JP4218683B2 - Control device for hybrid drive - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a controller of a hybrid driving device for suppressing the fluctuation of a driving force which is generated during startup of an engine leading to operation disturbance. <P>SOLUTION: A vehicle driving torque control part 66 limits vehicle driving torque received from a vehicle driving torque determining part 64, and outputs it to an adding part 68 so that predetermined limit torque corresponding to the operating circumstances of an engine received from an engine starting part 60 can not be exceeded. An adding part 68 applies a torque command calculated by adding a reaction force offset torque to be output from a reaction force offset torque determination part 62 and a vehicle driving torque after limitation in a vehicle driving torque limiting part 66 to a PCU 45, and generates torque corresponding to a torque command from a second motor generator. Even when any reaction force is generated according to the start of the engine, the second motor generator is able to further generate torque enough to offset the reaction force. <P>COPYRIGHT: (C)2007,JPO&amp;INPIT

Description

  The present invention relates to a control device for a hybrid drive device, and more particularly to engine start control of a hybrid drive device including an engine and a motor generator as a power source.

  In recent years, hybrid vehicles using both the engine and the motor as power sources have been proposed in order to reduce the fuel consumption of the engine. Various systems such as a series system and a parallel system have been proposed for such hybrid vehicles, but a series-parallel hybrid system in which an engine and two motor generators are connected by a planetary gear mechanism. Has been proposed. In such a series-parallel hybrid system, the centrifugal force of the engine and motor power is controlled by the power split mechanism configured by the planetary gear mechanism.

  In particular, in such a hybrid drive device, a configuration has been proposed in which the engine is started by rotationally driving the engine via a distribution mechanism by one of the motor generators. In such a configuration, since a starter dedicated to starting is not required, the number of parts is reduced and the apparatus is inexpensive.

  Further, Japanese Patent Application Laid-Open No. 09-170533 (Patent Document 1) discloses a second motor in order to suppress fluctuations in the driving force of the vehicle due to a reaction force generated when the engine is started by the first motor generator. It has been proposed to control the generator so as to generate a torque that cancels out fluctuations in the driving force of the vehicle (hereinafter also referred to as “reaction force canceling torque”).

Japanese Patent Application Laid-Open No. 2000-324607 (Patent Document 2) is provided with a torque sensor for detecting rotational torque on a transmission path for transmitting power from the engine to the drive shaft. Based on this, it has been proposed to perform control so as to compensate for torque output to the drive shaft.
JP 09-170533 A JP 2000-324607 A

  However, in the engine start control disclosed in Patent Document 1, the reaction force canceling torque is not particularly reflected in the determination of the output torque in the second motor generator that generates the reaction force canceling torque. Assuming that the output torque can be set within the possible generation range of the second motor generator as a general control configuration, the second motor generator is outputting a torque that is almost close to the possible torque (rated torque). In some cases, the reaction force canceling torque cannot be added and generated. For this reason, there has been a case where the driving force is reduced due to the reaction force accompanying the engine start even though the driver steps on the accelerator and gives an acceleration command.

  Also in the engine start control disclosed in Patent Document 2, the reaction force canceling torque is not particularly reflected in the determination of the output torque in the second motor generator, and the same problem may occur.

  The present invention has been made to solve such problems, and an object of the present invention is to suppress fluctuations in driving force that occur at the time of engine start or the like, which is a driving disturbance, in a hybrid drive device. It is providing the control apparatus of a hybrid drive device.

  According to the present invention, an engine that operates by fuel combustion, a power split mechanism that mechanically distributes the output of the engine to the first motor generator and the output member, and a rotational force is applied between the output member and the drive wheels. It is a control apparatus of a hybrid drive device provided with a 2nd motor generator. The control device for the hybrid drive device according to the present invention includes a starter for starting the engine by rotating the engine through a power split mechanism by a first motor generator according to a traveling state, and an engine by the starter Reaction force canceling torque determining means for determining a reaction force canceling torque for canceling fluctuations in driving force due to starting of the vehicle, and vehicle driving for determining a vehicle driving torque to be generated by the second motor generator according to the running state The torque determining means and the limit torque obtained by subtracting a predetermined margin torque from the torque that can be generated by the second motor generator in a period during which the engine can be started upon receiving the vehicle driving torque determined by the vehicle driving torque determining means. Vehicle driving torque limiting means for limiting the vehicle driving torque and reaction force canceling torque determining means And second motor generator control means for controlling the second motor generator so that a torque obtained by adding the reaction force canceling torque determined in step 2 and the vehicle driving torque after being restricted by the vehicle driving torque restriction means is generated. .

