, when a predetermined execution condition of requesting a reduction in the energy consumption of the vehicle's drive unit is met, predicts changes in the vehicle distance and vehicle speed when the first follow control is executed, and predicts the energy consumption of the vehicle's drive unit when the first follow control is executed based on the vehicle distance and vehicle speed under the assumption that the predicted changes have occurred, as the first energy consumption. Furthermore, it predicts changes in the vehicle distance and vehicle speed when the second follow control is executed, and predicts the energy consumption when the second follow control is executed based on the assumption that the predicted changes have occurred, as the second energy consumption. If the second energy consumption is less than the first energy consumption, the second follow control is executed; if the second energy consumption is greater than or equal to the first energy consumption, the first follow control is executed.

[0035] According to the present invention, as previously described, the energy consumption of the drive device can be reduced.

[0036] The elements of this invention are not limited to the embodiments described below with reference to the accompanying drawings. Other objects, features, and advantages of the invention will be readily understood from the description of embodiments of the invention. Attached Figure Description

[0037] Figure 1 The figure illustrates a vehicle driving assistance device according to an embodiment of the present invention and a vehicle equipped with the vehicle driving assistance device (the present vehicle).

[0038] Figure 2 A diagram showing the distance to the workshop ahead.

[0039] Figure 3 A diagram showing the vehicles surrounding this vehicle (surrounding vehicles).

[0040] Figure 4 A graph representing the energy efficiency of an internal combustion engine, the energy efficiency of an electric motor, and the driving torque.

[0041] Figure 5 A flowchart illustrating the routines executed by the vehicle driving assistance device according to an embodiment of the present invention.

[0042] Figure 6 A flowchart illustrating the routines executed by the vehicle driving assistance device according to an embodiment of the present invention.

[0043] Figure 7A flowchart illustrating the routines executed by the vehicle driving assistance device according to an embodiment of the present invention.

[0044] Figure 8 A flowchart illustrating the routines executed by the vehicle driving assistance device according to an embodiment of the present invention.

[0045] Figure 9 A flowchart illustrating the routines executed by the vehicle driving assistance device according to an embodiment of the present invention.

[0046] Figure 10 A flowchart illustrating the routines executed by the vehicle driving assistance device according to an embodiment of the present invention.

[0047] Figure 11 A flowchart illustrating the routines executed by the vehicle driving assistance device according to an embodiment of the present invention.

[0048] Figure 12 A flowchart illustrating the routines executed by the vehicle driving assistance device according to an embodiment of the present invention.

[0049] Figure 13 A flowchart illustrating the routines executed by the vehicle driving assistance device according to an embodiment of the present invention.

[0050] Figure 14 A flowchart illustrating the routines executed by the vehicle driving assistance device according to an embodiment of the present invention.

[0051] Figure 15 A diagram showing the relationship between workshop distance, vehicle speed, and energy consumption, using a defined mapping (lookup table).

[0052] Figure 16 A diagram showing the maximum allowable distance, the minimum allowable distance, and the allowable distance range (second predetermined distance range).

[0053] Figure 17 This diagram illustrates the calculation method for the energy consumption (second energy consumption) of the drive unit when the vehicle is driven by asynchronous switching follow control. Detailed Implementation

[0054] Hereinafter, a vehicle driving assistance device according to an embodiment of the present invention will be described with reference to the accompanying drawings. Figure 1 The diagram shows a vehicle driving assistance device 10 according to an embodiment of the present invention. The vehicle driving assistance device 10 is mounted on the vehicle 100.

[0055] <ECU>

[0056] The vehicle driving assistance device 10 includes an ECU 90 as a control device. ECU is short for Electronic Control Unit. The ECU 90 has a microcomputer as its main component. The microcomputer includes a CPU (Central Processing Unit), ROM (Read-Only Memory), RAM (Random Access Memory), non-volatile memory, and interfaces. The CPU performs various functions by executing instructions, programs, or routines stored in the ROM. In particular, the ROM stores a vehicle driving assistance program that executes the driving assistance control described later, and the CPU executes this driving assistance program to achieve the driving assistance control described later.

[0057] In particular, although the ECU90 stores the program for performing the driving assistance control described below in the ROM in advance, it can also be configured to wirelessly acquire and store such a program from an external device of the vehicle 100 via a receiving device, or to wirelessly update the stored program from an external device of the vehicle 100 via a receiving device.

[0058] <Vehicle Running Gear>

[0059] The vehicle 100 is equipped with a vehicle driving device 20. The vehicle driving device 20 is a device for driving, braking and steering the vehicle 100. In this example, the vehicle driving device 20 includes a driving device 21, a braking device 22 and a steering device 23.

[0060] <Driver>

[0061] The drive unit 21 is a device that outputs driving force (driving torque) applied to the vehicle 100 to make the vehicle 100 move. In this example, the drive unit 21 is composed of two power sources (first power source 211 and second power source 212) with different power output characteristics. For example, the first power source 211 and the second power source 212 are an internal combustion engine and an electric motor, respectively. The first power source 211 and the second power source 212 are electrically connected to the ECU 90. By controlling the operation of the first power source 211 and the second power source 212 respectively, the ECU 90 can control the driving force (driving torque) output from the first power source 211 and the second power source 212 respectively.

[0062] <Brake Device>

[0063] Braking device 22 is a device that outputs braking force (braking torque) to the vehicle 100 for braking the vehicle 100, such as a hydraulic brake device. Braking device 22 is electrically connected to ECU 90. ECU 90 controls the operation of braking device 22, thereby controlling the braking force (braking torque) output from braking device 22.

[0064] <Steering mechanism>

[0065] The steering device 23 is a device that outputs a steering force (steering torque) applied to the vehicle 100 for steering the vehicle 100, such as a power steering device. The steering device 23 is electrically connected to the ECU 90. By controlling the operation of the steering device 23, the ECU 90 can control the steering force (steering torque) output from the steering device 23.

[0066] <Sensors, etc.>

[0067] In addition, the vehicle 100 is equipped with an accelerator pedal 41, an accelerator pedal operation sensor 42, a brake pedal 43, a brake pedal operation sensor 44, a steering wheel 45, a steering angle sensor 46, a steering torque sensor 47, a vehicle speed detection device 48, a driving assistance operator 51, an efficiency-priority driving operator 52, a surrounding information detection device 60, and a transceiver device 70.

[0068] <Accelerator Pedal Operation Sensor>

[0069] Accelerator pedal operation amount sensor 42 is a sensor that detects the operation amount of accelerator pedal 41. Accelerator pedal operation amount sensor 42 is electrically connected to ECU 90. Accelerator pedal operation amount sensor 42 sends the detected operation amount information to ECU 90. Based on the information sent from accelerator pedal operation amount sensor 42, ECU 90 obtains the operation amount of accelerator pedal 41 as accelerator pedal operation amount AP.

[0070] In addition to performing the driving assistance control described later, ECU 90 calculates the drive torque that should be output from drive unit 21 based on the accelerator pedal operation amount AP and the vehicle speed (vehicle speed V1) of the vehicle 100, and sets it as the driver-demanded drive torque TQ1drv_req. ECU 90 then outputs a drive torque equivalent to this driver-demanded drive torque TQ1drv_req from drive unit 21. Furthermore, when performing the driving assistance control described later, ECU 90 sets the drive torque required to make the vehicle 100 travel in the desired manner as the system-demanded drive torque TQ1sys_req through this driving assistance control, and outputs a drive torque equivalent to this system-demanded drive torque TQ1sys_req from drive unit 21.

[0071] <Brake Pedal Operation Sensor>

[0072] Brake pedal operation amount sensor 44 is a sensor that detects the operation amount of brake pedal 43. Brake pedal operation amount sensor 44 is electrically connected to ECU 90. Brake pedal operation amount sensor 44 sends the detected operation amount information to ECU 90. ECU 90 obtains the operation amount of brake pedal 43 as brake pedal operation amount BP based on the information sent from brake pedal operation amount sensor 44.

[0073] In addition to performing the driving assistance control described later, the ECU 90 calculates the braking torque that should be applied to the vehicle 100 by the braking device 22 based on the brake pedal operation amount BP, and sets it as the driver-demanded braking torque TQ2drv_req. The ECU 90 then applies a braking torque equivalent to this driver-demanded braking torque TQ2drv_req to the vehicle 100 via the braking device 22. Furthermore, when performing the driving assistance control described later, the ECU 90 sets the braking torque required to make the vehicle 100 travel in the desired manner as the system-demanded braking torque TQ2sys_req, and applies a braking torque relative to the system-demanded braking torque TQ2sys_req to the vehicle 100 via the braking device 22.

[0074] <Steering angle sensor>

[0075] Steering angle sensor 46 is a sensor that detects the rotation angle of steering wheel 45 relative to the neutral position. Steering angle sensor 46 is electrically connected to ECU 90. Steering angle sensor 46 sends the detected rotation angle information of steering wheel 45 to ECU 90. ECU 90 uses this information to obtain the steering angle θ from the rotation angle of steering wheel 45.

[0076] <Steering Torque Sensor>

[0077] The steering torque sensor 47 is a sensor that detects the torque input to the steering shaft by the driver of the vehicle 100 (the driver of this vehicle) via the steering wheel 45. The steering torque sensor 47 is electrically connected to the ECU 90. The steering torque sensor 47 sends the detected torque-related information to the ECU 90. Based on this information, the ECU 90 obtains the torque input to the steering shaft by the driver via the steering wheel 45 as the driver's input steering torque TQ3drv.

[0078] <Vehicle speed detection device>

[0079] The vehicle speed detection device 48 is a device for detecting the driving speed of the vehicle 100, such as a wheel speed sensor. The vehicle speed detection device 48 is electrically connected to the ECU 90. The vehicle speed detection device 48 sends the detected driving speed information of the vehicle 100 to the ECU 90. Based on this information, the ECU 90 obtains the driving speed of the vehicle 100 as the vehicle speed V1.

[0080] The ECU90 calculates the steering torque that should be output from the steering device 23 based on the steering angle θ, the driver input steering torque TQ3drv, and the vehicle speed V1, and sets it as the required steering torque TQ3req, and outputs the steering torque equivalent to the required steering torque TQ3req from the steering device 23.

