Driving assistance devices

Abstract

To realize efficient function integration to reduce the number of switches.SOLUTION: A driving assistance device installed in a vehicle, comprises: multiple first control units; and multiple second control units which provide a lower assistance level than that of the multiple first control units. The multiple first control units are activated when a first switch is operated, while the multiple second control units are activated when a second switch different from the first switch is operated.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a driving assistance device. [Background technology]

[0002] In recent years, efforts to provide access to sustainable transportation systems that take into consideration vulnerable traffic participants have become more active. To achieve this, we are focusing on research and development to further improve traffic safety and convenience through research and development on driver assistance. In this regard, Patent Documents 1 and 2 describe a configuration equipped with a cruise control switch and a variable speed limit control switch. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2017-047821 [Patent Document 2] Japanese Patent Application Laid-Open No. 2017-149229 Summary of the Invention [Problem to be solved by the invention]

[0004] In addition to adaptive cruise control and lane keeping control, other driving assistance controls being considered include deceleration control to maintain a safe distance from a preceding vehicle, and steering control with a lower degree of control than lane keeping control. As such, the number of types of driving assistance control is on an increasing trend, but providing a dedicated switch for each control raises concerns that the driver may not be able to get used to operating them. Conventional technology has not considered efficient functional unification to reduce the number of switches.

[0005] The present invention has been made in consideration of the above circumstances, and one of its objects is to provide a driving assistance device that can realize efficient functional integration to reduce the number of switches, thereby contributing to the development of a sustainable transportation system. [Means for solving the problem]

[0006] The driving assistance device according to the present invention employs the following configuration. (1): A driving assistance device according to one aspect of the present invention is a driving assistance device mounted on a vehicle, and includes a plurality of first control units each performing driving assistance control, and a plurality of second control units each performing driving assistance control, the plurality of second control units having an assistance level lower than that of the plurality of first control units; The plurality of first control units are activated by operating a first switch, and the plurality of second control units are activated by operating a second switch different from the first switch.

[0007] (2): In the above aspect (1), the plurality of first control units include both a control unit that performs longitudinal driving assistance control and a control unit that performs lateral driving assistance control, and the plurality of second control units include both a control unit that performs longitudinal driving assistance control and a control unit that performs lateral driving assistance control.

[0008] (3): A driving assistance device according to another aspect of the present invention is a driving assistance device mounted on a vehicle, and includes a plurality of first control units including both a control unit that performs longitudinal driving assistance control and a control unit that performs lateral driving assistance control, and a plurality of second control units including both a control unit that performs longitudinal driving assistance control and a control unit that performs lateral driving assistance control, wherein the plurality of first control units are activated by operating a first switch, and the plurality of second control units are activated by operating a second switch different from the first switch.

[0009] (4): In any of the above aspects (1) to (3), if the ignition switch of the vehicle is turned off while the plurality of first control units are activated, and then the ignition switch of the vehicle is turned on, the plurality of first control units do not automatically start up, and if the ignition switch of the vehicle is turned off while the plurality of second control units are activated, and then the ignition switch of the vehicle is turned on, the plurality of second control units automatically start up.

[0010] (5): In any of the above aspects (1) to (3), when the first switch is operated while the plurality of second control units are activated, the plurality of first control units are activated, and when the first switch is subsequently operated, the plurality of first control units are stopped and the plurality of second control units are activated.

[0011] (6): In any of the above aspects (1) to (3), one of the plurality of first control units performs follow-up driving control, another of the plurality of first control units performs lane keeping control, one of the plurality of second control units performs deceleration control to maintain a vehicle-to-vehicle distance from a preceding vehicle, and another of the plurality of second control units performs steering control with a lower degree of control than the lane keeping control.

[0012] (7): In any of the above aspects (1) to (3), the plurality of second control units include a speed limit control unit that is activated when a third switch capable of setting a speed is operated while other second control units are activated.

[0013] (8): In the above aspect (7), when the third switch is operated, an image prompting the driver to give consent is displayed on the display unit, and when the driver gives consent, the speed limit control unit is activated.

[0014] (9): In any of the above aspects (1) to (3), the plurality of second control units include a speed limit control unit that is activated when the legal speed limit of the road on which the vehicle is located is recognized while other second control units are activated.

