JP2000299903A - Controller for hybrid vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent fluctuation of rotation or torque when switching is made between series running and parallel running. SOLUTION: When a transition is made from series running mode to parallel running mode, command torque of an engine is increased by a specified value Tk at a time and the absolute value |Tdrv-Teg| of the difference between a driver request torque Tdrv and an engine drive torque Teg is checked against a set value Kt (S203-S205). If |Tdrv-Teg|<=Kt, the absolute value |Np-Nar| of the difference between the r.p.m. of a primary pulley Np and the actual r.p.m. of a motor A is checked against a set value Kn (S26). |Np-Nar|<=Kn, a command for locking a lockup clutch is delivered (S207). When a transition is made from parallel running mode to series running mode, engine torque is decreased gradually and a corresponding torque is outputted from a motor B. When the engine torque becomes 0, r.p.m. of the motor A matches the r.p.m. of the motor B and the lockup clutch is unlocked.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for a hybrid vehicle using an engine and two motors in combination.
More specifically, the present invention relates to a hybrid vehicle control device capable of switching between a series traveling mode and a parallel traveling mode according to traveling conditions.

[0002]

2. Description of the Related Art In recent years, hybrid vehicles that use both an engine and a motor have been developed for vehicles such as automobiles from the viewpoint of low pollution and resource saving. 2. Description of the Related Art A technology for improving the efficiency of power energy recovery and ensuring traveling performance by mounting two motors is often employed.

In such a hybrid vehicle, a power generation motor is driven by a mechanical output of an engine, and a driving mode is driven by a driving motor by a power generation output and a discharge output of a battery. There is known a vehicle that travels with a dynamic output and switches between a parallel traveling mode in which a difference in mechanical output of the engine with respect to a required output is compensated for by a motor in accordance with operating conditions.

For example, Japanese Patent Application Laid-Open No. H08-098322 discloses an engine, a generator driven by a mechanical output of the engine, a battery charged by a power output of the generator, and a battery driven by a discharge output of the battery. A series-parallel hybrid electric vehicle having a motor and a connection opening / closing means such as a clutch for opening / closing a mechanical connection between the generator and the motor is disclosed.

In the above-described series-parallel hybrid electric vehicle, parallel traveling is performed by engaging the clutch, and series traveling is performed by releasing the clutch. When the clutch is engaged, the number of revolutions of the generator and the number of motors are determined. By matching, the shock of clutch engagement is prevented.

[0006]

However, at the time of switching from series running to parallel running, simply closing the clutch by matching the rotation speed of the generator with the rotation speed of the motor, the engine side and the motor side cannot be connected. There is a possibility that torque fluctuations may occur due to the difference in output torque between the two, and when switching from parallel traveling to series traveling,
Simply releasing the clutch may cause fluctuations in rotation and torque.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and aims to prevent fluctuations in rotation and torque when switching between series running and parallel running, thereby realizing smooth running without deteriorating the driving feeling. It is an object of the present invention to provide a control device for a hybrid vehicle that can be used.

[0008]

In order to achieve the above object, an invention according to claim 1 is a first motor connected between an output shaft of an engine and a sun gear of a single pinion type planetary gear, and a first motor connected to the planetary gear. A second motor connected to the ring gear, a lock-up clutch for fastening and releasing the sun gear and the carrier of the planetary gear, and a second motor connected to the planetary gear carrier;
The drive mode of a hybrid vehicle having a power conversion mechanism for performing speed change and torque amplification between the planetary gears and the drive wheels in accordance with a gear ratio that can be switched in a plurality of steps or in a stepless manner, by releasing the lock-up clutch. A hybrid vehicle control device that switches between a series traveling mode in which the vehicle travels and a parallel traveling mode in which the lock-up clutch is engaged to travel, wherein the drive of the engine is performed when shifting from the series traveling mode to the parallel traveling mode. After gradually increasing the torque to shift to the driving torque in the parallel traveling mode, the first
Means for making the rotation speed of the motor substantially equal to the rotation speed of the input shaft of the power conversion mechanism and engaging the lock-up clutch.

Further, according to the invention described in claim 2, according to claim 1,
In the invention described above, at the time of transition from the parallel traveling mode to the series traveling mode, the driving torque of the engine is gradually reduced, and the driving torque of the second motor is gradually reduced by the reduced amount of the driving torque of the engine. And the driving torque of the engine becomes substantially zero.
Means for releasing the lock-up clutch by causing the rotation speed of the first motor to substantially match the rotation speed of the second motor when.

That is, according to the first aspect of the present invention, the first motor connected between the output shaft of the engine and the sun gear of the single pinion type planetary gear, the second motor connected to the ring gear of the planetary gear, and the planetary gear A lock-up clutch for engaging and disengaging the sun gear and the carrier, and connected to the planetary gear carrier to perform gear shifting and torque amplification between the planetary gears and the drive wheels according to a gear ratio that can be switched in a plurality of stages or steplessly. In a hybrid vehicle equipped with a power conversion mechanism, when shifting from a series traveling mode in which the lock-up clutch is released and traveling to a parallel traveling mode in which the lock-up clutch is engaged to travel, the drive torque of the engine is gradually increased. The driving torque in the parallel running mode The rotational speed of the first motor on which is line substantially matched to the input shaft rotation speed of the power conversion mechanism, is fastened to the lock-up clutch.

