JP6705403B2 - Vehicle control device - Google Patents

Description

The present invention relates to a vehicle control device.

In recent years, for the purpose of improving fuel efficiency and the like, a technology has been put into practical use for putting a vehicle in a coasting state by disengaging a clutch device provided between an engine and a transmission when the accelerator is off while the vehicle is traveling (for example, , Patent Document 1). This coasting is a technique that uses the kinetic energy of the vehicle for traveling as it is, and it is possible to improve fuel efficiency by extending the traveling distance of the vehicle.

On the other hand, so-called regenerative traveling is known in which kinetic energy during deceleration of the vehicle is recovered as regenerative energy to improve the energy efficiency of the vehicle. For example, in regenerative power generation that converts kinetic energy into electric energy, rotation of an engine output shaft or the like causes a motor to function as a generator, and electric energy generated by power generation is stored in a battery.

JP, 2016-22772, A

Here, from the viewpoint of further improving fuel economy, it is considered desirable to be able to switch between coasting and regenerative driving, and to use each driving properly. By the way, when shifting from inertia running to regenerative running, it is necessary to connect the clutch in the disengaged state. In this case, in order to reduce vibration and noise when the clutch is connected, it is desirable to connect the clutch in a state where the engine speed is increased, which involves energy consumption. Therefore, depending on the embodiment of the regenerative traveling, it is considered that the energy consumed for increasing the engine rotation speed may be larger than the energy recovered by the regenerative traveling. In such a case, it is not preferable from the viewpoint of improving fuel efficiency.

The present invention has been made in view of the above circumstances, and a main object of the present invention is to provide a vehicle control device that can appropriately switch between coasting and regenerative traveling.

In the first way,
An engine (11) as a travel drive source, a clutch device (17) provided in a power transmission path connected to an output shaft (12) of the engine, and a regenerative device (for recovering kinetic energy of the vehicle via the output shaft ( 13) and a vehicle (10) comprising
In response to the satisfaction of a predetermined coasting execution condition, the clutch device is disengaged to carry out the coasting of the vehicle, and the engine speed is adjusted according to the satisfaction of a predetermined regeneration execution condition during coasting. A travel control unit that performs the transition from the inertial travel to the regenerative travel using the regenerative device by connecting the clutch device,
When the brake operation as the regeneration execution condition is performed during the inertia traveling, the energy consumption consumed by the adjustment of the engine speed is estimated and the regeneration energy recovered by the regeneration traveling is estimated. Department,
Equipped with
The traveling control unit may perform a transition from the inertia traveling to the regenerative traveling based on a comparison between the consumed energy and the regenerative energy.

When shifting from coasting to regenerative running, it is necessary to adjust the engine speed and connect the clutch device, and this engine speed adjustment involves energy consumption. Therefore, from the viewpoint of energy efficiency, it is desirable to shift to regenerative traveling in consideration of energy consumption.

In this respect, in the above configuration, when the brake operation is performed as the predetermined regeneration execution condition during coasting, the energy consumption consumed by the adjustment of the engine rotation speed is estimated and the regeneration recovered by the regeneration running is performed. Estimate energy. Then, based on the comparison between the consumed energy and the regenerative energy, the transition from the inertia traveling to the regenerative traveling is performed. In this case, it is possible to suppress the transition to regenerative traveling, which is disadvantageous from the viewpoint of energy efficiency, for example, by transitioning to regenerative traveling after considering energy consumption. In addition, the frequency of switching from coasting to regenerative traveling can be suppressed, leading to improved drivability. Thereby, coasting and regenerative running can be appropriately switched.

The brake operation as the regeneration execution condition may be a brake pedal operation by a driver or a deceleration determination by a vehicle operation control unit (for example, an automatic operation control unit). Further, when the brake operation is performed during coasting, it is considered that the engine rotation speed is adjusted by driving the rotating machine, and the electrical energy required to drive the rotating machine is estimated as the consumed energy. Good.

The second means includes a determination unit that determines that the regenerative energy estimated by the estimation unit is greater than the consumed energy, and the traveling control unit determines that the regenerated energy is greater than the consumed energy. When it is determined that the coasting is switched to the regenerative traveling, the coasting is maintained when the regenerative energy is determined to be smaller than the consumed energy.

When it is determined that the regenerative energy is larger than the consumed energy, the coasting is switched to the regenerative traveling, so that the energy more than the consumed energy can be recovered by the regenerative traveling. Further, when the regenerative energy is determined to be smaller than the energy consumption, the inertia traveling is maintained, so that the fuel consumption effect by the inertia traveling is obtained and the shift to the regenerative traveling, which is disadvantageous from the viewpoint of energy efficiency, is suppressed. be able to.

In the third means, the estimation unit estimates the energy consumption based on the vehicle speed of the vehicle when the brake operation as the regeneration execution condition is performed during the inertia running.

Energy consumption is energy required to rotate the output shaft of the engine up to the target engine rotation speed, and is considered to be correlated with the vehicle speed. That is, when the vehicle speed is high, the target engine rotation speed becomes high, and the energy consumption also increases accordingly. In consideration of this point, the energy consumption is estimated based on the vehicle speed, so that the energy consumption can be accurately estimated. This makes it possible to properly determine the transition from coasting to regenerative traveling.

In the fourth means, the estimating unit estimates the regenerative energy based on the brake operation amount when a brake operation as the regenerative execution condition is performed during the inertia running.

It is considered that the regenerative energy correlates with the brake operation amount. For example, when the brake operation amount is large, the driver's deceleration request is large, and the regenerative energy is also large. In consideration of this point, since the regenerative energy is estimated based on the brake operation amount, the regenerative energy can be accurately estimated. This makes it possible to properly determine the transition from coasting to regenerative traveling.

In a fifth means, when the brake operation is performed during the inertia traveling, a setting unit that sets a duration of the regenerative traveling is provided, and the estimation unit sets the brake operation amount and the duration. Based on this, the regenerative energy is estimated.

It is considered that the regenerative energy correlates with the duration of regenerative running. For example, the longer the duration of regenerative running, the larger the regenerative energy. In consideration of this point, the duration of regenerative traveling is set when the brake operation is performed during coasting, and the regenerative energy is estimated based on the set duration and the brake operation amount. Energy can be accurately estimated.

In a sixth means, a storage unit that stores the duration when the regenerative traveling is performed is provided, and the setting unit, based on the history of the duration stored by the storage unit, the duration. To set.

When the regenerative traveling is performed, the duration is stored, and the duration is set based on the history of the stored duration, so the duration is set according to the tendency of the regenerative traveling for each vehicle. be able to. This allows the duration to be set appropriately.

In a seventh means, the storage unit stores the continuation time for each of a plurality of determined traveling conditions of the vehicle, and the setting unit, when the brake operation is performed during the inertia traveling, The history is acquired according to the traveling condition of the vehicle, and the duration is set based on the history.

It is considered that the regenerative time of regenerative running affects the operating conditions in each case. For example, the higher the vehicle speed, the longer the regeneration time. In consideration of this point, when the brake operation is performed during the inertia running, the history of the duration time is acquired according to the traveling condition of the vehicle, and the duration time is set based on the history. In this case, by acquiring the history of the duration time according to the traveling condition each time, the duration time can be set in consideration of the condition affecting the regeneration time. As a result, the duration can be set accurately according to the operating conditions at each time.

In an eighth aspect, the regenerative device is a rotating electric machine (13) that performs regenerative power generation for recovering kinetic energy of the vehicle as electric energy, and is based on a state of a storage battery that stores electric power generated by the rotating electric machine. And a correction unit that corrects the regenerative energy estimated by the estimation unit.

In the configuration in which the electric power generated by the regenerative power generation by the rotating electric machine is stored in the storage battery, for example, when the storage battery is close to full charge, it is considered that the energy recovery is limited even if the coasting is switched to the regenerative traveling. Considering this point, the regenerative energy is corrected based on the state of the storage battery. In this case, in addition to the energy balance, by considering the state of storing energy, it is possible to preferably suppress the shift to regenerative traveling, which is disadvantageous from the viewpoint of energy efficiency.

In a ninth means, the regenerative device is a rotary electric machine (13) that performs regenerative power generation for recovering kinetic energy of the vehicle as electric energy, and is estimated by the estimation unit based on a state of the rotary electric machine. A correction unit for correcting the regenerative energy is also provided.

In the configuration in which regenerative power generation is performed by the rotating electric machine, for example, when the temperature inside the rotating electric machine is high, it is considered that the energy recovery is limited even when the coasting is changed to the regenerative traveling. Considering this point, the regenerative energy is corrected based on the state of the rotating electric machine. In this case, in addition to the energy balance, the state of the energy recovery side is taken into consideration, so that the shift to regenerative traveling, which is disadvantageous from the viewpoint of energy efficiency, can be suitably suppressed.

In the tenth means, in the vehicle, it is possible to apply a rotational force to the output shaft by a rotating machine (13), and the traveling control unit, when shifting from the inertia traveling to the regenerative traveling, If the engine speed is lower than a predetermined value, the rotating machine is operated to increase the engine speed, and if the engine speed is higher than the predetermined value, the engine speed is increased by combustion of the engine.