[0015] (10): In the above aspect (9), when the plurality of second control units are activated and the legal speed limit of the road on which the vehicle is located is recognized, an image prompting the driver to accept the request is displayed on the display unit, and when the driver accepts the request, the speed limit control unit is activated. [Effects of the Invention]

[0016] According to aspects (1) to (10), it is possible to realize efficient functional unification to reduce the number of switches. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a diagram showing a part of the configuration of a vehicle M on which a driving assistance device 100 is mounted. [Figure 2] FIG. 2 is a state transition diagram of the driving assistance device 100. [Figure 3] 2 is a diagram illustrating an example of the configuration of a first switch 30, a second switch 32, and a third switch 34. FIG. [Figure 4] FIG. 2 is a diagram showing an example of a display screen of a display device 70. [Figure 5] FIG. 10 is a diagram showing another example of the display screen of the display device 70. DETAILED DESCRIPTION OF THE INVENTION

[0018] [composition] Hereinafter, an embodiment of a driving assistance device of the present invention will be described with reference to the drawings. Fig. 1 is a diagram showing a portion of the configuration of a vehicle M equipped with a driving assistance device 100. The vehicle M is equipped with external sensors such as a camera 10 and a radar device 12, vehicle sensors 14 such as a vehicle speed sensor and a yaw rate sensor, driving operators 20 such as an accelerator pedal, a brake pedal, and a steering wheel, a first switch 30, a second switch 32, and a third switch 34 for transmitting instructions to the driving assistance device 100, an ignition switch 40 for activating a driving force output device 200, a display device 70, and the like. The vehicle M is also equipped with devices for movement such as the driving force output device 200, a brake device 210, and a steering device 220.

[0019] The camera 10 is a digital camera that uses a solid-state imaging element such as a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor). The camera 10 is attached to any location on the vehicle M. When capturing an image of the front, the camera 10 is attached to the top of the front windshield, the back of the rearview mirror, or the like. The camera 10, for example, periodically and repeatedly captures images of the surroundings of the vehicle M. The camera 10 may be a stereo camera.

[0020] The radar device 12 emits radio waves such as millimeter waves around the vehicle M and detects radio waves reflected by objects (reflected waves) to detect at least the position (distance and direction) of the object. The radar device 12 is attached to any location on the vehicle M. The radar device 12 may detect the position and speed of an object using an FM-CW (Frequency Modulated Continuous Wave) method. The functions of the various switches will be described later. The display device 70 is provided, for example, on the instrument panel in front of the driver.

[0021] The driving force output device 200 outputs a driving force (torque) for the vehicle to travel to the driving wheels. The driving force output device 200 includes, for example, a combination of an internal combustion engine, an electric motor, a transmission, and the like, and an ECU (Electronic Control Unit) that controls these.

[0022] Braking device 210 includes, for example, a brake caliper, a cylinder that transmits hydraulic pressure to the brake caliper, an electric motor that generates hydraulic pressure in the cylinder, and a brake ECU. The brake ECU controls the electric motor so that brake torque is output to each wheel. Braking device 210 may include a backup mechanism that transmits hydraulic pressure generated by operation of a brake pedal included in driving operation element 20 to the cylinder via a master cylinder. Note that braking device 210 is not limited to the configuration described above, and may also be an electronically controlled hydraulic brake device.

[0023] The steering device 220 includes, for example, a steering ECU and an electric motor. The electric motor applies a force to, for example, a rack and pinion mechanism to change the direction of the steered wheels. The steering device 220 may further include a reaction motor for outputting a reaction force to the steering wheel. The steering ECU changes the direction of the steered wheels by driving the electric motor.

[0024] The driving assistance device 100 includes, for example, a following driving control unit 110, a lane keeping control unit 120, a cooperative deceleration control unit 130, a cooperative steering control unit 140, and a speed limit control unit 150. The following driving control unit 110 and the lane keeping control unit 120 are each an example of a "first control unit" that performs driving assistance control, and the cooperative deceleration control unit 130, the cooperative steering control unit 140, and the speed limit control unit 150 are each an example of a "second control unit" that performs driving assistance control. These control units are realized, for example, by a hardware processor such as a CPU (Central Processing Unit) executing a program (software). Some or all of these components may be realized by hardware (including circuitry) such as an LSI (Large Scale Integration), an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), or a GPU (Graphics Processing Unit), or may be realized by a combination of software and hardware. The program may be stored in advance in a storage device (a storage device with a non-transitory storage medium) such as an HDD (Hard Disk Drive) or flash memory, or may be stored in a removable storage medium (a non-transitory storage medium) such as a DVD or CD-ROM, and installed by inserting the storage medium into a drive device.

