JP6743329B2 - Control device for hybrid vehicle - Google Patents

Description

The present invention relates to a control device for a hybrid vehicle including an engine and a motor.

Conventionally, in Patent Document 1, a first motor generator provided between an engine and a transmission, a start clutch provided between the transmission and drive wheels, and a start clutch provided between the start clutch and the drive wheels. And a second motor generator provided. Then, when the required power generation torque exceeds the maximum power generation torque of the second motor generator, the starting clutch is engaged and both the first and second motor generators generate power.

JP, 2011-255700, A

However, when the power is generated only by the second motor/generator during deceleration, the engine rotation is changed when the starting clutch is engaged and the power is generated by both the first and second motor/generator due to the change in the required power generation torque. There was a problem that the number started up and the driver felt uncomfortable.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a control device for a hybrid vehicle that does not make a driver feel uncomfortable during deceleration.

In order to achieve the above object, in a hybrid vehicle control device of the present invention, a clutch that connects and disconnects an engine and a transmission, a first motor generator provided between the clutch and drive wheels, and the engine A second motor generator provided between the first motor generator and the clutch, and a control unit that controls the clutch, the first motor generator, and the second motor generator, the control unit including the first motor generator. A second mode in which the regenerative torque is generated only by itself, and a second mode in which the clutch is engaged to generate the regenerative torque in both the first motor generator and the second motor generator. During deceleration, when the regenerable energy corresponding to the required deceleration does not exceed the maximum regenerative energy of the first motor generator, the second mode is shifted to the first mode, and the deceleration in the first mode is being performed. in the even regeneratable energy exceeds the maximum regenerative energy, it was decided to prohibit the transition from the first mode to the second mode.

Therefore, even if the required deceleration changes during deceleration, the engine speed does not rise and the driver's discomfort can be avoided.

FIG. 1 is a system diagram of a vehicle including a hybrid vehicle control device according to a first embodiment. 6 is a flowchart showing a mode selection process of the first embodiment. 3 is a mode map of the first embodiment. 7 is a time chart for prohibiting the transition from the first mode to the second mode in the mode selection processing of the first embodiment. 7 is a time chart for prohibiting the transition from the first mode to the second mode in the mode selection processing of the first embodiment.

[Example 1]
FIG. 1 is a system diagram of a vehicle including a control device for a hybrid vehicle according to the first embodiment. The power train of the vehicle of the first embodiment is connected via an engine 1, which is an internal combustion engine, a torque converter 2 having a lockup clutch 3, a clutch 4, a belt type continuously variable transmission 7, and a final reduction mechanism. And a first motor generator 9 provided on the drive wheel side 8 of the clutch 4 and capable of exchanging torque between the belt type continuously variable transmission 7.

The engine 1 is connected to the crankshaft of the engine 1 via a belt and has a second motor generator 10 that functions as an alternator during traveling and, if necessary, exhibits a starter function and a torque assist function. In addition, the power train includes a mechanical oil pump 5 that supplies hydraulic pressure to the belt type continuously variable transmission 7 and various clutches while the engine is operating, and an electric oil pump 6 that supplies hydraulic pressure required when the engine is stopped. Have.

The power train can transmit and receive electric power to and from the first battery 11 via the DC-DC converter 13 and the first battery 11 having a rating of 48 V, which can transmit and receive electric power to and from the first motor generator 9 and the second motor generator 10. And a second battery 12 having a different rating of 12V. Hereinafter, the first battery 11 and the second battery 12 are collectively referred to as a battery module. The control unit 20 controls the charging state of the battery module and also controls the hydraulic pressures of the mechanical oil pump 5 and the electric oil pump 6, and controls the operating states of the first motor generator 9 and the second motor generator 10 and the clutch 4. The engagement state, the gear shift state of the belt type continuously variable transmission 7, and the engagement state of the lockup clutch 3 are controlled.

In the control unit 20, an accelerator pedal opening sensor 21 for detecting an accelerator pedal opening APO, a master cylinder pressure sensor 22 for detecting a master cylinder pressure Pmc which is a driver's braking intention, and a vehicle speed sensor 23 for detecting a vehicle speed VSP. And the like are input, and the traveling state is controlled based on various sensor signals.

In the normal acceleration state, the hybrid vehicle of the first embodiment engages the clutch 4 and runs with the engine 1 as the power source. Then, torque is applied to the power train from the first motor generator 9 and the second motor generator 10 as needed. The torque converter 2 releases or locks the lockup clutch 3 in a low vehicle speed region such as at the time of starting to amplify the torque, and engages the lockup clutch 3 in a higher vehicle speed side than the low vehicle speed region to improve efficiency. improves.