[0081] Driving Assist Control Device

[0082] The driving assistance controller 51 is a device operated by the driver of the vehicle, such as a device consisting of switches and buttons. These switches and buttons are, for example, located on the steering wheel 45 or on a stalk mounted on the steering column of the vehicle 100.

[0083] In this example, the driving assistance operator 51 includes a driving assistance selection switch, a vehicle speed setting switch, a vehicle speed increase button, a vehicle speed decrease button, and a vehicle distance setting button. The driving assistance operator 51 is electrically connected to the ECU 90.

[0084] If the driving assistance selection switch is activated when the driving assistance control described later is not executed, a signal will be sent from the driving assistance operator 51 to the ECU 90. Upon receiving this signal, the ECU 90 determines that the execution of driving assistance control has been requested.

[0085] On the other hand, if the driving assistance selection switch is activated while driving assistance control is being executed, a signal is sent from the driving assistance operator 51 to the ECU 90. Upon receiving this signal, the ECU 90 determines that it has stopped requesting the execution of driving assistance control. In other words, the ECU 90 determines that it has requested the termination of driving assistance control.

[0086] Furthermore, if the vehicle speed setting switch is activated when driving assistance control is executed, a signal is sent from the driving assistance operator 51 to the ECU 90. Upon receiving this signal, the ECU 90 sets the vehicle speed V1 at that time as the set speed Vset in the driving assistance control.

[0087] Furthermore, if the speed increase button is pressed while driving assistance control is in operation, a signal is sent from the driving assistance controller 51 to the ECU 90. Upon receiving this signal, the ECU 90 increases the set speed Vset. Conversely, if the speed decrease button is pressed while driving assistance control is in operation, a signal is sent from the driving assistance controller 51 to the ECU 90. Upon receiving this signal, the ECU 90 decreases the set speed Vset.

[0088] Furthermore, if the inter-vehicle distance setting button is operated while driving assistance control is being executed, a signal is sent from driving assistance operator 51 to ECU 90. This signal is a signal (required inter-vehicle distance signal) indicating that the distance (inter-vehicle distance D) between the vehicle 100 and the preceding vehicle 200F in normal following control, as described later, has been requested by the driver of the vehicle by operating the inter-vehicle distance setting button.

[0089] like Figure 2 As shown, the inter-vehicle distance D is the distance between the current vehicle 100 and the preceding vehicle 200F, and is obtained based on the surrounding detection information IS described later. Furthermore, in this example, the preceding vehicle 200 is a vehicle traveling in front of the current vehicle 100 in lane LN (the lane the current vehicle 100 is currently traveling in), and the inter-vehicle distance D is less than a predetermined distance (the preceding vehicle judgment distance Dth). Lane LN is identified based on information related to the left lane line LML and the right lane line LMR of the current vehicle 100 obtained based on the surrounding detection information IS. Furthermore, in this example, the required inter-vehicle distance Dreq, selectable by the driver operating the inter-vehicle distance setting button, is one of three options: slightly longer distance Dlong, medium distance Dmiddle, and slightly shorter distance Dshort.

[0090] When the ECU90 receives a required inter-vehicle distance signal, it can set the set inter-vehicle distance Dset based on the required inter-vehicle distance Dreq, regardless of the vehicle speed V1 at that time. However, in this example, the set inter-vehicle distance Dset is set based on both the vehicle speed V1 at that time and the required inter-vehicle distance Dreq.

[0091] Specifically, the ECU 90 sets the vehicle distance D as the predetermined time (predicted arrival time TTC) obtained by dividing the current vehicle speed V1 at that time point by the vehicle distance V1. That is, the ECU 90 sets the vehicle distance D as the predetermined distance D set when the relationship between the current vehicle speed V1 at that time point, the predetermined predicted arrival time TTCref, and the vehicle distance D is the same as Equation 1.

[0092] TTCref=D / V1…(1)

[0093] The predicted arrival time TTCref is set to a slightly longer time when the required workshop distance Dreq is a slightly longer distance Dlong, a medium time when the required workshop distance Dreq is a medium distance Dmiddle, and a slightly shorter time when the required workshop distance Dreq is a slightly shorter distance Dshort. Additionally, the leading vehicle judgment distance Dth is defined as a distance longer than the set workshop distance Dset.

[0094] <Efficiency-Priority Driving Operator>

[0095] The efficiency-priority driving control 52 is a device operated by the driver of the vehicle, such as a device consisting of switches and buttons. These switches and buttons are, for example, located on the steering wheel 45 of the vehicle 100, or on a rod mounted on the steering column of the vehicle 100.

[0096] If the efficiency-priority driving actuator 52 is operated while it is in the off position, it will become in the on position. When the efficiency-priority driving actuator 52 is operated to the on position, it sends a signal to the ECU 90. Upon receiving this signal, the ECU 90 determines that it has requested the execution of the efficiency-priority auxiliary control described later.

[0097] On the other hand, if the efficiency-priority driving operator 52 is operated while it is in the on position, it will become the off position. When the efficiency-priority driving operator 52 is operated to the off position, it sends a signal to the ECU 90. Upon receiving this signal, the ECU 90 determines that it has stopped requesting the execution of efficiency-priority auxiliary control.

[0098] <Surrounding Information Detection Device>

[0099] The surrounding information detection device 60 is a device for detecting information about the surroundings of the vehicle 100. In this example, it includes an electromagnetic wave sensor 61 and an image sensor 62.

[0100] <Electronic Wave Sensor>

[0101] The radio wave sensor 61 is a sensor that uses radio waves to detect information related to objects present in the vicinity of the vehicle 100. Examples include at least one of acoustic sensors such as radar sensors (millimeter-wave radar, etc.), ultrasonic sensors (gap sonar), and optical sensors such as lidar (LiDAR). The radio wave sensor 61 is electrically connected to the ECU 90. The radio wave sensor 61 transmits radio waves and receives radio waves reflected back by objects (reflected waves). The radio wave sensor 61 transmits information related to the emitted and received radio waves (reflected waves) to the ECU 90. Alternatively, the radio wave sensor 61 detects objects present in the vicinity of the vehicle 100 and transmits information related to the detected objects to the ECU 90. The ECU 90 can obtain information related to objects present in the vicinity of the vehicle 100 based on this information (radio wave information or radio wave data) as perimeter detection information IS. Objects detected using the radio wave sensor 61 include, for example, vehicles, walls, bicycles, and people.

[0102] <Image Sensor>

[0103] Image sensor 62 is a sensor, such as a camera, used to capture images of the surroundings of vehicle 100. Image sensor 62 is electrically connected to ECU 90. Image sensor 62 captures images of the surroundings of vehicle 100 and sends information related to the captured images to ECU 90. ECU 90 can obtain information about the surroundings of vehicle 100 based on this information (image information or image data) as surroundings detection information IS.

[0104] The ECU90 obtains the distance (inter-vehicle distance D) between the preceding vehicle 200F and the current vehicle 100, as well as the speed of the preceding vehicle 200F (preceding speed V2), based on the surrounding detection information IS.

[0105] <Transceiver Device>

[0106] like Figure 3As shown, the transceiver 70 is a device for receiving wireless signals transmitted from vehicles (surrounding vehicles 200S) located in the vicinity of the vehicle 100, or for transmitting wireless signals from the vehicle 100 to the outside, and is electrically connected to the ECU 90. The ECU 90 can obtain wireless signals transmitted from the surrounding vehicles 200S via the transceiver 70, or can transmit wireless signals from the vehicle 100 to the outside via the transceiver 70. The ECU 90 obtains information related to the surrounding vehicles 200S based on the wireless signals transmitted from the surrounding vehicles 200S, and uses this information as inter-vehicle communication information IV.

[0107] <The operation of vehicle driver assistance devices>

[0108] Next, the operation of the vehicle driving assistance device 10 will be described. The vehicle driving assistance device 10 is configured to automatically accelerate or decelerate the vehicle 100 to keep it in motion, even without operation of the accelerator pedal 41 or brake pedal 43 by the driver of the vehicle. In this example, the driving assistance control includes two types of control: normal assistance control and efficiency-priority assistance control.

[0109] <Typical Auxiliary Control>

[0110] Typically, auxiliary control includes two types of control: normal following control (first following control) and normal speed control. While in this example, normal following control is the automatic acceleration / deceleration of the vehicle 100 while maintaining a vehicle distance D at a set vehicle distance Dset (predetermined distance), it can also be the automatic acceleration / deceleration of the vehicle 100 by maintaining the vehicle distance D within a predetermined range (first predetermined distance range) that sets a value greater than a predetermined value of the set vehicle distance Dset as an upper limit and a value less than a predetermined value of the set vehicle distance Dset as a lower limit. On the other hand, normal speed control is the automatic acceleration / deceleration of the vehicle 100 while maintaining the vehicle speed V1 at a set speed Vset.

[0111] <Efficiency-First Auxiliary Control>

[0112] Furthermore, the efficiency-priority auxiliary control automatically accelerates the vehicle 100 through optimal acceleration control when accelerating the vehicle 100, and automatically decelerates the vehicle 100 through inertial driving control when decelerating the vehicle 100. In this example, the efficiency-priority auxiliary control includes three types of control: synchronous action point switching follow-up control (synchronous switching follow-up control, third follow-up control), asynchronous action point switching follow-up control (asynchronous switching follow-up control, second follow-up control), and action point switching constant speed control (switching constant speed control).

[0113] <Optimal Acceleration Control>

[0114] The optimal acceleration control is a control that, taking into account the current vehicle speed, achieves the maximum or approximately maximum energy efficiency of the drive unit 21 to produce the optimal drive torque (optimal drive torque). In other words, it calculates and obtains the minimum or approximately minimum energy consumption of the drive unit 21 to produce the optimal drive torque (optimal drive torque), sets it as the system required drive torque TQ1sys_req, and outputs a drive torque equivalent to the system required drive torque TQ1sys_req from the drive unit 21 to automatically accelerate the vehicle 100.