[0025] The follow-up running control unit 110 controls the driving force output device 200 and / or the braking device 210 to adjust the speed (both acceleration and deceleration) of the vehicle M so that the inter-vehicle distance between the preceding vehicle traveling immediately in front of the vehicle M and the vehicle M is maintained at a set inter-vehicle distance in the lane in which the vehicle M is located. The position of the preceding vehicle is recognized by analyzing images captured by the camera 10 or based on the output value of the radar device 12. If the preceding vehicle is not recognized within the effective distance, the follow-up running control unit 110 controls the driving force output device 200 and / or the braking device 210 so that the vehicle M travels at the set speed.

[0026] The lane keeping control unit 120 controls the steering device 220 to output a steering reaction force so that the vehicle M moves along the center of the lane in which the vehicle M is located, or to output a steering force in a direction that returns the vehicle M to the center of the lane when the vehicle M is about to deviate from the lane.

[0027] The cooperative deceleration control unit 130 controls the driving force output device 200 and / or the brake device 210 to solely decelerate the vehicle M so that the inter-vehicle distance between the preceding vehicle and vehicle M is maintained at a set inter-vehicle distance. If, for example, the preceding vehicle accelerates and moves away after deceleration, and the driver of vehicle M wishes to travel close to the preceding vehicle, the driver will operate the accelerator pedal himself to accelerate vehicle M.

[0028] The cooperative steering control unit 140 performs steering control that is looser than the lane keeping control unit 120 in order to prevent the vehicle M from deviating from its lane. "Loose" includes some or all of the following: a smaller control gain, a larger activation threshold (on the side where activation is less likely), a smaller upper limit value of control, etc. For example, the cooperative steering control unit 140 operates only when there is an obstacle (including a preceding vehicle) in the direction of travel of the vehicle M.

[0029] The speed limit control unit 150 controls the driving force output device 200 and / or the brake device 210 to decelerate the vehicle M when the speed of the vehicle M exceeds (or is likely to exceed) the upper speed limit.

[0030] The first switch 30 is used to simultaneously or sequentially activate the following cruise control unit 110 and the lane keeping control unit 120. The second switch 32 is used to simultaneously or sequentially activate the cooperative deceleration control unit 130 and the cooperative steering control unit 140, and also to conditionally activate the speed limit control unit 150. The set speed of the following cruise control unit 110 and the upper speed limit of the speed limit control unit 150 can both be adjusted by the third switch 34.

[0031] [state transition] 2 is a state transition diagram of the driving assistance device 100. As shown in the figure, the driving assistance device 100 can be in each of states 1 to 6. State 5 includes states 5-1 and 5-2.

[0032] State 1 is a state in which the ignition is off and the second control unit is not activated at the time the ignition is turned off. Whether or not the second control unit is activated at the time the ignition is turned off is stored in a non-volatile memory or the like, and each unit of the driving assistance device 100 operates by reading the stored information. When the ignition is turned on in State 1, the state transitions to State 2.

[0033] State 2 is a state in which neither the first control unit nor the second control unit is activated. If the ignition is turned off in State 2, the state transitions to State 1. If the first switch 30 is operated in State 2, the state transitions to State 3. Furthermore, if the second switch 32 is operated in State 2, the state transitions to State 5.

[0034] State 3 is a state in which the first control unit is activated and the second control unit is not activated at the time the first control unit is activated. If the brake pedal is operated by a predetermined amount or more in State 3, or if the first switch 30 is operated again, the state transitions to State 2. Note that if the second switch 32 is operated in State 3, the state may transition to State 5.

[0035] In state 4, the ignition is turned off and the second control unit was active at the time of turning off the ignition. If the ignition is turned on in state 4, the state transitions to state 5.