Further, the hybrid vehicle has three deceleration modes when transitioning from the acceleration state using the engine 1 as a power source to the deceleration state. In the first mode (hereinafter, also referred to as mode1), the clutch 4 is released and the regenerative torque is generated only by the first motor generator 9. In the first mode, the clutch 4 is released and the regeneration is performed only by the first motor-generator 9, so the engine 1 is not entrained during deceleration, and energy loss corresponding to engine friction can be avoided. However, when the regenerable energy REp corresponding to the deceleration state is equal to or greater than the first maximum regenerative energy RE1lim of the first motor generator 9, the energy of the difference (REp-RE1lim) cannot be recovered.

In the second mode (hereinafter also referred to as mode2), the clutch 4 is engaged and both the first motor generator 9 and the second motor generator 10 generate regenerative torque. In the second mode, the energy obtained by adding the first maximum regenerative energy RE1lim of the first motor generator 9 and the second maximum regenerative energy RE2lim of the second motor generator 10 can be recovered, so when the regenerable energy REp is large, High recovery efficiency can be obtained. However, since the clutch 4 is engaged and the engine 1 is rotated, energy loss corresponding to engine friction occurs.

In the third mode (hereinafter, also referred to as mode3), the regenerative torque is generated only by the first motor generator 9 with the clutch 4 engaged. The third mode is a state in which the clutch 4 is engaged and the engine 1 is rotated while the regeneration is performed only by the first motor generator 9. Although energy loss corresponding to engine friction occurs, the engine speed is maintained, so that even if the third mode is switched to the second mode, the engine sound does not give rise to a strange feeling.

The control unit 20 determines whether the operating point of the vehicle defined based on the vehicle speed VSP, the accelerator pedal opening APO and the master cylinder pressure Pmc is in the acceleration region or the deceleration region. When in the acceleration region, the first motor generator 9 and/or the second motor generator 10 apply torque to the power train. On the other hand, when it is in the deceleration region, one of the first to third modes is selected, and the first motor generator 9 and/or the second motor generator 10 receives the regenerative torque from the power train.

FIG. 2 is a flowchart showing the mode selection processing of the first embodiment. This flowchart is executed when the clutch 4 is engaged and the acceleration state using the engine 1 as the power source is changed to the deceleration state.
In step S1, it is determined whether or not the operating point of the vehicle is in the regenerative region. When it is in the regenerative region, the regenerative flag Freg is turned on and the process proceeds to step S2. Otherwise, this control flow ends.

FIG. 3 is a mode map of the first embodiment. This mode map is defined by a plane in which the horizontal axis represents vehicle speed VSP, the vertical side represents acceleration energy according to APO, and the negative side represents deceleration energy according to Pmc. The operating point is a point defined by the vehicle speed VSP and APO or Pmc. In the mode map of FIG. 3, a regenerable line representing regenerable energy REp set with a gradient according to the required braking torque is set. A shaded CS region in FIG. 3 represents a region in which the lockup clutch 3 is slip-engaged and decelerated only by the hydraulic brake (a region where regeneration is not performed). The other shaded areas surrounded by regenerative lines indicate areas where regenerative torque is generated only by the first and/or second motor generators 9 and 10, or by combined use with hydraulic brakes. In step S1, when the vehicle speed is equal to or higher than a predetermined vehicle speed outside the CS region and the master cylinder pressure Pmc is generated, it is determined that the vehicle is in the regeneration region.

In step S2, it is determined whether or not the vehicle is in the regenerative state. If the vehicle is in the regenerative state, the process proceeds to step S8, and otherwise the process proceeds to step S3. That is, it is determined whether or not the operating point first enters the regeneration area from the acceleration area.
In step S3, it is determined whether the regenerable energy Rep is larger than the first maximum regenerative energy RE1lim. If it is larger, the process proceeds to step S4 to set the second mode, otherwise the process proceeds to step S5.
In step S5, it is determined whether or not the vehicle speed VSP is higher than the first vehicle speed VSP1 that represents a region in which the first motor generator 9 alone can sufficiently regenerate the vehicle. Proceed to S8 to set the first mode.
In step S6, the mode determination timer Tim is counted up.
In step S7, it is determined whether or not the count-up value of the mode determination timer Tim exceeds a preset predetermined time Tim1, and when it exceeds, the process proceeds to step S8 to set the first mode. On the other hand, when the predetermined time Tim1 has not elapsed, the process proceeds to step S9 and the third mode is set. The predetermined time Tim1 is a time required for the deceleration to stabilize when a general driver decelerates, and is set in advance based on experiments and the like.