  According to the control apparatus for a hybrid drive apparatus according to the present invention, the vehicle drive torque limiting means does not exceed the limit torque obtained by subtracting the predetermined margin torque from the torque that can be generated by the second motor generator in a period during which the engine can be started. Thus, the vehicle driving torque is limited. Therefore, the second motor generator can further generate a reaction force canceling torque for canceling the driving force fluctuation caused by the engine starting, regardless of the vehicle driving torque generated at the time of starting the engine.

  Preferably, the surplus torque corresponds to the maximum reaction force cancellation torque determined by the reaction force cancellation torque determination means.

  Preferably, the surplus torque is set to a torque that can cancel the maximum value of the driving force fluctuation caused by the engine start.

  Preferably, the vehicle drive torque limiting means gradually increases the margin torque to substantially zero according to the engine starting process.

  Preferably, the vehicle drive torque limiting means sets the margin torque to zero during operation of the engine.

  Preferably, the starting means starts the engine when the vehicle driving torque to be generated by the second motor generator exceeds the limit torque.

  According to the present invention, it is possible to realize a control device for a hybrid drive device that can suppress fluctuations in drive force that occur when the engine is started, which becomes a driving disturbance.

  Embodiments of the present invention will be described in detail with reference to the drawings. Note that the same or corresponding parts in the drawings are denoted by the same reference numerals and description thereof will not be repeated.

FIG. 1 is a schematic configuration diagram of a hybrid vehicle according to an embodiment of the present invention.
Referring to FIG. 1, a hybrid vehicle (hereinafter also simply referred to as “vehicle”) includes a hybrid drive device 10, a control device 20, a differential gear 30, wheels (drive wheels) 50, an accelerator pedal 150, And a shift lever 152.

  The hybrid drive device 10 generates a driving force for the vehicle. A more detailed description of the hybrid drive device 10 will be described later. The driving force generated by the hybrid drive device 10 is transmitted to the wheel 50 via the differential gear 30 and used for rotationally driving the wheel 50. The differential gear 30 absorbs a difference in rotation between the left and right wheels 50 using a resistance difference from the road surface.

  The control device 20 is configured by an electronic control unit (ECU) including a CPU, a memory area including a RAM, a ROM, and the like, and operates a vehicle on which the hybrid drive device 10 is mounted according to a driver's instruction. In order to control the overall operation of the devices and circuits mounted on the vehicle, the amount of depression of the accelerator pedal 150 and the shift position (position) of the shift lever 152 that change according to the driver's operation are sequentially monitored. To do.

  One shift lever 152 is selected from a plurality of shift positions according to the driver's operation (shift lever operation). The plurality of shift positions include, for example, a parking position (P position) when the vehicle stops, a reverse position (R position) when the vehicle moves backward, a neutral position (N position), and a drive position (D position) when the vehicle moves forward. included. In addition to the drive position (D position), subdivided drive positions (for example, 4 positions, 3 positions, 2 positions, L positions, etc.) that limit the number of shiftable gear positions may be provided.

  The hybrid drive device 10 includes an engine 112 such as an internal combustion engine that operates by combustion of fuel, a spring-type damper device 114 that absorbs rotational fluctuations of the engine 112, and an engine 112 that is transmitted via the damper device 114. A planetary gear type power split mechanism 120 that mechanically distributes the output to the first motor generator 116 and the output member 118 and a second motor generator 122 that applies a rotational force to the output member 118 are provided.

  The engine 112, the damper device 114, the power split mechanism 120, and the first motor generator 116 are coaxially arranged in the axial direction, and the second motor generator 122 is arranged on the outer peripheral side of the damper device 114 and the power split mechanism 120. Arranged concentrically.

  The power split mechanism 120 is a single-pinion type planetary gear device, which is a sun gear 120s connected to the motor shaft 124 of the first motor generator 116 as three rotating elements, a carrier 120c connected to the damper device 114, and a second Ring motor 120r connected to rotor 122r of motor generator 122 is included.