[0115] That is, in this example, the drive device 21 is composed of a first power source 211 and a second power source 212. Here, the first power source 211 and the second power source 212 have their own different power output characteristics (energy efficiency characteristics when outputting driving force). In this example, the first power source 211 and the second power source 212 have... Figure 4 The power output characteristics are shown. That is, the energy efficiency E of the first power source 211 is highest when the driving torque TQ1 output by the first power source 211 is a certain value TQ1_A, as shown by line Leng, and the energy efficiency E of the second power source 212 is highest when the driving torque TQ1 output by the second power source 212 is a smaller value TQ1_B compared to the above value TQ1_A, as shown by line Lmt.

[0116] Furthermore, when the first power source 211 is an internal combustion engine, the energy efficiency of the first power source 211 corresponds to the so-called fuel consumption rate, and the higher the fuel consumption rate, the higher the energy efficiency. On the other hand, when the second power source 212 is an electric motor, the energy efficiency of the second power source 212 corresponds to the so-called power consumption, and the lower the power consumption, the higher the energy efficiency.

[0117] Thus, the energy efficiency of the drive unit 21 has a characteristic that it reaches a peak (maximum) when the drive torque output by the drive unit 21 is a specific value (optimal drive torque), and there are multiple peaks (two in this example). Therefore, if the optimal drive torque is output from the drive unit 21 to accelerate the vehicle 100, the energy efficiency of the drive unit 21 will increase. That is, the energy consumption of the drive unit 21 will decrease.

[0118] Thus, optimal acceleration control is the control that automatically accelerates the vehicle 100 by outputting a drive torque equivalent to the optimal drive torque from the drive unit 21. In other words, optimal acceleration control is the control that automatically accelerates the vehicle 100 by operating the drive unit 21 with minimal energy consumption.

[0119] Alternatively, optimal acceleration control can also involve calculating a drive torque that is slightly larger or slightly smaller than the optimal drive torque and setting it as the system required drive torque TQ1sys_req, then outputting a drive torque equivalent to the system required drive torque TQ1sys_req from the drive unit 21 to automatically accelerate the vehicle 100. That is, optimal acceleration control can also involve operating the drive unit 21 with an optimal energy consumption level, including "minimum energy consumption and slightly larger than that," to automatically accelerate the vehicle 100. In other words, optimal acceleration control can also involve operating the drive unit 21 with its energy consumption below a predetermined amount to automatically accelerate the vehicle 100.

[0120] <Inertial Driving Control>

[0121] On the other hand, inertial driving control is a control that outputs a driving torque from the drive unit 21 such that the vehicle 100 neither accelerates nor decelerates, thereby enabling the vehicle 100 to perform inertial driving. In this example, inertial driving control is a control that outputs a driving torque from the second power source 212 in a manner that stops the operation of the first power source 211 (e.g., an internal combustion engine) and maximizes the energy efficiency of the second power source 212 (e.g., an electric motor), thereby enabling the vehicle 100 to perform inertial driving. Accordingly, the vehicle 100 decelerates primarily due to its driving resistance.

[0122] <Synchronous Switching Follower Control (Third Follower Control)>

[0123] The synchronous switching follow control is to synchronize (or approximately synchronize) the acceleration and deceleration of the preceding vehicle 200F, which is the vehicle 200E being synchronized with, by following the preceding vehicle 200F which is using the same efficiency priority assist control as in this example (i.e., control to accelerate and decelerate the vehicle through optimal acceleration control and inertial driving control), thereby automatically controlling the acceleration and deceleration of the vehicle 100 through optimal acceleration control and inertial driving control.

[0124] The synchronization target vehicle 200E is a vehicle surrounding the vehicle 100 (surrounding vehicle 200S), and is a vehicle that has a drive device with the same or approximately the same power output characteristics as the drive device 21 of the vehicle 100.

[0125] In addition, in this example, information related to the control performed on the drive unit of the surrounding vehicle 200S is included in the inter-vehicle communication information IV. Therefore, the vehicle driving assistance device 10 determines whether the surrounding vehicle 200S is driving through efficiency priority assistance control based on the inter-vehicle communication information IV.

[0126] Furthermore, in this example, information related to the power output characteristics of the drive unit of the surrounding vehicle 200S is also included in the vehicle-to-vehicle communication information IV. Therefore, the vehicle driving assistance device 10 determines, based on the vehicle-to-vehicle communication information IV, whether the difference between the optimal drive torque of the drive unit of the surrounding vehicle 200S and the optimal drive torque of the drive unit 21 of the vehicle 100 is below a predetermined value (in this example, whether the power output characteristics of the drive unit of the surrounding vehicle 200S are the same or approximately the same as the power output characteristics of the drive unit 21 of the vehicle 100).

[0127] Furthermore, there are cases where information related to the control being performed on the drive unit of the surrounding vehicle 200S is not included in the vehicle-to-vehicle communication information IV. In this case, the vehicle driving assistance device 10 obtains the drive torque output from the drive unit of the surrounding vehicle 200S (the drive torque of the surrounding vehicle 200S) based on the surrounding detection information IS, and determines whether the surrounding vehicle 200S is driving under efficiency priority assist control based on the drive torque.

[0128] More specifically, the vehicle driving assistance device 10 obtains the peak value of the acceleration of the surrounding vehicle 200S based on the surrounding detection information IS (peak acceleration of the surrounding vehicle 200S), and when the peak acceleration is summarized into two specific values, it determines that the surrounding vehicle 200S is driving through efficiency priority assistance control.

[0129] Furthermore, there are cases where information concerning the power output characteristics of the drive unit of the surrounding vehicle 200S is not included in the vehicle-to-vehicle communication information IV. In this case, the vehicle driving assistance device 10 obtains the drive torque of the surrounding vehicle 200S based on the surrounding detection information IS, and determines, based on the drive torque, whether the difference between the optimal drive torque of the surrounding vehicle 200S and the optimal drive torque of the vehicle 100 is below a predetermined value (i.e., whether the power output characteristics of the drive unit of the surrounding vehicle 200S are the same as or approximately the same as the power output characteristics of the drive unit 21 of the vehicle 100).

[0130] More specifically, the vehicle driving assistance device 10 obtains the peak acceleration of the surrounding vehicle 200S based on the surrounding detection information IS, and if the difference between the peak acceleration and the peak value of the acceleration of the vehicle 100 achieved by the drive device 21 (the peak acceleration of the vehicle 100) is below a predetermined value, it determines that the difference between the optimal drive torque of the drive device of the surrounding vehicle 200S and the optimal drive torque of the drive device 21 of the vehicle 100 is below a predetermined value (that is, the power output characteristics of the drive device of the surrounding vehicle 200S are the same as or approximately the same as the power output characteristics of the drive device 21 of the vehicle 100).

[0131] In this example, the vehicle driving assistance device 10 obtains the peak acceleration of the surrounding vehicle 200S based on the surrounding detection information IS. When the difference between the peak acceleration and the peak acceleration of the vehicle 100 is zero, it is determined that the power output characteristics of the drive device of the surrounding vehicle 200S are the same as the power output characteristics of the drive device 21 of the vehicle 100. When the difference between the peak acceleration of the surrounding vehicle 200S and the peak acceleration of the vehicle 100 is greater than zero but less than a predetermined value, it is determined that the power output characteristics of the drive device of the surrounding vehicle 200S are approximately the same as the power output characteristics of the drive device 21 of the vehicle 100.

[0132] <Asynchronous Switching Follower Control (Second Follower Control)>

[0133] The asynchronous switching follow control is to automatically control the acceleration and deceleration of the vehicle 100 at predetermined times by following the preceding vehicle 200F, which is not a synchronized target vehicle 200E, or the preceding vehicle 200F, which is a synchronized target vehicle 200E but is not currently using efficiency priority auxiliary control.

[0134] <Switching to constant speed control>

[0135] Furthermore, the switch to cruise control means that the vehicle 100 is automatically accelerated or decelerated at predetermined times by means of optimal acceleration control and inertial driving control, in a manner that maintains the vehicle speed within a predetermined range.

[0136] <The specific operation of vehicle driving assistance devices>

[0137] The following is for reference Figures 5 to 14 The routines shown will be described in more detail, along with various controls performed by the vehicle driving assistance device 10, including general assistance control and efficiency-priority assistance control.

[0138] The vehicle driving assistance device 10 executes according to a predetermined calculation cycle. Figure 5The routine is shown. Therefore, when the predetermined moment arrives, the vehicle driving assistance device 10 starts from... Figure 5 The routine shown begins processing at step 500 and proceeds to step 505.

[0139] The vehicle driving assistance device 10 performs driving assistance control when the driving assistance request condition C1 is met, and performs normal driving control when the driving assistance request condition C1 is not met. Therefore, when the process enters step 505, the vehicle driving assistance device 10 determines whether the driving assistance request condition C1 has been met.

[0140] Although the vehicle driving assistance device 10 can also be configured such that when the driving assistance operator 51 is operated and the execution of driving assistance control is requested, the driving assistance request condition C1 is determined to be met regardless of whether the accelerator pedal 41 or the brake pedal 43 is operated, in this example, the driving assistance request condition C1 is determined to be met when neither the accelerator pedal 41 nor the brake pedal 43 is operated when the execution of driving assistance control is requested.

[0141] Furthermore, if the driving assistance device 10 requests the termination of driving assistance control by operating the driving assistance operator 51 during the execution of driving assistance control, it determines that the driving assistance request condition C1 is no longer valid; that is, it determines that the condition for terminating driving assistance control (driving assistance termination condition) has been met. Additionally, if the brake pedal 43 is operated during the execution of driving assistance control, i.e., if the brake pedal operation amount BP becomes greater than zero, it also determines that the driving assistance request condition C1 is no longer valid; that is, it determines that the driving assistance termination condition has been met. When the driving assistance request condition C1 is no longer valid, the driving assistance device 10 terminates driving assistance control and executes the normal driving control described later.

[0142] If the driving assistance request condition C1 is not met, the vehicle driving assistance device 10 determines "no" in step 505 and proceeds to step 550, performing normal driving control. Afterwards, the vehicle driving assistance device 10 temporarily terminates the processing of this routine.

