Driver assistance systems and vehicles

Abstract

To provide an operation support device and a vehicle which activate tracking travel control according to status of road surface of a general road such as snowy road and muddy road in addition to express way where road surface status is stable and according to operator's taste.SOLUTION: An operation support device 10 comprises: a travel mode determination part 11 which determines a travel mode according to selection of the travel mode by an operator of a vehicle 100; a traction control part 12 which suppresses slip of a driving wheel by controlling at least one of an engine 25 and a brake system 26 when slip amount of the driving wheel exceeds an intervention threshold based on a traction control condition regulated by each travel mode; and a tracking travel control part 15 which controls a tracking travel that tracks a preceding vehicle based on a tracking control condition regulated by each travel mode. The tracking travel control part 15 controls, when a travel mode is changed over, the tracking travel based on the tracking control condition regulated by a changed travel mode.SELECTED DRAWING: Figure 1

Description

Technical Field

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[0001] The present invention relates to a driving support technology for assisting acceleration and deceleration of a vehicle.

Background Art

[0002] Many vehicles manufactured in recent years are equipped with a follow - up driving control (ACC: Adaptive Cruise Control) function that automatically accelerates and decelerates the vehicle within a preset vehicle speed to assist the driver in driving. ACC is activated by the driver's operation of turning on the ACC switch after ignition is started. Thereafter, ACC is activated by the driver's operation of turning on the ACC switch or by an accelerator operation during driving, and temporarily stops by a brake operation. The driving mode by ACC varies depending on the presence or absence of a preceding vehicle detected by various in - vehicle sensors. When a preceding vehicle is detected, the vehicle follows while maintaining a predetermined inter - vehicle distance from the preceding vehicle under the control of ACC. On the other hand, when no preceding vehicle is detected, the vehicle accelerates and decelerates to a preset vehicle speed and runs. Conventionally, ACC has been assumed to be used on exclusive automobile roads such as highways. Therefore, conventionally, the use of ACC has been recommended only when the driving mode is the normal mode suitable for driving on exclusive automobile roads.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in recent years, due to the progress of autonomous driving technology, the use of ACC on ordinary roads has also come to be assumed. Therefore, it has been required to make ACC compatible with road surface conditions such as snowy roads and muddy roads and driver preferences.

[0005] This invention was made in consideration of these circumstances, and aims to provide a driver assistance device and vehicle that activates follow-me driving control according to road conditions and driver preferences not only on highways with stable road conditions, but also on general roads such as snowy or muddy roads. [Means for solving the problem]

[0006] The driver assistance device according to this embodiment includes: a driving mode determination unit that determines a driving mode according to the driving mode selected by the driver of the vehicle; a traction control unit that controls at least one of the engine and brakes to suppress the slip of the drive wheels when the amount of slip of the drive wheels exceeds an intervention threshold, according to the traction control conditions defined for each driving mode; and a follow driving control unit that controls follow driving to follow a preceding vehicle according to the follow control conditions defined for each driving mode, wherein when the driving mode is switched, the follow driving control unit controls the follow driving by changing the follow control conditions defined for the driving mode after the switch. The driving mode includes a first mode in which at least one of the intervention threshold and traction control amount defined in the traction control conditions and at least one of the engine torque and brake force defined in the follow-up control conditions are all default values, and a selection mode having different traction control conditions than the first mode. The selection mode includes a second mode in which the intervention threshold for the brake force in the traction control conditions is defined to be smaller than in the first mode, and in the follow-up control conditions of the second mode, the amount of engine torque controlled at the time of starting is set lower than in the first mode, and the rate of increase of the engine torque when the vehicle speed exceeds a predetermined speed is set to be larger than in the first mode. Furthermore, the driver assistance device according to this embodiment includes: a driving mode determination unit that determines a driving mode according to the selection of a driving mode by the driver of the vehicle; a traction control unit that controls at least one of the engine and brakes to suppress slip of the drive wheels when the amount of slip of the drive wheels exceeds an intervention threshold, according to the traction control conditions defined for each driving mode; and a follow driving control unit that controls follow driving to follow a preceding vehicle according to the follow control conditions defined for each driving mode, wherein when the driving mode is switched, the follow driving control unit controls the follow driving by changing the follow control conditions defined for the switched driving mode. The driving mode includes a first mode in which at least one of the intervention threshold and traction control amount defined in the traction control conditions and at least one of the engine torque and brake force defined in the follow control conditions are all default values, and a selection mode having different traction control conditions from the first mode. The selected mode includes a third mode in which, in a vehicle speed range below a predetermined vehicle speed, the torque reduction of the engine by the traction control unit is suppressed or prohibited, and the brake force of the traction control conditions is set to be greater than that of the first mode, and in the follow control conditions of the third mode, the engine torque at startup is set to be greater than that of the first mode.