  The output member 118 is integrally fixed to the rotor 122r of the second motor generator 122 with a bolt or the like, and is connected to the ring gear 120r of the power split mechanism 120 via the rotor 122r. The output member 118 is provided with an output gear 126, and the bevel gear type differential gear 30 is decelerated and rotated through the large gear 130 and the small gear 132 of the intermediate shaft 128, and the power is distributed to each wheel 50. The

  The first motor generator 116 and the second motor generator 122 are electrically connected to a power storage device (battery) 40 via a PCU (Power Control Unit) 45. The first motor generator 116 and the second motor generator 122 are each supplied with electric energy from the power storage device 40 and are rotationally driven with a predetermined torque, and rotational braking (electric braking torque of the motor generator itself). ), The operation can be switched between a charged state in which the power storage device 40 functions as a generator and charges electric energy in the power storage device 40 and a no-load state in which the motor shaft 124 and the rotor 122r are allowed to freely rotate.

  The power storage device 40 is a chargeable / dischargeable DC power supply device, and is composed of, for example, a secondary battery such as nickel metal hydride or lithium ion.

  PCU 45 includes a power converter that converts DC power supplied from power storage device 40 into drive power to first motor generator 116 and second motor generator 122. Then, the PCU 45 controls the voltage, frequency, phase, and the like of AC power applied to the first motor generator 116 and the second motor generator 122, respectively, according to the torque command received from the control device 20. The PCU 45 can also convert AC power generated by the first motor generator 116 or the second motor generator 122 into DC power and supply it to the power storage device 40. The first motor generator 116 and the second motor generator It is also possible to exchange electric power with 122.

  The engine 112 has its fuel injection amount, throttle valve opening, ignition timing (start command), and the like controlled by the control device 20, so that its operating state such as its rotational speed and torque is controlled. The PCU 45 is also controlled by the control device 20.

  That is, the control device 20 executes a processing routine in accordance with a preset program, so that the driving modes of the engine 112, the first motor generator 116, and the second motor generator 122 are changed according to the driving situation. Switching between running and engine / motor running. The traveling state includes the accelerator depression amount by the driver, the shift position, the state of charge (SOC) of the power storage device 40, and the like.

  For example, in motor traveling, the vehicle travels using only the second motor generator 122 as a power source with the first motor generator 116 in a no-load state and the second motor generator 122 in a rotationally driven state. In charge running, the first motor generator 116 functions as a generator, and the first motor generator 116 causes the power storage device 40 to run while only the engine 112 is driven with the second motor generator 122 in a no-load state. Charged. Alternatively, in engine / motor traveling, the first motor generator 116 functions as a generator, while the first motor generator 116 charges the power storage device 40 while traveling using both the engine 112 and the second motor generator 122 as power sources. Is done.

  Further, regenerative braking control is performed by causing the second motor generator 122 to function as a generator when the motor is running, and the first motor generator 116 is functioned as a generator and the engine 112 is operated when the vehicle is stopped. Charging control for charging power storage device 40 by motor generator 116 is also performed by control device 20.

  As described above, in the hybrid vehicle, the engine 112 is automatically stopped when the vehicle is stopped, while the start timing is controlled by the control device 20 according to the traveling state.

  Specifically, the driving force by the second motor generator 122 without starting the engine 112 in order to avoid a region where the engine efficiency is low, such as when starting, when driving at a low speed, or at a light load such as when going down a gentle hill. Drive on. The engine 112 is started when the driving situation requires a certain level of driving force. However, when the engine 112 needs to be driven for warming up or the like, the engine 112 is started in a no-load state at the time of starting and is driven at idling rotational speed until a desired warming up is realized. The engine 112 is also started when performing the above charging control when the vehicle is parked.

  In hybrid drive device 10 according to the embodiment of the present invention, when engine 112 is started, first motor generator 116 is driven as an electric motor in accordance with a torque command from control device 20. Then, the ring gear 120r of the power split mechanism 120 becomes a reaction force element, and the torque of the first motor generator 116 is transmitted to the engine 112 via the motor shaft 124, the carrier 120c and the damper device 114, and the engine 112 is cranked (rotation driven). ) Along with the cranking of the engine 112, fuel is injected and ignited according to a command from the control device 20, and the self-sustaining rotation of the engine 112 is established. When the self-rotation of the engine 112 is established, torque from the engine 112 is transmitted to the output member 118 through the damper device 114, the carrier 120c, and the ring gear 120r. The torque of the output member 118 is transmitted to the wheels 50 through the output gear 126, the large gear 130, the small gear 132, and the differential gear 30 to generate a driving force.