When increasing the engine rotation speed, the combustion efficiency of the engine is low in the low rotation speed range, so it is considered that the driving by the rotating machine is more efficient than the combustion of the engine. On the other hand, the combustion efficiency of the engine is good in the high rotation speed range. Considering this point, when shifting from inertial running to regenerative running, if the engine speed is less than a predetermined value, activate the rotating machine, and if the engine speed is higher than a predetermined value, increase the engine speed by burning the engine. By doing so, the energy consumption at the time of shifting to regenerative traveling can be made as small as possible, and energy efficiency can be improved.

In an eleventh means, the regenerative device is a rotating machine (13) and is applied to a vehicle in which a gear ratio between the output shaft and a rotating shaft (14) of the rotating machine is variable, and in the coasting, A gear shift control unit is provided that changes the gear ratio to a side that suppresses a decrease in the engine rotation speed.

In the above configuration, the gear ratio between the engine output shaft and the rotating shaft of the rotating machine is changed to a side that suppresses a decrease in the engine rotation speed during coasting. In this case, by changing the gear ratio, the inertia of the engine during coasting increases and the period during which the engine output shaft rotates can be extended. As a result, a decrease in the engine rotation speed is less likely to occur after the start of the coasting, and for example, when the coasting immediately shifts to the normal traveling, the rotation of the engine output shaft is secured and the energy consumption accompanying the shift is reduced. be able to.

In the twelfth means, the speed change ratio is a ratio of the rotation speed of the rotation shaft of the rotating machine to the rotation speed of the output shaft, and the speed change control unit is configured to satisfy the predetermined coasting execution condition. The gear ratio is made larger than before, and the gear ratio is made smaller when the coasting is released.

When traveling by combustion of the engine, the rotating machine is rotated, and sliding loss occurs due to the rotation. In consideration of this point, the gear ratio is reduced when the coasting is released. In this case, the rotational speed of the rotating machine with respect to the engine rotational speed after the coasting is released becomes smaller than that during coasting. As a result, in the non-inertia traveling state after canceling the inertial traveling, the sliding loss due to the rotation of the rotating machine can be reduced, and the traveling by the combustion of the engine can be suitably performed.

In the thirteenth means, the speed change ratio is a ratio of the rotation speed of the rotating shaft of the rotating machine to the rotation speed of the output shaft, and the speed change control unit is configured to satisfy the predetermined coasting execution condition. The gear ratio is made larger than before, and the gear ratio is made smaller when the engine rotation speed becomes equal to or higher than a predetermined rotation speed due to the adjustment of the engine rotation speed.

When the engine rotation speed is increased by driving the rotating machine, it is considered that a large torque is not necessary when the engine rotation speed is in a rotation speed range equal to or higher than a predetermined rotation speed. In consideration of this point, in the above configuration, when the engine rotation speed becomes equal to or higher than the predetermined rotation speed due to the adjustment of the engine rotation speed, the gear ratio is reduced, so that the rotating machine is released before the inertia traveling is released. Sliding loss can be reduced, which in turn can reduce energy consumption associated with the transition to non-inertia traveling.

In a fourteenth means, the regenerative device is a rotary electric machine (13) for performing regenerative power generation for recovering kinetic energy of the vehicle as electric energy, and the regenerative power generation by the rotary electric machine is performed at a predetermined output or less. Applied to a vehicle, when the brake operation is performed during the inertia running, a setting unit that sets a duration of the regenerative traveling and a required output that requests the regenerative traveling, and the duration is a predetermined time. Below, and when the required output is greater than or equal to a predetermined value, a permission unit that permits the regenerative power generation at an output greater than the predetermined output.

Regenerative power generation by the rotating electric machine is performed (output is limited) at a predetermined output or lower in consideration of heat and the like associated with the power generation operation. Therefore, for example, even when the brake operation amount is large and the required output for regenerative traveling is large, the regenerative energy may not be sufficiently recovered due to the output limitation.

In this point, in the above configuration, in the case where the braking operation is performed during the inertia running, the duration of the regenerative running is the predetermined time or less, and when the required output is the predetermined or more, the output is larger than the predetermined output. Allowed regenerative power generation. For example, when the duration of regenerative traveling is extremely short and the required output is large, regenerative power generation with an output larger than the predetermined output becomes possible. That is, in this case, if the regenerative power generation time is extremely short, the temperature rise of the rotating electric machine can be suppressed even if the regenerative power generation is performed above the output limit. As a result, it is possible to efficiently recover the regenerative energy corresponding to the required output while suppressing an excessive temperature rise of the rotating electric machine.

The block diagram which shows the outline of a vehicle control system. Explanatory drawing which shows the outline of each running state. The timing chart at the time of shifting to the regenerative running state from the inertia running state. The flowchart which shows a traveling control process. The correlation diagram which shows the relationship between SOC and coefficient (alpha). The flowchart which shows the traveling control process in 2nd Embodiment. The flowchart which shows the estimation process of the regenerative energy in 3rd Embodiment. FIG. 3 is a correlation diagram showing the relationship between vehicle speed, road surface slope, and regeneration duration. The block diagram which shows the outline of the vehicle control system in 4th Embodiment. The flowchart which shows the process procedure of the shift control in 4th Embodiment. The timing chart at the time of coasting in 4th Embodiment. The flowchart which shows the process sequence of the regenerative power generation in 5th Embodiment. FIG. 5 is a correlation diagram showing a relationship among a brake operation amount, a road surface gradient, and a regeneration request output.

(First embodiment)
Hereinafter, embodiments embodying the present invention will be described with reference to the drawings. In this embodiment, in a vehicle equipped with an engine as a drive source, a normal drive mode in which the clutch is in a power transmission state, a coasting mode in which the clutch is in a power disengaged state, and a clutch drive is performed. Regenerative traveling in which the kinetic energy of the vehicle is regenerated in the transmission state is selectively performed.

In the vehicle 10 shown in FIG. 1, an engine 11 is a multi-cylinder internal combustion engine driven by combustion of fuel such as gasoline or light oil, and is provided with a fuel injection valve, an ignition device and the like as is well known. The engine 11 is integrally provided with an ISG 13 as a generator and an electric motor, and a rotating shaft 14 of the ISG 13 is drivingly connected to the engine output shaft 12 by a belt or the like. In this case, the rotation of the engine output shaft 12 causes the rotation shaft 14 of the ISG 13 to rotate, while the rotation of the rotation shaft 14 of the ISG 13 causes the engine output shaft 12 to rotate. That is, the ISG 13 has a power generation function of generating power (regenerative power generation) by rotation of the engine output shaft 12 and a power output function of applying a rotational force to the engine output shaft 12. When the engine is started, the rotation of the ISG 13 gives initial rotation (cranking rotation) to the engine 11.

A vehicle-mounted battery 15 as a storage battery is electrically connected to the ISG 13. In this case, the ISG 13 is driven by being supplied with power from the battery 15, and the battery 15 is charged by the power generated by the ISG 13. The electric power of the battery 15 is used to drive various electric loads mounted on the vehicle.

In addition to the ISG 13, an auxiliary device 16 such as a water pump or a fuel pump is mounted on the vehicle 10 as a driven device driven by the rotation of the engine output shaft 12. In addition, an air conditioner compressor may be included as a driven device. The driven devices include those directly connected to the engine output shaft 12 and those in which the coupling state with the engine output shaft 12 is interrupted by the clutch means, in addition to the one driven and connected to the engine 11 by a belt or the like. ..

A transmission 18 is connected to the engine output shaft 12 via a clutch device 17 having a power transmission function. The clutch device 17 is, for example, a friction clutch, and includes a disc (flywheel etc.) on the engine 11 side connected to the engine output shaft 12 and a disc (clutch disc) on the transmission 18 side connected to the transmission input shaft 21. Etc.) and a set of clutch mechanisms. When both discs contact each other in the clutch device 17, a power transmission state (clutch connection state) in which power is transmitted between the engine 11 and the transmission 18 is established, and the two discs are separated from each other. , The power transmission state between the engine 11 and the transmission 18 is cut off (clutch disengagement state). The clutch device 17 of the present embodiment is configured as an automatic clutch that switches between a clutch engaged state and a clutch disengaged state by an actuator such as a motor. The clutch device 17 may be provided inside the transmission 18.

The transmission 18 is, for example, a continuously variable transmission (CVT) or a multi-stage transmission having a plurality of shift stages. The transmission 18 shifts the power of the engine 11 input from the transmission input shaft 21 according to the gear ratio according to the vehicle speed V and the engine rotation speed, and outputs the power to the transmission output shaft 22.

Wheels 27 are connected to the transmission output shaft 22 via a differential gear 25 and a drive shaft 26 (vehicle drive shaft). Further, the wheels 27 are provided with a brake device 28 that applies a braking force to each wheel 27 by being driven by a hydraulic circuit or the like (not shown). The brake device 28 adjusts the braking force applied to each wheel 27 according to the pressure of a master cylinder (not shown) that transmits the pedal effort of the brake pedal to the hydraulic fluid.

In addition, the present system includes an engine ECU 31 that controls the operating state of the engine 11 and a transmission ECU 32 that controls the clutch device 17 and the transmission 18, as vehicle-mounted control means. Each of the ECUs 31 and 32 is a well-known electronic control device including a microcomputer and the like, and controls the engine 11, the transmission 18, etc. based on the detection results of various sensors provided in the system. Are appropriately implemented. The ECUs 31 and 32 are communicably connected to each other and can share control signals, data signals, and the like with each other. In the present embodiment, the configuration is provided with two ECUs 31 and 32, and the engine ECU 31 constitutes the “vehicle control device”, but the present invention is not limited to this, and the vehicle control device is constituted by two or more ECUs. May be.