[0143] Normal driving control involves calculating the drive torque that should be output from the drive unit 21 based on the accelerator pedal operation amount AP and the vehicle speed V1, setting it as the driver's required drive torque TQ1drv_req, and outputting a drive torque equivalent to the driver's required drive torque TQ1drv_req from the drive unit 21. Additionally, calculating the braking torque that should be applied to the vehicle 100 by the braking device 22 based on the brake pedal operation amount BP, setting it as the driver's required braking torque TQ2drv_req, and applying a braking torque equivalent to the driver's required braking torque TQ2drv_req to the vehicle 100 via the braking device 22.

[0144] Furthermore, the vehicle driving assistance device 10 is configured such that, during the execution of normal driving control, when the driver's required driving torque TQ1drv_req is larger than a value greater than zero (operation switching threshold TQ1th), the driving torque equivalent to the driver's required driving torque TQ1drv_req is output from the drive device 21 by outputting driving torque from both the first power source 211 and the second power source 212; and when the driver's required driving torque TQ1drv_req is below the operation switching threshold TQ1th, the operation of the first power source 211 is stopped and the driving torque is output only from the second power source 212, thereby outputting the driving torque equivalent to the driver's required driving torque TQ1drv_req from the drive device 21.

[0145] On the other hand, if the driving assistance request condition C1 has been met, the vehicle driving assistance device 10 determines "yes" in step 505 and causes the process to proceed to step 510.

[0146] The vehicle driving assistance device 10 performs efficiency-priority assistance control when the efficiency-priority request condition C2 is met, and performs normal assistance control when the efficiency-priority request condition C2 is not met. Therefore, when the process enters step 510, the vehicle driving assistance device 10 determines whether the efficiency-priority request condition C2 has been met. If the efficiency-priority driving operator 52 is operated and requests the execution of efficiency-priority assistance control, the vehicle driving assistance device 10 determines that the efficiency-priority request condition C2 has been met.

[0147] If the efficiency priority request condition C2 is not met, the vehicle driving assistance device 10 determines "no" in step 510 and proceeds to step 545, through execution. Figure 12 The routine shown performs normal auxiliary control. Therefore, when the process enters step 545, the vehicle driving assistance device 10... Figure 12The routine shown begins processing at step 1200 and proceeds to step 1205.

[0148] When a preceding vehicle 200F is present, the vehicle driving assistance device 10 performs normal following control as a normal assistance control, and when a preceding vehicle 200F is not present, it performs normal cruise control as a normal assistance control. Therefore, when the process proceeds to step 1205, the vehicle driving assistance device 10 determines whether a preceding vehicle 200F is present.

[0149] If a preceding vehicle 200F is present, the vehicle driving assistance device 10 determines "yes" in step 1205 and initiates the process in step 1210, by executing... Figure 13 The routine shown performs the usual follow control. Therefore, when the process enters step 1210, the vehicle driving assistance device 10... Figure 13 The routine shown begins processing at step 1300 and proceeds to step 1305.

[0150] As previously described, the normal following control is a control that automatically accelerates or decelerates the vehicle 100 while maintaining the inter-vehicle distance D at a set inter-vehicle distance Dset. More specifically, in this example, the normal following control is a control that automatically accelerates or decelerates the vehicle 100 while maintaining the predicted arrival time TTC at a predetermined predicted arrival time TTCref. Therefore, the vehicle driving assistance device 10 accelerates the vehicle 100 when the predicted arrival time TTC is longer than the predetermined predicted arrival time TTCref (when the normal following acceleration condition C3 is met), and decelerates the vehicle 100 when the predicted arrival time TTC is shorter than the predetermined predicted arrival time TTCref (when the normal following deceleration condition C4 is met).

[0151] Therefore, when the process proceeds to step 1305, the vehicle driving assistance device 10 determines whether the normal following acceleration condition C3 has been met. If the normal following acceleration condition C3 has been met, the vehicle driving assistance device 10 determines "yes" in step 1305 and proceeds to step 1310, thereby executing normal following acceleration control.

[0152] Typically, the following acceleration control is to calculate the drive torque that should be output from the drive unit 21 so that the predicted arrival time TTC converges to the predetermined predicted arrival time TTCref, and set it as the system demand drive torque TQ1sys_req, and control the drive torque equivalent to the system demand drive torque TQ1sys_req to be output from the drive unit 21.

[0153] After performing the processing in step 1310, the vehicle driving assistance device 10 temporarily terminates the processing of this routine.

[0154] On the other hand, if the normal following acceleration condition C3 is not met, the vehicle driving assistance device 10 determines "no" in step 1305 and proceeds to step 1315 to determine whether the normal following deceleration condition C4 has been met. If the normal following deceleration condition C4 has been met, the vehicle driving assistance device 10 determines "yes" in step 1315 and proceeds to step 1320, thereby performing normal following deceleration control.

[0155] Typically, the following deceleration control involves calculating the drive torque that should be output from the drive unit 21 to make the predicted arrival time TTC converge to the predetermined predicted arrival time TTCref, and setting this as the system required drive torque TQ1sys_req. It also calculates the braking torque that should be applied to the vehicle 100 by the braking device 22 and sets this as the system required braking torque TQ2sys_req. The drive torque equivalent to the system required drive torque TQ1sys_req is output from the drive unit 21, and the braking torque equivalent to the system required braking torque TQ2sys_req is applied to the vehicle 100 through the braking device 22.

[0156] After performing the processing in step 1320, the vehicle driving assistance device 10 temporarily terminates the processing of this routine.

[0157] On the other hand, if the normal following deceleration condition C4 is not met, the vehicle driving assistance device 10 determines "no" in step 1315 and causes the processing to proceed to step 1325, thereby executing constant speed driving control.

[0158] Constant speed driving control is a control that obtains the driving torque used to maintain the vehicle speed at that time point through calculation, sets it as the system demand driving torque TQ1sys_req, and outputs the system demand driving torque TQ1sys_req from the drive unit 21.

[0159] After performing the processing in step 1325, the vehicle driving assistance device 10 temporarily terminates the processing of this routine.

[0160] Furthermore, during the execution of normal following control, if the accelerator pedal 41 is depressed and the driver's required drive torque TQ1drv_req is greater than the system's required drive torque TQ1sys_req, the vehicle driving assistance device 10 determines that an accelerator override state (driver override state) has occurred and interrupts normal following control, and outputs a drive torque equivalent to the driver's required drive torque TQ1drv_req from the drive unit 21. That is, the vehicle driving assistance device 10 interrupts normal following control and executes normal driving control. Subsequently, if the accelerator pedal 41 is depressed and the driver's required drive torque TQ1drv_req becomes less than or equal to the system's required drive torque TQ1sys_req, the vehicle driving assistance device 10 resumes normal following control.

[0161] On the other hand, the vehicle driving assistance device 10 is in Figure 12 In the example shown, if there is no preceding vehicle 200F at the execution time of step 1205, the process is judged as "no" in step 1205, and the process proceeds to step 1215. Figure 14 The routine shown performs normal cruise control. Therefore, when the vehicle driving assistance device 10 causes the processing to proceed to step 1215, from Figure 14 The routine shown begins processing at step 1400 and proceeds to step 1405.

[0162] As previously described, cruise control typically involves automatically accelerating or decelerating the vehicle 100 while maintaining its current speed V1 at a set speed Vset. Therefore, when the vehicle speed V1 falls below the set speed Vset (when the cruise acceleration condition C5 is met), the vehicle driver assistance device 10 accelerates the vehicle 100, and when the vehicle speed V1 falls above the set speed Vset (when the cruise deceleration condition C6 is met), it decelerates the vehicle 100.

[0163] Therefore, when the process proceeds to step 1405, the vehicle driving assistance device 10 determines whether the normal constant speed acceleration condition C5 has been met. If the normal constant speed acceleration condition C5 has been met, the vehicle driving assistance device 10 determines "yes" in step 1405 and proceeds to step 1410, thereby executing normal constant speed acceleration control.

[0164] Typically, constant speed acceleration control involves calculating the drive torque that should be output from the drive unit 21 to make the vehicle speed V1 converge to the set speed Vset, setting it as the system required drive torque TQ1sys_req, and controlling the output of the drive torque equivalent to the system required drive torque TQ1sys_req from the drive unit 21.

[0165] After performing the processing in step 1410, the vehicle driving assistance device 10 temporarily terminates the processing of this routine.

[0166] On the other hand, if the normal constant speed acceleration condition C5 is not met, the vehicle driving assistance device 10 determines "no" in step 1405 and proceeds to step 1415 to determine whether the normal constant speed deceleration condition C6 has been met. If the normal constant speed deceleration condition C6 has been met, the vehicle driving assistance device 10 determines "yes" in step 1415 and proceeds to step 1420, thereby performing normal constant speed deceleration control.

[0167] Typically, constant speed deceleration control involves calculating the drive torque that should be output from the drive unit 21 to make the vehicle speed V1 converge to the set speed Vset, setting this as the system required drive torque TQ1sys_req, calculating the braking torque that should be applied to the vehicle 100 by the braking device 22, setting this as the system required braking torque TQ2sys_req, outputting the drive torque equivalent to the system required drive torque TQ1sys_req from the drive unit 21, and applying the braking torque equivalent to the system required braking torque TQ2sys_req to the vehicle 100 through the braking device 22.

[0168] After performing the processing in step 1420, the vehicle driving assistance device 10 temporarily terminates the processing of this routine.

[0169] On the other hand, if the normal constant speed deceleration condition C6 is not met, the vehicle driving assistance device 10 determines "no" in step 1415 and proceeds to step 1425, thereby executing constant speed driving control. Afterwards, the vehicle driving assistance device 10 temporarily terminates the processing of this routine.

