Driving assistance systems

Abstract

Reduce the operational load on the driver. [Solution] A driving assistance device capable of controlling the vehicle speed based on a set vehicle speed set by the vehicle occupant, wherein when the difference between the current vehicle speed and the set vehicle speed is greater than or equal to a threshold, and the occupant performs either a change operation to change the set speed or a restart operation to resume interrupted vehicle speed control, the device executes a set vehicle speed change process to change the set vehicle speed to the current vehicle speed.

Description

Technical Field

[0001] The present disclosure relates to a driving support device.

Background Art

[0002] For example, Patent Document 1 discloses a driving support device for a vehicle capable of executing Adaptive Cruise Control (ACC). When the device described in Patent Document 1 detects a speed limit different from the set speed by an image recognition device, it displays the set speed and the speed limit so as to be comparable, and is configured to selectively maintain the set speed or switch to the speed limit according to the driver's operation state.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

[0004] In a situation where the current vehicle speed of the vehicle and the set speed of ACC deviate significantly, when the driver desires to change the set speed to the current vehicle speed, the driver has to repeatedly operate the switch for changing the set speed. If the driver performs such repeated operations while the vehicle is running, the operation load on the driver will increase.

[0005] The present disclosure has been made to solve the above problems, and an object thereof is to effectively reduce the operation load on the driver when changing the set speed.

[0006] The technology of the present disclosure is a driving support device capable of executing vehicle speed control for controlling the vehicle speed based on a set speed set by a vehicle occupant, When the difference between the vehicle's current speed and the set speed is greater than or equal to a threshold, and the occupant performs either a change operation to change the set speed or a restart operation to resume the suspended speed control, the set speed change process is executed to change the set speed to the current speed. It is characterized by the following: [Brief explanation of the drawing]

[0007] [Figure 1] This is a schematic diagram showing the hardware configuration of the vehicle according to this embodiment. [Figure 2] This is a schematic diagram showing the software configuration of the control device according to this embodiment. [Figure 3] This is a timing chart illustrating this embodiment. [Figure 4] This is a timing chart illustrating a conventional example. [Figure 5] This flowchart illustrates the routine for changing the set vehicle speed according to this embodiment. [Modes for carrying out the invention]

[0008] The driver assistance device according to this embodiment will be described below with reference to the drawings.

[0009] [Hardware configuration] Figure 1 is a schematic diagram showing the hardware configuration of vehicle VH according to this embodiment. Hereafter, vehicle VH may be referred to as "our vehicle" when it is necessary to distinguish it from other vehicles, etc.

[0010] Vehicle VH has an ECU (Electronic Control Unit) 10. The ECU 10 includes a CPU (Central Processing Unit) 11, ROM (Read Only Memory) 12, RAM (Random Access Memory) 13, and an interface device 14, etc. The CPU 11 is a processor that executes various programs stored in the ROM 12. The ROM 12 is a non-volatile memory that stores data necessary for the CPU 11 to execute various programs. The RAM 13 is a volatile memory that provides a work area that is expanded when various programs are executed by the CPU 11. The interface device 14 is a communication device for communicating with external devices.

[0011] The ECU10 is the central device that provides driver assistance such as ACC. Driver assistance is a concept that includes autonomous driving. The ECU10 is connected to the drive unit 20, steering unit 21, braking unit 22, internal sensor unit 30, external sensor unit 40, navigation unit 50, communication unit 60, ACC control unit 70, etc., in a communication manner.

[0012] The drive unit 20 generates a driving force that is transmitted to the drive wheels of the vehicle VH. Examples of the drive unit 20 include an electric motor and an engine. The vehicle VH may be a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV), a fuel cell electric vehicle (FCEV), a battery electric vehicle (BEV), or an engine-powered vehicle. The steering unit 21 applies steering force to the wheels of the vehicle VH. The braking unit 22 applies braking force to the wheels of the vehicle VH.

[0013] The internal sensor device 30 consists of sensors that acquire the state of the vehicle's VH. The internal sensor device 30 includes a wheel speed sensor 31, an accelerator sensor 32, a brake sensor 33, a steering angle sensor 34, a yaw rate sensor 35, a longitudinal acceleration sensor 36, and the like.