As the sensors, an accelerator sensor 41 that detects a depression operation amount (accelerator operation amount) of an accelerator pedal as an accelerator operation member, and a brake sensor 42 that detects a depression operation amount (brake operation amount) of a brake pedal as a brake operation member. A vehicle speed sensor 43 that detects the vehicle speed V, an inclination angle sensor 44 that detects the inclination angle of the road surface of the vehicle 10, a rotation speed sensor 45 that detects the engine rotation speed, a battery sensor 46 that detects the state of the battery 15, and the like are provided. The detection signals of these sensors are sequentially input to the engine ECU 31. In addition, this system is provided with a load sensor (air flow meter, intake pressure sensor) for detecting the engine load, a cooling water temperature sensor, an outside air temperature sensor, an atmospheric pressure sensor, etc., but they are not shown.

The engine ECU 31 performs various engine controls such as fuel injection amount control by a fuel injection valve and ignition control by an ignition device, engine start by ISG 13, engine torque assist and power generation control, and a brake device based on the detection results of various sensors. The brake control by 28 is performed. Further, the transmission ECU 32 carries out the on/off control of the clutch device 17 and the gear shift control of the transmission 18 based on the detection results of various sensors.

The vehicle 10 of the present embodiment has a function of coasting with the clutch device 17 in the disengaged state while the vehicle 11 is traveling by the operation of the engine 11. In addition, it has a function of performing regenerative traveling in which the clutch device 17 is connected to recover kinetic energy. This is intended to improve fuel efficiency.

FIG. 2 is an explanatory diagram showing an outline of each traveling state of the vehicle 10. For each running state,
(1) Normal traveling state (2) Inertia traveling state (3) Regenerative traveling state is defined, and the vehicle 10 shifts to each traveling state when a predetermined condition is satisfied. (1) The normal traveling state is a state in which the vehicle 11 is traveling with the engine 11 in the operating state and the clutch device 17 in the connected state (specifically, the state corresponding to the shift operation position by the driver). (2) The coasting state is a state in which the engine 11 is stopped and the clutch device 17 is disengaged to coast the vehicle 10. (3) The regenerative traveling state is a state in which the engine 11 is in the operating state (however, fuel injection is not performed), the clutch device 17 is in the connected state, and the ISG 13 performs regenerative power generation to drive the vehicle 10.

Here, the transition from the (1) normal traveling state to the (2) inertial traveling state and the transition from the (2) inertial traveling state to the (1) normal traveling state are performed according to the establishment of well-known conditions. It For example, when the vehicle 10 is in the (1) normal traveling state, the engine ECU 31 shifts the vehicle 10 to the (2) coasting state in response to the establishment of a predetermined coast execution condition including the accelerator condition and the brake condition. .. Note that the predetermined coast execution conditions include that the engine speed is stable at a predetermined value or higher (for example, idle speed or higher), the vehicle speed V is within a predetermined range (for example, 20 to 120 km/h), the road surface It is preferable that the gradient (inclination) be within a predetermined range. On the other hand, when the vehicle 10 is in the (2) coasting state, the engine ECU 31 shifts the vehicle 10 to the (1) normal traveling state in response to the establishment of a predetermined coast cancellation condition including the accelerator condition and the brake condition. .. At this time, it is preferable that the coasting state is canceled when the predetermined coast execution condition is not satisfied.

Further, the transition from the (1) normal traveling state to the (3) regenerative traveling state and the transition from the (3) regenerative traveling state to the (1) normal traveling state are performed according to the establishment of known conditions. .. For example, when the vehicle 10 is in the (1) normal running state, the engine ECU 31 sets the vehicle 10 in the (3) regenerative running state in response to the establishment of a predetermined regenerative execution condition including a braking condition and a storage state of the battery 15. Shift to. At this time, regenerative power generation is performed by the ISG 13, and kinetic energy is stored in the battery 15 as electric energy. On the other hand, when the vehicle 10 is in the (3) regenerative traveling state, the engine ECU 31 shifts to the (1) normal traveling state in response to the satisfaction of a predetermined regeneration cancellation condition including the accelerator condition.

Here, in this embodiment, the transition from the (2) inertial traveling state to the (3) regenerative traveling state and the transition from the (3) regenerative traveling state to the (2) inertial traveling state can be performed.

The transition from the (2) inertia traveling state to the (3) regenerative traveling state will be described in detail. When shifting from inertial running to regenerative running, it is necessary to connect the clutch device 17 in the disengaged state. In this case, the rotational speed of the engine output shaft 12 is adjusted in accordance with the rotational speed of the transmission input shaft 21 (that is, the rotational speed corresponding to the vehicle speed V) in order to reduce vibration and noise when the clutch is engaged, and in that state. It is desirable to connect the clutch device 17. In the present embodiment, the ISG 13 is driven to start the engine 11 to increase the engine rotation speed, and driving the ISG 13 consumes energy. Therefore, depending on the embodiment of the regenerative traveling, it is considered that the energy (consumed energy) consumed for increasing the engine rotation speed may be larger than the energy recovered by the regenerative traveling (regenerative energy). In such a case, it is not preferable from the viewpoint of improving fuel efficiency.

The relationship between energy consumption and regenerative energy will be described with reference to FIG. In addition, in FIG. 3, when a predetermined brake operation is performed during coasting (for example, when the amount of brake operation becomes larger than a predetermined threshold Th) based on the well-known coast cancellation condition, the coasting is stopped. It is planned to shift to regenerative driving. That is, in this case, the braking operation is included in the predetermined regeneration execution condition during coasting. The braking operation here may be braking operation by a driver or deceleration control (automatic braking, etc.) by a vehicle operation control unit.

In FIG. 3, before the timing t11, inertia running is performed, and in this state, the clutch is turned off (disengaged) and the engine 11 is stopped. Then, when the brake operation is performed at the timing t11, the control for shifting to the regenerative traveling is performed. That is, the engine 11 is started by driving the ISG 13, and the rotational force is applied to the engine output shaft 12. As a result, the engine rotation speed increases. Then, when the engine speed corresponding to the vehicle speed V is reached (timing t12), coasting is switched to regenerative running. At this time, the clutch is turned on (connected) and regenerative power generation by the ISG 13 is performed. After that, when the brake operation is released during the regenerative traveling (timing t13), the clutch is turned off and the regenerative traveling is switched to the coasting. Then, as the engine 11 is stopped along with the shift to the inertia running, the engine rotation speed converges to zero.

Then, at timing t14, when the brake operation amount increases again, the engine 11 is started by driving the ISG 13. Then, the engine rotation speed increases, and the inertia traveling is switched to the regenerative traveling at timing t15. After that, when the brake operation is released during the regenerative traveling and the accelerator operation is performed (timing t16), the regenerative traveling is switched to the normal traveling.

In FIG. 3, the vehicle 10 is in a coasting state before timing t12 and at timings t13 to t14, in a regenerative traveling state at timings t12 to t13 and timings t15 to t16, and in a normal traveling state after timing t16. ..

Here, the energy consumed when shifting to the regenerative traveling at the timings t12 to t13 is A1, the energy recovered at the regenerating traveling at the timings t12 to t13 is B1, and when shifting to the regenerative traveling at the timings t15 to t16. The energy consumed is A2, and the energy recovered in the regenerative traveling at timings t15 to t16 is B2. In this case, in the regenerative traveling at timings t15 to t16, the regenerative energy B2 is larger than the consumed energy A2, and the fuel consumption effect by the regenerative traveling is obtained. On the other hand, in the regenerative traveling from timing t12 to t13, the consumed energy A1 is larger than the regenerated energy B1, and the consumed energy cannot be recovered by the regenerated energy. That is, in the regenerative traveling at the timings t12 to t13, energy is lost by shifting from inertial traveling to regenerative traveling, which is considered to be disadvantageous from the viewpoint of energy efficiency.

Therefore, in the present embodiment, when the brake operation as the predetermined regenerative execution condition is performed during the coasting, the energy consumption consumed by the adjustment (increase) of the engine rotation speed is estimated and the energy is recovered by the regenerative traveling. Estimate the regenerated energy that is generated. Then, based on the comparison between the consumed energy and the regenerative energy, the transition from the inertia traveling to the regenerative traveling is performed. Specifically, when it is determined that the regenerative energy is larger than the consumed energy, the inertial traveling is canceled and the regenerative traveling is performed, and when the regenerated energy is determined to be smaller than the consumed energy, the inertial traveling is maintained. .. In other words, while allowing the transition from the inertia traveling to the regenerative traveling, the transition to the regenerative traveling, which is disadvantageous from the viewpoint of energy efficiency, is suppressed.