  Thus, in the hybrid drive device 10 according to the embodiment of the present invention, the engine 112 is started by the first motor generator 116, thereby eliminating the need for a starter dedicated to starting, reducing the number of parts, and the device. It will be cheap.

  On the other hand, as described in Patent Document 1, when the engine 112 is rotationally driven by the first motor generator 116 via the power split mechanism 120, the reaction force is exerted on the output member 118 by the rotational resistance (friction or the like) of the engine 112. The engine output or the output torque of the first motor generator 116 may act on the output member 118 as the engine 112 starts. When such a phenomenon occurs, the driving force fluctuation that causes driving disturbance occurs in the vehicle, which may impair driving performance.

  Therefore, it is known that when the engine 112 is started, torque control of the second motor generator 122 is performed in addition to the first motor generator 116 so as not to cause fluctuations in the driving force that cause driving disturbance. Specifically, the engine 112 is driven to rotate by the first motor generator 116, and a reaction force canceling torque is generated from the second motor generator 122 so as to cancel the driving force fluctuation generated by the reaction force.

  FIG. 2 is a diagram for explaining conventional engine start control for generating reaction force canceling torque. With reference to FIG. 2, a case where the driver depresses the accelerator pedal 150 during motor traveling will be described.

  FIG. 2 (a) is a diagram showing a change in the accelerator operation over time by the driver. As an example, FIG. 2A shows a case where the driver steps down to a certain depression amount with a certain rate of change.

  FIG. 2B is a diagram showing a change over time in the vehicle drive torque requested by the control device 20 to the second motor generator 122. The control device 20 can generate a torque command according to the accelerator depression amount (rated rating). Torque) at a constant rate of change.

  FIG. 2 (c) is a diagram showing a change over time in the rotational speed of the engine 112. As an example, if the engine start condition is that the torque command for the second motor generator 122 exceeds the torque that can be generated by the second motor generator 122, the first motor generator 116 is driven as an electric motor at time t1, and the engine 112 is driven. Crank.

  FIG. 2 (d) is a diagram showing the change over time of the reaction torque accompanying the start of the engine 112. The direction in which the vehicle is driven, that is, the direction of the vehicle driving torque generated by the second motor generator 122 is defined as “positive”. The reaction force generated by the engine 112 is generated in proportion to the rate of change of the rotational speed of the engine 112 (time differential value of the engine rotational speed). Therefore, as the rotational speed of the engine 112 increases, the reaction torque increases in the “negative” direction. Arise.

  FIG. 2 (e) is a diagram showing a change with time of torque generated by the second motor generator 122. Since the delay time until the voltage, frequency, phase, etc. of the AC power supplied by the PCU 45 is changed in response to the torque command from the control device 20 is negligibly small, the torque generated by the second motor generator 122 is controlled. The torque command determined by the device 20 is followed (MG2 generated torque). On the other hand, if an engine start request is generated at time t1, and the engine 112 has established a self-sustaining rotation at time t2, reaction torque from the engine 112 shown in FIG. 2 (d) is generated at time t1 to t2. Therefore, torque obtained by subtracting the reaction torque from the torque generated by second motor generator 122 is output from power split mechanism 120 to output member 118 as the driving torque of the vehicle (MG2 effective torque). That is, the vehicle driving torque output from the second motor generator 122 increases monotonously from time t1 until the driver starts stepping on the accelerator, but during the period from time t1 to time t2, the engine 112 is started. It is substantially reduced by the reaction force that accompanies this.

  FIG. 2 (f) is a diagram showing a change in vehicle acceleration over time. As described above, as the vehicle driving torque output from the second motor generator 122 substantially decreases, a region 80 where the vehicle acceleration decreases occurs. As a result, the driver may experience drivability degradation such as a decrease in vehicle acceleration despite the depression of the accelerator, or a shock due to a decrease in vehicle acceleration once increased.

  Therefore, in control device 20 according to the embodiment of the present invention, a torque command is given to second motor generator 122 so as to suppress such drivability deterioration and occurrence of shock.

  FIG. 3 is a control block diagram for realizing engine start control in the control device 20.

