JP5556580B2 - Control device for hybrid vehicle - Google Patents

Description

  The present invention has a hybrid vehicle travel mode (hereinafter referred to as “HEV travel mode”) and an engine use slip travel mode (hereinafter referred to as “WSC travel mode”) as travel modes, and mode transition from the WSC travel mode to the HEV travel mode is performed. The present invention relates to a control apparatus for a hybrid vehicle.

  Conventionally, there is known a control device for a hybrid vehicle having a WSC travel mode in which a friction element interposed between a motor and a drive wheel is slip-fastened in a state where the engine and the motor are fastened and the engine is driven while being included in a power source. (For example, refer to Patent Document 1).

JP 2010-143418 A

  However, in the conventional hybrid vehicle control device, the WSC travel mode is engaged with the friction element and the mode is changed to the HEV travel mode using the engine and the motor as drive sources in response to a sudden change in the required drive torque. The target drive torque sometimes changed suddenly. For this reason, the torque balance between the transmission torque capacity of the friction element and the target drive torque is lost, and the input rotational speed of the friction element increases, and there is a problem that a vehicle shock occurs when the engagement of the friction element is completed.

  The present invention has been made paying attention to the above-described problem, and controls a hybrid vehicle that can suppress the rising of the input rotational speed of the friction element at the time of mode transition from the engine-using slip traveling mode to the hybrid vehicle traveling mode. An object is to provide an apparatus.

In order to achieve the above object, the hybrid vehicle control apparatus of the present invention is configured to include an engine, a motor, a friction element, a mode switching means, and a target drive torque control means.
The motor is provided in a drive system from the engine to the drive wheels, and drives the drive wheels.
The friction element is interposed between the motor and the driving wheel, and connects and disconnects the motor and the driving wheel.
The mode switching means is a hybrid vehicle running mode in which the friction element is fastened and the vehicle is driven by the driving force of both the engine and the motor, and the drive in which the friction element is slip-fastened and transmitted through the friction element. Switches between slip mode and engine using slip mode.
The target drive torque control means performs torque limit control for limiting a change in the target drive torque with respect to a change in the required drive torque when performing a mode transition from the engine use slip running mode to the hybrid vehicle running mode.

Therefore, at the time of the mode transition from the engine use slip traveling mode to the hybrid vehicle traveling mode, the target drive torque control means limits the change in the target drive torque with respect to the change in the required drive torque.
That is, if the target drive torque is changed in accordance with the change in the required drive torque at the time of the mode transition, the target drive torque also changes suddenly when the required drive torque changes suddenly. Therefore, the target drive torque exceeds the transmission torque capacity of the friction element, the torque balance is lost, and the input rotation speed of the friction element increases. Therefore, by limiting the change in the target drive torque with respect to the change in the required drive torque, the target drive torque can be matched with the transmission torque capacity of the friction element, and the torque balance can be prevented from being lost.
As a result, at the time of mode transition from the engine using slip traveling mode to the hybrid vehicle traveling mode, it is possible to suppress the increase in the input rotational speed of the friction element.

1 is an overall system diagram showing an FR hybrid vehicle (an example of a hybrid vehicle) by rear wheel drive to which a control device of Embodiment 1 is applied. It is a figure which shows an example of the shift map of the automatic transmission set to the AT controller of Example 1. FIG. FIG. 3 is a control block diagram illustrating calculation processing performed by the integrated controller according to the first embodiment. It is a figure which shows an example of the EV-HEV selection map set to the mode selection part of the integrated controller of Example 1. It is a figure which shows an example of the driving | running | working electric power generation request output map set to the target electric power generation output calculating part of the integrated controller of Example 1. FIG. FIG. 3 is a control block diagram illustrating a target drive torque calculation unit according to the first embodiment. It is a figure showing the torque map set to the torque calculation part of the target drive torque calculation part of Example 1, (a) shows an example of the target drive force map by AT input rotation speed and accelerator opening APO, b) shows an example of a target driving force (creep driving force) map based on the brake depression force. It is a control block diagram which shows the 2nd filter process part of a target torque calculating part, (a) shows a 1st filter, (b) shows a 2nd filter. 3 is a flowchart illustrating a flow of target drive torque calculation processing executed by a target drive torque calculation unit according to the first embodiment. Driving mode switching flag, motor control mode, CL2 L / U determination flag, pre-processing target torque when torque limit control is performed at the time of WSC → HEV mode transition in an FR hybrid vehicle to which the control device of the first embodiment is applied 6 is a time chart showing characteristics of target drive torque, CL2 input rotation speed, CL2 output rotation speed, and target CL2 hydraulic pressure.

