Vehicle driving assistance systems

Abstract

The level of driver assistance is changed according to the driver's condition. [Solution] A vehicle driving support device including a control unit configured to perform at least one of the following: speed control, which controls the vehicle speed so as not to exceed a set speed Vset set by the driver; and distance control, which controls the distance between the vehicle and the preceding vehicle so as not to fall below a set distance Lset set by the driver. The control unit determines the driver's reaction speed Rv to surrounding events while the driver is driving the vehicle, and for speed control, the slower the reaction speed, the lower the set speed Vset (S130, S140). For distance control, the slower the reaction speed, the higher the set distance Lset (S150, S160).

Description

Technical Field

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

Background Art

[0002] As one of the driving support devices for vehicles such as automobiles, a driving support device that changes the level of driving support according to the driver's state is known. For example, in Patent Document 1 below, a driving support device is described that acquires at least one of the inspection results of the driver's field of view and reaction speed, and changes the level of driving support accordingly when at least one of the field of view and reaction speed is abnormal.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

[0004] 〔Problems to be Solved by the Invention〕 As driving support control, there are known vehicle speed control for controlling the vehicle speed so as not to exceed the set vehicle speed set by the driver, and inter-vehicle distance control for controlling the inter-vehicle distance between the host vehicle and the preceding vehicle so as not to be less than the set inter-vehicle distance set by the driver. The set vehicle speed and the set inter-vehicle distance are set by the driver within a predetermined vehicle speed range and a predetermined inter-vehicle distance range assumed for a driver with general driving ability.

[0005] However, even if the driver is normal, the reaction speed to surrounding events varies depending on the driver. Therefore, for a driver with a slow reaction speed, the upper limit of the predetermined vehicle speed range may be too high, or the lower limit of the predetermined inter-vehicle distance range may be too small.

[0006] The present invention provides a driver assistance device that performs at least one of vehicle speed control and inter-vehicle distance control, and is improved to automatically limit the settable range of the set vehicle speed and set inter-vehicle distance according to the driver's reaction speed.

[0007] [Means for solving the problem and the effects of the invention] According to the present invention, a vehicle driving assistance device (100) is provided, which includes a control unit (10) configured to perform at least one of the following: speed control, which controls the vehicle speed so as not to exceed a set vehicle speed (Vset) set by the driver; and distance control, which controls the distance between the vehicle (102) and the preceding vehicle so as not to fall below a set distance (Lset) set by the driver.

[0008] The control unit (10) determines the driver's reaction speed (Rv) to surrounding events while the driver is operating the vehicle, and is configured to limit the set vehicle speed (Vset) to a lower value the slower the reaction speed (S130, S140) for vehicle speed control, and to limit the set inter-vehicle distance (Lset) to a higher value the slower the reaction speed (S150, S160) for inter-vehicle distance control.

[0009] According to the above configuration, the driver's reaction speed to surrounding events while driving their vehicle is determined. For vehicle speed control, the slower the reaction speed, the lower the set vehicle speed value is restricted, and for inter-vehicle distance control, the slower the reaction speed, the higher the set inter-vehicle distance value is restricted.

[0010] Therefore, with regard to vehicle speed control, the slower the driver's reaction time, the lower the set vehicle speed will be restricted to, thus reducing the risk that the upper limit of the vehicle speed range that can be set to the set vehicle speed will be too high for drivers with slow reaction times. Similarly, with regard to following distance control, the slower the driver's reaction time, the higher the set following distance will be restricted to, thus reducing the risk that the lower limit of the following distance range that can be set to the set vehicle distance will be too low for drivers with slow reaction times. Consequently, vehicle speed control and / or following distance control can be safely performed even when the driver's reaction time is slow.