[0014] The wheel speed sensor 31 detects the vehicle speed (vehicle speed V) of the vehicle VH. The accelerator sensor 32 detects the amount of accelerator pedal operation by the driver (not shown). The brake sensor 33 detects the amount of brake pedal operation by the driver (not shown). The steering angle sensor 34 detects the rotation angle (steering angle) of the steering wheel or steering shaft (not shown). The yaw rate sensor 35 detects the yaw rate of the vehicle VH. The longitudinal acceleration sensor 36 detects the longitudinal acceleration of the vehicle VH. The internal sensor device 30 transmits the state of the vehicle VH detected by each sensor 31 to 36 to the ECU 10 at a predetermined interval.

[0015] The external sensor device 40 consists of sensors that recognize object information relating to objects around the vehicle VH. The external sensor device 40 includes a radar sensor 41, a camera sensor 42, etc. Here, object information can be, for example, surrounding vehicles, road markings, road signs, etc.

[0016] The radar sensor 41 detects targets present around the vehicle VH. The radar sensor 41 includes a millimeter-wave radar and / or a lidar. The millimeter-wave radar emits radio waves in the millimeter-wave band and receives millimeter waves reflected by targets within its radiation range. The millimeter-wave radar acquires the relative distance and relative speed between the vehicle VH and the target based on the phase difference between the transmitted millimeter waves and the received reflected waves, the attenuation level of the reflected waves, and the time from the transmission of the millimeter waves to the reception of the reflected waves. The lidar sequentially scans pulsed laser light with a wavelength shorter than millimeter waves in multiple directions and receives the reflected light reflected by targets to acquire the shape of targets detected around the vehicle VH, the relative distance and relative speed between the vehicle VH and the targets.

[0017] The camera sensor 42 captures images of the area around the vehicle VH and processes the captured image data to acquire target information around the vehicle VH. For example, a digital camera with an image sensor such as a CMOS or CCD can be used as the camera sensor 42. The target information includes the type of target detected around the vehicle VH, the relative distance between the vehicle VH and the target, and the relative speed. The type of target can be recognized, for example, by machine learning such as pattern matching.

[0018] The external sensor device 40 transmits the acquired target information to the ECU 10 at predetermined intervals. The external sensor device 40 does not necessarily need to include both the radar sensor 41 and the camera sensor 42; for example, it may include only the radar sensor 41 or only the camera sensor 42.

[0019] The navigation system 50 includes a location information acquisition device 51 and a map database 52. The location information acquisition device 51 is, for example, a GPS (Global Positioning System), GNSS (Global Navigation Satellite System), etc., and acquires the current location information of the vehicle VH. The map database 52 is a database of map information and is stored in a storage device (hard disk, flash memory, etc.) provided by the vehicle VH. The map information includes road information such as road speed limits. The map database 52 may also be stored in an external server that can communicate with the vehicle VH. In this case, the vehicle VH can acquire map information from the external server via the communication device 60.

[0020] The communication device 60 performs V2X communication. Specifically, the communication device 60 performs vehicle-to-vehicle communication (V2V) between the host vehicle VH and other vehicles, and performs vehicle-to-infrastructure communication (V2I) between the host vehicle VH and the infrastructure. Through V2X communication, the communication device 60 can acquire information around the host vehicle VH or provide information of the host vehicle VH. The communication device 60 transmits the acquired surrounding information to the ECU 10 at a predetermined cycle.

[0021] The ACC operation unit 70 is switches that a driver operates to perform various settings of ACC and the like. The ACC operation unit 70 includes, for example, a start switch 71 for selecting whether to start or end ACC, a setting switch 72 for setting the set vehicle speed Vt and the set inter-vehicle distance (or the set inter-vehicle time) of ACC, a cancel switch 73 for temporarily canceling the running ACC, a resume switch 74 for resuming ACC, and the like. Note that some of these switches (for example, the cancel switch 73 and the resume switch 74) may be integrated into one switch.

[0022] [Software Configuration] FIG. 2 is a schematic diagram showing the software configuration of the control device according to the present embodiment.