Aspects of this embodiment will be described with reference to FIG. At timing t11 when the brake operation is performed during coasting, the engine ECU 31 estimates the consumed energy A1 and the regenerative energy B1, respectively. When it is determined that the energy consumption A1 is larger than the regenerative energy B1, the inertia traveling is maintained without shifting from the inertia traveling to the regenerative traveling. That is, in this case, the clutch is kept off (disengaged) from timing t12 to timing t13, and the consumed energy A1 and the regenerative energy B1 are not generated. On the other hand, at the timing t14, it is determined that the regenerative energy B2 is larger than the consumed energy A2, and the inertia traveling is switched to the regenerative traveling at the timing t15. As described above, in the present embodiment, in FIG. 3, regenerative traveling at timings t12 to t13, which is disadvantageous in terms of energy efficiency, is not performed, whereas regenerative traveling at advantageous timings t15 to t16 is performed.

The engine ECU 31 estimates the consumed energy Erec and the regenerative energy Eregen when the brake operation is performed during coasting.

In the present embodiment, the energy consumption Erec refers to the energy required to rotate the engine output shaft 12 by the ISG 13. Specifically, the energy consumption Erec is estimated based on the sum of the required rotational energy calculated from the vehicle speed V and the loss energy including friction loss and the like. More specifically, it is estimated based on the following equation (1).

上記式（１）における各記号の定義について簡単に説明する。ｊはエンジン１１のイナーシャ（慣性モーメント）を表し、ωｔはエンジン１１の目標回転速度を表し、ω０は現時点のエンジン回転速度を表し、Plossは損失出力を表し、Tstは復帰目標時間を表し、EffmotはＩＳＧ１３の力行駆動における出力効率を表し、Effbatt_outはバッテリ１５の出力効率を表す。なお、損失出力は、エンジンフリクション等であり、公知の方法により算出することができる。

The definition of each symbol in the above formula (1) will be briefly described. j represents the inertia (inertia moment) of the engine 11, ωt represents the target rotation speed of the engine 11, ω0 represents the current engine rotation speed, Ploss represents the loss output, Tst represents the target recovery time, and Effmot Represents the output efficiency of the ISG 13 in the powering drive, and Effbatt_out represents the output efficiency of the battery 15. The loss output is engine friction or the like and can be calculated by a known method.

Here, ωt is calculated based on the vehicle speed V. In this case, ωt is calculated as a larger value as the vehicle speed V increases. On the other hand, since the engine 11 is stopped during coasting, ω0 is considered to be zero in most cases. In addition, it is considered that other parameters do not fluctuate significantly in their values during coasting. Then, it is considered that the energy consumption Erec largely depends on the vehicle speed V.

Further, the engine ECU 31 estimates the regenerative energy Eregen. In the present embodiment, the regenerative energy Eregen refers to energy that can be recovered by regenerative traveling. Specifically, the regenerative energy Eregen is estimated using the regenerative output Pregen calculated based on the brake operation amount and the regenerative continuation time Tgen predicted to continue regenerative traveling. More specifically, it is estimated based on the following equation (2).

上記式（２）における各記号の定義について簡単に説明する。EffgenはＩＳＧ１３の発電における出力効率を表し、Effbatt_inはバッテリ１５の入力効率を表す。ここで、回生継続時間Tgenは、適合等により予め定められた所定値であって、例えば１０秒である。

The definition of each symbol in the above formula (2) will be briefly described. Effgen represents the output efficiency of the ISG 13 during power generation, and Effbatt_in represents the input efficiency of the battery 15. Here, the regeneration continuation time Tgen is a predetermined value determined in advance by conformity or the like, and is, for example, 10 seconds.

Then, the engine ECU 31 controls the transition from the inertia traveling to the regenerative traveling by comparing the estimated consumed energy Erec and the regenerated energy Eregen.

Next, the traveling control process of the vehicle control device according to the present invention will be described with reference to the flowchart of FIG. This process is repeatedly executed by the engine ECU 31 at a predetermined cycle.

In FIG. 4, in step S11, it is determined whether or not the vehicle 10 is currently in the clutch-off inertia running state. If YES, the process proceeds to step S12, and if NO, the process proceeds to step S21. In step S12, it is determined whether or not the brake is on. The brake-on state is determined based on, for example, that the brake operation amount detected by the brake sensor 42 is greater than zero. If step S12 is YES, it will progress to step S13.

In step S13, the energy consumption Erec is estimated. The consumed energy Erec is estimated, for example, based on the above-mentioned formula (1). In step S14, the regenerative energy Eregen is estimated. The regenerative energy Eregen is estimated, for example, based on the above-mentioned formula (2). In step S15, it is determined whether the estimated regenerative energy Eregen is larger than the consumed energy Erec. When step S15 is YES, that is, when the regenerative energy Eregen is larger than the energy consumption Erec, the inertia traveling is canceled and the transition to the regenerative traveling is performed (step S16). If step S15 is NO, that is, if the consumed energy Erec is larger than the regenerative energy Eregen, inertia running is maintained (step S17).

On the other hand, if step S12 is NO, the process proceeds to step S18, and it is determined whether or not the accelerator is on. The accelerator-on state is determined based on, for example, that the accelerator operation amount detected by the accelerator sensor 41 is larger than 0. If step S18 is YES, inertia running will be cancelled|released and a transition to normal running will be implemented (step S19). If step S18 is NO, this process is ended as it is. That is, the vehicle 10 maintains the coasting state.

In addition, in step S21, it is determined whether or not the vehicle 10 is currently in the regenerative traveling state. If YES, the process proceeds to step S22, and if NO, the present process ends. In step S22, it is determined whether or not the accelerator is on. When step S22 is YES, that is, when the accelerator is in the state of being turned on during the regenerative traveling, the regenerative traveling is canceled and the transition to the normal traveling is performed (step S23).

On the other hand, if step S22 is NO, the process proceeds to step S24, and it is determined whether or not the brake is off. The brake-off state is determined based on, for example, that the brake operation amount detected by the brake sensor 42 is zero. In step S24, in addition to the brake off state, for example, the SOC of the battery 15 is equal to or higher than a predetermined value (for example, a value close to full charge), or the vehicle speed V is equal to or lower than a predetermined value (for example, 30 km/h). The following may be determined. If step S24 is YES, a transition from regenerative running to inertial running is performed (step S25). If step S24 is NO, this process is ended as it is. That is, the vehicle 10 maintains the regenerative traveling state.

Note that steps S13 and S14 correspond to the “estimation unit”, step S15 corresponds to the “determination unit”, and steps S16 and S17 correspond to the “travel control unit”.

As described above, when shifting from inertial running to regenerative running, energy consumption Erec is required as the engine speed increases (adjusts). On the other hand, the energy consumption Erec is not required when shifting from regenerative traveling to coasting. That is, the conditions for transition between coasting and regenerative running are different. It should be noted that the energy consumption Erec is also required when shifting from coasting to normal traveling.

According to this embodiment described in detail above, the following excellent effects can be obtained.

In the above configuration, when the brake operation is performed as the regeneration execution condition during coasting, the energy consumption Erec consumed by the adjustment of the engine speed is estimated and the regeneration energy Eregen collected by the regeneration traveling is estimated. To do. Then, based on the comparison between the consumed energy Erec and the regenerative energy Eregen, the transition from the inertia running to the regenerative running is performed. Specifically, when it is determined that the regenerative energy Eregen is larger than the consumed energy Erec, the transition from the inertia traveling to the regenerative traveling is performed, so that the energy equal to or more than the consumed energy Erec can be recovered by the regenerative traveling. In addition, when it is determined that the regenerative energy Eregen is smaller than the energy consumption Erec, the inertia running is maintained, so that the fuel efficiency effect of the inertia running is obtained and the shift to the disadvantageous regenerative running from the viewpoint of energy efficiency is achieved. Can be suppressed. Furthermore, the frequency of switching from coasting to regenerative driving can be suppressed, leading to improved drivability. Thereby, coasting and regenerative running can be appropriately switched.

The energy consumption Erec is energy required to rotate the engine output shaft 12 to a target engine rotation speed, and is considered to be correlated with the vehicle speed V. That is, when the vehicle speed V is high, the target engine rotation speed increases, and the energy consumption Erec also increases accordingly. In consideration of this point, since the energy consumption Erec is estimated based on the vehicle speed V, the energy consumption Erec can be estimated accurately. This makes it possible to properly determine the transition from coasting to regenerative traveling.

The regenerative energy Eregen is considered to correlate with the brake operation amount. For example, when the brake operation amount is large, the driver's deceleration request is large, and the regenerative energy Eregen is also large. In consideration of this point, since the regenerative energy Eregen is estimated based on the brake operation amount, the regenerative energy Eregen can be estimated accurately. This makes it possible to properly determine the transition from coasting to regenerative traveling.

(Modification of the first embodiment)
-In the said embodiment, although the structure which stopped the engine 11 during coasting is changed, this may be changed. For example, the configuration may be such that the engine rotation speed is maintained at the idle rotation speed (for example, 700 rpm) without stopping the engine 11 during coasting. In such a configuration, the range in which the engine speed is increased by driving the ISG 13 is smaller than that in the configuration in which the engine 11 is stopped. Therefore, the energy consumption Erec when shifting from coasting to regenerative traveling is reduced. Further, since the engine rotation speed is maintained at the idle rotation speed, the responsiveness at the time of canceling the coasting is improved as compared with the case where the engine 11 is stopped.

The engine rotation speed may be adjusted by means other than driving the ISG 13 when the brake operation is performed during coasting. For example, the engine speed is adjusted by the operation (combustion) of the engine 11. In this case, the energy required to drive the engine 11 may be estimated as the energy consumption Erec.