[0011] In the above description, 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]

[0012] [Figure 1] This is a schematic diagram showing a vehicle driver assistance device according to an embodiment. [Figure 2] This is a flowchart showing the driver reaction rate (Rv) acquisition control routine in the embodiment. [Figure 3] This flowchart shows the control routine for limiting the set speed and set distance between vehicles in the ACC (Adaptive Cruise Control) embodiment. [Modes for carrying out the invention]

[0013] Embodiments of the present invention will be described in detail below with reference to the attached figures.

[0014] As shown in Figure 1, the driver assistance device 100 according to an embodiment of the present invention is applied to a vehicle 102 and includes a driver assistance ECU 10. The vehicle 102 is a vehicle capable of autonomous driving and is equipped with a drive ECU 20, a brake ECU 30, an electric power steering ECU 40, and a meter ECU 50. ECU stands for Electronic Control Unit, which has a microcomputer as its main component. In the following description, electric power steering will be referred to as EPS, and the vehicle 102 will be referred to as the vehicle 102 as needed.

[0015] Each ECU's microcomputer includes a CPU, ROM, RAM, read / write non-volatile memory (N / M), and an interface (I / F). The CPU implements various functions by executing instructions (programs, routines) stored in ROM. Furthermore, these ECUs are interconnected via CAN (Controller Area Network) 104, enabling data exchange (communication). Therefore, detection values ​​from sensors (including switches) connected to a specific ECU are transmitted to other ECUs.

[0016] The driver assistance ECU 10 is a central control unit that performs driver assistance controls such as adaptive cruise control (ACC) and deceleration support control. Adaptive cruise control, abbreviated as ACC, includes two types of control: constant speed driving control and preceding vehicle following control. In the embodiment, the driver assistance ECU 10 works in cooperation with other ECUs to perform ACC and other functions, as will be described in detail later.

[0017] Constant speed driving control is a control that adjusts the vehicle speed of vehicle 102 so that it does not exceed the set speed (target speed) Vset or so that it matches the set speed, without requiring any braking or driving operations by the driver. Preceding vehicle following control is a control that makes the vehicle follow the preceding vehicle so that the distance between the preceding vehicle and the vehicle 102A does not fall below the set target distance Dset or so that the distance between the vehicle and the vehicle 102A does not fall below the set target distance.

[0018] The driver assistance ECU 10 is connected to a camera sensor 12, a radar sensor 14, a monitor camera 16, and a setting control unit 18. The camera sensor 12 and radar sensor 14 each include multiple camera devices and multiple radar devices, respectively. The camera sensor 12 and radar sensor 14 function as an object detection device 15 that detects objects around the vehicle 102. These objects include white lines, road signs and markings, traffic lights, stopped vehicles, and preceding vehicles.

[0019] Each camera device of the camera sensor 12, although not shown in the figure, includes a camera unit that photographs the area around the vehicle 102 and a recognition unit that analyzes the image data obtained from the camera unit to recognize road markings, other vehicles, and other objects. The recognition unit supplies information about the recognized objects to the driver assistance ECU 10 at predetermined intervals.

[0020] Each radar device in the radar sensor 14 uses millimeter-wave radio waves to detect the distance between the vehicle and a three-dimensional object, the relative speed between the vehicle and the three-dimensional object, and the relative position (direction) of the three-dimensional object relative to the vehicle, and supplies this information to the driver assistance ECU 10 at predetermined intervals. Alternatively, LiDAR (Light Detection And Ranging) may be used instead of, or in addition to, the radar sensor 14.

[0021] The monitor camera 16 is provided on the dashboard or the steering column, and includes a camera unit that captures the driver's face, and an image processing unit that processes the image data of the driver's face obtained by the camera unit. The monitor camera 16 functions as a driver monitor camera. The CPU of the driving support ECU 10 identifies the driver based on the information of the image data of the driver's face.