According to the second aspect of the invention, when shifting from the series traveling mode in which the lock-up clutch is released to the parallel traveling mode in which the lock-up clutch is engaged to travel, the drive torque of the engine is gradually increased. After shifting to the driving torque in the parallel running mode, the rotation speed of the first motor is made substantially coincident with the input shaft rotation speed of the power conversion mechanism to engage the lock-up clutch. When shifting to the series driving mode, the driving torque of the engine is gradually reduced, and the driving torque of the second motor is gradually increased by the reduced amount of the driving torque of the engine. Lock-up by substantially matching the rotation speed of the first motor with the rotation speed of the second motor when it becomes 0 To release the latch.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 8 relate to an embodiment of the present invention, FIG. 1 is a flowchart showing a switching determination routine between a series traveling mode and a parallel traveling mode, FIG. 2 is a flowchart showing a control routine in a series traveling mode, and FIG. FIG. 4 is a flowchart showing a control routine for shifting from the series traveling mode to the parallel traveling mode.
Is a flowchart showing a control routine in the parallel traveling mode, FIG. 5 is a flowchart showing a control routine for shifting from the parallel traveling mode to the series traveling mode, FIG. 6 is an explanatory diagram of a driver request torque map, and FIG. FIG. 8 is an explanatory diagram showing a relationship between a vehicle speed and a driver required torque, and FIG. 8 is an explanatory diagram showing a configuration of a drive control system.

As shown in FIG. 8, the hybrid vehicle according to the present invention includes an engine 1, a motor A (first motor) for starting the engine 1, generating power and assisting power, and a motor attached to an output shaft 1 a of the engine 1. A planetary gear unit 3 connected via A, a motor B (second motor) which controls the function of the planetary gear unit 3 and serves as a driving force source for starting and reversing and recovering deceleration energy; And a power conversion mechanism 4 that performs a torque conversion and performs a power conversion function during traveling.

Specifically, the planetary gear unit 3
A single pinion type planetary gear having a sun gear 3a, a carrier 3b rotatably supporting a pinion meshing with the sun gear 3a, and a ring gear 3c meshing with the pinion. The sun gear 3a is fastened to the carrier 3b.
A lock-up clutch 2 for disengaging is provided.

As the power conversion mechanism 4, a transmission combining a gear train, a transmission using a fluid torque converter, or the like can be used, but a primary pulley 4b supported by an input shaft 4a and a transmission It is desirable to employ a belt-type continuously variable transmission (CVT) in which a drive belt 4e is wound around a secondary pulley 4d supported by the output shaft 4c. In the present embodiment, a power conversion mechanism will be described below. 4 will be described as CVT4.

That is, in the drive system of the hybrid vehicle of the present embodiment, the planetary gear unit 3 having the lock-up clutch 2 interposed between the sun gear 3a and the carrier 3b includes the output shaft 1a of the engine 1 and the input shaft 4a of the CVT 4.
The sun gear 3a of the planetary gear unit 3 is coupled to the output shaft 1a of the engine 1 via one motor A, and the carrier 3b is coupled to the input shaft 4a of the CVT 4 as a power output stage. The other motor B is connected to the ring gear 3c. And
A differential mechanism 6 is connected to an output shaft 4 c of the CVT 4 via a reduction gear train 5, and a drive wheel 8 of a front wheel or a rear wheel is connected to the differential mechanism 6 via a drive shaft 7.

In this case, as described above, the engine 1 and the motor A are connected to the sun gear 3a of the planetary gear unit 3, and the motor B is connected to the ring gear 3c to obtain an output from the carrier 3b. Since the output is shifted and torque amplified by the CVT 4 and transmitted to the driving wheels 8, the two motors A and B can be used for both power generation and driving force supply, and a relatively small output motor Can be used.

The sun gear 3a of the planetary gear unit 3 is operated by the lock-up clutch 2 in accordance with running conditions.
And the carrier 3b, it is possible to form a drive shaft directly connected to the engine from the engine 1 to the CVT 4 in which the two motors A and B are disposed between the two motors A and B.
The driving force can be transmitted to the VT 4 or the braking force from the driving wheel 8 can be used.

The torque transmission of the engine 1 and the motors A and B via the planetary gear unit 3 when the lock-up clutch 2 is engaged and disengaged and the flow of electricity due to power generation are described in Japanese Patent Application No. Flat 10-4080
Issue.

The above drive system is controlled by a control system (hybrid control system) for controlling the running of a hybrid vehicle in which seven electronic control units (ECUs) are connected by a multiplex communication system. Is composed of a microcomputer and a functional circuit controlled by the microcomputer.

More specifically, a hybrid ECU (HEV_ECU) 20 for controlling the whole system is mainly used, and a motor A controller 21 for controlling the driving of the motor A, a motor B controller 22 for controlling the driving of the motor B, and the engine 1 are controlled. Engine ECU (E / G_ECU) 2
3, a transmission ECU (T / M_ECU) 24 for controlling the lock-up clutch 2 and the CVT 4, and a battery management unit (BAT_MU) 25 for managing the power of the battery 10 include a first multiplex communication line 3.
A brake ECU (BRK_ECU) 26 that is connected to the HEV_ECU 20 at 0 and performs brake control is connected to the HEV_ECU 20 via a second multiplex communication line 31.

The HEV_ECU 20 controls the entire hybrid control system, and includes sensors and switches for detecting a driving operation state of the driver, for example, an accelerator pedal sensor (APS) 11 for detecting a depression amount of an accelerator pedal (not shown). A brake switch 12 which is turned on by depressing a brake pedal (not shown);
A shift range switch 14 for detecting the operation range position of the select mechanism unit 13 of the transmission is connected.