[0007] The vehicle according to this embodiment includes a driving mode switching switch operated by the driver of the vehicle to switch driving modes, a wheel sensor that monitors the rotation state of the wheels, a traction control unit that controls at least one of the engine and brakes to suppress slip of the drive wheels when the amount of slip of the drive wheels exceeds an intervention threshold, according to traction control conditions defined for each driving mode, a preceding vehicle detection unit that detects a preceding vehicle traveling in front of the vehicle, and the driver operates A follow-up driving start switch, and the operation of the follow-up driving start switch triggers, The system issues a command to initiate follow-up driving, which follows the preceding vehicle according to the follow-up control conditions defined for each of the aforementioned driving modes. Follow-up driving activation command unit and, After the aforementioned activation command When the aforementioned driving mode is switched 、 The system includes a follow-driving control unit that controls the follow-driving by changing the follow-driving conditions to those defined in the driving mode after switching. [Effects of the Invention]

[0008] The present invention provides a driver assistance system and vehicle that activates adaptive cruise control not only on highways with stable road conditions, but also on general roads such as snowy or muddy roads, in accordance with road conditions and the driver's preferences. [Brief explanation of the drawing]

[0009] [Figure 1] A schematic diagram of a vehicle equipped with a driver assistance system according to the embodiment. [Figure 2] A schematic diagram of the area around the instrument panel as seen from the driver's seat. [Figure 3] A diagram showing the ACC conditions and TCS conditions specified for each driving mode. [Figure 4] This diagram shows the relationship between time and engine torque in each driving mode. [Figure 5] A flowchart illustrating the methods by which the follow-me driving control unit activates and temporarily disables follow-me driving. [Modes for carrying out the invention]

[0010] Hereinafter, embodiments of the present invention will be described based on the attached drawings.

[0011] Figure 1 is a schematic diagram of a vehicle 100 equipped with a driver assistance device 10 according to an embodiment. The driver assistance device 10 is a type of automated driving system that assists the driver by performing adaptive cruise control (ACC) and traction control (TC) of the drive wheels in a timely manner for the vehicle 100. Driver assistance means that the automated driving system performs either steering of the vehicle 100 or acceleration / deceleration of the vehicle 100, including starting and stopping, in a limited and continuous manner.

[0012] The ACC function automatically accelerates and decelerates the vehicle 100 within a preset speed range, and if there is a vehicle ahead of the vehicle 100, it approaches the vehicle to a predetermined distance and maintains this distance while following it. This function allows the driver to operate the vehicle without pressing the accelerator or brake pedal except when necessary. Furthermore, the traction control function prevents slippage, such as wheel spin, by controlling the rotation of the drive wheels. This function ensures appropriate driving force and maneuverability in situations where drive wheel slippage is likely to occur.

[0013] The driver assistance system 10 will be described in detail below with reference to Figure 1. The driver assistance device 10 includes a driving mode determination unit 11, a brake ECU 13 equipped with a traction control unit (TC unit) 12, a follow driving activation command unit (ACC activation command unit) 14, a follow control unit (ACC unit) 15, an engine ECU 16, and a memory unit 17.

[0014] Furthermore, the driver assistance device 10 is connected to the driving mode switching switch 21, wheel speed sensor 22, follow control start switch (ACC start switch) 23, preceding vehicle detection unit 24, engine 25, and brake system 26 via the vehicle's in-vehicle network 20.

[0015] The driving mode determination unit 11 determines the driving mode selected by the driver's operation of the driving mode switching switch 21 as the driving mode to be executed by the driver assistance device 10. Here, FIG. 2 is a schematic view of the vicinity of the instrument panel 30 as seen from the driver's seat. On the front half of the top surface of the console box 31 that separates the driver's seat and the passenger seat, a console upper panel 33 for inserting the shift lever 32 is provided. For example, a dial-type or push-type driving mode switching switch 21 is provided on this console upper panel 33. The driver operates the driving mode switching switch 21 to switch the driving mode during driving or before starting driving after the ignition switch is turned ON. When a driving mode is selected, the selected driving mode is displayed on the meter panel 34 or the navigation panel 35 provided on the instrument panel 30.

