WO2018008536A1

WO2018008536A1 - Vehicle control device

Info

Publication number: WO2018008536A1
Application number: PCT/JP2017/024077
Authority: WO
Inventors: 龍稲葉; 飯星　洋一; 岡田　隆
Original assignee: 日立オートモティブシステムズ株式会社
Priority date: 2016-07-08
Filing date: 2017-06-30
Publication date: 2018-01-11
Also published as: JP6838777B2; JP2018002099A

Abstract

If technology for automatically controlling vehicle speed to reach a set vehicle speed or a restriction speed were applied to a vehicle equipped with sailing stop control, long periods of coasting (sailing stop travel) would be implemented so as to reduce fuel consumption, whereby the driver could experience discomfort. The present invention is a vehicle control device that performs tracking control for tracking a preceding vehicle or automatic travel control for repeatedly accelerating and decelerating so as to travel at a set speed, wherein, when performing said tracking control or said automatic travel control so as to reach a first target speed, if an external information recognition unit recognizes from external information that it will be necessary to change the first target speed to a second target speed slower than the first target speed at a prescribed position in front of the vehicle, the vehicle is controlled to continue accelerating or decelerating so as to travel at the first target speed, after which the engine brake is applied so as to reach the second target speed at the prescribed position.

Description

Vehicle control device

The present invention relates to a vehicle control device having a function of automatically stopping a vehicle such as an automobile, particularly an engine while traveling.

Conventionally, in an automatic acceleration / deceleration device that controls a vehicle so that the speed of the host vehicle matches the set vehicle speed, the speed limit of the road is acquired, and when the acquired speed limit changes, the set vehicle speed is changed to the speed limit. Alternatively, a technique has been proposed that allows the driver to select whether to maintain the set vehicle speed as it is (see, for example, Patent Document 1).
In addition, the vehicle stops when the vehicle is turned on, and the engine is automatically stopped when a predetermined engine stop condition is satisfied, so as to save fuel, reduce exhaust emission, or reduce noise. A vehicle constructed in this way has been proposed and already put into practical use. Moreover, even when the vehicle is not stopped as an engine stop condition, a vehicle equipped with a sailing stop control that further reduces the fuel consumption by automatically stopping the engine during coasting has been proposed (for example, (See Patent Document 2).

JP 2008-265706 A JP 2010-164143 A

However, if a technology that automatically controls the vehicle speed to the set vehicle speed or the limit speed is applied to a vehicle equipped with sailing stop control, a long inertia traveling (sailing stop traveling) is performed in order to reduce fuel consumption. Therefore, there is a possibility that the driver may feel uncomfortable.

The present invention provides a vehicle control apparatus that performs a follow-up control that follows a preceding vehicle or an automatic travel control that repeats acceleration and deceleration so as to travel at a set speed. When the automatic travel control is being performed, and the external information from the external information recognition unit is changed from the first target speed to a second target speed smaller than the first target speed at a predetermined point ahead of the host vehicle. When recognizing that it is necessary, after accelerating and decelerating so as to run at the first target speed, the engine is braked so that the vehicle is brought to the second target speed at the predetermined point. To control to control.

According to the present invention, it is possible to suppress the fuel consumption and the deterioration of the driving performance associated with the automatic acceleration / deceleration traveling. Other configurations, operations, and effects of the present invention will be described in detail in the following examples.

FIG. 1 is a block diagram showing a configuration of a traveling drive system of a sailing stop vehicle according to the present invention. FIG. 2 is a block diagram illustrating a configuration of the vehicle control device. FIG. 3 is a flowchart showing the control contents of automatic acceleration / deceleration determination control executed by the vehicle control device. FIG. 4 is a flowchart showing the control content of the target speed change control calculation unit to be executed by the vehicle control device. FIG. 5 is a time chart for explaining the effects of the present embodiment. FIG. 6 is a flowchart showing the control content of the target speed change control calculation unit to be executed by the vehicle control device. FIG. 7 is a graph showing the relationship between the first target speed and the second target speed for determining whether sailing stop deceleration is possible. FIG. 8 is a time chart for explaining the operational effects of the present embodiment. FIG. 9 is a flowchart showing the control contents of the automatic acceleration / deceleration determination executed by the vehicle control device. FIG. 10 is a flowchart showing the control content of the target speed change control calculation unit to be executed by the vehicle control device. FIG. 11 is a time chart for explaining the operational effects of the present embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a diagram showing a configuration of a vehicle including a vehicle control device according to the first embodiment of the present invention. An engine 101 is mounted on the vehicle 100, and driving force generated by the engine 101 is transmitted to a driving wheel 108 connected via a differential mechanism 107 via a power transmission mechanism 103 and a transmission 102. The vehicle 100 is caused to travel.

The transmission 102 may be a continuously variable transmission combining a belt or chain and a pulley, or a stepped transmission combining a torque converter and a planetary gear mechanism. Moreover, the transmission which combined the continuously variable transmission and the stepped transmission may be sufficient.