[0170] Furthermore, during the execution of normal cruise control, if the accelerator pedal 41 is depressed and the driver's required drive torque TQ1drv_req becomes greater than the system's required drive torque TQ1sys_req, the vehicle driving assistance device 10 also determines that an accelerator overrun has occurred and interrupts normal cruise control, and outputs a drive torque equivalent to the driver's required drive torque TQ1drv_req from the drive unit 21. That is, the vehicle driving assistance device 10 interrupts normal cruise control and executes normal driving control. Subsequently, if the accelerator pedal 41 is depressed and the driver's required drive torque TQ1drv_req becomes less than the system's required drive torque TQ1sys_req, the vehicle driving assistance device 10 resumes normal cruise control.

[0171] On the other hand, the vehicle driving assistance device 10 in Figure 5 If the efficiency priority request condition C2 for the processing of step 510 of the routine shown has been met, the vehicle driving assistance device 10 determines "yes" in step 510 and proceeds to step 515.

[0172] When a synchronization target vehicle 200E exists and is traveling under efficiency-priority assist control (i.e., the synchronization condition is met), the vehicle driving assistance device 10 performs synchronization switching follow-up control. Conversely, if no synchronization target vehicle 200E exists, or if a synchronization target vehicle 200E exists but is not traveling under efficiency-priority assist control, the vehicle driving assistance device 10 performs asynchronous switching follow-up control or speed control switching based on the presence or absence of the preceding vehicle 200F. Therefore, when the process proceeds to step 515, the vehicle driving assistance device 10 determines whether a synchronization target vehicle 200E exists.

[0173] If a synchronization target vehicle 200E exists, the vehicle driving assistance device 10 determines "yes" in step 515 and proceeds to step 520 to determine whether the synchronization target vehicle 200E is currently driving under efficiency-priority assist control. If the synchronization target vehicle 200E is currently driving under efficiency-priority assist control, the vehicle driving assistance device 10 determines "yes" in step 520 and proceeds to step 525, by executing... Figure 6 or Figure 7 The example shown performs synchronous switching follow control.

[0174] Therefore, the vehicle driving assistance device 10 will execute when the process enters step 525. Figure 6 In the case of the routine shown, when the process enters step 525, from Figure 6The routine shown begins processing at step 600 and proceeds to step 605.

[0175] Although the vehicle driving assistance device 10 performs acceleration and deceleration of its own vehicle 100 by optimal acceleration control and inertial driving control when the synchronized target vehicle 200E (which is traveling under efficiency priority assistance control) is the preceding vehicle 200F (if control execution condition C7 has been met), if control execution condition C7 has not been met, it performs acceleration and deceleration of its own vehicle 100 by optimal acceleration control and inertial driving control after moving its own vehicle 100 behind the synchronized target vehicle 200E (other vehicles).

[0176] Therefore, when the vehicle driving assistance device 10 proceeds to step 605, it determines whether the control execution condition C7 has been met. If the control execution condition C7 has not been met, the vehicle driving assistance device 10 determines "no" in step 605 and proceeds to step 630, thereby executing the vehicle movement control. The vehicle movement control is the control that moves the vehicle 100 behind the synchronous target vehicle 200E. After the execution of the process in step 630, the vehicle driving assistance device 10 temporarily terminates the processing of this routine.

[0177] On the other hand, if the control execution condition C7 has been met, the vehicle driving assistance device 10 determines "yes" in step 605 and causes the process to proceed to step 610.

[0178] Furthermore, although in this example the vehicle driving assistance device 10 is configured to move the vehicle 100 behind the synchronized target vehicle 200E when the synchronized target vehicle 200E traveling under efficiency priority assistance control is not the leading vehicle 200F, it can also be configured to notify the driver of the presence of a synchronized target vehicle 200E traveling under efficiency priority assistance control using a display or speaker, or to suggest to the driver that such a synchronized target vehicle 200E be set as the target vehicle for the vehicle 100 to follow using a display or speaker.

[0179] As previously described, the synchronized switching follow control involves synchronizing (or approximately synchronizing) the acceleration and deceleration of the preceding vehicle 200F, which is the vehicle being synchronized with the vehicle 200E and is traveling via efficiency-priority auxiliary control, with the preceding vehicle 200F. This is achieved through optimal acceleration control and inertial driving control, thereby automatically accelerating and decelerating the vehicle 100. Therefore, when the preceding vehicle 200F is accelerating via optimal acceleration control, the vehicle driving assistance device 10 accelerates the vehicle 100 via optimal acceleration control; and when the preceding vehicle 200F is decelerating via inertial driving control, the vehicle 100 decelerates via inertial driving control.

[0180] Therefore, when the process proceeds to step 610, the vehicle driving assistance device 10 determines whether there is information indicating that the preceding vehicle 200F has accelerated based on the vehicle-to-vehicle communication information IV. If there is information indicating that the preceding vehicle 200F has accelerated, the vehicle driving assistance device 10 determines "yes" in step 610 and proceeds to step 615, thereby executing optimal acceleration control. Afterward, the vehicle driving assistance device 10 temporarily terminates the processing of this routine.

[0181] On the other hand, if there is no information indicating that the preceding vehicle 200F has accelerated, the vehicle driving assistance device 10 determines "no" in step 610 and proceeds to step 620, and determines whether there is information indicating that the preceding vehicle 200F has decelerated based on the vehicle-to-vehicle communication information IV. If there is information indicating that the preceding vehicle 200F has decelerated, the vehicle driving assistance device 10 determines "yes" in step 620 and proceeds to step 625, thereby performing inertial driving control. Afterwards, the vehicle driving assistance device 10 temporarily terminates the processing of this routine.

[0182] On the other hand, if there is no information indicating that the preceding vehicle 200F has decelerated, the vehicle driving assistance device 10 determines "no" in step 620 and temporarily terminates the processing of this routine. In this case, if the vehicle driving assistance device 10 is performing optimal acceleration control at that time, it continues to perform optimal acceleration control; if it is performing inertial driving control at that time, it continues to perform inertial driving control.

[0183] Alternatively, it will be executed when the process proceeds to step 525. Figure 7 In the example shown, when the process enters step 525, the vehicle driving assistance device 10 from Figure 7 The routine shown begins processing from step 700 and proceeds to step 705, whereby it is determined whether the control execution condition C7 has been met.

[0184] If the control execution condition C7 is not met, the vehicle driving assistance device 10 determines "no" in step 705 and proceeds to step 730, thereby executing vehicle movement control. Afterwards, the vehicle driving assistance device 10 temporarily terminates the processing of this routine.

[0185] On the other hand, if the control execution condition C7 is met, the vehicle driving assistance device 10 determines "yes" in step 705 and proceeds to step 710, and determines whether the preceding vehicle 200F has accelerated based on the surrounding detection information IS. If the preceding vehicle 200F has accelerated, the vehicle driving assistance device 10 determines "yes" in step 710 and proceeds to step 715, thereby executing optimal acceleration control. Afterwards, the vehicle driving assistance device 10 temporarily terminates the processing of this routine.

[0186] On the other hand, if the preceding vehicle 200F does not accelerate, the vehicle driving assistance device 10 determines "no" in step 710 and proceeds to step 720, and determines whether the preceding vehicle 200F has decelerated based on the surrounding detection information IS. If the preceding vehicle 200F has decelerated, the vehicle driving assistance device 10 determines "yes" in step 720 and proceeds to step 725, thereby executing inertial driving control. Afterwards, the vehicle driving assistance device 10 temporarily terminates the processing of this routine.

[0187] On the other hand, if the preceding vehicle 200F does not decelerate, the vehicle driving assistance device 10 determines "no" in step 720 and temporarily terminates the processing of this routine. In this case, if the vehicle driving assistance device 10 is performing optimal acceleration control at that time, it continues to perform optimal acceleration control; if it is performing inertial driving control at that time, it continues to perform inertial driving control.

[0188] Furthermore, if a leading vehicle 200F exists but is not the synchronization target vehicle 200E, or if the leading vehicle 200F is the synchronization target vehicle 200E but is not currently traveling under efficiency priority assist control, the vehicle driving assistance device 10 does not perform synchronization switching follow control. In this case, although there is an option to perform normal follow control, since normal follow control does not use optimal acceleration control and inertial driving control for the acceleration and deceleration of the vehicle 100, the energy efficiency of the drive unit 21 for the acceleration and deceleration of the vehicle 100 is lower compared to the case where optimal acceleration control and inertial driving control are used to accelerate and decelerate the vehicle 100.

[0189] However, on the other hand, when the vehicle 100 is accelerated or decelerated using optimal acceleration control and inertial driving control, the inter-vehicle distance D will increase or decrease. Therefore, compared with the case where normal following control is performed, there is a possibility that the energy efficiency improvement effect (air resistance reduction effect) of the drive unit 21 caused by the reduction of air resistance of the vehicle 100 will be smaller.

[0190] Thus, when comparing the situation where the vehicle 100 is driven by normal following control and the situation where the vehicle 100 is driven by optimal acceleration control and inertial driving control, although a certain reduction in air resistance can be achieved when the vehicle 100 is driven by normal following control, the energy efficiency of the drive unit 21 for the acceleration and deceleration of the vehicle 100 is relatively small. On the other hand, when the vehicle 100 is driven by optimal acceleration control and inertial driving control, although the energy efficiency of the drive unit 21 for the acceleration and deceleration of the vehicle 100 is relatively large, there is a possibility that the effect of reducing air resistance is smaller.

[0191] Therefore, when there is no synchronized target vehicle 200E, or when there is synchronized target vehicle 200E but the synchronized target vehicle 200E is not driving under efficiency priority assist control, the vehicle driving assistance device 10 decides whether to perform asynchronous switching follow control or normal follow control based on the presence or absence of the preceding vehicle 200F, and performs switching cruise control when there is no preceding vehicle 200F.

[0192] That is, the vehicle driving assistance device 10 is in Figure 5 If there is no synchronized target vehicle 200E at the execution time of step 515 of the routine shown, the result in step 515 is "no" and the process proceeds to step 530, where a determination is made as to whether there is a preceding vehicle 200F.

[0193] In addition, the vehicle driving assistance device 10 Figure 5 If the synchronization target vehicle 200E is not traveling under efficiency priority auxiliary control at the execution time of step 520 of the routine shown, the result in step 520 is "no" and the process proceeds to step 530, where a determination is made as to whether there is a preceding vehicle 200F.