  Referring to FIG. 3, control device 20 includes an engine starting unit 60, a reaction force canceling torque determining unit 62, a vehicle driving torque determining unit 64, a vehicle driving torque limiting unit 66, and an adding unit 68.

  The engine starting unit 60 and the vehicle driving torque determining unit 64 receive the driving state such as the depression amount of the accelerator pedal 150, the shift position of the shift lever 152, the charging state of the power storage device 40, etc. A process for determining the vehicle driving torque for the generator 122 is executed.

  Specifically, the engine starting unit 60 is starting from the outside and is completed when the amount of depression of the accelerator pedal 150 exceeds a predetermined value or when the state of charge of the power storage device 40 falls below a predetermined value. -The engine 112 is started according to the operating state of the engine 112 such as when it is stopped. When starting the engine 112, the engine starter 60 gives the PCU 45 a torque command for outputting a torque necessary for cranking the engine 112, thereby rotating the first motor generator 116.

  Further, the vehicle drive torque determination unit 64 determines a positive vehicle drive torque for causing the second motor generator 122 to function as an electric motor according to the depression amount of the accelerator pedal 150, while the accelerator pedal 150 is depressed. When there is no brake pedal or when a brake pedal (not shown) is depressed, a negative vehicle driving torque for causing the second motor generator 122 to function as a generator is determined and output to the vehicle driving torque limiting unit 66.

  The reaction force canceling torque determination unit 62 monitors the torque command for the first motor generator 116 output from the engine starting unit 60 and calculates a reaction force that can be generated in the power split mechanism 120 when the engine 112 is started. As an example, the reaction force canceling torque determination unit 62 regards a torque obtained by multiplying a torque command for the first motor generator 116 by a predetermined conversion coefficient as a reaction force. Further, the conversion coefficient may be changed depending on the temperature, the vehicle speed (the rotation speed of the second motor generator 122), and the like. Then, the reaction force canceling torque determining unit 62 determines a value having the same absolute value as the calculated reaction force and having the opposite sign as the reaction force canceling torque, and outputs it to the adding unit 68.

  The vehicle drive torque limiting unit 66 limits the vehicle drive torque received from the vehicle drive torque determination unit 64 and outputs the limit to the addition unit 68 so as not to exceed a predetermined limit torque according to the operation state of the engine 112 received from the outside. To do. Specifically, the vehicle drive torque limiter 66 determines a limit torque by subtracting a surplus torque according to the operating state of the engine 112 from the torque that can be generated by the second motor generator 122, and adds the limit torque to the adder 68. The maximum value of the vehicle driving torque that can be given to Then, the vehicle drive torque limiting unit 66 sets the maximum reaction force canceling torque determined by the reaction force canceling torque determining unit 62 as a surplus torque during a period in which the engine 112 can be started, and during the engine 112 starting process. Accordingly, the surplus torque is asymptotically approached to zero. Further, the vehicle drive torque limiting unit 66 sets the surplus torque to zero while the engine 112 is operating. Here, it is desirable that the surplus torque is equal to or greater than the torque that can cancel the maximum value of the driving force fluctuation caused by the start of the engine 112. Note that such a maximum value of the driving force fluctuation can be obtained experimentally in advance.

  In the embodiment of the present invention, as an example, a case where the drive torque supplied from the vehicle drive torque determination unit 64 exceeds the limit torque is one of the start conditions of the engine 112. Therefore, when the drive torque given from vehicle drive torque determining unit 64 exceeds the limit torque, vehicle drive torque limiting unit 66 gives an engine start request to engine start unit 60, and engine start unit 60 In response to the engine start request received from 66, the engine 112 is started.

  The adding unit 68 provides the PCU 45 with a torque command obtained by adding the reaction force canceling torque output from the reaction force canceling torque determining unit 62 and the vehicle driving torque after being limited by the vehicle driving torque limiting unit 66 to the second PCU 45. Torque corresponding to the torque command is generated from the motor generator 122.

  Thus, during the period when engine 112 can be started, vehicle drive torque limiting unit 66 causes vehicle drive torque generated by second motor generator 122 to be equal to or less than the limit torque obtained by subtracting the margin torque from the outputtable torque. Therefore, the second motor generator 122 has a margin (margin) corresponding to the margin torque. Therefore, even if a reaction force is generated as the engine 112 is started, the second motor generator 122 can further generate a torque sufficient to cancel the reaction force, and thus is output from the second motor generator 122. It can suppress that vehicle drive torque (torque transmitted to the wheel 50) reduces substantially.