In addition, a power transmission mechanism 103 that can control the power transmission amount between the engine 101 and the transmission 102 is provided, and by adjusting the power transmission amount of the engine 101 and the drive wheels 108 by the power transmission mechanism 103, When the fuel supply to the engine 101 is stopped (fuel cut) during traveling, the engine can be stopped. Here, as the power transmission mechanism 103, a torque converter, a dry or wet clutch, or a planetary gear mechanism may be used. A method using a lock-up clutch in the torque converter is also conceivable.

Further, a rotating machine 111 is assembled to the engine 101 as an engine driving device. The rotating machine 111 is driven by supplying electric power from the battery 109, and the engine 101 is rotated using the driving torque. By performing injection and ignition, combustion can be started and the engine can be started. Here, the rotating machine 111 as the engine driving device is not limited to a starter for start, and may be a motor having both functions of a starter motor and a generator. Moreover, the flywheel etc. which rotate using the rotational energy during engine drive, without requiring the electric power from a battery may be used.

The generator 104 is connected to the rotating shaft of the engine 101 using a belt or a pulley, and generates electricity using the rotation of the engine as a power source. The generated power is used in auxiliary equipment such as power steering and air conditioner in the vehicle. Further, the generated power is charged in the battery 109, so that the power can be supplied to the auxiliary equipment in the vehicle even when the engine 101 is stopped and the generator 104 cannot generate power.

Further, the battery 109 may be an electricity storage device having a performance capable of cranking the engine 101, and may use any of a lead storage battery, a nickel metal hydride battery, a lithium ion battery, an electric double layer capacitor, a lithium ion capacitor, and the like. Further, the battery 109 is provided with a battery remaining amount detection sensor capable of detecting the remaining amount of the battery, and based on the information, the vehicle control device 110 determines that the sailing stop is permitted. Moreover, the power generation amount of the generator 104 is controlled based on the information.

Further, it is connected to the crankshaft of the engine 101 via a drive belt in order to generate a hydraulic pressure mainly used for operating the transmission 102 and the power transmission mechanism 103 in the vehicle 100 and performing lubrication and cooling. A hydraulic oil supply oil pump (not shown) is provided, and hydraulic pressure is continuously supplied while the engine 101 is driven.

In addition, an electric oil pump 114 that can be driven by obtaining electric power from the battery 109 is provided, and when the hydraulic oil supply oil pump 105 determines that the hydraulic pressure is not sufficiently supplied, such as when the engine is stopped. The motor can be driven by the motor driver in the electric oil pump to supply the necessary hydraulic pressure. The electric oil pump 114 includes an oil pump main body, an electric motor that rotates the motor, and a motor driver. However, not only a mechanism that can continuously and variably control the drive output by a motor driver or the like, but also a mechanism that can only perform control to switch the output on and off by a relay or the like.

Even when the engine 101 is in operation, the electric oil pump 114 may be operated in order to compensate for the insufficient supply of cooling oil or lubricating oil by the hydraulic oil supply oil pump. The operation is not limited to the temporary stop of the engine 101.

In addition, a hydraulic control circuit 106 is provided for adjusting and supplying the hydraulic pressure generated by the hydraulic oil supply oil pump and the electric oil pump 114 to the transmission 102 and the power transmission mechanism 103. Control of hydraulic control valves and step motors in each hydraulic circuit is performed in order to realize the calculated gear ratio and clutch state.

In addition, the braking device 105 applies a braking force to the driving wheel 108. As a result, the vehicle 100 generates a braking force between the ground contact surface of the drive wheel 108 and the road surface, and can thereby be braked.
A configuration having a hydraulic brake unit and a brake booster as the braking device 105 is conceivable. The hydraulic brake unit independently controls the wheel cylinder pressure that applies the braking torque to the four wheels according to the brake operation force of the driver or according to the vehicle state. The hydraulic brake unit may be a VDC unit that realizes vehicle behavior control such as vehicle dynamics control and vehicle stability control, which are existing controls, or may be an original hydraulic unit and is not particularly limited. The brake booster is a booster that electrically assists the piston stroke force by boosting the brake pedaling force of the driver with respect to the piston in the master cylinder operated by the brake pedal 113. The master cylinder pressure is generated by the force boosted by the brake booster and is output to the hydraulic brake unit. In addition, it is not restricted to the structure which assists electrically, A negative pressure booster using the negative pressure of an engine may be sufficient, and it does not specifically limit.

In addition, a handle 117 is attached for the drive to operate the vehicle.

Further, the vehicle control device 110 controls the engine 101 and the braking device 110 to output the driving force and braking force of the vehicle required for traveling by reading the operation amounts of the accelerator pedal 112 and the brake pedal 113 of the driver. To do. However, as an alternative to the accelerator pedal 112 and the brake pedal 113, when traveling by cruise control control that keeps the vehicle speed constant or adaptive cruise control control that automatically follows a vehicle traveling in front of the host vehicle In addition, in an autonomous driving vehicle or the like in which the vehicle can travel without requiring a driver's operation, a control device that calculates driving force and braking force necessary for traveling from the surrounding information of the vehicle may be used. For this purpose, a changeover switch 115 is attached to the handle 117 for the purpose of switching the driving mode by the driver. However, the mounting location is not limited to this, and it is sufficient that the mounting location is a location where the driver can operate.