  Hereinafter, the best mode for realizing a control device for a hybrid vehicle of the present invention will be described based on a first embodiment shown in the drawings.

First, the configuration will be described.
FIG. 1 is an overall system diagram showing a rear-wheel drive FR hybrid vehicle (an example of a hybrid vehicle) to which the control device of the first embodiment is applied. The overall configuration will be described below with reference to FIG.

  As shown in FIG. 1, the drive system of the FR hybrid vehicle in the first embodiment includes an engine Eng, a flywheel FW, a first clutch CL1, a motor / generator (motor) MG, a transmission input shaft IN, Mechanical oil pump MO / P, sub oil pump SO / P, second clutch (friction element) CL2, automatic transmission AT, propeller shaft PS, differential DF, left drive shaft DSL, and right drive shaft It has a DSR, a left rear wheel (drive wheel) RL, and a right rear wheel (drive wheel) RR. Note that FL is the left front wheel and FR is the right front wheel.

  The engine Eng is a gasoline engine or a diesel engine, and engine start control, engine stop control, throttle valve opening control, fuel cut control, and the like are performed based on an engine control command from the engine controller 1. The engine output shaft is provided with a flywheel FW.

  The first clutch CL1 is a clutch interposed between the engine Eng and the motor / generator MG, and is generated by the first clutch hydraulic unit 6 based on the first clutch control command from the first clutch controller 5. Engagement / semi-engagement state / release is controlled by one clutch control oil pressure. As the first clutch CL1, for example, a normal state in which complete engagement is maintained by an urging force of a diaphragm spring, and from complete engagement to slip engagement to complete release is controlled by stroke control using a hydraulic actuator 14 having a piston 14a. A closed dry single plate clutch is used.

  The motor / generator MG is a synchronous motor / generator in which a permanent magnet is embedded in a rotor and a stator coil is wound around a stator, and a three-phase AC generated by an inverter 3 based on a control command from the motor controller 2. It is controlled by applying. This motor / generator MG can be driven to rotate by receiving power supplied from the battery 4, and can operate as an electric motor that starts the engine Eng and drives the left and right rear wheels RL and RR ("power running"). When the rotor receives rotational energy from the engine Eng and the left and right rear wheels RL and RR, it functions as a generator that generates electromotive force at both ends of the stator coil and can also charge the battery 4 ("regeneration").

  The mechanical oil pump M-O / P is provided on the transmission input shaft IN connected to the output shaft of the motor / generator MG, and is driven by the motor / generator MG. The mechanical oil pump M-O / P is used as a hydraulic pressure source for the hydraulic control valve unit CVU attached to the automatic transmission AT and the first clutch hydraulic unit 6 and the second clutch hydraulic unit 8 incorporated therein. The sub oil pump S-O / P is driven by the electric motor when the discharge pressure from the mechanical oil pump M-O / P cannot be expected or is insufficient.

  The second clutch CL2 is a friction element interposed between the motor / generator MG and the left and right rear wheels RL, RR, and is generated by the second clutch hydraulic unit 8 based on the second clutch control command from the AT controller 7. Fastening / slip fastening / release is controlled by the controlled hydraulic pressure. As the second clutch CL2, for example, a normally open wet multi-plate clutch or a wet multi-plate brake capable of continuously controlling the oil flow rate and hydraulic pressure with a proportional solenoid is used.

  The automatic transmission AT is a stepped transmission that automatically switches the stepped gears according to the vehicle speed, the accelerator opening, and the like. In the first embodiment, the automatic transmission AT has seven forward speeds and one reverse gear stage. It is a step transmission. In this automatic transmission AT, the driving force from at least one of the engine Eng and the motor / generator MG is input from the transmission input shaft IN, and the rotational speed is changed by the built-in gear mechanism and friction element, so that the transmission Output from the output shaft. In the first embodiment, the second clutch CL2 is not newly added as a dedicated clutch independent of the automatic transmission AT, but a plurality of friction elements that are engaged at each gear stage of the automatic transmission AT. Among them, a friction element (clutch or brake) that matches a predetermined condition is selected.