FIG. 4 is a diagram for illustrating engine start control according to the embodiment of the present invention.
With reference to FIG. 4, the control when the driver steps on the accelerator when the motor is running will be described as in FIG. 2 described above.

  FIG. 4A is a diagram illustrating a change in the accelerator operation over time by the driver. As an example, FIG. 4A illustrates a case where the driver steps down to a certain depression amount with a certain rate of change.

  FIG. 4B is a diagram showing the time change of the vehicle driving torque output from the vehicle driving torque determining unit 64 and the vehicle driving torque after being limited by the vehicle driving torque limiting unit 66. The vehicle drive torque determination unit 64 increases the vehicle drive torque to a torque that can be generated at a constant rate of change according to the depression amount of the accelerator pedal 150. On the other hand, the vehicle drive torque limiter 66 is the maximum counterbalance determined by the reaction force canceling torque determination unit 62 from the torque that can be generated by the second motor generator 122 during a period when the engine 112 is stopped, that is, the engine 112 can be started. The vehicle drive torque is limited so as not to exceed the limit torque obtained by reducing the force canceling torque (margin torque). Therefore, after time t1, the vehicle driving torque output from the vehicle driving torque determination unit 64 is maintained below the limit torque.

  In addition, vehicle drive torque limiting unit 66 generates an engine start request at time t1, and engine start unit 60 starts engine 112 in response to the engine start request.

  FIG. 4C is a diagram showing a change over time in the rotational speed of the engine 112. As described above, when an engine start request is generated at time t1, engine start unit 60 drives first motor generator 116 as an electric motor, and cranks engine 112.

  FIG. 4 (d) is a diagram showing the change over time of the reaction torque accompanying the start of the engine 112. The reaction force by the engine 112 is generated in proportion to the rate of change of the rotational speed of the engine 112 (time differential value of the engine rotational speed). Therefore, as the rotational speed of the engine 112 by the first motor generator 116 increases, Reaction torque is generated in the direction. At the same time, the reaction force canceling torque determining unit 62 determines the reaction force canceling torque in accordance with the torque command output from the engine starting unit 60.

  FIG. 4 (e) is a diagram showing a change with time of torque generated by the second motor generator 122. A torque command obtained by adding the limited vehicle driving torque output from the vehicle driving torque limiting unit 66 and the reaction force canceling torque output from the reaction force canceling torque determining unit 62 is output to the PCU 45, and the second motor generator 122 Then, torque corresponding to the torque command is generated (MG2 generated torque). For example, if starting of the engine 112 is started at time t1 and self-sustained rotation is established at time t2, the torque equal to the limited vehicle driving torque output from the vehicle driving torque limiting unit 66 at time t1 to t2. Is substantially output from the second motor generator 122 to the output member 118 (MG2 effective torque).

  FIG. 4F is a diagram illustrating a change in vehicle acceleration over time. As described above, the vehicle driving torque (MG2 effective torque) output from the second motor generator 122 is maintained at a certain value or less at times t1 to t2, which is the starting process of the engine 112, so that the accelerator pedal is depressed. Although the acceleration cannot be increased in accordance with the amount, the acceleration does not decrease, so that the drivability and the occurrence of shock can be suppressed. Note that after the start of the engine 112 is completed, the driving torque from the engine 112 is applied, so that the acceleration increases significantly.

  Referring to FIG. 4B again, the vehicle drive torque limiting unit 66 reduces the margin torque so as to gradually approach zero after time t3 after completion of starting of the engine 112 (time t2). In other words, vehicle drive torque limiter 66 gradually increases the limit torque to a torque that can be generated by second motor generator 122. After time t4, vehicle drive torque limiting unit 66 sets the margin torque to zero, that is, sets the limit torque as the torque that can be generated by second motor generator 122.

  Referring to FIG. 4E again, as described above, after time t3, vehicle driving torque limiting unit 66 relaxes the limiting torque, so that the driving torque generated by second motor generator 122 increases. The increased amount is used as the driving torque of the vehicle. This is because it is not necessary to cancel the reaction force generated at the start of the engine 112 when the engine 112 is started. As a result, the torque that can be generated by the second motor generator 122 can be effectively used as the drive torque.