Further, the configuration may be such that the driving of the ISG 13 and the combustion of the engine 11 are combined to increase the engine rotation speed. Here, when increasing the engine rotation speed, in the low rotation speed range, the combustion efficiency of the engine 11 is poor, so it is considered that the driving by the ISG 13 is more efficient than the combustion of the engine 11. On the other hand, in the high rotation speed range, the combustion efficiency of the engine 11 is good. Considering this point, the drive of the ISG 13 and the combustion of the engine 11 may be selected according to the engine rotation speed. For example, in the low rotation speed range where the engine rotation speed is less than the predetermined value K, the ISG 13 is driven to increase the engine rotation speed, and in the high rotation speed range where the engine rotation speed is the predetermined value K or more, the combustion of the engine 11 occurs. Increase the engine speed. The predetermined value K is, for example, an idle rotation speed. In this case, for example, if the energy consumption Erec is estimated as the energy consumed by driving the ISG 13, the energy consumption Erec at the time of shifting from coasting to regenerative traveling is reduced.

Instead of the combination of driving the ISG 13 and the combustion of the engine 11, the engine rotation speed may be increased by a combination of a starter (not shown) and the combustion of the engine 11.

-In above-mentioned embodiment, although ISG13 was used as a regenerative device, a regenerative device is not restricted to this. For example, an alternator having only a power generation function may be used as the regenerative device, and a flywheel may be used as the regenerative device. In the latter case, the kinetic energy of the vehicle 10 is stored in the flywheel as rotational energy. At this time, a starter may be used as a device for starting the engine 11.

(Second embodiment)
In the second embodiment, when the regenerative energy Eregen is estimated, the SOC is acquired as a parameter indicating the power storage state of the battery 15, and the regenerative energy Eregen estimated based on the SOC is corrected.

For example, even if the transition from coasting to regenerative traveling is possible, the recovery of regenerative energy Eregen may be limited depending on the SOC of the battery 15. For example, when the SOC of the battery 15 is close to full charge, the power that can be charged in the battery 15 is small, and even if regenerative power generation is performed, there is a risk that the regenerative energy Eregen to be recovered will be limited. is there.

Therefore, when the regenerative energy Eregen is estimated, the engine ECU 31 acquires the SOC of the battery 15 and corrects the regenerated energy Eregen estimated based on the SOC. Then, the corrected regenerative energy Eregen is used to compare with the consumed energy Erec. Regarding the correction, for example, when the SOC of the battery 15 is close to full charge, the electric energy that can be charged in the battery 15 is small, so the estimated regenerative energy Eregen is corrected to a smaller side. The method of correction is not particularly limited, and for example, a method of multiplying the estimated regenerative energy Eregen by a coefficient α can be used. In this case, the SOC within the usage range of the battery 15 and the coefficient α (value of 0 or more and 1 or less) have a correlation as shown in FIG. 5, for example. In FIG. 5, the coefficient α is 1 when the SOC is less than or equal to the predetermined value P. In such a case, the regenerative energy Eregen does not change before and after the correction. On the other hand, when the SOC is equal to or higher than the predetermined value P, the coefficient α decreases as the SOC increases.

FIG. 6 is a flowchart showing the processing procedure of the travel control processing in the second embodiment, and this processing is replaced with FIG. 4 described above and is repeatedly executed by the engine ECU 31 at a predetermined cycle. In FIG. 6, the same steps as those in FIG. 4 are designated by the same step numbers to simplify the description. The changes from the processing of FIG. 4 are the addition of steps S31 and S32 and the modification of the processing content of step S15.

In FIG. 6, when the vehicle 10 is in the coasting state and the brake is on (steps S11 and S12 are both YES), the energy consumption Erec is estimated (step S13), and the regenerative energy Eregen is estimated. Is estimated (step S14). In subsequent step S31, engine ECU 31 obtains the SOC of battery 15. In step S32, the regenerative energy Eregen is corrected based on the acquired SOC. Specifically, the regenerative energy Eregen is corrected based on the above-described correlation between the SOC and the coefficient α.

Then, in step S15, it is determined whether the corrected regenerative energy Eregen is larger than the consumed energy Erec. If step S15 is YES, it will progress to step S16 and a transition to regenerative running will be implemented. If step S15 is NO, it will progress to step S17 and coasting will be maintained. Note that step S32 corresponds to the “correction unit”.

In the above configuration, the regenerative energy Eregen is corrected based on the SOC of the battery 15. Therefore, in addition to the energy balance between the consumed energy Erec and the regenerative energy Eregen, the state of the side that stores the regenerative energy Eregen can be taken into consideration. The shift to regenerative traveling, which is disadvantageous from the viewpoint of energy efficiency, can be suitably suppressed.

(Modification of the second embodiment)
In the second embodiment described above, the regenerative energy Eregen is corrected based on the SOC of the battery 15, but the regenerative energy Eregen may be corrected based on another parameter indicating the state of the battery 15. For example, the regenerative energy Eregen may be corrected based on the temperature of the battery 15.

Further, the regenerative energy Eregen may be corrected based on the parameter indicating the state of the ISG 13. That is, in this case, the regenerative energy Eregen is corrected in consideration of the state of the energy recovery side. For example, in the configuration for correcting the regenerative energy Eregen based on the temperature of the ISG 13, the temperature of the ISG 13 (for example, the temperature of the switching element of the inverter unit, the temperature of the stator of the motor unit) is acquired in step S31 in FIG. In step S32, the regenerative energy Eregen is corrected based on the temperature. Even if the transition from coasting to regenerative traveling is possible, regenerative power generation is considered to be limited when the temperature of ISG 13 is equal to or higher than a predetermined value. In consideration of this point, by correcting the regenerative energy Eregen based on the temperature of the ISG 13, in addition to the energy balance, it is possible to take into consideration the state of the side for recovering energy, which leads to a disadvantageous regenerative traveling from the viewpoint of energy efficiency. Can be suitably suppressed.

-In the said 2nd Embodiment, although the method of multiplying the coefficient (alpha) was used as a method of correction|amendment of regenerative energy Eregen, it is not restricted to this. For example, the battery receivable energy is calculated based on the SOC of the battery 15 and the battery capacity, and a smaller value of the calculated battery receivable energy and the estimated regenerative energy Eregen may be used as the regenerative energy after correction Eregen. Good.

In the second embodiment, the regenerative energy Eregen is corrected based on the SOC. However, for example, when the SOC is equal to or higher than a predetermined value, the transition from inertial running to regenerative running may be prohibited. In such a configuration, the predetermined value is set to, for example, SOC close to full charge. In addition, a configuration may be adopted in which the transition from coasting to regenerative traveling is prohibited based on a parameter indicating the state of the battery 15 such as the temperature of the battery 15 or a parameter indicating the state of the ISG 13. In the latter case, for example, when the temperature of the ISG 13 (for example, the temperature of the switching element of the inverter unit or the temperature of the stator of the motor unit) is equal to or higher than a predetermined value, the transition to regenerative traveling is prohibited and coasting is maintained. You may do so.

(Third Embodiment)
In the said 1st Embodiment, it was set as the structure which uses the preset predetermined value as regeneration continuation time Tgen. Here, since the tendency of vehicle traveling differs depending on the vehicle 10 and the driver, it is considered that the duration of regenerative traveling differs due to this. Furthermore, since the traveling condition varies depending on the regenerative traveling each time, it is considered that the duration of the regenerative traveling differs due to this.

Therefore, in the third embodiment, when the brake operation is performed during the inertia running, the past duration is acquired according to the running condition of the vehicle 10, and the current duration (regeneration is performed based on the duration. Set duration Tgen). Then, the regenerative energy Eregen is estimated using the set regeneration duration Tgen.

The engine ECU 31 stores the duration of the regenerative traveling as a history in a memory or the like in the engine ECU 31 for each traveling condition in each regenerative traveling in the past. The traveling conditions include, for example, the vehicle speed V and the road gradient. In this case, it is considered that the higher the vehicle speed V, the longer the duration of the regenerative traveling. Moreover, it is considered that the steeper the road gradient, the longer the duration of regenerative running becomes.

FIG. 7 illustrates a processing procedure for estimating the regenerative energy Eregen in step S14 of FIG. This processing is executed by the engine ECU 31 as a subroutine processing when step S14 of FIG. 4 is executed. That is, in FIG. 4, when the vehicle 10 is in the coasting state and the brake is on (when both steps S11 and S12 are YES), the energy consumption Erec is estimated (step S13). , And proceeds to step S101 in FIG.

In step S101, the traveling condition of the vehicle 10 is acquired. For example, the vehicle speed V is acquired based on the value detected by the vehicle speed sensor 43, and the road surface slope is acquired based on the value detected by the inclination angle sensor 44. In step S102, the duration of past regenerative travel is acquired according to the acquired travel conditions. For example, the duration of the regenerative traveling that has been performed in the past at the vehicle speed V that is approximately the same as the current vehicle speed V is acquired. The road surface gradient may be taken into consideration. In step S103, the current regeneration duration Tgen is set based on the obtained duration. Here, for example, the average value of the continuation times of the past ten times of regenerative travel under similar travel conditions is set as the regeneration continuation time Tgen. Then, in step S104, the regenerative energy Eregen is estimated based on the set regeneration continuation time Tgen, and the process returns to step S15 in FIG. In the present embodiment, step S103 corresponds to the “setting section” and step S104 corresponds to the “estimation section”.