[0016] The driving modes selectable by the driving mode selection function are, for example, the snow mode (second mode), the lock mode (third mode), and the sports mode (fourth mode). Also, the state in which none of these driving modes is selected is called the normal mode (first mode). Details of each driving mode will be described later.

[0017] Returning to FIG. 1, the description of the vehicle 100 and the driving support device 10 will be continued. The wheel speed sensor 22 monitors the rotational speed of the wheels and detects slips such as wheel spin of the drive wheels.

[0018] The brake ECU 13 suppresses drive wheel slip through the function of the TC unit 12 when the slip detected by the wheel speed sensor 22 exceeds a predetermined intervention threshold. The brake ECU 13 controls the brake system 26 and controls the engine 25 via the engine ECU 16. The brake ECU 13 suppresses drive wheel slip by performing at least one of the following: suppressing the engine torque of the engine 25 and activating the brakes of the brake system 26. ECU is an abbreviation for Electronic Control Unit, which consists of a CPU, ROM, and RAM. The engine ECU 16 electronically controls the output of the engine 25. Similarly, the brake ECU 13 electronically controls the operation of the brake system 26. The brake ECU 13 equipped with the TC unit 12 that performs traction control functions, the engine ECU 16, and the memory unit 17 that stores traction control conditions are collectively called a Traction Control System (TCS).

[0019] Traction control by the TC unit 12 is performed according to the TCS conditions defined for each driving mode. In addition to the control mode, the TCS conditions also define an intervention threshold that determines the timing of intervention by the TC unit 12, as appropriate for each driving mode.

[0020] The ACC activation command unit 14 triggers the driver pressing the ACC start switch 23 to send an activation command for follow control to the ACC unit 15. The ACC start switch 23 is located on the pillar portion 37a of the steering wheel 37, for example, as shown in Figure 2. When the driver wants to activate ACC, they press the ACC start switch 23 while driving or before starting to drive after turning on the ignition switch. Follow driving using ACC is started when the driving speed exceeds a preset vehicle speed threshold. This vehicle speed threshold may be set to 0 km / h. In this case, the ACC unit 15 also controls the starting and stopping of the vehicle 100.

[0021] The ACC unit 15 controls the engine 25 and brake system 26 via the engine ECU 16 and brake ECU 13, respectively, when the driving speed exceeds the vehicle speed threshold after an activation command is issued by the ACC activation command unit 14. The driving mode under ACC differs depending on whether or not there is a preceding vehicle detected by the preceding vehicle detection unit 24, which consists of a camera 24a and a millimeter-wave radar 24b.

[0022] As described above, when the preceding vehicle detection unit 24 detects a preceding vehicle in front of vehicle 100, vehicle 100 follows the preceding vehicle while maintaining a predetermined distance, under the ACC of the ACC unit 15. This distance can be changed by the driver in, for example, four stages using the sub-switch of the ACC start switch 23. This distance and the speed difference with the preceding vehicle are monitored by the preceding vehicle detection unit 24. On the other hand, when the preceding vehicle detection unit 24 does not detect a preceding vehicle in front of vehicle 100, the ACC unit 15 accelerates and decelerates to a predetermined set speed. This set speed can also be changed by the driver using the sub-switch of the ACC start switch 23.

[0023] In the driving assistance device 10 according to this embodiment, ACC conditions are set that define the ACC control mode according to each of the aforementioned driving modes. The ACC unit 15 controls follow-up driving according to these ACC conditions. Furthermore, if the driving mode is switched after the command to activate follow-up control is issued, the ACC unit 15 controls the vehicle 100 by changing to follow-up driving according to the ACC conditions defined in the new driving mode.

[0024] Furthermore, each component of the driver assistance system 10 can be configured as a computer equipped with a processor such as a CPU, a ROM (Read Only Memory), a RAM (Random Access Memory), or a storage device such as an HDD (Hard Disk Drive). In this case, the functions of the TC unit 12, the driving mode determination unit 11, the ACC activation command unit 14, and the ACC unit 15, among the components of the driving assistance device 10, can be realized by the processor executing a predetermined program stored in the memory device. Alternatively, this can be implemented using hardware such as ASICs (Application Specific Integration Circuits) or FPGAs (Field-Programmable Gate Arrays) instead of software.

