Vehicle driving control system

Abstract

The present invention provides a vehicle driving control device that can prevent occupants from feeling uneasy due to a decrease in the distance between their vehicle and the preceding vehicle when the mode selection means is operated while the control mode is set to the inter-vehicle distance control mode. [Solution] A vehicle driving control device equipped with a driver assistance ECU as a control unit that switches the control mode between a constant speed driving control mode and a distance control mode when a select switch, which is a control mode switching switch, is operated (S10), wherein the driver assistance ECU does not switch the control mode to the constant speed driving control mode (S80) when the select switch is operated while the control mode is in the distance control mode (S10, S20) if the vehicle is automatically decelerating (S50) or if the distance between the vehicle and the preceding vehicle is less than or equal to the reference distance (S60).

Description

Technical Field

[0001] The present invention relates to a driving control device for vehicles such as automobiles.

Background Art

[0002] As one of the driving control devices for vehicles such as automobiles, a driving control device that executes following inter-vehicle distance control including two types of control, inter-vehicle distance control and constant speed driving control, is known. For example, Patent Document 1 below describes a driving control device having mode selection means for selecting an inter-vehicle distance control mode or a constant speed driving control mode, and executing following inter-vehicle distance control in the mode selected by the mode selection means.

[0003] According to this type of driving control device, the driver can operate the mode selection means to execute following inter-vehicle distance control in a desired inter-vehicle distance control mode or constant speed driving control mode, and switch the control mode as necessary.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

[0005] 〔Problems to be Solved by the Invention〕 In the driving control device as described above, when the mode selection means is operated and the control mode is switched to the constant speed driving mode in a situation where the control mode is the inter-vehicle distance control mode, the inter-vehicle distance between the host vehicle and the preceding vehicle becomes smaller, and the passengers may feel uneasy.

[0006] For example, in a situation where the preceding vehicle is slowing down and the vehicle is automatically slowing down so that the distance between the vehicle and the preceding vehicle becomes the target distance, if the mode selection means is operated and the control mode is set to constant speed driving mode, the vehicle's speed is controlled to become the target speed. As a result, the vehicle's speed becomes higher than the preceding vehicle's speed, the vehicle approaches the preceding vehicle relatively, and the distance between the vehicle and the preceding vehicle decreases.

[0007] Furthermore, for example, when a preceding vehicle begins to climb a slope and the distance between your vehicle and the preceding vehicle decreases, if the mode selection means is operated and the control mode is set to constant speed driving mode, the speed of your vehicle is controlled to reach the target speed. Therefore, depending on the target speed, the speed of your vehicle may become higher than the speed of the preceding vehicle, and in this case as well, your vehicle will relatively approach the preceding vehicle, and the distance between your vehicle and the preceding vehicle will decrease.

[0008] The main objective of the present invention is to prevent occupants from feeling uneasy due to a decrease in the distance between their own vehicle and the preceding vehicle when the mode selection means is operated while the control mode is set to the inter-vehicle distance control mode.

[0009] [Means for solving the problem and the effects of the invention] According to the present invention, a vehicle driving control device (100) is provided that includes a control unit (driving support ECU 10) that switches the control mode between a constant speed driving control mode and an inter-vehicle distance control mode when a control mode switching switch (select switch 18B) is operated (S10).

[0010] The control unit (driving support ECU 10) is configured such that, even if the control mode switch is operated when the control mode is set to the distance control mode (S10, S20), it will not switch the control mode to the constant speed driving control mode (S80) if the vehicle itself (102) is automatically decelerating (S50) or if the distance between the vehicle itself and the preceding vehicle (110) (L) is less than or equal to the reference distance (Lc) (S60).

[0011] When the control mode is set to the distance control mode, if the preceding vehicle decelerates, the distance between your vehicle and the preceding vehicle temporarily becomes smaller than the target distance, and your vehicle automatically decelerates. Therefore, if the control mode switch is operated in such a situation and the control mode is switched to the constant speed driving control mode, the vehicle's speed is controlled to reach the target speed. As a result, your vehicle may move relatively closer to the preceding vehicle, and the distance between your vehicle and the preceding vehicle may become even smaller.

