JP2004090788A - Vehicular travel control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicular travel control device capable of observing the speed limit of each road without burdening a driver. <P>SOLUTION: The travel control device comprises a travel control section (2h) performing a low-speed follow-up traveling which follows a preceding vehicle while limiting a vehicle speed of an own vehicle to the maximum control vehicle speed or less, a speed-limit discriminating section (2f) discriminating a speed limit of a road on which the vehicle travels at present, and a maximum control vehicle speed setting section (2g) setting the maximum control vehicle speed under the low-speed follow-up traveling according to the speed limit. The travel control device performs the low-speed follow-up traveling without exceeding the maximum control vehicle speed which is the speed limit of each road or less. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a travel control device for a vehicle that performs low-speed tracking while restricting the vehicle speed of the own vehicle to a maximum control vehicle speed or less in a low vehicle speed range, and particularly to a speed control without burdening a driver during low-speed tracking. The present invention relates to a travel control device that enables compliance.
[0002]
[Related background art]
In recent years, a travel control device provided with a tracking function to reduce a driver's operational burden has been put to practical use. For example, as described in Japanese Patent Application Laid-Open No. H11-78605, such a traveling control device controls an engine output and a braking force based on inter-vehicle distance information detected by an inter-vehicle distance sensor when a preceding vehicle exists. There is known an adaptive cruise control (ACC) device that keeps a distance between the vehicle and a preceding vehicle constant, and runs the vehicle at a constant speed at a set speed when there is no preceding vehicle.
[0003]
Tracking control by the ACC device is useful for reducing the burden on the driver when the vehicle is traveling in the middle vehicle speed range. However, if the inter-vehicle distance is kept constant during traveling in a city area, especially when traveling on a congested road, changes in the vehicle speed of the preceding vehicle may occur. Accordingly, the vehicle speed of the own vehicle may frequently change, thereby impairing smooth running.
Therefore, for example, as described in Japanese Patent Application Laid-Open No. 2001-10373, an enhanced adaptive cruise control (hereinafter, referred to as “enhanced adaptive cruise control”) that sets a maximum control vehicle speed in tracking control and limits the vehicle speed of the own vehicle during tracking travel to the maximum control vehicle speed. EACC) devices have been proposed. In this proposed device, the maximum control vehicle speed in EACC is set to an appropriate value such as about 40 to 60 km / h in advance.
[0004]
[Problems to be solved by the invention]
In urban areas, the speed limit is finely defined for each road according to the road environment. Even if the vehicle speed is limited to the maximum control vehicle speed by the EACC, if the maximum control vehicle speed is set to a constant value, the traveling route Depending on the speed limit, it may not be possible to comply with the speed limit. Therefore, a configuration in which the driver changes the maximum control vehicle speed in accordance with the speed limit for each road can be considered, but such a configuration imposes a burden on the driver and impairs the practicality of the EACC device. Further, if the maximum control vehicle speed is set to a small value, the own vehicle will travel at a low speed even when traveling on a road with a relatively high speed limit, which may obstruct the flow of the vehicle.
[0005]
SUMMARY OF THE INVENTION It is an object of the present invention to provide a traveling control device for a vehicle that can comply with a speed limit for each road without imposing a burden on a driver.
[0006]
[Means for Solving the Problems]
The traveling control device according to the present invention includes a tracking control unit that performs low-speed tracking traveling to track a preceding vehicle while restricting a vehicle speed of the own vehicle to a maximum control vehicle speed or less in a low vehicle speed range, and a restriction on a road on which the vehicle is currently traveling. It is characterized by comprising: speed limit determining means for determining a speed; and maximum control vehicle speed setting means for setting a maximum control vehicle speed in low-speed tracking travel to a speed equal to or lower than the determined speed limit.
[0007]
According to the present invention, the vehicle speed of the host vehicle is controlled to be equal to or lower than the maximum control vehicle speed during low-speed tracking travel. This maximum control vehicle speed is set to a speed equal to or less than the speed limit on the currently traveling road determined by the speed limit determining means, and therefore, during low-speed tracking travel, the vehicle speed of the own vehicle is limited to the speed limit or less. The speed limit will be ensured. Moreover, the setting of the maximum control vehicle speed is performed by the maximum control vehicle speed setting means, so that no burden is imposed on the driver.
[0008]
In the present invention, preferably, the travel control device notifies that the setting of the maximum control vehicle speed has been changed according to a setting change signal transmitted from the maximum control vehicle speed setting means when the setting of the maximum control vehicle speed has been changed. A notification unit is provided.