The vehicle control device 110 is a device that integrally controls the engine 101, the transmission 102 using the hydraulic control circuit 106, or the power transmission mechanism 103. As shown in FIG. And an interface for communicating with other controllers and sensors.

The main sensors are an engine speed sensor 203 for measuring the engine speed, a wheel speed sensor 204 for estimating the speed of the vehicle 101, and a transmission speed for measuring the speed at each location in the transmission. A sensor, a hydraulic sensor 206 for detecting the state of the hydraulic pressure in the hydraulic control circuit, the transmission, and the power transmission mechanism, an accelerator pedal operation amount sensor 207 for measuring the driver's accelerator operation amount, a driver brake A brake pedal operation amount sensor 208 for measuring the operation amount, an external information acquisition sensor 209 for acquiring external environment information of the vehicle, and the like.

As the external information acquisition sensor 209, a GPS antenna capable of acquiring GPS information, a laser, a radar, a monocular camera, a stereo camera, etc. in front of the vehicle can be considered. Further, it may be an inter-vehicle or road-to-vehicle communication antenna for exchanging information with a vehicle running around or around the road.

Further, the CPU 201 performs calculations necessary for vehicle control, such as an engine control calculation unit, a brake control calculation unit, a hydraulic control calculation unit, and a sailing stop control calculation unit. These perform calculations based on signals obtained from various sensors and information stored in the storage device 203. The storage device 202 stores information such as ignition timing, fuel injection amount, target gear ratio map, and the like.

Next, FIG. 3 shows an automatic acceleration / deceleration determination control calculation unit in which the driver automatically performs acceleration / deceleration running without being operated by the accelerator pedal and the brake pedal, which is implemented in the vehicle control device 110 of the present embodiment. This will be described with reference to the flowchart shown. Specifically, the vehicle control device 110 includes a control unit (CPU 201) that performs engine control, and the control unit (CPU 201) performs a sailing stop start control calculation to perform control. In the present embodiment, the sailing stop indicates that the rotational operation of the engine is stopped in a situation where the vehicle is not stopped.

In step S100, the control unit (CPU 201) of the vehicle control device 110 determines that the vehicle is in the automatic acceleration / deceleration mode. For this reason, it is determined that the vehicle speed is greater than or equal to a predetermined value, the brake pedal is not depressed, the amount of hydraulic pressure supplied to the hydraulic control circuit 106 is greater than or equal to a predetermined value, and the electric oil pump 114 is abnormally determined. It is determined whether all the predetermined automatic acceleration / deceleration mode conditions such as the battery arithmetic amount of the battery 109 being not less than a predetermined value are satisfied. When it is determined that the condition that the automatic acceleration / deceleration mode is ON is satisfied, the process proceeds to step S101. When it is determined that the condition is not satisfied, the process proceeds to step S103. The above automatic acceleration / deceleration mode condition is merely an example, and the present invention is not limited to this, and some conditions may be set as the automatic acceleration / deceleration mode condition.

In step S101, the control unit (CPU 201) of the vehicle control device 110 performs a target speed reduction determination. In the target speed reduction determination, it is determined that the target speed at the point where the host vehicle obtained by the outside world information acquisition sensor 209 will travel in the future is lower than the target speed at the current time. For example, when a front recognition camera is mounted on the vehicle as the external information acquisition sensor 209, it is determined that the target speed is reduced from information on a speed limit sign positioned in front of the host vehicle. In addition, since a laser radar is mounted, a decrease in the target speed can be determined even when curve information of the traveling lane in front of the vehicle is detected.

In addition, GPS location information and map information recorded in the on-board ROM, traffic information such as the occurrence of traffic jams stored in a server or the like that exists outside the vehicle by the communication device, presence of speed limit signs and signals, etc. Based on the above, a decrease in the target speed can be determined.

The driver decelerates in front of the host vehicle based on forward information obtained from the camera, position information obtained by GPS, environmental information obtained from the illuminance sensor and temperature sensor, and past driver operation information recorded in the on-board ROM. Even if it is predicted that the user is expecting, a decrease in the target speed can be determined.

If it is determined that the target speed is decreasing, the process proceeds to step S102. If it is determined that the target speed is not established, the process proceeds to step S103.

In step S102, the control unit (CPU 201) of the vehicle control device 110 performs a target speed change control calculation.

In step S103, the control unit (CPU 201) of the vehicle control device 110 performs an automatic acceleration / deceleration running control calculation.

FIG. 4 is a flowchart showing the target speed change control calculation unit.

In step S201, the control unit (CPU 201) of the vehicle control device 110 performs an automatic acceleration / deceleration mode running calculation.