[0025] Next, we will explain each driving mode using Figures 3 and 4. Figure 3 shows the ACC conditions and TCS conditions defined for each driving mode. Figure 4 shows the relationship between time and engine torque in each driving mode. As shown in Figures 1 and 3, the memory unit 17 stores TCS conditions and ACC conditions for each driving mode. The ACC conditions specify acceleration and deceleration controlled by the engine 25 and brake system 26, as well as the distance to the preceding vehicle and the timing of the control. The TCS conditions specify the amount of engine torque suppression for the engine 25 and the braking force, as well as the intervention timing. The intervention timing is defined by the intervention threshold, which is a threshold set for the slip amount. This slip amount threshold, i.e., the intervention threshold, is set for the respective slip amounts of engine control and brake control by the TCS.

[0026] The ACC unit 15 and the TC unit 12 control the engine 25 and the brake system 26 in conjunction with each other based on the TCS conditions and ACC conditions defined for the selected driving mode. As a result, the response of the engine 25 and the brake system 26 to the driver's driving operations when ACC and TCS are activated will differ for each driving mode. The TCS conditions and ACC conditions may be stored in a memory device (not shown) within the brake ECU 13, for example. In other words, the memory unit 17 may be located anywhere within the driver assistance device 10.

[0027] [Normal Mode (Mode 1)] Normal mode is a driving mode suitable for driving on dry, paved roads. As mentioned above, normal mode is the default driving mode when the driver does not select a driving mode. Because it is a driving mode intended for highways and other expressways, it has traditionally been considered a suitable driving mode for activating ACC.

[0028] In normal mode, the intervention timing by TCS, i.e., at least one of the intervention threshold and traction control amount, is defined as a TCS condition. In normal mode, each parameter within the TCS condition and ACC condition is set to a standard value (default value). In other words, as shown in Figure 3, the intervention threshold and traction control amount set for the slip amount in the TCS condition, as well as the engine torque and brake force in the ACC condition, are all set to their default values.

[0029] Furthermore, the TC unit 12 does not necessarily have to control both engine torque and brake force. In other words, the TC unit 12 may control traction using only one of either engine torque or brake force. Similarly, the ACC unit 15 may also control using only one of either engine torque or brake force. In Figure 4, the graph represented by the thick solid line is the graph for normal mode.

[0030] [Snow Mode (Second Mode)] Snow mode is a driving mode suitable for driving on slippery surfaces such as icy or snowy roads. In snow mode, it is especially important to prevent wheel slippage when starting. Therefore, in snow mode, as shown in Figure 3, the engine torque at startup is set lower than in normal mode under ACC conditions. Furthermore, once the vehicle speed increases to a level where the risk of slipping is sufficiently low, it is necessary to suppress the delay in following the preceding vehicle. Therefore, in ACC conditions, the rate of increase in engine torque when the vehicle speed exceeds a predetermined threshold is set to be greater than in normal mode.

[0031] As a result, in snow mode, the engine torque increases more gradually than in normal mode, as shown by the thin solid line in the graph in Figure 4, before suddenly increasing to the same level as other driving modes. In this way, the ACC unit 15 increases acceleration and strengthens the acceleration to follow the preceding vehicle when it determines that a stable speed can be obtained. Therefore, even drivers unfamiliar with driving on slippery surfaces can press the accelerator pedal firmly. Furthermore, even if the driver operates the accelerator themselves midway through, the vehicle starts from low engine torque, which helps to suppress wheel slip. In addition, in ACC mode, even without driver intervention, the jerk is increased when the vehicle 100 reaches a certain stable speed, improving the ability to follow the preceding vehicle.

[0032] Furthermore, collisions with the vehicle ahead are more likely to occur on slippery surfaces. Therefore, in Snow Mode, the distance between vehicle 100 and the vehicle ahead is set to be greater than in Normal Mode under ACC conditions. Also, for the same reason, the timing of the brake system 26's activation under ACC conditions is set to be earlier than in Normal Mode. In Snow Mode, it is assumed that when the driver operates the accelerator themselves, they may press the accelerator pedal harder, trusting the traction control function in Snow Mode. In this case, even if ACC stops and vehicle 100 accelerates more than expected, safety is ensured because the distance to the vehicle ahead is set to be wider.

