JP2002089314A - Travel control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a travel control device enabling a vehicle to automatically travel at a given speed, and to prevent inappropriate travel of the vehicle. SOLUTION: This travel control device is carried on the vehicle capable of automatic travel, and carries out automatic travel control of the vehicle. The travel control device judges whether or not the vehicle is in an automatic travel mode (S10). When the vehicle is in the automatic travel mode, the travel control device increases an engine speed to a given engine speed larger than that during idling (S18). When the vehicle is traveled at the given engine speed, a braking effort of the vehicle is controlled so that an actual speed of the vehicle is a preset target speed (S30).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a traveling control device for controlling traveling of a vehicle.

[0002]

2. Description of the Related Art Conventionally, as a traveling control device for controlling the traveling of a vehicle, as described in Japanese Patent Application Laid-Open No. 2-70535, a brake depression amount is detected when a slow traveling mode is set. There is known a slow running control device that controls the vehicle speed by changing the throttle opening based on the depression amount. This slow traveling control device is for driving a vehicle at a preset slow vehicle speed, is controlled only by a brake operation, and does not exceed a predetermined vehicle speed. Therefore, the slow traveling control device is suitable for traffic congestion and parking. .

[0003]

However, in this slow running control device, if the throttle opening is operated by the feedback control in order to make the vehicle run at the target vehicle speed, proper running may not be performed. is there. For example,
In order to run at the target vehicle speed, there are problems such as the vehicle getting over the curb in the parking lot. To avoid this,
Coordination with an advanced peripheral monitoring system is required.

Accordingly, the present invention has been made to solve such a problem, and provides a traveling control device capable of preventing an inappropriate traveling of a vehicle while allowing the vehicle to travel at a predetermined speed. The purpose is to do.

[0005]

That is, a travel control device according to the present invention is mounted on a vehicle capable of automatic travel and performs the automatic travel control. Automatic traveling determining means for determining, a rotational speed increasing means for increasing the rotational speed of the engine to a predetermined rotational speed larger than at idling when the automatic traveling determining device determines that the vehicle has entered the automatic traveling mode, And a braking control means for controlling a braking force of the vehicle such that an actual vehicle speed of the vehicle attains a preset target vehicle speed when the vehicle travels at a rotation speed.

Further, the traveling control device according to the present invention releases the automatic traveling mode when the vehicle cannot travel with the driving force at the predetermined rotation speed when the vehicle is to be run at the predetermined rotation speed. Means are provided.

Further, the traveling control device according to the present invention is characterized in that when the automatic traveling mode is released by the above-mentioned releasing means, there is provided a notifying means for notifying the driver of the vehicle of the release information.

According to these inventions, in a state where the engine speed is set to the predetermined speed, the vehicle traveling speed of the vehicle is adjusted by controlling the braking force of the vehicle and automatic traveling is performed. For this reason, it is possible to prevent improper traveling such as when the vehicle forcibly runs over the obstacle when there is an obstacle on the traveling path of the vehicle.

Further, the traveling control device according to the present invention includes vehicle speed detecting means for detecting the actual vehicle speed of the vehicle based on the rotation of a gear rotating in proportion to the actual vehicle speed of the vehicle, and the braking control means is controlled by the vehicle speed detecting means. A deviation between the detected actual vehicle speed and the target vehicle speed is integrated, and the braking force of the vehicle is controlled based on the integration result so that the actual vehicle speed of the vehicle becomes the target vehicle speed. In this case, it is desirable to use forgetting integration as the integration process.

According to the present invention, the deviation between the actual vehicle speed and the target vehicle speed is integrated, and the braking force of the vehicle is controlled based on the integration result. , The hunting of the vehicle can be suppressed as compared with the case where the deviation is proportionally processed.

Further, the traveling control device according to the present invention is characterized in that the traveling control device further comprises a vehicle stopping means for applying a braking force to the vehicle to stop the vehicle before traveling the vehicle at a predetermined rotation speed.

According to the present invention, the vehicle is stopped by applying a braking force before the vehicle is driven, so that the vehicle can be made to follow a predetermined traveling route with high accuracy when the vehicle is automatically driven. In particular, it is useful when employed in an automatic parking device or the like.

Further, the traveling control device according to the present invention is characterized in that the traveling control device is provided with target vehicle speed changing means for changing the target vehicle speed in accordance with the acceleration / deceleration operation of the driver of the vehicle.

[0014] The traveling control device according to the present invention is characterized in that the target vehicle speed changing means lowers the target vehicle speed by operating a brake pedal by a driver.

[0015] The traveling control device according to the present invention is characterized in that the target vehicle speed changing means sets the target vehicle speed to zero when the driver depresses a brake pedal by a predetermined amount or more.

Further, the traveling control device according to the present invention is characterized in that the target vehicle speed changing means increases the target vehicle speed by a driver's accelerator operation.

According to these inventions, the target vehicle speed can be changed by the driver of the vehicle performing the brake operation or the accelerator operation during the automatic traveling. Therefore, automatic traveling can be performed at a vehicle speed that reflects the driver's intention.

Further, the driving control device according to the present invention is characterized in that the automatic driving mode is released when the driver of the vehicle depresses a brake pedal by a predetermined amount or more while the vehicle is in the automatic driving mode. .

According to the present invention, the automatic driving can be forcibly terminated by the driver of the vehicle performing a brake operation of a predetermined amount or more during the automatic driving.

[0020] The traveling control device according to the present invention is characterized in that when the vehicle is in the automatic traveling mode, the vehicle is driven after the driver of the vehicle releases the brake pedal.

According to the present invention, the automatic driving can be started through the brake operation of the driver of the vehicle.

Further, the traveling control device according to the present invention is characterized in that when the braking control means causes the vehicle to travel at a predetermined rotation speed,
The invention is characterized in that the vehicle travels while gradually reducing the braking force of the vehicle.

According to the present invention, the braking force is gradually reduced when the automatic driving starts, so that the vehicle can be prevented from suddenly starting.

Further, the traveling control device according to the present invention applies a braking force to the vehicle through a hydraulic braking mechanism when the vehicle is traveling, and applies a braking force to the vehicle through a mechanical braking mechanism when the traveling of the vehicle is stopped. And

According to the present invention, there is no need to generate hydraulic pressure for applying a braking force when the vehicle stops running. Therefore, energy consumption for applying the braking force can be reduced.

Further, the traveling control device according to the present invention determines whether or not the traveling path of the vehicle is a slope based on the acceleration state of the vehicle when the vehicle is traveling at a predetermined engine speed. Means are provided.

[0027] Further, the traveling control device according to the present invention is characterized in that when the above-mentioned braking control means determines that the traveling path of the vehicle is a hill by the hill determining means, the acceleration component due to the driving force of the vehicle is calculated from the acceleration of the vehicle. The reduced value is added to the control amount as a braking force.

Further, the traveling control device according to the present invention is based on an overshoot of the actual vehicle speed at the time when the vehicle first exceeds the target vehicle speed from the start of traveling when the engine is driven at a predetermined rotation speed. And a slope determining means for determining whether or not the vehicle travels on a slope.

Further, the traveling control device according to the present invention is characterized in that when the braking control means determines that the vehicle travels on a slope by the slope determination means, the braking control means controls the vehicle with a predetermined control amount corresponding to the overshoot. It is characterized by controlling power.

According to these inventions, it is possible to determine whether or not the traveling path on which the vehicle automatically travels is a sloping road, and even if the traveling path is a sloping road, the vehicle can travel properly.

Further, the traveling control device according to the present invention is provided with vehicle speed detecting means for detecting the actual vehicle speed of the vehicle based on the wheel speed and the braking control amount output in a cycle corresponding to the actual vehicle speed of the vehicle. And

According to the present invention, even when the vehicle is traveling at a low speed and the pulse signal cycle corresponding to the actual vehicle speed is long, the calculation of the actual speed is complemented based on the acceleration / deceleration due to the braking, so that the actual vehicle speed is reduced. Detection accuracy can be improved.

Further, the traveling control device according to the present invention includes a road surface state detecting means for detecting a road surface state of a traveling road on which the vehicle automatically travels, and a target vehicle speed changing means for lowering the target vehicle speed when the traveling road is a low μ road. It is characterized by having.

The running control device according to the present invention is characterized in that the antilock control is performed when the slip ratio of the vehicle is larger than a set value.

According to these inventions, slippage during automatic traveling is prevented, and traveling safety is improved.

[0036] Further, the traveling control device according to the present invention is characterized in that output control means for suppressing output of predetermined electric equipment mounted on the vehicle when the vehicle is in the automatic driving mode is provided.

According to the present invention, it is possible to suppress the deterioration of the power balance during automatic traveling.

A traveling control device according to the present invention is a traveling control device for controlling traveling of a vehicle such that the vehicle travels at a slow speed, wherein the traveling mode determines whether or not the vehicle is in a slow traveling mode. It is characterized by comprising a determining means and a driving force maintaining means for maintaining the driving force of the vehicle at a predetermined driving force when the traveling mode determining means determines that the vehicle is in the slow running mode.