In step S202, the control unit (CPU 201) of the vehicle control device 110 determines whether a deceleration start condition is satisfied.

Here, the running resistance R1 [N] predicted to be generated due to the road condition in front of the vehicle and the surrounding environment of the vehicle, the deceleration force R2 [N] of the vehicle generated by transmitting the engine friction torque and the power generation torque to the wheels, The vehicle weight M including the occupant, the first vehicle speed V1 [m / s], the second target speed V2 [m / s], and the deceleration when decelerated by the engine brake is a [m / s ^ 2]. Based on these values, the inertial running distance L [m] of the vehicle is estimated using equations (1) and (2).

a = R1 + R2 / M (1)
L = (V1 ^ 2-V2 ^ 2) / 2a (2)
It is determined that the deceleration start condition is satisfied when the inertial travel distance L obtained in this manner and the distance L2 from the current vehicle position to the target speed change point substantially coincide.

If it is determined that the deceleration start condition is satisfied, the process proceeds to step S203. If it is determined that the deceleration start condition is not satisfied, the process proceeds to step S201.

In step S203, the control unit (CPU 201) of the vehicle control device 110 performs an engine brake deceleration process. In the engine brake deceleration process, first, the power transmission mechanism 103 is in a state where the transmission and the engine are in a transmission state. Then, the injector is controlled so that the fuel injection amount injected into the engine is zero. As a result, the combined torque of the engine friction torque and the power generation torque generated by the generator connected to the engine 101 is applied to the driving wheel 108 via the power transmission mechanism 103, the transmission 102, and the differential mechanism 107. give. As a result, the vehicle decelerates toward the second target speed while the vehicle generates power with the generator. In addition, fuel consumption can be reduced because the fuel can be cut without performing fuel injection to the engine.

In step S204, the control unit (CPU 201) of the vehicle control device 110 determines whether an engine brake end condition is satisfied. In the engine brake end condition determination, the condition is established when the vehicle speed substantially coincides with the second target speed. Alternatively, the host vehicle speed may be substantially equal to a value obtained by subtracting a predetermined speed from the second target speed. As a result, when returning to the automatic acceleration / deceleration mode, the acceleration is started from the acceleration side, and no deceleration step is generated, so that the driver's uncomfortable feeling is reduced. If it is determined that the engine brake end condition is satisfied, the target speed change control calculation is ended. If it is determined that the engine brake end condition is not satisfied, the process proceeds to step S203.

As described above, the vehicle control device 110 according to the present embodiment performs the follow-up control that follows the preceding vehicle, or the automatic travel control that repeats acceleration and deceleration so as to travel at the set speed. Then, the control unit (CPU 201) of the vehicle control device 110 performs tracking control or automatic travel control so as to achieve the first target speed, and is ahead of the host vehicle from the external information of the external information recognition unit. When it is recognized that a change from the first target speed to the second target speed smaller than the first target speed is necessary at the predetermined point, the following control is performed. That is, the control unit (CPU 201) controls the host vehicle so as to achieve the second target speed at the predetermined point by applying the engine brake after continuing acceleration and deceleration so as to travel at the first target speed.

Further, when the host vehicle is decelerated by the automatic travel control, it is desirable that the control unit (CPU 201) shuts off the power transmission between the engine 101 and the drive wheels 108 and causes the host vehicle to travel by inertia. In addition, when applying engine brake, the control unit (CPU 201) desirably operates the engine 101 by transmitting power from the drive wheels 108 to the engine 101 while cutting off fuel supply to the engine 101.

FIG. 5 shows a time chart when the above control is performed. The horizontal axis represents the time axis, and the vertical axis represents the driver's accelerator pedal operation amount, the automatic acceleration / deceleration mode state, the vehicle acceleration / deceleration state, and the vehicle speed.

For example, the control unit (CPU 201) of the vehicle control device 110 shifts to the target speed transition mode when the second target speed falls below the first target speed during traveling in the automatic acceleration / deceleration mode. Here, at the time t11, the mode shifts to the target speed shift mode. Then, acceleration or deceleration control is performed by the automatic acceleration / deceleration mode running calculation. Thereafter, it is determined that the deceleration start condition is satisfied. At time t11, when engine brake deceleration is started from this time, the vehicle speed substantially coincides with the second target speed at a point before the point where the vehicle changes the second target speed (t15 when converted to time). It will be. In this case, the speed cannot be recognized by the driver, which may cause a sense of incongruity, and the average speed of the vehicle also decreases, resulting in an increase in the time until the vehicle reaches the destination. Therefore, it is desirable to continue the automatic acceleration / deceleration running at time t11. When engine brake deceleration is started at time t12, when the vehicle reaches a point where the second target speed changes (time t13), it is determined that the host vehicle speed substantially matches the second target speed. Then, engine brake deceleration control is started. Then, at time t13, when the engine brake end condition establishment determination unit determines that the vehicle speed and the second target speed are substantially the same, the target speed change control calculation ends and the automatic acceleration / deceleration travel control calculation is switched to. Here, regarding the end condition, the end condition may be satisfied when the vehicle speed substantially coincides with a value obtained by subtracting a predetermined value from the second target speed (third target speed).