In step S10, it is determined whether or not the mode is the first mode. If the mode is the first mode, the process proceeds to step S11 to continue the first mode. Once the first mode is selected, the first mode is continuously selected during the current deceleration, and there is no transition to another mode.
In step S12, it is determined whether the regenerable energy Rep is larger than the first maximum regenerative energy RE1lim. If it is larger, the process proceeds to step S13 to set the second mode, otherwise the process proceeds to step S14 and the second The mode shifts to the first mode.

FIG. 4 is a time chart of transition from the second mode to the first mode in the mode selection processing of the first embodiment. At first, the engine 1 is in a steady running state with the power source as the power source, and the clutch 4 is engaged.
At time t1, when the driver releases the accelerator pedal and depresses the brake pedal, the regeneration flag Freg is turned on and the mode determination timer Tim starts counting up. At this time, since the predetermined time Tim1 has not yet elapsed, the third mode is set, the clutch 4 is engaged, and the regenerative torque is generated only by the first motor generator 9.

At time t2, as the master cylinder pressure Pmc increases, the gradient of the regenerable line increases, and when the regenerable energy REp exceeds the first maximum regenerative energy RE1lim, the third mode is switched to the second mode. .. As a result, the regenerative torque of the second motor generator 10 is generated in addition to the regenerative torque of the first motor generator 9, and energy is recovered as much as possible. At this time, since the clutch 4 is maintained in the engaged state, the engine speed does not fluctuate and the driver does not feel uncomfortable even when shifting to the second mode.

That is, the regenerable energy REp changes according to the generated deceleration, so the regenerable energy REp also changes until the deceleration stabilizes. Therefore, if the first mode is selected instead of the third mode when the operating point enters the region of the first mode, the clutch 4 is released and the engine 1 is stopped. Then, when the regenerable energy REp increases as the brake pedal is depressed, it is not possible to shift to the second mode, and sufficient energy cannot be recovered without giving a feeling of strangeness. On the other hand, in the first embodiment, since the third mode is selected when the operating point enters the regenerative region, it is possible to allow the transition to the second mode and recover sufficient energy without giving a sense of discomfort. it can.

At time t3, the master cylinder pressure Pmc enters a steady state and the gradient of the regenerable line stabilizes, and the regenerable energy REp gradually decreases as the vehicle speed VSP decreases.
At time t4, when the regenerable energy REp falls below the first maximum regenerative energy RE1lim, the mode shifts to the first mode. Therefore, the clutch 4 is released and the engine speed Ne becomes zero.
At time t5, when the operating point is within the CS range, the regeneration flag Freg is turned off, and the first mode ends. As a result, the regenerative torque by the first motor generator 9 becomes zero, and thereafter, the deceleration is continued by the hydraulic brake, and complete stop is made at time t6.

FIG. 5 is a time chart for prohibiting the transition from the first mode to the second mode in the mode selection processing of the first embodiment. At first, the engine 1 is in a steady running state with the power source as the power source, and the clutch 4 is engaged.
At time t1, when the driver releases the accelerator pedal and depresses the brake pedal, the regeneration flag Freg is turned on and the mode determination timer Tim starts counting up. At this time, since the predetermined time Tim1 has not yet elapsed, the third mode is set, the clutch 4 is engaged, and the regenerative torque is generated only by the first motor generator 9.

At time t2, the regenerable energy REp is less than the first maximum regenerative energy RE1lim, but when the count-up value of the mode determination timer Tim reaches the predetermined time Tim1, the third mode is switched to the first mode. As a result, the clutch 4 is released and the engine speed Ne becomes zero.

At time t3, when the regenerable energy REp exceeds the first maximum regenerative energy RE1lim, all the regenerable energy REp cannot be recovered only by the first motor generator 9. However, once the clutch 4 is disengaged and the engine speed Ne shifts from the state where the engine speed Ne becomes 0 to the second mode, the engine speed Ne rises, which gives the driver a feeling of strangeness. Therefore, at this time, the transition to the second mode is prohibited and the first mode is continued. Therefore, at time t4, even if the regenerable energy REp falls below the first maximum regenerative energy RE1lim, the first mode has already been set, and therefore no mode transition occurs.