According to this preferred aspect, the driver is notified by the notification means that the setting of the maximum control vehicle speed has been changed. For example, the vehicle speed of the host vehicle has decreased due to entering a low speed limit road from a high speed limit road. In this case, the driver is less likely to inadvertently release the low-speed tracking travel function of the travel control device.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a vehicle travel control device according to an embodiment of the present invention will be described with reference to the drawings.
The traveling control device according to the present embodiment is preferably configured as an EACC (Enhanced Adaptive Cruise Control) device, and performs tracking traveling to maintain the inter-vehicle distance with the preceding vehicle when the preceding vehicle exists, If it does not exist, the vehicle will be driven at a constant speed at the set speed, and in low speed tracking traveling in the low speed range, the vehicle speed of the vehicle will be limited to the maximum control vehicle speed, the inter-vehicle distance with the preceding vehicle will be constant, and The start and stop of the own vehicle are controlled accordingly.
[0010]
As shown in FIG. 1, the traveling control device includes an electronic control unit (ECU) 2 having an input processing unit 4, a control state calculation unit 6, a control content calculation unit 8, and a display content calculation unit 10.
On the input side of the ECU 2, a control power switch 11, an inter-vehicle distance measuring device 12, a traveling lane recognition device 13, a speedometer 14, an operation switch 15, a GPS receiving antenna 16 for receiving radio waves from GPS satellites, a speed limit for each road A CD-ROM 17 storing road map information including information and various sensor switches 20 are connected. The various sensor switches 20 include a throttle sensor, a wheel speed sensor, a steering angle sensor, a warning switch (indicated by reference numeral 54 in FIG. 2), and the like.
[0011]
Here, the inter-vehicle distance measuring device 12 includes a CCD camera and a scanning laser radar (indicated by reference numerals 12a and 12b in FIG. 5) provided at a front portion of the vehicle. It measures the distance between the vehicle and the vehicle. The traveling lane recognition device 13 is mainly composed of a CCD camera, and is used for confirming the traveling lane. The operation switch 15 is of a lever type and is provided, for example, on a steering wheel 56 (FIG. 2). By raising the operation switch 15, an operation of increasing the set vehicle speed Vm and an operation of decreasing the inter-vehicle time TC, which will be described later, are performed, and by lowering the operation, the input of a travel control start command, the operation of decreasing the set vehicle speed Vm, and the inter-vehicle time TC are performed. The operation for increasing the vehicle speed and the operation for returning to the set vehicle speed Vm (resume operation) are performed, and the operation control release command is input to the ECU 2 by operating the operation switch 15 to the front.
[0012]
On the other hand, on the output side of the ECU 2, a throttle actuator 30, an automatic transmission (A / T) 32, a brake actuator 34, and a display 40 for displaying a running control state are connected.
As shown in FIG. 2, the instrument panel 50 in the driver's seat includes a control power switch 11, a warning switch 54 for activating an inter-vehicle distance warning buzzer (not shown) for notifying the approach of a preceding vehicle by a warning sound, and a display. A combination meter 60 as 40 and a center message display 41 are provided.
[0013]
The combination meter 60 has a travel control operation display lamp 62 indicating whether the travel control is being performed, a warning buzzer operation lamp 64 indicating whether the following distance warning buzzer is operating, and the maximum control vehicle speed has been changed. And a change display lamp 66 for notifying the user.
The center message display 41 includes a set vehicle speed display section 42 for displaying the set vehicle speed Vm in a line drawing indicating the own vehicle, an inter-vehicle distance display section 44 for displaying an inter-vehicle distance DS between two arrows, A preceding vehicle display section 46 for displaying the presence or absence of a preceding vehicle with a line drawing indicating the rear of the car, and a warning lamp 48 are provided.
[0014]
In the travel control device having the above configuration, the travel control routine of FIG.
The running control routine includes a step S10 for initializing the controller in response to the turning on of the system power by the control power switch 11 after the ignition is turned on, and a main routine after the step S12. The main routine is executed at a constant control cycle ts. It is repeatedly performed.
[0015]
In step S12, the timer for measuring the control cycle ts is reset.
