Vehicle control device

Abstract

Vehicle control device applied to a vehicle (10) with a machine (11) as a drive source, a coupling device (17) arranged in a motion force transmission path coupled to an output shaft (12) of the machine (11), and a regeneration device (13) for recovering kinetic energy of the vehicle (10) via the output shaft (12), wherein the vehicle control device comprises: a driving control section (S16, S17) that disengages the clutch device (17) to implement overrun operation by the vehicle (10) in response to a predetermined condition for implementing overrun operation that is established, and that performs a transition from overrun operation to regenerative driving using the regeneration device (13) by setting an engine speed and engaging the clutch device (17) in response to a predetermined condition for implementing regeneration that is established during overrun operation, and an estimation section (S13, S14) which, when a brake application is performed as the condition for implementing regeneration during overrun operation, estimates consumed energy as energy consumed by adjusting the engine speed and estimates regeneration energy as energy recovered by regenerative driving; wherein a rotational force can be applied to the output shaft (12) of a lathe (13) in the vehicle (10), the driving control section (S16, S17) performs the transition from overrun to regenerative driving based on a comparison between the energy consumed and the energy regenerated, and If the engine speed is less than a predetermined value when the transition from overrun to regenerative driving is performed, the drive control section (S16, S17) increases the engine speed by driving the output shaft (12) through the lathe (13), whereas if the engine speed is greater than or equal to the predetermined value, the drive control section (S16, S17) increases the engine speed by combustion in the machine (11).

Description

[Technical field]

[0001] The present invention relates to a vehicle control device. [State of the art]

[0002] In recent years, a technology has been put into practical use for fuel efficiency by placing a vehicle in coasting mode, where a clutch device located between the engine and transmission is disengaged while driving (e.g., PTL 1). Coasting is a technique that directly utilizes the vehicle's kinetic energy for cruising, enabling improved fuel efficiency by extending the vehicle's travel distance.

[0003] On the other hand, there is the well-known regenerative driving, in which the vehicle's energy efficiency is improved by recovering the vehicle's kinetic energy as regenerative energy during deceleration. For example, in regenerative power generation, which converts kinetic energy into electrical energy, a motor is driven as an electric generator by rotation through the engine output shaft, or engine output shaft, etc., whereby the electrical energy generated by the power generation is stored in a battery.

[0004] The publications PTL2 to PTL5 disclose further state of the art. [Prior art literature][Patent literature] [PTL 1] JP 2016 – 22 772 A [PTL 2] DE 10 2016 124 262 A1 (Older application according to Section 3 (2) of the Patent Act) [PTL 3] DE 10 2017 202 971 A1 (Older application according to Section 3 (2) of the Patent Act) [PTL 4] JP 2016 - 130 054 A [PTL 5] US 2011 / 0 087 390 A1 [Summary of the invention]

[0005] To further improve fuel consumption, it is desirable to be able to switch appropriately between coasting and regenerative cruising, and to utilize each of these modes appropriately. It should be noted that when transitioning from coasting to regenerative cruising, the clutch device must be switched from the disengaged state to the engaged state. In this case, to reduce vibration and noise generated when the clutch device is engaged, engagement is preferably performed in a state where the engine speed has been increased, which results in energy consumption. Therefore, depending on the implementation of the cruising control, the energy consumed by increasing the engine speed may exceed the energy recovered by regenerative cruising.This is undesirable from the point of view of improving fuel consumption.

[0006] It is an object of the present invention to overcome the above-mentioned problem, the main objective being to provide a vehicle control device that enables appropriate switching between coasting and regenerative driving.

[0007] The above object is achieved by vehicle control devices according to claims 1, 4, 6 and 12, respectively.

[0008] When transitioning from coasting to regenerative driving, it is necessary to adjust the engine speed and engage the clutch device. Adjusting the engine speed involves energy consumption. Therefore, from an energy efficiency perspective, the energy consumed should be considered when assessing whether to transition to regenerative driving.

[0009] Regarding this point, with the foregoing configuration, when a braking operation is performed during coasting, the energy consumed when adjusting the engine speed and the energy recovered by regenerative running are estimated as the condition for implementing regeneration. The transition from coasting to regenerative running is then performed based on a comparison between the regeneration energy and the consumed energy. In this way, by switching to regenerative running with consideration of the consumed energy, it becomes possible to suppress, for example, transitions from coasting to regeneration, which are undesirable from the perspective of energy efficiency. Furthermore, the frequency of transitions from coasting to regenerative running can be reduced, and this leads to an improvement in drivability.Transitions from coasting to regenerative driving can thus be carried out appropriately.

[0010] It should be noted that a braking operation as a condition for implementing regeneration may be a driver's brake pedal operation or a deceleration decision made by a vehicle driving control unit (e.g., an automatic driving control unit). Furthermore, when a braking operation is performed during coasting, it is conceivable that the engine speed may be adjusted by an electric rotary machine, with the energy required to drive the electric rotary machine being estimated as consumed energy.

[0011] Preferably, a judging section is provided for judging whether the regeneration energy estimated by the estimating section is greater than the consumed energy, and if it is determined that the regeneration energy exceeds the consumed energy, the travel control section performs a transition from a coasting operation to a regenerative travel, whereas if it is determined that the regeneration energy is less than or equal to the consumed energy, the coasting operation is continued.

[0012] Since a transition from coasting to regenerative cruising is performed when it is judged that the regeneration energy exceeds the consumed energy, an amount of energy that exceeds the consumed energy can be recovered through regenerative cruising. Furthermore, since coasting is maintained if it is judged that the regeneration energy is less than or equal to the consumed energy, fuel consumption improvement can be achieved through coasting while suppressing transitions to regenerative cruising that are undesirable from an energy efficiency standpoint.

[0013] Preferably, when a braking operation is performed during the coasting operation as the condition for implementing regeneration, the estimating section estimates the consumed energy based on the speed of the vehicle.

[0014] Consumed energy is the energy required to rotate the engine's output shaft to a target speed and can be considered to be correlated with the vehicle speed. That is, when the vehicle speed is high, the target speed is higher, and the consumed energy increases accordingly. Since the consumed energy is estimated based on the vehicle speed, the consumed energy can be accurately estimated. As a result, transitions from coasting to regenerative driving can be performed appropriately.

[0015] Preferably, when a brake operation is performed during the coasting operation as the condition for implementing a regenerative travel, the estimation section estimates the regeneration energy based on the amount of a brake operation.

[0016] Regeneration energy can be considered to be correlated with the amount of braking. For example, if the amount of braking is large, indicating a driver demand for a high degree of deceleration, the amount of regeneration energy will be high. Given this, regeneration energy can be accurately estimated by using a configuration that estimates regeneration energy based on the amount of braking. Therefore, appropriate decisions can be made regarding transitions from coasting to regenerative driving.

[0017] A preferred embodiment includes a setting section for setting the continuation time of the regenerative travel when a braking operation is performed during a coasting operation, and the estimating section estimates the regeneration energy based on the amount of braking operation and the continuation time of the regenerative travel.

[0018] The regeneration energy can be considered to be correlated with the continuation time of regenerative travel. For example, the longer the continuation time of regenerative travel, the greater the amount of regeneration energy. Considering this point, since a continuation time of regenerative travel is set when a brake application is performed during coasting, and the regeneration energy is estimated based on the set continuation time of regenerative travel and the amount of brake application, the regeneration energy can be accurately estimated.

[0019] A preferred embodiment includes a storage section that stores continuation times for which regenerative travel was to be performed in the past, and the setting section sets the continuation time based on the history of the continuation times held in the storage section.

[0020] Since the continuation time of the regenerative drive is stored in the memory section when a regenerative drive is performed, and the continuation time is set based on the history of the continuation times stored in the memory section, it becomes possible to set the continuation time based on the regenerative drive trend for each specific vehicle. As a result, the continuation time can be set appropriately.

[0021] Preferably, continuation times are respectively stored for each of a plurality of predetermined running conditions of the vehicle, and when a brake operation is performed during coasting, the setting section acquires a continuation time history depending on the current running condition and sets a continuation time based on this history.

[0022] It is conceivable that the continuation times of regenerative travel may be affected by the driving conditions of the vehicle each time. For this reason, it is possible that the continuation times of regenerative travel may be increased in accordance with an increase in vehicle speed. In view of this, each time a brake operation is performed during coasting, a history of continuation times of regenerative travel is acquired that is in accordance with the driving condition of the vehicle, and coasting is adjusted based on the acquired history. In this case, by acquiring a history of continuation times of regenerative travel in accordance with the current driving condition, the coasting operation may be adjusted.A regenerative travel continuation time is set based on the current driving condition of the vehicle. The setting can be performed while considering conditions affecting the continuation time. As a result, the regenerative travel continuation time can be precisely set each time in accordance with the vehicle's driving condition.

[0023] Preferably, the regeneration device is a rotating electric machine that performs regenerative power generation by recovering kinetic energy of the vehicle as electric energy, and a correcting section is provided that corrects the estimation of the regeneration energy made by the estimation section with the correction made based on the state of a battery that stores the power recovered by the rotating electric machine.

[0024] With a configuration in which the energy or power generated by the regenerative power generation by the electric rotary machine is stored in the battery when transitioning from coasting to regenerative driving, only a limited amount of energy can be stored after the battery is close to a fully charged state. Therefore, the regeneration energy estimate is corrected based on the battery state. In this case, in addition to energy recovery, transitions to regenerative driving that are detrimental to energy efficiency can be appropriately suppressed by considering conditions on the energy storage side.

[0025] Preferably, the regeneration device is a rotary electric machine that performs regenerative power generation by recovering kinetic energy of the vehicle as electric energy, and a correction section is provided that corrects the estimation of the regeneration energy made by the estimation section with the correction made based on the state of the rotary electric machine.