[0033] Similarly, taking into account slippery road surfaces, the intervention threshold set for the amount of slip in the TCS conditions is defined to be smaller than the default value. As a result, the TC unit 12 can detect even slight wheel slip and activate the TCS early. Therefore, the driver can drive even on slippery road surfaces without a decrease in driving force and maneuverability due to slippage.

[0034] Furthermore, the snow mode may be automatically switched on without the driver having to press the driving mode switching switch 21. For example, the driving mode determination unit 11 may automatically switch to snow mode when the road surface μ value is low after road surface μ estimation. As described above, by setting the ACC and TCS conditions to match the snow mode, the driver can drive safely even on slippery roads.

[0035] [Lock Mode (Third Mode)] Lock mode (the third mode) is a driving mode suitable for getting the vehicle out of a jam, such as being stuck in mud, sand, or snow. In lock mode, the braking force provided by the traction control system (TC) unit 12 is set to be greater than the default value in normal mode. Furthermore, in vehicle speed ranges below a predetermined speed, the torque reduction of the engine 25 by the TC unit 12 is suppressed or prohibited. In lock mode, the increased braking force from the traction control system (TCS) and the resulting high engine torque provide superior escape from being stuck.

[0036] Furthermore, under ACC conditions, the engine torque at startup is set higher than the default value in normal mode. By setting the engine torque higher than the default value at startup, slip detection is accelerated even when ACC is active, allowing for earlier brake application. However, to prevent sudden acceleration when escaping from rough terrain, the engine torque in lock mode is set lower than in sport mode. In particular, as shown by the thick dashed line in the graph in Figure 4, the engine torque in lock mode when ACC is active at startup is set lower than in sport mode. Preventing sudden acceleration when escaping from rough terrain helps to alleviate driver anxiety.

[0037] Furthermore, under ACC conditions, if a vehicle gets stuck while ACC is activated in lock mode, it is desirable to set the engine torque to increase gradually. This is to prevent the driver from experiencing a sudden acceleration, even if they have selected lock mode when the vehicle is not stuck at all.

[0038] Furthermore, if the wheel speed sensor 22 determines that the vehicle 100 is stuck, it is desirable to stop the ACC after a predetermined time has elapsed since the detection of the stuck state. It is also desirable for the ACC unit 15 to encourage the driver to take action by providing a notification and to transfer control to the driver's accelerator operation. This is because if the vehicle cannot be freed from being stuck even with the gradual increase in engine torque by the ACC, it is desirable to attempt to free the vehicle from being stuck under the driver's control. By having the driver take action, the vehicle can perform the escape operation with higher engine torque and actively control the brakes. Moreover, by entrusting this operation to the driver, the driver can perform the operation to escape from rough terrain without fear.

[0039] [Sport Mode (4th Mode)] Sport mode, for example, makes driving on winding roads such as mountain roads more comfortable by switching to 4WD more frequently, requiring frequent steering input. It also maintains a higher engine RPM, making it suitable for merging and overtaking on highways. Sport mode allows for a certain degree of slippage, increasing the driver's freedom in controlling the vehicle's behavior and facilitating strong acceleration. Therefore, ACC and TCS conditions are set to allow for driving that reflects these driver preferences, even when ACC driving assistance is active.

[0040] In Sport mode, the intervention thresholds under TCS conditions are set higher than in Normal mode for both engine torque reduction and brake control. By setting a higher intervention threshold for traction control, it becomes more difficult for the brakes to intervene, allowing for some slippage due to the increased acceleration of ACC. Furthermore, setting a higher intervention threshold under TCS conditions also helps to suppress the reduction of engine torque caused by TCS operation. Additionally, by making it more difficult for the TCS to intervene with brake control, it is possible to improve starting performance while reducing noise, vibration, and power consumption.

[0041] Furthermore, under ACC conditions, at least one of the engine torque magnitude and increase rate is set to a higher value than in normal mode. This setting helps prevent drivers seeking acceleration from inadvertently pressing the accelerator pedal and interrupting ACC. As a result, as shown by the thin dashed line in the graph of Figure 4, high acceleration can be maintained even when ACC is activated in sport mode. In other words, even in ACC mode, the driver can be given the acceleration feeling characteristic of sport mode.