[0023] As shown in FIG. 2, the ECU 10 includes functional elements such as an ACC control unit 100 and a set vehicle speed change unit 110. These functional elements 100 and 110 are realized by the CPU 11 of the ECU 10 reading out the program stored in the ROM 12 and executing it in the RAM 13. Note that all or part of the functional elements 100 and 110 can also be provided in another ECU separate from the ECU 10 or an information processing device of a facility (such as a management center) capable of communicating with the vehicle VH.

[0024] The ACC control unit 100 performs ACC based on the set vehicle speed Vt or the set inter-vehicle distance (set inter-vehicle time). As ACC itself is well known, it will be briefly explained below. ACC includes two types of control: constant speed driving control and follow driving control. Constant speed driving control is a control that makes the vehicle VH drive at a constant speed according to the set vehicle speed Vt without requiring the driver to operate the accelerator or brake. Follow driving control is a control that makes the vehicle VH follow the preceding vehicle so that the actual inter-vehicle distance between the preceding vehicle and the vehicle VH becomes the set inter-vehicle distance (set inter-vehicle time) without requiring the driver to operate the accelerator or brake. The preceding vehicle is a vehicle that is in the area in front of the vehicle VH and directly in front of the vehicle VH.

[0025] When the activation switch 71 of the ACC operation unit 70 is turned ON, the ACC control unit 100 searches for a preceding vehicle to follow based on the detection results of the external sensor device 40. If no preceding vehicle exists, the ACC control unit 100 performs constant speed driving control. In this case, the ACC control unit 100 controls the operation of the drive unit 20 and brake unit 22 based on the target acceleration calculated from the deviation between the vehicle speed V and the set vehicle speed Vt. The vehicle speed V can be obtained based on the detection results of the wheel speed sensor 31. On the other hand, if a preceding vehicle exists, the ACC control unit 100 performs follow driving control. In this case, the ACC control unit 100 controls the operation of the drive unit 20 and brake unit 22 based on the target acceleration calculated from the deviation between the actual distance between vehicles and the set distance (set time between vehicles). The actual distance between the vehicle VH and the preceding vehicle can be obtained based on the detection results of the external sensor device 40.

[0026] Here, we will explain how the driver sets the set vehicle speed Vt. When the driver activates ACC by turning on the activation switch 71 while the vehicle VH is in motion, the set vehicle speed Vt is set to the current vehicle speed V. In this state, if the driver operates the setting switch 72 in a predetermined direction, the set vehicle speed Vt increases by a predetermined first speed (for example, 1 km / h). Hereinafter, the driver's operation of the setting switch 72 in a predetermined direction will be referred to as an "up operation". Also, with ACC activated, if the driver holds the up operation of the setting switch 72, the set vehicle speed Vt increases by a predetermined second speed (for example, 5 to 10 km / h) that is greater than the first speed. On the other hand, with ACC activated, if the driver operates the setting switch 72 in the opposite direction to the predetermined direction, the set vehicle speed Vt decreases by a first speed (for example, 1 km / h). Hereinafter, the driver's operation of the setting switch 72 in the opposite direction will be referred to as a "down operation". Furthermore, when ACC is activated, if the driver holds down the setting switch 72, the set vehicle speed Vt will decrease by a second speed (for example, 5-10 km / h).

[0027] For example, when the driver temporarily cancels ACC and then restarts ACC by turning on the resume switch 74, if there is a large difference between the current vehicle speed V of the vehicle VH and the set vehicle speed Vt that was set before the ACC was canceled, the driver may have to repeatedly operate the setting switch 72 to change the set vehicle speed Vt. If the driver has to perform such repeated operations while the vehicle VH is in motion, the driver's workload will increase. In addition, the driver will have to check sequentially whether the set vehicle speed Vt has actually been changed by looking at the meter while repeatedly operating the setting switch 72, which can be a cumbersome issue. Examples of such scenarios include the following patterns.

[0028] [Pattern 1] The driver was driving on a public road using ACC at a predetermined set speed Vt (e.g., 60 km / h), and temporarily canceled ACC when passing through a toll booth or similar. Subsequently, the driver moved to a highway with a higher speed limit than the public road, restarted ACC by turning on the resume switch 74, and increased the set speed Vt to a desired speed (e.g., 120 km / h) by operating the setting switch 72 up.