[0012] According to the above configuration of the present invention, even if the control mode switching switch is operated, the control mode cannot be switched to the constant speed driving control mode when the vehicle is automatically decelerating or when the distance between the vehicle and the preceding vehicle is less than or equal to the reference distance. Therefore, since the vehicle speed of the vehicle is controlled to reach the target speed, the vehicle will not approach the preceding vehicle relatively, thus preventing occupants from feeling uneasy due to a decrease in the distance between the vehicle and the preceding vehicle.

[0013] In addition, according to one aspect of the present invention, when the control mode switching switch is operated while the control mode is set to the inter-vehicle distance control mode (S10, S20), the control unit (driving support ECU 10) determines whether the conditions are met for a predetermined time (Tc) such that the vehicle (102) is automatically decelerating or the inter-vehicle distance (L) between the vehicle and the preceding vehicle (110) is less than or equal to the reference inter-vehicle distance (Lc) (S50, S60). If it is determined that the conditions are met, the control unit (driving support ECU 10) is configured not to switch the control mode to the constant speed driving control mode (S80).

[0014] In the above description, to aid in understanding the present invention, the names and / or reference numerals used in the embodiments of the invention corresponding to those embodiments described later are indicated in parentheses. However, the components of the present invention are not limited to the components of the embodiments corresponding to the names and / or reference numerals indicated in parentheses. Other objects, other features and incidental advantages of the present invention will be readily apparent from the description of embodiments of the present invention, which will be described with reference to the following drawings. [Brief explanation of the drawing]

[0015] [Figure 1] This is a schematic diagram showing an embodiment of a vehicle driving control device according to the present invention. [Figure 2] This flowchart shows the ACC mode switching control routine in the embodiment. [Figure 3] This diagram shows the case where your vehicle is not undergoing automatic deceleration due to automatic braking, and the distance between your vehicle and the vehicle in front of you exceeds the standard distance. [Figure 4] This diagram shows a situation where your vehicle is not undergoing automatic deceleration due to automatic braking, but the distance between your vehicle and the vehicle ahead is below the standard distance. [Figure 5] This diagram shows the situation when the vehicle is undergoing automatic deceleration due to automatic braking. [Figure 6] This diagram shows the case where a time period longer than the specified time has elapsed since the selector switch was operated. [Modes for carrying out the invention]

[0016] A vehicle driving control device according to an embodiment of the present invention will be described in detail below with reference to the attached figures.

[0017] As shown in FIG. 1, a driving control device 100 according to an embodiment of the present invention is applied to a vehicle 102 and includes a driving support ECU 10. The vehicle 102 is a vehicle capable of autonomous driving and includes a drive ECU 20, a brake ECU 30, and a meter ECU 50. An ECU means an electronic control unit (Electronic Control Unit) mainly including a microcomputer.

[0018] The microcomputer of each ECU includes a CPU, a ROM, a RAM, a readable and writable non-volatile memory (N / M), an interface (I / F), and the like. The CPU realizes various functions by executing instructions (programs, routines) stored in the ROM. Further, these ECUs are connected to each other via a CAN (Controller Area Network) 104 so as to be able to exchange data (communicate). Therefore, the detection values of sensors (including switches) connected to a specific ECU are also transmitted to other ECUs.

[0019] The driving support ECU 10 is a central control device that performs driving support running control such as following inter-vehicle distance control (Adaptive Cruise Control) and deceleration support control. In the embodiment, the driving support ECU 10 cooperates with other ECUs to execute following inter-vehicle distance control as will be described in detail later. The following inter-vehicle distance control is abbreviated as ACC and includes two types of control: constant speed running control and preceding vehicle following control.

[0020] A camera sensor 12, a radar sensor 14, and a setting operation device 16 are connected to the driving support ECU 10. The camera sensor 12 and the radar sensor 14 each include a plurality of camera devices and a plurality of radar devices. The camera sensor 12 and the radar sensor 14 function as a target detection device 15 that detects at least a preceding vehicle in front of the vehicle 102.

[0021] Each camera device of the camera sensor 12 includes a camera unit that captures the surroundings of the vehicle 102, and a recognition unit that analyzes the image data captured by the camera unit to recognize object targets such as white lines on the road and other vehicles. The recognition unit supplies information regarding the recognized object targets to the driving support ECU 10 at predetermined time intervals.