[0036] State 5 is a state in which the second control unit is activated (however, the speed limit control unit 150 may or may not be activated). State 5-1 is a state in which the speed limit control unit 150 is not activated. When transitioning to State 5 from State 2, 4, or 6, the state first transitions to State 5-1. In State 5-1, if the upper speed limit is set by operating the third switch 34, or if the legal speed is recognized by analyzing an image captured by the camera 10, and the driver approves it (described later), the state transitions to State 5-2. The legal speed may be recognized by image analysis, or by comparing map information with the position of the vehicle M measured by a GPS (Global Positioning System) receiver or the like, or by other communication means. State 5-2 is a state in which the speed limit control unit 150 is activated.

[0037] When the first switch 30 is operated in state 5, the state transitions to state 6. In state 6, the first control unit is activated and the second control unit was activated at the time the first control unit was activated. When the brake pedal is operated by a predetermined amount or more in state 6, or when the first switch 30 is operated again, the state transitions to state 5. Note that when the second switch 32 is operated in state 6, the state transitions to state 5.

[0038] Each control unit may be started spontaneously by its own built-in daemon program, or by a higher-level control unit that oversees the control units, which starts each control unit in response to switch operations. In the former case, the operation details of each switch are broadcast to each control unit via a multiplex communication network such as a CAN (Controller Area Network).

[0039] [Function Overview] In this way, the driving assistance device 100 includes a plurality of first control units and a plurality of second control units having a lower assistance level than the plurality of first control units. The plurality of first control units are activated by operating the first switch 30, and the plurality of second control units are activated by operating the second switch 32, which is different from the first switch 30. As a result, the plurality of first control units and the plurality of second control units having similar assistance levels are each assigned to separate switches and activated simultaneously, so that multiple controls constituting a driving level in line with the driver's intentions can be activated with a single switch operation. As a result, efficient functional unification can be achieved to reduce the number of switches.

[0040] Note that the meaning of "plurality of second control units having a lower assistance level than the plurality of first control units" here means that the degree of control is lower when, for example, comparing control units that perform longitudinal control (speed control) with control units that perform lateral control (steering control). For example, the cooperative deceleration control unit 130 and the speed limit control unit 150 are control units that exclusively perform deceleration, and therefore have a lower degree of control than the following cruise control unit 110, which performs both acceleration and deceleration. Also, the cooperative steering control unit 140 performs steering control that is looser than the lane keeping control unit 120, and can be said to have a lower degree of control than the lane keeping control unit 120.

[0041] Furthermore, the multiple first control units include both a control unit that performs longitudinal control (speed control) and a control unit that performs lateral control (steering control), and similarly, the multiple second control units include both a control unit that performs longitudinal control (speed control) and a control unit that performs lateral control (steering control). This allows multiple control units that perform controls that do not conflict with each other to be activated approximately simultaneously, making it possible to switch between controls with high validity.

[0042] Furthermore, if the ignition switch 40 of the vehicle M is turned off while the multiple first control units are activated and then turned on, the multiple first control units do not automatically activate (state 1 → 2 or state 4 → 5 in FIG. 2 ). However, if the ignition switch 40 of the vehicle M is turned off while the multiple second control units are activated and then turned on (state 5 → 4 → 5), the multiple second control units automatically activate. This eliminates the need for the driver to operate the second control units again, reducing inconvenience. Note that, because the assistance level of the first control units is high, unexpected situations may occur if they were automatically activated from the start of the vehicle M. Therefore, they are not automatically activated when the ignition switch 40 is turned on. As a result, a smooth start of the vehicle M can be achieved.

[0043] Furthermore, when the first switch 30 is operated while the plurality of second control units are activated, the plurality of first control units are activated, and when the first switch 30 is subsequently operated (state 5 → 6 → 5), the plurality of first control units are stopped and the plurality of second control units are activated. As a result, when the plurality of second control units are activated, it is possible to switch between a state in which the plurality of first control units are activated and a state in which the plurality of second control units are activated simply by operating the first switch 30, thereby simplifying the operation by the occupant.

