JP6629775B2 - Vehicle control device - Google Patents

Description

  The present invention relates to a vehicle control device, and particularly when a predetermined condition is satisfied during running of a vehicle (for example, when the accelerator is not depressed for a predetermined time or more), the engine speed is reduced to a predetermined speed and power transmission from the engine to wheels is cut off. The present invention also relates to a vehicle control device that controls a speed drop to cause the vehicle to coast.

  2. Description of the Related Art In recent years, in order to reduce fuel consumption, an engine automatic stop / start system that automatically stops an engine when a vehicle stops and restarts the engine when the vehicle starts moving has become widespread. Further, Patent Literature 1 proposes a technique for further reducing fuel consumption by performing coasting while the vehicle is running in a state in which power transmission between the engine and the wheels is cut off when predetermined conditions are satisfied while the vehicle is running. I have.

  Further, Patent Literature 2 proposes a technique for further reducing fuel consumption by reducing the engine speed during coasting to an idle speed.

JP-A-2004-251279 JP 2011-163535 A

  In the technique of Patent Document 2, when the driver depresses an accelerator pedal to stop coasting, the engine-side rotation speed and the wheel-side rotation speed of the power transmission path are synchronized in order to reduce an engagement shock (pulling shock). Therefore, it is necessary to fasten the power transmission path. Therefore, in the technique of Patent Document 2, since the engine-side rotation speed is increased to the wheel-side rotation speed, there is a problem that it takes time to fasten the power transmission path.

  An object of the present invention has been made in view of such a problem, and when a driver depresses an accelerator pedal during coasting, the operation until the power transmission path between the engine and the wheels is fastened. An object of the present invention is to provide a vehicle control device capable of suppressing a reduction in drivability by shortening a time and suppressing an engagement shock.

  A vehicle control device according to the present invention controls a vehicle including an engine, wheels, and a power transmission path that connects and disconnects transmission of power between the engine and the wheels. The vehicle control device controls the rotational speed of the engine to approach a target rotational speed higher than the idle rotational speed during the inertial traveling in which the power transmission path is interrupted.

  According to the present invention, during coasting, in which the vehicle travels with the power transmission path between the engine and the wheels cut off, the engine-side rotational speed is set between when the driver depresses the accelerator pedal and when the power transmission path is completely engaged. The engagement shock can be suppressed while reducing the time required for raising the pressure. As a result, it is possible to prevent a decrease in drivability.

1 shows an example of an overall configuration diagram of a vehicle equipped with a vehicle control device. 4 shows an example of a sequence of a vehicle control device. 4 shows an example of a flowchart of a process by the vehicle control device. 6 shows an example of characteristics of the vehicle speed and the basic target rotation speed for each speed ratio. 4 shows an example of correction of a basic target rotation speed according to a traveling mode during coasting. An example of an engine speed, a clutch engagement command, and a fuel consumption in each traveling mode is shown. 4 shows an example of correction of a basic target rotation speed according to a vehicle forward distance during coasting. 4 shows an example of correction of a basic target rotation speed according to an uphill angle during coasting. 4 shows an example of a timing chart of coasting in a normal traveling mode. 4 shows an example of a timing chart of coasting in a sporty traveling mode. 4 shows an example of a timing chart of coasting in the eco-drive mode.

  Hereinafter, this embodiment will be described in detail with reference to the drawings.

  FIG. 1 shows an example of an overall configuration diagram of a vehicle equipped with a vehicle control device.

  The vehicle 100 has an engine body 101 (also simply referred to as an internal combustion engine or an engine) as a driving force source. On the output side of the engine 101, a torque converter 102 as a kind of “power transmission path” is provided. A transmission 103 is connected to an output side of the torque converter 102. Further, the engine 101 includes a crankshaft 104 and a crank angle sensor 105 that is an engine speed detecting unit.

  An intake manifold 106 for distributing intake air to each cylinder, a throttle valve 107, an air flow sensor 108, and an air cleaner 109 are attached to the engine 101 as intake system components. The throttle valve 107 is controlled by an engine control unit (hereinafter, referred to as an ECU) 110 as a “vehicle control device”.