[0022] Each radar device of the radar sensor 14 uses radio waves in the millimeter wave band to detect the distance between the host vehicle and a three-dimensional object, the relative speed between the host vehicle and the three-dimensional object, and the relative position (direction) of the three-dimensional object with respect to the host vehicle, and supplies information representing them to the driving support ECU 10 at predetermined time intervals. Note that, instead of or in addition to the radar sensor 14, LiDAR (Light Detection And Ranging) may be used.

[0023] The setting operator 16 is provided at a position operable by the driver, such as a steering wheel not shown in FIG. 1, and is configured to be operated by the driver. The setting operator 16 includes an ACC switch 18. The ACC switch 18 includes a select switch 18A, a set switch 18B, a following distance switch 18C, a resume switch 18D, and a cancel switch 18E.

[0024] The select switch 18A is a switch for switching and setting the ACC mode to a constant speed control mode or an inter-vehicle distance control mode (preceding vehicle following control mode), and functions as a control mode switching switch. The set switch 18B is a switch for setting the target vehicle speed Vt in the constant speed control mode and turning on the ACC. The following distance switch 18C is a switch for setting the target inter-vehicle distance Lt from the preceding vehicle in the inter-vehicle distance control mode. The resume switch 18D is a switch for resuming the ACC when the ACC is interrupted due to a braking operation or a driving operation performed by the driver during the ACC. The cancel switch 18E is a switch for ending the ACC.

[0025] The drive ECU 20 is connected to a drive unit 22 that accelerates the vehicle 102 by applying driving force to the drive wheels 24. Normally, the drive ECU 20 controls the drive unit 22 so that the driving force generated by the drive unit 22 changes in accordance with the driver's driving operation, and when it receives a command signal from the driver assistance ECU 10, it controls the drive unit 22 based on the command signal.

[0026] The braking ECU 30 is connected to a braking device 32 that decelerates the vehicle 102 by applying braking force to the wheels 34. Normally, the braking ECU 30 controls the braking device 32 so that the braking force generated by the braking device 32 changes in accordance with the driver's braking operation. When it receives a command signal from the driver assistance ECU 10, it performs automatic braking by controlling the braking device 32 based on the command signal. Note that the wheels 34 include the drive wheels 24.

[0027] Therefore, the braking ECU 30 and the braking device 32 work together to function as an automatic braking system. Note that even when braking force is applied to the wheels by the automatic braking system, the brake lights, which are not shown in Figure 1, are illuminated.

[0028] The meter ECU 50 is connected to a display unit 52 and a speaker 54, which display the control status of the driver assistance ECU 10. The display unit 52 may be, for example, a multi-information display that displays meters and various other information, or it may be a display for a navigation system. When the display unit 52 receives a signal from the driver assistance ECU 10, it may display the control status, such as ACC. The display unit 52 also displays visual warnings, and the speaker 54 emits audible warnings. Therefore, the display unit 52 and speaker 54 function as a notification device 56 that informs the driver of warnings and other information.

[0029] The driving operation sensor 60 and the vehicle condition sensor 70 are also connected to CAN 104. Information detected by the driving operation sensor 60 and the vehicle condition sensor 70 (referred to as sensor information) is transmitted to CAN 104. The sensor information transmitted to CAN 104 can be used as appropriate by each ECU. Note that the sensor information may be information from a sensor connected to a specific ECU and transmitted to CAN 104 from that specific ECU.

[0030] The driving operation sensor 60 includes a drive operation amount sensor for detecting the amount of operation of the accelerator pedal, a braking operation amount sensor for detecting master cylinder pressure or the force applied to the brake pedal, and a brake switch for detecting whether or not the brake pedal is operated. The driving operation sensor 60 also includes a steering angle sensor for detecting the steering angle, a steering torque sensor for detecting the steering torque, and the like.

[0031] The vehicle condition sensor 70 includes a vehicle speed sensor for detecting the vehicle speed V of the vehicle 102, a longitudinal acceleration sensor for detecting the acceleration of the vehicle in the longitudinal direction, a lateral acceleration sensor for detecting the acceleration of the vehicle in the lateral direction, and a yaw rate sensor for detecting the yaw rate of the vehicle.