The regenerative energy Eregen is considered to correlate with the duration of regenerative running. In consideration of this point, in the above configuration, when the braking operation is performed during the inertia running, the regeneration duration time Tgen is set as the current duration time, and based on the set regeneration duration time Tgen and the brake operation amount. Since the regenerative energy Eregen is estimated by the above method, the regenerative energy Eregen can be accurately estimated.

In addition, since the duration is stored each time regenerative traveling is performed, and the regenerative duration Tgen is set based on the history of the stored duration, the regenerative traveling for each vehicle 10 is adjusted according to the tendency. The regeneration duration Tgen can be set appropriately. Furthermore, since the history of past durations is acquired according to the traveling conditions of the vehicle 10 and the regeneration duration Tgen is set based on the history, the conditions affecting the duration of regenerative traveling are taken into consideration. The regeneration duration Tgen can be set. As a result, the regeneration duration time Tgen can be appropriately set according to the operating condition each time, and the regenerative energy Eregen can be accurately estimated.

(Modification of Third Embodiment)
In the third embodiment described above, the regeneration duration time Tgen is set based on the past duration time of the regeneration run stored in the memory or the like, but this may be changed. For example, the regeneration duration time Tgen may be set each time based on the traveling condition of the vehicle 10. With such a configuration, for example, a correlation map as shown in FIG. 8 can be used. In FIG. 8, the regeneration duration time Tgen is longer as the vehicle speed V is higher, and the regeneration duration time Tgen is longer as the road gradient is steeper. Further, the regeneration duration time Tgen may be set by utilizing traffic information such as traffic lights and traffic congestion on roads. In this case, for example, if the traffic signal existing in the traveling direction of the vehicle 10 is a red traffic light, the vehicle 10 needs to be stopped, so the regeneration duration time Tgen is set to be short.

(Fourth Embodiment)
Next, the fourth embodiment will be described focusing on the differences from the first embodiment. FIG. 9 shows a schematic configuration of the vehicle control system in the fourth embodiment. The fourth embodiment is directed to a vehicle control system including a transmission 51 between the engine output shaft 12 and the rotating shaft 14 of the ISG 13. The transmission 51 can change the speed ratio (rotational speed of the rotating shaft 14/rotational speed of the engine output shaft 12) of the rotational power by the ISG 13. If the rotation speed of the engine output shaft 12 is N1 and the rotation speed of the rotation shaft 14 is N2, the gear ratio is N2/N1. The engine ECU 31 controls the gear ratio of the transmission 51 according to the state of the vehicle 10. Note that the configuration is the same as that of FIG. 1 except that the transmission 51 is provided.

In the first embodiment, FIG. 2 shows the control when shifting from the (2) inertial traveling state to the (3) regenerative traveling state, but in the fourth embodiment, particularly in the (2) inertial traveling state. The control of is shown below. When the vehicle 10 shifts to coasting, the engine 11 is stopped and the engine rotation speed decreases as time passes.

In the fourth embodiment, the gear ratio of the transmission 51 is changed to a side that suppresses the decrease in the engine rotation speed during coasting. Specifically, when the vehicle 10 is in the normal traveling state and a predetermined coast execution condition is satisfied, the gear ratio (rotational speed of the rotary shaft 14/rotational speed of the engine output shaft 12) is set to be lower than the previous gear ratio. Enlarge. Then, the vehicle 10 is switched to coasting with the gear ratio increased, and coasting is performed. Then, the gear ratio is reduced when the coasting is changed to the normal traveling. That is, the increased gear ratio is restored.

In this case, by increasing the gear ratio before shifting to coasting, it is possible to collect the kinetic energy during deceleration as rotational energy by the ISG 13, and then shift to coasting. As a result, the inertia of the engine 11 during coasting increases, the decrease in the engine rotation speed during coasting is suppressed, and the period during which the engine output shaft 12 rotates during coasting can be extended. As a result, for example, when the inertia traveling is canceled in a short time, the rotation of the engine output shaft 12 is ensured, so that the energy consumption Erec accompanying the shift can be reduced. In addition, here, the transition between the normal traveling and the coasting is shown, but the transition between the regenerative traveling and the coasting is the same.

The processing procedure of the shift control of the transmission 51 by the engine ECU 31 will be described with reference to the flowchart of FIG. This process is repeatedly executed by the engine ECU 31 at a predetermined cycle.

In step S41, it is determined whether the vehicle 10 is currently in the non-inertia traveling state (normal traveling state or regenerative traveling state). If step S41 is YES, it will progress to step S42, and if step S41 is NO, it will progress to step S46. In step S42, it is determined whether or not the coast execution condition is satisfied. For example, regarding the transition from normal traveling to coasting, it is determined that the accelerator is off and the brake is off. If step S42 is YES, it will progress to step S43, and if step S42 is NO, this process will be complete|finished as it is.

In step S43, the gear ratio of the transmission 51 is increased. Specifically, the gear ratio is changed so that the rotation speed of the rotation shaft 14 of the ISG 13 is higher than the rotation speed of the engine output shaft 12. In step S44, it is determined whether or not a predetermined time T has elapsed since the gear ratio of the transmission 51 was changed. The kinetic energy is recovered as rotational energy by the ISG 13 while the predetermined time T elapses. Then, when the predetermined time T has passed (S44: YES), the process proceeds to step S45, the clutch is turned off (disengaged), and the coasting is performed.

When the vehicle 10 shifts to the coasting state and step S46 is positive, the process proceeds to step S47. In step S47, it is determined whether or not the coast cancellation condition is satisfied. For example, regarding transition to normal traveling, it is determined whether or not the accelerator has been turned on. Regarding the transition to regenerative traveling, it is determined whether the brake is in the on state and the regenerative energy Eregen is larger than the consumed energy Erec. If step S47 is YES, it will progress to step S48 and the drive of ISG13 will be started.

In a succeeding step S49, it is determined whether or not it is a transition timing to the normal traveling or the regenerative traveling. Specifically, the engine ECU 31 determines whether or not the engine rotation speed has risen to the rotation speed corresponding to the vehicle speed V by driving the ISG 13. Then, when it is determined that it is the transition timing (step S49: YES), the process proceeds to step S50. In step S50, the gear ratio of the transmission 51 is reduced. That is, the gear ratio is returned to the state before the coast execution condition is satisfied. In step S51, the inertia traveling is canceled and the normal traveling or the regenerative traveling is performed. On the other hand, if step S46 and step S47 are NO, this process is ended as it is. Note that steps S43 and S50 correspond to the "shift control unit".

Subsequently, FIG. 11 shows a timing chart showing the processing of FIG. 10 more specifically. Here, reference control (control that does not change the transmission ratio of the transmission 51) and control in the present embodiment (control that changes the transmission ratio of the transmission 51) are shown. In FIG. Then, the control in the present embodiment is shown by a solid line. Note that FIG. 11 shows a scene in which the vehicle 10 shifts from the normal traveling state to the inertial traveling state, and then shifts from the inertial traveling state to the regenerative traveling state.

First, the reference control will be described. In this control, the gear ratio of the transmission 51 remains LOW regardless of the traveling state. Prior to the timing t21, the normal running is shown, and in this state, the clutch is on (connected). When the coast execution condition is satisfied at the timing t21, the clutch is turned off (disengaged), and the normal traveling is switched to the coasting. Then, as the engine 11 stops, the engine rotation speed decreases, and the engine rotation speed becomes zero at timing t23. After that, when the regeneration execution condition is satisfied at timing t24, the driving of the ISG 13 is started, and the engine rotation speed increases. After that, the inertia traveling is switched to the regenerative traveling at the timing t25. In this reference control, it is necessary to increase the engine speed by ΔNE1 when shifting to regenerative running.

On the other hand, in the control of this embodiment, the gear ratio of the transmission 51 is changed from LOW to HIGH at the timing t21 when the coast execution condition is satisfied. That is, in this case, the gear ratio is made larger than the gear ratio in the standard control. Then, the kinetic energy is collected, and the clutch is disengaged and the coasting mode is switched to at timing t22 after elapse of the predetermined time T. That is, in this case, the predetermined time T is a delay time from the satisfaction of the coast execution condition to the actual start of coasting. After that, the engine rotation speed decreases, but the decrease speed becomes slower than in the standard control. Then, when the regeneration execution condition is satisfied at the timing t24, the driving of the ISG 13 is started, and the inertia traveling is switched to the regenerative traveling at the timing t25. In the control according to the present embodiment, it is necessary to increase the engine rotation speed by ΔNE2 when shifting to regenerative running.

Here, in the control according to the present embodiment, the increase range of the engine rotation speed due to the driving of the ISG 13 is smaller than the reference control (ΔNE2<ΔNE1). That is, by increasing the gear ratio in coasting, the energy consumption Erec when shifting from coasting to non-coasting can be reduced.

In the above configuration, the gear ratio is changed to a side that suppresses a decrease in engine rotation speed during coasting. Specifically, the gear ratio is changed from LOW to HIGH when the coast execution condition is satisfied, and the inertia running is executed in the HIGH state. In this case, by setting the gear ratio to HIGH, it is possible to suppress a decrease in the engine speed as compared with the case where the inertia running is performed at LOW. As a result, the period during which the engine output shaft 12 rotates can be extended, and as a result, the energy consumption Erec can be reduced when shifting from coasting to non-coasting.