[0042] Next, the methods of activating and temporarily disabling ACC by the ACC unit 15 will be explained using the flowchart in Figure 5.

[0043] First, if the ACC start switch 23 is not turned ON, the ACC unit 15 will not start (if NO in step S11, proceed to END after step S12). When the ACC start switch 23 is turned ON (YES in step S11), the ACC enters standby mode. Then, if the driver presses the brake pedal (hereinafter referred to as "driver braking") (NO in step S13), the activation of the ACC is temporarily disabled (step S14). As long as the temporary disable state of the ACC is not released (NO in step S15), the ACC will not activate (END). In other words, as long as the temporary disable state of the ACC is not released, the driving speed of the vehicle 100 is controlled solely by the driver's driving.

[0044] On the other hand, when the temporary disable state of ACC is released (YES in step S15), activation of ACC is permitted (step S17). Once activation of ACC is permitted (step S17), when vehicle 100 reaches a predetermined driving speed, driving control by ACC is started. Furthermore, if the driver brake is not applied (YES in step S13), the ACC unit 15 checks whether the driver has pressed the accelerator pedal (hereinafter referred to as "driver accelerator") (step S16).

[0045] If the accelerator pedal is depressed (NO in step S16), ACC activation is temporarily prohibited, and driving continues using the driver's accelerator (step S18). As long as the driver's accelerator pedal is depressed, the driver continues to control the driving speed (NO in step S19). When the accelerator pedal is released (YES in step S19), ACC activation is permitted (END after step S17).

[0046] Here, if the selected driving mode is anything other than lock mode (YES in step S20), permission to activate ACC is retained (END after step S17). In other words, when the vehicle 100's driving speed exceeds a predetermined speed, driving control by ACC is initiated.

[0047] On the other hand, if a vehicle gets stuck while the selected driving mode is in lock mode (NO in step S20 and YES in step S21), the engine torque is set to a high value (step S22). Then, until a predetermined time has elapsed with the engine torque set to high (NO in step S23), ACC control in lock mode is performed (END after step S26). At this time, the amount of control by ACC is performed at the initial value specified in the ACC control conditions for lock mode. If a predetermined time has elapsed with the engine torque set to high (YES in step S23), the ACC will continue to be activated until the stuck time has elapsed for a predetermined amount of time (NO in step S24) (END).

[0048] On the other hand, if the engine torque remains high for a predetermined time, and the stuck time also exceeds a predetermined time (YES in step S23 and YES in step S24), the ACC is temporarily disabled, and the driver is notified that the ACC has been temporarily disabled by displaying it on the instrument panel or elsewhere (END after step S25).

[0049] Furthermore, if no stacking occurs (NO in step S21), the ACC control amount is executed with the initial value specified by the ACC condition in lock mode (END after step S26).

[0050] As described above, the driver assistance system 10 and vehicle 100 according to this embodiment can be used not only on highways with stable road conditions, but also on general roads such as snowy or muddy roads, and the ACC function can be used according to the road conditions and the driver's preferences. Therefore, the range of ways in which the driver can use ACC is broadened. Furthermore, control with autonomous driving in mind becomes possible.

[0051] While several embodiments of the present invention have been described, these embodiments are presented as examples only and are not intended to limit the scope of the invention. These embodiments can be carried out in a variety of other forms, and various omissions, substitutions, modifications, and combinations are possible without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims and their equivalents.

[0052] For example, the available driving modes vary depending on the vehicle model. Some models, for instance, have an eco mode that prioritizes fuel efficiency. [Explanation of symbols]

[0053] 10...Driving assistance system, 11...Driving mode determination unit, 12...Traction control unit (TC unit), 13...Brake ECU, 14...Follow driving activation command unit (ACC activation command unit), 15...Follow control unit (ACC unit), 16...Engine ECU, 17...Memory unit, 21...Driving mode selection switch, 22...Wheel speed sensor, 23...Follow control start switch (ACC start switch), 24 (24a, 24b)...Preceding vehicle detection unit (camera, millimeter wave radar), 25...Engine, 26...Brake system, 30...Instrument panel, 31...Console box, 32...Shift lever, 33...Console upper panel, 34...Meter panel, 35...Navigation panel, 37 (37a)...Steering wheel (pillar part), 100...Vehicle.