  When the engine 112 is stopped according to the traveling state, the vehicle drive torque limiting unit 66 changes the surplus torque from zero to the maximum reaction force canceling torque determined by the reaction force canceling torque determining unit 62 described above. . Here, the engine stop condition is that the drive torque required for the vehicle (the torque required for the wheels 50) is at least equal to or less than the torque obtained by subtracting the marginal torque from the torque that can be generated by the second motor generator 122. Thus, at the stop timing of the engine 112, the drive torque output from the vehicle drive torque determination unit 64 is equal to or less than the changed limit torque. Therefore, the occurrence of a shock due to a sudden change in the torque generated by the second motor generator 122 can be avoided without limiting the vehicle driving torque in accordance with the change of the margin torque in the vehicle driving torque limiting unit 66.

  In the above description, the case where the marginal torque is gradually approached to zero after the start of the engine 112 has been described, but the marginal torque may be reduced while the engine 112 is starting. Referring to FIG. 4D again, after the cranking of engine 112 is started (time t1), the reaction torque increases to a maximum value and then decreases. Therefore, in the starting process of the engine 112, the margin torque may be gradually reduced after the reaction force torque starts to decrease.

  The function of the control block diagram shown in FIG. 3 described above may be configured in the control device 20 so as to include a circuit corresponding to each block, but in many cases, the control device 20 performs a processing routine according to a preset program. It is realized by executing.

  FIG. 5 is a diagram showing a processing routine for realizing engine start control corresponding to the block diagram shown in FIG.

  Referring to FIG. 5, control device 20 acquires a traveling state from the outside (step S <b> 100). Then, after determining the vehicle driving torque for second motor generator 122 (step S102), control device 20 determines which operating state of engine 112 is (step S104).

  When engine 112 is stopped (in the case of “stopped” in step S104), control device 20 sets the maximum reaction force canceling torque determined by reaction force canceling torque determining unit 62 as the surplus torque, and the limit torque Is changed (step S106). Then, control device 20 determines whether or not the vehicle drive torque for second motor generator 122 exceeds the limit torque (step S108). If the limit torque is exceeded (YES in step S108), control device 20 limits the vehicle drive torque for second motor generator 122 to the limit torque (step S110), and first motor generator 116. Is rotated to start the engine 112 (step S112). Further, control device 20 outputs the vehicle drive torque for second motor generator 122 or the limited vehicle drive torque to PCU 45 as a torque command (step S114). Thereafter, the processing after step S100 is repeated.

  When engine 112 is starting (in the case of “starting” in step S104), control device 20 limits the vehicle driving torque for second motor generator 122 to the limit torque (step S116), and the first motor. A reaction force canceling torque is determined based on the torque command for the generator 116 (step S118). Then, control device 20 adds the limited vehicle driving torque and reaction force canceling torque, and outputs the addition result to PCU 45 as a torque command (step S120). Thereafter, the processing after step S100 is repeated.

  When engine 112 has been started (in the case of “start completed” in step S104), control device 20 determines whether or not the margin torque is zero (step S122), and the margin torque must be zero. If (NO in step S122), a predetermined gradually decreasing amount is subtracted from the current margin torque to set a new margin torque (step S124). Then, when the margin torque is zero (YES in step S122) or set to a new margin torque (step S124), control device 20 sets the vehicle driving torque for second motor generator 122 to the new margin torque. The torque is limited to the limit torque corresponding to the torque (step S126). Further, control device 20 outputs the vehicle drive torque for second motor generator 122 or the vehicle drive torque after the limit to PCU 45 as a torque command (step S128). Thereafter, the processing after step S100 is repeated.

  As described above, the control device 20 implements engine start control corresponding to the block diagram shown in FIG.

  In the embodiment of the present invention, “starting means”, “reaction force canceling torque determining means”, “vehicle driving torque determining means”, “vehicle driving torque limiting means”, and “second motor generator control means” This is realized by the control device 20. Further, the engine starting unit 60 corresponds to “starting means”, the reaction force canceling torque determining unit 62 corresponds to “reaction force canceling torque determining means”, and the vehicle driving torque determining unit 64 is referred to as “vehicle driving torque determining means”. The vehicle drive torque limiting unit 66 corresponds to “vehicle drive torque limiting unit”, and the adder unit 68 corresponds to “second motor generator control unit”.