The HEV_ECU 20 calculates a required vehicle drive torque based on signals from the respective sensors and switches and data transmitted from the respective ECUs to determine a torque distribution of the drive system. To send a control command.

The HEV_ECU 20 has various indicators for displaying the operating state of the vehicle, such as the vehicle speed, the engine speed, the state of charge of the battery, etc., and a display 27 comprising a warning lamp for warning the driver when an abnormality occurs. Is connected. The indicator 27 is also connected to the T / M_ECU 24, and when an abnormality occurs in the HEV_ECU 20, the T / M_ECU 2 replaces the HEV_ECU 20.
4 performs an abnormal-time control, and displays an abnormality on the display 27.

On the other hand, the motor A controller 21 has an inverter for driving the motor A,
Basically, the constant rotation speed control of the motor A is performed by a servo ON / OFF command and a rotation speed command transmitted from the HEV_ECU 20 by multiplex communication. Further, the motor A controller 21 feeds back the torque, rotation speed, current value, and the like of the motor A to the HEV_ECU 20, and transmits data such as a torque limit request and a voltage value.

The motor B controller 22 includes an inverter for driving the motor B, and basically includes a servo ON / OFF (including forward rotation and reverse rotation) command and torque transmitted from the HEV_ECU 20 by multiplex communication. The constant torque control of the motor B is performed by a command (powering, regeneration). Also, HE from the motor B controller 22
The torque, the number of revolutions, the current value, and the like of the motor B are fed back and transmitted to the V_ECU 20, and data such as the voltage value is transmitted.

The E / G_ECU 23 basically controls the torque of the engine 1, and the HEV_ECU 20
And positive / negative torque command, fuel cut command, control command such as air conditioner ON / OFF permission command, etc., and actual torque feedback data, vehicle speed, shift range position by shift range switch 14, APS
Accelerator full open data and accelerator full close data by the signal of signal No. 11, ON / OFF state of brake switch 12,
Based on the brake operation state including S, a fuel injection amount from an injector (not shown), a throttle opening degree by an ETC (electric throttle valve), power correction learning of auxiliary equipment such as an A / C (air conditioner), fuel cut, etc. Control.

In the E / G_ECU 23, HEV_
The ECU 20 issues a control torque value of the engine 1, a fuel cut, a full-open increase correction to the fuel injection amount,
The HEV_ECU sends the ON / OFF state of the air conditioner, data on the throttle valve fully closed by an idle switch (not shown), and the like.
20 and send it back to the engine 1
Is transmitted.

T / M_ECU 24 is provided by HEV_ECU 2
From 0, the target primary pulley rotation speed of the CVT 4 transmitted by multiplex communication, a control command such as a CVT input torque instruction, a lock-up request, and the like, an E / G rotation speed, an accelerator opening, a shift range position by the shift range switch 14, The engagement and release of the lock-up clutch 2 is controlled based on information such as the ON / OFF state of the brake switch 12, the air conditioner switching permission, the brake operation state including the ABS, the data on the throttle valve fully closed of the engine 1 by the idle switch, and the like. The gear ratio of the CVT 4 is controlled.

From the T / M_ECU 24, the HEV
_ECU 20 for vehicle speed, input limiting torque, CVT4
E / G for increasing the oil amount of the CVT 4 while feeding back and transmitting data such as the primary pulley rotational speed and the secondary pulley rotational speed, lock-up completion, the shift state corresponding to the shift range switch 14, and the like.
A request for increasing the number of revolutions, a low-temperature start request, and the like are transmitted.

The BAT_MU 25 is a so-called power management unit, and performs various controls for managing the battery 10, that is, charge / discharge control of the battery 10, fan control, external charging control, and the like.
Data such as voltage and current limit values and data indicating that external charging is being performed are transmitted to the HEV_ECU 20 by multiplex communication. When performing external charging, the contactor 9 is switched to disconnect the battery 10 from the motor A controller 21 and the motor B controller 22.

The BRK_ECU 26 is provided by the HEV_ECU 2
A necessary braking force is calculated based on information such as a regenerable amount and regenerative torque feedback transmitted by multiplex communication from 0, and a hydraulic pressure of a brake system is controlled.
A regenerative amount command (torque command), a vehicle speed, a hydraulic pressure, a brake operation state including ABS and the like are fed back and transmitted to the HEV_ECU 20.

When viewed from the transmission input shaft (4a), the driving modes of the hybrid vehicle controlled by the above-described hybrid control system can be broadly classified into the following three basic modes, depending on the driving conditions. The state transition of each traveling mode is repeated.

(1) Series (series & parallel) traveling mode When the required driving force or vehicle speed is low, the lock-up clutch 2 is released, the motor 1 is driven by the engine 1 as a generator, and the vehicle mainly travels with the motor B. At this time,
Part of the driving force of the engine 1 is a planetary gear unit 3
Of the sun gear 3a of the ring gear 3c
And is output from the carrier 3b.

(2) Parallel running mode When the required driving force or the vehicle speed is high, the lock-up clutch 2 is engaged and the sun gear 3 of the planetary gear unit 3 is engaged.
a and the carrier 3b, the driving force of the engine 1 is added to the driving force of the motor B from the ring gear 3c and output from the carrier 3b, and the torque of the engine 1 alone or both the engine 1 and the motor B is used. To run.