[0194] If there is no preceding vehicle 200F, the vehicle driving assistance device 10 determines "no" in step 530 and proceeds to step 540, and executes... Figure 11 The routine shown performs the switching of cruise control. Therefore, when the process enters step 540, the vehicle driving assistance device 10... Figure 11The routine shown begins processing at step 1100 and proceeds to step 1105.

[0195] As previously described, the cruise control switching involves controlling the vehicle 100 to accelerate or decelerate at predetermined times by means of optimal acceleration control and inertial driving control, while maintaining the vehicle speed V1 within a predetermined range. More specifically, in this example, the cruise control switching involves automatically accelerating or decelerating the vehicle 100 by means of optimal acceleration control and inertial driving control, while maintaining the vehicle speed V1 within the set speed range RVset, with a certain range centered on a set speed Vset as the set speed range Rvset. Therefore, when the vehicle speed becomes slower than the lower limit of the set speed range Rvset (when the cruise control acceleration condition C8 is met), the vehicle driving assistance device 10 accelerates the vehicle 100 by means of optimal acceleration control, and when the vehicle speed becomes faster than the upper limit of the set speed range Rvset (when the cruise control deceleration condition C9 is met), the vehicle decelerates the vehicle 100 by means of inertial driving control.

[0196] Therefore, when the process proceeds to step 1105, the vehicle driving assistance device 10 determines whether the constant speed acceleration switching condition C8 has been met. If the constant speed acceleration switching condition C8 has been met, the vehicle driving assistance device 10 determines "yes" in step 1105 and proceeds to step 1110, thereby executing optimal acceleration control. Afterward, the vehicle driving assistance device 10 temporarily terminates the processing of this routine.

[0197] On the other hand, if the constant speed acceleration switching condition C8 is not met, the vehicle driving assistance device 10 determines "no" in step 1105 and proceeds to step 1115, and determines whether the constant speed deceleration switching condition C9 is met. If the constant speed deceleration switching condition C9 is met, the vehicle driving assistance device 10 determines "yes" in step 1115 and proceeds to step 1120, thereby executing inertial driving control. Afterwards, the vehicle driving assistance device 10 temporarily terminates the processing of this routine.

[0198] On the other hand, if the constant speed deceleration condition C9 is not met, the vehicle driving assistance device 10 determines "no" in step 1115 and temporarily terminates the processing of this routine. In this case, if the vehicle driving assistance device 10 is performing optimal acceleration control at that time, it continues to perform optimal acceleration control; if it is performing inertial driving control at that time, it continues to perform inertial driving control.

[0199] On the other hand, the vehicle driving assistance device 10 in Figure 5In the example shown, if there is a preceding vehicle 200F at the execution time of step 530, step 530 determines "yes" and proceeds to step 535, whereby execution continues. Figure 8 The routine shown. Therefore, when the process enters step 535, the vehicle driving assistance device 10 from Figure 8 The routine shown begins processing from step 800.

[0200] The vehicle driving assistance device 10 performs asynchronous switching follow control when the energy consumption of the drive unit 21 that drives the vehicle 100 through asynchronous switching follow control is lower than that when the vehicle 100 is driven through normal follow control, and performs normal follow control when the energy consumption of the drive unit 21 that drives the vehicle 100 through asynchronous switching follow control is higher than that when the vehicle 100 is driven through normal follow control.

[0201] Therefore, the vehicle driving assistance device 10 obtains the energy consumption of the drive unit 21 when the vehicle 100 is driven by normal follow control (first energy consumption EN1) and the energy consumption of the drive unit 21 when the vehicle 100 is driven by asynchronous switching follow control (second energy consumption EN2) in the following manner.

[0202] That is, the energy consumption of the drive unit 21 reduced due to the decrease in air resistance of the vehicle 100 caused by the vehicle 100 following the preceding vehicle 200F (following travel reduction ΔENacc) varies depending on the category of the preceding vehicle 200F (especially the size of the preceding vehicle 200F's body). Generally, the larger the body of the preceding vehicle 200F, the smaller the air resistance of the vehicle 100. Therefore, the vehicle driving assistance device 10 obtains the category of the preceding vehicle 200F based on the surrounding detection information IS and / or the vehicle-to-vehicle communication information IV.

[0203] Furthermore, the following distance reduction ΔENacc varies depending on the inter-vehicle distance D and the vehicle speed V1. Generally, the shorter the inter-vehicle distance D, the lower the air resistance of the vehicle 100, and the lower the vehicle speed V1, the lower the air resistance of the vehicle 100. Therefore, the vehicle driving assistance device 10 predicts the future leading vehicle speed V2 based on the change history of the leading vehicle speed V2 obtained and pre-stored based on the surrounding detection information IS and / or the vehicle-to-vehicle communication information IV, and predicts the inter-vehicle distance D and the vehicle speed V1 when the vehicle 100 follows the leading vehicle 200F traveling at the predicted leading vehicle speed V2 (predicted leading vehicle speed V2pre) through normal following control.

[0204] Furthermore, the vehicle driving assistance device 10 calculates the energy consumption of the drive unit 21 when the vehicle 100 is driven by normal following control based on the category of the preceding vehicle 200F, the predicted inter-vehicle distance D, and the vehicle speed V1, and sets the energy consumption as the first energy consumption EN1.

[0205] Additionally, in this example, such as Figure 15 As shown, since the vehicle driving assistance device 10 pre-stores a mapping (lookup table) for obtaining the energy consumption of the drive unit 21 based on the inter-vehicle distance D and the vehicle speed V1 according to each category of the preceding vehicle 200F, when obtaining the energy consumption of the drive unit 21 when the vehicle 100 is driven using normal following control, by selecting the mapping corresponding to the category of the preceding vehicle 200F and accumulating the energy consumption obtained by applying the inter-vehicle distance D and the vehicle speed V1 predicted as described above in the mapping, the energy consumption of the drive unit 21 when the vehicle 100 is driven using normal following control is obtained.

[0206] On the other hand, although the vehicle 100 is driven by asynchronous switching follow control, the inter-vehicle distance D and the vehicle speed V1 will increase or decrease significantly compared to the case where the vehicle 100 is driven by normal follow control, if the inter-vehicle distance D becomes too large or the vehicle speed V1 becomes too small, it may cause traffic congestion, which is not preferable. Therefore, it is preferable that when the vehicle 100 is driven by asynchronous switching follow control, the inter-vehicle distance D is not greater than the maximum allowable distance (maximum allowable distance Dmax), or the vehicle speed V1 is not less than the minimum allowable speed (minimum allowable speed Vmin).

[0207] Furthermore, it is not preferable from the viewpoint of ensuring the driving safety of the vehicle 100 if the inter-vehicle distance D becomes too small or the vehicle speed V1 becomes too large. Moreover, the vehicle speed V1 should be limited to a range not exceeding the speed specified in traffic regulations. Therefore, it is preferable that, when the vehicle 100 is driven by asynchronous switching follow control, the inter-vehicle distance D is not less than the minimum allowable distance (minimum allowable distance Dmin), or the vehicle speed V1 is not greater than the maximum allowable speed (maximum allowable speed Vmax), when the vehicle 100 is driven by asynchronous switching follow control.

[0208] Based on the above, such as Figure 16As shown, the vehicle driving assistance device 10 sets a maximum permissible distance Dmax and a minimum permissible distance Dmin, and sets the range between these maximum permissible distances Dmax and minimum permissible distances Dmin as the permissible distance range RDpmt (second predetermined distance range). It also sets a maximum permissible speed Vmax and a minimum permissible speed Vmin, and sets the range between these maximum permissible speeds Vmax and minimum permissible speeds Vmin as the permissible speed range RVpmt (predetermined speed range).

[0209] Furthermore, as previously described, in the case where the vehicle 100 is automatically accelerated or decelerated in a manner where the normal following control is such that the inter-vehicle distance D is maintained within a predetermined range (first predetermined distance range), the allowable distance range RDpmt (second predetermined distance range) is set to be a larger range compared to the predetermined range (first predetermined distance range) in the normal following control.

[0210] Furthermore, generally, the maximum permissible distance Dmax is smaller on ordinary roads than on highways, and the minimum permissible speed Vmin is smaller on ordinary roads than on highways. Therefore, it is preferable that the permissible distance range RDpmt and the permissible speed range RVpmt are set according to the driving environment, such as the type of road on which the vehicle 100 is traveling. Thus, in this example, the vehicle driving assistance device 10 sets the maximum permissible distance Dmax, the minimum permissible distance Dmin, the maximum permissible speed Vmax, and the minimum permissible speed Vmin according to the driving environment of the vehicle 100, and sets the permissible distance range RDpmt and the permissible speed range RVpmt. Alternatively, the maximum permissible distance Dmax can also be set according to the driving environment of the vehicle 100 and the required inter-vehicle distance Dreq. In this case, the longer the required inter-vehicle distance Dreq, the longer the maximum permissible distance Dmax is set.

[0211] Furthermore, when the vehicle driving assistance device 10 drives relative to the lead vehicle 200F which is driving at the predicted lead vehicle speed V2 (predicted lead vehicle speed V2pre) as described above, under the condition that the vehicle distance D is maintained within the allowable distance range RDpmt and the vehicle speed V1 is maintained within the allowable speed range RVpmt, the device obtains the acceleration start speed Vacc (the threshold of the vehicle speed V1 at which optimal acceleration control begins), acceleration start distance Dacc (the threshold of the vehicle distance D at which optimal acceleration control begins), inertial travel start speed Vcst (the threshold of the vehicle speed V1 at which inertial travel control begins), and inertial travel start distance Dcst (the threshold of the vehicle distance D at which inertial travel control begins) that minimize the energy consumption of the drive unit 21, and obtains the energy consumption at this time, and sets the energy consumption as the second energy consumption EN2.