In the next step S14, signal processing of various input signals supplied from the following distance measuring device 12, the traveling lane recognition device 13, the vehicle speedometer 14, the operation switch 15, the GPS receiving antenna 16, the CD-ROM 17, and the various sensor switches 20 Is performed. Specifically, reading of a signal from the operation switch 15, calculation of the vehicle speed VS, throttle opening, wheel speed and steering angle, acquisition of image controller data from the CCD camera, and the like are performed. Further, the current vehicle position is detected based on the output from the GPS receiving antenna 16, and based on the current vehicle position and the road map information including the speed limit information from the CD-ROM 17, the road on which the vehicle is currently traveling is determined. Is determined, and the speed limit Vr on the road is determined, and the speed limit Vr is stored in the memory of the ECU 2.
[0016]
In the next step S16, data of the preceding vehicle is calculated based on the signal from the scanning laser radar. Specifically, it is determined whether or not there is a candidate vehicle in the traveling lane, selection of a preceding vehicle when there is a candidate vehicle in the traveling lane, and the current inter-vehicle distance DS and relative speed Vba between the preceding vehicle and the own vehicle. An operation or the like is performed.
In step S18, it is determined whether or not the image signal from the CCD camera is turbulent or the laser radar is dirty, and if there is turbulence or dirt, a failure process is performed.
[0017]
In step S20, various control data setting processes are performed based on the input signal processing results and the preceding vehicle data calculation results in steps S14 and S16.
Here, first, the inter-vehicle time TC input by the operation of the operation switch 15 by the driver is set to an appropriate value (for example, 1.5 sec to 2.5 sec) according to the operation amount of the operation switch 15 from a map (not shown). Is done.
[0018]
Then, the set inter-vehicle distance Dset is calculated based on the inter-vehicle time TC, and the safe inter-vehicle distances DSF1 and DSF2 are calculated. The set inter-vehicle distance Dset is used to determine whether or not the preceding vehicle is within a range in which the tracking control is to be performed, and is used as a target inter-vehicle distance during tracking of the preceding vehicle. Further, the safe inter-vehicle distances DSF1 and DSF2 are threshold values for securing a sufficient inter-vehicle distance, and are obtained from a map (not shown) according to the vehicle speed.
[0019]
Further, a maximum control vehicle speed Vmax, which is a threshold value for determining a shift from the low speed tracking control mode to the maximum vehicle speed control mode, is set. In this maximum control vehicle speed setting, the currently set maximum control vehicle speed Vmax and the speed limit Vr on the currently traveling road are read from a memory (not shown) of the ECU 2. Here, the speed limit Vr is determined in step S14 of FIG. 3 based on the current vehicle position detected from the output of the GPS receiving antenna 16 and the map information from the CD-ROM 17, and stored in the memory. . On the other hand, the current maximum control vehicle speed Vmax is, for example, the set vehicle speed Vm in the tracking control mode prior to the previous maximum control vehicle speed setting or the speed limit Vr on the road on which the vehicle was traveling at that time.
[0020]
Next, it is determined whether or not the current maximum control vehicle speed Vmax exceeds the speed limit Vr on the road on which the vehicle is currently traveling. If the current maximum control vehicle speed Vmax is equal to or lower than the speed limit Vr, the maximum control vehicle speed Vmax is maintained. Is done. On the other hand, if the current maximum control vehicle speed Vmax is higher than the limit speed Vr, the limit speed Vr is set as a new maximum control vehicle speed Vmax, whereby the setting of the maximum control vehicle speed Vmax is changed. In this case, in step S28 to be described later, the change display lamp 66 of the combination meter 60 is driven by the display content calculation unit 10 and blinks, for example, to notify the driver of the setting change of the maximum control vehicle speed Vmax.
[0021]
Steps S14 to S20 are performed by the input processing unit 4 in FIG.
In the next step S22, based on the set inter-vehicle distance Dset, the safe inter-vehicle distances DSF1 and DSF2, the current inter-vehicle distance DS, the driver's switch operation, and the like, the control mode transition processing (selection of the control mode) is performed by the control state calculation unit 6. Will be implemented by
Hereinafter, with reference to FIG. 4, each control mode, the transition between the control modes, and the processing performed in steps S24 and S26 will be described.
[0022]
As shown in FIG. 4, immediately after the power is turned on, an initialization mode M10 for executing the initialization in step S10 in FIG. 3 is performed, and when this initialization process is completed, the process proceeds to a control OFF mode M12. In the control OFF mode M12, the traveling control is not performed, and the driver performs a normal driving operation.
When the traveling control is started in response to the operation of the operation switch 15, the control mode to be shifted is determined based on the execution results in steps S14, S16, and S20 in FIG.