According to the present invention, the driving force of the vehicle is maintained at the predetermined driving force when the vehicle is in the slow running mode, so that when the vehicle runs, the running resistance increases due to the condition of the running road. Also, the driving force of the vehicle does not increase. For this reason,
Even when there is an obstacle on the traveling path, inappropriate traveling such as the vehicle traveling over the obstacle by force can be prevented. Further, when the vehicle tries to get on an obstacle on the traveling path, the vehicle speed decreases, so that the driver of the vehicle can detect a traveling abnormality and prevent an inappropriate traveling by a brake operation.

Further, the traveling control device according to the present invention includes a braking control means for performing a braking control of the vehicle so that the actual vehicle speed does not exceed a predetermined set speed when the vehicle is driven with a predetermined driving force. It is characterized by having.

According to the present invention, the braking control is performed so that the actual vehicle speed of the vehicle does not exceed the predetermined speed, thereby preventing the vehicle speed from becoming too high due to the condition of the traveling road such as when the traveling road is downhill. Can be prevented.

Further, in the traveling control device according to the present invention, the above-mentioned braking control means predicts a future actual vehicle speed based on a change in the actual vehicle speed of the vehicle so that the future actual vehicle speed does not exceed a predetermined set speed. The vehicle is further characterized by performing vehicle braking control.

According to the present invention, since the vehicle speed can be reduced in advance, it is possible to prevent a sudden change in the behavior of the vehicle due to the braking control.

[0044]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Various embodiments of the present invention will be described below with reference to the accompanying drawings. In each of the drawings, the same elements are denoted by the same reference numerals, and redundant description will be omitted. Also, the dimensional ratios in the drawings do not always match those described.

(First Embodiment) FIG. 1 shows a configuration diagram of a travel control device according to this embodiment.

As shown in FIG. 1, a traveling control device 1 according to the present embodiment is mounted on a vehicle capable of automatically traveling and performs automatic traveling control, and is applied to an automatic parking device that supports parking of the vehicle. It was done. Here, “automatic traveling is possible” means that the vehicle can travel at a predetermined speed without acceleration / deceleration operation by the driver of the vehicle. The travel control device 1 includes an ECU 2 that is an electronic control device. EC
U2 controls the entire apparatus, and includes a CPU, R
It is composed of an OM, a RAM, an input signal circuit, an output signal circuit, a power supply circuit and the like, and stores various control routines including an automatic traveling control routine.

A wheel speed sensor 3 is connected to the ECU 2. The wheel speed sensor 3 is a sensor that outputs a signal according to the rotation of the wheels of the vehicle, and functions as a vehicle speed detecting unit. The ECU 2 receives the output signal of the wheel speed sensor 3 and calculates the speed of the vehicle, that is, the vehicle speed based on the output signal.

Although only one wheel speed sensor 3 is shown in FIG. 1, a plurality of wheel speed sensors may be provided for each wheel of the vehicle. As the wheel speed sensor 3, for example, an electromagnetic pickup type sensor installed near a gear-shaped rotor that rotates together with the wheels is used. This sensor of the electromagnetic pickup type detects an electromagnetic field change accompanying the movement of the teeth of the gear member.

A brake hydraulic actuator 4 is connected to the ECU 2. Brake hydraulic actuator 4
Is for increasing or decreasing the brake oil pressure applied to the brake 5 based on the control signal of the ECU 2 which is the target oil pressure, and functions as a brake driving means. Further, a stop lamp switch 15 is connected to the ECU 2.

An engine 6 is connected to the ECU 2. The engine 6 is controlled by the ECU 2 that issues an idle-up command.
Is driven at a predetermined rotation speed higher than the rotation speed during idling based on the control signal of

The image processing unit 7 is connected to the ECU 2. Further, a rear camera 8, a left camera 9, a right camera 10, and a display unit 11 are connected to the image processing unit 7, respectively. The rear camera 8 is rear photographing means for photographing the rear of the vehicle. The left side camera 9 is a left side photographing means for photographing the left side of the vehicle. Right camera 10
Is right-side photographing means for photographing the right side of the vehicle. As the rear camera 8, the left camera 9, and the right camera 10, for example, a CCD camera or the like is used.

The image processing section 7 is an image processing device for processing a photographed image based on photographing signals output from the rear camera 8, the left camera 9 and the right camera 10. The display unit 11 is a display unit that displays an image processed by the image processing unit 7 and the like, and displays an image captured by the rear camera 8, the left camera 9, or the right camera 10, and the like.

An automatic travel switch 12 is connected to the ECU 2. The automatic travel switch 12 is a switch for starting automatic travel. This automatic travel switch 1
When the vehicle 2 is turned on, the vehicle is in the automatic traveling mode, and is in a state where automatic traveling is possible.

The ECU 2 has a parking position input unit 13.
Is connected. The parking position input unit 13 is for inputting a parking position. The driver of the vehicle selects and inputs a parking position, a target position for automatic driving is determined by the input, and a calculation of a driving route is performed by the ECU 2. Done. Further, a steering drive unit 14 is connected to the ECU 2.
The steering drive section 14 steers a steered wheel in response to a control signal from the ECU 2.

Next, the operation of the travel control device according to this embodiment will be described.

FIG. 2 is a flowchart showing the operation of the travel control device 1. As shown in S10 of FIG. 2, it is determined whether or not the automatic driving mode has been set. Here, the “automatic traveling mode” means a state in which the vehicle can travel automatically, and the automatic traveling mode enables the vehicle to travel automatically. The automatic traveling mode is started when the automatic traveling switch 12 is turned on. In addition, an operation other than the turning on of the automatic traveling switch 12 may be set as the start condition of the automatic traveling mode.

If it is determined in S10 that the vehicle is not in the automatic traveling mode, the control process ends. on the other hand,
When it is determined in S10 that the vehicle is in the automatic driving mode, the process proceeds to S12, and the target position which is the parking position is determined. The determination of the target position is performed, for example, by the driver of the vehicle operating the parking position input unit 13 while checking the captured image on the display unit 11.

Then, the flow shifts to S14, where a travel route calculation is performed. The travel route calculation is a process of calculating the travel route of the vehicle to the target position. Then, the process proceeds to S16,
Vehicle stop processing is performed. The vehicle stop process is a process in which a drive signal is output from the ECU 2 to the brake hydraulic actuator 4 to increase the brake hydraulic pressure. The vehicle can be reliably stopped by the increase in the brake oil pressure.

Then, the flow shifts to S18, where idle-up processing is performed. The idle-up process is a process of outputting a control signal from the ECU 2 to the engine 6 and increasing the rotation speed of the engine 6 to a rotation speed larger than the rotation speed at the time of idling. Then, the flow shifts to S20, where a traveling start process is performed. The traveling start process is a process for automatically starting traveling of the vehicle under predetermined conditions. Details of the content of the traveling start process will be described later.

Then, the flow shifts to S30, where a braking control process is performed. The braking control process is performed by the engine 6 at a predetermined rotation speed.
Is a process of controlling the braking force of the vehicle such that the actual vehicle speed of the vehicle becomes the preset target vehicle speed while driving the vehicle to give a driving force to the vehicle. For details of the content of the braking control process,
It will be described later.

Then, the flow shifts to S40, where it is determined whether the vehicle can run. This determination process is a process for preventing the vehicle from running improperly by overcoming obstacles on the travel path.It is determined whether the vehicle can travel, for example, whether the actual vehicle speed of the vehicle is not zero. Is determined based on

If it is determined in S40 that the vehicle cannot travel, the flow shifts to S48, where a notification process is performed. The notification process is a process for notifying the driver that the vehicle cannot travel. For example, a predetermined lamp is turned on to notify the driver that the vehicle cannot travel.

On the other hand, when it is determined in S40 that the vehicle can travel, the flow shifts to S44, where it is determined whether the condition for terminating the automatic traveling mode is satisfied. As the end condition of the automatic driving mode, for example, the arrival of the vehicle at the target position is set. In addition, as an end condition of the automatic traveling mode, it is set that the driver depresses the brake pedal by a predetermined amount or more. Thereby, the automatic traveling can be forcibly terminated by the driver's brake operation.

When it is determined in S44 that the condition for terminating the automatic driving mode is not satisfied, the flow returns to S30. On the other hand, when it is determined that the condition for terminating the automatic traveling mode is satisfied, the automatic traveling mode is released, and the automatic traveling control ends.

FIG. 3 shows an example of the traveling start process.

FIG. 4 shows a timing chart of brake hydraulic pressure and braking in automatic traveling control. As shown in FIG. 3, in the traveling start process, the driver of the vehicle releases the brake pedal as a traveling start condition. In S50, it is determined whether the driver of the vehicle is stepping on the brake pedal. Then, when it is determined that the driver of the vehicle is stepping on the brake pedal, S5
Return to 0. On the other hand, when it is determined that the driver of the vehicle has not depressed the brake pedal and released the brake pedal, the process proceeds to S52.

In S52, a control signal is output from the ECU 2 to the brake hydraulic actuator 4, and the brake hydraulic pressure is reduced (time t2 in FIG. 4). When the brake oil pressure is reduced to the constant value p1, the vehicle starts running (time t3 in FIG. 4).

At this time, the brake oil pressure is gradually reduced so as not to be abrupt, as shown by the brake oil pressure change after time t2 in FIG. For example, as a control signal output from the ECU 2 to the brake hydraulic actuator 4, a signal obtained by applying a low-pass filter to a step input is used. After the brake hydraulic pressure is reduced in S52, the traveling start process ends.

FIG. 5 shows an example of the braking control process.