Also, during engine brake deceleration, the driver is informed that the vehicle has been decelerated by engine brake deceleration due to a change in the target speed in front of the vehicle, or is being implemented. The notification method may be an instrument panel of a driver's seat, a display of a car navigation system, a buzzer, or the like. This has the effect of reducing the driver's uncomfortable feeling with respect to the deceleration change caused by the sailing stop deceleration.

Sailing stop deceleration starts at the time when it is detected that the target speed has been changed, or at the point where the target speed changes when sailing stop deceleration is performed, at the time when the vehicle speed substantially matches the value after the target speed change. A method is also conceivable. In addition, a method is also conceivable in which deceleration is performed using the braking device 105 so that the second target speed is reached at a point immediately before the target speed is changed. On the other hand, according to the present embodiment, it is possible to decelerate toward the target speed after the change with the engine brake, and therefore, the deceleration time becomes shorter as compared with the case of decelerating with the sailing stop. It can be expected that the driver's discomfort is reduced.

Also, the battery life can be extended by preventing the amount of charge from being reduced more than necessary by the power generation of the battery by the generator. Moreover, the frequency of use of the rotating machine 111 can be reduced by decelerating by engine braking instead of sailing stop. Therefore, the use of electric energy can be reduced and the fuel used for combustion at the start can be reduced, and the fuel consumption can be improved. Moreover, since the use frequency of the rotary machine 111 can be reduced, the probability of failure of the rotary machine can be reduced.

FIG. 6 is a diagram showing a target speed change control calculation implemented in the vehicle control apparatus 110 according to the second embodiment of the present invention.

In step S300, the control unit (CPU 201) of the vehicle control device 110 determines whether the sailing stop deceleration determination is established. The conditions for the sailing stop deceleration determination are that the difference between the first target speed and the second target speed is smaller than a predetermined value, the amount of hydraulic pressure supplied to the hydraulic control circuit 113 is less than a predetermined value, and the electric oil pump 106 Is determined to be abnormal, the remaining battery level is below a predetermined value, the driver's deceleration request is above a predetermined value, the driver's acceleration request is above a predetermined value, the brake negative pressure is It is determined whether or not a predetermined sailing stop condition such as a decrease is satisfied. If it is determined that the sailing stop deceleration determination condition is satisfied, the process proceeds to step S301. If it is determined that the sailing stop deceleration determination condition is not satisfied, the process proceeds to step S202.

Referring to the sailing stop deceleration determination map shown in FIG. 7 in order to determine that the sailing stop deceleration determination is established. In this map, the horizontal axis indicates the first target speed, and the vertical axis indicates the second target speed.

That is, in this embodiment, the control unit (CPU 201) of the vehicle control device 110 determines whether the sailing deceleration can be performed or not based on the first target speed and the second target speed of the vehicle.

Specifically, when the second target speed is larger than a predetermined value with respect to the first target speed, it is considered that the vehicle is decelerated toward the second target speed in the sailing stop state. For example, when the change in the target speed is caused by a speed limit sign positioned in front of the vehicle, the deceleration time and the deceleration distance become long if the control is performed so as to decelerate at the sailing stop and substantially match the second target speed. This starts deceleration from a distance far beyond the distance at which the driver can recognize the speed limit sign, which may cause the driver to feel uncomfortable or uncomfortable.

On the other hand, when the difference between the first target speed and the second target speed is smaller than a predetermined value, even if sailing stop deceleration is performed, the deceleration time and distance do not become long. Therefore, the possibility of giving the driver a sense of discomfort or discomfort is reduced. Therefore, in this case, the control unit (CPU 201) of the vehicle control device 110 performs control so that sailing stop deceleration is performed instead of engine brake deceleration.

In step S301, the control unit (CPU 201) of the vehicle control device 110 determines that the sailing stop deceleration start condition is satisfied. Here, the vehicle travel resistance R1 [N] predicted from the road condition in the travel direction of the vehicle and the environment around the vehicle, the vehicle weight M [kg] including the occupant, the current vehicle speed V1 [m / s], and the second target speed. V2 [m / s], acceleration when decelerated by the engine brake is a [m / s ^ 2], and based on these values, the coasting distance L [ m].

a = R1 / M (3)
L = (V1 ^ 2-V2 ^ 2) / 2a (4)
It is determined that the deceleration start condition is satisfied when the estimated coasting distance L obtained in this way and the distance L2 from the current vehicle position to the target speed change point substantially coincide. If it is determined that the deceleration start condition is satisfied, the process proceeds to step S302. If it is determined that the deceleration start condition is not satisfied, the process proceeds to step S201.