[0022] The setting operator 18 is provided at a position operable by the driver and is configured to be operated by the driver. Although not shown in FIG. 1, the setting operator 18 includes an ACC switch, a set speed setter, and a set target vehicle distance setter. The driving support ECU 10 executes ACC, that is, constant speed driving control and following vehicle control, when the ACC switch is on. The set speed setter and the set target vehicle distance setter may include setters that are displayed on the display 52 described later and operated by the driver's touch device.

[0023] A drive device 22 that accelerates the vehicle 102 by applying a driving force to the drive wheels 24 is connected to the drive ECU 20. Normally, the drive ECU 20 controls the drive device 22 so that the driving force generated by the drive device 22 changes according to the driving operation by the driver, and when receiving a command signal from the driving support ECU 10, controls the drive device 22 based on the command signal.

[0024] A braking device 32 that decelerates the vehicle 102 by applying a braking force to the wheels 34 is connected to the braking ECU 30. Normally, the braking ECU 30 controls the braking device so that the braking force generated by the braking device 32 changes according to the braking operation by the driver, and when receiving a command signal from the driving support ECU 10, performs automatic braking by controlling the braking device 32 based on the command signal. Note that the wheels 34 include the drive wheels 24. Therefore, the braking ECU 30 and the braking device 32 cooperate with each other to function as an automatic braking device.

[0025] An EPS device 42 is connected to the EPS / ECU 40. Based on the steering torque and vehicle speed detected by the driving operation sensor 60 and vehicle condition sensor 70 (described later), the EPS / ECU 40 controls the steering assist torque in a manner known in the art, thereby reducing the driver's steering burden. Furthermore, by controlling the EPS device 42, the EPS / ECU 40 can steer the steering wheels 44 as needed. Therefore, the EPS / ECU 40 and the EPS device 42 function as an automatic steering system that automatically steers the steering wheels as needed. Note that the steering wheels 44 are part of the wheels 34 and may also be drive wheels 24.

[0026] The meter ECU 50 is connected to a touch-panel display 52 and a speaker 54, which display the control status of the driver assistance ECU 10. The display 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 52 receives a signal from the driver assistance ECU 10, it may display the control status, such as ACC. The display 52 also displays visual warnings, and the speaker 54 emits audible warnings. Therefore, the display 52 and speaker 54 function as a notification device 56 that informs the driver of warnings and other information.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] The ROM of the driver assistance ECU 10 stores a program for controlling the acquisition of the driver's reaction speed Rv, corresponding to the flowchart shown in Figure 2. The ROM of the driver assistance ECU 10 also stores a program for limiting the ACC's set speed and target distance, corresponding to the flowchart shown in Figure 3.

[0031] <Control for acquiring driver reaction speed Rv (Figure 2)> Next, the driver reaction rate Rv acquisition control in the embodiment will be described with reference to the flowchart shown in Figure 2. The driver reaction rate Rv acquisition control according to the flowchart shown in Figure 2 is repeatedly executed at predetermined intervals by the CPU of the driver assistance ECU 10.

[0032] First, in step S10, the CPU identifies the driver based on the image data of the driver's face captured by the monitor camera 16. The driver may also be identified by an ID card or the like. In step S20, the CPU determines whether the vehicle 102 is in motion, for example, by checking whether the vehicle speed V is equal to or greater than a reference value (a positive constant). If a negative determination is made, the control proceeds to step S60; if a positive determination is made, the control proceeds to step S30.

[0033] In step S30, the CPU determines whether a specific pre-set event has occurred. If the determination is negative, the control returns to step S20; if the determination is positive, the control proceeds to step S40. The specific event may be, for example, the brake lights of a preceding vehicle turning on, the traffic light ahead changing from green to yellow, a bicycle or other vehicle suddenly appearing from a side street, or another vehicle crossing and passing through an intersection ahead without traffic lights.

[0034] In step S40, the CPU calculates the driver's reaction speed Rv to the occurrence of a predetermined specific event. For example, the longer the time between an event requiring braking, such as the brake lights of a preceding vehicle turning on, and the driver starting to brake, or the longer the time between an event requiring evasive steering, such as a sudden appearance of a vehicle, and the driver starting to steer, the slower the reaction speed Rv is calculated.