  The engine 101 transmits kinetic energy to the crankshaft 104 to generate a rotational driving force. A drive plate (not shown) is provided on the transmission 103 side of the crankshaft 104, and is directly connected to the input side of the torque converter 102. The output side of the torque converter 102 is connected to a forward clutch 111 as a kind of “power transmission path”, and the wheel side of the forward clutch 111 is connected to a transmission 103. The transmission 103 is a transmission main body having a stepped transmission mechanism or a belt-type or disk-type continuously variable transmission mechanism, and is controlled by a transmission control unit (hereinafter, referred to as TCU) 112. Further, the driving force transmitted from the transmission mechanism of the transmission 103 is transmitted to the left and right wheels 114L and 114R via the differential mechanism 113. When coasting, the forward clutch 111 is engaged to transmit the driving force from the torque converter 102 to the transmission mechanism and drive the wheels 114. When the vehicle is not coasting, in order to cut off the reverse driving force from the wheels 114, the forward clutch 111 is released and control is performed so that the reverse driving force is not transmitted to the engine 101 via the torque converter 102. The forward clutch 111 may be installed between the engine 101 and the wheels 114, and may connect between the transmission 103 and the wheels 114.

  An exhaust manifold 115 is attached to the engine 101 as an exhaust system component. The exhaust manifold 115 collects exhaust gas from each cylinder. Further, an EGR hose 116 as an “exhaust gas recirculation (EGR) device” and an EGR valve 117 are attached to the engine 101. The EGR hose 116 is provided between the intake manifold 106 and the exhaust manifold 115. The opening of the EGR valve 117 disposed inside the EGR hose 116 is controlled by the ECU 110.

  The vehicle 100 includes an accelerator pedal sensor 119, a gear shift lever 121, a vehicle speed sensor 122, and a water temperature sensor 123 as state detection components. The accelerator pedal sensor 119 detects the amount of depression of an accelerator pedal 118 that accelerates the vehicle 100. The gear shift lever 121 selects the gear range information 120. Vehicle speed sensor 122 detects the vehicle speed of vehicle 100. Water temperature sensor 123 detects the temperature of cooling water of engine 101.

  The vehicle 100 includes a traveling mode indicator 124, a distance sensor 125, and a climbing angle sensor 126 as external world information acquisition components. The traveling mode indicator 124 is configured so that the driver can select any one of three traveling modes, a sporty traveling mode, a normal traveling mode, and an ecological traveling mode. The distance sensor 125 recognizes a distance from a preceding vehicle. The uphill angle sensor 126 recognizes the inclination angle of the traveling road. Note that the distance sensor 125 may be any component that can recognize the distance to the vehicle in front, and examples thereof include a camera, a millimeter-wave laser sensor, and an infrared sensor. Since the climbing angle sensor 126 may be any component that can recognize the inclination of the traveling road, an inclination sensor and map inclination information of a car navigation system can be used.

  FIG. 2 shows an example of a sequence of the vehicle control device.

  Reference numeral 201 shown in FIG. 2 denotes an ECU configured by blocks 202 to 209. The ECU 201 controls the throttle valve 219, the EGR valve 220, and the forward clutch 221 so that the difference between the engine speed and the target speed is within a predetermined range. Here, the power transmission path includes the torque converter 102 and the forward clutch 111. The engine-side rotation speed of the power transmission path is the rotation speed (engine speed) between the engine 101 and the torque converter 102, and the transmission-side rotation speed of the power transmission path is the forward clutch 111 and the transmission 103. Is the number of rotations between

  FIG. 3 is an example of a flowchart of the processing by the blocks 202 to 209 in FIG. In this flowchart, the processing of steps 301 to 318 is executed only during coasting.

  Return to FIG. The basic target rotation speed calculation unit 202 outputs a basic target rotation speed based on the vehicle speed detected by the vehicle speed sensor 210 and the gear ratio information output by the TCU 211. That is, the transmission-side rotation speed of the torque converter 102 and the forward clutch 111 is the basic target rotation speed. The gear ratio information is a product of the gear ratio controlled by the TCU 211 based on the engine information (engine speed, vehicle speed, throttle opening) and the gear range information 120 of the gear shift lever 121, and the final gear ratio of the differential mechanism 113. . The processing in the basic target rotation speed calculation unit 202 is steps 301 and 302 in FIG.