In step S302, the control unit (CPU 201) of the vehicle control device 110 performs a sailing stop deceleration process. As the sailing stop deceleration process, first, the power transmission mechanism 103 is in a state where the transmission and the engine are not transmitting power (open state).
Then, the injector is controlled so that the fuel injection amount injected into the engine is zero. As a result, the engine speed gradually becomes zero and the sailing stop deceleration state is established. In this state, the friction torque of the engine and the total torque generated by the generator connected to the engine 101 are not transmitted to the drive wheels 108. As a result, the vehicle is decelerated only by the running resistance, so that the deceleration distance can be extended rather than the engine brake decelerating.

In step S303, the vehicle control device 110 determines whether a sailing stop end condition is satisfied. In the sailing stop end condition determination, the condition is established when the vehicle speed substantially coincides with the second target speed. Alternatively, the host vehicle speed may be substantially equal to a value obtained by subtracting a predetermined speed from the second target speed. In this case, the acceleration starts when returning to the automatic acceleration / deceleration mode. As a result, no deceleration step is generated, and the driver's uncomfortable feeling is reduced. If it is determined that the engine brake end condition is satisfied, the target speed change control calculation is ended. If it is determined that the engine brake end condition is not satisfied, the process proceeds to step S302.

Also, when carrying out sailing stop deceleration, the driver is informed that the vehicle is being decelerated by sailing stop deceleration or is being implemented. Furthermore, it is even better to report the reason why the target speed has changed. For example, there is a speed limit sign in front of the vehicle. The notification method may be an instrument panel of a driver's seat, a display of a car navigation system, a buzzer, an audio speaker, or the like. This has the effect of reducing the driver's uncomfortable feeling with respect to the deceleration change caused by the sailing stop deceleration.

As described above, the control unit (CPU 201) of the present embodiment is performing follow-up control or automatic travel control so as to be the first target speed, and at a predetermined point from the external information of the external information recognition unit. When recognizing that a change from the first target speed to the second target speed is necessary, the vehicle travels at the first target speed when the difference between the first target speed and the second target speed is larger than the set value. After continuing acceleration and deceleration as described above, the host vehicle is controlled so that the second target speed is reached at a predetermined point by applying the engine brake.

Further, when the difference between the first target speed and the second target speed is equal to or less than the set value, the control unit (CPU 201) does not continue acceleration and deceleration so as to travel at the first target speed. It is desirable to control the host vehicle so that the second target speed is reached at a predetermined point by interrupting power transmission with the drive wheel 108 and causing the host vehicle to travel inertially.

Further, when the difference between the first target speed and the second target speed is equal to or smaller than the set value, the control unit (CPU 201) continues acceleration and deceleration so as to travel at the first target speed. Instead, it is desirable to control the host vehicle so that the second target speed is reached at a predetermined point by applying the engine brake.

Also, when the difference in change from the first target speed to the second target speed is greater than or equal to the set value, the control unit (CPU 201) desirably notifies the driver that the engine brake deceleration has started. In addition, when the difference in change from the first target speed to the second target speed is equal to or less than the set value, the control unit (CPU 201) desirably notifies the driver that the sailing stop deceleration has started.

Next, a case where the above-described control in the present embodiment is performed will be described with reference to a time chart shown in FIG.

FIG. 8 shows a time chart when the above control is performed. The horizontal axis represents the time axis, and the vertical axis represents the driver's accelerator pedal operation amount, automatic acceleration / deceleration mode state, vehicle acceleration / deceleration state, and vehicle speed, respectively.

For example, the control unit (CPU 201) of the vehicle control device 110 shifts to the target speed transition mode when the second target speed falls below the first target speed during traveling in the automatic acceleration / deceleration mode. Here, at the time t11, the mode shifts to the target speed shift mode. Then, by referring to the first target speed, the second target speed, and the sailing stop deceleration determination map, it is determined whether the sailing stop deceleration is performed or the sailing stop deceleration is performed. Here, since the difference between the first target speed and the second target speed is smaller than a predetermined value, sailing stop deceleration is selected. Then, it is determined that the sailing stop deceleration start condition is satisfied. When sailing stop deceleration was performed in the same manner as in Example 1, it was determined that the vehicle speed at the time (time t13) when the vehicle reached the change point of the second target speed substantially matches the second target speed. Sailing stop deceleration control is started at time (time t12). Then, at time t13, when the sailing stop end condition establishment determining unit determines that the vehicle speed and the second target speed substantially match, the target speed change control calculation ends, and the automatic acceleration / deceleration travel control calculation is switched to. Here, regarding the end condition, the end condition may be satisfied when the vehicle speed substantially coincides with a value obtained by subtracting a predetermined value from the second target speed (third target speed).

FIG. 9 is a diagram showing a target speed change control calculation implemented in the vehicle control apparatus 110 according to the third embodiment of the present invention.

In step S100, the control unit (CPU 201) of the vehicle control device 110 determines that the vehicle is in the automatic acceleration / deceleration mode. If it is determined that the automatic acceleration / deceleration mode condition is satisfied, the process proceeds to step S101. If it is determined that the automatic acceleration / deceleration mode condition is not satisfied, the process proceeds to step S401.