[0023]
If the vehicle speed VS is in the middle and high speed range (for example, 40 km / h ≦ VS ≦ 105 km / h) and the current inter-vehicle distance DS is larger than the set inter-vehicle distance Dset, the process transits to the constant speed control mode M14 and sets the current vehicle speed VS. The vehicle speed Vm is stored in the ECU 2 and the traveling control is performed so as to maintain the set vehicle speed Vm. When the operation switch 15 is operated in the constant speed control mode M14, the mode shifts to a speed adjustment mode M16 for increasing or decreasing the set vehicle speed Vm.
[0024]
On the other hand, if the vehicle speed Vs is in the middle to high speed range and the current inter-vehicle distance DS is equal to or less than the set inter-vehicle distance Dset, it is determined that a preceding vehicle is present ahead of the own vehicle, and the mode transits to the tracking control mode M18. The set vehicle speed Vm that is larger than the vehicle speed VS by α (for example, 10 km / h) is stored in the ECU 2, and tracking control is performed so that the inter-vehicle distance to the preceding vehicle is kept constant. However, it does not exceed the set vehicle speed Vm. When the operation switch 15 is operated in the tracking control mode M18, the mode shifts to the inter-vehicle adjustment mode M20 in which the set inter-vehicle distance Dset can be increased or decreased.
[0025]
If the vehicle speed Vs at the start of the traveling control is in a low-speed range (for example, less than 40 km / h) and the inter-vehicle distance Ds is equal to or less than the set inter-vehicle distance Dset, the mode transits to the low-speed tracking control mode M28, and the inter-vehicle distance with the preceding vehicle becomes the inter-vehicle distance. The low-speed tracking control is performed such that the inter-vehicle distance Dset determined according to the time Tc is achieved. That is, traveling control is performed with the set inter-vehicle distance Dset as the target inter-vehicle distance, and the throttle actuator 30, the A / T 32, and the brake actuator 34 are controlled in accordance with the increase or decrease of the vehicle speed of the preceding vehicle, and the vehicle speed of the own vehicle is controlled to increase or decrease. You. When the preceding vehicle stops, the vehicle speed of the own vehicle is reduced to zero in order to maintain the set inter-vehicle distance Dset, and the vehicle stops. Thereafter, when the preceding vehicle starts and the inter-vehicle distance exceeds the set inter-vehicle distance Dset, the own vehicle starts to maintain the set inter-vehicle distance. In the low-speed tracking control mode M28, the set inter-vehicle distance Dset can be increased or decreased by operating the operation switch 15.
[0026]
As described above, in this embodiment, when the operation switch 15 is operated in the control OFF mode M12, the traveling control in the low-speed control mode M14, the tracking control mode M18, or the low-speed tracking control mode M28 is started. The control mode changes according to the change in the vehicle running state.
For example, if the inter-vehicle distance DS with the preceding vehicle becomes less than or equal to the set inter-vehicle distance Dset during the traveling control in the constant speed control mode M14, the control proceeds to the tracking control mode M18. In the constant speed control mode M14 and the tracking control mode M18, when the inter-vehicle distance DS becomes smaller than the safe inter-vehicle distance DSF1 corresponding to the vehicle speed VS, the mode transits to the slow deceleration control mode M22, and the throttle actuator 30 is drive-controlled to the closing side. The vehicle speed VS is reduced by the action of the engine brake. Nevertheless, if the inter-vehicle distance VS becomes smaller than the safe inter-vehicle distance DSF2, the mode transits to the deceleration control mode M24, in which the A / T 32 is downshifted or the brake actuator 34 is drive-controlled to further reduce the vehicle speed VS. When the inter-vehicle distance DS exceeds the safe inter-vehicle distance DSF2, the process returns to the slow deceleration control mode M22. Thereafter, when the inter-vehicle distance DS exceeds the safe inter-vehicle distance DSF1, the process returns to the tracking control mode M18.
[0027]
If the vehicle speed Vs of the own vehicle increases with the acceleration of the preceding vehicle during the traveling control in the low-speed tracking control mode M28 and becomes equal to or higher than the maximum control vehicle speed Vmax, the mode shifts from the low-speed tracking control mode to the maximum vehicle speed control mode M30. , The vehicle speed Vs is maintained at the maximum control vehicle speed Vmax. That is, in the low-speed tracking control mode M28, the ECU 2 functions as a tracking control unit that performs low-speed tracking traveling to track the preceding vehicle while limiting the vehicle speed to the maximum control vehicle speed Vmax or less.