[0029] [Pattern 2] When the driver is driving on a highway or similar road at a predetermined set speed Vt (e.g., 80 km / h) using ACC, the speed limit of the road being driven on becomes higher than the set speed Vt (e.g., 120 km / h). Subsequently, the driver increases the set speed Vt to the speed limit (e.g., 120 km / h) by operating the setting switch 72 up.

[0030] [Pattern 3] When the driver is driving on a highway or similar road at a predetermined set speed Vt (for example, 80 km / h) using ACC, they perform an override by pressing the accelerator pedal. Subsequently, when the driver continues the override and accelerates the vehicle VH to a speed faster than the set speed Vt (for example, 120 km / h), they perform the up operation on the setting switch 72.

[0031] [Pattern 4] The driver was driving on a highway using ACC at a predetermined set speed Vt (e.g., 120 km / h), and temporarily canceled ACC when passing through a toll booth or similar. Subsequently, the driver moved to a regular road with a lower speed limit than the highway, restarted ACC by turning on the resume switch 74, and reduced the set speed Vt to a desired speed (e.g., 60 km / h) by turning down the setting switch 72.

[0032] [Pattern 5] When the driver is driving on a highway or similar road at a predetermined set speed Vt (e.g., 120 km / h) using ACC, the speed limit of the road being driven becomes lower than the set speed Vt (e.g., 80 km / h). Subsequently, the driver reduces the set speed Vt to the speed limit (e.g., 80 km / h) by operating the setting switch 72 down.

[0033] [Pattern 6] When the driver is driving on a highway or similar road at a predetermined set speed Vt (for example, 120 km / h) using ACC, a preceding vehicle that is following at a slower speed than the set speed Vt (for example, traveling at 80 km / h) is detected. Subsequently, if the following at a slower speed than the set speed Vt continues for an extended period, the driver changes their mind and decides to reduce the set speed Vt by operating the setting switch 72 down.

[0034] These patterns 1 through 6 are just examples of scenarios where repeated operation of the setting switch 72 is required, and other patterns are also possible.

[0035] The set vehicle speed change unit 110 changes the set vehicle speed Vt to the current vehicle speed V depending on the situation, thereby reducing the driver's operational burden by eliminating the need for repeated operation of the setting switch 72 by the driver. Specifically, the set vehicle speed change unit 110 executes a set vehicle speed change process to change the set vehicle speed Vt to the current vehicle speed V when the driver turns on the resume switch 74 or turns up or down the setting switch 72 while the difference (absolute value) between the current vehicle speed V and the set vehicle speed Vt of the vehicle VH is greater than or equal to a predetermined threshold. The threshold is not particularly limited, but it should be based on the speed difference that would require the driver to repeatedly operate the setting switch 72 to change the set vehicle speed Vt to the current vehicle speed V. In other words, the threshold should be a value greater than the second speed (for example, 5 to 10 km / h), which is the speed range in which the set vehicle speed Vt can be changed by holding down the up or down operation of the setting switch 72.

[0036] Figure 3 is a timing chart for this embodiment, which performs the set vehicle speed change process. Figure 4 is a timing chart for a conventional example (comparative example) in which the set vehicle speed change process is not performed. Note that Figures 3 and 4 show the case where the set vehicle speed Vt is increased. The process for decreasing the set vehicle speed Vt is basically the same, so the explanation is omitted.

[0037] First, let's explain the conventional example shown in Figure 4. Time t1 is the moment when the driver turns on the resume switch 74 when the difference between the current vehicle speed V and the set vehicle speed Vt of the vehicle VH is greater than or equal to a threshold. In the conventional example, even if the driver turns up the setting switch 72 after turning on the resume switch 74, the set vehicle speed Vt only increases by the first speed (e.g., 1 km / h) or the second speed (e.g., 5-10 km / h). Therefore, in order for the driver to increase the set vehicle speed Vt to the current vehicle speed V, the driver must repeatedly operate the setting switch 72 from time t2 to time t4, which increases the driver's operational burden. In addition, in the conventional example, the driver must continuously press the accelerator pedal in parallel with operating the setting switch 72, which is a cumbersome task for the driver.