At time t5, when the operating point is within the CS range, the regeneration flag Freg is turned off, and the first mode ends. As a result, the regenerative torque generated by the first motor generator 9 becomes zero, and thereafter, the hydraulic brake continues to decelerate and complete stop.

As described above, the working effects listed below are obtained in the embodiment.
(1) The clutch 4 that connects and disconnects the engine 1 and the belt type continuously variable transmission 7, the first motor generator 9 provided between the clutch 4 and the drive wheels 8, and the engine 1 and the clutch 4. A second motor generator 10 provided between and a control unit 20 for controlling the clutch 4, the first motor generator 9, and the second motor generator 10 are provided, and the control unit 20 releases the clutch 4 and Even when the regenerative energy RE1lim corresponding to the required deceleration exceeds the first maximum regenerative energy RE1lim of the first motor generator 9 during deceleration in the first mode in which the regenerative torque is generated only by the motor generator 9, the clutch 4 is activated. The transition to the second mode in which both the first motor generator 9 and the second motor generator 10 are engaged and regenerative torque is generated is prohibited.
Therefore, even if the required deceleration changes during deceleration, the engine speed does not rise and the driver's discomfort can be avoided.

(2) After starting deceleration with the clutch 4 engaged, the control unit 20 uses only the first motor generator 9 with the clutch 4 engaged before shifting to either the first mode or the second mode. Decelerates in the third mode that generates regenerative torque.
Therefore, it is possible to obtain an opportunity to shift to the second mode without changing the engine speed and improve energy recovery efficiency.

(3) The control unit 20 shifts to the second mode when the regenerable energy REp exceeds the first maximum regenerative energy RE1lim before the predetermined time Tim1 has elapsed from the start of the third mode, and otherwise. In case of, it shifts to the first mode.
That is, since the regenerable energy REp changes according to the deceleration, by determining the relationship with the first maximum regenerative energy RE1lim during the predetermined time Tim1 when the deceleration stabilizes, it is possible to determine the actual deceleration state. Energy recovery can be realized.

The present invention has been described above based on the first embodiment, but other configurations are also included in the present invention. For example, in the first embodiment, the configuration in which torque is transmitted and received to and from the first motor generator 9 on the primary pulley side has been described, but it may be on the secondary pulley side. Further, in the first embodiment, an example in which a belt type continuously variable transmission is provided as the transmission is shown, but a planetary gear type transmission or a parallel two-shaft type constantly meshing transmission may be used, and there is no particular limitation. Further, in the first embodiment, a fixed value obtained in advance by experiment is used as the predetermined time Tim1, but instead of the mode determination timer Tim, the time point when the rate of change of the deceleration becomes the predetermined value or less, that is, the deceleration is stable. The time point at which the third mode ends may be used as the end timing of the third mode.

1 Engine 2 Torque Converter 3 Lockup Clutch 4 Clutch 5 Mechanical Oil Pump 6 Electric Oil Pump 7 Belt Type Continuously Variable Transmission 8 Drive Wheel 9 First Motor Generator 10 Second Motor Generator 11 First Battery 12 Second Battery 20 control unit

Claims (3)

A clutch that connects and disconnects the engine and the transmission,
A first motor generator provided between the clutch and the drive wheels,
A second motor generator provided between the engine and the clutch;
A control unit for controlling the clutch, the first motor generator and the second motor generator;
Equipped with
The control unit has a first mode in which a regenerative torque is generated only by the first motor generator, and a second mode in which the clutch is engaged and a regenerative torque is generated by both the first motor generator and the second motor generator. When the regenerable energy corresponding to the required deceleration does not exceed the maximum regenerative energy of the first motor generator during deceleration in the second mode, the second mode is switched to the first mode. and, during deceleration in the first mode, the even regeneratable energy exceeds the maximum regenerative energy, of the hybrid vehicle and inhibits the transition from the first mode to the second mode Control device. The control device for a hybrid vehicle according to claim 1,
After starting deceleration with the clutch engaged, and before shifting to either the first mode or the second mode, the control unit regenerates only with the first motor generator with the clutch engaged. A control device for a hybrid vehicle, characterized in that deceleration is performed in a third mode in which torque is generated. The control device for a hybrid vehicle according to claim 2,
The control unit shifts to the second mode before the predetermined time has elapsed from the start of the third mode and when the regenerable energy exceeds the maximum regenerative energy, and otherwise, A control device for a hybrid vehicle, wherein the control device shifts to the first mode.

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