In step 301 shown in FIG. 3, the vehicle speed and the gear ratio information are read. Then, in step 302, a basic target rotation speed is calculated based on the vehicle speed and the gear ratio information. The basic target rotation speed is set, for example, as in Expression (1).

Basic target rotation speed [r / min] = vehicle speed [km / h] ÷ 60 [min / h] × (speed ratio information) ÷ (tire outer circumference [km]) (1)

  FIG. 4 shows an example of the vehicle speed and the speed ratio characteristics used in step 302.

  Lines 401 to 404 in FIG. 4 show characteristics of the vehicle speed and the basic target speed at different speed ratios. Line 401 has the smallest gear ratio (fourth gear), line 402 has the second smallest gear ratio (third gear), line 403 has the third smallest gear ratio (second gear), and line 404 has the smallest gear ratio (second gear). The gear ratio is the largest gear ratio (first speed). Therefore, if the speed ratio is large, the basic target speed is low, and if the speed ratio is small, the basic target speed is high. Further, the higher the vehicle speed, the higher the basic target rotation speed.

  Return to FIG. Here, the ECU 110 of the present embodiment includes a vehicle speed sensor 122 that detects the vehicle speed of the vehicle 100, and a speed ratio detection unit (not shown) that detects the speed ratio of the transmission 103. Then, during coasting, the target rotation speed is calculated based on the vehicle speed of the vehicle 100 detected by the vehicle speed sensor 122 and the speed ratio of the transmission 103 detected by the speed ratio detection unit.

  Furthermore, in the above configuration, the torque converter 102 and the forward clutch 111 are separately provided with a transmission-side rotation speed detection unit (not shown), and the basic target rotation speed output from the basic target rotation speed calculation unit 202 is: The transmission-side rotation speed information detected by the transmission-side rotation speed detection unit may be used.

  According to the above configuration, for example, even when the vehicle speed or the gear ratio cannot be detected due to disconnection, the basic target rotation speed can be detected.

  Returning to FIG. The target rotation speed calculation unit 204 includes a preset target idle rotation speed, a basic target rotation speed calculated by the basic target rotation speed calculation unit 202, and a basic target rotation speed correction calculated by the basic target rotation speed correction amount calculation unit 203. The target rotation speed is output based on the amount. The process in the target rotation speed calculating unit 204 is Step 310 to Step 313 in FIG.

As shown in FIG. 3, in step 310, the target rotation speed is calculated based on the basic target rotation speed and the basic target rotation speed correction amount (a, b). The target rotation speed is set, for example, as in Expression (2).

Target rotation speed = a × basic target rotation speed + b (2)

Here, a and b are basic target rotation speed correction amounts calculated by a basic target rotation speed correction amount calculation unit 203 described later.

  In step 311, the target idle speed is read. In step 312, it is determined whether the target rotation speed is equal to or higher than the target idle rotation speed. If the determination result of step 312 is true (S312: YES), the process proceeds to step 314 described below. If the determination result in step 312 is false (S312: NO), in step 313, the target rotation speed is set to the target idle rotation speed.

  Here, as shown in FIG. 1, the ECU 110 of the present embodiment controls the engine speed only when the target speed is higher than the idle speed during coasting.

  As a result, the engine 101 becomes lower than the idle speed, and there is no danger of causing the engine stall. Once the engine 101 stops, a large amount of fuel is consumed at the time of restart, which leads to deterioration of fuel efficiency. Therefore, in the ECU 110 of the present embodiment, it is possible to prevent a reduction in fuel consumption due to the engine stall. Further, the ECU 110 of the present embodiment brings the engine speed closer to the target speed higher than the idling speed during the coasting, so that the torque converter 102 and the torque converter 102 are smaller than the conventional example in which the engine speed is reduced to the idling speed. It is possible to shorten the time until the forward clutch 111 is engaged.

Returning to FIG. The basic target rotation speed correction amount calculation unit 203 outputs a basic target rotation speed correction amount based on external world information detected by the traveling mode indicator 215, the distance sensor 216, and the uphill angle sensor 217. The processing in the basic target rotation speed correction amount calculation unit 203 is steps 308 and 309 in FIG. In step 308, external world information is read. Then, in step 309, a basic target rotation speed correction amount is calculated based on the external world information. The basic target rotation speed correction amount is set, for example, as in Expression (3).