[0026] With a configuration in which the electric power generated by regenerative power generation by a rotating electric machine is stored in a battery, even when transitioning from coasting to regenerative running, it may only be possible to recover a limited amount of energy if the internal temperature of the rotating electric machine is high. In view of this, the estimation of regeneration energy is corrected based on the state of the rotating electric machine. In this case, in addition to energy recovery, transitions to regenerative running that are detrimental from the perspective of energy efficiency can be appropriately suppressed by considering energy recovery conditions.

[0027] Preferably, a rotational force may be applied to the output shaft in the vehicle by a rotating machine, and when a transition is made from coasting to regenerative traveling, if the engine speed is less than a predetermined value, the traveling control section increases the engine speed by operating the rotating machine, while when the engine speed is greater than or equal to the predetermined value, the traveling control section increases the engine speed by combustion in the engine.

[0028] When the engine speed is increased, the combustion efficiency of the engine is low in a low-speed range, in which case, it can be considered that driving the engine by the rotary engine is more efficient than by in-engine combustion. On the other hand, the combustion efficiency of the engine is high within a high-speed range. Considering this, when transitioning from coasting to regenerative cruising, the rotary engine is operated to increase the engine speed if the speed is lower than the predetermined value, while when the engine speed is equal to or higher than the predetermined value, the speed is increased by in-engine combustion.Energy consumption can be reduced as much as possible when transitioning from coasting to regenerative driving, and energy efficiency can be improved.

[0029] A preferred embodiment is applied to the vehicle which can vary a gear ratio between the output shaft and the rotating shaft of a rotating machine which is the regeneration device, and is provided with a transmission control section which changes the gear ratio during a coasting operation to restrict a lowering of the engine speed.

[0030] With the above configuration, during coasting, the gear ratio between the engine output shaft and the rotor shaft of the rotating machine is changed to restrict the engine speed from decreasing. In this case, the inertia of the engine becomes large during coasting as a result of changing the gear ratio, and therefore, the time for which the output shaft continues to rotate may be extended. This makes it difficult for the engine speed to decrease after a transition to coasting is initiated. For example, if there is an intermediate transition from coasting to normal travel after coasting begins, the engine output shaft speed is maintained, so that the energy consumed during the transition can be reduced.

[0031] Preferably, the gear ratio is the ratio of the rotational speed of the rotating shaft of the lathe to the rotational speed of the output shaft, and when the condition for implementing a coasting operation is established, the transition control section increases the gear ratio above its previous value, while when the coasting operation is terminated, the transition control section reduces the gear ratio.

[0032] When traveling through engine combustion, the lathe rotates along with the engine, and this rotation causes sliding losses. Therefore, the reduction ratio is reduced when overrunning is canceled. In this case, after overrunning is canceled, the ratio of the lathe's rotation speed to the engine's rotation speed becomes smaller than the ratio during overrunning. As a result, sliding losses accompanying rotation of the lathe in the non-overrunning state can be reduced after the overrunning is canceled, and thus, traveling through engine combustion can be performed properly.

[0033] Preferably, the gear ratio is the ratio of the rotational speed of the rotating shaft of the rotating machine to the rotational speed of the output shaft, and when the condition for implementing a coasting operation is established, the transition control section increases the gear ratio over its previous value, and when the engine speed becomes equal to or higher than a predetermined speed as a setting of the engine speed, the transition control section reduces the gear ratio.

[0034] When the engine speed is increased by driving a lathe, it can be considered that a large torque value is not necessary if the engine speed is within a range equal to or greater than a predetermined speed. In view of this, with the above configuration, the gear ratio is reduced when the engine speed becomes equal to or higher than the predetermined speed. The gear ratio reduction enables a reduction in sliding losses that occur in the lathe before the pushing operation is canceled, as well as a reduction in the energy consumption associated with a transition to a non-pushing operation.

[0035] A preferred embodiment has, as the regeneration device, a rotary electric machine that performs regenerative power generation to recover kinetic energy of a vehicle as electric energy, the fourteenth means being applied to a vehicle by performing regenerative power generation by the rotary electric machine so as not to exceed a predetermined output, the fourteenth means having a setting section for setting a continuation time of the regenerative travel and a demand value.requested value of an output power requested by the regenerative travel when a braking operation is performed during the coasting operation, and having a permission section for allowing the output power of the regenerative power generation to be greater than the predetermined output power when the continuation time does not exceed a predetermined continuation time and the requested output power is equal to or greater than the predetermined output power.

[0036] Regenerative power generation by a rotating electric machine is performed at a predetermined output or less (i.e., the output is limited) due to heat considerations, etc., that accompany the power generation operation. Therefore, even if the amount of braking operation is large and the required output value of regenerative travel is high, for example, it may not be possible to recover sufficient regenerative energy due to the output limitation.

[0037] However, with the above configuration, when braking is performed during coasting, if the continuation time of regenerative running is short or equal to a predetermined value, and furthermore, the requested output is equal to or greater than a predetermined value, then regenerative power generation is permitted at an output higher than the predetermined output. For example, if the continuation time of regenerative running is very short and the requested output is high, then regenerative power generation is permitted at an output exceeding the predetermined output. That is, in this case, if the regenerative power generation time is very short, even if regenerative power generation is permitted,By performing power generation at an output equal to or greater than the allowable value, a temperature rise of the rotating electric machine can be limited. As a result, it is possible to efficiently recover regenerative energy in accordance with a required output value while preventing an excessive temperature rise of the rotating electric machine. [Brief description of the drawings]

[0038] The foregoing and other objects, features, and advantages of the present invention will become clear from the following detailed description made with reference to the accompanying drawings. In the drawings: Fig. Figure 1 is a configuration diagram showing the general outline of a vehicle control system. Fig. 2 is an explanatory diagram showing the general outlines of each of corresponding driving states. Fig. 3 is a timing diagram of a transition from a coasting mode to a regenerative driving mode. Fig. 4 is a flowchart showing driving control processing. Fig. Figure 5 is a correlation diagram showing a relationship between a SOC and a coefficient α. Fig. 6 is a flowchart showing travel control processing executed by a second embodiment. Fig. 7 is a flowchart of processing for estimating regeneration energy executed by a third embodiment. Fig. 8 is a correlation diagram showing a relationship between a vehicle speed, a road surface gradient, and a regeneration continuation time. Fig. 9 is a configuration diagram showing the general outline of a travel control section according to a fourth embodiment. Fig. 10 is a flowchart showing a processing sequence of gear ratio control according to the fourth embodiment. Fig. 11 is a timing chart of an operation during a coasting operation in the fourth embodiment. Fig. 12 is a flowchart showing control processing for regenerative power generation in a fifth embodiment. Fig. 13 is a correlation diagram showing a relationship between an amount of brake operation, a road surface gradient, and a requested value of regeneration output. (First embodiment)

[0039] An embodiment, which is a specific form of the present invention, will be described based on the drawings. The embodiment selectively implements normal travel, gravity travel (coasting travel), and regenerative travel of a vehicle equipped with an engine as a motive power source. Normal travel is a traveling state in which a clutch device is in a motive power transmission state, coasting is a traveling state in which the clutch device is in a state of interrupting transmission of motive power, and regenerative travel is a traveling state in which the clutch device is in a state of transmitting motive power and in which regeneration of kinetic energy of the vehicle is performed.

[0040] In a vehicle 10, which is in Fig. 1, an engine 11 is a multi-cylinder internal combustion engine driven by combustion of a fuel such as gasoline or light oil, and suitably provided with fuel injection valves, ignition devices, etc., as is well known. The engine 11 integrally includes an ISG 13 functioning as a generator and a motor (hereinafter also referred to as a "regenerating device" and a "rotating machine", respectively), with the rotating shaft of the ISG 13 drivingly connected to the engine output shaft (simply also referred to as an "output shaft") 12 through a belt or the like. The rotating shaft 14 of the ISG 13 can thereby be rotated by rotation of the engine output shaft 12, or the engine output shaft 12 can be rotated by the rotation of the rotating shaft 14 of the ISG 13.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 motive power output function of applying a rotational force to the engine output shaft 12. At the time of engine start-up, an initial rotation (start-up rotation) is applied to the engine 11 by the rotation of the ISG 13.

[0041] A battery 15 installed in the vehicle is electrically connected to the ISG 13 as a storage battery. Power can be supplied from the battery 15 to drive the ISG 13, and the battery 15 can be charged by power generated by the ISG 13. The power of the battery is also used to drive various electrical loads in the vehicle.

[0042] In addition to the ISG 13, auxiliary equipment 16, such as a water pump and a fuel pump, is installed on the vehicle 10 as devices driven by rotation of the engine output shaft 12. An air conditioning compressor may also be included as a driven device. The driven devices include devices directly connected to the engine output shaft 12, devices whose coupling to the engine output shaft 12 can be interrupted by actuation of a clutch device, as well as devices drivingly connected to the engine 11 through a belt, etc.

[0043] A transmission 18 is connected to the engine output shaft 12 via a clutch device (simply referred to as a "clutch") 17, which has a power transmission function. The clutch device 17 is, for example, a friction-type clutch provided with a set of clutch mechanisms including a disc (flywheel or the like) on the engine 11 side connected to the engine output shaft 12, and a disc (clutch disc or the like) connected to the transmission input shaft 21 on the transmission side. When the discs in the clutch device 17 come into contact with each other, a power transmission state (clutch engagement state) is established in which power is transmitted between the engine 11 and the transmission 18, whereas a power transmission interruption state (clutch disengagement state) is established.A clutch disengaged state (also known as a clutch-disengaged state) in which power transmission between the engine 11 and the transmission 18 is interrupted is established by separating the disks from each other. The clutch device 17 of the present embodiment is configured as an automatic clutch in which switching between the clutch engagement state and the clutch disengagement state is performed by an actuator such as a motor. The clutch device 17 may be disposed inside the transmission 18.

