CN112752688B

CN112752688B - Vehicle control device

Info

Publication number: CN112752688B
Application number: CN201980065054.7A
Authority: CN
Inventors: 小仓健太郎; 长冈武史
Original assignee: Bosch Corp; Bosch Engineering KK
Current assignee: Bosch Corp; Bosch Engineering KK
Priority date: 2018-08-02
Filing date: 2019-06-18
Publication date: 2024-01-30
Anticipated expiration: 2039-06-18
Also published as: JP7223762B2; JPWO2020026621A1; WO2020026621A1; CN112752688A; DE112019003902T5

Abstract

Provided is a vehicle control device capable of smoothly replacing a braking force by regenerative braking with a braking force by hydraulic braking when a vehicle is decelerating. The vehicle control device (100) is provided with: a regenerative braking torque control unit (230) that reduces the target regenerative braking torque at a predetermined gradient when an engine rotational speed index related to the rotational speed of the engine (20) satisfies a predetermined condition while generating the regenerative braking torque in a fuel cut control in which fuel injection to the engine (20) is stopped; a hydraulic brake control unit (240) sets the difference between a requested braking torque requested by a driver of the vehicle (1) and a target regenerative braking torque as a target hydraulic braking torque.

Description

Vehicle control device

Technical Field

The present invention relates to a vehicle control device.

Background

A vehicle equipped with an engine as an internal combustion engine and a motor generator having a power generation function is known. When the vehicle is decelerating, the motor generator functions as a generator that converts kinetic energy input from the driving wheel side into electric energy, and also functions as a brake that transmits rotational resistance generated during the generation of electric energy as regenerative braking to the driving wheel side. In the field of vehicles equipped with motor generators, various techniques for controlling braking force of the vehicle have been proposed.

For example, patent document 1 discloses a brake system for a hybrid vehicle and an electric vehicle, and a control method thereof, which are described below: the hydraulic braking torque is changed in accordance with the regenerative braking torque that changes in accordance with the power generation amount of the motor generator, so that the braking force desired by the driver can be obtained.

Patent document 1 Japanese patent application laid-open No. 2008-056228.

In addition, when the vehicle is decelerating, fuel injection to the engine may be stopped due to an increase in fuel consumption. In addition, in a state where fuel injection is stopped, regenerative braking by the motor generator may be preferentially used for a braking request of the vehicle.

In a vehicle in which an engine and a motor generator are directly connected (cannot be disconnected), rotational resistance due to regenerative drive of the motor generator becomes a load on the engine, and therefore there is a possibility that an engine stall occurs when the engine speed is excessively reduced during deceleration.

In such a case, the following control is considered: the braking force by the regenerative braking is gradually reduced, and on the other hand, the reduction amount of the braking force by the regenerative braking is replaced with the braking force by the hydraulic braking.

As one of the control for replacing the braking force by the regenerative braking with the braking force by the hydraulic braking, a method of reducing the braking force by the regenerative braking according to a change in the engine speed is considered.

However, in the case of decelerating the vehicle, since the engine speed generally decreases with vertical fluctuations, the braking force by the regenerative braking decreases with vertical fluctuations in this method. On the other hand, since the braking force by the hydraulic brake is controlled by changing the hydraulic pressure flowing in the hydraulic circuit, a certain time lag occurs in the control of the braking force by the hydraulic brake.

Therefore, when such a control method is applied at the time of deceleration of the vehicle, there is a possibility that the braking force of the entire vehicle is unstable, causing vibration of the vehicle.

Disclosure of Invention

The present invention has been made in view of the above-described circumstances, and an object of the present invention is to provide a vehicle control device capable of smoothly replacing a braking force by a regenerative braking force with a braking force by a hydraulic braking force when a vehicle decelerates.

In order to solve the above-described problems, according to one aspect of the present invention, there is provided a vehicle control device mounted on a vehicle including an engine and a motor generator connected in series, and a hydraulic brake operated by hydraulic pressure, the vehicle control device controlling regenerative braking torque generated by the motor generator and hydraulic braking torque generated by the hydraulic brake, the vehicle control device including: a regenerative braking torque control unit that reduces a target regenerative braking torque at a predetermined gradient when an engine rotational speed index related to the rotational speed of an engine satisfies a predetermined condition in a state where the regenerative braking torque is generated during fuel cut control in which fuel injection to the engine is cut off; the hydraulic brake control unit sets a difference between a requested braking torque requested by a driver of the vehicle and a target regenerative braking torque as a target hydraulic braking torque.

According to the present invention as described above, it is possible to smoothly replace the braking force based on the regenerative braking with the braking force based on the hydraulic brake when the vehicle decelerates.

Drawings

Fig. 1 is a schematic diagram showing a configuration example of a vehicle to which a vehicle control device of a first embodiment of the present invention is applicable.

Fig. 2 is a block diagram showing a configuration example of the vehicle control device according to the embodiment.

Fig. 3 is an explanatory diagram showing an example of the operation of the vehicle control device of the comparative example.

Fig. 4 is an explanatory diagram showing an example of the operation of the vehicle control device according to this embodiment.

Fig. 5 is an explanatory diagram showing an example of the operation of the vehicle control device according to this embodiment.

Fig. 6 is a flowchart showing an example of the operation of the vehicle control device according to the embodiment.

Fig. 7 is a schematic diagram showing a configuration example of a vehicle to which the vehicle control device of the second embodiment of the present invention is applicable.

Fig. 8 is a block diagram showing a configuration example of the vehicle control device of the embodiment.

Fig. 9 is an explanatory diagram showing an example of the operation of the vehicle control device according to this embodiment.

Fig. 10 is an explanatory diagram showing an example of the operation of the vehicle control device according to this embodiment.

Fig. 11 is a flowchart showing an example of the operation of the vehicle control device according to the embodiment.

Detailed Description

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the present specification and the drawings, structural elements having substantially the same functional structures are denoted by the same reference numerals, and overlapping descriptions thereof are omitted.

< 1. First embodiment >

A vehicle control device according to a first embodiment of the present invention will be described.

[1-1. Example of the overall structure of the vehicle ]

First, an overall configuration example of a vehicle to which the vehicle control device of the present embodiment can be applied will be described with reference to fig. 1. Fig. 1 is a schematic diagram showing a vehicle 1 having a vehicle control device 100. Hereinafter, an overall configuration example of the vehicle 1 will be described separately into the power unit 10 and the control device 100.

(1-1-1. Power Unit)

As shown in fig. 1, a power unit 10 of a vehicle 1 includes an engine 20 as a power source. The power unit 10 includes a motor generator 30 that functions as a starter that starts when the engine 20 starts. The motor generator 30 also functions as a braking device when the vehicle is decelerating.

The engine 20 and the motor generator 30 are connected in series via, for example, a coupling. The power unit 10 includes a manual stepped shift mechanism 50 coupled to the motor generator 30 via a clutch mechanism 40. The stepped shift mechanism 50 is coupled to the driving wheels 60 via a differential mechanism or the like.