Basic target rotation speed correction amount = (a, b) (outside world information) (3)

Here, a is a rotational speed correction magnification, b is an offset rotational speed, and a and b are set based on external world information. When the travel mode indicator 215 is used as external information, a = 1 is set, and b is corrected as shown in FIG.

  FIG. 5 is an example of the basic target rotation speed correction amount between the respective driving modes when the driving mode is used as the external information during the coasting.

  When the driver operates the traveling mode indicator 215, the driving mode is divided into three types: a normal traveling mode, a sporty traveling mode in which the time until the forward clutch 221 is engaged, and an eco-driving mode in which the fuel efficiency is emphasized. It is configured to be configurable. Then, an offset rotation speed b corresponding to each traveling mode is output. In the normal traveling mode, b = 0 is output. In the sporty running mode, b = 100 is set as a correction value that makes the rotation speed higher than the basic target rotation speed. In the eco-drive mode, b = −100 is set as a correction value that becomes a rotation speed lower than the basic target rotation speed.

  FIG. 6 is an example of the engine speed, the clutch engagement command, and the fuel consumption in each of the traveling modes.

  Here, the effect in each traveling mode will be described with reference to FIG. The time 601 is the time when the coasting is started, and the time 602 is the time when the driver depresses the accelerator pedal 118 by a predetermined value or more to generate an acceleration request. Time 603 is the end time of the coasting in the sporty traveling mode, time 604 is the end time of the coasting in the normal traveling mode, and time 605 is the end time of the coasting in the ecological traveling mode. In times 603 to 605, the clutch changes from OFF to ON at the same time as the end of coasting. Comparing the time from the time 602 to the end of the inertial running of each running mode, the sporty mode ends first. On the other hand, when the fuel consumption of each driving mode is compared, the eco driving mode has the lowest fuel consumption.

  Therefore, as shown in FIG. 5, in the sporty traveling mode in which the correction value is set so that the target rotational speed becomes higher (that is, the engine rotational speed becomes higher), the time from the depression of the accelerator pedal 118 to the end of the inertial traveling is reduced. It can be shorter. Further, as shown in FIG. 5, in the eco-drive mode in which the correction value is set so that the target speed decreases (that is, the engine speed decreases), the fuel consumption from the depression of the accelerator pedal 118 to the end of the inertial travel. Can be further reduced. Furthermore, by performing the EGR even in the sporty driving mode, it is possible to improve fuel efficiency.

  FIG. 7 is an example of the basic target rotational speed correction amount when the preceding vehicle distance is used as the external information during coasting.

  Further, in the equation (3), when a distance sensor is used as the external world information, b = 0 and a is corrected as shown in FIG. The forward vehicle distance is detected by the distance sensor 216. Note that the forward vehicle distance may be a combination of detection values from a plurality of sensors and an estimated value without depending on a predetermined sensor. In FIG. 7, the distance for determining that the vehicle 100 is too close to the preceding vehicle is set to 100 m, and when the preceding vehicle distance is shorter than 100 m, the rotational speed correction magnification a is set to be smaller as the vehicle approaches the preceding vehicle. .

  According to the above configuration, when the distance from the vehicle ahead is extremely short, it is assumed that the driver's intention to accelerate is small, and the rotational speed correction magnification a is set small. As described in FIG. 6, the fuel consumption decreases as the target rotation speed decreases, and therefore, according to the present embodiment, the fuel consumption can be reduced. Further, when the vehicle 100 is too close to the preceding vehicle, the time from when the accelerator pedal 118 is erroneously depressed to when the vehicle 100 accelerates becomes longer, and the effect of increasing the grace period for the driver to notice an error may be obtained. It becomes possible.

  Further, in the above configuration, when the distance of the front vehicle is longer than the distance 100 m for determining that the vehicle 100 is too close to the front vehicle, the rotation speed correction magnification a is set to a large value until the predetermined distance farther than 100 m. You may.

  According to the above configuration, when the distance from the preceding vehicle is widened, the vehicle 100 can quickly end the coasting, so that control that facilitates acceleration and following can be performed.