As shown in S60 of FIG. 5, in the braking control process, first, the wheel speed is read. The reading of the wheel speed is performed based on the output signal of the wheel speed sensor 3. Then, the flow shifts to S62, where the actual vehicle speed of the vehicle is calculated based on the wheel speed. Then, the flow shifts to S64, where a deviation between the actual vehicle speed and a preset target vehicle speed is calculated. Here, the target vehicle speed is set to, for example, a speed of 0.25 to 3.0 km.

Then, the flow shifts to S66, where it is determined whether the calculated deviation is larger than a preset value A or not. When it is determined that the deviation is not larger than the set value A, the braking control process ends. On the other hand, when it is determined that the deviation is larger than the set value A, the flow shifts to S68, and the deviation integration processing is performed.

As the integrator used in this integration process, for example, Z / (Z-1) is used. Here, Z is a delay operator. According to the integrator Z / (Z-1), as shown in FIG. 6, a characteristic having a small gain with respect to a high-frequency component is obtained. As an integrator, a forgetting integrator Z / (Z
-A) may be used. However, 0 <a <1. According to the forgetting integrator, as shown in FIG. 7, a characteristic in which the gain of the low frequency component is suppressed to a small value can be obtained. FIG. 8 is a block diagram of a control system in the travel control device 1.

Then, the flow shifts to S70 in FIG. 5, where a control signal based on the integrated deviation is output from the ECU 2 to the brake hydraulic actuator 4, and a braking force is applied to the vehicle by the operation of the brake hydraulic actuator 4. And
The braking control process ends.

As described above, according to the cruise control device 1 of the present embodiment, when the engine 6 is rotated at a predetermined speed higher than the idling speed and a predetermined driving force is applied to the vehicle, the vehicle is controlled. By controlling the braking force, the traveling speed of the vehicle is adjusted and automatic traveling is performed. For this reason, it is possible to prevent improper traveling such as when the vehicle forcibly runs over the obstacle when there is an obstacle on the traveling path of the vehicle.

When the automatic driving mode is released when the vehicle cannot travel with the driving force at the predetermined rotational speed, the driver is notified of the release information to inform the driver of the vehicle that the vehicle is traveling automatically. It can be easily recognized that there is an obstacle or the like.

Further, by integrating the deviation between the actual vehicle speed and the target vehicle speed and controlling the braking force of the vehicle based on the integration result, the vehicle automatically travels at a low speed and the time interval for detecting the vehicle speed becomes longer. Hunting of the vehicle can be suppressed as compared with the case where the deviation is proportionally processed, even when the update cycle of is longer. For example, when the actual vehicle speed detecting means is an electromagnetic pickup type wheel speed sensor 3 that detects the actual vehicle speed based on the rotation of a gear that rotates in proportion to the actual vehicle speed, the vehicle is at a low speed (for example, 0.25 to 3. When the vehicle automatically travels at 0 km / h), the update cycle of the output signal of the wheel speed sensor 3 input to the ECU 2 becomes longer. When the number of gear teeth is about 50, the update cycle is 100 ms or more. If a braking force is applied to the vehicle in such a long cycle, the vehicle may hunt. As a countermeasure, when the deviation between the actual vehicle speed and the target vehicle speed is integrated and the braking force of the vehicle is given based on the integration result, the deviation is proportionally processed and the braking force of the vehicle is given based on the result. In comparison, a sudden change in the braking amount is suppressed. For this reason, hunting of the vehicle can be suppressed.

As shown in FIG. 7, the gain of the low-frequency component is set to 0 as shown in FIG.
Since the value is close to dB, the phase lag in the low frequency component is improved, and the vehicle can travel without giving a feeling of strangeness to the driver.

Further, by applying a braking force to the vehicle and stopping the vehicle before automatically driving the vehicle at a predetermined rotation speed, the vehicle can accurately follow a predetermined traveling route when the vehicle is automatically driven. Can be. In particular, it is useful when employed in an automatic parking device or the like.

When the driver of the vehicle depresses the brake pedal by a predetermined amount or more while the vehicle is in the automatic driving mode, the automatic driving mode is released.
The automatic driving can be forcibly terminated by the driver of the vehicle performing a brake operation of a predetermined amount or more during the automatic driving.

Further, when the vehicle is in the automatic traveling mode, the vehicle is driven after the driver releases the brake pedal, whereby the vehicle can be started automatically through the brake operation of the driver.

When the vehicle is automatically driven at a predetermined engine speed, the vehicle can be prevented from suddenly starting by gradually reducing the braking force of the vehicle and running the vehicle.

(Second Embodiment) Next, a travel control device according to a second embodiment will be described.

The traveling control device according to the present embodiment has the same structure as the traveling control device 1 according to the first embodiment shown in FIG. 1, but a target vehicle speed changing means for changing a target vehicle speed in automatic traveling. It is different in that it has

FIG. 9 is a flowchart showing the operation of the travel control device according to this embodiment.

As shown in FIG. 9, it is determined in S10 whether or not the vehicle is in the automatic traveling mode, a target position is determined in S12, a traveling route calculation is performed in S14, and a vehicle stop process is performed in S16. Is performed, an idle-up process is performed in S18, a traveling start process is performed in S20, and a braking control process is performed in S30. These processes in S10 to S30 are performed in the same manner as described in the first embodiment.

Then, after the braking control processing is completed in S30, the flow shifts to S32, where the target vehicle speed changing processing is performed. The target vehicle speed change process is a process of changing the target vehicle speed according to the driver's will. Details of the target vehicle speed change processing will be described later.

Then, after the target vehicle speed changing process is completed, S4
At 0, it is determined whether or not the vehicle can travel, and if it is determined that the vehicle can travel, it is determined whether or not the end condition of the automatic traveling mode is satisfied (S44). On the other hand, when it is determined in S40 that traveling is not possible, a notification process is performed (S48). These processes in S40, S44, S48 are also performed in the same manner as described in the first embodiment. Then, when the condition for terminating the automatic traveling mode is satisfied in S44 or when the notification process is terminated in S48, the automatic traveling control is terminated.

FIG. 10 shows a flowchart of the target vehicle speed changing process.

As shown in S80 of FIG. 10, it is determined whether or not the stop lamp switch 15 has been turned on.
Here, the ON state of the stop lamp switch 15 means that a gentle brake operation has been performed. The gentle brake operation means a brake operation that does not exceed a predetermined depression amount set as an end condition of the automatic traveling mode in S44 of FIG.

At S80, stop lamp switch 15
If it is determined that is not turned on, the process is terminated. On the other hand, when it is determined that the stop lamp switch 15 has been turned on, the process proceeds to S82, and the target vehicle speed is reduced. For example, while the brake pedal is being depressed, the target vehicle speed gradually decreases at regular time intervals. Then, after reducing the target vehicle speed, the process returns to S80.

According to the target vehicle speed changing process, when the driver feels that the vehicle speed is high during automatic driving, the vehicle speed can be reduced according to the driver's will, and the driver's discomfort is reduced. it can.

In the target vehicle speed changing process, the reduced target vehicle speed may be stored in a memory as a set value.

For example, as shown in FIG. 11, after the target vehicle speed is reduced (S82), the flow shifts to S84, and the latest target vehicle speed is stored in the memory. By performing such a storage process, it becomes possible to perform automatic traveling adapted to the driving sensation of the driver.

Further, in the target vehicle speed changing process, the speed reduced by braking may be set as the target vehicle speed.

For example, as shown in FIG. 12, when the stop lamp switch 15 is turned on, the flow shifts to S86, and the speed reduced by the driver's brake operation is set as the target vehicle speed.

According to such a target vehicle speed changing process, the driver can set the target vehicle speed according to the actual vehicle speed, so that the target vehicle speed suitable for the driver's own driving feeling can be easily selected.

[0097] The case where the target vehicle speed is reduced has been described as the target vehicle speed changing process. However, the target vehicle speed may be increased.

FIG. 13 is a flowchart of a target vehicle speed changing process when the target vehicle speed is increased.

As shown in S90 of FIG. 13, it is determined whether or not an accelerator operation has been performed. The accelerator operation is, for example, depression of an accelerator pedal by a driver. If it is determined in S90 that there is no accelerator operation, the process ends. On the other hand, when it is determined in S90 that the accelerator operation has been performed, the process proceeds to S92, and the target vehicle speed is increased. For example, while the accelerator pedal is being depressed, the target vehicle speed increases stepwise at regular time intervals. Then, after increasing the target vehicle speed, the process returns to S90.

According to the target vehicle speed changing process, when the driver feels that the speed of the vehicle is low during the automatic driving, the vehicle speed can be increased by the driver's will, and the driver's discomfort is recognized. Can be reduced.

In the target vehicle speed changing process, the increased target vehicle speed may be stored as a set value in a memory.

For example, as shown in FIG. 14, after the target vehicle speed is increased (S92), the flow shifts to S94, and the latest target vehicle speed is stored in the memory. By performing such a storage process, it becomes possible to perform automatic traveling adapted to the driving sensation of the driver.

Further, in the target vehicle speed changing process, the speed increased by operating the accelerator may be used as the target vehicle speed.

For example, as shown in FIG. 15, when there is an accelerator operation, the flow shifts to S96, where the speed increased by the accelerator operation by the driver is set as the target vehicle speed.