The motor generator 30 is connected to a battery 32 via a converter 34. The inverter 34 controls the motor generator 30 according to a control signal input from a control device 100 described later.

When the motor generator 30 is controlled as a starter, electric power is supplied from the battery 32 to the motor generator 30 via the converter 34. The motor generator 30 is started using the supplied electric power.

When motor generator 30 is controlled (regeneration control) as a brake device, motor generator 30 converts rotational energy input from drive wheels 60 into electric energy. The motor generator 30 transmits the rotational resistance generated at the time of the conversion to the drive wheels 60 as a regenerative braking torque.

The exciting current flowing to the rotor of the motor generator 30 is controlled by the converter 34, thereby controlling the braking force (regenerative braking torque) based on regenerative braking. The electric energy converted from the rotational energy is supplied as electric power from the motor generator 30 to the battery 32 via the converter 34.

The drive wheel 60 is provided with a hydraulic brake 62 that operates by hydraulic pressure. As the hydraulic brake 62, for example, a disc brake is used. The braking force (hydraulic braking torque) by the hydraulic brake 62 is controlled by controlling the hydraulic pressure supplied to the hydraulic brake 62.

The hydraulic pressure supplied to the hydraulic brake 62 is controlled by the hydraulic unit 70. The hydraulic unit 70 includes: an oil passage for supplying hydraulic pressure from a master cylinder, not shown, to the hydraulic brake 62, a pump for discharging brake fluid driven by a motor, and a control valve such as a solenoid valve for adjusting opening and closing of the oil passage. The pump and the control valve are controlled by a brake controller 120, which will be described later, to control the hydraulic pressure supplied to the hydraulic brake 62.

The clutch mechanism 40 switches the connection state of the motor generator 30 and the stepped shift mechanism 50, that is, switches the connection state of the engine 20 and the stepped shift mechanism 50. As the clutch mechanism 40, for example, a wet-type multiplate clutch is used. The clutch mechanism 40 is engaged or released by controlling the hydraulic pressure supplied to the clutch mechanism 40.

The clutch mechanism 40 is engaged, whereby the engine 20 and the stepped transmission mechanism 50 are coupled, and the drive wheel 60 is coupled to the engine 20 and the motor generator 30. On the other hand, when the clutch mechanism 40 is released, the connection between the engine 20 and the stepped transmission mechanism 50 is released, and the engine 20 and the motor generator 30 are disconnected from the drive wheels 60.

Further, although the above-described example has been described in which the engine 20 and the motor generator 30 are connected in series via the coupling, the engine 20 and the motor generator 30 may be connected via a belt and a pulley.

(1-1-2. Control device)

The overall structure of the control device 100 of the vehicle 1 is explained. As shown in fig. 1, the vehicle 1 includes various controllers including a microcomputer and the like for controlling the operation state of the power unit 10. As various controllers, an engine controller 110 and a brake controller 120 are provided.

These controllers are communicably connected to each other via one or more in-vehicle networks such as CAN (Controller Area Network) and LIN (Local Inter Net), and coordinate with each other to perform braking force replacement control.

Part or all of the respective controllers may be constituted by, for example, a microcomputer, a micro-processing unit, or the like. A part or all of the controllers may be constituted by an updatable component such as firmware, or may be a program module or the like executed in accordance with an instruction from a CPU or the like.

Each controller includes a storage device, not shown, which stores information such as programs executed by a microcomputer, parameters used for various operations, detection data, and operation results.

The memory device may be a memory element such as RAM (Random Access Memory) or ROM (Read Only Memory), or may be a memory device such as HDD (Hard Disk Drive), CD-ROM, or storage device.

The engine controller 110 is connected to a brake sensor 81, an acceleration sensor 83, a clutch sensor 85, and an engine speed sensor 87. The brake sensor 81 is connected to the brake controller 120.

The brake sensor 81 detects an operation amount of a brake pedal. The accelerator sensor 83 detects an operation amount of an accelerator pedal. The clutch sensor 85 detects an operation amount of the clutch pedal. The engine speed sensor 87 detects an engine speed as a rotational speed of the crankshaft.

The engine controller 110 outputs a control signal to a throttle, an injector, or the like of the engine 20, and controls engine torque, engine speed, and the like. During deceleration of the vehicle 1, the engine controller 110 stops fuel injection (hereinafter also referred to as "fuel cut control") while the engine 20 continues to rotate without stopping even if the fuel injection is stopped by the rotational force of the driving wheels 60.

Further, the engine controller 110 resumes the fuel injection when the engine speed decreases to approach a region where the engine stall can occur.

Further, the engine controller 110 outputs a control signal to the converter 34 connected to the motor generator 30, and controls the driving of the motor generator 30. When the vehicle 1 is decelerating, the engine controller 110 outputs a control signal to the converter 34 based on a control command from the brake controller 120, and controls the regenerative braking torque of the motor generator 30.

The brake controller 120 controls regenerative braking torque based on the motor generator 30 and hydraulic braking torque based on the hydraulic brake 62, and controls braking force of the vehicle 1.

The brake controller 120 sets a control target (target regenerative braking torque) of the motor generator 30 based on information transmitted from the respective sensors and the engine controller 110. The brake controller 120 outputs a control command related to the motor generator 30 to the engine controller 110 based on the set control target.

The brake controller 120 sets a difference obtained by subtracting the regenerative braking torque based on the motor generator 30 from the braking force (required braking torque) required for the vehicle 1 as a control target (target hydraulic braking torque) of the hydraulic brake 62. The brake controller 120 outputs a control signal to a pump and a control valve provided in the hydraulic unit 70 based on the control target, controls hydraulic braking torque, and the like.

In the present embodiment, when a braking operation is performed by a driver or the like in the fuel cut control, the brake controller 120 causes the motor generator 30 to generate a regenerative braking torque to decelerate the vehicle 1.

Further, when the engine speed decreases and the engine stall is likely to occur, the brake controller 120 performs braking force replacement control to gradually replace the regenerative braking torque with the hydraulic braking torque.

In the vehicle 1 in which the engine 20 and the motor generator 30 are connected in series, when the clutch mechanism 40 is in the engaged state, the driving wheels 60 are connected to the engine 20 and the motor generator 30.

In the case where the accelerator pedal is released and the required driving torque of the vehicle 1 becomes zero in this state, there is an operating region in which the rotational force of the driving wheels 60 is transmitted to the engine 20 so that the engine stall is not generated and the engine 20 can rotate even if the fuel is not injected to the engine 20.

In the operating region of the engine 20 as described above, the engine controller 110 performs fuel cut control to stop fuel injection to the engine 20 in order to increase fuel consumption of the vehicle 1.