  FIG. 8 is an example of the basic target rotation speed correction amount when the uphill angle is used as the external information during coasting.

  Further, in the equation (3), when the uphill angle is used as the external world information, b = 0 and a is corrected as shown in FIG. The uphill angle is detected by the uphill angle sensor 217. As shown in FIG. 8, when traveling on an uphill, the rotation speed correction magnification a is set to be large, and when traveling on a downhill, the rotation speed correction magnification a is set to be small.

  According to the above configuration, during coasting, when the vehicle 100 travels on an uphill, the rotation speed correction magnification a is set large, and when the vehicle 100 travels on a downhill, the rotation speed correction magnification a Set smaller. Thereby, when traveling on an uphill where the possibility of the driver's intention to accelerate is high, the time until the torque converter 102 and the forward clutch 111 are engaged can be further reduced, and the vehicle speed is less likely to decrease. When traveling uphill, fuel efficiency can be improved.

  Further, in Expression (3), when a plurality of traveling modes, a distance in front of the vehicle, and a climbing angle are used as the outside world information, a is a multiplied value of a plurality of outside world information setting values, and b is a plurality of outside world information setting values. The sum of the values is output.

  Further, in the equation (3), if no external information is used, a = 1 and b = 0 are output.

  Here, the vehicle 100 of the present embodiment includes an external world recognition unit that recognizes external world information, and the ECU 201 acquires the external world information detected by the external world recognition unit, and sets a target based on the acquired external world information during coasting. Correct the rotation speed.

  This makes it possible to flexibly correct the target rotation speed during coasting according to the external world information.

  Returning to FIG. In the target rotation speed feedback unit 205, based on a predetermined threshold value set in the ECU 110 in advance, the target rotation speed calculated by the target rotation speed calculation unit 204, and the engine rotation speed detected by the crank angle sensor 214, the target during coasting is set. Outputs throttle opening. The throttle opening switching unit 206 includes a target throttle opening during coasting output from the target rotation speed feedback unit 205, an accelerator pedal depression amount detected by the accelerator pedal sensor 218, and a clutch output by a clutch engagement determination unit 207 described later. The target throttle opening is output based on the engagement command. Then, the opening of the throttle valve 219 is controlled based on the target throttle opening output by the throttle opening switching unit 206. The processes in the target rotation speed feedback unit 205 and the throttle opening degree switching unit 206 are steps 314 to 316.

Returning to FIG. In step 314, a predetermined threshold is read. In step 315, the target throttle opening during coasting is calculated based on the predetermined threshold value, the target rotation speed, and the engine rotation speed. The target throttle opening during coasting is set, for example, as in equation (4).


Here, Trs1 is a target throttle opening during coasting, e is an engine speed-target speed, Kp1 is a proportional gain, Ki1 is an integral gain, and Kd1 is a differential gain. Kp1, Ki1, and Kd1 are controlled such that the target rotation speed is quickly set within a predetermined range.

Predetermined threshold lower limit value <e <predetermined threshold upper limit value

The value is set so that

  Further, α is a predetermined gain, and α is set in advance based on characteristics of the throttle opening of the engine 101 and the engine speed. However, if target rotation speed> (basic target rotation speed−median of predetermined range), there is a possibility that an engagement shock may occur when the clutch is engaged. Therefore, target rotation speed = (basic target rotation speed−center of predetermined range). Value). Since the process of step 315 is executed when the clutch engagement command is OFF, that is, when the coasting is continued, the target throttle opening is set to the target throttle opening during coasting.

In step 316, a target throttle opening is calculated based on the accelerator pedal depression amount. In this case, the clutch engagement command is ON, that is, the coasting is ended. The target throttle opening when ending coasting is set, for example, as in equation (5).

Target throttle opening = accelerator pedal depression amount (5)

  Here, the vehicle control device of the present embodiment includes an engine 101, wheels 114, a torque converter 102 and a forward clutch 111 for connecting and disconnecting power transmission between the engine 101 and the wheels 114. The ECU 110 according to the present embodiment determines that the difference between the engine speed and the target speed during coasting running when the power transmission between the engine 101 and the wheels 114 is cut off by the torque converter 102 and the forward clutch 111. The engine speed is controlled to be within a predetermined range.