  One end of the propeller shaft PS is connected to the transmission output shaft of the automatic transmission AT, and the other end is connected to the left and right rear wheels RL, RR via the differential DF, the left drive shaft DSL, and the right drive shaft DSR. .

  The FR hybrid vehicle has an electric vehicle travel mode (hereinafter referred to as “EV travel mode”) and a hybrid vehicle travel mode (hereinafter referred to as “HEV travel mode”) as travel modes depending on driving modes. And engine use slip running mode (hereinafter referred to as “WSC running mode”).

  The “EV travel mode” is a mode in which the first clutch CL1 is disengaged and the second clutch CL2 is engaged, and the vehicle travels only with the driving force of the motor / generator MG, and has a motor travel mode and a regenerative travel mode. This “EV running mode” is selected when the required driving force is low and the battery SOC is secured.

  The “HEV travel mode” is a mode in which the first clutch CL1 and the second clutch CL2 are engaged and the vehicle travels with the driving force of both the engine Eng and the motor / generator MG. The motor assist travel mode, the power generation travel mode, and the engine It has a running mode. This “HEV travel mode” is selected when the required driving force is high or when the battery SOC is insufficient.

  The “WSC travel mode” is a mode in which the first clutch CL1 is engaged, the second clutch CL2 is slip-engaged, and the vehicle travels with the driving force transmitted through the second clutch CL2 while including the driving force of the engine Eng. It is. At this time, the transmission torque capacity of the second clutch CL2 is controlled by the rotation speed control of the motor / generator MG so as to have a value corresponding to the target drive torque. The “WSC travel mode” is selected in a travel region where the engine speed is lower than the idle speed, such as when the vehicle is stopped, started, or decelerated in the selected state of the “HEV mode”. Further, in the “WSC traveling mode”, creep traveling can be achieved even when the battery SOC is low or the engine water temperature is low.

Next, the control system of the FR hybrid vehicle in the first embodiment will be described.
As shown in FIG. 1, the control system of the FR hybrid vehicle in the first embodiment includes an engine controller 1, a motor controller 2, an inverter 3, a battery 4, a first clutch controller 5, and a first clutch hydraulic unit 6. And an AT controller 7, a second clutch hydraulic unit 8, a brake controller 9, and an integrated controller 10. The controllers 1, 2, 5, 7, and 9 and the integrated controller 10 are connected via a CAN communication line 11 that can exchange information with each other.

  The engine controller 1 inputs engine speed information from the engine speed sensor 12, a target engine torque command from the integrated controller 10, and other necessary information. Then, a command for controlling the engine operating point (Ne, Te) is output to the throttle valve actuator or the like of the engine Eng.

  The motor controller 2 inputs information from the resolver 13 that detects the rotor rotational position of the motor / generator MG, a target MG torque command and a target MG rotational speed command from the integrated controller 10, and other necessary information. Then, a command for controlling the motor operating point (Nm, Tm) of the motor / generator MG is output to the inverter 3. The motor controller 2 uses the motor torque as the target torque and the torque control that follows the rotation of the drive system as a basic control. However, during the slip control of the second clutch CL2, the motor rotation speed is set as the target rotation. The number of revolutions is controlled so that the torque follows the driving system load. Further, the motor controller 2 monitors the battery SOC indicating the charge capacity of the battery 4 and supplies the battery SOC information to the integrated controller 10 via the CAN communication line 11.

  The first clutch controller 5 inputs sensor information from the first clutch stroke sensor 15 that detects the stroke position of the piston 14a of the hydraulic actuator 14, a target CL1 torque command from the integrated controller 10, and other necessary information. . Then, a command for controlling engagement / semi-engagement / release of the first clutch CL1 is output to the first clutch hydraulic unit 6 in the hydraulic control valve unit CVU.

The AT controller 7 inputs information from an accelerator opening sensor 16, a vehicle speed sensor 17, a transmission input rotation speed sensor 18, and the like. When traveling with the D range selected, the optimum shift speed is searched based on the position where the driving point determined by the accelerator opening APO and the vehicle speed VSP exists on the shift map shown in FIG. The control command to obtain is output to the hydraulic control valve unit CVU. The shift map is a map in which an up shift line and a down shift line are written according to the accelerator opening APO and the vehicle speed VSP, as shown in FIG.
In addition to this shift control, when a target CL2 torque command is input from the integrated controller 10, a command for controlling the clutch hydraulic pressure to the second clutch CL2 is output to the second clutch hydraulic unit 8 in the hydraulic control valve unit CVU. 2-clutch control is performed.
Further, when a shift control command is output from the integrated controller 10 in engine start control or the like, the shift control according to the shift control command is performed in preference to the normal shift control.