When the driver operates the brake pedal during the fuel cut control, the brake controller 120 generates a regenerative braking torque. In the fuel cut control, the output torque from the engine 20 is zero, and the regenerative power generation with higher efficiency by the motor generator 30 can be performed. Therefore, the brake controller 120 generates braking force of the vehicle 1 by regenerative control of the motor generator 30 without using a hydraulic brake.

In the case where the vehicle 1 is further decelerated and the engine speed approaches the region where there is a possibility of engine stall, the engine controller 110 ends the fuel cut control and resumes the fuel injection. The fuel injection amount after restarting the fuel injection is controlled to an amount of a necessary minimum limit in order to keep the engine speed at a speed (for example, an idle speed) at which there is no possibility of the engine stalling.

Here, when the vehicle 1 is further decelerated and the regenerative braking torque does not become 0 when the engine speed reaches the idling speed, there is a possibility that the rotational resistance of the motor generator 30 becomes the load of the engine 20 and engine stall occurs.

Thus, the brake controller 120 replaces the braking torque of the vehicle 1 from the regenerative braking torque to the hydraulic braking torque before the engine speed reaches the idling speed. A specific example of the control device 100 capable of executing the braking force replacement control will be described below.

[1-2. Specific examples of control devices ]

A specific example of the vehicle control device 100 according to the present embodiment will be described. Fig. 2 is an explanatory diagram showing a functional configuration of a portion related to braking force replacement control in the control device 100 configured by the engine controller 110 and the brake controller 120 shown in fig. 1.

The control device 100 includes: a control start determination unit 210, a maximum regenerative braking torque setting unit 220, a regenerative braking torque control unit 230, and a hydraulic braking control unit 240.

The control device 100 obtains signals output from the brake sensor 81, the acceleration sensor 83, the clutch sensor 85, and the engine speed sensor 87. Various information shown in the acquired signals is stored in a storage device not shown.

(control start determination section)

For example, the engine controller 110 functions as a control start determination unit 210. The control start determination portion 210 determines whether to start the braking force replacement control based on information of various sensors.

Specifically, the control start determination unit 210 determines whether or not the engine speed, which is an index of the engine speed, acquired by the engine speed sensor 87 reaches the first speed at the time of deceleration of the vehicle. When the engine speed decreases to reach the first rotational speed, the control start determination unit 210 determines to start the braking force replacement control.

Here, when fuel injection is performed in the regeneration control of the motor generator 30, the output torque of the engine 20 is applied to the drive shaft to which the regenerative braking torque is applied, and fuel consumption is reduced. Therefore, it is preferable that the braking force replacement control is started before the restart of the fuel injection.

As the first rotational speed, an appropriate reference rotational speed higher than the idling rotational speed may be used. This is because, in the case of preventing the engine from stalling, the braking force replacement control may be started before the engine speed reaches the idle speed.

However, when the first rotational speed is too large as compared with the rotational speed at which fuel injection is resumed (fuel injection resuming rotational speed), the fuel consumption does not deteriorate, but a part of the regenerative braking torque is replaced with the hydraulic braking torque, and the regenerative efficiency is lowered. Therefore, it is preferable that the first rotational speed is a rotational speed obtained by adding an appropriate offset value to the fuel injection restart rotational speed, for example.

(maximum regenerative braking Torque setting section)

For example, the engine controller 110 functions as the maximum regenerative braking torque setting unit 220. When the control start determination unit 210 determines that the braking force replacement control is started, the maximum regenerative braking torque setting unit 220 sets the maximum regenerative braking torque that can be generated by the motor generator 30 as follows.

In the following description, the maximum regenerative braking torque that can be generated by the motor generator 30 is referred to as the maximum regenerative braking torque.

First, the maximum regenerative braking torque setting unit 220 sets the regenerative braking torque generated by the motor generator 30 to an initial value of the maximum regenerative braking torque at the time when the control start determination unit 210 determines that the braking force replacement control is started.

The maximum regenerative braking torque setting unit 220 monotonically decreases the maximum regenerative braking torque with a predetermined gradient over time. In this case, the maximum regenerative braking torque setting unit 220 may decrease the maximum regenerative braking torque so that the slope is linear.

The maximum regenerative braking torque setting unit 220 may increase the rate of decrease of the maximum regenerative braking torque so that the angle of the slope becomes larger when the maximum regenerative braking torque does not become 0 when the engine speed reaches the second speed.

That is, if the motor generator 30 is also rotationally driven after the engine rotational speed reaches the idling rotational speed, the rotational resistance of the motor generator 30 becomes the load of the engine 20, and there is a possibility that the engine stall may occur.

Therefore, if it is determined that the maximum regenerative braking torque does not become 0 before the engine speed reaches the idling speed, the slope for decreasing the maximum regenerative braking torque is preferably increased so that the maximum regenerative braking torque becomes 0 promptly. The second rotational speed may be, for example, a rotational speed obtained by adding an appropriate offset value to the idle rotational speed.

In addition, the maximum regenerative braking torque setting unit 220 may not change the slope even when the maximum regenerative braking torque does not become 0 when the engine speed reaches the second speed.

For example, when it is determined that the maximum regenerative braking torque is in the region close to 0 when the engine speed reaches the second speed and the maximum regenerative braking torque reaches 0 before the engine speed reaches the idle speed, the maximum regenerative braking torque setting unit 220 may not change the gradient.

(regenerative braking Torque control section)

For example, the engine controller 110 and the brake controller 120 function as a regenerative braking torque control unit 230. The regenerative braking torque control unit 230 controls the regenerative braking torque generated by the motor generator 30 based on the maximum regenerative braking torque set in the maximum regenerative braking torque setting unit 220 and information of various sensors. The regenerative braking torque control unit 230 controls the braking force of the entire vehicle 1 in coordination with the hydraulic braking control unit 240.

The regenerative braking torque control unit 230 calculates a required braking torque of the vehicle 1 based on, for example, the operation amount of the brake pedal obtained by the brake sensor 81. The regenerative braking torque control unit 230 compares the required braking torque with the maximum regenerative braking torque, and determines the smaller value as the target value (target regenerative braking torque) for the motor generator 30 to generate the regenerative braking torque. The regenerative braking torque control unit 230 controls the motor generator 30 via the converter 34 based on the determined regenerative braking torque. Thereby, the regenerative braking torque of the motor generator 30 is controlled.

(Hydraulic brake control section)

For example, the brake controller 120 functions as a hydraulic brake control unit 240. The hydraulic brake control portion 240 sets the difference in torque between the required braking torque and the target regenerative braking torque as the target hydraulic braking torque to be generated by the hydraulic brake 62.

In other words, the hydraulic brake control unit 240 sets the target hydraulic brake torque such that the total torque of the target regenerative brake torque and the torque of the target hydraulic brake torque coincides with the required brake torque.

The hydraulic brake control unit 240 controls a pump and a control valve provided in the hydraulic unit 70 based on the set target hydraulic brake torque. Thereby, the hydraulic braking torque of the hydraulic brake 62 is controlled.