  Accordingly, when the driver depresses the accelerator pedal 118 during coasting, the time required for the target rotation speed based on the engine rotation speed and the wheel-side rotation speed to fall within a predetermined range can be reduced, Drivability can be improved.

  Further, in the above configuration, the driving mode may be automatically switched according to the driving condition without using the driving mode indicator 124.

  According to the above configuration, for example, in a vehicle that runs automatically by the ECU 110, the ECU 110 automatically switches the running mode, so that the vehicle can run according to the running scene even during coasting.

  Further, in FIG. 5, the number of traveling modes does not need to be three, and a desired number of traveling modes may be set according to the granularity to be set.

  According to the above configuration, when many traveling modes are set, a more detailed traveling mode can be selected.

  Returning to FIG. The clutch engagement determination unit 207 determines the basic target rotation speed output by the target rotation speed calculation unit 202, the engine rotation speed detected by the crank angle sensor 214, and the accelerator pedal depression amount detected by the accelerator pedal sensor 218. Outputs a clutch engagement command. Then, the forward clutch 221 is controlled based on the clutch engagement command output by the clutch engagement determination unit 207. The processing in the clutch engagement determination unit 207 is Steps 303 to 307.

In step 303 shown in FIG. 3, the engine speed and the accelerator pedal depression amount are read. In step 304, it is determined whether or not the accelerator pedal depression amount exceeds a predetermined value after coasting. When the determination result of step 304 is false (S304: NO), the process proceeds to step 308. If the determination result of step 304 is true (S304: YES), control is performed in step 305 so that the difference between the engine speed and the basic target speed is less than a predetermined value. For example, the engine speed is controlled as in equation (7).


Here, Ers2 is the target throttle opening, e is the engine speed minus the basic target speed, Kp2 is a proportional gain, Ki2 is an integral gain, and Kd2 is a differential gain. Kp2, Ki2, and Kd2 are set to values such that the difference between the engine speed and the basic target speed quickly falls below a predetermined value. Α is a predetermined gain, and α is set in advance based on characteristics of the throttle opening of the engine 101 and the engine speed.

  In step 306, it is determined whether the state in which the difference between the engine speed and the basic target speed has become less than a predetermined value has continued for less than a predetermined time. If the determination result of step 306 is true (S306: YES), the process proceeds to step 317. If the determination result of step 306 is false (S306: NO), the process proceeds to step 307, and the clutch engagement command is turned on. As a result, the forward clutch 221 is engaged, and the coasting is terminated.

  Here, the vehicle 100 of the present embodiment includes an accelerator pedal sensor 119 that detects a request for acceleration of the vehicle 100. If the ECU 201 detects an acceleration request during coasting, the ECU 201 engages the torque converter 102 and the forward clutch 111 that have been disconnected.

  Thus, the coasting can be ended by promptly reflecting the driver's intention to accelerate during the coasting.

  Further, in the above configuration, when the vehicle 100 generates the acceleration request signal according to the driving situation, the clutch engagement determination unit 207 may determine the acceleration request based on a plurality of pieces of information.

  In the above-described configuration, during coasting with the automatic driving device, control may be performed in combination with an acceleration request according to a driving situation, in addition to an acceleration request by a driver depressing an accelerator pedal. Thereby, it is possible to cancel the coasting and to accelerate and start the vehicle 100 due to factors other than the driver.

The target EGR calculation section 208 outputs a target EGR amount based on the intake air amount detected by the air flow sensor 212, the water temperature detected by the water temperature sensor 213, and the engine speed detected by the crank angle sensor 214. I do. The EGR switching unit 209 performs EGR both when the clutch is engaged and when the clutch is released. Then, EGR valve 220 is controlled such that the target EGR amount output by EGR switching section 209 is attained. The processing in the EGR switching unit 208 is steps 317 and 318. In steps 317 and 318, the target EGR amount is controlled based on the intake air amount, the water temperature, and the engine speed. The target EGR amount is calculated by, for example, Expression (6).

Target EGR amount = β (intake air amount, water temperature, engine speed) (6)

Here, β is a characteristic map adapted to the vehicle 100 in advance, and is set by examining in advance a predetermined intake air amount, a water temperature, and an optimal EGR amount for each engine speed.