[0044] Furthermore, one of the multiple first control units is a follow-up driving control unit 110 that performs follow-up driving control, another of the multiple first control units is a lane keeping control unit 120 that performs lane keeping control, one of the multiple second control units is a cooperative deceleration control unit 130 that performs deceleration control to maintain a vehicle-to-vehicle distance from a preceding vehicle, and another of the multiple second control units is a cooperative deceleration control unit 130 that performs steering control with a lower degree of control than the lane keeping control unit 120. As a result, the multiple first control units with a high assistance level are turned off without retaining their previous activation state, while the multiple second control units with a lower assistance level than the follow-up driving control unit 110 and the lane keeping control unit 120 and that provide assistance to enhance occupant peace of mind in cooperation with occupant operation are turned on with their previous activation state. This makes it possible to prevent dangerous situations before they occur at an earlier timing than collision avoidance or departure prevention. As a result, it is possible to actively turn on assistance that enhances occupant peace of mind while suppressing excessive assistance.

[0045] [Switch type and display screen] FIG. 3 illustrates an example configuration of the first switch 30, the second switch 32, and the third switch 34. The first switch 30, the second switch 32, and the third switch 34 are, for example, arranged together on either the left or right side of the boss portion of the steering wheel 22, allowing the driver to operate them with one hand. The first switch 30 and the second switch 32 are each a switch that can be operated by, for example, a push or tap, and the switch itself does not have a state retention function. The first switch 30 and the second switch 32 may each be a mechanical switch or a touch panel switch. The third switch 34 is located between the first switch 30 and the second switch 32, allowing the driver to roughly recognize their positions by touch without visually checking them. The third switch 34 can, for example, be operated by rotating a cylindrical wheel portion up and down to approximately continuously increase and decrease a set value. By operating the third switch 34, the driver can adjust the set speed in the follow-up driving control unit 110 and the upper speed limit in the speed limit control unit 150 up or down in increments of, for example, 5 km / h. Note that the follow-up driving control unit 110 and the speed limit control unit 150 do not start up at the same time, so that the adjustments of the values ​​do not conflict with each other.

[0046] 4 is a diagram showing an example of the display screen of the display device 70. The display screen of the display device 70 is divided into, for example, areas 70A, 70B, and 70C. In a state where the plurality of first control units are not activated (state 2 or 5), the speed of the vehicle M is displayed in the form of a speedometer in the area 70A. In state 5-1, characters and an object (represented by "AAA" in the figure) indicating that the coordinated deceleration control unit 130 and the coordinated steering control unit 140 are activated are displayed in the area 70B. In state 5-2, characters and an object (represented by "BBB" in the figure) indicating that the speed limit control unit 150 is activated are also displayed in the area 70B.

[0047] In state 5-1, when the upper speed limit is set by operating the third switch 34, or when the legal speed limit is recognized by analyzing the image captured by the camera 10, an image prompting the driver to consent to the activation of the speed limit control unit 150 is displayed in the area 70C. In response, when the driver consents, the speed limit control unit 150 is activated. This consent is performed, for example, on the second switch 32.

[0048] FIG. 5 is a diagram showing another example of the display screen of the display device 70. This diagram illustrates an example of the display screen when multiple first control units are activated. In this case, an object indicating the detailed operating state of each of the first control units is displayed in each area. The display device 70 is controlled by a display control unit (not shown) of the driving assistance device 100 so as to display the state of either the multiple first control units or the multiple second control units. This makes it possible to present necessary information to the driver without increasing the display screen.

[0049] The multiple second control units include a speed limit control unit 150 that is activated through a driver's consent operation when the third switch 34 capable of setting a speed is operated while other second control units are activated, or when the legal speed limit of the road on which the vehicle M is located is recognized. This prevents the speed limit control unit 150 from being activated when the speed setting is unknown, and also prevents the number of switches from increasing because the second switch 32 receives a consent operation.

[0050] According to the embodiment described above, it is possible to realize efficient functional unification to reduce the number of switches.

[0051] [About implementation] The above-described first control units and second control units can be referred to as a plurality of first control devices and a plurality of second control devices, respectively, if they are realized by dedicated processors. Furthermore, the first control units and second control units can be referred to as a plurality of first programs and a plurality of second programs, respectively, regardless of whether they are realized by dedicated processors.

[0052] The above-described embodiment can be expressed as follows. each of which comprises a storage medium storing computer-readable instructions; a plurality of first control devices each including a processor connected to the storage medium; each of which stores computer-readable instructions; a plurality of second control devices each including a processor connected to the storage medium; Equipped with the plurality of second control devices perform control with a lower support level than the plurality of first control devices, the plurality of first control devices are activated by operation of a first switch, The plurality of second control devices are activated by operating a second switch different from the first switch. For example, the plurality of first control devices include an adaptive cruise control device and a lane keeping control device, and the plurality of second control devices include a cooperative deceleration control device, a cooperative steering control device, and a speed limit control device.