According to such a target vehicle speed changing process, the driver can set the target vehicle speed according to the actual vehicle speed, so that the target vehicle speed suitable for the driver's driving sensation can be easily selected.

As described above, according to the traveling control device of the present embodiment, the target vehicle speed can be changed by the driver of the vehicle performing the brake operation or the accelerator operation during the automatic traveling. Therefore, automatic traveling can be performed at a vehicle speed that reflects the driver's intention.

(Third Embodiment) Next, a travel control device according to a third embodiment will be described.

The traveling control device according to the present embodiment has a structure similar to that of the traveling control device 1 according to the first embodiment shown in FIG. Is different in that braking is performed in accordance with the slope in the braking process.

FIG. 16 is a flowchart showing the operation of the travel control device according to this embodiment.

As shown in FIG. 16, it is determined in S10 whether or not the vehicle is in the automatic traveling mode, a target position is determined in S12, a traveling route calculation is performed in S14, and a vehicle stop process is performed in S16. Is performed, an idle-up process is performed in S18, and a traveling start process is performed in S20. These processes in S10 to S20 are performed in the same manner as described in the first embodiment.

Then, after the traveling start processing is completed in S20, the flow shifts to S22, where a slope determination processing is performed. The sloping road determination process is a process of determining whether the traveling road on which the vehicle runs is a sloping road. Details of the slope determination processing will be described later.

After the slope determination process is performed in S22, the process proceeds to S22.
The process proceeds to 30, and a braking control process is performed. This braking control process is performed in substantially the same manner as the braking control process of the first embodiment shown in FIG. 5, but in the braking process of S70, when the traveling road of the vehicle is a sloping road, the braking is performed in consideration thereof. Done.
Details of the braking process will be described later.

Then, after the braking control process is completed in S30, a target vehicle speed changing process is performed in S32, and it is determined in S40 whether or not the vehicle can be driven. If it is determined that the vehicle can be driven, the automatic driving mode is set. It is determined whether or not the end condition is satisfied (S44). On the other hand, when it is determined in S40 that traveling is not possible, a notification process is performed (S4).
8). The target vehicle speed changing process in S32 is performed in the same manner as that described in the second embodiment. Also, S40, S4
4. Each processing of S48 is performed in the same manner as that described in the first embodiment. Then, when the condition for terminating the automatic traveling mode is satisfied in S44 or when the notification process is terminated in S48, the automatic traveling control is terminated.

FIG. 17 shows a flowchart of the slope determination processing.

As shown in S100 of FIG. 17, in the slope determination processing, first, the acceleration of the vehicle is detected. This acceleration may be calculated by differentiating the vehicle speed obtained based on the output signal of the wheel speed sensor 3. Further, an acceleration sensor may be attached to the vehicle, and the detection may be performed based on the output of the acceleration sensor.

Then, the flow shifts to S102, where it is determined whether the acceleration of the vehicle is larger than a preset value B or not. When it is determined that the acceleration of the vehicle is not greater than the set value B, the slope determination processing ends. On the other hand, when it is determined that the acceleration of the vehicle is larger than the set value B, S1
The process proceeds to 04, where it is determined that the traveling path of the vehicle is a downhill slope, and a slope flag is set. Then, the slope determination processing ends.

According to such a slope determination process, it is possible to determine whether or not the traveling road is a downhill slope based on the acceleration state of the vehicle.

In the traveling control device according to the present embodiment, the slope determination processing may be the processing shown in FIGS. 18 and 19 in addition to the processing shown in FIG.

FIGS. 18 and 19 show a flowchart of another slope determination process.

As shown in S110 of FIG. 18, in the slope determination processing, first, a calculation of a vehicle speed deviation is performed. The vehicle speed deviation is calculated by subtracting the actual vehicle speed of the vehicle from a preset target vehicle speed.

Then, the flow shifts to S112, where it is determined whether the actual vehicle speed is higher than the target vehicle speed. When it is determined that the actual vehicle speed is not higher than the target vehicle speed, the slope determination processing ends. On the other hand, when it is determined that the actual vehicle speed is higher than the target vehicle speed, the process proceeds to S114, and it is determined whether the vehicle speed deviation at that time is larger than the set value C.

When it is determined in S114 that the vehicle speed deviation is not larger than the set value C, the slope determination processing ends. On the other hand, when it is determined that the vehicle speed deviation is larger than the set value C, the overshoot of the actual vehicle speed when the vehicle speed exceeds the target vehicle speed for the first time from the start of traveling is large. Shift to set the slope flag. Then, the slope determination processing ends.

According to the slope determination processing shown in FIG. 18, the vehicle speed is low (for example, 0.25 to 3.0 km /
h) The slope determination can be performed reliably even in the case of h), so that it is effective for the slope determination at the time of low-speed running.

By the way, in the slope determination processing of FIG. 19, first, a timer is started (S120). And S12
Then, it is determined whether or not the actual vehicle speed is smaller than a preset value D. When it is determined that the actual vehicle speed is smaller than the set value D, the process proceeds to S124, and the timer measures time. Then, the process returns to S122.

On the other hand, when it is determined in S122 that the actual vehicle speed is not lower than the set value D, the flow shifts to S126, and it is determined whether or not the elapsed time of the timer is shorter than a preset set time T. You. When it is determined that the elapsed time of the timer is not shorter than the set time T, the slope determination processing ends.

On the other hand, when it is determined in S126 that the elapsed time of the timer is shorter than the set time T, it is determined that the vehicle is on a downhill slope because the speed has rapidly increased, and S12 is performed.
Then, the procedure goes to 8 to set the slope flag. Then, the slope determination processing ends.

According to the slope determination processing shown in FIG. 19, as in the slope determination processing shown in FIG. 18, even when the vehicle speed is low (for example, 0.25 to 3.0 km / h), it is ensured. Since slope determination can be performed, it is effective for slope determination during low-speed running.

In the slope determination process in FIGS. 17 to 19, the process of determining whether or not the vehicle is a downhill slope has been described. However, these processes determine whether or not the vehicle is an uphill slope. It can be applied to anything that does. For example, FIG.
19, the acceleration is decelerated in the slope determination processing, so that it is possible to determine whether or not the traveling path of the vehicle is an uphill.

FIG. 20 shows a flowchart of the braking process.

In the braking process, as shown in S150 of FIG. 20, calculation of automatic control brake hydraulic pressure is performed. This automatic control brake hydraulic pressure is calculated based on the integral of the deviation between the actual vehicle speed and the target vehicle speed (see S68 in FIG. 5).

Then, the flow shifts to S152, where it is determined whether the traveling path of the vehicle is a downhill slope. This determination is made based on whether or not the slope flag is set. Then, in S152, when it is determined that the traveling path of the vehicle is not a downhill slope, the automatic control brake hydraulic pressure is set as the target brake hydraulic pressure. And S
The process proceeds to 160.

On the other hand, when it is determined in S152 that the vehicle travels on a downhill, the process proceeds to S156, and the corrected brake hydraulic pressure is calculated. The corrected brake hydraulic pressure is calculated by subtracting a default acceleration, which is a predetermined value, from the acceleration of the vehicle and multiplying the difference by a predetermined coefficient. Here, the predetermined coefficient is a coefficient for converting acceleration into oil pressure.

Then, the flow shifts to S158, where the sum of the automatic control brake hydraulic pressure and the correction brake hydraulic pressure is set as the target brake hydraulic pressure. And S160
The control signal corresponding to the target brake hydraulic pressure is output to the brake hydraulic actuator 4. Accordingly, the brake hydraulic actuator 4 operates according to the control signal, and a braking force is applied to the vehicle. Then, the braking process ends.

FIG. 21 is a block diagram of an automatic traveling control system in the traveling control device according to the present embodiment.

As shown in FIG. 21, in the traveling control device according to the present embodiment, the braking control is performed by adding the target brake hydraulic pressure, which is obtained by differentiating the actual vehicle speed, detecting the acceleration and correcting the slope, to the brake hydraulic actuator 4. For this reason, the braking controllability on a traveling road that is not a sloping road is superior to the case where no sloping road correction is performed. For example, if the vehicle is provided with a normal braking force when the vehicle is not on a slope, the vehicle may be greatly accelerated and sufficient braking force may not be secured, and the target vehicle speed may temporarily exceed the target vehicle speed. . On the other hand, by performing the slope correction, it is possible to control the vehicle at a position close to the target vehicle speed without greatly exceeding the target vehicle speed due to the slope, thereby enabling stable automatic traveling.

As shown in FIG. 22, the traveling control device according to this embodiment detects the acceleration by differentiating the actual vehicle speed, determines the slope based on the acceleration, and determines whether the vehicle is on a slope or not. Alternatively, a constant correction value may be added to the automatic control brake oil pressure to follow the target vehicle speed.

Further, as shown in FIG. 23, the traveling control device according to the present embodiment determines whether or not the vehicle is on a slope based on a vehicle speed deviation, and, based on the determination result, a controller having an integrator and a gain. May be corrected to obtain the target vehicle speed.

Even with the traveling control device having the control system shown in FIGS. 22 and 23, the same operation and effect as those of the traveling control device having the control system shown in FIG. 21 can be obtained.

As described above, according to the traveling control device of the present embodiment, it is possible to determine whether or not the traveling path on which the vehicle automatically travels is a sloping road. Vehicle running becomes possible.

(Fourth Embodiment) Next, a travel control device according to a fourth embodiment will be described.