  The brake controller 9 inputs a wheel speed sensor 19 for detecting the wheel speeds of the four wheels, sensor information from the brake pedal force sensor 20, a regenerative cooperative control command from the integrated controller 10, and other necessary information. And, for example, at the time of brake depression, if the regenerative braking force is insufficient with respect to the required braking force required from the brake stroke BS, the shortage is compensated with mechanical braking force (hydraulic braking force or motor braking force) Regenerative cooperative brake control is performed.

  The integrated controller 10 manages the energy consumption of the entire vehicle and has a function for running the vehicle with the highest efficiency. The integrated controller 10 detects the motor rotation speed Nm, and the lubricating oil for the automatic transmission AT. Necessary information from the ATF temperature sensor 22 for detecting the temperature of the ATF (hereinafter referred to as ATF), other sensors and switches 23, and information are input via the CAN communication line 11. The target engine torque command to the engine controller 1, the target MG torque command and the target MG speed command to the motor controller 2, the target CL1 torque command to the first clutch controller 5, the target CL2 torque command to the AT controller 7, and the brake controller 9 Regenerative cooperative control command is output.

  FIG. 3 is a control block diagram illustrating arithmetic processing performed by the integrated controller according to the first embodiment. 4 and 5 are diagrams illustrating examples of maps set in the mode selection unit and the target power generation output calculation unit of the integrated controller, respectively. Hereinafter, the arithmetic processing performed by the integrated controller will be described with reference to FIGS.

  As shown in FIG. 3, the integrated controller 10 includes a mode selection unit (mode switching means) 100, a target drive torque calculation unit 200, a target power generation output calculation unit 300, an operating point command unit 400, and a shift control unit. And 500.

The mode selection unit 100 selects a target travel mode (HEV travel mode, EV travel mode, WSC travel mode) from the accelerator opening APO and the vehicle speed VSP using the EV-HEV selection map shown in FIG.
In this EV-HEV selection map, when the operating point (APO, VSP) existing in the EV region crosses, the EV⇒HEV switching line that switches to “HEV driving mode” and the operating point (APO, VSP) existing in the HEV region ) Will switch to “EV drive mode” when the vehicle crosses HEV⇒EV switching line and the driving point (APO, VSP) existing in the HEV region will switch to “WSC driving mode”, and the operating point will exist in the WSC region When the (APO, VSP) crosses, a HEV⇔WSC switching line for switching to the “HEV traveling mode” is set.
The EV → HEV switching line and the HEV → EV switching line are set with a hysteresis amount as a line dividing the EV region and the HEV region. The HEV / WSC switching line is set along the first set vehicle speed VSP1 at which the engine Eng maintains the idling speed when the automatic transmission AT is in the first speed. However, if the battery SOC falls below a predetermined value while the “EV travel mode” is selected, the “HEV travel mode” is forcibly set as the target travel mode.

  The target drive torque calculation unit 200 executes a target drive torque calculation process, which will be described later, and calculates a target drive torque.

  The target power generation output calculation unit 300 calculates a target power generation output from the battery SOC using the traveling power generation request output map shown in FIG. Also, it calculates the output required to increase the engine torque from the current engine operating point (rotation speed, torque) to the best fuel consumption line, and adds it to the engine output as a required output compared to the target power generation output. To do.

  The operating point command unit 400 uses the accelerator opening APO, the target traveling mode, the target driving torque, the vehicle speed VSP, and the target power generation output as the operating point arrival target, and the transient target engine torque, target MG torque, and CL1. Solenoid current command, target CL2 torque capacity and target AT shift are calculated.

  The shift control unit 500 calculates an AT solenoid current command for driving and controlling a solenoid valve in the automatic transmission AT so as to achieve these from the target CL2 torque capacity and the target AT shift.