[0035] In step S50, the CPU stores the reaction rate Rv calculated in step S40 in RAM for the driver identified in step S10.

[0036] In step S60, the CPU determines whether the vehicle 102 has finished driving by determining, for example, whether the ignition switch (not shown in Figure 1) has changed from on to off. If a negative determination is made, the control returns to step S20; if a positive determination is made, the control proceeds to step S70. Note that even if the ignition switch is switched from on to off, power to the driver assistance ECU 10 continues for a predetermined period of time.

[0037] In step S70, the CPU updates the reaction speed Rv of the driver stored in the RAM. For example, when a stop line is detected ahead of the vehicle, the reaction speed is updated so that the reaction speed Rv increases as the deceleration when stopping the vehicle is lower when the vehicle needs to stop. Also, the variance value of the inter-vehicle distance is obtained for each vehicle speed, and the reaction speed is updated so that the reaction speed Rv increases as the variance of the inter-vehicle distance becomes smaller. Further, the variance values of the longitudinal acceleration and lateral acceleration of the vehicle 102 are obtained, and the reaction speed is updated so that the reaction speed Rv increases as these variances become smaller.

[0038] In step S80, the CPU stores the reaction speed Rv updated in step S70 in the non-volatile memory for the driver specified in step S10.

[0039] <ACC Setting Speed and Setting Target Inter-vehicle Distance Limiting Control (Figure 3)> Next, the ACC setting speed and setting target inter-vehicle distance limiting control in the embodiment will be described with reference to the flowchart shown in FIG. 3. The ACC setting speed and setting target inter-vehicle distance limiting control according to the flowchart shown in FIG. 3 is repeatedly executed by the CPU of the driving support ECU 10 at predetermined time intervals in a situation where the ACC switch is on.

[0040] First, in step S110, the CPU identifies the driver based on the information of the image data of the driver's face captured by the monitor camera 16, similar to step S10.

[0041] In step S120, the CPU determines whether there is a reaction speed Rv stored in the non-volatile memory for the identified driver. When a negative determination is made, this control ends once, and when an affirmative determination is made, this control proceeds to step S130. Therefore, when the reaction speed Rv is not stored in the non-volatile memory, the limitation of the ACC setting speed Vset by the limited vehicle speed Vlim and the limitation of the ACC setting inter-vehicle distance Lset by the limited inter-vehicle distance Llim, which will be described later, are not performed.

[0042] In step S130, the CPU sets the vehicle speed limit Vlim according to the reaction speed Rv such that the slower the reaction speed Rv, the lower the vehicle speed limit Vlim becomes, and displays the vehicle speed limit Vlim on the display 52.

[0043] In step S140, the CPU limits the ACC set speed Vset, which is set by the driver, to a speed less than or equal to the speed limit Vlim. For example, if the set speed Vset can be set to three speeds (high, medium, and low), the CPU may limit it by preventing it from being set to the high speed. Also, if the set speed Vset can be set within a range between an upper limit and a lower limit, the CPU may limit it by lowering the upper limit. Therefore, the driver cannot set the ACC set speed Vset to a speed higher than the speed limit Vlim.

[0044] In step S150, the CPU sets the limited distance Llim according to the reaction speed Rv such that the slower the reaction speed Rv, the larger the limited distance Llim becomes, and displays the limited distance Llim on the display 52.

[0045] In step S160, the CPU limits the ACC's set following distance Lset, which is set by the driver, to a distance greater than or equal to the restricted following distance Llim. For example, if the set following distance Lset is set to three distances—large, medium, and small—the restriction may be imposed by preventing it from being set to the small distance. Also, if the set following distance Lset is set within a range between an upper limit and a lower limit, the restriction may be imposed by raising the lower limit. Therefore, the driver cannot set the ACC's restricted following distance Lset to a distance smaller than the restricted following distance Llim.