The traveling control device according to the present embodiment has substantially the same configuration as the traveling control device according to the first embodiment. However, while detecting the wheel speed by the electromagnetic pickup type wheel speed sensor 3, The difference is that the vehicle speed can be accurately detected even at a low speed.

FIG. 24 shows a flowchart of a braking control process in the traveling control device according to the present embodiment. In addition, the automatic traveling control in the traveling control device according to the present embodiment includes:
The operation is performed in the same manner as the travel control device according to the first embodiment shown in FIG.

As shown in FIG. 24, in the braking control process in the traveling control device according to the present embodiment, first, the wheel speed is read in S60. The reading of the wheel speed is performed based on the output of the wheel speed sensor 3 of the electromagnetic pickup type. Then, the flow shifts to S61, where reading of brake hydraulic pressure is performed. The reading of the brake oil pressure is, for example,
This is performed based on the output of the oil pressure sensor.

Then, the flow shifts to S63, where the actual vehicle speed of the vehicle is calculated based on the wheel speed and the brake hydraulic pressure. For example, assuming that the actual vehicle speed is V, the actual vehicle speed V is calculated by the following equation (1). V = Vw + at × (1)

Here, Vw is the read data of the wheel speed, a is the acceleration (including the case of deceleration) based on the read data of the brake oil pressure, and t is the time from the reading of the wheel speed Vw.

Then, the flow shifts to S64, where a deviation between the actual vehicle speed and a preset target vehicle speed is calculated. And S6
6 and the calculated deviation is set to a preset value A.
It is determined whether it is greater than. When it is determined that the deviation is not larger than the set value A, the braking control process ends. On the other hand, when it is determined that the deviation is larger than the set value A, the flow shifts to S68, and the deviation integration processing is performed.

Then, the flow shifts to S70, where a control signal based on the integrated deviation is output from the ECU 2 to the brake hydraulic actuator 4, and a braking force is applied to the vehicle by the operation of the brake hydraulic actuator 4. Then, the braking control process ends.

According to such braking control processing, S63
Since the actual vehicle speed can be calculated at a constant calculation cycle t, even when the wheel speed is detected by using the wheel speed sensor 3 of the electromagnetic pickup type, the actual vehicle speed can be calculated accurately during low-speed traveling. .

For example, as shown in FIG. 25, when the abscissa represents time and the ordinate represents vehicle speed, when the wheel speed is detected using the wheel speed sensor 3 of the electromagnetic pickup type, as the vehicle speed becomes slower. As a result, the rotation of the gear-shaped rotor also becomes slow, and the reading interval tw of the wheel speed Vw becomes long. Therefore, if the actual vehicle speed is calculated based only on the wheel speed Vw, the update cycle becomes longer at a very low speed, and the accuracy of the actual vehicle speed decreases.

Therefore, in the traveling control device according to the present embodiment, the wheel speed Vw is calculated by multiplying the elapsed time t from the reading of the wheel speed Vw by the acceleration a based on the reading data of the brake oil pressure (at). With the addition, the actual vehicle speed can be calculated at an interval shorter than the reading interval tw of the wheel speed Vw. Therefore, it is possible to accurately calculate the actual vehicle speed of the vehicle.

As described above, according to the traveling control apparatus of the present embodiment, based on the wheel speed Vw of the wheel speed sensor 3 output in accordance with the actual vehicle speed of the vehicle and the brake hydraulic pressure as the braking control amount. By detecting the actual vehicle speed, detection accuracy of the actual vehicle speed can be improved.

(Fifth Embodiment) Next, a travel control device according to a fifth embodiment will be described.

The travel control device according to this embodiment has substantially the same configuration as the travel control device according to the first embodiment, but determines whether or not the vehicle travels on a low μ road. The difference is that the target vehicle speed is changed or anti-lock control is performed according to the determination result.

FIG. 26 shows a flowchart of the automatic traveling control in the traveling control device according to the present embodiment. As shown in FIG. 26, it is determined whether or not the vehicle is in the automatic traveling mode in S10, a target position is determined in S12, a traveling route calculation is performed in S14, and a vehicle stop process is performed in S16. , S18, an idle-up process is performed, and a traveling start process is performed in S20. These processes in S10 to S20 are performed in the same manner as described in the first embodiment.

Then, after the traveling start processing is completed in S20, the flow shifts to S24, where low μ road processing is performed. The low μ road process is a process of determining whether or not the traveling road of the vehicle is a low μ road, and changing the target vehicle speed according to the determination result. Details of the low μ road processing will be described later.

After the low-μ road processing is performed in S24, S3
The process proceeds to 0, and the braking control process is performed. This braking control process is performed in the same manner as the braking control process of the first embodiment shown in FIG. Then, a target vehicle speed changing process is performed in S32, and it is determined in S40 whether or not the vehicle can be driven. If it is determined that the vehicle can be driven, it is determined whether or not the end condition of the automatic driving mode is satisfied. (S44). On the other hand, S40
When it is determined that the vehicle cannot travel, the notification process is performed (S48). The target vehicle speed changing process in S32 is performed in the same manner as that described in the second embodiment. Also, S
Each processing of S40, S44, and S48 is performed in the same manner as that described in the first embodiment. Then, when the condition for terminating the automatic traveling mode is satisfied in S44 or when the notification process is terminated in S48, the automatic traveling control is terminated.

FIG. 27 is a flowchart of the low-μ road processing.

In the low μ road process, as shown in FIG. 27, first, in S180, it is determined whether or not the traveling road of the vehicle is a low μ road. The determination as to whether the vehicle is on a low μ road is made based on the wheel speed detected by the wheel speed sensor 3 and the like. If it is determined in S180 that the traveling road of the vehicle is not a low μ road, the process ends.

On the other hand, when it is determined in S180 that the traveling road of the vehicle is a low μ road, the flow shifts to S182, and the target vehicle speed is changed to a low speed. For example, a value obtained by multiplying the current target vehicle speed by a coefficient α larger than zero and smaller than 1 is set as the target vehicle speed. Then, the process ends.

According to such low μ road processing, even when the vehicle travels on a low μ road and the braking performance of the vehicle is reduced, the target vehicle speed is set to a low value. Can be secured.

In the travel control device according to the present embodiment, it is desirable that antilock control be performed under certain conditions when the travel road is a low μ road.

FIG. 28 shows a flowchart of the braking process.

As shown in S200 of FIG. 28, in the braking process, first, the calculation of the wheel speed is performed. And S202
Then, the calculation of the vehicle speed is performed. The vehicle speed is calculated by estimating the vehicle speed based on the wheel speed.

Then, the flow shifts to S204, where it is determined whether the traveling route of the vehicle is a low μ road or not. When it is determined that the traveling road of the vehicle is a low μ road, the process proceeds to S206, and the slip ratio is calculated. Then, it is determined whether the slip ratio is smaller than the set value β (S20).
8). The set value β is set to 0 <β <1.

When it is determined in S208 that the slip ratio is not smaller than the set value β, the flow shifts to S214, where antilock control is performed. On the other hand, when it is determined in S208 that the slip ratio is smaller than the set value β, the yaw rate is detected (S210). And S21
Then, it is determined whether the wheel speed is zero and the yaw rate is smaller than the set value γ.

In S212, the wheel speed is zero, and
When it is determined that the yaw rate is smaller than the set value γ, the process proceeds to S216. On the other hand, when it is determined in S212 that the wheel speed is not zero or the yaw rate is not smaller than the set value γ, the process proceeds to S214.

When it is determined in S204 that the vehicle is not running on a low μ road, the flow proceeds to S216, 218.
Then, the normal braking process is performed. That is, the automatic control brake hydraulic pressure is calculated, and a control signal corresponding to the calculated automatic control brake hydraulic pressure is output to the brake hydraulic actuator 4. Accordingly, the brake hydraulic actuator 4 operates according to the control signal, and a braking force is applied to the vehicle. Then, the braking process ends.

As described above, according to the traveling control device of this embodiment, the road surface condition of the traveling road is detected, and the target vehicle speed is reduced when the traveling road is a low μ road. Slip is prevented and the safety of automatic driving can be ensured.

By performing antilock control when the slip ratio of the vehicle becomes larger than the set value, slip during automatic running can be prevented, and safety of automatic running can be ensured.

(Sixth Embodiment) Next, a travel control device according to a sixth embodiment will be described.

The traveling control device according to the present embodiment has substantially the same configuration as the traveling control device according to the first embodiment, except that a braking force is applied to the vehicle using a parking brake when the vehicle is stopped. Is different.

FIG. 29 shows a flowchart of the vehicle stop processing in the travel control device according to the present embodiment. As shown in FIG. 29, in the vehicle stop processing, in S300, a brake motor (not shown) is driven, a pump (not shown) of a brake system is operated, and the brake oil pressure is increased.

Then, the flow shifts to S302, where an electric parking brake (electric PKB) is operated, and a braking force is applied to the vehicle. Then, the flow shifts to S304, where the brake motor is stopped. Then, the vehicle stop processing ends.

According to the vehicle stop processing, it is not necessary to continue driving the brake motor to secure the brake oil pressure. Therefore, the motor current is prevented from being consumed for a long time, and the durability of the motor is improved and the current consumption of the battery is reduced.