When traveling by combustion of the engine 11, the ISG 13 is rotated together, and sliding loss occurs due to the rotation. In consideration of this point, the gear ratio is changed from HIGH to LOW when the inertia traveling is canceled, that is, when the transition from the inertia traveling to the non-inert traveling (normal traveling and regenerative traveling) is performed. In this case, the rotation speed of the ISG 13 with respect to the engine rotation speed in the non-inertia traveling becomes smaller than that in the coasting. As a result, it is possible to reduce the sliding loss due to the rotation of the ISG 13 during non-inertia traveling, and it is possible to suitably perform traveling by combustion of the engine 11. Further, in the configuration in which the cooling fan is drivingly connected to the rotating shaft 14 of the ISG 13, the rotation speed of the ISG 13 is reduced, so that the rotating sound of the cooling fan can be reduced.

(Modification of Fourth Embodiment)
In the fourth embodiment described above, the gear ratio is reduced when the coasting is released (the state before the coast execution condition is satisfied), but the timing for reducing the gear ratio is not limited to this. For example, the gear ratio may be reduced when the engine rotation speed reaches a predetermined threshold value NEth during a period in which the engine rotation speed is increased by driving the ISG 13 during the transition from coasting to regenerative driving.

In this case, for example, as a step to proceed when step S49 of FIG. 10 is NO, a step of determining whether or not the engine speed is equal to or higher than the threshold value NEth is provided. If the engine rotation speed is equal to or higher than the threshold value NEth, the process proceeds to step S50 to reduce the gear ratio. That is, the gear ratio is reduced before the inertia running is canceled. On the other hand, if the engine rotation speed is less than the threshold value NEth, this processing is ended as it is. The threshold value NEth is set to a value larger than the engine rotation speed range where a large torque (override torque) is required at the time of engine start. According to this configuration, by reducing the gear ratio at a timing when a large torque is not required at the time of starting the engine, it is possible to reduce the sliding loss of the ISG 13 prior to the cancellation of the coasting, and thus the non-coasting traveling. It is possible to reduce the energy consumption Erec that accompanies the shift to.

In the fourth embodiment, the transmission 51 is provided between the engine output shaft 12 and the rotary shaft 14 of the ISG 13, but the transmission 51 is limited to this as long as the gear ratio of the rotational power by the ISG 13 is variable. Not done. For example, a configuration may be adopted in which the ISG 13 is provided with a gear shift function and the ISG 13 changes the gear ratio.

-In the said 4th Embodiment, it may replace with ISG13 and may use the alternator which has only a power generation function, or the rotary machine (flywheel etc.) which does not have a power generation function, for example. In such a configuration, a transmission is provided between the engine output shaft 12 and a rotating shaft such as an alternator, and the gear ratio of the transmission is changed to a side that suppresses a decrease in engine rotation speed during coasting.

(Fifth Embodiment)
When performing regenerative power generation, the engine ECU 31 transmits a power generation command to the ISG 13. At this time, the engine ECU 31 sets the regeneration request output based on the amount of brake operation, the state of charge of the battery 15, and the like. Then, the ISG 13 is caused to perform regenerative power generation based on the regenerative request output. As a result, electric power according to the state of the vehicle 10 is obtained by regenerative power generation.

On the other hand, in order to prevent the temperature of the ISG 13 from excessively rising due to the power generation operation of the regenerative power generation, an output limit may be set for the regenerative power generation of the ISG 13. Therefore, even if the regenerative demand output is large, the regenerative power generation may be suppressed to the predetermined output value Wth or less due to the output limitation, and in that case, the recovery of the regenerative energy Eregen is limited. The output limitation of the regenerative power generation is set in consideration of the duration of the regenerative traveling, and is set on the assumption of the regenerative traveling for about 30 seconds, for example.

In the present embodiment, the engine ECU 31 sets the regeneration continuation time Tgen and the regeneration request output when the regeneration execution condition is satisfied. If the regeneration duration time Tgen is equal to or less than the predetermined threshold value TA and the regeneration request output is equal to or greater than the predetermined threshold value WA, the regenerative power generation with the output larger than the output value Wth is permitted. Here, the threshold value TA is a determination value for determining regenerative running for an extremely short time, and is set to, for example, 3 seconds. The threshold value WA is set to a value corresponding to the output limit of regenerative power generation. That is, in this case, regenerative power generation with a large output (output that exceeds the output limit of regenerative power generation) is performed in an extremely short time. As a result, the regenerative energy Eregen can be efficiently collected.

A processing procedure of regenerative power generation by the engine ECU 31 will be described with reference to the flowchart of FIG. This process is repeatedly executed by the engine ECU 31 at a predetermined cycle.

In step S61, it is determined whether the vehicle 10 is currently in the non-regenerative traveling state (normal traveling state or coasting state). If step S61 is YES, it will progress to step S62, and if step S61 is NO, this process will be complete|finished as it is. In step S62, it is determined whether the regenerative execution condition is satisfied. For example, regarding the transition from coasting to regenerative traveling, it is determined whether the brake is in the on state and the regenerative energy Eregen is larger than the consumed energy Erec. If step S62 is YES, it will progress to step S63, and if step S62 is NO, this process will be complete|finished as it is.

In step S63, the regeneration continuation time Tgen is set. For example, the regeneration continuation time Tgen is set similarly to the process of step S103 in FIG. In the following step S64, the regeneration request output is set. For example, the braking operation amount and the road surface gradient are applied to the map shown in FIG. 13 to set the regeneration request output. In the map of FIG. 13, the larger the brake operation amount, the larger the regenerative request output, and the steeper the road surface slope, the larger the regenerative request output. The road surface gradient is acquired by the inclination angle sensor 44, GPS information, a gyro sensor (not shown), and the like. Note that steps S63 and S64 correspond to the "setting section".

In step S65, it is determined whether the regeneration duration time Tgen is less than or equal to the threshold value TA and the regeneration request output is greater than or equal to the threshold value WA. If NO in step S65, the process proceeds to step S66, and regenerative power generation is performed at an output value Wth or less. That is, in this case, regenerative power generation is performed within the range of normal output limitation. On the other hand, if step S65 is YES, the process proceeds to step S67, and regenerative power generation with an output larger than the output value Wth is permitted. Specifically, the engine ECU 31 transmits a power generation command to the ISG 13 to generate power with an output larger than Wth, and regenerative power generation is performed. Note that step S67 corresponds to the "permission unit".

Further, when regenerative power generation is performed by the ISG 13, excitation of the rotor of the motor unit of the ISG 13 is started based on a power generation command from the engine ECU 31, and regenerative power generation is performed after the excitation is completed. That is, it takes time to complete the excitation of the rotor, and when regenerative power generation is performed in an extremely short time, the time required for this excitation greatly affects the power generation efficiency.

Therefore, in order to efficiently perform the regenerative power generation in an extremely short time, the engine ECU 31 may cause the ISG 13 to start the regenerative power generation preparatory operation before the regenerative execution condition is satisfied. Specifically, the engine ECU 31 causes the ISG 13 to start exciting the rotor when the brake operation amount becomes equal to or more than the threshold Th1. In this configuration, the regeneration operation condition is set so that the brake operation amount is equal to or greater than the threshold Th2, and the magnitude relationship between the threshold Th1 and the threshold Th2 is Th1<Th2. Therefore, when the brake operation is performed in the non-regenerative traveling state, the excitation of the rotor is first started when the brake operation amount becomes the threshold Th1 or more, and the regenerative power generation is performed when the brake operation amount becomes the threshold Th2 or more thereafter. That is, according to such a configuration, the excitation of the rotor is started before the power generation command from the engine ECU 31, so that the regenerative power generation is promptly performed, and the regenerative energy Eregen is efficiently generated even in the extremely short time regenerative power generation. Can be recovered.

In the above configuration, when the regeneration execution condition is satisfied, when the regeneration duration time Tgen is equal to or less than the threshold value TA and the regeneration request output is equal to or greater than the threshold value WA, regenerative power generation with an output larger than the output value Wth is permitted. I did it. For example, when the regeneration duration time Tgen is extremely short and the required regeneration output is large, regenerative power generation with an output larger than the output value Wth is possible. In this case, if the regenerative power generation time is extremely short, the temperature rise of the ISG 13 can be suppressed even if the regenerative power generation is performed above the output limit. As a result, it is possible to efficiently recover the regenerative energy Eregen corresponding to the regenerative request output while suppressing the excessive temperature rise of the ISG 13.

(Modification)
In the above-described embodiment, the ISG 13 in which the generator and the electric motor are integrated is provided as the regenerative device, but the alternator (generator) as the regenerative device and the electric motor that imparts rotational force to the engine output shaft 12 are provided respectively. It may be configured.

10... Vehicle, 11... Engine, 12... Engine output shaft, 13... ISG, 17... Clutch device, 31... Engine ECU.