(3) Regenerative braking mode In braking, the motor B regenerates the braking force in coordination with the brake control. That is, the regenerative braking is performed by cooperatively sharing the braking torque corresponding to the depression amount of the brake pedal with the regenerative torque by the motor B and the braking torque by the brake mechanism.

Hereinafter, the switching determination process of each traveling mode by the HEV_ECU 20 and the transition control between each traveling will be described with reference to the flowcharts of FIGS.

FIG. 1 shows a routine for determining whether to switch between the series traveling mode and the parallel traveling mode. First, in step S51, the current vehicle speed V, the primary pulley rotation speed Np of the CVT 4, the engagement / disengagement of the lock-up clutch 2 are performed. When the state is input from the T / M_ECU 24 by multiplex communication, the accelerator opening Acc is calculated based on the signal from the APS 11 and the shift range position is calculated based on the signal from the shift range switch 14 in step S52.

In the following step S53, the accelerator opening A
Based on cc and the primary pulley rotation speed Np, depending on whether the shift range position belongs to a traveling (forward traveling) range, a neutral or parking range, or a reverse range, the CVT is set for each range as shown below.
The driver request torque Tdrv, which is the input torque of No. 4, is calculated. The driver required torque Tdrv is an output torque of the power stage calculated in consideration of the power distribution by the planetary gear 3, the remaining battery capacity, and the like.
It is possible to represent the required driving torque of the vehicle by a simple process without performing a complicated calculation in consideration of the influence of the torque conversion loss and the like.

(A) Traveling (Forward Traveling) Range The driver required torque Tdrv is determined by the accelerator opening Acc reflecting the driver's operation amount and the carrier 3b of the planetary gear 3 reflecting the output state of the engine 1 and the motors A and B. A function fa (Acc, N) having the rotation speed, that is, the primary pulley rotation speed Np of the CVT 4 as a parameter.
p). Specifically, a value obtained by a simulation or an experiment in advance using the accelerator opening Acc and the primary pulley rotation speed Np as parameters is stored in a map, and the map is referred to. The driver request torque Tdrv is calculated.

(B) Neutral or parking range In the neutral or parking range, it is assumed that there is no need for a positive drive torque, and the driver required torque is set to Tdrv = 0.

(C) Reverse range In the reverse range, basically, the driver required torque Td
rv is the same as that in the traveling (forward traveling) range, but since the traveling direction is reversed, the driver request torque Tdrv is given a minus sign and −fa (Acc,
Np).

FIG. 6 shows a map fa of the driver request torque Tdrv using the accelerator opening Acc and the primary pulley rotation speed Np as parameters, and shows the accelerator opening Ac.
As the value of c increases, the value of the driver required torque Tdrv increases. At the same accelerator opening, the driver required torque Tdrv decreases as the primary pulley rotation speed Np decreases.
Also increases.

From the above, the driver required torque Tdrv
After calculating the vehicle speed V1, a clutch release determination vehicle speed V1of for determining release of the lock-up clutch 2 is calculated by comparing the clutch release determination vehicle speed V1of with the current vehicle speed V. Considering the influence of the gear ratio, when shifting from the parallel running mode to the series running mode, the area where the fuel efficiency of the engine 1 and the efficiency of the motors A and B are optimized corresponding to the driver required torque Tdrv is determined. And a function f having the driver request torque Tdrv as a parameter.
It is obtained as a vehicle speed for determination based on 1 of (Tdrv).
Specifically, values obtained by simulation or experiments are stored in a table in advance, and the values are calculated with reference to this table.

Next, in step S55, a clutch engagement determination vehicle speed V1on for determining engagement of the lock-up clutch 2 is calculated by comparison with the current vehicle speed V. Similarly, the vehicle speed V1on for determining the clutch engagement is determined by the CVT
In consideration of the influence of the gear ratio 4 and its gear ratio, when shifting from the series traveling mode to the parallel traveling mode, the region where the fuel efficiency of the engine 1 and the efficiency of the motors A and B are optimal in accordance with the driver required torque Tdrv is determined. This is determined as the vehicle speed for determination by the function f1on (Tdrv) using the driver request torque Tdrv as a parameter. Specifically, values obtained by simulation or experiments are stored in a table in advance, and the values are calculated with reference to this table.

As shown in FIG. 7, the vehicle speed V1of for determining the clutch release and the vehicle speed V1on for determining the engagement of the clutch increase as the driver request torque Tdrv increases.
The vehicle speed for determination is set to be low, and during traveling in the series traveling mode, it is possible to shift to the parallel traveling mode at a vehicle speed at which the fuel efficiency of the vehicle is optimal while reflecting the driver's intention to accelerate, During traveling in the parallel traveling mode, it is possible to shift to the series traveling mode at a vehicle speed at which the fuel efficiency of the vehicle is optimal while reflecting the driver's intention to decelerate. At the same driver request torque Tdrv, V1of <V1on
To prevent hunting when releasing and engaging the clutch.

Then, the process proceeds to a step S56, wherein the current vehicle speed V is compared with the clutch engagement determination vehicle speed V1on.
In the case of V1on, the process proceeds to step S57, and the parallel running condition establishment flag FL is set to indicate that the condition for switching from the series running mode to the parallel running mode has been satisfied.
AG1 is set (FLAG1 ← 1), and the parallel → series transition control completion flag FLAG3 is cleared (FLAG3 ← 1) to indicate that the transition control from the parallel traveling mode to the series traveling mode has not been performed.
0), and proceed to step S60.