In the case where the vehicle is not equipped with an electric parking brake but is equipped with a manual parking brake, in the vehicle stop processing, when the brake oil pressure is increased and when the parking brake is applied, By stopping the motor at
It is possible to prevent the motor current from being consumed for a long time, thereby improving the durability of the motor and reducing the current consumption of the battery.

(Seventh Embodiment) Next, a travel control device according to a seventh embodiment will be described.

The traveling control device according to the present embodiment has substantially the same configuration as the traveling control device according to the first embodiment, except that the output of a predetermined electric device mounted on the vehicle during the automatic traveling mode is controlled. This is different from the first embodiment in that output suppression means for suppressing the above is provided.

FIG. 30 is a flowchart showing the operation of the travel control device according to this embodiment. As shown in FIG. 30, in the traveling control device according to the present embodiment, an output suppression process is performed before the braking control process (S30) (S2).
6).

The output suppressing process is a process for suppressing the output of a high-load electric component such as an air conditioner or an audio amplifier so that the driving force of the vehicle does not fluctuate. For example, during automatic driving, the output of electric components such as an air conditioner and an audio amplifier is reduced. As a result, a constant driving power of the vehicle can be secured.

As described above, according to the travel control device of the present embodiment, it is possible to suppress deterioration of the power balance during automatic travel.

(Eighth Embodiment) Next, a travel control device according to an eighth embodiment will be described.

The travel control device according to the present embodiment has substantially the same configuration as the travel control device according to the first embodiment, except that the output of a predetermined electric device mounted on the vehicle during the automatic travel mode is controlled. In that engine rotation control means for increasing the engine rotation speed in accordance with the engine speed is provided.

FIG. 31 is a flowchart showing the operation of the travel control device according to this embodiment. As shown in FIG. 31, in the travel control device according to the present embodiment, an engine rotation control process is performed (S28) before the braking control process (S30).

The engine speed control process is a process for increasing the engine speed in accordance with the increase in the electric load so that the driving force of the vehicle does not fluctuate. For example, when the electric load increases due to the operation of an air conditioner or a generator for driving a gear, the engine speed is increased in accordance with the increase in the electric load. As a result, even when the output of the electric device increases, a constant driving force for driving the vehicle can be secured.

As described above, according to the traveling control device of the present embodiment, it is possible to suppress the deterioration of the power balance during automatic traveling.

In the above-described first to eighth embodiments, the automatic parking device has been described as an example. However, the travel control device according to the present invention is not limited to these embodiments. Alternatively, the present invention may be applied to a parking assist system in which a driver performs a parking operation while receiving a guide such as a target locus or a steering angle by voice or low-speed traveling such as traffic congestion. In this way, even during low-speed traveling with frequent acceleration / deceleration, low-speed traveling at or below the target vehicle speed can be easily performed by operating only the brake pedal.

(Ninth Embodiment) Next, a travel control device according to a ninth embodiment will be described.

The traveling control device according to the present embodiment adjusts the vehicle speed of the vehicle by the driver's brake operation, and automatically accelerates / decelerates the vehicle speed so as to reach the target vehicle speed at that point. It is different from the travel control device according to the embodiment to the eighth embodiment.

FIG. 32 is a schematic diagram of the configuration of a travel control device according to this embodiment. As shown in the figure, the traveling control device 1 is provided with a slow traveling mode switch 12a. The slow running mode switch 12a is a switch for setting a slow running mode in which the vehicle runs at a slow speed.

Here, the "slow running mode" refers to a mode in which the vehicle can run at a slow speed without an accelerator operation by a predetermined driving force that is somewhat higher than the driving torque (creep torque) at the time of idling. The slow speed mentioned here means the vehicle speed when the vehicle travels on a flat road by operating the brake pedal without operating the accelerator pedal under the predetermined driving force, for example, under the predetermined driving force. If the vehicle travels on a flat road without stepping on the brake, the vehicle speed becomes 20 km / h, which means a vehicle speed region of about 20 km / h or less.

When the slow running mode switch 12a is turned on, the vehicle enters the slow running mode, and the slow running is performed.

Next, the operation of the travel control device according to this embodiment will be described.

FIG. 33 is a flowchart showing the operation of the travel control device according to the present embodiment. As shown in S400 in the figure, it is determined whether or not the vehicle is in the slow running mode.

In the slow running mode, the slow running switch 12
a is turned on, and the actual vehicle speed V of the vehicle is a predetermined speed V1.
It is started by: Predetermined speed V1
Is a speed set in advance in the ECU 2, and is a speed equal to or lower than the vehicle speed when traveling on a flat road without operating the accelerator and the brake under the above-described predetermined driving force, that is, on a flat road in the slow traveling mode. Is set to a value within the speed range when traveling.

In this embodiment, the predetermined driving force in the reverse direction is set smaller than that in the forward direction, and the vehicle travels on a flat road under the predetermined driving force in the forward direction when the brake is not depressed. Then, the vehicle speed becomes about 20km / h,
When traveling on a flat road under a predetermined driving force in the reverse direction, about 1
The vehicle speed is 0 km / h. Therefore, the predetermined speed V1 in the forward direction is 10 km / h as a value of 20 km / h or less.
h, the predetermined speed V1 in the reverse direction is set to 5 km / h as a value of 10 km / h or less.

At this time, instead of turning on the slow traveling switch 12a, another operation may be used as one of the conditions for starting the slow traveling mode. For example, the start condition of the slow traveling mode may be that the brake pedal is depressed, the vehicle speed is substantially zero, and the transmission is switched from the forward state to the reverse state or from the reverse state to the forward state. It is.

If it is determined in S400 that the vehicle is not in the slow running mode, the control process is terminated. On the other hand, when it is determined in S400 that the vehicle is in the slow running mode, the flow shifts to S402 and idle-up processing is performed. The idle-up process is a process of outputting a control signal from the ECU 2 to the engine 6 and increasing the rotation speed of the engine 6 to a rotation speed larger than the rotation speed at idling so as to generate a predetermined driving force somewhat higher than the creep torque. It is.

By performing this idle-up,
The rotation speed of the engine 6 becomes higher than at the time of idling, a predetermined driving force is continuously applied to the vehicle, and the vehicle can run at a slow speed. When the driver is performing a brake operation while the vehicle is running at a slow speed, the running speed of the vehicle can be adjusted within a predetermined driving force range. During idle-up, when the driver is depressing the brake pedal and the vehicle is stopped, the vehicle starts running at a slow speed by releasing the brake pedal.

Then, the flow shifts to S404, where it is determined whether the actual vehicle speed V is equal to or higher than the set speed V2. Set speed V
Reference numeral 2 denotes a speed preset in the ECU 2, which is set as a value obtained by adding a predetermined hysteresis to a vehicle speed when traveling on a flat road without depressing a brake in the slow running mode as an upper limit speed in the slow running mode. . In the present embodiment, when the vehicle travels on a flat road with the brake turned off under a predetermined driving force in the forward direction, the vehicle speed becomes approximately 20 km / h,
About 10 running on a flat road under a predetermined driving force in the reverse direction
The vehicle speed is km / h. Therefore, the set speed V2 in the forward direction is set to 22 km / h obtained by adding 10% as a predetermined hysteresis to 20 km / h, and the set speed V2 in the reverse direction is set to 10 km / h as a predetermined hysteresis. % Is set to 11 km / h.

When it is determined that the actual vehicle speed V is not higher than the set speed V2, the flow shifts to S410. On the other hand, actual vehicle speed V
Is determined to be equal to or higher than the set speed V2, S4
The process proceeds to 06, where a braking control process is performed.

In the braking control process, the vehicle speed of the vehicle is adjusted to the set speed V
This is a process for forcibly applying a brake so as to be slower than 2. That is, a control signal is output from the ECU 2 to the brake hydraulic actuator 4, and the brake hydraulic actuator 4 is operated to brake the vehicle so that the actual vehicle speed V of the vehicle becomes lower than the set speed V2.

Then, the flow shifts to S408, where a warning process is performed. The warning process is a process of notifying the driver that the forcible braking is being performed, and is performed, for example, through display of an instrument panel, generation of a signal sound or a sound, or the like. Then, the flow shifts to S410, where it is determined whether a condition for releasing the slow running mode is satisfied. The slow running mode release condition corresponds to, for example, turning off of the slow running mode switch 12a.

If it is determined in S410 that the condition for releasing the slow running mode is not satisfied, the flow returns to S404. On the other hand, when it is determined that the condition for releasing the slow running mode is satisfied, the control process is terminated.

FIG. 34 is a timing chart of the operation of the travel control device according to this embodiment.

As the idle-up state continues, a predetermined driving force is continuously applied to the vehicle.
In this state, as shown in FIG. 34, when the driver gradually releases the brake pedal, the brake hydraulic pressure gradually decreases,
Accordingly, the vehicle speed V gradually increases.

At this time, the actual vehicle speed V of the vehicle becomes higher than the predetermined speed V2, for example, when the traveling road surface of the vehicle is downhill. At this time, even if the driver does not operate the brake, the braking control is forcibly performed, and the actual vehicle speed V of the vehicle becomes the predetermined speed V
The vehicle speed is adjusted to be slower than 2. Further, during the braking control, the driver is warned to that effect. Therefore, even if a predetermined driving force is continuously applied to the vehicle, it is possible to prevent the vehicle speed from becoming too fast due to a road surface condition or the like.