  Here, the vehicle 100 of the present embodiment includes an EGR hose 116 and an EGR valve 117 that return exhaust gas to intake air. Then, the ECU 201 performs exhaust gas recirculation during coasting.

  Thus, fuel economy can be reduced during coasting. Further, since the target rotational speed is maintained higher than the idle rotational speed, the effect of reducing fuel consumption by EGR increases.

  Hereinafter, a timing chart of the present embodiment will be described with reference to FIGS.

  FIG. 9 is an example of a timing chart when the coasting is canceled in the normal traveling mode in response to the acceleration request.

  A time 901 shown in FIG. 9 is a time during which the vehicle 100 enters the coasting mode because the accelerator pedal 118 is not depressed for a predetermined time while the vehicle 100 is running at a vehicle speed equal to or higher than a predetermined value. The time 902 is a time when a state in which the difference between the engine speed and the target speed is within a predetermined range elapses a predetermined time, as shown by a solid line as an example. The time 903 is a time when the engine speed has decreased to the idle speed as shown by a dotted line as a conventional example. A time 904 is a time during which the driver depresses the accelerator pedal 118 by a predetermined value or more to input an acceleration request. The time 905 is a time when a state in which the difference between the engine speed and the target speed is less than a predetermined value has passed a predetermined time, as shown by a solid line in the example. The time 906 is a time when a state in which the difference between the engine speed and the target speed is less than a predetermined value has passed a predetermined time, as indicated by a dotted line as a conventional example. Note that, in the conventional example, the target rotation speed and the basic target rotation speed correspond to the wheel-side rotation speeds of the torque converter 102 and the forward clutch 111.

  At time 901, the clutch engagement command is turned off, and the forward clutch 111 is disconnected. The vehicle speed gradually decreases after the accelerator pedal 118 is depressed, and the rotational speed of the torque converter 102 and the forward clutch 111 on the wheel side changes depending on the vehicle speed. In the present embodiment, the target rotational speed is the rotational speed on the wheel side of the torque converter 102 and the forward clutch 111 + the median of a predetermined range, and is the idle rotational speed in the conventional example. The engine speed changes so as to follow the target speed. The difference between the engine speed and the target speed is controlled within a predetermined range set in the ECU 110 in advance.

  At time 902, a predetermined time elapses after the difference between the engine speed and the target speed becomes within a predetermined value. At time 903, control is performed so that the engine speed approaches the idle speed. At time 904, the driver depresses the accelerator pedal 118 by a predetermined amount or more to request acceleration, and the target rotation speed becomes the same value as the wheel-side rotation speed of the torque converter 102 and the forward clutch 111. The engine speed follows the target speed.

  At time 905, the state where the difference between the engine speed and the basic target speed has become less than the predetermined value has passed for a predetermined time, the clutch engagement command is turned on, and the coasting ends. Thereafter, the TCU 112 increases the speed ratio in order to obtain a sufficient driving force. On the other hand, in the conventional example, it is necessary to wait until time 906 before the state in which the difference between the engine speed and the basic target speed becomes less than the predetermined value elapses the predetermined time. Therefore, a time loss from time 904 to time 906 has occurred. In this embodiment, it can be seen that the time loss until the clutch engagement command is turned ON can be reduced from time 904 to time 905.

  The following driving modes correspond to modifications of the normal driving mode. Therefore, the description will focus on the differences from the normal driving mode.

  FIG. 10 is an example of a timing chart in the case where coasting is canceled in the sporty traveling mode in response to an acceleration request in ECU 110 according to the present invention.

  A time 1001 shown in FIG. 10 is a time when the vehicle enters the coasting. The time 1002 is a time when a state where the difference between the engine speed and the target speed is within a predetermined range has passed a predetermined time, as shown by a solid line in the embodiment. The time 1003 is a time when the engine speed has decreased to the idle speed as shown by a dotted line as a conventional example. The time 1004 is a time during which the driver depresses the accelerator pedal 118 by a predetermined value or more and an acceleration request is input. The time 1005 is a time when a state in which the difference between the engine speed and the target speed becomes less than a predetermined value has passed a predetermined time, as shown by a solid line in the example. The time 1006 is a time when a state in which the difference between the engine speed and the target speed is less than a predetermined value has passed a predetermined time, as indicated by a dotted line as a conventional example. Note that, in the conventional example, the target rotation speed and the basic target rotation speed correspond to the wheel-side rotation speeds of the torque converter 102 and the forward clutch 111.