[1-4. Working examples of control device ]

Thus, a configuration example of the control device 100 is described. An example of the operation of the control device 100 is described below.

(1-4-1. Overview)

First, with reference to fig. 3 to 5, an outline of a control method of the vehicle 1 by the control device 100 will be described. Fig. 3 is an explanatory diagram showing an example of the operation of the vehicle control device of the comparative example. Fig. 4 to 5 are explanatory diagrams showing operation examples of the vehicle control device of the present embodiment.

An example of the operation of the vehicle control device of the comparative example will be described with reference to fig. 3. The vehicle control device of the comparative example differs from the vehicle control device of the present embodiment in the following points: when the maximum regenerative braking torque tra is set, the engine speed is used as an input parameter.

At time t90, when the engine speed reaches the first speed na, the control device of the comparative example starts braking force replacement control. The first rotational speed na is a value obtained by adding an appropriate offset value to the fuel injection restart rotational speed nb.

After time t90, the control device of the comparative example sets the value of the maximum regenerative braking torque tra using the engine speed as an input parameter. For example, the maximum regenerative braking torque tra is set by multiplying the engine speed by a predetermined coefficient.

Here, in general, the engine speed is not linearly reduced but reduced with a slight up-and-down fluctuation at the time of deceleration of the vehicle 1. Therefore, the maximum regenerative braking torque tra set using the engine speed as an input parameter decreases with up-and-down fluctuation.

The control device of the comparative example compares the required braking torque tre calculated based on the operation amount of the brake pedal obtained by the brake sensor 81 and the like with the maximum regenerative braking torque tra, and sets the smaller value as the target regenerative braking torque.

When the maximum regenerative braking torque tra is smaller than the required braking torque tre, the target regenerative braking torque matches the maximum regenerative braking torque tra. In this case, the target regenerative braking torque decreases while varying up and down. As a result, the regenerative braking torque trb actually generated by the motor generator 30 decreases while varying up and down.

In the example shown in fig. 3, since the required braking torque tre is constant after time t90, when the target regenerative braking torque decreases with up-and-down fluctuation, the target hydraulic braking torque increases with up-and-down fluctuation.

Here, the regenerative braking torque trb actually generated by the motor generator 30 is generated by controlling the motor generator 30 through the inverter 34 in accordance with the target regenerative braking torque set by the regenerative braking torque control unit 230. That is, the regenerative braking torque trb is controlled by an electric signal.

On the other hand, the hydraulic brake torque trc actually generated by the hydraulic brake 62 is generated by the pump drive and control valve provided in the hydraulic unit 70 to open and close the oil passage in accordance with the target hydraulic brake torque set by the hydraulic brake control unit 240. That is, the hydraulic brake torque trc is physically controlled.

Therefore, the responsiveness of the hydraulic braking torque trc is poor as compared to the regenerative braking torque trb. That is, the total torque trd of the regenerative braking torque trb and the hydraulic braking torque trc may not coincide with the required braking torque tre and may fluctuate. Thus, the control device of the comparative example may cause vibration of the vehicle 1 at the time of replacement of braking force.

Next, an operation example of the vehicle control device according to the present embodiment will be described with reference to fig. 4. Fig. 4 shows an example of the operation of the control device 100 in the case where the vehicle 1 travels on a flat road.

At time t10, when the engine speed reaches the first speed na, the control start determination unit 210 determines that the braking force replacement control is started. The first rotational speed na is a value obtained by adding an appropriate offset rotational speed to the fuel injection restart rotational speed nb.

At time t10, the maximum regenerative braking torque setting unit 220 sets the regenerative braking torque trb at that time to an initial value of the maximum regenerative braking torque tra. The maximum regenerative braking torque setting unit 220 monotonically decreases the maximum regenerative braking torque with the lapse of time. In the example shown in fig. 4, the maximum regenerative braking torque decreases linearly.

In addition, as described above, the following performance of the hydraulic braking torque trc is poor compared to the regenerative braking torque trb. That is, when the regenerative braking torque trb decreases rapidly, the increase in the hydraulic braking torque trc may not follow.

Accordingly, it is preferable that the angle of the slope when the maximum regenerative braking torque tra is reduced be determined as an angle that the hydraulic brake 62 can follow with respect to a target hydraulic braking torque that increases in opposition to a target regenerative braking torque that decreases with a decrease in the maximum regenerative braking torque tra.

Also, the slope at which the maximum regenerative braking torque tra decreases may be determined as follows: during running of the vehicle 1 under predetermined conditions, the maximum regenerative braking torque tra becomes 0 before the engine speed reaches the idling speed nd. The predetermined condition may be, for example, a state in which the vehicle 1 is traveling on a flat road, a state in which the clutch mechanism 40 is engaged, or a state in which the accelerator pedal and the brake pedal are released.

For example, when the slope is linear, the slope angle may be set so that the rate of decrease of the maximum regenerative braking torque tra is-250N seed m/sec.

After time t10, the regenerative braking torque control unit 230 calculates the required braking torque tre based on the operation amount of the brake pedal or the like obtained by the brake sensor 81. The regenerative braking torque control unit 230 compares the required braking torque tre with the maximum regenerative braking torque tra, and sets the smaller value as the target regenerative braking torque.

In the example shown in fig. 4, after time t10, the maximum regenerative braking torque tra is smaller than the required braking torque tre. Therefore, the value of the target regenerative braking torque matches the value of the maximum regenerative braking torque tra, and decreases linearly with the passage of time. With this, the regenerative braking torque trb linearly decreases with the passage of time.

After time t10, the hydraulic brake control portion 240 sets the difference between the required braking torque tre and the target regenerative braking torque to the target hydraulic braking torque that causes the hydraulic brake 62 to generate.

In the example shown in fig. 4, the required braking torque tre is constant, and therefore, in the case where the target regenerative braking torque decreases linearly with the passage of time, the target hydraulic braking torque increases linearly with the passage of time. With this, the hydraulic brake torque trc linearly increases with the passage of time.

Thereafter, at a time t11 before a time t13 when the engine speed reaches the idling speed nd, the regenerative braking torque trb becomes 0, and the braking force replacement control ends.

As described above, in the present embodiment, the regenerative braking torque trb linearly decreases with the passage of time. Further, the hydraulic braking torque trc linearly increases with the lapse of time to compensate for the difference between the required braking torque tre and the regenerative braking torque trb.

Thereby, the total torque trd of the regenerative braking torque trb and the hydraulic braking torque trc becomes constant. That is, the vehicle control device 100 of the present embodiment can smoothly replace the braking torque of the vehicle 1 from the regenerative braking torque trb to the hydraulic braking torque at the time of deceleration of the vehicle.

In the example shown in fig. 4, the regenerative braking torque trb is 0 before time t13 when the engine speed reaches the idling speed nd. That is, the vehicle control device 100 of the present embodiment can improve the reliability of preventing the engine from stalling.