  FIG. 6 is a control block diagram illustrating a target drive torque calculation unit according to the first embodiment. FIG. 7 is a diagram illustrating an example of a map set in the torque calculation unit of the target drive torque calculation unit. FIG. 8 is a control block diagram showing the second filter processing unit of the target torque calculation unit, where (a) shows the first filter and (b) shows the second filter. FIG. 9 is a flowchart illustrating a flow of target drive torque calculation processing executed by the target drive torque calculation unit according to the first embodiment. Hereinafter, the calculation process performed by the target drive torque calculation unit will be described with reference to FIGS.

  As shown in FIG. 6, the target drive torque calculation unit 200 includes a torque calculation unit 201, a first filter processing unit 202, and a second filter processing unit (target drive torque control means) 203. .

  The torque calculation unit 201 uses the target driving force map based on the AT input speed and the accelerator opening APO shown in FIG. 7A and the target driving force map based on the brake pedal force shown in FIG. A target torque (target drive torque) is calculated. When the brake is released and the accelerator is depressed, the map shown in FIG. 7A is used. When the accelerator is released and the brake is depressed, the map shown in FIG. 7B is used. The pre-processing target torque calculated by the torque calculation unit 201 is a value corresponding to the required driving torque (driving performance request) determined according to the vehicle state and the driver's operation in consideration of the assist torque, that is, the required driving torque. The value is set to be

  The first filter processing unit 202 is selected at a time other than the mode transition from the WSC traveling mode to the HEV traveling mode. Then, normal filter processing necessary for suppressing vehicle shock is performed to obtain the target drive torque. That is, the first filter processing unit 202 does not limit the change in the pre-processing target torque with respect to the change in the required drive torque (operability request). A value obtained by changing the pre-processing target torque at a change rate equivalent to the change rate of the required drive torque is set as the target drive torque.

The second filter processing unit 203 is selected when the mode is changed from the WSC travel mode to the HEV travel mode and the motor / generator MG is under torque control or the motor operation disabling condition is satisfied. The second filter processing unit 203 obtains the target drive torque by performing a filter process (torque limit control) for limiting the change in the target torque before processing in response to the change in the required drive torque (runnability request). That is, in the second filter processing unit 203, even when the required drive torque (operability request) changes suddenly, a value obtained by limiting the change in the target torque before processing so as not to follow the sudden change is set as the target drive torque. To do. The torque control of the motor / generator MG is to control the output torque from the motor / generator MG so that the input torque to the second clutch CL2 becomes the target drive torque. The motor inoperable condition is a condition in which the motor / generator MG cannot operate, for example, when the battery SOC is less than a predetermined value.
The second filter processing unit 203 that performs the torque limiting process includes a first filter 203a that can be arbitrarily selected, and a second filter 203b. That is, the second filter processing unit 203 obtains the target drive torque using either the first filter 203a or the second filter 203b.

The first filter 203a is a filter that changes the target torque before processing according to a limited change rate (change rate limit value) to a target drive torque with respect to a change in the required drive torque.
In the first filter 203a, the change rate limit value is obtained using the change rate limit value map based on the slip rotation speed (CL2 slip rotation speed) of the second clutch CL2 and the pre-processing target torque shown in FIG. . Here, the larger the change rate limit value, the more the change rate is restricted. Even if the change rate of the required drive torque is large, the change rate of the pre-processing target torque is small.

The second filter 203b is a filter that sets a limit torque value and sets the change in the target torque before processing to the target drive torque without following the change in the required drive torque when the required drive torque exceeds the limit torque value. is there.
In the second filter 203b, as shown in FIG. 8B, the hydraulic response of the second clutch CL2 is predicted from the ATF temperature. Then, in consideration of the CL2 oil pressure response, the driving torque is obtained by converting the target CL2 oil pressure. Then, the safety factor K (0 <K <1) is integrated with the obtained drive torque to obtain the limit torque value.

  With reference to the flowchart shown in FIG. 9, the flow of the target drive torque calculation process executed by the target drive torque calculation unit of the first embodiment will be described. This target drive torque calculation process is executed in the WSC travel mode.

  In step S1, a pre-processing target torque that matches the required driving torque determined according to the vehicle state and the driver's operation is calculated, and the process proceeds to step S2.

  In step S2, following the calculation of the target torque before processing in step S1, it is determined whether or not the operating point (APO, VSP) existing in the WSC region crosses the WSC⇔HEV switching line in the EV-HEV selection map. If YES (crossed), the process proceeds to step S3. If NO (not crossed), the process proceeds to step S5.