In step S401, the control unit (CPU 201) of the vehicle control device 110 determines whether the driver has turned on the automatic acceleration / deceleration start changeover switch 115 when not in the automatic acceleration / deceleration mode. If the ON operation has been performed, the process proceeds to step S101. If not, the target speed change control calculation ends.

In step S101, the control unit (CPU 201) of the vehicle control device 110 performs a target speed reduction determination. If the target speed has decreased, the process proceeds to S402, and if not, the target speed change control calculation ends.

In S402, the control unit (CPU 201) of the vehicle control device 110 performs automatic acceleration / deceleration mode transition control.

FIG. 10 is a flowchart showing the automatic acceleration / deceleration mode transition control unit.

In S500, the control unit (CPU 201) of the vehicle control device 110 performs driver requested acceleration estimation. In order to estimate the driver's acceleration / deceleration intention, a method of obtaining from the accelerator opening is conceivable. In addition, a correction method using not only the accelerator opening but also the inter-vehicle distance and relative speed with the preceding vehicle, the road surface condition, the road shape, and the road sign is also conceivable. For example, when the distance to the preceding vehicle or the speed limit sign located in front of the host vehicle is large and the accelerator opening is large, the estimated driver request acceleration is estimated to be a large value.

In S501, the control unit (CPU 201) of the vehicle control device 110 determines that the driver requested acceleration is smaller than the predetermined acceleration. If it is smaller, the process proceeds to S302, and if it is not smaller, the process proceeds to S502. Although it is necessary to identify a value that does not impair drivability using experiments, the predetermined acceleration may be set to zero, which is a boundary value between deceleration and acceleration, for example.

In S502, the control unit (CPU 201) of the vehicle control device 110 performs an acceleration mode process. In the acceleration mode process, the vehicle is accelerated for a predetermined time in accordance with the estimated driver request acceleration of the driver. After a predetermined time has elapsed, the process proceeds to S202, and it is determined whether a deceleration start condition is satisfied. If not established, the acceleration is continued, and if established, the process proceeds to S203.

By performing the automatic acceleration / deceleration mode transition control based on the driver's required acceleration as described above, the driver's uncomfortable feeling when shifting to the automatic acceleration / deceleration mode can be reduced. For example, when the driver operates the automatic acceleration / deceleration mode switch, if the road speed limit recognized by the driver at that time is greater than the current vehicle speed and the accelerator pedal is greater than or equal to a predetermined value, the driver It is thought that the vehicle is expecting an acceleration state. At that time, if sailing deceleration or engine brake deceleration is started, the driver may recall a malfunction of the engine or the like, and may feel uncomfortable or uncomfortable. Therefore, when the driver is expected to be in an accelerated state, the acceleration mode process is performed, thereby reducing the possibility of having such a sense of discomfort or discomfort.

As described above, the host vehicle of the present embodiment includes a switching unit that switches from normal operation to follow-up control or automatic travel control. And the control part (CPU201) of a present Example is in the state in which the driver has stepped on the accelerator pedal 112 of the own vehicle, and when the switching part performs the switching operation to the tracking control or the automatic travel control, and The following control is performed when it is recognized from the external information of the external information recognition unit that a change from the first target speed to the second target speed smaller than the first target speed is necessary at a predetermined point ahead of the host vehicle. . In this case, the control unit (CPU 201) causes the vehicle to travel at the first target speed, and then interrupts power transmission between the engine 101 and the drive wheels 108 to cause the vehicle to travel inertially, or to engine brake. To control the host vehicle so that the second target speed is reached at a predetermined point.

In addition, the control unit (CPU 201) performs the switching control to the tracking control or the automatic travel control by the switching unit while the driver is stepping on the accelerator pedal 112 of the host vehicle, and the external information recognition unit The following control is performed when it is recognized from the external information that a change from the first target speed to the second target speed is necessary at a predetermined point ahead of the host vehicle.
In this case, when the difference between the first target speed and the second target speed is greater than the set value, the control unit (CPU 201) causes the host vehicle to travel at the first target speed, and then the engine 101 and the driving wheels 108. The own vehicle is controlled so as to reach the second target speed at a predetermined point by interrupting the power transmission between the vehicle and running the vehicle with inertia or by applying an engine brake.

FIG. 11 shows a time chart when the required acceleration is not smaller than the predetermined acceleration in the above control. The horizontal axis represents the time axis, and the vertical axis represents the driver's accelerator pedal operation amount, automatic acceleration / deceleration mode state, vehicle acceleration / deceleration state, and vehicle speed, respectively.

At time t11, the driver operates the changeover switch to enter the automatic acceleration / deceleration mode.
In this state, since the driver has operated the accelerator pedal, the driver determines that the required acceleration is not smaller than the predetermined acceleration, and enters an acceleration state. At the time (time t12) when it is determined that the vehicle speed at the time (time t13) when the vehicle reaches the change point of the second target speed when the engine brake is decelerated substantially matches the second target speed. Then, engine brake deceleration control is started.