Next, with reference to fig. 5, a case will be described in which the regenerative braking torque may not become 0 until the engine speed reaches the idling speed. Fig. 5 shows an example of the operation of the control device 100 in the vehicle 1 traveling uphill. In the example of operation of the control device 100 shown in fig. 5, the engine speed is reduced more rapidly than in fig. 4.

In the example shown in fig. 5, the operation of the vehicle control device 100 before the time t12 when the engine speed reaches the second speed nc is the same as the operation shown in fig. 4.

In the example shown in fig. 5, at time t12 when the engine speed reaches the second speed nc, the maximum regenerative braking torque tra does not become 0. In such a situation, if the angle of the slope of the reduced maximum regenerative braking torque tra is not changed, the regenerative braking torque trb may not be 0 until time t13 when the engine speed reaches the idling speed nd.

At time t12, maximum regenerative braking torque setting unit 220 changes the slope so that the angle of the slope of reduced maximum regenerative braking torque tra increases.

In this case, the maximum regenerative braking torque setting unit 220 may change the slope so that the changed maximum regenerative braking torque tra linearly decreases with the lapse of time. For example, the slope angle may be set so that the rate of decrease of the maximum regenerative braking torque tra is-500N seed m/sec.

As described above, in the example shown in fig. 5, when there is a possibility that the regenerative braking torque does not become 0 before the engine speed reaches the idling speed, the angle of the slope of the reduced maximum regenerative braking torque tra increases in the middle.

Thereby, the regenerative braking torque trb becomes 0 before the time t13 when the engine speed reaches the idling speed nd. Thus, the vehicle control device 100 of the present embodiment can further improve the reliability of preventing the engine from stalling.

(1-4-2. Flow chart)

Next, a control method of the vehicle 1 by the control device 100 will be described with reference to fig. 6. Fig. 6 is a flowchart showing an example of the operation of the control device 100 of the vehicle 1 according to the present embodiment.

First, when the vehicle is decelerating, the control start determination unit 210 determines whether or not the engine speed acquired by the engine speed sensor 87 reaches the first speed (step S11).

When the engine speed does not reach the first speed (S11/no), the control start determination unit 210 determines that the braking force replacement control is not started, and repeats the determination of step S11 until the engine speed reaches the first speed.

On the other hand, when the engine speed reaches the first speed (S11/yes), the control start determination unit 210 determines to start the braking force replacement control.

When the control start determination unit 210 determines that the braking force replacement control is started, the maximum regenerative braking torque setting unit 220 decreases the maximum regenerative braking torque with the lapse of time as described above (step S13). The maximum regenerative braking torque setting unit 220 linearly decreases the maximum regenerative braking torque, for example.

Next, the regenerative braking torque control unit 230 sets a target regenerative braking torque based on the maximum regenerative braking torque and information of various sensors. Further, the hydraulic brake control portion 240 sets a target hydraulic brake torque based on the required brake torque and the target regenerative brake torque (step S15).

When the target regenerative braking torque is greater than the maximum regenerative braking torque, the target regenerative braking torque decreases linearly. Along with this, the target hydraulic brake torque obtained by subtracting the target regenerative brake torque from the required brake torque increases linearly.

Next, the maximum regenerative braking torque setting unit 220 determines whether the engine speed reaches the second speed (step S17).

When the engine speed does not reach the second speed (S17/no), the maximum regenerative braking torque setting unit 220 repeats the determination of step S17 until the engine speed reaches the second speed.

On the other hand, when the engine speed reaches the second speed (S17/yes), the maximum regenerative braking torque setting unit 220 determines whether or not the maximum regenerative braking torque becomes 0 (step S19).

When the maximum regenerative braking torque does not become 0 (S19/no), the maximum regenerative braking torque setting unit 220 increases the angle of the slope of the reduced maximum regenerative braking torque. Then, at the time when the regenerative braking torque becomes 0 and the replacement of the braking force ends, the vehicle control device 100 of the present embodiment ends the braking force replacement control.

On the other hand, when the maximum regenerative braking torque becomes 0 (S19/yes), the vehicle control device 100 of the present embodiment ends the braking force replacement control in this state.

In addition, in the braking force replacement control, the clutch mechanism 40 may be disconnected by the driver. In this case, the connection of the drive wheel 60 to the engine 20 is released, and therefore the regeneration control of the motor generator 30 is not performed.

Therefore, the regenerative braking torque quickly becomes zero, and the required braking torque of the vehicle 1 becomes the target hydraulic braking torque in this state. Thus, when the clutch mechanism 40 is disconnected by the driver during the braking force replacement control, the control device 100 can end the braking force replacement control at that time.

[1-5. Effect of control device ]

Next, effects of the control device 100 according to the present embodiment will be described.

According to the vehicle control device 100 of the present embodiment, in the braking force replacement control, the target regenerative braking torque monotonically decreases with the passage of time. Further, the target hydraulic brake torque is compensated for the difference between the requested brake torque and the target regenerative brake torque.

Thus, the vehicle control device 100 of the present embodiment can smoothly replace the braking torque of the vehicle from the regenerative braking torque to the hydraulic braking torque when the vehicle decelerates. As a result, the vibration of the vehicle 1 can be suppressed.

In the vehicle control device 100 according to the present embodiment, the target regenerative braking torque is linearly reduced with the passage of time. Therefore, the target hydraulic brake torque also increases relatively monotonically, and the effect of suppressing the vibration of the vehicle 1 can be improved.

Further, in the vehicle control device 100 of the present embodiment, the target regenerative braking torque is controlled to become 0 before the engine speed reaches the idling speed. Thus, the vehicle control device 100 of the present embodiment can improve the reliability of preventing the engine from stalling when the vehicle is decelerating.

In the vehicle control device 100 according to the present embodiment, when there is a possibility that the regenerative braking torque does not become 0 before the engine speed reaches the idling speed, the angle of the slope of the reduced maximum regenerative braking torque is changed so as to be increased in the middle.

Thereby, the reliability of the regenerative braking torque becoming 0 before the engine speed reaches the idling speed is further improved. Thus, the vehicle control device 100 of the present embodiment can further improve the reliability of preventing the engine from stalling.

< 2 > second embodiment

A vehicle control device according to a second embodiment of the present invention will be described. The vehicle control device of the present embodiment differs from the first embodiment in that the vehicle speed is used as an engine speed index for determining whether to start braking force replacement control. The following mainly describes differences from the vehicle control device of the first embodiment.

[2-1. Overall Structure of vehicle ]

First, an overall configuration example of a vehicle to which the vehicle control device of the present embodiment can be applied will be described with reference to fig. 7. Fig. 7 is a schematic diagram showing a vehicle 2 having a vehicle control device 300. Hereinafter, an overall configuration example of the vehicle 2 will be described, which is divided into the power unit 11 and the control device 300.