[0032] When the set switch 18B is turned on, the driver assistance ECU 10 starts ACC in the mode set by the select switch 18A, and when the cancel switch 18E is operated, ACC ends. Also, when the driver assistance ECU 10 is in the distance control mode, and the select switch 18A is operated, the driver assistance ECU 10 switches the ACC mode to the constant speed driving control mode. Conversely, when the driver assistance ECU 10 is in the constant speed driving control mode, and the select switch 18A is operated, the driver assistance ECU 10 switches the ACC mode to the distance control mode.

[0033] When the ACC mode is the inter-vehicle distance control mode, without requiring a driving operation by the driver, the driving force is automatically controlled so that the inter-vehicle distance between the host vehicle and the preceding vehicle (the following target vehicle) becomes the target inter-vehicle distance Lt and the host vehicle follows and travels behind the preceding vehicle. Also, when the ACC mode is the constant speed cruise control mode, the driving force is automatically controlled so that the vehicle speed V of the host vehicle becomes the target speed (set speed) Vt.

[0034] As will be described in detail later, in a situation where the ACC mode is the inter-vehicle distance control mode, even if the select switch 18A is operated, when the vehicle 102 is automatically decelerating or when the inter-vehicle distance L between the host vehicle and the preceding vehicle is less than or equal to the reference value Lc, the ACC mode cannot be switched to the constant speed cruise control mode.

[0035] In the embodiment, the ROM of the driving support ECU 10 stores an ACC control mode switching control program corresponding to the flowchart shown in FIG. 2.

[0036] <ACC Mode Switching Control (FIG. 2)> Next, the ACC mode switching control in the embodiment will be described with reference to the flowchart shown in FIG. 2. The mode switching control according to the flowchart shown in FIG. 2 is repeatedly executed by the CPU of the driving support ECU 10 at predetermined time intervals in a situation where the set switch 18B of the switch 18 is on.

[0037] First, in step S10, the CPU determines whether the select switch 18A has been operated. When a negative determination is made, this control is temporarily terminated and the ACC mode is not switched. When an affirmative determination is made, this control proceeds to step S20.

[0038] The CPU determines whether the ACC mode is the inter-vehicle distance control mode. When an affirmative determination is made, this control proceeds to step S40. When a negative determination is made, this control proceeds to step S30.

[0039] In step S30, the CPU sets the ACC mode to the distance control mode. The CPU also outputs a command signal to the meter ECU 50, which displays on the display unit 52 that the ACC mode is the distance control mode. When the ACC mode is the distance control mode, the ACC mode is maintained in the distance control mode, and the display on the display unit 52 is maintained.

[0040] In step S40, the CPU determines whether the elapsed time T since the select switch 18A was operated is less than or equal to the reference time Tc. If a negative determination is made, the control proceeds to step S70; if a positive determination is made, the control proceeds to step S50. The reference time Tc may be a preset positive constant, but in this embodiment, it is variably set according to the vehicle speed such that it increases as the vehicle speed V increases.

[0041] In step S50, the CPU determines whether the vehicle 102 is undergoing automatic deceleration due to automatic braking. If the determination is positive, the control proceeds to step S80; if the determination is negative, the control proceeds to step S60.

[0042] In step S60, the CPU determines whether the distance L between vehicle 102 and the preceding vehicle is less than or equal to the reference distance Lc. If the determination is negative, the control proceeds to step S70; if the determination is positive, the control proceeds to step S80. The reference distance Lc may be a positive constant less than or equal to the distance Lt, but in this embodiment, it is variably set according to the vehicle speed so that it increases as the vehicle speed V increases.

[0043] In step S70, the CPU switches and sets the ACC mode to constant speed driving control mode. The CPU also outputs a command signal to the meter ECU 50, which displays on the display unit 52 that the ACC mode is constant speed driving control mode.

[0044] In step S80, the CPU outputs a command signal to the meter ECU 50 to display and notify on the display 52 that the switching of the ACC mode is not possible. Further, the CPU outputs a command signal to the meter ECU 50 to notify by voice from the speaker 54 that the switching of the ACC mode is not possible.