[0038] In contrast, in this embodiment shown in Figure 3, when the driver turns on the resume switch 74 (or turns up the setting switch 72) at time t1, when the difference between the current vehicle speed V and the set vehicle speed Vt of the vehicle VH is greater than or equal to a threshold, the set vehicle speed change process is executed. That is, at time t2, the set vehicle speed Vt is changed to the current vehicle speed V. This eliminates the need for the driver to repeatedly operate the setting switch 72, and reliably reduces the driver's operational load. Furthermore, because the set vehicle speed Vt is changed to the current vehicle speed V earlier, the driver can release the accelerator pedal at time t3 earlier than in the conventional example, effectively reducing the hassle of accelerator operation. In addition, compared to the conventional example, the number of times the driver needs to visually check the meter to confirm the change in the set vehicle speed Vt can be effectively reduced.

[0039] Figure 5 is a flowchart illustrating the routine for changing the set vehicle speed executed by the CPU 11 of the ECU 10. This routine is started, for example, when the ACC is activated by turning on the start switch 71.

[0040] In step S100, the ECU 10 determines whether the absolute value of the difference between the current vehicle speed V and the set vehicle speed Vt of the vehicle VH is greater than or equal to a threshold. If the absolute value of the difference between the current vehicle speed V and the set vehicle speed Vt of the vehicle VH is greater than or equal to the threshold (Yes), the ECU 10 proceeds to the process in step S110. On the other hand, if the absolute value of the difference between the current vehicle speed V and the set vehicle speed Vt of the vehicle VH is less than the threshold (No), the ECU 10 proceeds to the process in step S150.

[0041] In step S110, the ECU 10 determines whether the driver has performed one of the following operations: turning on the resume switch 74, turning up the setting switch 72, or turning down the setting switch 72. If the driver has performed one of the following operations (Yes), the ECU 10 proceeds to step S120. On the other hand, if the driver has not performed any of the following operations (No), the ECU 10 returns to this routine without performing the set vehicle speed change process. In other words, normal ACC operation continues.

[0042] In step S120, the ECU10 performs a set vehicle speed change process, which changes the set vehicle speed Vt to the current vehicle speed V. After that, the ECU10 returns to this routine, that is, it returns to normal ACC.

[0043] When the process proceeds from step S100 to step S150, the ECU 10 determines whether the driver has operated the setting switch 72 up. If the driver has operated the setting switch 72 up (Yes), the ECU 10 proceeds to step S155, increases the set vehicle speed Vt by the first or second speed in accordance with the operation of the setting switch 72, and returns to this routine. On the other hand, if the driver has not operated the setting switch 72 up (No), the ECU 10 proceeds to step S160.

[0044] In step S160, the ECU 10 determines whether the driver has operated the setting switch 72 down. Note that the processes in steps S150 and S160 are not in any particular order, and their order may be changed. If the driver operates the setting switch 72 down (Yes), the ECU 10 proceeds to step S165, decreases the set vehicle speed Vt by the first or second speed in accordance with the operation of the setting switch 72, and returns to this routine. On the other hand, if the driver does not operate the setting switch 72 down (No), the ECU 10 returns to this routine without changing the set vehicle speed Vt.

[0045] Although the driving assistance device according to this embodiment has been described above, this disclosure is not limited to the above-described embodiment, and various modifications are possible without departing from the purpose of this disclosure.

[0046] [Example 1] For example, the ECU 10 may change the set vehicle speed Vt to the vehicle speed of a surrounding vehicle when the driver turns on the resume switch 74 or turns up or down the setting switch 72 while the difference (absolute value) between the current vehicle speed V and the set vehicle speed Vt of the vehicle VH is greater than or equal to a predetermined threshold. Surrounding vehicles are not particularly limited, but examples include a preceding vehicle traveling in front of the vehicle VH, or an adjacent vehicle traveling in an adjacent lane adjacent to the vehicle's lane. The vehicle speed of the surrounding vehicle may be obtained based on the detection result of the external sensor device 40, or it may be obtained through V2V communication. In the modified example 1, as in the above embodiment, repeated operation of the setting switch 72 by the driver is not required, and the driver's operational load can be reliably reduced.