[0046] As can be seen from the above explanation, the driver is identified based on the image data of the driver's face (S10), and when a specific event occurs while the vehicle 102 is in motion (S20, S30), the driver's reaction speed Rv is calculated and stored in RAM (S40, S50).

[0047] Furthermore, the driver is identified while ACC is running (S110). If there is a reaction speed Rv stored in non-volatile memory (S120), the vehicle speed limit Vlim is set according to the reaction speed Rv such that the slower the reaction speed Rv, the lower the vehicle speed limit Vlim (S130), and the ACC set vehicle speed Vset is limited to or less than the vehicle speed limit Vlim (S140). In addition, the vehicle distance limit Llim is set according to the reaction speed Rv such that the slower the reaction speed Rv, the larger the vehicle distance limit Llim (S1560), and the ACC set vehicle distance Lset is limited to or greater than the vehicle distance limit Llim (S160).

[0048] Therefore, according to the embodiment, with regard to vehicle speed control, the slower the driver's reaction speed Rv, the lower the set vehicle speed Vset is restricted to, thus reducing the risk that the upper limit of the vehicle speed range that can be set to the set vehicle speed will be too high for a driver with a slow reaction speed. Furthermore, with regard to inter-vehicle distance control, the slower the driver's reaction speed Rv, the higher the set inter-vehicle distance Lset is restricted to, thus reducing the risk that the lower limit of the inter-vehicle distance range that can be set to the set vehicle distance will be too low for a driver with a slow reaction speed. Consequently, vehicle speed control and inter-vehicle distance control can be safely performed even when the driver's reaction speed is slow.

[0049] Furthermore, according to the embodiment, in addition to the calculation of the reaction speed Rv in step S40, the update of the reaction speed Rv is performed in step S70. Therefore, since the reaction speed Rv is updated according to the variance values ​​of the longitudinal acceleration and lateral acceleration of the vehicle 102, the driver's reaction speed Rv can be determined more appropriately compared to the case where step S70 is not performed.

[0050] Furthermore, both the set distance Lset and the set distance Lset of the ACC are restricted. Therefore, compared to the case where only one of the set distance Lset or the set distance Lset is restricted, safety can be improved when the driver's reaction time Rv is low, as well as when the ACC is performing speed control and distance control.

[0051] 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.

[0052] For example, in the embodiment described above, both the ACC set following distance Lset and the set following distance Lset are restricted. However, the system may be modified so that only one of the set following distance Lset or the set following distance Lset is restricted.

[0053] Furthermore, in the above-described embodiment, in addition to the calculation of the reaction rate Rv in step S40, the update of the reaction rate Rv is performed in step S70. However, either the calculation of the reaction rate Rv or the update of the reaction rate Rv may be omitted.

[0054] Furthermore, in the above-described embodiment, the driver reaction speed Rv acquisition control (Figure 2) is performed regardless of whether or not driver assistance control is in operation. However, the driver reaction speed Rv acquisition control may be modified to be performed when driver assistance control is not in operation. [Explanation of Symbols]

[0055] 10...Driver assistance ECU, 16...Monitor camera, 18...Setting control unit, 102...Vehicle, 100...Driver assistance device

Claims

[Claim 1] A vehicle driving assistance system including a control unit configured to perform at least one of the following: speed control, which controls the vehicle speed so as not to exceed a set speed set by the driver; and distance control, which controls the distance between the vehicle and the preceding vehicle so as not to fall below a set distance set by the driver, The control unit is configured to determine the driver's reaction speed to surrounding events while the driver is operating the vehicle, to limit the set vehicle speed to a lower value as the reaction speed slows down, and to limit the set distance between vehicles to a higher value as the reaction speed slows down, in the case of vehicle speed control.

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