[0053] The above-described embodiment can also be expressed as follows. a storage medium storing computer readable instructions; a processor connected to the storage medium; the storage medium stores a plurality of first programs, each including a plurality of instructions, and a plurality of second programs, each including a plurality of instructions; By executing each of the plurality of first programs, driving assistance control is performed, By executing the plurality of second programs, driving assistance control is performed at a lower assistance level than when the plurality of first programs are executed, the plurality of first programs are activated by operating a first switch, The plurality of second programs are activated when a second switch different from the first switch is operated. For example, the plurality of first programs include a following cruise control program and a lane keeping control program, and the plurality of second programs include a cooperative deceleration control program, a cooperative steering control program, and a speed limit control program.

[0054] The above describes the form for carrying out the present invention using an embodiment, but the present invention is not limited to such an embodiment, and various modifications and substitutions can be made within the scope that does not deviate from the gist of the present invention. [Explanation of symbols]

[0055] 30 First Switch 32 Second Switch 34 Third Switch 70 Display device 100 Driving assistance device 110 Following driving control unit 120 Lane keeping control unit 130 Cooperative deceleration control unit 140 Cooperative steering control unit 150 Speed ​​limit control unit

Claims

1. A driving assistance device mounted on a vehicle, a plurality of first control units each performing driving assistance control; a plurality of second control units each performing driving assistance control, the second control units having an assistance level lower than that of the plurality of first control units; Equipped with the plurality of first control units are activated by operation of a first switch, the plurality of second control units are activated by operating a second switch different from the first switch, When an ignition switch of the vehicle is turned off while the plurality of first control units are activated, and then the ignition switch of the vehicle is turned on, the plurality of first control units do not automatically activate, When an ignition switch of the vehicle is turned off with the plurality of second control units activated, and then the ignition switch of the vehicle is turned on, the plurality of second control units are automatically activated. Driving assistance device.

2. A driving assistance device mounted on a vehicle, a plurality of first control units each performing driving assistance control; a plurality of second control units each performing driving assistance control, the second control units having an assistance level lower than that of the plurality of first control units; Equipped with the plurality of first control units are activated by operation of a first switch, the plurality of second control units are activated by operating a second switch different from the first switch, When the first switch is operated in a state in which the plurality of second control units are activated, the plurality of first control units are activated, and when the first switch is subsequently operated or a brake operation of a predetermined amount or more is performed on a brake pedal of the vehicle, the plurality of first control units are stopped and the plurality of second control units are activated. Driving assistance device.

3. the plurality of first control units include both a control unit that performs longitudinal driving assistance control and a control unit that performs lateral driving assistance control, The plurality of second control units include both a control unit that performs longitudinal driving assistance control and a control unit that performs lateral driving assistance control, The driving assistance device according to claim 1 or 2.

4. One of the plurality of first control units performs follow-up running control, Another one of the plurality of first control units performs lane keeping control, One of the plurality of second control units performs deceleration control to maintain a vehicle-to-vehicle distance from a preceding vehicle, Another one of the plurality of second control units performs steering control with a lower degree of control than the lane keeping control. The driving assistance device according to any one of claims 1 to 3.

5. The plurality of second control units include a speed limit control unit that is activated when a third switch capable of setting a speed is operated while other second control units are activated. The driving assistance device according to any one of claims 1 to 3.

6. When the third switch is operated, an image prompting the driver to accept the operation is displayed on a display unit, and when the driver accepts the operation, the speed limit control unit is activated. The driving assistance device according to any one of claims 5 to 7.

7. The plurality of second control units include a speed limit control unit that is activated when the legal speed limit of a road on which the vehicle is located is recognized while other second control units are activated. The driving assistance device according to any one of claims 1 to 3.

8. When the plurality of second control units are activated and the legal speed limit of the road on which the vehicle is located is recognized, an image prompting the driver to accept the speed limit is displayed on a display unit, and when the driver accepts the speed limit, the speed limit control unit is activated. The driving assistance device according to claim 7.

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