If V <V1on in step S56, the flow branches to step S58 to compare the current vehicle speed V with the clutch release determination vehicle speed V1of. And V>
If V1of, that is, the current vehicle speed V is between the vehicle speed V1on for clutch engagement determination and the vehicle speed V1of for clutch release determination (V1on>V> V1of), the process jumps to step S60 to maintain the current traveling mode, V
If ≦ V1of, the parallel running condition establishment flag FLAG1 is set in step S59 to indicate that the condition for switching from the parallel running mode to the series running mode has been satisfied.
(FLAG1 ← 0) and the series → parallel transition control completion flag FLAG2 is cleared (FLAG2 ← 0) to indicate that the transition control from the series traveling mode to the parallel traveling mode has not been performed.
Proceed to step S60.

Next, in step S60, the value of the parallel running condition satisfaction flag FLAG1 is referred to
If the condition for switching from the series traveling mode to the parallel traveling mode is satisfied in step 1, the program proceeds to step S
At 61, the series-to-parallel transition control completion flag FLA
With reference to the value of G2, it is checked whether or not the transition control from the series traveling mode to the parallel traveling mode has been completed.

As a result, in step S61, FL
If AG2 = 0 and the transition control from the series traveling mode to the parallel traveling mode is not completed, in step S62, the transition control from the series traveling mode to the parallel traveling mode by the transition control routine of FIG.
When the control for shifting from the series traveling mode to the parallel traveling mode has already been completed at = 1, the parallel traveling control is performed in step S63 by the control routine of FIG.

On the other hand, the result of referring to the parallel running condition satisfaction flag FLAG1 in step S60, FLAG1 =
0, and if the switching condition from the parallel traveling mode to the series traveling mode is satisfied, the process proceeds to step S
From 60, the process proceeds to step S64 to refer to the value of the parallel → series transition control completion flag FLAG3.

If FLAG3 = 0 and the transition control from the parallel traveling mode to the series traveling mode is not completed, the transition control from the parallel traveling mode to the series traveling mode by the transition control routine of FIG. 5 is performed in step S65. If FLAG3 = 1 and the transition control from the parallel traveling mode to the series traveling mode has already been completed, the series traveling control according to the control routine of FIG. 2 is performed in step S66.

Next, regarding the control of each driving mode and the transition control between the driving modes determined by the above-mentioned driving mode switching determination, a series driving mode, a transition control from a series driving to a parallel driving mode, a parallel driving control, A description will be given in the order of the control for shifting from parallel traveling to series traveling.

In the series running mode, in the control routine shown in FIG. 2, first, in step S101, when a rotational speed command for causing the motor A controller 21 to operate the motor A at a constant speed at a predetermined rotational speed is given to the motor A controller 21 by multiplex communication, In S102, the driver request torque Tdrv is calculated based on the accelerator opening Acc and the primary pulley rotation speed Np of the CVT4.

Next, the routine proceeds to step S103, where the driver's required torque Tdrv is
Is divided into the ring gear side torque Tr and the sun gear side torque Ts calculated by the following equations (1) and (2) using the planetary gear ratio (planetary ratio: constant K). Tr = Tdrv × (1-K) / K (1) Ts = Tdrv × K (2)

In the following step S104, the ring gear 3
The required power Wb of the motor B connected to the motor c is calculated from the rotation speed of the motor B and the torque Tr on the ring gear side, and a predetermined charging power Wa is calculated from the remaining capacity of the battery 10 in step S105. Then, in step S106, a torque Tbat for power generation is calculated from the required power Wb of the motor B, the charged power Wa of the battery 10, and the number of revolutions of the motor A. In step S107, as shown in the following equation (3): Then, the driving torque Teg of the engine 1 is calculated by adding the torque Ts on the sun gear side and the generated torque Tbat. Teg = Ts + Tbat (3)

Thereafter, the process proceeds to step S108, where the drive torque Teg calculated in step S107 is calculated based on the power generated by the motor A and the output characteristics of the engine 1.
It is checked whether the output is possible from the motor A. If it is difficult to output the driving torque Teg, the rotation speed of the motor A is changed to give a new rotation speed command to the motor A controller 21, and the motor B
, The generated torque Tbat is calculated from the required power Wb, the charged power Wa of the battery 10, and the rotation speed of the motor A, and the generated torque Tbat and the torque Ts on the sun gear side are added to calculate the driving torque Teg of the engine 1. .

In step S109, a torque command is given to the motor B controller 22 by multiplex communication using the torque Tr on the ring gear side as the torque of the motor B, and in step S110, a torque command of the driving torque Teg is given to the E / G_ECU 23 by multiplex communication. To step S111.

In step S111, the motor A controller 21, the motor B controller 22, the E / G_ECU
With the feedback value of the vehicle drive torque calculated based on each feedback value from 23, the driving by the motor B is controlled and the routine is exited.

That is, in the HEV_ECU 20, the power feedback torque Ta ′ for the motor A received from the motor A controller 21 and the torque feedback value T for the motor B received from the motor B controller 22
b ′, the reaction force of the torque of the motor B (Tb ′ × K (1
-K)) and feeds back to the E / G_ECU 23, where the HEV_ECU 20
Command value Teg and feedback value (Ta '
+ Tb ′ × K / (1−K)) and controls the engine 1 by learning the difference.