(2-1-1. Power Unit)

The power unit 11 of the vehicle 2 is provided with an automatic transmission having a continuously variable transmission mechanism 51 (hereinafter also referred to as "CVT") in place of the stepped transmission mechanism. The continuously variable transmission mechanism 51 has a primary pulley and a secondary pulley, and the primary pulley is coupled to the motor generator 30 via the clutch mechanism 41. The secondary pulley is coupled to the drive wheel 60 via a differential mechanism.

In the case of the continuously variable transmission mechanism 51, the engine speed can be kept constant by changing the ratio (pulley ratio) of the pulley diameter of the primary pulley to the pulley diameter of the secondary pulley at the time of deceleration of the vehicle 2. Therefore, in the vehicle 2 provided with the continuously variable transmission mechanism 51, control to maintain the engine speed at or above the fuel injection restart speed may be performed at the time of deceleration.

In this case, it is difficult to make a determination as to whether to start the braking force replacement control based on whether the engine speed is reduced to reach the first speed. Therefore, in the control device 300 of the present embodiment, the vehicle speed is used as an engine speed index for determining whether or not to start braking force replacement control.

In addition, at the time of deceleration of the vehicle 2, in the case where the engine speed cannot be kept constant by the continuously variable transmission mechanism 51 (i.e., in the case where the pulley ratio of the continuously variable transmission mechanism 51 becomes maximum), the engine speed decreases as the vehicle speed decreases.

The clutch mechanism 41 can switch the engaged state of the motor generator 30 and the continuously variable transmission mechanism 51. The clutch mechanism 41 corresponds to a lockup clutch of the torque converter. The configuration of the power unit 11 other than the continuously variable transmission mechanism 51 and the clutch mechanism 41 is the same as that of the vehicle 1 described above.

(2-1-2. Control device)

The control device 300 of the vehicle 2 includes an engine controller 310 and a brake controller 320. The engine controller 310 is connected to a brake sensor 81, an acceleration sensor 83, an engine rotation speed sensor 87, and a vehicle speed sensor 89.

The vehicle speed sensor 89 detects the vehicle speed of the vehicle 2. The engine controller 310 and the brake controller 320 correspond to the engine controller 110 and the brake controller 120 of the first embodiment.

The operation of the basic braking force replacement control by the control device 300 is the same as that of the first embodiment described above, except that it is determined whether or not the engine speed index at which the braking force replacement control is started is the vehicle speed.

However, in the vehicle 2 provided with the automatic transmission having the continuously variable transmission mechanism 51, there is a possibility that the vehicle speed is reduced and it is difficult to maintain the engine speed at or above the fuel injection restart speed. Therefore, the control device 300 according to the present embodiment is different from the first embodiment in that the replacement of the regenerative braking torque with the hydraulic braking torque is completed before the fuel injection to the engine 20 is restarted.

In the vehicle 2 provided with the automatic transmission having the continuously variable transmission mechanism 51, when the vehicle speed decreases and it is difficult to keep the engine rotational speed constant, the fuel injection is restarted in order to prevent the engine from stalling. At this time, there is a case where control is performed such that the engaged state of the clutch mechanism 41 is released so that the output torque of the engine 20 is not transmitted to the driving wheels 60. When the engaged state of the clutch mechanism 41 is released, a clutch release flag is generated by a transmission controller, not shown, for example.

In this case, since the regenerative efficiency using the rotational energy of the drive wheels 60 is reduced, the brake controller 320 quickly sets the regenerative braking torque to zero, and sets the required braking torque of the vehicle 2 in this state as the target hydraulic braking torque.

In addition, when the regenerative braking torque does not become 0 when the engaged state of the clutch mechanism 41 is released, the regenerative braking torque may be suddenly replaced with the hydraulic braking torque. As described above, the responsiveness and the follow-up performance of the hydraulic braking torque are poor as compared with the regenerative braking torque. Therefore, there is a possibility that the braking force of the vehicle 2 fluctuates and the drivability is affected.

Thus, in the present embodiment, the brake controller 320 controls to end the replacement from the regenerative braking torque to the hydraulic braking torque before the engine speed reaches the fuel injection restart speed. A specific example of the control device 300 capable of executing such braking force replacement control will be described below.

[2-3. Specific examples of control means ]

A specific example of the vehicle control device 300 of the present embodiment will be described. Fig. 8 is an explanatory diagram showing a functional configuration of a portion associated with braking force replacement control in the control device 300 configured by the engine controller 310 and the brake controller 320 shown in fig. 7.

The control device 300 includes a control start determination unit 410, a maximum regenerative braking torque setting unit 420, a regenerative braking torque control unit 430, and a hydraulic braking control unit 440. The control device 300 acquires signals output from the brake sensor 81, the acceleration sensor 83, the engine speed sensor 87, and the vehicle speed sensor 89, and information on the clutch release state.

The regenerative braking torque control unit 430 and the hydraulic braking control unit 440 are configured in the same manner as the regenerative braking torque control unit 230 and the hydraulic braking control unit 240 of the control device 100 according to the first embodiment.

(control start determination section)

For example, engine controller 310 functions as control start determination unit 410. In the present embodiment, at the time of deceleration of the vehicle, the control start determination unit 410 determines whether the vehicle speed acquired by the vehicle speed sensor 89 reaches a first speed set in advance. When the vehicle speed reaches the first speed, the control start determination unit 410 determines to start the braking force replacement control from the regenerative braking torque to the hydraulic braking torque.

As described above, in the present embodiment, the braking force replacement process is preferably ended before the restart of the fuel injection to the engine 20. In the case of the present embodiment in which the engine speed is maintained at or above the fuel injection restart speed by controlling the continuously variable transmission mechanism 51, the first speed may be the following speed: the speed at which an appropriate offset value is added to the vehicle speed at the time when the engine speed is not kept constant and the engine speed is reduced to reach the fuel injection restart speed (hereinafter referred to as "vehicle speed at the time of fuel injection restart") even by adjustment of the pulley ratio.

However, when the first speed is too high compared to the vehicle speed at the time of restarting the fuel injection, the fuel consumption is not deteriorated, but a part of the regenerative braking torque is replaced with the hydraulic braking torque, and the regenerative efficiency is lowered. Thus, the offset value is preferably determined in consideration of the regeneration efficiency.

(maximum regenerative braking Torque setting section)

For example, engine controller 310 functions as maximum regenerative braking torque setting unit 420. The maximum regenerative braking torque setting unit 420 sets the maximum regenerative braking torque in the same manner as the maximum regenerative braking torque setting unit 220 described above.

As described above, in the present embodiment, the replacement process of the braking force is preferably ended before the restart of the fuel injection. Therefore, when it is determined that the maximum regenerative braking torque does not become 0 until the vehicle speed reaches the vehicle speed at the time of restarting the fuel injection, the maximum regenerative braking torque setting unit 420 can increase the slope of reducing the maximum regenerative braking torque, and quickly make the maximum regenerative braking torque become 0.