[0028]
During the traveling control in the tracking control mode M18, the slow deceleration control mode M22, the deceleration control mode M24, or the maximum vehicle speed control mode M30, when the preceding vehicle stops suddenly and the inter-vehicle distance DS becomes infinite, the vehicle shifts to the vehicle speed holding mode M26. The holding vehicle speed Vh, which is the vehicle speed VS at the time of the lost target, is held for a predetermined time t2 (for example, 3 sec), and after the predetermined time t2 elapses, the process returns to the constant speed control mode M14.
[0029]
In step S28 of FIG. 3, various display and warning output processing are performed by the display content calculation unit 10, and the drive control operation display lamp 62, the warning buzzer operation lamp 64, and the center message display 41 shown in FIG. Further, when the inter-vehicle distance DS becomes smaller than the inter-vehicle distance for which the alarm is activated, the inter-vehicle distance warning buzzer (not shown) is driven based on the inter-vehicle distance alarm processing of the input processing unit 4 to emit a warning sound. As described above, the maximum control vehicle speed Vmax, which is a threshold value for determining whether to shift from the low-speed tracking control mode to the maximum vehicle speed control mode, is set in the process of setting various control data in step S20 in FIG. At this time, when the setting of the maximum control vehicle speed Vmax is changed to the speed limit Vr, the change display lamp 60 of the combination meter 60 is driven by the display content calculation unit 10 to blink, and it is notified that the setting of the maximum control vehicle speed Vmax has been changed. Notify the driver.
[0030]
The traveling control device of the present embodiment controls the start and stop of the own vehicle as needed in the low-speed tracking control mode M28 while maintaining a constant inter-vehicle distance with the preceding vehicle, and the own vehicle speed is controlled to the maximum control vehicle speed Vmax. When the vehicle speed reaches the maximum control vehicle speed control mode M30, the vehicle speed of the own vehicle is maintained at the maximum control vehicle speed Vmax, and the maximum control vehicle speed Vmax is the speed limit of the road on which the vehicle is currently traveling. It is characterized in that the maximum control vehicle speed is set so as to be equal to or lower than Vr, and the driver is notified when the setting of the maximum control vehicle speed is changed.
[0031]
FIG. 5 is a schematic block diagram illustrating functions of the ECU 2 related to the above-described features.
Each of the various functional units of the ECU 2 shown in FIG. 5 has the functions of the corresponding parts of the input processing unit 4, the control state calculating unit 8 and the display content calculating unit 10 of FIG. Execute the corresponding processing of the routine.
In brief, the ECU 2 receives a preceding vehicle determination unit 2a that determines the presence or absence of a preceding vehicle based on a detection output of the CCD camera 12a, an inter-vehicle time input by operating the operation switch 15 by the driver, and an input from the vehicle speedometer 14. The target inter-vehicle distance calculating unit 2b that calculates the target inter-vehicle distance based on the vehicle speed to be performed, and the relative speed between the preceding vehicle and the own vehicle from the time change of the actual inter-vehicle distance based on the actual inter-vehicle distance input from the laser radar 12b. A relative speed calculator 2c to be determined, a preceding vehicle speed calculator 2d to determine the vehicle speed of the preceding vehicle based on the relative speed and the vehicle speed of the own vehicle input from the vehicle speedometer 14, and outputs from these functional units 2a to 2d. And a travel control unit 2 that drives and controls the throttle actuator 30, the A / T 32, and the brake actuator 34 based on
[0032]
Further, the ECU 2 determines the current position of the vehicle based on the position information input from the GPS satellites via the GPS receiving antenna 16, the vehicle current position determination unit 2 e, and the current position of the vehicle and the restriction input from the CD-ROM 17. The speed limit judging section (speed limit judging means) 2f for obtaining the speed limit Vr of the road on which the vehicle is currently traveling based on the map information including the speed information and the driver's operation of the operation switch 15 are input. A maximum control vehicle speed setting unit (maximum control vehicle speed setting means) 2g that sets the smaller of the set vehicle speed Vm and the limit speed Vr as the maximum control vehicle speed Vmax, and a setting unit 2g that sends when the maximum control vehicle speed Vmax is changed. And a display driving unit 2i for causing a change display lamp 66 (FIG. 2) of the display 40 to blink, for example, in response to the setting change signal.