Then, the torque feedback value Te of the engine 1 is added to the torque feedback value Tb ′ of the motor B.
g ′ and the torque feedback value Ta ′ of the motor A are added to obtain a feedback value of the driver required torque, and the feedback value (T
b ′ + Teg′−Ta ′), and the traveling control by the motor B is performed.

Thus, in the low load series running mode in which the required driving force is small, the power consumption of the battery 10 due to the driving of the motor B can be supplemented while the reaction force of the motor B is supported by the engine 1 and the motor A. , Stable constant torque running can be ensured.

Next, transition control when switching from the series traveling mode to the parallel traveling mode will be described.

The transition from the series traveling mode to the parallel traveling mode is performed by the transition control routine shown in FIG. 2. Before the lock-up clutch 2 is engaged, the engine torque is gradually increased in advance to approach the driver required torque. Thereafter, the rotation speed of the motor A is made to match the rotation speed of the primary pulley, which is the input shaft rotation speed of the CVT 4, and the lock-up clutch 2 is engaged.

Specifically, first, at step S201, T
In order to match the rotation speed Na of the motor A with the rotation speed Na of the primary pulley, which is fed back from the / M_ECU 24, a rotation speed command is given to the motor A controller 21 by multiplex communication. The actual rotation speed Nar of the motor A is detected based on the rotation speed data.

Next, the process proceeds to step S203, in which the driving torque Teg of the engine 1 is changed from the state of the generated torque or the torque 0 to the driver required torque Tdrv during the parallel running.
, The current drive torque Teg is increased by a predetermined value Tk.
Is added to calculate a new driving torque Teg (Teg ←
Teg + Tk), and in step S204, E
/ G_ECU 23 is given a torque command value of drive torque Teg.

Thereafter, in step S205, it is checked whether or not the absolute value | Tdrv-Teg | of the difference between the driver request torque Tdrv and the engine driving torque Teg has become equal to or smaller than the set value Kt. As a result, | Tdrv-Teg | > K
At time t, the process exits the routine and continues the process of increasing the engine command torque by the predetermined value Tk, and | Tdrv-T
When eg││Kt, the routine proceeds to step S206, where the primary pulley rotation speed Np and the actual rotation speed Na of the motor A are set.
It is checked whether or not the absolute value | Np-Nar | of the difference from r has become equal to or smaller than the set value Kn.

The set value Kn depends on the rotation speed of the motor A and the CVT.
4 determines the allowable range in which the primary pulley rotational speeds can be considered to be substantially the same. If | Np-Nar |> Kn in step S206, the routine exits and the rotational speed command (Na = N
The processing for matching the rotation of the motor A with the rotation of the primary pulley according to p) is continued. At this time, the output torque of the motor A becomes negative by the control to increase the driving torque of the engine 1 and the rotation speed control to the primary pulley rotation speed Np of the motor A.

Then, in step S206, | Np
−Nar ≦ Kn, and when the actual rotation speed Nar of the motor A substantially matches the primary pulley rotation speed Np,
Proceed to step S207 to execute T / M_EC by multiplex communication.
A command to engage the lock-up clutch 2 is given to U24, and the series-to-parallel transition control completion flag FLAG2 is set in step S209, and the routine exits.

As described above, when shifting from the series traveling mode to the parallel traveling mode, the engine 1
After the drive torque of the motor A is gradually increased so as to become the driver required torque in the parallel traveling mode, the rotation speed of the motor A is substantially changed with respect to the rotation speed of the primary pulley of the CVT 4 directly connected by the engagement of the lock-up clutch 2. , The controllability of the rotation speed control for the motor A is improved, and not only the rotation fluctuation and torque fluctuation can be minimized, but also the clutch can be smoothly engaged. It is not necessary to switch the torque from the state of power generation torque or torque 0 in series running to the driver's required torque in a short time immediately after the clutch is engaged, so transient torque due to a large response delay of the engine torque relative to the motor torque. Shock due to shortage or excessive torque can be avoided.

When the driving torque of the engine 1 is switched to the driver required torque immediately after the clutch is engaged,
First, immediately before the clutch is engaged, the output torque of the engine 1 is temporarily set to 0. Immediately after the clutch is engaged, the output torque of the engine 1 is switched from 0 to the driver required torque.
Since the output torque of the motor B must be switched from the driver required torque to zero, the two have different torque responsiveness, and the controllability is not necessarily good.

On the other hand, according to the present invention, when shifting from the series running mode to the parallel running mode, the engine 1
After the drive torque of the motor A is gradually increased so as to be the driver required torque in the parallel traveling mode, the rotational speed of the motor A is substantially matched with the primary pulley rotational speed, and then the clutch is engaged. The torque can be exchanged between the motors immediately after the fastening of No. 2 and the controllability can be improved.

That is, in the parallel running control routine of FIG. 4, when the lock-up clutch 2 is engaged and the mode is shifted from the series running mode, first, in step S301.
To give a motor 0 controller 21 a torque 0 command to make the motor A torque 0 by multiplex communication. In this case, immediately after the transition from the series traveling mode to the parallel traveling mode, that is, immediately after the lock-up clutch 2 is engaged, the torque of the motor B is simultaneously transmitted to the motor B controller 22 by the driving torque during the series traveling (driver required torque). ), A torque command for temporarily setting the torque to 0 is given.