  In step S3, following the determination that the WSC⇔HEV switching line has been crossed in step S2, it is determined whether or not the lockup determination of the second clutch CL2 has been made, that is, whether or not the L / U flag has been output, If YES (lockup complete), the process proceeds to step S6. If NO (lockup incomplete), the process proceeds to step S4. It should be noted that the lock-up determination of the second clutch CL2 is performed for a predetermined time after a command that the input / output differential rotation in the second clutch CL2 is within a predetermined value and the target CL2 hydraulic pressure sufficiently overcomes the target torque before processing is issued. When the time has elapsed, it is determined that the lockup is completed.

  In step S4, following the determination that the lockup is not completed in step S3, it is determined that the mode transition is in progress from the WSC travel mode to the HEV vehicle travel mode, and the process proceeds to step S7.

  In step S5, following the determination that the WSC⇔HEV switching line is not crossed in step S2, it is determined that the WSC travel mode is set, and the process proceeds to step S9.

  In step S6, following the determination of the completion of lockup in step S3, it is determined that the HEV traveling mode is set as the transition to the HEV traveling mode is completed, and the process proceeds to step S9.

  In step S7, following the determination that the mode transition is being performed in step S4, it is determined whether torque control of the motor / generator MG is being performed or whether the motor operation disabling condition is satisfied, and YES ( If it is during torque control or motor operation is not possible, the process proceeds to step S8, and if NO (during rotation control and motor operation is possible), the process proceeds to step S9. The torque control of the motor / generator MG is to control the output torque from the motor / generator MG so that the input torque to the second clutch CL2 becomes the target drive torque. The motor inoperable condition is a condition in which the motor / generator MG cannot operate, for example, when the battery SOC is less than a predetermined value.

  In step S8, following the determination that the motor torque is being controlled or incapable of motor operation in step S7, torque limit control in which the target drive torque is a value obtained by limiting the change in the target torque before processing with respect to the change in the required drive torque. And go to the end.

  In step S9, following the determination of the WSC driving mode in step S5, the determination of the HEV driving mode in step S6, and the determination of whether the motor can be operated during motor rotation control in step S7, the requested drive Normal control is performed in which the target drive torque is a value obtained by changing the pre-processing target torque in response to the change in torque, and the process proceeds to the end.

Next, the operation will be described.
The “target torque limit control action” in the control apparatus for the FR hybrid vehicle of the first embodiment will be described.

[Target torque limit control action]
FIG. 10 illustrates a travel mode switching flag, a motor control mode, a CL2 L / U determination flag, and a process when torque limit control is performed at the time of WSC → HEV mode transition in the FR hybrid vehicle to which the control device of the first embodiment is applied. 6 is a time chart showing characteristics of a previous target torque, a target drive torque, a CL2 input rotation speed, a CL2 output rotation speed, and a target CL2 hydraulic pressure.

  In the WSC travel mode, the first clutch CL1 is engaged, slip control is performed so that the second clutch CL2 has a transmission torque capacity corresponding to the target drive torque, and travel is performed while including the driving force of the engine Eng as a power source. Note that the slip control of the second clutch CL2 in the WSC travel mode is realized by the rotational speed control of the motor / generator MG.

  In such a WSC travel mode, the process proceeds from step S1 to step S2 to step S5 to step S9 in the flowchart shown in FIG. For this reason, the target drive torque in the WSC travel mode is a value obtained by performing a normal filter process necessary for suppressing vehicle shock with respect to the target torque before processing set according to the required drive torque. .

  When the input / output differential speed in the second clutch CL2 gradually decreases and the operating point (APO, VSP) existing in the WSC area of the EV-HEV selection map crosses the HEV⇔WSC switching line at time t1, the driving mode The switching flag is changed from “WSC mode” to “mode transition”. Thus, the motor / generator MG is changed from the rotation speed control mode to the torque control mode, and the output torque from the motor / generator MG is controlled so that the input torque to the second clutch CL2 becomes the target drive torque. . On the other hand, the target value of the engagement hydraulic pressure of the second clutch CL2 (hereinafter referred to as the target CL2 hydraulic pressure) gradually increases from time t1, and the transmission torque capacity of the second clutch CL2 is gradually increased.