[0212] Additionally, at this time, the vehicle driving assistance device 10 predicts the inter-vehicle distance D and the vehicle speed V1 when the vehicle 100 follows the preceding vehicle 200F through asynchronous switching follow control, and applies these inter-vehicle distances D and vehicle speed V1 to a mapping corresponding to the category of the preceding vehicle 200F (see reference). Figure 15 The energy consumption is obtained from the energy source and set as the basic energy consumption ENbase (refer to...). Figure 17 This allows us to obtain the difference between the energy consumption when the vehicle accelerates to 100 km / h using optimal acceleration control and the energy consumption when the vehicle accelerates to 100 km / h using follow-driving control (optimal acceleration reduction ΔENopt). Furthermore, when energy is consumed when switching from inertial driving control to optimal acceleration control, this energy consumption (action point switching increase ΔENsw) is obtained, and the optimal acceleration reduction ΔENopt is subtracted from the basic energy consumption Enbase (see reference). Figure 17 Furthermore, by adding an action point switching amplification ΔENsw (see reference) on top of it. Figure 17 This allows us to obtain the energy consumption of the drive unit 21 when the vehicle 100 is driven by asynchronous switching follow control (i.e., the second energy consumption EN2) (EN2 = Enbase - ΔENopt + ΔENsw).

[0213] Furthermore, if the obtained acceleration start speed Vacc is greater than the minimum permissible speed Vmin, then Vacc is the optimal speed with reduced energy consumption (optimal acceleration start speed Vacc_opt). Similarly, if the obtained inertial travel start speed Vcst is less than the maximum permissible speed Vmax, then Vcst is the optimal speed with reduced energy consumption (optimal inertial travel start speed Vcst_opt). Likewise, if the obtained acceleration start distance Dacc is less than the maximum permissible distance Dmax, then Dacc is the optimal distance with reduced energy consumption (optimal acceleration start distance Dacc_opt). Similarly, if the obtained inertial travel start distance Dcst is greater than the minimum permissible distance Dmin, then Dcst is the optimal distance with reduced energy consumption (optimal inertial travel start distance Dcst_opt).

[0214] Furthermore, the vehicle driving assistance device 10 compares the second energy consumption EN2 with the first energy consumption EN1, and performs asynchronous switching follow control when the second energy consumption EN2 is less than the first energy consumption EN1, and performs normal follow control when the second energy consumption EN2 is greater than the first energy consumption EN1.

[0215] Furthermore, when the vehicle driving assistance device 10 performs asynchronous switching follow control, and when the optimal switching permission condition C10 is met, it performs asynchronous switching follow control (optimal switching follow control) using the optimal acceleration start speed Vacc_opt, the optimal inertial travel start speed Vcst_opt, the optimal acceleration start distance Dacc_opt, and the optimal inertial travel start distance Dcst_opt. In this example, the optimal switching permission condition C10 is as follows: (1) the acceleration start distance Dacc obtained in the above manner is less than the maximum allowable distance Dmax, and (2) the inertial travel start distance Dcst obtained in the above manner is greater than the minimum allowable distance Dmin, and (3) the acceleration start speed Vacc obtained in the above manner is greater than the minimum allowable speed Vmin, and (4) the inertial travel start speed Vcst obtained in the above manner is less than the maximum allowable speed Vmax.

[0216] In this case, specifically, the vehicle driving assistance device 10 initiates inertial driving control when the vehicle speed V1 increases to reach the optimal inertial driving start speed Vcst_opt, or when the inter-vehicle distance D decreases to reach the optimal inertial driving start distance Dcst_opt; when the vehicle speed V1 decreases to reach the optimal acceleration start speed Vacc_opt; and when the inter-vehicle distance D increases to reach the optimal acceleration start distance Dacc_opt. That is, the vehicle driving assistance device 10 automatically accelerates or decelerates the vehicle 100 in a manner that maintains the vehicle speed V1 within a predetermined speed range defined by the optimal inertial driving start speed Vcst_opt and the optimal acceleration start speed Vacc_opt, or in a manner that maintains the inter-vehicle distance D within a predetermined distance range (second predetermined distance range) defined by the optimal inertial driving start distance Dcst_opt and the optimal acceleration start distance Dacc_opt, thereby enabling the vehicle 100 to follow the preceding vehicle 200F. In addition, the predetermined distance range (second predetermined distance range) defined by the optimal inertial driving start distance Dcst_opt and the optimal acceleration start distance Dacc_opt is set to be a larger range compared to the predetermined range (first predetermined distance range) in normal follow control.

[0217] On the other hand, if the optimal handover permission condition C10 is not met, the vehicle driving assistance device 10 performs asynchronous handover following control (limited handover following control) using the minimum permissible speed Vmin, maximum permissible distance Dmax, maximum permissible speed Vmax, and minimum permissible distance Dmin.

[0218] In this situation, specifically, the vehicle driving assistance device 10 initiates inertial driving control when the vehicle speed V1 increases to reach the maximum permissible speed Vmax, or when the inter-vehicle distance D decreases to reach the minimum permissible distance Dmin; it initiates optimal acceleration control when the vehicle speed V1 decreases to reach the minimum permissible speed Vmin, or when the inter-vehicle distance D increases to reach the maximum permissible distance Dmax. That is, the vehicle driving assistance device 10 automatically accelerates or decelerates the vehicle 100 in such a way that the vehicle speed V1 is maintained within a predetermined speed range defined by the maximum permissible speed Vmax and the minimum permissible speed Vmin, or that the inter-vehicle distance D is maintained within a predetermined distance range defined by the minimum permissible distance Dmin and the maximum permissible distance Dmax, thereby enabling the vehicle 100 to follow the preceding vehicle 200F.

[0219] Therefore, when the vehicle driving assistance device 10 is from Figure 8When the routine shown begins processing at step 800, the processing proceeds to step 805, and while obtaining the category of the preceding vehicle 200F (especially the size of the preceding vehicle 200F), the future preceding vehicle speed V2 is predicted.

[0220] Next, the vehicle driving assistance device 10 initiates the process to step 810 and selects a mapping (lookup table) corresponding to the category of the acquired preceding vehicle 200F. Next, the vehicle driving assistance device 10 initiates the process to step 815 and obtains the first energy consumption EN1 in the manner previously described using the mapping selected in step 810. Next, the vehicle driving assistance device 10 initiates the process to step 820 and sets the allowable distance range RDpmt and the allowable speed range RVpmt.

[0221] Next, the vehicle driving assistance device 10 initiates the process at step 825 and obtains the acceleration start speed Vacc, the inertial travel start speed Vcst, the acceleration start distance Dacc, and the inertial travel start distance Dcst. Next, the vehicle driving assistance device 10 initiates the process at step 830 and obtains the second energy consumption EN2 in the manner previously described, using the mapping selected in step 810.

[0222] Next, the vehicle driving assistance device 10 initiates step 835 and determines whether the second energy consumption EN2 is less than the first energy consumption EN1. If the second energy consumption EN2 is less than the first energy consumption EN1, the vehicle driving assistance device 10 determines "yes" in step 835 and initiates step 840, whereby it further determines whether the optimal switching permission condition C10 has been met.

[0223] If the optimal switching permission condition C10 has been met, the vehicle driving assistance device 10 determines "yes" in step 840 and proceeds to step 845, by executing... Figure 9 The example shown performs optimal switching follow control.

[0224] Therefore, when the process proceeds to step 845, the vehicle driving assistance device 10... Figure 9 The routine shown begins processing from step 900 and proceeds to step 905, whereby a determination is made as to whether the optimal switching acceleration condition C11 has been met. In this example, as part of this determination, the vehicle driving assistance device 10 checks whether the vehicle speed V1 has become less than the optimal acceleration start speed Vacc_opt, or whether the inter-vehicle distance D has become greater than the optimal acceleration start distance Dacc_opt.

[0225] If the optimal switching acceleration condition C11 is met, the vehicle driving assistance device 10 determines "yes" in step 905 and proceeds to step 910, thereby executing optimal acceleration control. Afterwards, the vehicle driving assistance device 10 temporarily terminates the processing of this routine.

[0226] On the other hand, if the optimal switching and following acceleration condition C11 is not met, the vehicle driving assistance device 10 determines "no" in step 905 and proceeds to step 915, whereby it further determines whether the optimal switching and following deceleration condition C12 has been met. In this example, as this determination, the vehicle driving assistance device 10 determines whether the vehicle speed V1 has become greater than the optimal inertial driving start speed Vcst_opt, or whether the inter-vehicle distance D has become less than the optimal inertial driving start distance Dcst_opt.

[0227] If the optimal switching and following deceleration condition C12 is met, the vehicle driving assistance device 10 determines "yes" in step 915 and proceeds to step 920, thereby executing inertial driving control. Afterward, the vehicle driving assistance device 10 temporarily terminates the processing of this routine.

[0228] On the other hand, if the optimal switching deceleration condition C12 is not met, the vehicle driving assistance device 10 determines "no" in step 915 and temporarily terminates the processing of this routine. In this case, if the vehicle driving assistance device 10 is performing optimal acceleration control at that time, it continues to perform optimal acceleration control; if it is performing inertial driving control at that time, it continues to perform inertial driving control.

[0229] In addition, the vehicle driving assistance device 10 is performing Figure 8 If the optimal switching permission condition C10 is not met at the processing time of step 840 in the example shown, the result in step 840 is "No" and the process proceeds to step 850, by executing... Figure 10 The example shown performs a limit switch follow control.

[0230] Therefore, when the process enters step 850, the vehicle driving assistance device 10 from Figure 10 The routine shown begins processing from step 1000 and proceeds to step 1005, where a determination is made as to whether the restriction switching acceleration condition C13 has been met. In this example, as part of this determination, the vehicle driving assistance device 10 determines whether the vehicle speed V1 is less than the minimum permissible speed Vmin, or whether the inter-vehicle distance D is greater than the maximum permissible distance Dmax.

[0231] If the condition C13 for limiting the switching of acceleration is met, the vehicle driving assistance device 10 determines "yes" in step 1005 and proceeds to step 1010, thereby executing optimal acceleration control. Afterwards, the vehicle driving assistance device 10 temporarily terminates the processing of this routine.