As described above, in the transition control from the series traveling mode to the parallel traveling mode, the driving torque of the engine 1 is gradually increased to the driver required torque, and the rotation speed of the motor A is substantially reduced to the primary rotation speed. Since the rotation speed control is performed so as to make them coincide with each other, the motor A and the motor B are controlled with the torque 0 immediately after the shift to the parallel running, that is, immediately after the lock-up clutch 2 is engaged, so that the negative output torque of the motor A is reduced. Can be absorbed via the planetary gears by controlling the torque of the motor B to be zero, and the motors having the same torque response can exchange torque. As a result, it is possible to reduce the shock at the time of clutch engagement, improve the durability of the clutch, and reduce the size of the clutch.

In the parallel running mode, the lock-up clutch 2 is engaged to connect the sun gear 3a of the planetary gear unit 3 and the carrier 3b, and the sun gear 3a
Since the driving force of the motor B from the ring gear 3c is added to the driving force of the engine 1 and output from the carrier 3b, the output torque of the engine 1 and the motor B can be directly transmitted to the driving wheel side by the motor A The number of rotations must be adjusted to a certain degree, and control is difficult. in this case,
If the rotation speed control of the motor A is maintained in the series running mode, the driving torque is absorbed by the motor A. On the other hand, if the rotation speed control of the motor A is stopped, the output torque of the engine 1 and the motor B due to iron loss. Is reduced.

In any case, it is difficult to control the vehicle drive torque in the parallel traveling mode if the motor A is kept under the rotational speed control in the series traveling mode. Therefore, the rotation speed of the motor A is controlled in the parallel traveling mode. By giving a torque 0 command to the motor A controller 21, the motor A is set to a torque 0 by weakening field or the like, and the engine 1
Output torque and motor B output torque without loss
Input to T4.

Then, after the motor A is operated at the torque of 0, the process proceeds to step S302 to calculate the driver required torque Tdrv based on the accelerator opening Acc and the primary pulley rotation speed Np, and the remaining capacity of the battery 10 is determined in step S303. Is checked to see if it is greater than or equal to a predetermined value. As a result, when the state of charge of the battery 10 is smaller than the predetermined value, E / G_E is performed by multiplex communication in step S304 to run only the engine 1 according to the throttle opening.
A predetermined torque command is given to the CU 23, and step S310
Proceed to.

On the other hand, if the remaining capacity of the battery 10 is equal to or larger than the predetermined value in step S303, the process proceeds to step S3.
From step 03, the process proceeds to step S305 to calculate the engine maximum output torque Tegmax from the throttle opening of the engine 1 and the primary pulley rotation speed Np of the CVT 4. Then, in step S306, the driver request torque Tdr
difference ΔT between v and the engine maximum output torque Tegmax
(ΔT = Tdrv−Tegmax), and the difference ΔT is set as the drive torque Tb of the motor B (Tb = ΔT) in step S307.

That is, in the parallel traveling mode, when the driver request torque Tdrv is larger than the maximum output torque Tegmax determined from the equal throttle opening curve of the engine 1, the motor B assists the corresponding torque. (Tdrv−Tegmax) is set as the driving torque of the motor B.

Then, in step S308, the maximum engine output torque Teg is transmitted to the E / G_ECU 23 by multiplex communication.
In step S309, a torque command of max is given.
To give a torque command of the driving torque Tb to the motor B controller 22 by multiplex communication, and the torque feedback value Tb 'of the motor B received from the motor B controller 22 and the torque feedback value Teg of the engine 1 received from the E / G_ECU 23 in step S310. The running control is performed using the value (Tb ′ + Teg ′) obtained by adding “'” as the feedback value of the vehicle driving torque, and the routine exits.

In the parallel running mode, the engine 1
And the torque distribution between the motor B and the motor B is determined, and the traveling by the engine 1 alone or the assist traveling by assisting the engine 1 with the motor B is performed. However, the motor A is not switched from the rotation speed control to the torque control in earnest. With simple commands and limited constant torque control, the output torque of the engine 1 and the motor B can be transmitted to the drive wheels without loss, and the drive torque can be easily controlled.

Next, the transition from the parallel traveling mode to the series traveling mode is performed by the transition control routine of FIG. In this routine, the torque of the engine 1 is gradually reduced, and the corresponding torque is output from the motor B. When the torque of the engine 1 becomes 0, the torque 0 command of the motor A is released and the motor B is released. The rotation speed of A is adjusted to the rotation speed of motor B, and lock-up clutch 2 is released.

That is, first, in step S401, a torque command of a torque value Teg (Teg = Teg−Teg / n) obtained by reducing the engine driving torque Teg by a predetermined ratio n is given to the E / G_ECU 23 by multiplex communication.
Next, in step S402, the decrease Teg / n of the engine driving torque is added to the current driving torque Tb of the motor B to obtain a new driving torque Tb of the motor B (Tb + Tb).
/ N) to the motor B controller 22 by multiplex communication with the torque command of the new drive torque Tb.

Then, in step S403, it is determined whether or not the engine drive torque Teg has become zero.
If eg ≠ 0, the routine exits from the step S403 and the torque of the engine 1 is reduced by a predetermined amount.
The process of increasing the torque by a predetermined amount is repeated.

Thereafter, when the engine drive torque Teg becomes 0 in step S403, the process proceeds to step S404, where the rotation speed Nb of the motor B is detected, and in step S405, the torque of the motor A controller 21 for the motor A becomes 0.
In order to cancel the command and make the rotation speed Na of the motor A the same as the rotation speed Nb of the motor B, the motor A controller 2
1 is given a rotational speed command. Then, in step S406, a command to release the lock-up clutch 2 is given to the T / M_ECU 24 by multiplex communication. In step S407, the parallel-to-series shift control completion flag FLAG3 is set, and the routine exits.