Claims (15)

An engine (11) as a travel drive source, a clutch device (17) provided in a power transmission path connected to an output shaft (12) of the engine, and a regenerative device (for recovering kinetic energy of the vehicle via the output shaft ( 13) and a vehicle (10) comprising
In response to the satisfaction of a predetermined coasting execution condition, the clutch device is disengaged to carry out the coasting of the vehicle, and the engine speed is adjusted according to the satisfaction of a predetermined regeneration execution condition during coasting. A travel control unit that performs the transition from the inertial travel to the regenerative travel using the regenerative device by connecting the clutch device,
When the brake operation as the regeneration execution condition is performed during the inertia traveling, the energy consumption consumed by the adjustment of the engine speed is estimated and the regeneration energy recovered by the regeneration traveling is estimated. Department,
A determination unit that determines that the regenerative energy estimated by the estimation unit is larger than the consumed energy,
Equipped with
In the vehicle, it is possible to apply a rotating force to the output shaft by a rotating machine (13),
The traveling control unit performs a transition from the inertia traveling to the regenerative traveling when it is determined that the regenerative energy is larger than the consumed energy, and it is determined that the regenerated energy is smaller than the consumed energy. In the case where the inertia traveling is maintained, and when the engine rotation speed is less than a predetermined value when shifting from the inertia traveling to the regenerative traveling, the rotating machine is operated to increase the engine rotation speed and the engine rotation. A vehicle control device for increasing the engine rotation speed by combustion of the engine if the speed is equal to or higher than a predetermined value. The regenerative device is a rotating machine (13), and is applied to a vehicle in which a gear ratio between the output shaft and a rotating shaft (14) of the rotating machine is variable,
The vehicle control device according to claim 1, further comprising a shift control unit that changes the gear ratio to a side that suppresses a decrease in the engine rotation speed during the coasting. The gear ratio is a ratio of the rotation speed of the rotation shaft of the rotating machine to the rotation speed of the output shaft,
3. The shift control unit according to claim 2, wherein when the predetermined coasting execution condition is satisfied, the shift control unit makes the gear ratio larger than before, and when the coasting is released, the gear ratio becomes smaller. Vehicle control device. An engine (11) as a travel drive source, a clutch device (17) provided in a power transmission path connected to an output shaft (12) of the engine, and a regenerative device (for recovering kinetic energy of the vehicle via the output shaft ( 13), wherein the regenerative device is a rotating machine (13), and a gear ratio between the output shaft and the rotating shaft (14) of the rotating machine is variable. Applied,
In response to the satisfaction of a predetermined coasting execution condition, the clutch device is disengaged to carry out the coasting of the vehicle, and the engine speed is adjusted according to the satisfaction of a predetermined regeneration execution condition during coasting. A travel control unit that performs the transition from the inertial travel to the regenerative travel using the regenerative device by connecting the clutch device,
When the brake operation as the regeneration execution condition is performed during the inertia traveling, the energy consumption consumed by the adjustment of the engine speed is estimated and the regeneration energy recovered by the regeneration traveling is estimated. Department,
In the inertia running, the gear ratio is changed to a side that suppresses a decrease in the engine rotation speed,
A determination unit that determines that the regenerative energy estimated by the estimation unit is larger than the consumed energy,
Equipped with
The traveling control unit performs a transition from the inertia traveling to the regenerative traveling when it is determined that the regenerative energy is larger than the consumed energy, and it is determined that the regenerated energy is smaller than the consumed energy. In case of maintaining the inertia running,
The gear ratio is a ratio of the rotation speed of the rotation shaft of the rotating machine to the rotation speed of the output shaft,
The shift control unit is a vehicle control device that increases the shift ratio when the predetermined coasting execution condition is satisfied, and reduces the shift ratio when the coasting is canceled. The gear ratio is a ratio of the rotation speed of the rotation shaft of the rotating machine to the rotation speed of the output shaft,
When the predetermined coasting execution condition is satisfied, the shift control unit increases the gear ratio more than before, and when the engine rotation speed becomes equal to or higher than a predetermined rotation speed due to the adjustment of the engine rotation speed. The vehicle control device according to claim 2, wherein the gear ratio is reduced. An engine (11) as a travel drive source, a clutch device (17) provided in a power transmission path connected to an output shaft (12) of the engine, and a regenerative device (for recovering kinetic energy of the vehicle via the output shaft ( 13), wherein the regenerative device is a rotating machine (13), and a gear ratio between the output shaft and the rotating shaft (14) of the rotating machine is variable. Applied,
In response to the satisfaction of a predetermined coasting execution condition, the clutch device is disengaged to carry out the coasting of the vehicle, and the engine speed is adjusted according to the satisfaction of a predetermined regeneration execution condition during coasting. A travel control unit that performs the transition from the inertial travel to the regenerative travel using the regenerative device by connecting the clutch device,
When the brake operation as the regeneration execution condition is performed during the inertia traveling, the energy consumption consumed by the adjustment of the engine speed is estimated and the regeneration energy recovered by the regeneration traveling is estimated. Department,
A determination unit that determines that the regenerative energy estimated by the estimation unit is larger than the consumed energy,
In the inertia running, the gear ratio is changed to a side that suppresses a decrease in the engine rotation speed,
Equipped with
The traveling control unit performs a transition from the inertia traveling to the regenerative traveling when it is determined that the regenerative energy is larger than the consumed energy, and it is determined that the regenerated energy is smaller than the consumed energy. In case of maintaining the inertia running,
The gear ratio is a ratio of the rotation speed of the rotation shaft of the rotating machine to the rotation speed of the output shaft,
When the predetermined coasting execution condition is satisfied, the shift control unit increases the gear ratio more than before, and when the engine rotation speed becomes equal to or higher than a predetermined rotation speed due to the adjustment of the engine rotation speed. A vehicle control device for reducing the gear ratio. The said estimation part estimates the said regenerative energy based on the brake operation amount, when the brake operation as the said regeneration execution condition is implemented during the said inertia running, The any one of Claim 1 thru|or 6. Vehicle control device. When the brake operation is performed during the inertia running, a setting unit for setting the duration of the regenerative running is provided,
The vehicle control device according to claim 7, wherein the estimation unit estimates the regenerative energy based on the brake operation amount and the duration. When the regenerative traveling is carried out, a storage unit for storing the duration is provided,
The vehicle control device according to claim 8, wherein the setting unit sets the duration based on a history of the duration stored in the storage. The storage unit stores the duration for each of the traveling conditions of the vehicle determined in plural,
The setting unit acquires the history according to a traveling condition of the vehicle and sets the duration based on the history when the brake operation is performed during the inertia traveling. The vehicle control device described. The regenerative device is a rotating electric machine (13) that performs regenerative power generation for recovering kinetic energy of the vehicle as electric energy, and is applied to a vehicle in which the regenerative power generation by the rotating electric machine is performed at a predetermined output or less,
When the brake operation is performed during the inertia traveling, a setting unit that sets a duration of the regenerative traveling and a required output that requests the regenerative traveling,
When the duration is a predetermined time or less, and when the required output is a predetermined output or more, a permission unit that permits the regenerative power generation with an output larger than the predetermined output,
The vehicle control device according to any one of claims 1 to 7, further comprising: An engine (11) as a travel drive source, a clutch device (17) provided in a power transmission path connected to an output shaft (12) of the engine, and a regenerative device (for recovering kinetic energy of the vehicle via the output shaft ( 13), wherein the regenerative device is a rotating electric machine (13) for performing regenerative power generation for recovering kinetic energy of the vehicle as electric energy, and the regenerative power generation by the rotating electric machine. Is applied to the vehicle that is carried out below the predetermined output,
In response to the satisfaction of a predetermined coasting execution condition, the clutch device is disengaged to carry out the coasting of the vehicle, and the engine speed is adjusted according to the satisfaction of a predetermined regeneration execution condition during coasting. A travel control unit that performs the transition from the inertial travel to the regenerative travel using the regenerative device by connecting the clutch device,
When the brake operation as the regeneration execution condition is performed during the inertia traveling, the energy consumption consumed by the adjustment of the engine speed is estimated and the regeneration energy recovered by the regeneration traveling is estimated. Department,
A determination unit that determines that the regenerative energy estimated by the estimation unit is larger than the consumed energy,
When the brake operation is performed during the inertia traveling, a setting unit that sets a duration of the regenerative traveling and a required output that requests the regenerative traveling,
When the duration is a predetermined time or less, and when the required output is a predetermined output or more, a permission unit that permits the regenerative power generation with an output larger than the predetermined output,
Equipped with
The traveling control unit performs a transition from the inertia traveling to the regenerative traveling when it is determined that the regenerative energy is larger than the consumed energy, and it is determined that the regenerated energy is smaller than the consumed energy. In some cases, the vehicle control device maintains the coasting . The said estimation part estimates the said energy consumption based on the vehicle speed of the said vehicle, when the brake operation as the said regeneration implementation conditions is implemented during the said inertia running, 13. Vehicle control device. The regenerative device is a rotating electric machine (13) that performs regenerative power generation for recovering kinetic energy of the vehicle as electric energy,
14. The vehicle control device according to claim 1, further comprising a correction unit that corrects the regenerative energy estimated by the estimation unit based on a state of a storage battery that stores electric power generated by the rotating electric machine. .. The regenerative device is a rotating electric machine (13) that performs regenerative power generation for recovering kinetic energy of the vehicle as electric energy,
The vehicle control device according to claim 1, further comprising a correction unit that corrects the regenerative energy estimated by the estimation unit based on a state of the rotating electric machine.

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