[0047] [Differentiation 2] For example, the ECU 10 may change the set speed Vt to the speed limit when the driver turns on the resume switch 74 or turns up or down the setting switch 72 while the vehicle VH is traveling on the road, if the difference (absolute value) between the speed limit and the set speed Vt is greater than or equal to a predetermined threshold. Alternatively, the ECU 10 may learn the location information of the road the vehicle VH is traveling on and the vehicle speed V of the vehicle VH, and change the set speed Vt to the learned value. The speed limit can be obtained, for example, based on the detection results of the location information acquisition device 51 equipped with the navigation device 50 and the map database 52. In the modified example 2, as in the above embodiment, repeated operation of the setting switch 72 by the driver is not required, and the driver's operational load can be reliably reduced.

[0048] [Difference 3] For example, the ECU 10 may acquire the average vehicle speed of multiple surrounding vehicles traveling around its own vehicle VH from a server device such as a management center via V2I communication, and when the driver turns on the resume switch 74 or turns up or down the setting switch 72 while the difference (absolute value) between the acquired average vehicle speed and the set vehicle speed Vt is greater than or equal to a predetermined threshold, the ECU 10 may change the set vehicle speed Vt to the average vehicle speed. The average vehicle speed of multiple surrounding vehicles may be acquired via V2V communication. In the modified example 3, as in the above embodiment, repeated operation of the setting switch 72 by the driver is not required, and the driver's operational load can be reliably reduced.

[0049] [others] Furthermore, the technology disclosed herein is not limited to vehicles capable of performing ACC, but can also be applied to vehicles capable of performing only constant-speed driving control (cruise control).

Claims

1. A driver assistance device capable of performing vehicle speed control, which controls the vehicle speed of the vehicle based on a set vehicle speed set by the vehicle occupants, When the difference between the vehicle's current speed and the set speed is greater than or equal to a threshold, and the occupant performs either a change operation to change the set speed or a restart operation to resume the suspended speed control, the set speed change process is executed to change the set speed to the current speed. A driving assistance device characterized by the following features.

2. A driving support device according to claim 1, The aforementioned set speed is configured to be increased or decreased by predetermined speeds in response to the operation of the control unit by the occupant. When the occupant performs either the change operation or the restart operation, if the difference between the current vehicle speed and the set vehicle speed is greater than the predetermined speed, the set vehicle speed change process is executed. A driving assistance device characterized by the following features.

3. A driver assistance device capable of performing vehicle speed control, which controls the vehicle speed of the vehicle based on a set vehicle speed set by the vehicle occupants, The system acquires the vehicle speeds of surrounding vehicles traveling in the area surrounding the vehicle, including the area in front of and to the side of the vehicle. When the difference between the current vehicle speed of the vehicle and the set vehicle speed is greater than or equal to a threshold, and the occupant performs either a change operation to change the set speed or a restart operation to resume the interrupted vehicle speed control, the system executes a set vehicle speed change process to change the set vehicle speed to the vehicle speed of the surrounding vehicles. A driving assistance device characterized by the following features.

4. A driver assistance device capable of performing vehicle speed control, which controls the vehicle speed of the vehicle based on a set vehicle speed set by the vehicle occupants, Based on the detection results of the location information detection device that detects the current position of the vehicle and a map database that includes road speed limit information, the speed limit of the road the vehicle is traveling on is obtained, and if the difference between the speed limit and the set speed is greater than or equal to a threshold, and the occupant performs either a change operation to change the set speed or a restart operation to resume the interrupted speed control, the set speed change process is executed to change the set speed to the speed limit. A driving assistance device characterized by the following features.

5. A driver assistance device capable of performing vehicle speed control, which controls the vehicle speed of the vehicle based on a set vehicle speed set by the vehicle occupants, The system acquires the average vehicle speed of multiple surrounding vehicles traveling around the vehicle via vehicle-to-infrastructure communication or vehicle-to-vehicle communication. When the difference between the average vehicle speed and the set vehicle speed is greater than or equal to a threshold, and the occupant performs either a change operation to change the set speed or a restart operation to resume the interrupted vehicle speed control, the system executes a set vehicle speed change process to change the set vehicle speed to the average vehicle speed. A driving assistance device characterized by the following features.

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