[0033]
Regarding the setting of the maximum control vehicle speed Vmax, the ECU 2 executes a maximum control vehicle speed setting routine shown in FIG. 6 at a predetermined cycle. In this setting routine, the current position of the own vehicle is determined based on the position information input from the GPS satellite (step S61), and the current position of the own vehicle is determined based on the map information input from the CD-ROM 17 and the current position of the own vehicle. The speed limit Vr is determined (step S62), and it is further determined whether or not the currently set maximum control vehicle speed Vmax exceeds the speed limit Vr (step S63). If the current maximum control vehicle speed Vmax is equal to or lower than the limit speed Vr, the current maximum control vehicle speed Vmax is maintained. On the other hand, if the current maximum control vehicle speed Vmax exceeds the limit speed Vr, the limit speed Vr is set to the new maximum speed. The control vehicle speed Vmax is set (step S64), and a setting change signal is issued to notify the change of the maximum control vehicle speed Vmax (step S65).
[0034]
According to the traveling control device of the present embodiment, when the vehicle speed of the own vehicle exceeds the maximum control vehicle speed Vmax during traveling in the low-speed tracking control mode M28, the vehicle shifts to the maximum vehicle speed control mode M30 to perform the maximum control below the speed limit Vr. Since the vehicle speed is maintained at the vehicle speed Vmax, the driver can comply with the speed limit Vr of the road on which the vehicle is currently traveling without performing any special operation, and the burden on the driver particularly when traveling on a congested road is reduced. Further, since the change of the maximum control vehicle speed Vmax is notified, the possibility that the driver unintentionally releases the low-speed tracking traveling function of the traveling control device is reduced.
[0035]
The present invention is not limited to the above embodiment, and can be variously modified.
For example, in the above embodiment, the speed limit on the currently running road is determined from the position information input from the GPS satellite and the road map information stored in the CD-ROM and including the speed limit. The speed limit can be determined using road-vehicle communication represented by VICS or the like in which various information transmitted from the beacon provided in the vehicle is received by the in-vehicle receiver.
[0036]
It is not essential to provide the control mode shown in FIG. 4 and perform the transition between the control modes shown in FIG. 4, for example, by omitting the speed adjustment mode M16 and the headway adjustment mode M20 shown in FIG. Is also good.
In addition, it is not essential to use a display lamp for notification of the setting change of the maximum control vehicle speed, and other notification means such as a buzzer can be used.
[0037]
【The invention's effect】
The traveling control device according to the present invention includes a tracking control unit that performs low-speed tracking traveling to track a preceding vehicle while restricting a vehicle speed of the own vehicle to a maximum control vehicle speed or less in a low vehicle speed range, and a restriction on a road on which the vehicle is currently traveling. Speed limiting means for determining the speed, and maximum control vehicle speed setting means for setting the maximum control vehicle speed in low-speed tracking travel to a speed equal to or less than the determined speed limit. Is limited to below the speed limit, and the driver can reliably comply with the speed limit for each road without performing any special operation, which is particularly convenient for traveling on congested roads.
[Brief description of the drawings]
FIG. 1 is a schematic diagram of a travel control device according to an embodiment of the present invention.
FIG. 2 is a view showing an indicator provided around an instrument panel of a vehicle equipped with the traveling control device of FIG. 1;
FIG. 3 is a flowchart of a travel control routine executed by an electronic control unit of the travel control device of FIG. 1;
FIG. 4 is a diagram showing transition between a travel control mode selected by an electronic control unit and a control mode.
FIG. 5 is a functional block diagram of an electronic control unit of the traveling control device of FIG.
FIG. 6 is a flowchart of a maximum control vehicle speed setting routine executed by the electronic control unit shown in FIG. 5;
[Explanation of symbols]
2 Electronic control unit (ECU)
2e Vehicle current position determination unit 2f Speed limit determination unit 2g Maximum control vehicle speed setting unit 2h Travel control unit 15 Operation switch 16 GPS reception antenna 17 CD-ROM
30 Throttle actuator 34 Brake actuator 40 Indicator 66 Change display lamp

Claims (1)

Tracking control means for performing low-speed tracking traveling to track a preceding vehicle while limiting the vehicle speed of the own vehicle to a maximum control vehicle speed or less in a low vehicle speed range,
Speed limit determining means for determining a speed limit on a road on which the vehicle is currently traveling;
And a maximum control vehicle speed setting means for setting the maximum control vehicle speed in the low-speed tracking travel to a speed equal to or lower than the determined speed limit.

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