  According to the embodiment of the present invention, the vehicle driving torque limiting unit changes the margin according to the operating state of the engine, and the vehicle with respect to the second motor generator determined by the vehicle driving torque determination unit according to the margin. Limit the drive torque to the limit torque. Therefore, regardless of the vehicle driving torque generated by the second motor generator at the time of starting the engine, the second motor generator further generates a reaction force canceling torque for canceling the driving force fluctuation caused by the starting of the engine. be able to. Therefore, it is possible to realize a control device for a hybrid drive device that can suppress fluctuations in drive force that occur at the time of engine start or the like, which becomes a driving disturbance.

  Further, according to the embodiment of the present invention, the vehicle drive torque limiting unit gradually approaches the margin amount to zero in accordance with the engine starting process such as after completion of engine starting or during engine starting. That is, the vehicle drive torque limiting unit relaxes the limit torque because the necessary reaction force canceling torque decreases according to the engine starting process. Therefore, the driving torque that can be generated by the second motor generator increases, and the driving torque of the vehicle can be controlled within the range of the torque that can be generated by the second motor generator (rated torque). Therefore, the torque that can be generated by the second motor generator, which is necessary for applying the present invention, is the same as the conventional torque, and the present invention can be realized without changing the configuration of the hybrid drive device.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

1 is a schematic configuration diagram of a hybrid vehicle according to an embodiment of the present invention. It is a figure for demonstrating the conventional engine starting control which generates reaction force cancellation torque. It is a control block diagram for implement | achieving engine starting control in a control apparatus. It is a figure for demonstrating the engine starting control according to embodiment of this invention. FIG. 4 is a diagram showing a processing routine for realizing engine start control corresponding to the block diagram shown in FIG. 3.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Hybrid drive device, 20 Control apparatus, 30 Differential gear, 40 Power storage device, 45 PCU (Power Control Unit), 50 wheel, 60 Engine starting part, 62 Reaction force cancellation torque determination part, 64 Vehicle drive torque determination part, 66 Vehicle Drive torque limiter, 68 adder, 80 region, 112 engine, 114 damper device, 116 first motor generator, 118 output member, 120c carrier, 120s sun gear, 120r ring gear, 120 power split mechanism, 122 second motor generator, 122r Rotor, 124 motor shaft, 126 output gear, 128 intermediate shaft, 130 large gear, 132 small gear, 150 accelerator pedal, 152 shift lever.

Claims (6)

An engine that operates by combustion of fuel, a power split mechanism that mechanically distributes the output of the engine to the first motor generator and the output member, and a second motor generator that applies rotational force between the output member and the drive wheels A control device for a hybrid drive device comprising:
Start means for starting the engine by rotationally driving the engine via the power split mechanism by the first motor generator according to a running state;
Reaction force canceling torque determining means for determining a reaction force canceling torque for canceling fluctuations in driving force caused by starting of the engine by the starting means;
Vehicle driving torque determining means for determining a vehicle driving torque to be generated by the second motor generator according to a running state;
The limit torque obtained by subtracting a predetermined margin torque from the torque that can be generated by the second motor generator is not exceeded in a period during which the engine can be started by receiving the vehicle drive torque determined by the vehicle drive torque determination means. Vehicle driving torque limiting means for limiting the vehicle driving torque;
The second motor generator is controlled so that a torque obtained by adding the reaction force canceling torque determined by the reaction force canceling torque determining unit and the vehicle driving torque limited by the vehicle driving torque limiting unit is generated. A control device for a hybrid drive device, comprising: a second motor generator control means.   2. The control device for a hybrid drive device according to claim 1, wherein the margin torque corresponds to the maximum reaction force cancellation torque determined by the reaction force cancellation torque determination unit.   The control device for a hybrid drive apparatus according to claim 2, wherein the margin torque is set to a torque that can cancel a maximum value of a driving force fluctuation caused by starting of the engine.   The control device for a hybrid drive device according to any one of claims 1 to 3, wherein the vehicle drive torque limiting means gradually brings the margin torque closer to substantially zero according to a starting process of the engine.   The control device for a hybrid drive apparatus according to any one of claims 1 to 4, wherein the vehicle drive torque limiting means sets the margin torque to zero during operation of the engine.   6. The hybrid drive apparatus according to claim 1, wherein the starter starts the engine when the vehicle drive torque to be generated by the second motor generator exceeds the limit torque. 7. Control device.

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