100 vehicle, 101 engine, 102 transmission, 103 power transmission mechanism, 104 generator, 105 braking device, 106 hydraulic control circuit, 107 differential mechanism, 108 drive wheels, 109 battery, 110 vehicle control device, 111 rotating machine, 112 Accelerator pedal, 113 Brake pedal, 114 Electric hydraulic oil supply pump, 115 Automatic acceleration / deceleration travel switch, 116 Communication device, 117 Vehicle operation handle, 201 CPU, 202 Storage device, 203 Engine speed sensor, 204 Wheel speed sensor, 205 Transmission rotation speed sensor, 206, hydraulic pressure sensor, 207, accelerator pedal operation amount sensor, 208, brake pedal operation amount sensor, 209 external information acquisition sensor

Claims

In a vehicle control device that performs follow-up control that follows a preceding vehicle, or automatic travel control that repeats acceleration and deceleration so as to travel at a set speed,
The follow-up control or the automatic travel control is performed so as to be the first target speed, and the first target speed is determined from the first target speed at a predetermined point ahead of the host vehicle from the external information of the external information recognition unit. When recognizing that it is necessary to change to a second target speed smaller than the one target speed,
A vehicle control apparatus comprising a control unit that controls the host vehicle so that the second target speed is reached at the predetermined point by applying an engine brake after continuing acceleration and deceleration so as to travel at the first target speed .
The vehicle control device according to claim 1,
The control unit is performing the follow-up control or the automatic travel control so as to be the first target speed, and from the first target speed at the predetermined point from the external information of the external information recognition unit. In recognizing that a change to the second target speed is necessary,
When the difference between the first target speed and the second target speed is larger than a set value, acceleration and deceleration are continued so that the vehicle travels at the first target speed, and then the engine brake is applied to apply the predetermined point. The vehicle control apparatus which controls the own vehicle so that it may become said 2nd target speed.
In the vehicle control device according to claim 1 or 2,
The host vehicle includes an engine and drive wheels,
The said control part is a vehicle control apparatus which interrupts | blocks the power transmission between the said engine and the said driving wheel, and drives the said own vehicle by inertia, when decelerating the said own vehicle by the said automatic running control.
In the vehicle control device according to claim 1 or 2,
The host vehicle includes an engine and driving wheels, and the control unit transmits power from the driving wheels to the engine while shutting off fuel supply to the engine when the engine brake is applied. A vehicle control device for operating the engine.
In the vehicle control device according to claim 1 or 2,
When the difference between the first target speed and the second target speed is less than or equal to the set value, the control unit does not continue acceleration and deceleration so that the vehicle travels at the first target speed. A vehicle control device that controls the host vehicle so that the second target speed is reached at the predetermined point by interrupting power transmission between the vehicle and the drive wheels and causing the host vehicle to travel by inertia.
In the vehicle control device according to claim 1 or 2,
When the difference between the first target speed and the second target speed is equal to or less than a set value that is smaller than the set value, the control unit continues acceleration and deceleration so as to travel at the first target speed. And a vehicle control device for controlling the host vehicle so that the second target speed is reached at the predetermined point by applying the engine brake.
In a vehicle control device that performs follow-up control that follows a preceding vehicle, or automatic travel control that repeats acceleration and deceleration so as to travel at a set speed,
The host vehicle includes a switching unit that switches from normal operation to the follow-up control or the automatic travel control,
When the driver is stepping on the accelerator pedal of the host vehicle and the switching unit performs the switching operation to the tracking control or the automatic travel control, and from the external information of the external information recognition unit When recognizing that a change from the first target speed to a second target speed smaller than the first target speed is necessary at a predetermined point ahead,
After traveling the host vehicle at the first target speed, the power transmission between the engine and the drive wheels is interrupted to cause the host vehicle to travel by inertia, or by applying an engine brake, the predetermined point. And a control unit that controls the host vehicle so that the second target speed is reached.
The vehicle control device according to claim 7, wherein
The control unit, when the driver performs the switching operation to the follow-up control or the automatic travel control with the switching unit in a state where the driver is stepping on the accelerator pedal of the host vehicle, and the external information recognition unit When recognizing that a change from the first target speed to the second target speed is necessary at a predetermined point ahead of the host vehicle from the external information of
When the difference between the first target speed and the second target speed is greater than a set value, power is transmitted between the engine and the drive wheels after the host vehicle has traveled at the first target speed. A vehicle control device comprising a control unit that controls the host vehicle so as to achieve the second target speed at the predetermined point by blocking the vehicle and running the host vehicle by inertia or applying an engine brake.
The vehicle control device according to claim 2,
When the difference in change from the first target speed to the second target speed is greater than or equal to a set value, the control unit notifies the driver that the engine brake deceleration has started. .
The vehicle control device according to claim 2,
When the difference in change from the first target speed to the second target speed is equal to or less than a set value, the control unit notifies the driver that the sailing stop deceleration has started. .