That is, in the transition from the parallel traveling mode to the series traveling mode, the torque of the engine 1 is gradually reduced to zero before the lock-up clutch 2 is released by adjusting the rotation speed of the motor A and the rotation speed of the motor B. , And the corresponding torque is output from the motor B, so that it is possible to shift from the parallel traveling mode to the series traveling mode without causing rotation fluctuations and torque fluctuations, thereby preventing deterioration in driving feeling. be able to.

[0087]

As described above, according to the first aspect of the present invention, when shifting from the series running mode in which the lock-up clutch is released and running to the parallel running mode in which the lock-up clutch is engaged and running. The drive torque of the engine is gradually increased to shift to the drive torque in the parallel traveling mode, and then the rotation speed of the first motor is made substantially equal to the rotation speed of the input shaft of the power conversion mechanism. In addition to minimizing rotation and torque fluctuations associated with the engagement and disengagement of the lock-up clutch, the clutch can be smoothly engaged, and the engine torque can be reduced to the parallel drive mode torque immediately after the clutch engagement. The response delay of the engine torque to the motor torque is large Shock can be avoided in advance by the transient torque shortage and torque excessive by the.

According to the second aspect of the present invention, the shift from the series traveling mode to the parallel traveling mode is performed.
Performing in the same manner as the described invention, when shifting from the parallel traveling mode to the series traveling mode, the driving torque of the engine is gradually reduced and the driving torque of the second motor is gradually reduced by the reduced amount of the driving torque of the engine. In order to release the lock-up clutch by substantially matching the rotation speed of the first motor with the rotation speed of the second motor when the driving torque of the engine becomes substantially zero. In both cases of engagement and disengagement of the up-clutch, a shock can be prevented to further improve the driving feeling, and smooth running can be realized.

[Brief description of the drawings]

FIG. 1 is a flowchart showing a switching determination routine between a series traveling mode and a parallel traveling mode.

FIG. 2 is a flowchart showing a control routine in a series traveling mode.

FIG. 3 is a flowchart showing a control routine for shifting from a series traveling mode to a parallel traveling mode.

FIG. 4 is a flowchart showing a control routine in a parallel traveling mode.

FIG. 5 is a flowchart showing a control routine for shifting from a parallel traveling mode to a series traveling mode.

FIG. 6 is an explanatory diagram of a driver request torque map.

FIG. 7 is an explanatory diagram showing a relationship between a vehicle speed for clutch engagement / disengagement determination and a driver required torque.

FIG. 8 is an explanatory diagram showing a configuration of a drive control system.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Engine 2 ... Lock-up clutch 3 ... Planetary gear unit (single pinion type planetary gear) 3a ... Sun gear 3b ... Carrier 3c ... Ring gear 4 ... Belt type continuously variable transmission (power conversion mechanism) A ... 1st motor B ... 2nd Motor 20 ... HEV_ECU

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (reference) F02B 61/00 F02D 29/06 D F02D 29/02 B60K 9/00 Z 29/06 F term (reference) 3D039 AA01 AA02 AA03 AA04 AA07 AB27 AC21 AC34 AD06 AD11 3D041 AA04 AA11 AA31 AA66 AA80 AB01 AC20 AD00 AD01 AD02 AD04 AD10 AD31 AD32 AD33 AD41 AD42 AD52 AE02 AE07 AE08 AE36 AE37 AF01 AF07 BA04 A07 A07 A07 BA06 DB12 DB15 DB25 EA05 EB03 EB08 EC01 FA07 FA09 FA10 FB01 FB02 FB03 5H115 PA00 PA01 PA12 PC06 PG04 PI16 PI29 PI30 PO02 PO17 PU08 PU22 PU24 PU27 PV09 QA01 QE01 QE09 QE10 QE13 QH08 QI04 QI07 QN03 SEN RE09 QN09 TI02 TI05 TI06 TO12 TO13 TO21 TO23 TO26 TO30 TZ07 UB05 UI13 UI23

Claims (2)

[Claims] A first motor connected between an output shaft of an engine and a sun gear of a single pinion type planetary gear, a second motor connected to a ring gear of the planetary gear, a sun gear of the planetary gear and a carrier are fastened. A lock-up clutch to be disengaged, and a power conversion mechanism that is connected to the carrier of the planetary gears and that performs speed change and torque amplification between the planetary gears and the drive wheels according to a speed ratio that can be switched in a plurality of steps or steplessly. A hybrid vehicle control device for switching a traveling mode of a hybrid vehicle provided between a series traveling mode in which the lock-up clutch is released and traveling and a parallel traveling mode in which the lock-up clutch is engaged and traveling, From the series running mode to the above parallel running mode At the time of the shift, the drive torque of the engine is gradually increased to shift to the drive torque in the parallel traveling mode, and then the rotation speed of the first motor is substantially set to the input shaft rotation speed of the power conversion mechanism. And a means for engaging the lock-up clutch. 2. When shifting from the parallel running mode to the series running mode, the drive torque of the engine is gradually reduced, and the drive torque of the second motor is gradually reduced by the reduced drive torque of the engine. The lockup clutch is disengaged by substantially increasing the rotation speed of the first motor to the rotation speed of the second motor when the driving torque of the engine becomes substantially zero. 2. The apparatus according to claim 1, further comprising:
A control device for a hybrid vehicle as described in the above.