[0232] On the other hand, if the restriction on switching and accelerating is not met (C13), the vehicle driving assistance device 10 determines "no" in step 1005 and proceeds to step 1015, whereby it determines whether the restriction on switching and accelerating is met (C14). In this example, the vehicle driving assistance device 10 determines whether the vehicle speed V1 has become greater than the maximum permissible speed Vmax, or whether the inter-vehicle distance D has become less than the minimum permissible distance Dmin.

[0233] If the condition C14 for limiting the switching and following deceleration is met, the vehicle driving assistance device 10 determines "yes" in step 1015 and proceeds to step 1020, thereby executing inertial driving control. Afterward, the vehicle driving assistance device 10 temporarily terminates the processing of this routine.

[0234] On the other hand, if the restriction switching deceleration condition C14 is not met, the vehicle driving assistance device 10 determines "no" in step 1015 and temporarily terminates the processing of this routine.

[0235] In addition, the vehicle driving assistance device 10 is performing Figure 8 At the processing point of step 835 of the example shown, if the second energy consumption EN2 is greater than or equal to the first energy consumption EN1, a "No" condition is determined in step 835, and the process proceeds to step 855. Then, as previously described, the process is executed... Figure 13 The routine shown performs the usual follow control. Afterwards, the vehicle driving assistance device 10 temporarily terminates the processing of this routine.

[0236] The above describes the operation of the vehicle driving assistance device 10. According to the vehicle driving assistance device 10, even when the vehicle 100 cannot be driven by synchronous switching follow control, there is a situation where the vehicle 100 can be driven by asynchronous switching follow control, thus improving the energy efficiency of the drive unit 21.

[0237] Furthermore, the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the present invention.

[0238] For example, although the above-mentioned vehicle driving assistance device 10 uses the condition that driving assistance request condition C1 and efficiency priority request condition C2 have been met as the condition for performing asynchronous switching follow control (predetermined execution condition), the condition that efficiency priority request condition C2 has been met can be omitted, and only the condition that driving assistance request condition C1 has been met can be used.

[0239] Symbol Explanation

[0240] 10…Vehicle driving assistance device; 20…Vehicle driving device; 21…Drive device; 48…Vehicle speed detection device; 51…Driving assistance operator; 52…Efficiency priority driving operator; 60…Surrounding information detection device; 70…Transmitter / receiver device; 90…ECU; 100…This vehicle; 200F…Leading vehicle; 200S…Surrounding vehicles.

Claims

1. A vehicle driving assistance device, wherein, It is equipped with a control device, which performs a first follower control, a second follower control, and a third follower control. The first following control is a control method that automatically controls the acceleration and deceleration of the vehicle to maintain the inter-vehicle distance between the vehicle and the preceding vehicle within a first predetermined distance range, thereby enabling the vehicle to follow the preceding vehicle. The second following control is a control that automatically accelerates or decelerates the vehicle to follow the preceding vehicle, either by maintaining the vehicle's speed (which is its own speed) within a predetermined speed range or by maintaining the inter-vehicle distance within a second predetermined distance range that is larger than the first predetermined distance range. The third following control is a control that accelerates or decelerates the vehicle in a manner synchronized or substantially synchronized with the acceleration and deceleration of the preceding vehicle, thereby enabling the vehicle to follow the preceding vehicle. Furthermore, it involves accelerating the vehicle through optimal acceleration control when accelerating, and decelerating the vehicle through inertial control that allows the vehicle to maintain its inertial motion when decelerating. The optimal acceleration control is the control that activates the drive unit at the point where the energy consumption of the vehicle's drive unit is minimized or substantially minimized, thereby accelerating the vehicle. The control device is configured such that, The energy consumption of the vehicle's drive unit during the execution of the first follow control is predicted as the first energy consumption, and the energy consumption during the execution of the second follow control is predicted as the second energy consumption. The second follower control is executed when the second energy consumption is less than the first energy consumption, and the first follower control is executed when the second energy consumption is greater than or equal to the first energy consumption. The control device is configured to, upon detecting that another vehicle has a drive unit with the same or substantially the same power output characteristics as the drive unit of the vehicle, and that the other vehicle is traveling under the same control as the second or the third follow control, move the vehicle behind the other vehicle and execute the third follow control.

2. The vehicle driving assistance device as described in claim 1, wherein, The control device is configured such that, If the predetermined execution condition of requesting a reduction in the energy consumption of the vehicle's drive unit is met, the changes in the vehicle distance and the vehicle speed during the execution of the first follow control are predicted, and the energy consumption of the vehicle's drive unit during the execution of the first follow control is predicted as the first energy consumption based on the vehicle distance and the vehicle speed under the assumption that the changes have occurred in the predicted manner. Furthermore, the changes in the vehicle distance and the vehicle speed during the execution of the second follow control are predicted, and the energy consumption during the execution of the second follow control is predicted as the second energy consumption based on the vehicle distance and the vehicle speed under the assumption that the changes have occurred in the predicted manner.

3. The vehicle driving assistance device as described in claim 1 or claim 2, wherein, The second following control is as follows: when the vehicle speed increases to the upper limit of the predetermined speed range, the vehicle is decelerated by inertial travel, and when the vehicle speed decreases to the lower limit of the predetermined speed range, the vehicle is accelerated; or, when the inter-vehicle distance increases to the upper limit of the second predetermined distance range, the vehicle is accelerated, and when the inter-vehicle distance decreases to the lower limit of the second predetermined distance range, the vehicle is decelerated by inertial travel.

4. The vehicle driving assistance device as described in claim 1 or claim 2, wherein, The second following control is as follows: when accelerating the vehicle, the vehicle is accelerated by optimal acceleration control, and when decelerating the vehicle, the vehicle is decelerated by inertial driving control, wherein the optimal acceleration control is the control that causes the drive device to operate at the point where the energy consumption of the drive device is minimized or approximately minimized, thereby accelerating the vehicle.

5. The vehicle driving assistance device as claimed in claim 1 or claim 2, wherein, The control device is configured to set the range of vehicle speeds allowed according to the vehicle's driving environment as the predetermined speed range, or to set the range of inter-vehicle distances allowed according to the vehicle's driving environment as the second predetermined distance range.

6. The vehicle driving assistance device as claimed in claim 1 or claim 2, wherein, The control device is configured to predict the inter-vehicle distance and the vehicle speed when the first following control is executed, based on the speed of the leading vehicle when the first following control is executed, and to predict the inter-vehicle distance and the vehicle speed when the second following control is executed, based on the speed of the leading vehicle when the second following control is executed.

7. The vehicle driving assistance device as claimed in claim 1 or claim 2, wherein, The control device is configured to take into account the size of the advance vehicle in the prediction of the first energy consumption and the second energy consumption.

8. A vehicle driving assistance method, wherein the vehicle is driven by any one of a first follow control, a second follow control, and a third follow control, wherein, The first following control is a control method that automatically controls the acceleration and deceleration of the vehicle to maintain the inter-vehicle distance between the vehicle and the preceding vehicle within a first predetermined distance range, thereby enabling the vehicle to follow the preceding vehicle. The second following control is a control that automatically accelerates or decelerates the vehicle to follow the preceding vehicle, either by maintaining the vehicle's speed (which is its own speed) within a predetermined speed range or by maintaining the inter-vehicle distance within a second predetermined distance range that is larger than the first predetermined distance range. The third following control is a control that accelerates or decelerates the vehicle in a manner synchronized or substantially synchronized with the acceleration and deceleration of the preceding vehicle, thereby enabling the vehicle to follow the preceding vehicle. Furthermore, it involves accelerating the vehicle through optimal acceleration control when accelerating, and decelerating the vehicle through inertial control that allows the vehicle to maintain its inertial motion when decelerating. The optimal acceleration control is the control that activates the drive unit at the point where the energy consumption of the vehicle's drive unit is minimized or substantially minimized, thereby accelerating the vehicle. Among vehicle driving assistance methods, the following are included: The process of predicting the energy consumption of the vehicle's drive unit when the first follow control is executed as the first energy consumption, and predicting the energy consumption when the second follow control is executed as the second energy consumption; The process of performing the second follow-up control when the second energy consumption is less than the first energy consumption; and The first follow-up control step is executed when the second energy consumption is greater than or equal to the first energy consumption. If a vehicle is detected that has a drive unit with the same or substantially the same power output characteristics as the vehicle's drive unit, and that other vehicle is traveling under the same control as the second or third follow control, the vehicle is moved behind the other vehicle and the third follow control is executed.

9. A recording medium storing a vehicle driving assistance program, said vehicle driving assistance program enabling the vehicle to drive through any one of a first follow control, a second follow control, and a third follow control, wherein, The first following control is a control method that automatically controls the acceleration and deceleration of the vehicle to maintain the inter-vehicle distance between the vehicle and the preceding vehicle within a first predetermined distance range, thereby enabling the vehicle to follow the preceding vehicle. The second following control is a control that automatically accelerates or decelerates the vehicle to follow the preceding vehicle, either by maintaining the vehicle's speed (which is its own speed) within a predetermined speed range or by maintaining the inter-vehicle distance within a second predetermined distance range that is larger than the first predetermined distance range. The third following control is a control that accelerates or decelerates the vehicle in a manner synchronized or substantially synchronized with the acceleration and deceleration of the preceding vehicle, thereby enabling the vehicle to follow the preceding vehicle. Furthermore, it involves accelerating the vehicle through optimal acceleration control when accelerating, and decelerating the vehicle through inertial control that allows the vehicle to maintain its inertial motion when decelerating. The optimal acceleration control is the control that activates the drive unit at the point where the energy consumption of the vehicle's drive unit is minimized or substantially minimized, thereby accelerating the vehicle. The vehicle driving assistance program is configured such that, The energy consumption of the vehicle's drive unit during the execution of the first follow control is predicted as the first energy consumption, and the energy consumption during the execution of the second follow control is predicted as the second energy consumption. The second follower control is executed when the second energy consumption is less than the first energy consumption, and the first follower control is executed when the second energy consumption is greater than or equal to the first energy consumption. If a vehicle is detected that has a drive unit with the same or substantially the same power output characteristics as the vehicle's drive unit, and that other vehicle is traveling under the same control as the second or third follow control, the vehicle is moved behind the other vehicle and the third follow control is executed.

Images