For example, the maximum regenerative braking torque setting unit 420 may increase the rate of decrease of the maximum regenerative braking torque so that the angle of the slope increases when the maximum regenerative braking torque does not become 0 when the vehicle speed of the vehicle 2 reaches the second speed set in advance. The second speed may be, for example, a speed obtained by adding an appropriate offset value to the vehicle speed at the time of restarting the fuel injection.

[2-4. Working example of control device ]

(2-4-1. Overview)

An outline of a control method of the vehicle 2 by the control device 300 will be described with reference to fig. 9 to 10. Fig. 9 to 10 are explanatory diagrams showing operation examples of the vehicle control device of the present embodiment.

Fig. 9 is an operation example of the control device 300 in the case where the vehicle 2 travels on a flat road.

At time t30, when the vehicle speed reaches the first speed va, the control start determination unit 410 determines that the braking force replacement control from the regenerative braking torque trb to the hydraulic braking torque trc is started.

After time t30, the maximum regenerative braking torque setting unit 420 sets the regenerative braking torque trb at time t30 to an initial value of the maximum regenerative braking torque tra, and decreases the maximum regenerative braking torque tra with the lapse of time. In the example shown in fig. 9, the maximum regenerative braking torque decreases linearly.

The slope at which the maximum regenerative braking torque tra is reduced is preferably set within a range that can be followed by the target hydraulic braking torque hydraulic brake 62, as in the first embodiment.

The gradient when the maximum regenerative braking torque tra is reduced may be set as follows: during running of the vehicle 2 under the predetermined condition, the maximum regenerative braking torque tra becomes 0 before the engine speed reaches the fuel injection restart speed nb. The predetermined condition may be the same as that in the first embodiment.

After time t30, the value of the target regenerative braking torque matches the value of the maximum regenerative braking torque tra, and decreases linearly with the passage of time. Along with this, the target hydraulic brake torque increases linearly with the passage of time. Thus, the regenerative braking torque trb linearly decreases with the passage of time, and the hydraulic braking torque trc linearly increases with the passage of time.

Thereafter, at a time t31 before a time t33 when the engine speed reaches the fuel injection restart speed nb, the regenerative braking torque trb becomes 0, and the braking force replacement control ends.

Thereby, the total torque trd of the regenerative braking torque trb and the hydraulic braking torque trc becomes constant. That is, the vehicle control device 300 of the present embodiment can smoothly replace the braking torque of the vehicle 2 from the regenerative braking torque trb to the hydraulic braking torque trc at the time of deceleration of the vehicle.

In the example shown in fig. 9, the regenerative braking torque trb becomes 0 before the time t33 when the engine speed reaches the fuel injection restart speed nb. Thus, the vehicle control device 300 of the present embodiment can improve the reliability of preventing deterioration of fuel consumption and reduction of drivability.

Next, with reference to fig. 10, a case will be described in which the regenerative braking torque may not become 0 until the engine speed reaches the fuel injection restart speed. Fig. 10 shows an example of the operation of the control device 300 in the vehicle 2 traveling uphill. In the example of the operation of the control device 300 shown in fig. 10, the vehicle speed is reduced faster than in fig. 4. That is, the time for the engine speed to reach the fuel injection restart speed is shorter than that of fig. 4.

In the example shown in fig. 10, the operation of the vehicle control device 300 before the time t32 when the vehicle speed reaches the second speed vb is the same as the operation shown in fig. 9.

In the example shown in fig. 10, at time t32 when the vehicle speed of the vehicle 2 reaches the second speed vb, the maximum regenerative braking torque tra does not become 0. In such a situation, if the angle of the slope of the reduced maximum regenerative braking torque tra is not changed, the regenerative braking torque trb may not be 0 until time t33 when the engine speed reaches the fuel injection restart speed nb.

Therefore, at time t32, the maximum regenerative braking torque setting unit 420 increases the angle of the slope of the reduced maximum regenerative braking torque tra as described above.

As described above, in the example shown in fig. 10, when there is a possibility that the regenerative braking torque does not become 0 before the engine speed reaches the fuel injection restart speed, the angle of the slope that decreases the maximum regenerative braking torque tra is increased halfway.

Thus, the regenerative braking torque trb becomes 0 before the time t33 when the engine speed reaches the fuel injection restart speed nb. Thus, the vehicle control device 300 of the present embodiment can further improve the reliability of suppressing the deterioration of fuel consumption and the reduction of drivability.

(2-4-2. Flow chart)

Next, a control method of the vehicle 2 by the control device 300 will be described with reference to fig. 11. Fig. 11 is a flowchart showing an example of the operation of the vehicle control device according to the present embodiment.

When the vehicle is decelerating, the control start determination unit 410 determines whether the vehicle speed acquired by the vehicle speed sensor 89 reaches the first speed (step S31).

When the vehicle speed does not reach the first speed (S31/no), the control start determination unit 410 determines that the braking force replacement control is not started, and repeats the determination of step S31 until the vehicle speed reaches the first speed. On the other hand, when the vehicle speed reaches the first speed (S31/yes), the control start determination unit 410 determines to start the braking force replacement control.

When the control start determination unit 410 determines that the braking force replacement control is started, the maximum regenerative braking torque setting unit 420 decreases the maximum regenerative braking torque with the lapse of time as described above (step S33). The maximum regenerative braking torque setting unit 420 linearly decreases the maximum regenerative braking torque, for example.

Next, the regenerative braking torque control unit 430 sets a target regenerative braking torque based on the maximum regenerative braking torque that decreases with the passage of time and information of various sensors. Further, the hydraulic brake control portion 440 sets a target hydraulic brake torque based on the required brake torque and the target regenerative brake torque (step S35).

Next, the maximum regenerative braking torque setting unit 420 determines whether the vehicle speed reaches the second speed (step S37).

When the vehicle speed does not reach the second speed (S37/no), the maximum regenerative braking torque setting unit 420 repeats the determination of step S37 until the vehicle speed reaches the second speed. On the other hand, when the vehicle speed reaches the second speed (S37/yes), the maximum regenerative braking torque setting unit 420 determines whether or not the maximum regenerative braking torque becomes 0 (step S39).

When the maximum regenerative braking torque becomes 0 (S39/no), the maximum regenerative braking torque setting unit 420 increases the angle of the slope of the reduced maximum regenerative braking torque. Then, at the time when the regenerative braking torque becomes 0 and the replacement of the braking force ends, the vehicle control device 300 of the present embodiment ends the braking force replacement control.

On the other hand, when the maximum regenerative braking torque becomes 0 (S39/yes), the vehicle control device 300 of the present embodiment ends the braking force replacement control in this state.

In the vehicle 2 provided with the automatic transmission having the continuously variable transmission mechanism 51, the vehicle speed is used as the engine speed index for determining whether or not to start the braking force replacement control.

For example, in the vehicle 1 provided with the stepped shift mechanism 50 as in the first embodiment, the vehicle speed may be used as an engine speed index for determining whether or not to start the braking force replacement control.