[0044] The transmission 18 is, for example, a continuously variable transmission (CVT) or a multi-speed transmission with a variety of shift speeds. The transmission 18 receives the power of the engine 11 as input from a transmission input shaft 21, changes the speed or rotational speed through the transmission gear ratio in accordance with the vehicle speed V and the engine speed, and outputs the power to the transmission output shaft 22.

[0045] Road wheels 27 are coupled to the transmission output shaft 22 via a differential gear 25 and a drive shaft 26 (vehicle drive shaft). Furthermore, the road wheels 27 are provided with a brake device 28 that applies braking force to each of the road wheels 27 by being driven by a hydraulic circuit, etc. (not shown in the drawings). The brake device 28 adjusts the braking force on each of the road wheels 27 in accordance with the pressure within a master cylinder (not shown in the drawings), which transmits the operating force of the brake pedal to the hydraulic fluid.

[0046] The system further 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 control devices installed in the vehicle. Each of the ECUs 31 and 32 is a known type of electronic control unit including a microcomputer, etc., and the ECUs 31 and 32 appropriately control the engine 11 and the transmission 18 based on detection results obtained from various sensors included in the system. The ECUs 31 and 32 are connected for mutual communication and can share control signals, data signals, etc. With the present embodiment, two ECUs 31 and 32 are provided, with the engine ECU 31 constituting a "vehicle control device." However, the present invention is not limited to this, and it would be equally possible for two or more ECUs to constitute a "vehicle control device."

[0047] The sensors include an accelerator sensor 41 that detects the amount of depression (accelerator operation amount) of an accelerator pedal functioning as an accelerator operation component, a brake sensor 42 that detects the amount of depression (brake operation amount) of a brake pedal functioning as a brake operation component, a vehicle speed sensor 43 that detects the vehicle speed V, a tilt angle sensor 44 that detects the gradient of the road surface on which the vehicle 10 is traveling, a rotation speed sensor 45 that detects the engine rotation speed, a battery sensor 46 that detects the state of the battery 15, etc. The detection signals from these sensors are sequentially input to the engine ECU 31.The system also includes load sensors (air flow sensor, intake pressure sensor) for detecting the engine load, a coolant temperature sensor, an outside air temperature sensor and an atmospheric pressure sensor, etc., but an illustration of these is omitted.

[0048] The engine ECU 31 performs various engine controls, such as controlling fuel injection amounts of fuel injectors and controlling ignition by ignition devices, based on detection results obtained from respective sensors, controlling engine starting, engine torque assist and power generation provided by the ISG 13, and controlling braking provided by the braking device 28. The transmission ECU 32 also performs engagement / disengagement control of the clutch device 17 and controlling the transmission 18 based on detection results obtained from respective sensors.

[0049] The vehicle 10 of the present embodiment has a function whereby, in a state where the vehicle 10 is traveling by being driven by the engine 11, coasting can be implemented with the clutch device 17 in the disengaged state. The vehicle 10 also has a function whereby regenerative traveling can be implemented with the clutch 17 in the engaged state for recovering kinetic energy. These functions are designed to improve fuel consumption.

[0050] Fig. 2 is an explanatory diagram showing outlines of each of the driving states of the vehicle 10. As shown in Fig. 2, the corresponding driving conditions are: (1) normal driving condition (2) Overrun or idle operating condition (3) regenerative driving state

[0051] The vehicle 10 transitions to each of the traveling states in accordance with a predetermined condition established as follows: The normal traveling state (1) is a state in which the vehicle 10 travels with the engine 11 operating and the clutch device 17 in the engaged state (specifically, this is a state determined in accordance with a gearshift operation position set by the driver). The coasting state (2) is a state in which the vehicle 10 travels with the engine 11 stopped and the clutch device 17 in the disengaged state.The regenerative running state (3) is a state in which the vehicle 10 is caused to run while regenerative power generation is performed by the ISG 13, with the engine 11 in operation (but without performing fuel injection) and the clutch device 17 in the engaged state.

[0052] A transition from the normal driving state (1) to the coasting driving state (2) and a transition from the coasting driving state (2) to the normal driving state (1) are performed in accordance with corresponding known conditions that are established. For example, while the vehicle is in the normal driving state (1), the engine ECU 31 will transition the vehicle 10 to the coasting driving state (2) if a predetermined coasting condition is established, which includes an accelerator condition and a braking condition.However, it would be equally possible for the predetermined condition for implementing coasting to include the conditions that the engine speed is stable at a value equal to or higher than a predetermined speed (for example, the idling speed or more), that the vehicle speed V is within a predetermined range (for example, 20 to 120 km / h), that the gradient (slope) of the road surface is within a predetermined range, etc. On the other hand, when in the coasting running state (2), the engine ECU 31 will change the vehicle 10 to the normal running state (1) if a predetermined coasting cancellation condition is established, which includes an accelerator condition and a braking condition. At this time, the coasting running state may be canceled if the predetermined condition for implementing coasting is no longer established.

[0053] Furthermore, a transition from the normal driving state (1) to the regenerative driving state (3) and a transition from the regenerative driving state (3) to the normal driving state (1) are carried out in accordance with predetermined known conditions that are established. For example, when in the normal driving state (1), the engine ECU 31 will change the vehicle 10 to the regenerative driving state (3) if a predetermined regeneration implementation condition is established, including a braking condition and a state of charge of the battery 15. Regenerative power generation is then carried out by the ISG 13, and kinetic energy is stored in the battery 15 as electric energy. On the other hand, when in the regenerative driving state, the engine ECU 31 will change the vehicle 10 to the normal driving state if a predetermined regeneration cancellation condition is established, including an accelerator condition.includes an accelerator state.

[0054] With the present embodiment, transitions from the coasting driving state (2) to the regenerative driving state (3) and from the regenerative driving state (3) to the coasting driving state (2) can be carried out.

[0055] The transition from the coasting running state (2) to the regenerative running state (3) will be described in detail. When transitioning from coasting running to regenerative running, it is necessary to engage the clutch device 17 that was in the disengaged state. In this case, in order to reduce the vibration and noise generated at the time of clutch engagement, it is desirable to adjust the rotational speed of the engine output shaft 12 in accordance with the rotational speed of the transmission input shaft 21 (that is, a rotational speed corresponding to the vehicle speed V) and then engage the clutch device 17 in this state. The present embodiment is configured such that starting of the engine 11 and increasing the engine speed are performed by driving the engine 11 by the ISG 13, and this driving by the ISG 13 involves energy consumption.Therefore, depending on the form of implementing regenerative driving, the energy (consumed energy) associated with increasing engine speed may be greater than the energy (regenerative energy) recovered through regenerative driving. Such a case is undesirable from the perspective of improving fuel efficiency.

[0056] The relationship between consumed energy and regeneration energy is described with reference to Fig. 3. It should be noted that in Fig. 3 Transitions from coasting to regenerative travel are shown as being performed based on a conventional coasting cancellation condition, whereby coasting travel is canceled if a predetermined braking operation is performed during coasting (for example, when the amount of braking operation becomes greater than a predetermined threshold). That is, in this case, a braking operation is included in the predetermined condition, thereby implementing regenerative travel during coasting. The braking operation may be an operation performed by the driver or may be a deceleration control operation (such as automatic braking) performed by a vehicle operation control unit.

[0057] In Fig. 3, coasting is implemented before time t11. In this state, the clutch is in the disengaged state, and the engine 11 is stopped. When a brake operation is performed at time t11, control is executed to transition to regenerative traveling. That is, the engine 11 is started by being driven by the ISG 13 with a rotational force applied to the engine output shaft 12. As a result, the engine speed increases. When an engine speed corresponding to a vehicle speed V is obtained (time t12), switching is performed from coasting to regenerative traveling. At this time, the clutch device is engaged, and regenerative power generation is performed by the ISG 13.The brake application is subsequently released during regenerative driving (time t13), the clutch device is disengaged, and regenerative driving is switched to coasting mode. Since operation of the engine 11 is stopped, the engine speed converges to zero during the transition to coasting mode.

[0058] When the amount of braking operation subsequently increases again, the engine 11 is started by the ISG 13 at time t14. The engine speed is then increased, and a transition from coasting to regenerative running is performed at time t15. Thereafter, when an accelerator operation is performed during regenerative running along with a release of the braking operation (time t16), a transition from regenerative running to normal running is performed.

[0059] In Fig. 3, the vehicle 10 is in the coasting driving state before a time t12 and from times t13 to t14, is in the regenerative driving state from times t13 to t14 and from times t15 to t16, and is in the normal driving state after time t16.

[0060] Here, it is assumed that the energy consumed in the transition to regenerative driving from time t12 to t13 is A1, the energy recovered during regenerative driving from time t12 to t13 is B1, the energy consumed in the transition to regenerative driving from time t15 to t16 is A2, and the energy recovered during regenerative driving from time t15 to t16 is B2. In this case, in the regenerative driving from t15 to t16, the regeneration energy B2 is greater than the consumed energy A2, so that an energy consumption improvement effect is achieved by the regenerative driving. On the other hand, in the regenerative driving from time t12 to t13, the consumed energy A1 exceeds the regeneration energy B1, so that the consumed energy cannot be recovered as regeneration energy.That is, the regenerative driving from time t12 to t13 causes energy loss due to the transition from coasting to regenerative driving, and this may be considered disadvantageous from the aspect of energy efficiency.

[0061] However, in the present embodiment, when a braking operation is performed as the predetermined condition for implementing regeneration during coasting, the regeneration energy that would be recovered by regenerative running is then estimated along with estimating consumed energy as the energy that would be consumed by adjusting (increasing) the engine speed. A transition from coasting to regenerative running can then be performed based on a comparison between the estimated consumed energy and regeneration energy. Specifically, if the regeneration energy is judged to be greater than the consumed energy, coasting is canceled and a transition to regenerative running is performed, whereas if the regeneration energy is judged to be less than the consumed energy, coasting is continued.That is, transitions from the coasting driving state to the regenerative driving state are made possible, but transitions to the regenerative driving state, which are disadvantageous from the point of view of energy efficiency, are suppressed.

[0062] This aspect of the embodiment is described using Fig. 3. At a time t11, when a brake operation is performed during coasting, the engine ECU 31 estimates the consumed energy A1 and the regenerative energy B1. Since it is then judged that the consumed energy A1 exceeds the regenerative energy B1, the coasting operation is maintained without a transition to regenerative travel. That is, in this case, the clutch device is left in the disengaged state from time t12 to t13, and no consumption of energy A1 or regeneration of energy B1 occurs. On the other hand, at time t14, it is estimated that the regenerative energy B2 is greater than the consumed energy A2, and therefore, at time t15, a transition from coasting to regenerative travel is performed. In this way, with this embodiment, as shown in Fig. 3, the regenerative travel from time points t12 to t13, which is disadvantageous from the viewpoint of fuel efficiency, is not implemented, whereas the advantageous regenerative travel from time points t15 to t16 is implemented.

[0063] If a brake operation is carried out during coasting, the engine ECU 31 estimates the consumed energy E rec and the regeneration energy E regen .

[0064] With this embodiment, the energy consumed is E rec the energy required to rotate the machine output shaft 12 using the ISG 13. In particular, the consumed energy E rec based on the sum of the required rotational energy and energy losses, which include friction losses, etc. More precisely, the consumed energy E rec estimated based on the following equation (1): [Math. 1] Erec=(12jωt2−12jω02)+∫0TstPlossdtEffmot×Effbatt_out

[0065] The definitions of the symbols in the preceding equation are briefly described. j expresses the inertia (moment of inertia) of the machine 11, ωt expresses the target speed of the machine 11, w0 expresses the current machine speed or actual machine speed, P loss expresses the output losses, T st expresses a target return time, Eff mot expresses the output efficiency of the ISG 13 when generating drive power, and Eff bat_out expresses the output efficiency of battery 15. The output losses are due to machine friction, etc., and can be calculated using known methods.

[0066] ωt is calculated based on the vehicle speed V. In this case, the higher the vehicle speed V, the larger the value of ωt becomes. However, since the engine is stopped during coasting, the value of ω0 can be considered zero in many cases. Furthermore, it can be considered that the numerical values ​​of other parameters do not vary much each time coasting is performed. Considering this, the consumed energy E rec be considered to be largely dependent on the vehicle speed V.

[0067] The engine ECU 31 also estimates the regeneration energy E regen . With this embodiment, the regeneration energy E regen an energy that can be recovered through regenerative driving. In particular, the regeneration energy E regen using a regeneration output power P regenestimated based on the amount of braking operation and a regeneration continuation time T gen is calculated, which is a predicted duration for which the regenerative drive will last. More specifically, the estimation is based on the following equation (2): [Math. 2] Eregen=Effgen×Effbatt_in∫0tgenPregendt

[0068] The definitions of the symbols in the preceding equation (2) are briefly described. Eff gen expresses the output efficiency of the ISG 13 in generating power and Eff bat_in expresses the input efficiency of the battery 15. The regeneration continuation time T gen is a value that is predetermined by an adjustment etc. for, for example, 10 seconds.

[0069] The engine ECU 31 controls a transition from a coasting operation to a regenerative drive by comparing the estimated values ​​of consumed energy E rec and a regeneration energy E regen .

[0070] A driving control processing executed by the vehicle driving control apparatus of the present embodiment will next be described using the flowchart of Fig. 4. This processing is repeatedly executed by the engine ECU 31 with a predetermined period of time.

[0071] In step S11 of Fig. 4, a decision is made as to whether the vehicle 10 is currently in the coasting running state with the clutch device disengaged. If there is a YES decision, then processing proceeds to step S12, while if there is a NO decision, then processing proceeds to step S21. In step S12, a decision is made as to whether the brake is engaged or not. This decision is made based, for example, on whether the amount of brake application detected by the brake sensor 42 is greater than zero. If there is a YES decision, then processing proceeds to step S13.

[0072] In step S13, the consumed energy E rec The energy consumed E rec is estimated, for example, based on equation (1) above. In step S14, the regeneration energy E regen The regeneration energy E regenis estimated, for example, based on equation (2) above. In step S15, a decision is made as to whether the regeneration energy E regen is greater than the consumed energy E rec . If there is a YES decision in step S15, that is, if the regeneration energy E regen greater than the energy consumed E rec is, then the coasting operation is canceled and a transition to regenerative driving is carried out (step S16). If there is a NO decision in step S15, that is, if the consumed energy E rec greater than the regeneration energy E regen then the overrun operation is continued (step S17).

[0073] On the other hand, if there is a NO decision in step S12, then processing proceeds to S18, where a decision is made as to whether the accelerator is in the on-state. The decision as to whether the accelerator is in the on-state is based, for example, on whether the accelerator operation amount detected by the accelerator sensor 41 is greater than zero. If there is a YES decision in step S18, the coasting operation is canceled and a transition to normal travel is executed (step S23). If there is a NO decision in step S18, this processing is immediately terminated. That is, the vehicle 10 remains in the coasting travel state.

[0074] In step S21, a decision is made as to whether the vehicle 10 is currently in the regenerative driving state. If the decision is YES, then processing proceeds to step S22, while if the decision is NO, this processing is immediately terminated. In step S22, a decision is made as to whether the accelerator is in the on state. If the decision is YES in step S22, that is, if the accelerator is operated during regenerative driving, the regenerative driving is canceled and a transition to normal driving is performed (step S23).

[0075] On the other hand, if there is a NO decision in step S22, then processing proceeds to step S24, where a decision is made as to whether the brake is in the off state. The decision as to whether the brake is in the off state is made based, for example, on whether the amount of brake application detected by the brake sensor 24 is zero. It should be noted that in step S24, other than judging the braking status, it would be possible to also judge, for example, whether the SOC of the battery 15 is greater than a predetermined value (for example, a value close to that of the fully charged state) or whether the vehicle speed V is greater than a predetermined value (for example, 30 km / h). If there is a YES decision in step S24, then a transition from regenerative traveling to coasting is executed (step S25).If a NO decision is made in step S24, this processing is terminated immediately. That is, the vehicle 10 remains in the regenerative driving state.

[0076] It should be noted that steps S13 and S14 correspond to an “estimation section,” step S15 corresponds to a “judgment section,” and steps S16 and S17 correspond to a “travel control section.”

[0077] As described above, a consumed energy E rec required when a transition from coasting to regenerative driving is performed, since the engine speed is increased (adjusted). On the other hand, when a transition from regenerative driving to coasting is performed, the consumed energy or consumption energy E recnot required. This means that the conditions required to execute a transition from coasting to regenerative driving and from regenerative driving to coasting are different. The energy consumed E rec is also required when transitioning from overrun to normal driving.

[0078] The following valuable effects can be obtained from the above-described embodiment.

[0079] With the foregoing embodiment, when a brake operation is performed as a condition for implementing a transition from coasting to regenerative running, the consumed energy E rec , which results from an adjustment of the machine speed, and the regeneration energy E regenrecovered through regenerative driving is estimated in each case. The transition from coasting to regenerative driving is then carried out based on a comparison between the consumed energy E rec and the regeneration energy E regen . In particular, if it is judged that the regeneration energy E regen is greater than the consumed energy E rec , the transition from coasting to regenerative driving is carried out because the energy that can be recovered through regenerative driving is greater than the energy consumed E rec However, if it is judged that the regeneration energy E regen less than the energy consumed E recis, coasting is continued, so that the effect of improved fuel efficiency through coasting can be achieved, and transitions to the regenerative driving state, which are detrimental from the perspective of energy efficiency, can be suppressed. Furthermore, the frequency of executing transitions from coasting to regenerative driving can be reduced, resulting in improved drivability. As a result, transitions between coasting and regenerative driving can be performed appropriately.

[0080] The energy consumed E rec is the energy required to rotate the engine output shaft 12 to a target engine speed and can be considered to be correlated with the vehicle speed V. That is, if the vehicle speed V is high, then the target engine speed is increased and the consumed energy E recwill be increased accordingly. Since a configuration is used in which the consumed energy E rec Based on the vehicle speed V, the consumed energy E rec can be accurately estimated. As a result, assessments regarding transitions from coasting to regenerative driving can be appropriately performed.

[0081] The regeneration energy E regen can be considered to be correlated with the amount of braking. For example, if the amount of braking is large, that is, if the driver requires a high degree of deceleration, then the regeneration energy E regen also large. In view of this, the configuration is such that the regeneration energy E regen is estimated based on the brake operation amount, the regeneration energy E regencan be accurately estimated. Therefore, assessments regarding transitions from coasting to regenerative driving can be carried out appropriately. (Modified form of the first embodiment)

[0082] With the foregoing embodiment, the engine 11 is stopped during coasting, but this can be changed. For example, during coasting, the engine speed can be maintained at an idle speed (e.g., 700 rpm) without stopping the engine 11. With such a configuration, the amount by which the engine speed is increased by driving by the ISG 13 is less than in the case of a configuration in which the engine 11 is stopped during coasting. Therefore, less consumed energy E recrequired during a transition from coasting to regenerative cruising. Therefore, since the engine speed is maintained at an idle speed, the response when coasting is canceled is improved compared to the case where the engine 11 is stopped during coasting.

[0083] Adjustment of the engine speed when a brake application is performed during coasting may be performed by means other than driving the ISG 13. For example, the engine speed may be adjusted by actuating or operating (combusting) the engine 11. In this case, the consumed energy E rec be estimated as the energy required for machine operation.

[0084] Furthermore, the engine speed can be increased by combined driving by the ISG 13 and combustion in the engine 11. In a low engine speed range, the combustion efficiency of the engine is low when the speed is increased, and therefore, in this case, driving by the ISG 13 to increase the engine speed is considered more efficient than combustion in the engine 11. On the other hand, in a high speed range, the combustion efficiency of the engine 11 is high. In view of this, a decision regarding whether to increase the engine speed by driving by the ISG 13 or by combustion in the engine 11 can be made in accordance with the current engine speed.For example, if the engine 11 is presently in a low-speed range, less than a predetermined value K, the speed could be increased by driving the ISG 13, whereas if the engine 11 is in a high-speed range equal to or greater than the predetermined value K, the speed would be increased by combustion in the engine 11. The predetermined value K may, for example, be the idle speed. In this case, for example, E would then be used. rec be reduced with a configuration where the energy E rec , which is consumed during a transition from coasting to regenerative driving, is estimated as energy consumed when the machine is driven by the ISG 13.

[0085] It should be noted that instead of increasing the engine speed by a combination of driving by the ISG 13 and combustion in the engine 11, it would be equally possible to use a combination of driving a starter motor (not shown in the drawings) and combustion in the engine 11.

[0086] Although the ISG 13 is used as a regeneration device in the foregoing embodiment, the regeneration device is not limited to this. For example, an alternator with only a power generation function or a flywheel can be used as a regeneration device. In the second case, kinetic energy of the vehicle 10 is stored in the flywheel as rotational energy. In this case, a starter motor can be used as a device for starting the engine 11. (Second embodiment)

[0087] With a second embodiment, the SOC is obtained as a parameter indicating the SOC of the battery 15 when the regeneration energy E regen is estimated, and the estimation of E regen is corrected based on the SOC.

[0088] Even if a transition from coasting to regenerative driving is possible, the regeneration energy E regen that can be recovered may be limited depending on the SOC of the battery 15. For example, in a situation where the SOC of the battery 15 is close to a full charge, the amount of power that the battery can store may become small, so that even if regenerative power generation is carried out, the regeneration energy E regen that can be recovered may be limited.

[0089] Therefore, if the regeneration energy E regenis estimated, the engine ECU 31 obtains the SOC of the battery 15 and corrects the estimated value of E regen based on the SOC. The corrected value of E regen is then compared with the consumed energy E rec used. When performing the correction, for example, if the SOC of the battery 15 is close to a full charge, the amount of energy that can be supplied to charge the battery 15 will be small and therefore the estimated regeneration energy E regen corrected by reducing it. However, the correction is not limited to any specific method and, for example, one method of correction is to reduce the estimated regeneration energy E regenby a coefficient α. In this case, there is a correlation relationship between values ​​of the SOC of the battery 15 that are within the usable range and values ​​of the coefficient α (greater than or equal to zero) less than or equal to 1), this relationship being Fig. 5 is illustrated. In Fig. 5, when the SOC is less than a predetermined value P, the coefficient α is 1. In such a case, the regeneration energy E regen not changed by applying the correction. On the other hand, if the SOC is equal to or greater than the predetermined value P, the coefficient α decreases as the SOC increases.

[0090] Fig. Fig. 6 is a flowchart of a processing sequence of a travel control processing applied to the second embodiment, which is repeatedly executed by the engine ECU 31 at a predetermined period, which is the processing of Fig. 4 replaced above. In Fig. 6 are processing steps that are the same as in Fig. 4, with the same step numbers as in Fig. 4 for simplicity of description. The processing differs from that of Fig. 4 by adding steps S31 and S32 and changing the processing contents of step S15.

[0091] In Fig. 6, when the vehicle 10 is in the coasting driving state and the brake is turned on (YES in steps S11 or S12), the consumed energy E rec estimated (step S13) and the regeneration energy E regenis estimated (step S14). In the next step S31, the engine ECU 31 obtains the SOC of the battery 15. In step S32, the estimated regeneration energy E regen based on the obtained SOC. In particular, the regeneration energy E regen based on the previous relationship between the SOC and the coefficient α.

[0092] Next, in step S15, a decision is made as to whether the corrected regeneration energy E regen greater than the energy consumed E rec If a YES decision is made in step S15, processing proceeds to step S16, where a transition to regenerative travel is performed. If a NO decision is made in step S15, processing proceeds to step S17, which continues coasting. It should be noted that step S32 corresponds to a "correction section."

[0093] With the preceding embodiment, the estimated regeneration energy E regen based on the SOC of the battery 15, so that conditions on the side of storing the regeneration energy E regen can be considered in addition to the balance between energy consumed E rec and regeneration energy E regen , and therefore transitions to regenerative driving, which are detrimental from the aspect of energy efficiency, can be appropriately suppressed. (Modified forms of the second embodiment)

[0094] With the foregoing second embodiment, a configuration is used in which the regeneration energy E regen based on the SOC of the battery 15, however, it would be equally possible to E regenbased on another parameter that is indicative of the condition of the battery 15. For example, the regeneration energy E regen based on the temperature of the battery 15.

[0095] Furthermore, it would be equally possible to use the regeneration energy E regen based on a parameter that is indicative of the state of the ISG 13. That is, in this case, conditions on the energy recovery side would be corrected by E regen be considered. For example, with a configuration where the regeneration energy E regen based on the temperature of the ISG 13, the temperature of the ISG 13 (such as the temperature of a switching element in the inverter section or the temperature of the stator of the motor unit) is corrected in step S31 of Fig. 6. In step S32, the regeneration energy E regenbased on this temperature. Even if a transition from coasting to regenerative driving is possible, it may be considered that regenerative energy generation is limited if the temperature of the ISG 13 exceeds a predetermined value. By considering this point in addition to the energy balance and correcting the regeneration energy E regen Based on the temperature of the ISG 13, the state on the energy recovery side can be considered and transitions to regenerative driving, which are disadvantageous from the point of view of energy efficiency, can be appropriately suppressed or kept low.

[0096] With the foregoing second embodiment, multiplying by a coefficient α is adopted as the method for correcting the regeneration energy E regenused, however, the present invention is not limited thereto. For example, it would be possible to calculate the amount of energy capable of being input to the battery based on the SOC and the capacity of the battery 15 and use it as the corrected value of the regeneration energy E regen the smaller of the amount of energy that is able to be input into the battery and the estimated amount of regeneration energy E regen to use.

[0097] With the foregoing second embodiment, a configuration is used in which the regeneration energy E regenbased on the SOC of the battery 15, however, it would be possible to use a configuration in which a transition from coasting to regenerative driving is prohibited if the SOC is equal to or greater than a predetermined value. With such a configuration, the predetermined value could be set, for example, as an SOC close to a full charge. Alternatively, a configuration could be used in which a transition from coasting to regenerative driving is prohibited based on a parameter indicative of the state of the battery 15, such as the temperature, etc., of the battery 15, or based on a parameter indicative of the state of the ISG 13.In the latter case, for example, if the temperature of the ISG 13 (such as the temperature of a switching element in the inverter section or the temperature of the stator of the motor unit) is equal to or greater than a predetermined value, a transition to regenerative driving would be prevented and the coasting operation would continue. (Third embodiment)

[0098] With the first embodiment, the regeneration continuation time is a predetermined value. However, since the tendency of vehicle travel will vary depending on the vehicle 10 and the driver, it is contemplated that the continuation times of regenerative travel will vary accordingly. Furthermore, since the driving condition will be different each time regenerative travel is implemented, it is contemplated that the continuation times of regenerative travel will change in accordance with the driving condition.

[0099] Therefore, with the third embodiment, when a brake operation is performed during coasting, a previous regenerative travel continuation time is obtained in accordance with the current traveling state of the vehicle 10, and the current regenerative travel continuation time (the regeneration continuation time T gen ) is set based on this previous continuation time. The regeneration energy E regen is then based on this set value of the regeneration continuation time T gen appreciated.

[0100] Each time a regenerative travel is performed, the engine ECU 31 stores the continuation time of this regenerative travel to form a history of continuation times of the regenerative travel with these continuation times stored in accordance with the respective traveling conditions and the history held in a memory, etc. in the engine ECU. A traveling condition includes, for example, the vehicle speed V, the road surface gradient, etc. It can be considered that the higher the vehicle speed V, the longer the continuation time of the regenerative travel becomes. Furthermore, it can be considered that the steeper the road gradient, the longer the continuation time of the regenerative travel becomes.

[0101] Fig. 7 is a diagram for describing a processing sequence for estimating the regeneration energy E regen with this embodiment, which in step S14 of Fig. 4 is executed. The processing is executed by the engine ECU 31 as a subroutine when step S14 of Fig. 4 is executed. That is, in Fig. 4, if the vehicle 10 is in the coasting running state and the brake is in the on state (YES in both of steps S11, S12), then processing proceeds to step S101 of Fig. 7 continues when the consumed energy E rec was estimated (step S13).

[0102] In step S101, the driving state or driving condition of the vehicle 10 is acquired. For example, the vehicle speed V is acquired based on a detected value from the vehicle speed sensor 43, and the gradient of the road surface is acquired based on a detected value from the inclination angle sensor 44. In step S102, a continuation time of a previously performed regenerative travel is acquired, that is, in accordance with the acquired driving condition. For example, a continuation time of a regenerative travel performed in the past at a vehicle speed V similar to the current value of the vehicle speed V can be acquired. The gradient of the road surface can also be taken into consideration. In step S103, the current regeneration continuation time T genbased on the achieved continuation time. In this case, for example, the regeneration continuation time T gen be set as the average of the continuation times of the past 10 implementations of a regenerative drive performed under driving conditions similar to the current driving conditions. The regeneration energy E regen is then estimated in step S104 based on the regeneration continuation time T gen that has been set, and processing returns to step S15 of Fig. 4. With this embodiment, step S103 corresponds to a "setting section" and step S104 corresponds to an "estimation section".

[0103] The regeneration energy E regenis considered to be correlated with the continuation time of regenerative driving. Considering this, with the previous configuration, when a brake application is performed during coasting or sailing, a regeneration continuation time T gen as the current continuation time and the regeneration energy E regen is based on this set value of T gen and estimated on the amount of brake application, which as a result the regeneration energy E regen can be accurately estimated.

[0104] Furthermore, since each time the regenerative travel has been implemented, the continuation time of this regenerative travel is stored, and the regeneration continuation time T gen based on a history of these stored continuation times, T genbe suitably set in accordance with the regenerative driving tendency of each specific vehicle 10. In addition, since the history of past continuation times of the regenerative driving is acquired in accordance with the driving conditions of the vehicle 10 and the regeneration continuation time T gen based on this history, T gen be set while considering conditions that affect the continuation time of regenerative driving. As a result, the regeneration continuation time T gen be suitably adjusted in accordance with the current driving condition each time regenerative driving is implemented, and this leads to increased estimation accuracy of the regeneration energy E regen . (Modified form of the third embodiment)

[0105] Although with the third embodiment, the regeneration continuation time T gen based on past regenerative travel continuation times stored in a memory or the like, this can be changed. For example, a regeneration continuation time T gen based on the driving condition of the vehicle 10 at that time. A correlation map, such as that of Fig. 8, for example, can be used with such a configuration. In Fig. 8, the higher the vehicle speed V, the longer the regeneration continuation time T gen and the steeper the gradient of the road, the longer T gen . Furthermore, information regarding traffic lights and traffic jams, etc. can be obtained by setting the regeneration continuation time T genbe used. In this case, for example, if there is a red traffic light in front of the vehicle 10 in the direction of travel, then the vehicle 10 has to stop, and therefore a short value of a regeneration continuation time T gen be set. (Fourth embodiment)

[0106] A fourth embodiment will be described next with a focus on different points from the first embodiment. Fig. 9 shows the general configuration of a travel control system in the fourth embodiment. The fourth embodiment relates to a vehicle control system having a transmission 51 between the engine output shaft 12 and the rotating shaft 14 of the ISG 13. The transmission 51 can change the gear ratio (rotational speed of the rotating shaft 14 / rotational speed of the engine output shaft 12) of the rotational power generated by the ISG 13. Denoting the rotational speed of the engine output shaft 12 as N1 and the rotational speed of the rotating shaft 14 as N2, the gear ratio is N2 / N1. The engine ECU 31 controls the gear ratio of the transmission 51 in accordance with conditions of the vehicle 10. Except for the inclusion of the transmission 51, the configuration is identical to that of Fig. 1.

[0107] With the first embodiment, a control was specifically described which is applied in a transition from the coasting driving state (2) to the regenerative driving state (3), which is shown in Fig. 2, however, with the fourth embodiment, a control applied in the coasting running state (2) will be specifically described. When the vehicle 10 transitions to coasting, the engine speed decreases as time passes because the engine 11 is stopped.

[0108] With the fourth embodiment, during coasting, the gear ratio of the transmission 51 is controlled to change toward a side that suppresses a change in the engine speed. Specifically, if the vehicle 10 is in the normal running state and the required condition for transitioning to the coasting running state is established, the gear ratio (rotational speed of the rotating shaft 14 / rotational speed of the engine output shaft 12) is made higher than its previous value. The vehicle 10 then transitions to coasting with the gear ratio in its increased state. If a transition is subsequently made from the coasting to normal running, the gear ratio is reduced. That is, the gear ratio is restored from its increased state to its original state.

[0109] In this case, if the gear ratio is increased before a transition to coasting is performed, kinetic energy is recovered by the ISG 13 during the resulting deceleration with the transition to coasting being performed after the energy is recovered. As a result, the inertia of the engine 11 is increased during coasting, so that a reduction in the engine speed during coasting is restricted, and therefore, the time for which the engine output shaft 12 continues to rotate during coasting can be extended. Due to this, if, for example, the continuation time of coasting is short, the consumed energy E rec, which accompanies the transition, can be reduced by ensuring rotation of the engine output shaft 12. It should be noted that, although the case of a transition from normal running to coasting has been described, the same applies to a transition from regenerative running to coasting.

[0110] A gear ratio control processing executed by the travel control device is described using the flowchart of Fig. 10. This processing is repeatedly executed by the engine ECU 31 at a predetermined period.

[0111] In step S41, a decision is made as to whether the vehicle 10 is currently in a non-coasting driving state (i.e., the normal driving state or the regenerative driving state). If there is a YES decision in step S41, processing proceeds to step S42, while if there is a NO decision, processing proceeds to step S46. In step S42, a decision is made as to whether the condition for implementing coasting is established. Regarding a transition from normal driving to coasting or sailing, for example, a decision is made as to whether the accelerator is off and the brake is off. If the decision in step S42 is YES, processing proceeds to step S43, while if the decision is NO, this processing then ends directly.

[0112] In step S43, the gear ratio of the transmission 51 is increased. Specifically, the gear ratio is changed such that the rotational speed of the rotating shaft 14 of the ISG 13 becomes higher than the rotational speed of the engine output shaft 12. In step S44, a decision is made as to whether the elapsed time since the gear ratio of the transmission 51 was changed has reached a predetermined time T. During the elapse of the predetermined time T, kinetic energy is recovered by the ISG 13 as rotational energy. If the predetermined time T has elapsed (S44: YES), the processing proceeds to step S45, where the clutch is disengaged (disconnected) and a transition to coasting is executed.

[0113] If the vehicle 10 transitions to the coasting running state and there is an affirmative decision in step S46, processing proceeds to step S47. In step S47, a decision is made as to whether the condition for canceling the coasting operation is established. For example, in the case of a transition to normal running, a decision is made as to whether the accelerator is in the on state. In the case of a transition to regenerative running, a decision is made as to whether the brake is on and the regeneration energy is large E regen the energy consumed E rec If there is a YES decision in step S47, processing proceeds to step S48 where driving of the engine by the ISG 13 begins.

[0114] In the next step S49, a decision is made as to whether this is the timing for executing the transition to normal running or regenerative running. Specifically, the engine ECU 31 judges whether the engine speed has risen to a value corresponding to the vehicle speed V by driving the ISG 13. If it is judged that it is the timing for executing the transition (step S49: YES), the processing proceeds to step S50. In step S50, the gear ratio of the transmission 51 is reduced. That is, the gear ratio is returned to its state before implementing the coasting running state. In step S51, the coasting running mode is canceled, and a transition to normal running or regenerative running is executed. On the other hand, if there is a NO decision in step S46 or step S47, this processing is directly terminated.It should be noted that steps S43 and S50 correspond to a “switching control section”.

[0115] Next is Fig. 11 a timing diagram showing the processing of Fig. 10 more specifically. A reference control (control that does not change the gear ratio of the transmission 51) and a control according to the present embodiment (control that changes the gear ratio of the transmission 51) are shown in FIG. Fig. 11. The reference control is shown by dashed lines and a control of the present embodiment is shown by solid lines in Fig. 11 shown. Fig. 11 illustrates a situation in which the vehicle 10 changes from the normal driving state to the coasting driving state and then changes from the coasting driving state to the regenerative driving state.

[0116] The reference control will be described first. In this control, the gear ratio of the transmission 51 is kept constant at a low level regardless of the running state. The normal running state is assumed to be established before time t21, and in this state, the clutch is on (engaged). When the condition for implementing coasting is then established at time t21, the clutch is turned off (disengaged), and a transition from normal running to coasting is executed. When the engine 11 is stopped, the engine speed decreases and reaches zero at time t23. Thereafter, when the condition for implementing regeneration is established at time t25, driving of the ISG 13 is started, and the engine speed is increased. After that, a transition from coasting to regenerative running is executed at time t25.With this reference control, it is necessary to increase the engine speed by ΔNE1 when transitioning to regenerative driving.

[0117] On the other hand, with control according to the present embodiment, the gear ratio of the transmission 51 is changed from low to high at a time t21 when the condition for implementing coasting is established. That is, in this case, the gear ratio is made higher than the gear ratio in the reference control. Kinetic energy is then recovered, and at a time t22 after the predetermined time T has elapsed, the clutch is turned off and a transition to coasting is executed. That is, in this case, the predetermined time T is a delay amount from the point at which the condition for implementing coasting is established until the coasting actually starts. Thereafter, the engine speed decreases, but the rate at which the speed decreases is lower than in the reference control.When the condition for executing regenerative travel is subsequently established at time t24, driving of the ISG 13 is started, and a transition from coasting to regenerative travel is then executed at time t25. With the control according to the present embodiment, it is necessary to increase the engine speed by ΔNE2 when transitioning to regenerative travel.

[0118] With the control according to the present embodiment, the amount by which the engine speed must be increased by driving the ISG 13 is smaller than that in the case of the reference control (ΔNE2 < ΔNE1). That is, by increasing the gear ratio in the coasting operation, the amount of energy E rec , which is consumed when a transition from a push operation to a non-push operation is carried out.

[0119] With the above configuration, in a coasting operation, the gear ratio is changed in a direction to suppress a reduction in the engine speed. Specifically, when the condition for implementing the coasting operation is established, the gear ratio is changed from LOW to HIGH, and a coasting operation is performed with the gear ratio at HIGH. By setting the gear ratio to HIGH, a reduction in the engine speed can be restricted compared to a case where a coasting operation is performed with the gear ratio at LOW. As a result, it is possible to extend a period for which the engine output shaft 12 rotates and to save the energy E rec to reduce the amount of energy consumed when transitioning from overrun to non-overrun mode.

[0120] When traveling by combustion in the engine 11, the ISG 13 rotates along with the engine, and sliding losses accompany this rotation. Considering this point, the gear ratio is changed from HIGH to LOW when coasting is canceled, that is, when a transition is made from coasting to non-coasting (i.e., a transition to normal cruising or regenerative cruising). In this case, the ratio of the rotational speed of the ISG 13 to the engine speed during non-coasting is lower than in the case of coasting. The sliding losses associated with the rotation of the ISG 13 in the non-coasting can thereby be reduced, and therefore, appropriate traveling by combustion in the engine 11 can be implemented.Furthermore, with a configuration in which a cooling fan is drivingly connected to the rotating shaft 14 of the ISG 13, the rotation noise of the cooling fan can be reduced due to the lowering of the rotational speed of the ISG 13. (Modified form of the fourth embodiment)

[0121] With the fourth embodiment described above, when coasting is canceled, the gear ratio is reduced (i.e., restored to its state before coasting was established), but the timing for reducing the gear ratio is not limited thereto. For example, it would be possible to reduce the gear ratio when the engine speed exceeds a predetermined threshold NE. th achieved during the period in which the engine speed is increased by driving the ISG 13 before a transition from coasting to regenerative driving is carried out.

[0122] In this case, for example, a step is provided which is executed if there is a NO decision in step S49 to judge whether the engine speed is equal to or greater than a threshold value NE th If the machine speed is equal to or greater than NE th is, then the processing proceeds to step S50, where the gear ratio is reduced. That is, the gear ratio is reduced before the coasting operation is canceled. On the other hand, if the engine speed is lower than the threshold value NE th the current processing is terminated. The threshold value NE thcan be set higher than a range of engine speed values ​​required to generate a sufficiently large torque value (switching torque) at the time of engine start-up. With this configuration, the sliding losses of the ISG 13 before the release of the overrun operation can be reduced by reducing the gear ratio at times when a large torque value is not required to start the engine, and therefore the consumed energy E rec associated with a transition to a non-overrun mode.

[0123] With the fourth embodiment, the gear 51 is provided between the engine output shaft 12 and the rotating shaft 14 of the ISG 13. However, the present invention is not limited to this if the gear ratio of the rotating power from the ISG 13 can be varied. For example, a capability of changing the gear ratio may be provided as an added function of the ISG 13.

[0124] With the fourth embodiment, for example, an AC machine with only a power generation function or a rotating machine (flywheel or the like) with no power generation function can be used instead of the ISG 13. With such a configuration, a gear is provided between the engine output shaft 12 and the rotating shaft of a device such as an AC machine, and during coasting, the gear ratio of this gear is changed in a direction to restrict a decrease in the engine speed. (Fifth embodiment)

[0125] When regenerative power generation is to be implemented, the engine ECU 31 transmits a power generation command to the ISG 13. At this time, the engine ECU 31 sets a requested regeneration output based on the amount of braking operation, the storage state of the battery 15, etc. The ISG 13 then performs regeneration based on the requested regeneration output. Electric power consistent with the state of the vehicle 10 is thereby obtained through regenerative power generation.

[0126] A restriction may be applied to the regeneration output from the ISG 13 to prevent the temperature of the ISG 13 from rising excessively due to the regenerative power generation operation. In this way, even if the requested regeneration output is high, the regeneration output is kept below a predetermined value W th by the output restriction, and in this case the regeneration energy E regen limited that is recovered. It should be noted that the limitation of renewable power generation is set by considering the continuation time of the regenerative run and can be set based on the assumption that the continuation time of a regenerative run will be approximately 30 seconds, for example.

[0127] With the present embodiment, the engine ECU 31 sets a regeneration continuation time T genand a requested regeneration output power when the condition for implementing regeneration is established. If the regeneration continuation time T gen is less than or equal to a predetermined threshold value TA and, in addition, the requested regeneration output power is equal to or higher than a predetermined threshold value WA, then regenerative power generation is permitted that exceeds the output value W thIn this case, the threshold TA is a judgment value for judging extremely short continuation times of regenerative driving and is set, for example, to 3 seconds. The threshold WA is set to correspond to the output limit of regenerative power generation. That is, in this case, regenerative power generation is implemented at a maximum output (which exceeds the output limit of regenerative power generation) for a very short time. In this way, the regenerative energy E regen be recovered efficiently.

[0128] The processing flow of the regenerative power generation executed by the engine ECU 31 will be explained with reference to the flowchart of Fig. 12. This processing is repeatedly executed by the engine ECU 31 at a predetermined time period.

[0129] In step S61, a decision is made as to whether the vehicle 10 is currently in a non-regenerative driving state (i.e., the normal driving state or coasting driving state). If the decision in step S61 is YES, the processing proceeds to step S62, while if there is a NO decision, this processing is terminated directly. In step S62, a decision is made as to whether the condition for implementing regeneration is established. For example, regarding a transition from coasting to regenerative driving, a decision is made as to whether the brake is on, while also calculating the regeneration energy E regen greater than the energy consumed E rec If the decision in step S62 is YES, the processing proceeds to step S63, while if there is a NO decision in step S62, this processing is then terminated directly.

[0130] In step S63, a regeneration continuation time T gen This can be done, for example, in the same way as for the processing of step S103 in Fig. 7. In the following step S64, a requested regeneration output is set. The requested regeneration output is set, for example, by applying the brake operation amount and the road surface gradient to the map shown in Fig. 13. In the map of Fig.13, the requested regeneration output is set to progressively higher values ​​as the brake application amount increases and as the road surface gradient becomes increasingly steeper. The road surface gradient can be obtained by the inclination angle sensor 44, by GPS information, or by a gyroscope sensor (not shown in the drawings), etc. It should be noted that steps S63 and S64 correspond to a "setting section."

[0131] In step S65, a decision is made as to whether the regeneration continuation time T gen is equal to or less than the threshold value TA and the requested regeneration output power is equal to or greater than the threshold value WA. If there is a NO decision in S65, the processing proceeds to step S66, where regenerative power generation is implemented at an output power that satisfies the output value W thThat is, in this case, regenerative power generation is performed within a normal range of output restriction. On the other hand, if there is a YES decision in step S65, then the processing proceeds to step S67, where regenerative power generation is permitted at an output power that does not exceed the value W th Specifically, the engine ECU 31 transmits a power generation control command to the ISG 13 to perform power generation at an output higher than the output value W th can be, and renewable power generation is then implemented. It should be noted that step S67 corresponds to a "permission section."

[0132] Furthermore, when regenerative power generation is to be performed by the ISG 13, excitation of the rotor of the motor unit of the ISG 13 is started based on a power generation control command from the engine ECU 31, and regenerative power generation is performed after the excitation is completed. It should be noted that some time is required to complete the excitation of the rotor, and the required time greatly affects the power generation efficiency when regenerative power generation is performed for a very short time.

[0133] Therefore, in order to efficiently perform regenerative power generation for a very short time, the engine ECU 31 causes the ISG 13 to initiate preparatory activities for regenerative power generation before establishing the condition for implementing regeneration. Specifically, when the amount of braking operation becomes equal to or greater than a threshold Th1, the engine ECU 31 causes the ISG 13 to initiate rotor excitation. In this configuration, the condition set for implementing regeneration is that the amount of braking operation becomes equal to or greater than a threshold Th2, where the magnitude relationship between the thresholds Th1 and Th2 is Th1 < Th2.Accordingly, when a brake operation is performed during a non-regenerative driving state, excitation of the rotor is started when the brake operation amount becomes equal to or greater than the threshold Th1, and regenerative power generation is started when the brake operation amount becomes equal to or greater than the threshold Th2. With such a configuration, since excitation of the rotor is started before a power generation control command is received from the engine ECU 31, regenerative power generation can be started quickly, and therefore the regeneration energy E can be saved. regen be efficiently recovered, even if renewable power generation is carried out for a very short period of time.

[0134] With the preceding configuration, if the condition to implement regeneration is established and the regeneration continuation time T genis less than or equal to the threshold value TA, while also the requested regeneration output power is equal to or greater than the threshold value WA, then regeneration operation is permitted at an output power that satisfies the output value W th For example, if the regeneration continuation time T gen is very short and the requested regeneration output power is large, then a regeneration power generation output greater than the output value W is enabled: +2 In this way, if the continuation time of renewable power generation is very short, a temperature increase of the ISG 13 can be suppressed even if the renewable power generation is performed at an output power that exceeds the output limit. This makes it possible to use the renewable energy E regenin accordance with a requested regeneration output while preventing excessive temperature rise of the ISG 13. (Modified form)

[0135] With the foregoing embodiments, an ISG 13 in which a generator and a motor are integrated is provided as the regeneration device, however, it would be equally possible for the regeneration device to be configured by appropriately providing an alternator (electric generator) and a motor that applies a rotational force to the engine output shaft 12.