As described above, according to the traveling control device of the present embodiment, when the vehicle is in the slow traveling mode, the number of revolutions of the engine 6 is increased from that at the time of idling, and the driving force of the vehicle is set to the predetermined driving force. By maintaining this, when the vehicle travels, the driving force of the vehicle does not increase even if the traveling resistance increases due to the conditions of the traveling path. For this reason, when there is an obstacle such as a curb in the traveling route, it is possible to prevent inappropriate traveling such as the vehicle traveling over the obstacle forcibly. Also,
If there is an obstacle in the travel route, the vehicle speed will decrease,
As a result, the driver of the vehicle can sense a running abnormality, and inappropriate running can be prevented beforehand by the brake operation.

The actual vehicle speed V of the vehicle is equal to a predetermined set speed V
By performing the braking control so as not to be 2 or more, it is possible to prevent the vehicle speed from becoming too high due to the state of the traveling road surface such as when the traveling road is downhill.

Further, in the braking control, by performing the braking of the vehicle using the brake 5, the vehicle speed can be adjusted accurately, unlike the case where the engine output is reduced and the driving force of the vehicle is controlled. In particular, the vehicle speed can be accurately adjusted at the time of slow running.

In the travel control device according to the present embodiment, as shown in FIG. 32, the image processing unit 7, the rear camera 8, the side cameras 9, 10, the display unit 11, the parking position input unit 13, the steering drive Although the unit 14 is not provided, the unit may be provided to perform a target position determination, a travel route calculation, and the like (see FIG. 2) as in the travel control device shown in FIG.

Further, in the present embodiment, S40 in FIG.
6, the actual vehicle speed V is equal to the set speed V2.
When it becomes above, the brake is forcibly applied and the actual vehicle speed V
Is braked to be lower than the set speed V2, but the set speed V3 is set lower than the set speed V2, and the actual vehicle speed V
Is preferably lower than the set speed V3 as a condition for terminating the braking control.

For example, as shown in FIG.
2, a preset speed V3 lower than the preset speed V2 is set in advance, and when the actual vehicle speed V exceeds the preset speed V2 is set as a start condition of the braking control, and when the actual vehicle speed V falls below the set speed V3 is set as an end condition of the brake control. By setting the conditions in this way,
The on / off feeling of the braking control can be reduced, and the riding comfort during slow running can be improved.

In this embodiment, the vehicle speed when traveling on a flat road without stepping on the brake in the slow traveling mode, that is, 20 km / h in the forward direction and 10 km / h in the reverse direction is set as the set speed V3. By setting in this way, it is possible to smoothly connect the braking control state on a downhill and the slow speed mode traveling on a flat road.

In addition, the braking control based on exceeding the set speed V2 when the accelerator is depressed may be prohibited so that the driver can accelerate when the driver intentionally depresses the accelerator. Also in this case, when the depression of the accelerator is released, the braking control is executed until the vehicle speed decreases to the set speed V3, so that traveling in the slow traveling mode is possible. However, when the driver accelerates to a vehicle speed considerably higher than the set speed V2, it is considered that the necessity of slow running has already been reduced, and the set speed V2
A higher set speed V4 is set in advance, and if the actual vehicle speed exceeds the set speed V4 by depressing the accelerator pedal of the driver, the slow traveling mode is automatically released, and the driver is notified of the release. It may be. For example,
It is desirable to set the set speed V4 to 40 km / h only in the forward direction so that the vehicle can automatically shift to the normal running when the traffic congestion is resolved.

The braking control processing in this embodiment (FIG. 33)
In S406), a future actual vehicle speed may be predicted based on the change in the actual vehicle speed V, and braking may be forcibly performed when the actual vehicle speed becomes equal to or higher than the set speed V2. For example, by adding a value obtained by multiplying the current vehicle speed V by the current acceleration by τ, the vehicle speed Vτ after τ seconds is calculated, and when the vehicle speed Vτ reaches the set speed V2, braking is forcibly performed in advance. . By doing so, the vehicle speed can be reduced beforehand, so that a sudden change in the behavior of the vehicle due to the braking control can be prevented.

[0216]

As described above, according to the present invention, by controlling the braking force of the vehicle and adjusting the traveling speed of the vehicle to perform automatic traveling in a state where the engine rotational speed is set to a predetermined rotational speed, It is possible to prevent improper traveling such as a case where the vehicle forcibly runs over the obstacle when the traveling path has an obstacle.

Also, by integrating the deviation between the actual vehicle speed and the target vehicle speed and controlling the braking force of the vehicle based on the integration result, the vehicle automatically runs at a low speed and the time interval for detecting the vehicle speed becomes longer, and the vehicle speed becomes longer. Hunting of the vehicle can be suppressed as compared with the case where the deviation is proportionally processed, even when the update cycle of is longer.

Further, by stopping the vehicle by applying a braking force before running the vehicle, it is possible to accurately follow a predetermined traveling route when the vehicle is automatically driven. In particular, it is useful when employed in an automatic parking device or the like.

Further, by changing the target vehicle speed according to the acceleration / deceleration operation of the driver of the vehicle, it becomes possible to automatically drive at a vehicle speed reflecting the driver's will.

Further, when the driver depresses the brake pedal by a predetermined amount or more during the automatic driving, the automatic driving mode is released, thereby forcibly terminating the automatic driving through the braking operation of the driver by the predetermined amount or more. Can be.

When the vehicle is in the automatic driving mode, the driver releases the brake pedal and then drives the vehicle, so that automatic driving can be started through the driver's braking operation.

Further, when the vehicle is driven automatically, the vehicle can be prevented from suddenly starting by gradually reducing the braking force to drive the vehicle.

Further, when the vehicle is running, a braking force is applied to the vehicle through a hydraulic braking mechanism, and when the vehicle is stopped, a braking force is applied to the vehicle through a mechanical braking mechanism. There is no need to generate hydraulic pressure for Therefore, energy consumption for applying the braking force can be reduced.

Further, the vehicle is provided with a slope determination means for determining whether or not the vehicle travels on a sloping road. When the vehicle travels on a sloping road, the vehicle is controlled by taking into account the hills. It is possible to determine whether or not the traveling path for automatic traveling is a sloping road, and even when the traveling path is a sloping road, appropriate vehicle traveling can be performed by braking control according to the sloping road.

Further, by providing vehicle speed detecting means for detecting the actual vehicle speed of the vehicle based on the wheel speed output in a cycle corresponding to the actual vehicle speed of the vehicle and the braking control amount, the vehicle is traveling at a low speed. Even if the pulse signal cycle corresponding to the above becomes longer, the calculation of the actual speed can be complemented based on the acceleration / deceleration due to braking, and the detection accuracy of the actual vehicle speed can be improved.

Further, a target vehicle speed changing means for lowering the target vehicle speed when the traveling road is a low μ road is provided, and anti-lock control is performed when the slip ratio of the vehicle is larger than a set value, so that the automatic driving is performed during automatic traveling. Slip is prevented and the safety of automatic driving can be ensured.

Further, by providing output suppressing means for suppressing the output of predetermined electric equipment mounted on the vehicle when the vehicle enters the automatic driving mode, it is possible to suppress the deterioration of the power balance during automatic driving. it can.

Further, when the vehicle is running, the running resistance is increased by the running road condition by performing the running control while maintaining the driving force of the vehicle at a predetermined driving force in the slow running mode. However, the driving force of the vehicle does not increase. For this reason, even when there is an obstacle on the traveling path, it is possible to prevent improper traveling such as the vehicle traveling over the obstacle forcibly. Further, when the vehicle tries to get on an obstacle on the traveling path, the vehicle speed decreases, so that the driver of the vehicle can detect a traveling abnormality and prevent an inappropriate traveling by a brake operation.

Further, by performing the braking control so that the actual vehicle speed of the vehicle does not exceed the predetermined set speed, it is possible to prevent the vehicle speed from becoming too high due to the state of the traveling road such as when the traveling road is downhill. it can.

Further, a future actual vehicle speed is predicted based on a change in the actual vehicle speed of the vehicle, and the vehicle braking control is performed so that the future actual vehicle speed does not exceed a predetermined set speed, thereby lowering the vehicle speed beforehand. This makes it possible to prevent the behavior of the vehicle from suddenly changing due to the braking control.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a traveling control device according to a first embodiment.

FIG. 2 is a flowchart showing an operation of the traveling control device of FIG.

FIG. 3 is a flowchart illustrating an example of a traveling start process in the traveling control device of FIG. 1;

FIG. 4 shows a timing chart of brake hydraulic pressure and braking in the traveling control device of FIG.

FIG. 5 is a flowchart illustrating an example of a braking control process in the traveling control device of FIG. 1;

FIG. 6 is an explanatory diagram of an integrator in the traveling control device of FIG. 1;

FIG. 7 is an explanatory diagram of an integrator in the traveling control device of FIG.

FIG. 8 is a block diagram of a control system in the traveling control device of FIG. 1;

FIG. 9 is a flowchart showing the operation of the travel control device according to the second embodiment.