[2-5. Effect of control device ]

Effects of the control device 300 of the present embodiment will be described.

In the vehicle control device 300 of the present embodiment, the vehicle speed is used as an engine speed index for determining whether or not to start braking force replacement control. Therefore, even for the vehicle 2 that performs control to keep the engine speed at or above the fuel injection restart speed, the braking force replacement control can be applied, and the same effects as those of the control device 100 of the first embodiment can be obtained.

In the vehicle control device 300 of the present embodiment, the regenerative braking torque is controlled to become 0 before the engine speed reaches the fuel injection restart speed. Thus, the vehicle control device 300 of the present embodiment can improve the reliability of suppressing the deterioration of fuel consumption and the reduction of drivability at the time of vehicle deceleration.

< 3. Summary >

As described above, in the vehicle control device according to the embodiment of the present invention, when the engine speed index related to the engine speed satisfies the predetermined condition in the state where the regenerative braking torque is generated during the fuel cut control, the target regenerative braking torque is reduced at the predetermined gradient, and the difference between the required braking torque and the target regenerative braking torque of the vehicle is set as the target hydraulic braking torque.

This allows the regenerative braking torque to be replaced with the hydraulic braking torque smoothly without decreasing with vertical fluctuation.

The preferred embodiments of the present invention have been described in detail above with reference to the drawings, but the present invention is not limited to the examples. It is obvious to those skilled in the art to which the present invention pertains that various modifications and corrections can be conceived within the scope of the technical idea described in the claims, and these are naturally considered to be within the technical scope of the present invention. It is needless to say that the mode of combining the above embodiments falls within the technical scope of the present invention.

For example, in the above embodiment, the vehicle control device is provided with two controllers, but the present invention is not limited to this example. Some or all of the functions of the controller may be integrated into one controller, or may be further divided into a plurality of controllers. Further, a higher level controller may be provided for controlling the two controllers in coordination with each other.

For example, in the above embodiment, the motor generator has a function as an actuator and a brake device, but the present invention is not limited to the related example. The motor generator may also have a function as a power source.

Reference numerals

1,2 … vehicle, 10, 11 … power unit, 20 … engine, 30 … motor generator, 32 … battery, 34 … converter, 40, 41 … clutch mechanism, 50 … stepped shift mechanism, 51 … continuously variable shift mechanism, 60 … drive wheel, 62 … hydraulic brake, 70 … hydraulic unit, 81 … brake sensor, 83 … acceleration sensor, 85 … clutch sensor, 87 … engine speed sensor, 89 … vehicle speed sensor, 100, 300 … control device, 110, 310 … engine controller, 120, 320 … brake controller, 210, 410 … control start determination portion, 220, 420 … maximum regenerative braking torque setting portion, 230, 430 … regenerative braking torque control portion, 240, 440 … hydraulic braking control portion.

Claims

1. A vehicle control device (100) mounted on a vehicle (1), the vehicle (1) comprising an engine (20) and a motor generator (30) connected in series, and a hydraulic brake (62) that is operated by hydraulic pressure, the vehicle control device (100) controlling a regenerative braking torque generated by the motor generator (30) and a hydraulic braking torque generated by the hydraulic brake (62),

The device is provided with:

a regenerative braking torque control unit (230) that reduces a target regenerative braking torque at a predetermined gradient when an engine rotational speed index related to the rotational speed of the engine (20) satisfies a predetermined condition while the regenerative braking torque is generated during fuel cut control in which fuel injection to the engine (20) is stopped;

a hydraulic brake control unit (240) that sets a difference between a requested braking torque requested by a driver of the vehicle (1) and the target regenerative braking torque as a target hydraulic braking torque,

when it is determined that the value of the target regenerative braking torque does not become 0 before the rotational speed of the engine (20) reaches the idling rotational speed, the regenerative braking torque control unit (230) increases the angle of the predetermined slope,

when the value of the target regenerative braking torque does not become 0 when the rotational speed of the engine (20) becomes a rotational speed obtained by adding a second offset rotational speed to an idle rotational speed, the regenerative braking torque control unit (230) increases the angle of the predetermined slope.

2. The vehicle control apparatus (100) according to claim 1, wherein,

The predetermined slope is set as follows: the value of the target regenerative braking torque becomes 0 before the rotational speed of the engine (20) reaches the idling rotational speed of the vehicle (1) while the vehicle (1) is traveling under predetermined conditions.

3. The vehicle control apparatus (100) according to claim 1, wherein,

the angle of the predetermined slope is set in the following range: the hydraulic brake is capable of following with respect to the target hydraulic brake torque.

4. The vehicle control apparatus (100) according to claim 1, wherein,

the engine speed index is the speed of the engine (20).

5. The vehicle control apparatus (100) according to claim 4, wherein,

the regenerative braking torque control unit (230) reduces the target regenerative braking torque at a predetermined gradient when the rotational speed of the engine (20) becomes a preset reference rotational speed.

6. The vehicle control apparatus (100) according to claim 5, wherein,

the reference rotational speed is a rotational speed obtained by adding a first offset rotational speed to a fuel injection restart rotational speed, which is a reference for restarting fuel injection to the engine (20).

7. The vehicle control apparatus (300) according to claim 1, wherein,

the predetermined slope is linear.

8. A vehicle control device (100) mounted on a vehicle (1), the vehicle (1) comprising an engine (20) and a motor generator (30) connected in series, and a hydraulic brake (62) that is operated by hydraulic pressure, the vehicle control device (100) controlling a regenerative braking torque generated by the motor generator (30) and a hydraulic braking torque generated by the hydraulic brake (62),

the device is provided with:

the engine speed index is the vehicle speed of the vehicle (2),

When the vehicle speed is a speed obtained by adding an appropriate offset value to the vehicle speed at the time when the rotational speed of the engine (20) reaches the fuel injection restart rotational speed, and the target regenerative braking torque value does not become 0, the regenerative braking torque control unit (430) increases the angle of the predetermined slope, and the fuel injection restart rotational speed is a reference for restarting the fuel injection to the engine (20).

9. The vehicle control apparatus (100) according to claim 8, wherein,

10. The vehicle control apparatus (100) according to claim 8, wherein,

11. The vehicle control apparatus (300) according to claim 8, wherein,

the regenerative braking torque control unit (430) reduces the target regenerative braking torque at a predetermined gradient when the vehicle speed reaches a first speed set in advance.

12. The vehicle control apparatus (300) according to claim 8, wherein,

the vehicle (2) has a continuously variable transmission mechanism (51),

the predetermined slope is set as follows: the value of the target regenerative braking torque becomes 0 before the rotational speed of the engine (20) reaches a fuel injection restart rotational speed, which is a reference for restarting fuel injection to the engine (20), during running of the vehicle (2) under a predetermined condition.

13. The vehicle control apparatus (300) according to claim 8, wherein,

the predetermined slope is linear.