[0045] <Example of operation of the embodiment> Next, referring to FIGS. 3 to 6, the operation of the embodiment will be described for various cases where the select switch 18A is operated in a situation where the ACC mode is the inter-vehicle distance control mode. In any case, affirmative determinations are made in steps S10 and S20.

[0046] <A. When the elapsed time T after the select switch 18A is operated is less than or equal to the reference time Tc> <a1>When your vehicle is not undergoing automatic deceleration due to automatic braking, and the distance between your vehicle and the vehicle in front exceeds the standard distance. Figure 3 shows a case where the vehicle 102 is not undergoing automatic deceleration due to automatic braking, and the distance L between the vehicle 102 and the preceding vehicle 110 exceeds the standard distance Lc. In this case, a negative determination is made in steps S40 to S60. Therefore, in step S70, the ACC mode is switched and set to constant speed driving control mode. In addition, the display 52 shows that the ACC mode is constant speed driving control mode.

[0047] <a2>If your vehicle is not undergoing automatic deceleration due to automatic braking, but the distance between your vehicle and the vehicle in front is below the standard distance. Figure 4 shows a case where vehicle 102 is not undergoing automatic deceleration due to automatic braking, but the distance L between vehicle 102 and the preceding vehicle 110 is less than or equal to the standard distance Lc. In this case, a negative determination is made in steps S40 and S50, but a positive determination is made in step S60. Therefore, in step S80, the display 52 and speaker 54 notify that it is not possible to switch the ACC mode. Note that the ACC mode will not be switched to the constant speed driving control mode.

[0048] <a3>When the host vehicle is automatically decelerating due to automatic braking FIG. 5 shows a case where a braking force Fb due to automatic braking acts on the host vehicle 102 and the host vehicle is automatically decelerating. In this case, a negative determination is made in step S40, but an affirmative determination is made in step S50. Therefore, similar to the case of A2 above, in step S80, it is notified by the display 52 and the speaker 54 that it is impossible to switch the ACC mode. Note that also in this case, the switching of the ACC mode to the constant speed running control mode is not performed.

[0049] <B. When the elapsed time T since the select switch was operated exceeds the reference time Tc> FIG. 6 shows a case where the elapsed time T since the select switch 18A was operated exceeds the reference time Tc. In this case, an affirmative determination is made in step S40. Therefore, similar to the case of A1 above, in step S70, the ACC mode is switched to and set to the constant speed running control mode. Further, it is displayed on the display 52 that the ACC mode is the constant speed running control mode.

[0050] Note that when the select switch 18A is operated in a situation where the ACC mode is the constant speed running control mode, an affirmative determination is made in step S10, but a negative determination is made in step S20. Therefore, in step S30, the ACC mode is switched to and set to the inter-vehicle distance control mode. Further, it is displayed on the display 52 that the ACC mode is the inter-vehicle distance control mode.

[0051] As can be seen from the above explanation, according to the embodiment, even if the select switch 18B is operated (S10), if the vehicle 102 is automatically decelerating or if the distance L between the vehicle and the preceding vehicle 110 is less than or equal to the reference distance Lc (S50, S60), the ACC mode cannot be switched to the constant speed driving control mode (S80). Therefore, since the vehicle speed V of the vehicle is controlled to become the target vehicle speed Vt, the vehicle does not relatively approach the preceding vehicle, thus preventing the distance between the vehicle and the preceding vehicle from becoming small and preventing the occupants from feeling uneasy as a result.

[0052] Furthermore, when the select switch 18B is operated while the vehicle 102 is not automatically decelerating and the distance L between the vehicle and the preceding vehicle 110 is not less than or equal to the standard distance Lc, the ACC mode is switched to constant speed driving control mode (S70). Therefore, the ACC mode can be switched from the distance control mode to the constant speed driving control mode according to the driver's preference.

[0053] Furthermore, according to this embodiment, the ACC mode is not switched to the constant speed driving control mode in either case when the vehicle 102 is automatically decelerating or when the distance L between the vehicle and the preceding vehicle 110 is less than or equal to the standard distance Lc. Therefore, compared to the case where the ACC mode is not switched to the constant speed driving control mode only when the vehicle is automatically decelerating or when the distance between the vehicle and the preceding vehicle 110 is less than or equal to the standard distance, it is possible to effectively prevent occupants from feeling uneasy.

[0054] In particular, according to the embodiment, when the select switch 18B is operated while the ACC mode is in the inter-vehicle distance control mode (S10, S20), it is determined whether the conditions are met such that the vehicle 102 has been automatically decelerated for a predetermined time Tc or that the inter-vehicle distance L between the vehicle and the preceding vehicle 110 is less than or equal to the reference inter-vehicle distance Lc (S50, S6). If it is determined that the conditions are met, the ACC mode is not switched to the constant speed driving control mode (S80).

[0055] Therefore, it is possible to prevent the ACC mode from switching to the constant speed driving control mode for a predetermined time Tc after the select switch 18B is operated, thereby preventing the occupants from feeling uneasy. Also, if a time exceeding the predetermined time Tc has elapsed since the select switch 18B was operated, the ACC mode will switch to the constant speed driving control mode. Therefore, it is possible to prevent the ACC mode from remaining in the constant speed driving control mode for an excessive amount of time.

[0056] When the ACC mode is in the distance control mode, operating the select switch 18B switches the ACC mode to the constant speed driving control mode, and the speed at which the vehicle approaches the preceding vehicle increases as the vehicle speed increases. Therefore, it is preferable that the time for which the ACC mode is delayed before switching to the constant speed driving control mode is longer as the vehicle speed increases.

[0057] According to the embodiment, the reference time Tc in the determination in step S40 is set variably according to the vehicle speed such that it increases as the vehicle speed V of the vehicle increases. Therefore, the higher the vehicle speed, the longer the time during which the switching of the ACC mode to the constant speed driving control mode is postponed.

[0058] When the ACC mode is in the distance control mode, operating the select switch 18B switches the ACC mode to the constant speed driving control mode, causing the vehicle to approach the preceding vehicle and reducing the distance between them. The speed at which this occurs increases with higher vehicle speed. Therefore, it is preferable that the distance at which the ACC mode is reserved for switching to the constant speed driving control mode is larger with higher vehicle speed.

[0059] According to the embodiment, the reference inter-vehicle distance Lc in the determination in step S60 is variably set according to the vehicle speed such that it increases as the vehicle speed V increases. Therefore, the higher the vehicle speed, the larger the inter-vehicle distance at which the ACC mode is reserved from switching to the constant speed driving control mode.

[0060] Although the present invention has been described in detail above with respect to specific embodiments, it will be apparent to those skilled in the art that the present invention is not limited to the embodiments described above, and that various other embodiments are possible within the scope of the present invention.

[0061] For example, in the embodiment described above, in step S10, it is determined whether or not the select switch 18A has been operated, and if a positive determination is made, in step S20, it is determined whether or not the ACC mode is the inter-vehicle distance control mode. However, the determination in step S20 may be performed first, and if a positive determination is made, the determination in step S10 may be performed.

[0062] In the above modified example, if a negative determination is made in step 20, control proceeds to step S30. Also, if a negative determination is made in step S10, control proceeds to step S30, and if a positive determination is made, control proceeds to step S40.

[0063] In this embodiment, in step S50, it is determined whether or not the vehicle 102 is undergoing automatic deceleration due to automatic braking, and then in step S60, it is determined whether or not the distance L between the vehicle 102 and the preceding vehicle is less than or equal to the reference distance Lc. However, the determination in step S60 may be performed first, and then the determination in step S50 may be performed. [Explanation of Symbols]

[0064] 10…Driver assistance ECU, 12…Camera sensor, 14…Radar sensor, 15…Target information acquisition device, 16…Switch, 22…Drive system, 32…Braking system, 36…Automatic braking system, 100…Driving control device, 102…Vehicle, 110…Preceding vehicle

Claims

[Claim 1] In a vehicle driving control device equipped with a control unit that switches the control mode between a constant speed driving control mode and a distance control mode when a control mode switching switch is operated, The control unit is configured such that, even when the control mode switch is operated while the control mode is the inter-vehicle distance control mode, the control mode is not switched to the constant speed driving control mode when the vehicle is automatically decelerating or when the distance between the vehicle and the preceding vehicle is less than or equal to the reference inter-vehicle distance.

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