FIG. 10 is a flowchart illustrating an example of a target vehicle speed changing process in the traveling control device of FIG. 9;

FIG. 11 is a flowchart illustrating an example of a target vehicle speed changing process in the traveling control device of FIG. 9;

FIG. 12 is a flowchart illustrating an example of a target vehicle speed changing process in the traveling control device of FIG. 9;

FIG. 13 is a flowchart illustrating an example of a target vehicle speed changing process in the traveling control device of FIG. 9;

FIG. 14 is a flowchart illustrating an example of a target vehicle speed changing process in the traveling control device of FIG. 9;

FIG. 15 is a flowchart illustrating an example of a target vehicle speed changing process in the traveling control device of FIG. 9;

FIG. 16 is a flowchart illustrating an operation of the travel control device according to the third embodiment.

FIG. 17 is a flowchart illustrating an example of a slope determination process in the traveling control device of FIG. 16;

FIG. 18 is a flowchart illustrating an example of a slope determination process in the traveling control device of FIG. 16;

FIG. 19 is a flowchart illustrating an example of a slope determination process in the traveling control device of FIG. 16;

FIG. 20 is a flowchart illustrating an example of a braking process in the traveling control device of FIG. 16;

21 is a block diagram of a control system in the traveling control device of FIG.

FIG. 22 is a block diagram of a control system in the traveling control device of FIG.

FIG. 23 is a block diagram of a control system in the traveling control device of FIG.

FIG. 24 is a flowchart of a braking control process in the traveling control device according to the fourth embodiment.

25 is an explanatory diagram of actual vehicle speed detection in the travel control device of FIG. 24.

FIG. 26 is a flowchart of a braking control process in the traveling control device according to the fifth embodiment.

FIG. 27 is a flowchart of a low-μ road process in the traveling control device of FIG. 26;

FIG. 28 is a flowchart of a braking process in the traveling control device of FIG. 26;

FIG. 29 is a flowchart of a vehicle stop process in a traveling control device according to a sixth embodiment.

FIG. 30 is a flowchart showing the operation of the travel control device according to the seventh embodiment.

FIG. 31 is a flowchart showing the operation of the travel control device according to the eighth embodiment.

FIG. 32 is an explanatory diagram of a traveling control device according to a ninth embodiment.

FIG. 33 is a flowchart showing the operation of the travel control device according to the ninth embodiment.

FIG. 34 is a timing chart in the operation of the traveling control device according to the ninth embodiment.

FIG. 35 is an explanatory diagram of a modified example of the traveling control device according to the ninth embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Travel control device, 2 ... ECU, 3 ... Wheel speed sensor, 4
... brake hydraulic actuator, 6 ... engine.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B60R 21/00 621 B60R 21/00 621C 622 622F 624 624G 626 626A 627 627 B60T 7/12 B60T 7/12 F F02D 41/14 320 F02D 41/14 320D 41/16 41/16 PF term (reference) 3D041 AA12 AA23 AA33 AA37 AA38 AA41 AA45 AA66 AA71 AA76 AA77 AA79 AB01 AC04 AC26 AD02 AD04 AD06 AD10 AD11 AD41 AD51 AE03 AE04 AE04 AE04 AE04 AE04 AF01 3D044 AA01 AA18 AA21 AA24 AA45 AB01 AC03 AC05 AC16 AC24 AC27 AD02 AD04 AD12 AD21 AE03 AE04 AE21 3D046 BB17 BB23 BB28 CC01 CC02 EE01 EE02 GG02 GG10 HH02 HH05 HH16 HH20 HH23 HH26 HH36 HH46 HH49 JJ05 JJ06 KK08 KK11 MM34 3G093 AA01 BA04 BA07 BA09 BA15 BA23 CA04 CA06 CA10 CB02 CB11 CB12 DA01 DB01 DB05 DB15 EA01 EA03 EA09 EB04 EC01 FA04 FA07 3G301 JA03 JA11 JA35 KA07 KA08 KA21 KA24 KB02 KB04 LA01 LC01 ND02 NE01 PA11A PE01A PF01A PF03A PF05A

Claims (24)

[Claims] 1. A travel control device mounted on a vehicle capable of automatic travel and performing automatic travel control thereof, comprising: an automatic travel determination unit configured to determine whether the vehicle is in an automatic travel mode; When it is determined that the vehicle has entered the automatic driving mode, a rotation speed increasing unit that increases the rotation speed of the engine to a predetermined rotation speed that is greater than at the time of idling, and the vehicle is driven at the predetermined rotation speed. And a braking control means for controlling a braking force of the vehicle such that an actual vehicle speed of the vehicle becomes a preset target vehicle speed. 2. A release means for releasing the automatic driving mode when the vehicle cannot run with the driving force at the predetermined rotation speed when the vehicle is to run at the predetermined rotation speed. The travel control device according to claim 1, wherein: 3. The traveling system according to claim 2, further comprising: a notifying unit for notifying the driver of the vehicle of the release information when the automatic driving mode is released by the releasing unit. Control device. 4. A vehicle speed detecting means for detecting an actual vehicle speed of the vehicle, wherein the braking control means integrates a deviation between the actual vehicle speed detected by the vehicle speed detecting means and the target vehicle speed, and calculates an integration result. The travel control device according to any one of claims 1 to 3, wherein a braking force of the vehicle is controlled so that an actual vehicle speed of the vehicle becomes the target vehicle speed based on the vehicle speed. 5. A vehicle stopping means for applying a braking force to the vehicle to stop the vehicle before driving the vehicle at the predetermined rotation speed.
The travel control device according to any one of claims 1 to 4. 6. The travel control device according to claim 1, further comprising a target vehicle speed changing unit that changes the target vehicle speed according to an acceleration / deceleration operation of a driver of the vehicle. 7. The travel control device according to claim 6, wherein the target vehicle speed changing means decreases the target vehicle speed by operating a brake pedal of the driver. 8. The target vehicle speed changing means sets the target vehicle speed to zero when the driver depresses the brake pedal by a predetermined amount or more.
The travel control device according to claim 1. 9. The travel control device according to claim 6, wherein the target vehicle speed changing means increases the target vehicle speed by an accelerator operation of the driver. 10. The automatic driving mode is canceled when a driver of the vehicle depresses the brake pedal by a predetermined amount or more while the vehicle is in the automatic driving mode. The travel control device according to any one of claims 1 to 7. 11. The vehicle according to claim 1, wherein when the vehicle enters the automatic driving mode, the driver of the vehicle releases the brake pedal and then drives the vehicle.
The travel control device according to any one of claims 10 to 10. 12. The vehicle according to claim 1, wherein the braking control means causes the vehicle to travel by gradually reducing the braking force of the vehicle when the vehicle travels at the predetermined rotation speed. A travel control device according to any one of claims 11 to 13. 13. The vehicle according to claim 1, wherein a braking force is applied to the vehicle through a hydraulic braking mechanism when the vehicle travels, and a braking force is applied to the vehicle through a mechanical braking mechanism when the vehicle stops traveling. The travel control device according to any one of 1 to 12. 14. A hill determining means for determining whether or not a running road of the vehicle is a hill based on an acceleration state of the vehicle when the vehicle is run with the engine at the predetermined rotation speed. 14. The method according to claim 1, wherein
The travel control device according to any one of the above. 15. The vehicle control system according to claim 15, wherein the braking control means subtracts an acceleration due to a driving force of the vehicle from the acceleration of the vehicle when the traveling road of the vehicle is determined to be the slope by the slope determining means. The travel control device according to claim 14, wherein is added to the control amount as a braking force. 16. When the vehicle is run with the engine set to the predetermined rotational speed, the vehicle is driven based on an overshoot of the actual vehicle speed when the vehicle speed exceeds the target vehicle speed for the first time from the start of the vehicle. The travel control device according to any one of claims 1 to 13, further comprising a slope determination unit that determines whether or not the travel road is a slope. 17. The braking control means controls a braking force with a predetermined control amount according to the overshoot when the hill determining means determines that the traveling path of the vehicle is the hill. The traveling control device according to claim 16, wherein the driving is performed. 18. A vehicle speed detecting means for detecting the actual vehicle speed of the vehicle based on a wheel speed and a braking control amount output in a cycle corresponding to the actual vehicle speed of the vehicle. The travel control device according to any one of 1 to 17. 19. A vehicle comprising: a road surface state detecting means for detecting a road surface state of a traveling road on which the vehicle travels automatically; and a target vehicle speed changing means for decreasing the target vehicle speed when the traveling road is a low μ road. Claim 1 to claim
19. The travel control device according to any one of 18. 20. The travel control device according to claim 19, wherein the antilock control is performed when the slip ratio of the vehicle is larger than a set value. 21. An apparatus according to claim 1, further comprising output suppression means for suppressing output of predetermined electric equipment mounted on said vehicle when said vehicle enters said automatic driving mode. A travel control device according to any one of the above. 22. A travel control device for controlling travel of the vehicle so that the vehicle travels at a slow speed, a travel mode determining means for determining whether the vehicle is in a slow travel mode, and the travel mode. A driving control device comprising: driving force maintaining means for maintaining the driving force of the vehicle at a predetermined driving force when the vehicle is determined to be in the slow running mode by the determining means. 23. Braking control means for performing braking control of the vehicle so that the actual vehicle speed of the vehicle does not exceed a predetermined set speed when the vehicle is driven by the predetermined driving force. The travel control device according to claim 22, characterized in that: 24. The braking control means predicts a future actual vehicle speed based on a change in the actual vehicle speed of the vehicle, and controls the braking of the vehicle so that the future actual vehicle speed does not exceed the predetermined set speed. The travel control device according to claim 23, wherein: