JP4110277B2 - Control device for hybrid vehicle - Google Patents

Description

  The present invention relates to a hybrid vehicle in which an engine, a first motor, a second motor, and an output shaft are connected to each other by a differential gear mechanism having four rotating elements, and the hybrid vehicle can stop and control the engine during traveling. More specifically, the present invention relates to a hybrid vehicle control device in which an engine is started by a first motor and a second motor.

  In recent years, various types of hybrid vehicles have been proposed for improving fuel efficiency and reducing exhaust gas due to environmental problems and the like. In such a hybrid vehicle, for example, a planetary gear unit (a so-called Ravigneaux type or a Simpson type) in which two planetary gears are connected is used, and an engine (input shaft) and a first motor are provided for each of the four rotating elements. A two-motor split hybrid vehicle having a configuration in which a second motor and an output shaft are connected has been proposed (see, for example, Patent Document 1). In this hybrid vehicle, the engine is driven and controlled, and the vehicle is driven while being regenerated and powered by the first and second motors, so-called split running, and the engine is stopped and controlled by the driving force of the first motor and the second motor. So-called EV traveling is possible.

JP 2001-309507 A.

  By the way, when the engine is started from the EV running state of the hybrid vehicle, the engine, the first motor, and the second motor are connected as described above. By controlling the output torque, the engine can be raised to idle rotation and started. That is, for example, the engine can be started without providing a mechanism such as a starter, and the number of parts in the hybrid vehicle can be reduced and the size can be reduced.

  However, in the state where the output of the first motor and the second motor, in particular, the output torque of the second motor that mainly outputs torque to the driving wheel during EV traveling is large, the remaining capacity of the output capacity of the second motor is reduced. It takes a long time to increase the engine speed in order to start the engine (that is, the engine rotational angular acceleration is reduced). As a result, the engine cannot be started quickly (smoothly) and the required torque requested by the driver may not be met, or the time required for the engine resonance speed will increase, causing vibrations throughout the vehicle. Problems occur.

  On the other hand, in order to start the engine quickly, it is conceivable to temporarily reduce the output torque of the second motor. However, the acceleration of the vehicle is temporarily reduced and the torque required by the driver is temporarily met. There is a risk that the driver may feel uncomfortable when starting the engine.

  Therefore, the present invention calculates a motor limit torque that leaves a surplus force for smoothly starting the engine by the first motor and the second motor, and during the engine stop control, the first motor and the motor within the motor limit torque are calculated. An object of the present invention is to provide a hybrid vehicle control device that solves the above-mentioned problems by controlling the driving of the second motor.

The present invention according to claim 1 provides an output connected to an input shaft (5) connected to the engine (2), a first motor (3), a second motor (4), and a drive wheel (12). The shaft (6), the input shaft (5), the first motor (3), the second motor (4), and the four rotation elements (S1 and S2, respectively) connected to the output shaft (6). A differential gear mechanism (PU) having CR1 and R2, CR2, R1), and a hybrid vehicle including
Engine control means (20) capable of driving and controlling the engine (2), and motor control means (24) capable of driving and controlling the first motor (3) and the second motor (4), While stopping the engine (2), the first motor (3) and the second motor (4) can be driven and controlled so that the hybrid vehicle can run, and the first motor (3) and the first motor In the hybrid vehicle control device (1) capable of starting the engine (2) by driving and controlling the two motors (4),
The motor control means (24) includes first motor control means (25) capable of controlling the rotational speed (N _MG1 ) of the first motor (3) during stop control of the engine (2) ; Second motor control means (26) capable of torque controlling the output torque (T _MG2 ) of the second motor (4) ,
The motor control means (24) is configured such that the engine (2) is driven by the first motor (3) and the second motor (4) during the stop control of the engine (2) by the engine control means (20). the result drives and controls the second motor (4) within the motor limit torque leaving a margin for smooth start (e.g. T _MG2 _lim),
The motor limit torque (T _MG2 _lim) is the drag torque (−Te) of the engine (2) when the engine (2) is started with the maximum torque (T _MG1 _max) of the first motor (3 ). , Torque (T _MG1 _max) of the first motor (3), and inertia torque (Ie, I _MG1 , I _MG2 ) between the engine (2), the first motor (3), and the second motor (4) ), And is set to a value that can start the engine (2) at an engine rotational angular velocity (dωe) for increasing the engine speed to the idle speed within a predetermined time (t). The
There exists in the control apparatus (1) of the hybrid vehicle characterized by this.

The present invention according to claim 2 includes a limit torque map (31) in which the motor limit torque (for example, T _MG2 _lim) corresponding to the vehicle speed (V) is recorded,
The motor control means (24) drives and controls the second motor (4) within the motor limit torque (eg, T _MG2 _lim) read from the limit torque map (31) based on the vehicle speed (V). Become
It exists in the control apparatus (1) of the hybrid vehicle of Claim 1.

The present invention according to claim 3 includes a limit torque calculating means (27) for calculating the motor limit torque (for example, T _MG2 _lim) at any time,
It said motor control means (24) is formed by driving and controlling said second motor (4) computed the motor limit torque (e.g. _{T MG2} _lim) within the said limit torque calculating means (27),
It exists in the control apparatus (1) of the hybrid vehicle of Claim 1.

According to a fourth aspect of the present invention, there is provided a battery (16) that is freely chargeable / dischargeable with respect to the first motor (3) and the second motor (4),
Battery remaining amount detecting means (29) capable of detecting the remaining charge of the battery (16);
Limit torque correction means (30) for correcting the motor limit torque (for example, T _MG2 _lim) according to the remaining charge amount of the battery (16) detected by the battery remaining amount detection means (29). Become
It exists in the control apparatus (1) of the hybrid vehicle in any one of Claim 1 thru | or 3 .

The present invention according to claim 5 includes driver request torque detection means (28) for detecting driver request torque (T _FTG ) requested by the driver;
Motors that calculate output torques (T _MG1 , T _MG2 ) of the first motor (3) and the second motor (4) in a state where the engine (2) is stopped based on the driver request torque (T _FTG ). Torque calculating means (23);
The motor torque calculating means output torque of the engine which is calculated by (23) (2) before Symbol second motor in a state of stopping (4) _{(T MG2)} is, the motor limit torque (e.g. _{T MG2} _lim) or Engine start determination means (21) for determining start of the engine (2),
The engine control means (20) controls the start of the engine (2) based on the determination result of the engine start determination means (21).
It exists in the control apparatus (1) of the hybrid vehicle in any one of Claims 1 thru | or 4 .

The present invention according to claim 6, wherein the motor torque computing means output torque of the engine which is calculated by (23) (2) the pre-Symbol second motor stopped state (4) (T _MG2) is, the motor An engine stop determining means (22) for determining stop of the engine (2) when the torque is within a limit torque (for example, T _MG2 _lim);
The engine control means (20) is configured to stop the engine (2) based on the determination result of the engine stop determination means (22).
It exists in the control apparatus (1) of the hybrid vehicle of Claim 5 .

  In addition, although the code | symbol in the said parenthesis is for contrast with drawing, this is for convenience for making an understanding of invention easy, and has no influence on the structure of a claim. It is not a thing.

According to the first aspect of the present invention, the motor control means has a motor limit torque that leaves a surplus power for smoothly starting the engine by the first motor and the second motor during the engine stop control by the engine control means. Since the second motor is driven and controlled within the range, when starting the engine, for example, the engine can be started smoothly without reducing the output torque of the first motor and the second motor. It can prevent giving a sense of incongruity. Further, when starting the engine, the motor limit torque is calculated based on the engine rotation angular acceleration for increasing to the idle rotation speed within a predetermined time. Therefore, the engine when starting the engine with the first motor and the second motor is calculated. The rotational angular acceleration can be an engine rotational angular acceleration that can smoothly start the engine, whereby the engine can be started smoothly and the driver can be prevented from feeling uncomfortable.

According to the second aspect of the present invention, the motor control means drives and controls the second motor within the motor limit torque read from the limit torque map based on the vehicle speed, for example, without calculating the motor limit torque as needed. Therefore, when starting the engine, the engine can be started smoothly, thereby preventing the driver from feeling uncomfortable.

According to the third aspect of the present invention, the motor control means can drive and control the second motor within the motor limit torque calculated by the limit torque calculation means. It is possible to start smoothly, thereby preventing the driver from feeling uncomfortable.

According to the fourth aspect of the present invention, the limit torque correction unit corrects the motor limit torque in accordance with the remaining battery charge detected by the remaining battery level detection unit. For example, the remaining battery charge decreases. As a result, even if the voltage supplied to the first motor or the second motor drops and the torque that can be output from the first motor or the second motor becomes low, the engine is smoothly driven from the first motor or the second motor. It is possible to prevent the torque for starting the engine from being output. Thus, when starting the engine, the engine can be started smoothly, thereby preventing the driver from feeling uncomfortable.

According to the fifth aspect of the present invention, the driver request torque detection means detects the driver request torque requested by the driver, and the motor torque calculation means calculates the output torque of the first motor and the second motor based on the driver request torque. The engine start determining means determines that the engine starts when the output torque of the second motor calculated by the motor torque calculating means is equal to or greater than the motor limit torque calculated by the limit torque calculating means, and the engine control means Since the engine is controlled to start based on the determination result of the start determination means, the engine can be started before the second motor exceeds the motor limit torque, whereby the engine can be started smoothly and the driver can It can prevent giving a sense of incongruity.

According to the sixth aspect of the present invention, the engine is stopped when the output torque of the second motor calculated by the motor torque calculating means is within the motor limit torque calculated by the limit torque calculating means. Since the engine control means controls the engine stop based on the determination result of the engine stop determination means, the output torque of the second motor can be made less than the motor limit torque when the engine is stopped, thereby For example, even if the engine is started immediately after that, the engine can be started smoothly and the driver can be prevented from feeling uncomfortable.

  Hereinafter, embodiments according to the present invention will be described with reference to FIGS. 1 to 5. FIG. 1 is a block diagram showing a control device for a hybrid vehicle according to the present invention, FIG. 2 is a skeleton diagram showing the hybrid vehicle according to the present invention, FIG. 3 is a flowchart showing control of the control device for the hybrid vehicle, and FIG. FIG. 5 is an explanatory diagram showing the torque relationship between the engine, the first motor, the second motor, and the output shaft when there is no change, and FIG. 5 shows the relationship between the engine, the first motor, the second motor, and the output shaft when the rotational speed changes. It is explanatory drawing which shows a torque relationship.

  First, a hybrid vehicle to which the present invention can be applied will be described with reference to FIG. As shown in FIG. 2, the hybrid vehicle includes a transmission 10 as an automatic transmission between an engine (E / G) 2 and a drive wheel 12. The transmission 10 includes a first motor (MG1) 3, a second motor (MG2) 4, and a Simpson type planetary gear unit (differential gear mechanism) PU in which two planetary gears are connected. . The planetary gear unit PU includes a sun gear S1 and a sun gear S2, a carrier CR2, a carrier CR1, a ring gear R2, and a ring gear R1 as four rotating elements.

  The crankshaft of the engine 2 is connected to the input shaft 5 of the transmission 10, and the input shaft 5 is connected to the carrier CR2 of the planetary gear unit PU. The carrier CR2 has a pinion P2. The pinion P2 meshes with the sun gear S2 and the ring gear R2. The sun gear S2 is connected to the sun gear S1, and is connected to a rotor (not shown) of the first motor 3 via a connecting shaft 3a. The sun gear S1 meshes with a pinion P1 included in the carrier CR1, and the pinion P1 meshes with the ring gear R1. The ring gear R1 is connected to a rotor (not shown) of the second motor 4 via a connecting shaft 4a. The carrier CR1 is connected to the ring gear R2, the carrier CR1 and the ring gear R2 are connected to the output shaft 6, and the output shaft 6 is connected to the drive wheel 12.

  That is, the four rotational elements of the planetary gear unit PU, the sun gear S1 and the sun gear S2, the carrier CR2, the carrier CR1, the ring gear R2, and the ring gear R1, are meshed with each other and are in a connected relationship. The rotation speed of the engine 2, the rotation speed of the output shaft 6, and the rotation speed of the second motor 4 are connected in a proportional relationship (see, for example, FIG. 9, FIG. 11, FIG. 13, and FIG. 15 in Patent Document 1). .

  Next, a control apparatus 1 for a hybrid vehicle according to the present invention will be described with reference to FIG. In the transmission 10 of the hybrid vehicle, an inverter circuit 15 that controls the supply and regeneration of electric power to the first motor 3 and the second motor 4 is controllable, and electric power supply and charging (regeneration) is performed via the inverter circuit 15. A battery 16 that can be freely operated is provided.

  The control device 1 for the hybrid vehicle includes a control unit (ECU) U. The control unit U detects the vehicle speed by detecting the rotational speed of the drive wheel 12 or the output shaft 6. A sensor 17 is connected to an accelerator frequency sensor 18 that detects an accelerator opening by detecting an angle of an accelerator pedal provided in a driver's seat (not shown).

  Further, the control unit U is provided with engine control means 20 that can freely control the driving of the engine 2 based on, for example, an engine optimum fuel consumption map Emap, and drives the first motor 3 by rotational speed control or torque control. A motor control means 24 having a controllable first motor control means 25 and a second motor control means 26 capable of driving and controlling the second motor 4 by rotation speed control or torque control is provided.

  The first motor control means 25 and the second motor control means 26 command the inverter circuit 15 and drive the first motor 3 and the second motor 4 according to the voltage value / current value controlled by the inverter circuit 15. Although control is performed, in this specification, in order to facilitate understanding of the invention, it is simply referred to as “controlling the first motor 3 and the second motor 4”.

  As will be described in detail later, the control unit U includes an engine start determination unit 21, an engine stop determination unit 22, a motor torque calculation unit 23, a limit torque calculation unit 27, and the like. , A driver request torque detection means 28, a battery remaining amount detection means 29, and a limit torque correction means 30 are provided. The hybrid vehicle control device 1 according to the present invention may include a limit torque map 31 instead of the limit torque calculation means 27 as described in detail later.

Next, control when traveling while the engine 2 is being driven will be described. For example, when the hybrid vehicle is in a traveling state, first, the vehicle speed V is detected by the vehicle speed sensor 17. Then, the rotational speed N _O of the output shaft 6 from the vehicle speed V is calculated.

On the other hand, the driver request torque detection means 28 outputs the entire vehicle requested by the driver from, for example, a map (not shown) based on the vehicle speed V and the accelerator opening Ad detected by the accelerator opening sensor 18. A target drive torque (driver required torque) _TFTG output from the shaft 6 is determined (see, for example, FIG. 5 of Patent Document 1).

Next, based on the vehicle speed V and the target drive torque _TFTG , the engine control means 20 calculates the required engine output E _POW output from the engine 2 by the product of the output shaft speed No based on the vehicle speed V and the target drive torque _TFTG. Calculated from (E _POW = No × T _FTG ). The engine optimum fuel efficiency map and the optimum fuel consumption curve engine 2 becomes the optimum operating condition on the fuel efficiency based on the e-maps, from the above computed engine output E _POW, the target engine speed N _ETG and the target engine torque T _ETG (That is, E _POW = N _ETG × T _ETG ) (see, for example, FIG. 6 of Patent Document 1).

For example, when the remaining amount of charge of the battery 16 is small, the engine output E _POW is calculated by correcting the charge amount α for charging the battery 16 (E _POW = No × T _FTG + α). For example, when the remaining charge of the battery 16 is large, for example, the engine output E _POW is calculated by correcting the discharge amount β corresponding to the amount of power consumed by the battery 16 (E _POW = No × T _FTG − β), a target engine speed _NETG and a target engine torque _TETG are determined based on the corrected engine output E _POW .

Subsequently, the first motor control means 25, based on the engine speed N _O of the output shaft 6 which is computed as described above, the target engine speed N _ETG determined by the engine control unit 20, the planetary gear unit PU The rotational speed of the first motor 3 (hereinafter referred to as “MG1 rotational speed”) N _MG1 is calculated from the proportional relationship of the gear ratio (ring gear R2, carrier CR2 and sun gear S2). so that the rotational speed N _MG1, for example, based on current value and voltage value of the inverter circuit 15, or based on the speed detected by for example the rotational speed sensor (not shown) provided in the first motor 3, the first Feedback control of the motor 3 is performed (rotational speed control).

Further, the first motor control means 25 outputs an output torque (hereinafter referred to as “MG1 torque”) T _MG1 of the first motor 3 generated to control the first motor 3 to the MG1 rotation speed _NMG1 . For example, calculation is performed from the current value / voltage value in the inverter circuit 15. At this time, if the rotation direction of the first motor 3 and the torque output direction are the same direction, output control is performed in the first motor 3 (that is, power consumption), and if it is in the opposite direction, regeneration control is performed in the first motor 3. It becomes.

Next, the second motor control means 26 determines _whether the planetary gear unit PU (the carrier CR1 and the ring gear R2, the carrier CR2 and the carrier CR2) is based on the target drive torque T _FTG , the target engine torque T _ETG, and the MG1 torque T _MG1. The proportional relationship of the gear ratio between the sun gear S1 and the sun gear S2 and the ring gear R1 and the output torque (hereinafter referred to as “MG2 torque”) of the second motor 4 so that the target drive torque _TFTG is output to the output shaft 6. _TMG2 is calculated, and the drive control of the second motor 4 is performed so as to obtain the MG2 torque _TMG2 (torque control).

Then, when the engine 2 is driven and controlled by the engine control means 20 so that the target engine speed N _ETG and the target engine torque T _ETG are _reached , the output shaft 6 (drive wheel 12) is substantially _equal to the target drive torque T _FTG . The driving torque _TO is output.

Also, for example, when the vehicle speed V is changed, such as when (the vehicle speed V is calculated on the basis of the accelerator opening Ad be constant) the engine speed _{N E} changes, the MG1 rotational speed _{N MG1} and MG2 rotational speed _{N MG2} Will change. Then, an inertia moment I _MG1 is generated in response to a change in the MG1 rotational speed N _MG1 in the rotor, the connecting shaft 3a, the sun gear S1 and the sun gear S2 of the first motor 3, and the rotor of the second motor 4 Inertia moment I _MG2 is generated in connection shaft 4a and ring gear R1 in accordance with changes in MG2 rotation speed N _MG2 . At this time, inertia torques I _MG1 × dω _MG1 and I _MG2 × dω _MG2 are generated according to the inertia moments I _MG1 and I _MG2 and the rotational angular accelerations dω _MG1 and dω _MG2 , respectively.

Therefore, when the MG2 torque T _MG2 is calculated by the second motor control means 26, the inertia torque I _MG1 × dω _MG1 and I _MG2 × dω _MG2 are corrected in the form of correcting the MG2 torque T _MG2 . controlling the second motor 4 based on the MG2 torque T _MG2 calculated in the corrected form. Thereby, even when the rotation speed change occurs in the first motor 3 and the second motor 4, torque control can be performed without deteriorating the driving feeling for the driver. When calculating the amount of inertia torque I _MG1 × dω _MG1 , it can be calculated according to the gear ratio of the ring gear R1 to the sun gear S1.

  Next, control during so-called EV traveling during traveling during stop control of the engine 2, which is a main part of the present invention, will be described. For example, when an ignition key provided in a driver's seat (not shown) is turned on, as shown in FIG. 3, the control of the hybrid vehicle control device 1 according to the present invention is started (S1).

For example, when the engine stop determination means 22 described later in detail determines that the engine 2 is stopped (No in S2), the engine control means 20 controls the engine 2 to stop. Then, as shown in FIG. 4, the target engine speed _NETG and the target engine torque _TETG are 0, and based on the target engine speed that is 0 and the rotational speed No of the output shaft 6 based on the vehicle speed V, The first motor 3 is controlled by the 1 motor control means 25, and the rotational speed is controlled so as to be the MG1 rotational speed _NMG1 (that is, the MG1 rotational speed _NMG1 is reversely rotated).

Further, the second motor control means 26 is based on the proportional relationship of the gear ratio of the planetary gear unit PU based on the target drive torque T _FTG and the MG1 torque T _MG1 of the first motor 3 whose rotational speed is controlled. The MG2 torque _TMG2 is calculated so that the target drive torque T _FTG is output to the output shaft 6, and the drive control of the second motor 4 is performed so as to be the MG2 torque _TMG2 . As a result, the drive torque To corresponding to the target drive torque _TFTG, which is the driver's required torque based on the accelerator opening degree Ad, is output to the output shaft 6.

At this time, the relationship between the MG1 torque T _MG1 , the MG2 torque T _MG2 and the driving torque To maintains the state where the engine rotational speed Ne remains 0, that is, the rotational speed of each rotational element of the planetary gear unit PU is In order not to rise, the relationship of the following formula (1) is established.

Further, the relationship between the MG1 torque T _MG1 and the MG2 torque T _MG2 is expressed by the following equation (2) from the relationship of the gear ratios of the rotating elements of the planetary gear unit PU.

なお、ａはリングギヤＲ１とキャリヤＣＲ１とのギヤ比、ｂはリングギヤＲ２とキャリヤＣＲ２とのギヤ比、ｃはサンギヤＳ２とキャリヤＣＲ２とのギヤ比である。

Here, a is a gear ratio between the ring gear R1 and the carrier CR1, b is a gear ratio between the ring gear R2 and the carrier CR2, and c is a gear ratio between the sun gear S2 and the carrier CR2.

From the relationship between the above formulas (1) and (2), the MG2 torque _TMG2 for outputting the drive torque To is calculated by the following formula (3).

Next, the limit torque of the second motor 4 for smoothly starting the engine 2 will be described. During EV travel, the limit torque calculating means 27 calculates the limit torque (motor limit torque) T _MG2 _lim of the second motor 4.

More specifically, for example, in order to start the engine 2 from a state in which the engine 2 is stopped, as shown in FIG. 5, the engine 2 does not output torque, so drag torque -Te is generated. Further, in order to raise the engine 2 to, for example, the idling speed, the engine 2, the first motor 3 (connection shaft 3 a, sun gear S 1, and sun gear S 2) and the second motor 4 (connection shaft 4 a, ring gear R 1) Therefore, inertia torques Ie × dωe, I _MG1 × dω _MG1 , and I _MG2 × dω _MG2 corresponding to the respective rotational angular accelerations are generated. Therefore, when the torque action in the engine 2, the first motor 3, and the second motor 4 when the drive torque To remains unchanged is shown based on the relationship of the gear ratios of the rotating elements of the planetary gear unit PU, the following formula ( 4).

Further, rotational angular acceleration d [omega _MG2 of the second motor 4, by replacing the relationship between the gear ratio of the rotation angle acceleration dωe of the engine 2, a relationship of Equation (5) below.

Further, rotational angular acceleration d [omega _MG1 of the first motor 3, by replacing the relationship between the gear ratio of the rotation angle acceleration dωe of the engine 2, a relationship of Equation (6) below.

  From these formulas (4), (5), and (6), the rotational angular acceleration dωe of the engine 2 is represented by the following formula (7).

That is, the drive torque To during EV traveling is proportional to the MG2 torque _TMG2 as shown in the equation (3), but as shown in the equation (7), the rotation angle of the engine 2 increases as the MG2 torque _TMG2 increases. The acceleration dωe is reduced, that is, the engine speed Ne is difficult to increase. In order to start the engine 2 smoothly, i.e. to increase the engine 2 to the idle speed within a predetermined time is required to leave a margin limits on the MG2 torque T _MG2 of the second motor 4 is there.

Here, for example, assuming that the first motor 3 outputs MG1 torque T _MG1 _max which is the maximum torque, the limit torque T _MG2 _lim of the second motor 4 is shown based on the above formula (7). The following formula (8) is established.

On the other hand, if the time for raising the engine 2 to the idle speed (for example, 800 rpm) is t (for example, 0.5 seconds), the rotational angular acceleration dωe of the engine 2 is dωe = idle speed [rpm] × 2π ÷ 60 / Since it can be obtained by t [sec], the limit torque T _MG2 _lim of the second motor 4 can be set by setting the idle speed and the time t for raising the engine 2 to the idle speed. .

Note that the drag torque -Te of the engine 2 described above changes in magnitude depending on the viscosity of the engine oil, for example, when the engine 2 is at a low temperature, that is, according to the amount of change in the drag torque -Te of the engine 2. Thus, it is preferable that the limit torque T _MG2 _lim is also corrected (see Expression (4), Expression (7), and Expression (8)).

Then, as shown in FIG. 3, during the EV running, i.e. while the by the engine control unit 20 engine 2 is controlled to stop, limits the MG2 torque _{T MG2} of the second motor 4 within the limit torque _{T MG2} _lim Every time (S3), the process returns (S6). Of course, the MG2 torque T _MG2 of the second motor 4 is output according to the target drive torque (driver required torque) T _FTG if it is within the limit torque T _MG2 _lim.

Further, since the MG2 torque T _MG2 of the second motor 4 is limited within the limit torque T _MG2 _lim, the EV traveling maximum torque To_EV output to the output shaft 6 during this EV traveling is expressed by the following equation (9). It becomes a relationship.

In the above description, what is obtained by calculating the limit torque T _MG2 _lim of the second motor 4 by the limit torque calculating means 27 has been described. However, it may be calculated in advance and provided as the limit torque map 31. . At this time, since the MG1 rotation speed N _MG1 , the MG2 rotation speed N _MG2 , and the output shaft rotation speed No change according to the vehicle speed V, the inertia torque I _MG1 × dω _MG1 , I _MG2 × dω _MG2 when starting the engine 2 is changed. Therefore, the limit torque T _MG2 _lim corresponding to the vehicle speed V (that is, the output shaft rotational speed No) is calculated and recorded in advance in the limit torque map 31. Then, by reading the limit torque _{T MG2} _lim based on the vehicle speed V, the without calculating any time, it is possible to determine the limit torque _{T MG2} _lim.

Next, a description will be given of correcting the limit torque T _MG2 _lim according to the remaining charge (SOC) of the battery 16. For example, in the case where the booster circuit is not provided in the inverter circuit 15 or the like, the voltage supplied to the first motor 3 or the second motor 4 decreases as the remaining charge of the battery 16 decreases. . That is, when the voltage supplied to the second motor 4 drops, the engine 2 is smoothly started from the second motor 4 even if the MG2 torque T _MG2 of the second motor 4 is within the limit torque T _MG2 _lim. Torque may not be output.

Therefore, the remaining charge amount of the battery 16 is detected by the remaining battery amount detection means 29, and the voltage supplied to the second motor 4 according to the detected remaining charge amount of the battery 16 (that is, the remaining charge amount decreases and is supplied to the second motor 4). The limit torque correction means 30 corrects the limit torque T _MG2 _lim calculated by the limit torque calculation means 27 so as to decrease. Thereby, it can be prevented that torque for smoothly starting the engine 2 from the second motor 4 cannot be output.

Even if the finding reads the limit torque _{T MG2} _lim than the limit torque map 31 described above, by correcting the Starring limit torque _{T MG2} _lim by similarly limited torque compensator 30, the engine from the second motor 4 It is possible to prevent the torque for smoothly starting 2 from being unable to be output.

Next, the case where the engine 2 is started will be described. During the EV travel described above, the output torque of the first motor 3 and the second motor 4 to be output according to the target drive torque (driver required torque) T _FTG by the motor torque calculation means 23, particularly the above formula (3 ), The MG2 torque T _MG2 when the engine 2 is stopped is calculated. When MG2 torque T _MG2 is calculated, MG1 torque T _MG1 is also determined based on the above formulas (1) and (2). Therefore, in the present embodiment, only MG2 torque T _MG2 is calculated. Will be described.

For example, when the MG2 torque T _MG2 calculated by the motor torque calculation means 23 during EV traveling becomes equal to or greater than the limit torque T _MG2 _lim calculated by the limit torque calculation means 27, that is, the engine 2 is smoothly driven by the second motor 4. Since the engine cannot be started, the engine start determination 21 determines that the engine 2 is started. Based on this determination, the engine control means 20 controls the engine 2 to start (Yes in S2). This not be MG2 torque _{T MG2} of the second motor 4 is the limiting torque _{T MG2} _lim above, the engine 2 is smoothly started.

In a state where the engine 2 is started, that is, in a state where the engine 2 is running while the engine 2 is being driven, the MG2 torque T _MG2 is equal to or greater than the limit torque T _MG2 _lim, that is, the driver request torque T _FTG is the maximum EV running Since it is larger than the torque To_EV (Yes in S4), the process returns as it is (S6).

Next, a case where the engine 2 is stopped will be described. Even in the state of traveling while the engine 2 is being driven, the target torque (driver request) when the engine 2 is stopped by the motor torque calculation means 23 (that is, assuming that the engine 2 is stopped). Torque) MG2 torque T _MG2 to be output is calculated according to T _FTG .

Thus, when the MG2 torque T _MG2 calculated by the motor torque calculating means 23 is within the limit torque T _MG2 _lim calculated by the limit torque calculating means 27, that is, the driver required torque T _FTG is greater than the EV traveling maximum torque To_EV. Since the engine 2 can be smoothly started by the second motor 4 even immediately after the engine 2 is stopped, for example, the engine stop determination 22 determines that the engine 2 is stopped (S5). Based on this determination, the engine control means 20 controls to stop the engine 2 and returns (S6). This not be MG2 torque _{T MG2} of the second motor 4 is the limiting torque _{T MG2} _lim above, always the engine 2 is smoothly started. Thereafter, during the traveling of the hybrid vehicle, the control shown in FIG. 3 is repeatedly performed by the control device 1 of the hybrid vehicle.

As described above, according to the control apparatus 1 for a hybrid vehicle according to the present invention, the motor control unit 24 leaves a surplus power for smoothly starting the engine 2 during the stop control of the engine 2 by the engine control unit 20. Since the second motor 4 is driven and controlled within the limited torque T _MG2 _lim, when the engine 2 is started, for example, the engine 2 can be smoothly operated without lowering the output torque of the first motor 3 and the second motor 4 once. It is possible to prevent the driver from feeling uncomfortable.

The motor control means 24, for example, the limit torque _{T MG2} without calculating any time _lim, that controls the driving of the second motor 4 within the limit torque _{T MG2} _lim read than the limit torque map 31 based on the vehicle speed V Therefore, when starting the engine 2, the engine 2 can be started smoothly, thereby preventing the driver from feeling uncomfortable.

Furthermore, since the motor control means 24 can drive and control the second motor 4 within the limit torque T _MG2 _lim calculated by the limit torque calculation means 27 as needed, when starting the engine 2, the motor 2 is controlled. It is possible to start smoothly, thereby preventing the driver from feeling uncomfortable.

Further, the limit torque calculation means 27 calculates the engine rotation angular acceleration dωe when the engine 2 is started by the MG2 torque T _MG2 of the second motor 4 that is driven and controlled by the second motor control means 26, and the calculation is performed. Since the motor limit torque T _MG2 _lim is calculated based on the engine rotation angular acceleration dωe, the engine rotation angular acceleration dωe when the engine 2 is started by the first motor 3 and the second motor 4 is smoothly started. Thus, the engine rotational angular acceleration dωe can be set to be smooth, whereby the engine 2 can be started smoothly, and the driver can be prevented from feeling uncomfortable.

Furthermore, since the limit torque correction unit 30 corrects the limit torque T _MG2 _lim according to the remaining charge of the battery 16 detected by the remaining battery level detection unit 29, for example, the remaining charge of the battery 16 decreases. Thus, even when the voltage supplied to the second motor 4 drops and the torque that can be output from the second motor 4 becomes low, the torque for smoothly starting the engine 2 cannot be output from the second motor 4. Can be prevented. Thereby, when starting the engine 2, the engine 2 can be started smoothly, thereby preventing the driver from feeling uncomfortable.

The driver request torque detection means 28 detects the driver request torque T _FTG requested by the driver, and the motor torque calculation means 23 calculates the MG2 torque T _MG2 of the second motor 4 based on the driver request torque T _FTG to start the engine. When the determining means 21 determines that the MG2 torque T _MG2 calculated by the motor torque calculating means 23 is equal to or greater than the motor limit torque T _MG2 _lim calculated by the limit torque calculating means 27, the engine control means 20 However, since the engine 2 is controlled to start based on the determination result of the engine start determination means 21, the engine 2 can be started before the second motor 4 exceeds the motor limit torque T _MG2 _lim. It can start smoothly and give the driver a sense of incongruity Can be prevented.

Further, when the MG2 torque T _MG2 of the second motor 4 calculated by the motor stop calculating means 22 by the motor torque calculating means 23 is within the motor limit torque T _MG2 _lim calculated by the limit torque calculating means 27, the engine 2 determining a stop, the engine control unit 20 stops controlling the engine 2 based on the determination result of the engine stop determination unit 22, when stopping the engine 2, the MG2 torque T _MG2 of the second motor 4 motor limit torque T _MG2 can be less than _lim, whereby for example be the starting of the engine 2 is performed immediately after, to be able to start the engine 2 smoothly, it is possible to prevent discomfort to the driver.

In the present embodiment, the limit torque T _MG2 _lim of the second motor 4 is calculated and the second motor 4 during EV traveling is controlled within the limit torque T _MG2 _lim. not only, (see equation (1) and (2)) and the MG1 torque _{T MG1} of the first motor 3 from the proportional relationship between the MG2 torque _{T MG2} of the second motor 4, it calculates a limit torque of the first motor 3 Even if the first motor 3 during EV travel is controlled within the limit torque, the same control is possible.

  In the control of the transmission 10 described above, the first motor control means 32 controls the rotation speed of the first motor 3 and the second motor control means 33 controls the torque of the second motor 4. On the contrary, the second motor control means 33 may control the rotation speed of the second motor 4 and the first motor control means 32 may control the torque of the first motor 3.

  Further, in the hybrid mechanism 20 described above, a so-called Simpson type planetary gear unit PU has been described. However, for example, a Ravigneaux type planetary gear unit may be used, and further, for example, two planetary gears may be used. There may be, that is, any engine that has four rotating elements and is connected to the engine, the first motor, the second motor, and the output shaft respectively connected to the four rotating elements. It may be a thing.