Claims

[1] A vehicle control device applied to a vehicle (10) having an engine (11) as a travel drive source, a clutch device (17) arranged in a motive power transmission path coupled to an output shaft (12) of the engine (11), and a regeneration device (13) for recovering kinetic energy of the vehicle (10) via the output shaft (12), the vehicle control device comprising: a travel control section (S16, S17) that sets the clutch device (17) in a disengaged state for implementing a coasting operation by the vehicle (10) in response to a predetermined condition for implementing the coasting operation being established, and that performs a transition from the coasting operation to a regenerative travel using the regeneration device (13) by adjusting an engine speed and engaging the clutch device (17) in response to a predetermined condition for implementing regeneration being established during the coasting operation, and an estimation section (S13, S14) that, when a brake operation is performed as the condition for implementing regeneration during the coasting operation, estimates consumed energy as energy consumed by the adjustment of the engine speed and regeneration energy as energy recovered by the regenerative traveling; wherein a rotational force can be applied to the output shaft (12) of a rotary machine (13) in the vehicle (10), the travel control section (S16, S17) executes the transition from the coasting operation to the regenerative travel based on a comparison between the consumed energy and the regeneration energy, and if the engine speed is less than a predetermined value when the transition from the coasting operation to the regenerative travel is carried out, the travel control section (S16, S17) increases the engine speed by driving the output shaft (12) by the rotating machine (13), while if the engine speed is greater than or equal to the predetermined value, the travel control section (S16, S17) increases the engine speed by combustion in the engine (11). [2] The vehicle control device according to claim 1, wherein the regeneration device (13) is the rotating machine (13) applied to the vehicle (10) capable of varying a gear ratio between the output shaft (12) and a rotating shaft (14) of the rotating machine (13), and the vehicle control device has a gear ratio control section that changes the gear ratio to restrict a lowering of the engine speed during the coasting operation. [3] The vehicle control device according to claim 2, wherein the gear ratio is a ratio of a rotational speed of the rotating shaft (14) of the rotating machine (13) to the rotational speed of the output shaft (12), and when the predetermined condition for implementing the coasting operation is established, the gear ratio control section increases the gear ratio relative to the previous value thereof, and when the coasting operation is canceled, a gear ratio correcting section reduces the gear ratio. [4] A vehicle control device applied to a vehicle (10) having an engine (11) as a travel power source, a clutch device (17) arranged in a motive power transmission path coupled to an output shaft (12) of the engine (11), and a regeneration device (13) for recovering kinetic energy of the vehicle (10) via the output shaft (12), wherein the regeneration device (13) is a rotating machine (13) applied to the vehicle (10) capable of varying a gear ratio between the output shaft (12) and a rotating shaft (14) of the rotating machine (13), the vehicle control device comprising: a travel control section (S16, S17) that sets the clutch device (17) in a disengaged state for implementing a coasting operation by the vehicle (10) in response to a predetermined condition for implementing the coasting operation being established, and that performs a transition from the coasting operation to a regenerative travel using the regeneration device (13) by adjusting an engine speed and engaging the clutch device (17) in response to a predetermined condition for implementing regeneration being established during the coasting operation, an estimation section (S13, S14) that, when a brake operation is performed as the condition for implementing regeneration during coasting, estimates consumed energy as energy consumed by adjusting the engine speed and regenerative energy as energy recovered by the regenerative travel, and a gear ratio control section that changes the gear ratio to restrict a decrease in the engine speed during coasting; wherein the travel control section (S16, S17) executes the transition from the coasting operation to the regenerative travel based on a comparison between the consumed energy and the regeneration energy, the gear ratio is a ratio of a speed of the rotating shaft (14) of the lathe (13) to the speed of the output shaft (12), and when the predetermined condition for implementing the coasting operation is established, the gear ratio control section increases the gear ratio relative to the previous value thereof, and when the coasting operation is canceled, a gear ratio correcting section reduces the gear ratio. [5] The vehicle control device according to claim 2, wherein the gear ratio is a ratio of a rotational speed of the rotary shaft (14) of the rotary machine (13) to the rotational speed of the output shaft (12), and when the predetermined condition for implementing the coasting operation is established, the gear ratio control section increases the gear ratio relative to the previous value thereof, and when the engine speed becomes equal to or higher than the predetermined speed when the adjustment of the engine speed is performed, a gear ratio correction section reduces the gear ratio. [6] A vehicle control device applied to a vehicle (10) having an engine (11) as a travel power source, a clutch device (17) arranged in a motive power transmission path coupled to an output shaft (12) of the engine (11), and a regeneration device (13) for recovering kinetic energy of the vehicle (10) via the output shaft (12), wherein the regeneration device (13) is a rotating machine (13) applied to the vehicle (10) capable of varying a gear ratio between the output shaft (12) and a rotating shaft (14) of the rotating machine (13), the vehicle control device comprising: a travel control section (S16, S17) that sets the clutch device (17) in a disengaged state for implementing a coasting operation by the vehicle (10) in response to a predetermined condition for implementing the coasting operation being established, and that performs a transition from the coasting operation to a regenerative travel using the regeneration device (13) by adjusting an engine speed and engaging the clutch device (17) in response to a predetermined condition for implementing regeneration being established during the coasting operation, an estimation section (S13, S14) that, when a brake operation is performed as the condition for implementing regeneration during coasting, estimates consumed energy as energy consumed by adjusting the engine speed and regenerative energy as energy recovered by the regenerative travel, and a gear ratio control section that changes the gear ratio to restrict a decrease in the engine speed during coasting; wherein the travel control section (S16, S17) executes the transition from the coasting operation to the regenerative travel based on a comparison between the consumed energy and the regeneration energy, the gear ratio is a ratio of a speed of the rotating shaft (14) of the lathe (13) to the speed of the output shaft (12), and when the predetermined condition for implementing the coasting operation is established, the gear ratio control section increases the gear ratio relative to the previous value thereof, and when the engine speed becomes equal to or higher than the predetermined speed when the adjustment of the engine speed is performed, the gear ratio correction section reduces the gear ratio. [7] A vehicle control device according to any one of claims 1 to 6, wherein, when a braking operation is performed as the condition for implementing regeneration during coasting, the estimating section (S13, S14) estimates the regeneration energy based on an amount of the braking operation. [8] A vehicle control device according to claim 7, comprising a setting section for setting a continuation time of the regenerative travel when a braking operation is carried out as the condition for implementing regeneration during the coasting operation, wherein the estimation section (S13, S14) estimates the regeneration energy based on the amount of braking operation and the continuation time. [9] The vehicle control device according to claim 8, comprising a storage section for storing the continuation time of the regenerative travel when the regenerative travel is implemented, wherein the setting section sets the continuation time based on a history of continuation times stored by the storage section. [10] A vehicle control device according to claim 9, wherein the storage section stores the continuation times in accordance with corresponding ones of a plurality of running conditions of the vehicle (10), and when a braking operation is performed during the coasting operation, the setting section acquires the history in accordance with a running condition of the vehicle (10) and sets the continuation time based on the acquired history. [11] A vehicle control device according to any one of claims 1 to 7, wherein the regeneration device (13) is a rotary machine (13) for implementing regenerative power generation to recover kinetic energy of a vehicle (10) as electric energy, and the vehicle control device is applied to the vehicle (10) in which the regenerative power generation is carried out by the rotary electric machine (13) so as not to exceed a predetermined output power, and the vehicle control device comprises: a setting section for setting a continuation time for the regenerative travel and a requested output power requested by the regenerative travel when a brake operation is performed during the coasting operation, and a permission section for allowing the output power of the regenerative power generation to be greater than the predetermined output power when the continuation time does not exceed a predetermined continuation time and the requested output power is equal to or greater than the predetermined output power. [12] A vehicle control device applied to a vehicle (10) having an engine (11) as a travel power source, a clutch device (17) arranged in a motive power transmission path coupled to an output shaft (12) of the engine (11), and a regeneration device (13) for recovering kinetic energy of the vehicle (10) via the output shaft (12), wherein the regeneration device (13) is a rotating machine (13) for implementing regenerative power generation to recover kinetic energy of a vehicle (10) as electric energy, and the vehicle control device is applied to the vehicle (10) in which the regenerative power generation is carried out by the rotating electric machine (13) so as not to exceed a predetermined output power, the vehicle control device comprising: a travel control section (S16, S17) that sets the clutch device (17) in a disengaged state for implementing a coasting operation by the vehicle (10) in response to a predetermined condition for implementing the coasting operation being established, and that performs a transition from the coasting operation to a regenerative travel using the regeneration device (13) by adjusting an engine speed and engaging the clutch device (17) in response to a predetermined condition for implementing regeneration being established during the coasting operation, an estimation section (S13, S14) that, when a brake operation is performed as the condition for implementing regeneration during coasting, estimates consumed energy as energy consumed by adjusting the engine speed and regeneration energy as energy recovered by the regenerative travel, a setting section for setting a continuation time for the regenerative travel and a requested output power requested by the regenerative travel when a brake operation is performed during the coasting operation, and a permission section for allowing the output power of the regenerative power generation to be greater than the predetermined output power when the continuation time does not exceed a predetermined continuation time and the requested output power is equal to or greater than the predetermined output power; wherein the travel control section (S16, S17) executes the transition from the coasting operation to the regenerative travel based on a comparison between the consumed energy and the regenerative energy. [13] A vehicle control device according to any one of claims 1 to 12, comprising a judging section (S15) for judging whether, among the regeneration energy and the consumed energy estimated by the estimating section (S13, S14), the regeneration energy is greater than the consumed energy, wherein when it is judged that the regeneration energy is greater than the consumed energy, the travel control section (S16, S17) implements the transition from the coasting operation to the regenerative travel, while when it is judged that the regeneration energy is less than the consumed energy, the coasting operation is continued. [14] A vehicle control device according to any one of claims 1 to 13, wherein, when a braking operation is performed as the condition for implementing regeneration during coasting, the estimation section (S13, S14) estimates the consumed energy based on a speed of the vehicle (10). [15] The vehicle control device according to any one of claims 1 to 14, wherein the regeneration device (13) is a rotating electric machine (13) that performs regenerative power generation for recovering kinetic energy of the vehicle (10) as electric energy, and the vehicle control device includes a correcting section for correcting the regeneration energy estimated by the estimating section (S13, S14), the correction being based on a state of a storage battery that stores electric power generated by the rotating electric machine (13). [16] The vehicle control device according to any one of claims 1 to 14, wherein the regeneration device (13) is a rotating electric machine (13) that performs regenerative power generation for recovering kinetic energy of the vehicle (10) as electric energy, and the vehicle control device has a correcting section for correcting the regenerative energy estimated by the estimating section (S13, S14), the correction being based on a state of the rotating electric machine (13).

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