  At time 1001, the clutch engagement command is turned off, and the forward clutch 111 is disconnected. At this time, the sporty travel mode is selected as the travel mode, and the basic target rotation speed correction amount b = 100. In the present embodiment, the target rotational speed is the rotational speed on the wheel side of the torque converter 102 and the forward clutch 111 + 100 + the median of a predetermined range, and is the idle rotational speed in the conventional example. The engine speed changes so as to follow the target speed. The difference between the engine speed and the target speed is controlled within a predetermined range set in ECU 110 in advance.

  FIG. 11 is an example of a timing chart in the case where the ECU 110 according to the present invention cancels the coasting in the eco-drive mode in response to the acceleration request.

  A time 1101 shown in FIG. 11 is a time when the vehicle enters the coasting. The time 1102 is a time when a state in which the difference between the engine speed and the target speed is within a predetermined range elapses a predetermined time, as shown in an actual battle as an example. The time 1103 is a time when the engine speed has decreased to the idle speed as indicated by a dotted line as a conventional example. The time 1104 is a time during which the driver depresses the accelerator pedal 118 by a predetermined value or more and an acceleration request is input. The time 1105 is a time when a state in which the difference between the engine speed and the target speed is less than a predetermined value has passed a predetermined time, as shown by a solid line in the example. The time 1106 is a time when a state in which the difference between the engine speed and the target speed is less than a predetermined value has passed a predetermined time as indicated by a dotted line as a conventional example. Note that, in the conventional example, the target rotation speed and the basic target rotation speed correspond to the wheel-side rotation speeds of the torque converter 102 and the forward clutch 111.

  At time 1101, the clutch engagement command is turned off, and the forward clutch 111 is disconnected. At this time, the sporty traveling mode is selected as the traveling mode, and the basic target rotation speed correction amount b = −100. In this embodiment, the target rotational speed is the rotational speed on the wheel side of the torque converter 102 and the forward clutch 111−100 + the median of a predetermined range, and is the idle rotational speed in the conventional example. The engine speed changes so as to follow the target speed. The difference between the engine speed and the target speed is controlled within a predetermined range set in ECU 110 in advance.

  As mentioned above, although one Embodiment of this invention was described in full detail, this invention is not limited to said Embodiment. Each component is not limited to the above configuration unless the characteristic function of the present invention is impaired.

100 vehicle 101 engine 102 torque converter 110 ECU
111: forward clutches 114L, 114R: wheels 116: EGR hose 117: EGR valve 119: accelerator pedal sensor 122: vehicle speed sensor 201: ECU
220 EGR valve 221 Forward clutch

Claims (6)

In a vehicle control device for controlling a vehicle including an engine, wheels, and a power transmission path that connects and disconnects transmission of power between the engine and the wheels,
A vehicle control device that gradually reduces the rotation speed of the engine so as to follow a target rotation speed higher than an idle rotation speed during coasting while the power transmission path is cut off. During the coasting, after a lapse of a predetermined time after the difference between the rotation speed of the engine and the target rotation speed falls within a predetermined value , the rotation speed of the engine is gradually adjusted to follow the idle rotation speed. Reduce,
The vehicle control device according to claim 1. The vehicle includes a transmission having a plurality of speed ratios,
Calculating the target rotational speed based on the vehicle speed and the gear ratio of the vehicle;
The vehicle control device according to claim 1. Correcting the target rotation speed according to the traveling state of the vehicle,
A vehicle control device according to any one of claims 1 to 3. If the acceleration request of the vehicle is detected during the coasting, the power transmission path is fastened.
The vehicle control device according to claim 1. The vehicle includes an exhaust gas recirculation device that recirculates exhaust gas to intake air,
During the coasting, the exhaust gas is recirculated to the intake air by the exhaust gas recirculation device,
The vehicle control device according to claim 1.