Claims

1. A driving mode determination unit that determines the driving mode according to the driving mode selected by the vehicle driver, A traction control unit controls at least one of the engine and the brake system to suppress the slip of the drive wheels when the amount of slip of the drive wheels exceeds an intervention threshold, in accordance with the traction control conditions defined for each of the aforementioned driving modes. The system includes a follow-up driving control unit that controls follow-up driving that follows a preceding vehicle according to follow-up control conditions defined for each of the aforementioned driving modes, The follow-up driving control unit is characterized in that, when the driving mode is switched, it controls the follow-up driving by changing the follow-up control conditions to those defined in the driving mode after the switch. The aforementioned driving mode is, A first mode in which at least one of the intervention threshold and traction control amount defined in the traction control conditions and at least one of the engine torque and brake force defined in the follow-up control conditions are all at their default values, A selection mode having different traction control conditions than the first mode, The selection mode includes a second mode in which the intervention threshold for the brake force of the traction control condition is defined to be smaller than that of the first mode. In the tracking control conditions of the second mode, The amount of engine torque controlled at the time of starting is set lower than that of the first mode. A driving assistance device in which the rate of increase of the engine torque when the vehicle speed exceeds a predetermined speed is set to be greater than that of the first mode.

2. In the tracking control conditions in the second mode, The distance between the vehicle and the preceding vehicle is set to be greater than in the first mode. The driving assistance device according to claim 1, wherein the operating timing of the brake system of the vehicle is set earlier than that of the first mode.

3. A driving mode determination unit that determines the driving mode according to the driving mode selected by the vehicle driver, A traction control unit controls at least one of the engine and the brake system to suppress the slip of the drive wheels when the amount of slip of the drive wheels exceeds an intervention threshold, in accordance with the traction control conditions defined for each of the aforementioned driving modes. The system includes a follow-up driving control unit that controls follow-up driving that follows a preceding vehicle according to follow-up control conditions defined for each of the aforementioned driving modes, The follow-up driving control unit is characterized in that, when the driving mode is switched, it controls the follow-up driving by changing the follow-up control conditions to those defined in the driving mode after the switch. The aforementioned driving mode is, A first mode in which at least one of the intervention threshold and traction control amount defined in the traction control conditions and at least one of the engine torque and brake force defined in the follow-up control conditions are all at their default values, A selection mode having different traction control conditions than the first mode, The selected mode includes a third mode in which, in a vehicle speed range below a predetermined vehicle speed, the torque reduction of the engine by the traction control unit is suppressed or prohibited, and the brake force of the traction control condition is set to be greater than that of the first mode. A driver assistance device in which, in the follow-up control conditions of the third mode, the engine torque at the time of starting is set to be greater than that of the first mode.

4. The driver assistance device according to claim 3, wherein if a stuck vehicle is detected during the follow control in the third mode, the engine torque is increased in stages, and when a predetermined time has elapsed after the detection of the stuck vehicle, the follow control is stopped and the driver's operation is notified.

5. In the third mode's follow-up control conditions, the engine torque at startup is further set to be greater than in the first mode. The selection mode further includes a fourth mode in which the intervention threshold of the traction control unit is set to be greater than that of the first mode. The driving assistance device according to claim 3, wherein the magnitude of the engine torque during the follow-up control at the time of starting in the follow-up control conditions is smaller in the third mode than in the fourth mode.

6. A driving mode selector switch that is operated by the vehicle driver to switch the driving mode, A wheel sensor that monitors the rotation status of the wheel, A traction control unit controls at least one of the engine and the brake system to suppress the slip of the drive wheels when the amount of slip of the drive wheels exceeds an intervention threshold, in accordance with the traction control conditions defined for each of the aforementioned driving modes. A preceding vehicle detection unit that detects a preceding vehicle traveling in front of the aforementioned vehicle, A follow-up driving start switch operated by the aforementioned driver, A follow-up driving start command unit triggers the operation of the follow-up driving start switch and issues a command to start follow-up driving in accordance with the follow-up control conditions defined for each driving mode, which follows the preceding vehicle. A vehicle characterized by comprising: a follow-up driving control unit that controls the follow-up driving by changing the follow-up control conditions to those defined in the driving mode after the switch when the driving mode is switched after the activation command.

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