  Further, in the present hybrid mechanism 20, the example provided with the differential gear mechanism (planetary gear unit PU) having four rotating elements as described above has been described as an example. In addition to connecting the engine, the first motor, the second motor, and the output shaft to each of the two rotating elements, the present invention may be used for a hybrid mechanism in which, for example, a brake is connected to the fifth rotating element. . Further, for example, the present invention may be used for a hybrid mechanism including a differential gear mechanism having six rotating elements, that is, a differential gear mechanism having at least four or more rotating elements is provided. The present invention may be used for any hybrid mechanism.

The block diagram which shows the control apparatus of the hybrid vehicle which concerns on this invention. The skeleton figure which shows the hybrid vehicle which concerns on this invention. The flowchart which shows control of the control apparatus of a hybrid vehicle. Explanatory drawing which shows the torque relationship of an engine, a 1st motor, a 2nd motor, and an output shaft when a rotation speed does not change. Explanatory drawing which shows the torque relationship of an engine, a 1st motor, a 2nd motor, and an output shaft when a rotation speed changes.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hybrid vehicle control apparatus 2 Engine 3 1st motor 4 2nd motor 5 Input shaft 6 Output shaft 12 Drive wheel 20 Engine control means 21 Engine start determination means 22 Engine stop determination means 23 Motor torque calculation means 24 Motor control means 25 First 1 motor control means 26 second motor control means 27 limit torque calculation means 28 driver requested torque detection means 29 battery remaining amount detection means 30 limit torque correction means 31 limit torque map PU differential gear mechanism (planetary gear unit)
S1 Rotating element (sun gear)
S2 Rotating element (sun gear)
CR1 Rotating element (carrier)
CR2 Rotating element (carrier)
R1 Rotating element (ring gear)
R2 Rotating element (ring gear)
N _MG1 First motor speed T _MG1 First motor output torque T _MG2 Second motor output torque T _MG2 _lim Motor limit torque T _FTG driver required torque dωe Engine rotation angular acceleration dω _MG1 first motor rotation angular acceleration dω _MG2 second motor rotation angular acceleration V Vehicle speed

Claims (6)

An input shaft connected to the engine, a first motor, a second motor, an output shaft connected to the drive wheel, and the input shaft, the first motor, the second motor, and the output shaft are connected to each other. A differential gear mechanism having four rotating elements, and a hybrid vehicle including
An engine control means capable of driving and controlling the engine; and a motor control means capable of controlling and driving the first motor and the second motor so that the engine can be stopped and the hybrid vehicle can run. In a hybrid vehicle control device capable of driving and controlling the first motor and the second motor and starting the engine by driving and controlling the first motor and the second motor,
The motor control means includes first motor control means capable of controlling the rotational speed of the first motor during stop control of the engine, and second motor control capable of torque-controlling the output torque of the second motor. Means,
The motor control means includes the first motor and the second motor during the engine stop control by the engine control means within the motor limit torque that leaves a surplus power for smoothly starting the engine . 2 motor will be driven and controlled,
The motor limit torque includes the drag torque of the engine, the torque of the first motor, and the engine, the first motor, and the second motor when the engine is started with the maximum torque of the first motor. A value that can be calculated from the inertia torque, and is set to a value that can start the engine at an engine rotational angular velocity for increasing the engine speed to an idle speed within a predetermined time.
A control apparatus for a hybrid vehicle characterized by the above. A limit torque map in which the motor limit torque corresponding to the vehicle speed is recorded;
The motor control means drives and controls the second motor within the motor limit torque read from the limit torque map based on the vehicle speed.
The control device for a hybrid vehicle according to claim 1. Limit torque calculating means for calculating the motor limit torque as needed,
The motor control means drives and controls the second motor within the motor limit torque calculated by the limit torque calculation means.
The control device for a hybrid vehicle according to claim 1. A battery freely chargeable / dischargeable with respect to the first motor and the second motor;
Battery remaining amount detecting means capable of detecting the remaining amount of charge of the battery;
Limit torque correction means for correcting the motor limit torque in accordance with the remaining charge amount of the battery detected by the battery remaining amount detection means,
The control device for a hybrid vehicle according to any one of claims 1 to 3 . A driver request torque detecting means for detecting a driver request torque requested by the driver;
Motor torque calculation means for calculating output torques of the first motor and the second motor in a state where the engine is stopped based on the driver request torque;
Output torque before Symbol second motor state of stopping the engine computed by the motor torque calculating means, when the at motor limit torque or more, and a engine start judging means for judging the start of the engine Prepared,
The engine control means is configured to start the engine based on a determination result of the engine start determination means.
The control apparatus of the hybrid vehicle in any one of Claims 1 thru | or 4 . Output torque before Symbol second motor state of stopping the engine computed by the motor torque calculating means, when the is within the motor limit torque, an engine stop determination means for determining a stop of the engine,
The engine control unit is configured to stop the engine based on a determination result of the engine stop determination unit.
The control device for a hybrid vehicle according to claim 5 .

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