  Then, it is assumed that the required drive torque rapidly increases due to a strong depression of the accelerator at time t2 when a predetermined time has elapsed from time t1.

  At this time, in the flowchart shown in FIG. 9, the process proceeds from step S 1 → step S 2 → step S 3 → step S 4 → step S 7 → step S 8, and torque limit for limiting the change in the target drive torque with respect to the change in the required drive torque. Control is executed.

  That is, since the target torque before processing is a value set according to the required drive torque, it changes suddenly in response to a change in the required drive torque. On the other hand, the target drive torque becomes a value in which the change in the target torque before processing is limited by the change rate limit value obtained by the first filter 203a shown in FIG. 8A, for example. As a result, the inclination of the target drive torque becomes gentler than the inclination of the target torque before processing. For this reason, the change in the target drive torque becomes gradual, and the target drive torque does not exceed the transmission torque capacity of the second clutch CL2. Then, the balance of torque between the transmission torque capacity and the target drive torque is prevented from being lost, and the input rotational speed of the second clutch CL2 can be suppressed from rising.

  Further, since this torque limit control is executed when the torque control of the motor / generator MG is being performed, it is possible to easily perform the control with high accuracy. That is, the torque transmitted by the second clutch CL2 can be matched with the target drive torque limited by the motor / generator MG having better control response than the engine Eng, and control can be performed with high accuracy.

  When the input / output differential rotation speed becomes equal to or less than the predetermined value at time t3, the pre-processing target torque becomes a constant value in accordance with the required drive torque. On the other hand, the target drive torque obtained by the second filter processing unit 203 increases with a constant slope after time t3.

  Then, at time t4 when a predetermined time has elapsed after the input / output differential rotation speed of CL2 falls within the predetermined value, the transmission torque capacity of CL2 is large enough to overcome the target torque before processing (= required drive torque). So as to increase the target CL2 hydraulic pressure. At this time, since the input / output differential rotation speed is equal to or less than the predetermined value, the engagement shock of the second clutch CL2 does not occur.

  Further, the target CL2 hydraulic pressure is set so as to increase with a slope corresponding to the input / output differential rotational speed and the target drive torque from time t1 to time t4 when the input / output differential rotational speed is generated in the second clutch CL2. ing. That is, the target CL2 hydraulic pressure increases according to the change in the target drive torque, and the input / output differential rotation speed is controlled so as not to exceed the allowable heat generation amount of the second clutch CL2.

  As a result, the input / output rotational difference can be smoothly converged while the second clutch CL2 is thermally protected, and the occurrence of a vehicle shock can be suppressed. That is, the target CL2 hydraulic pressure is increased with a slope corresponding to the target drive torque controlled so that the change is limited with respect to the change in the required drive torque. For this reason, the target drive torque can be matched with the transmission torque capacity of the second clutch CL2, and the balance of torque between the target drive torque and the transmission torque capacity can be prevented, and the transmission torque capacity of the second clutch CL2 is smooth. Can be increased. As a result, the increase in the input rotational speed of the second clutch CL2 is suppressed, the second clutch CL2 can be smoothly engaged, and a vehicle shock can be prevented from occurring when the engagement is completed.

  Furthermore, a predetermined time from time t4 when the input / output differential rotation speed of the second clutch CL2 is less than or equal to a predetermined value and the target CL2 hydraulic pressure is sufficiently large to overcome the pre-processing target torque (= required drive torque). At the time t5 when elapses, the lockup completion determination of the second clutch CL2 is made. As a result, the lockup (L / U) determination flag of the second clutch CL2 is completed, and the transition to the HEV travel mode is completed, and the travel mode switching flag is changed from “mode transition” to “HEV mode”. .

  At this time, in the flowchart shown in FIG. 9, the process proceeds from step S1, step S2, step S3, step S6, and step S9. As a result, the target drive torque is a value obtained by performing a normal filter process necessary for suppressing vehicle shocks with respect to the pre-process target torque set according to the required drive torque. Note that the inclination of the target drive torque at this time is larger than the inclination of the target torque before processing from time t2 to time t3, and the rate of change is large. However, the input / output differential rotation speed of the second clutch CL2 is within a predetermined value at the time t3, and the engagement of the second clutch CL2 is completed at the time t5. For this reason, even if the target drive torque changes greatly, the occurrence of a vehicle shock due to the differential rotation of the second clutch CL2 does not occur, and smooth running can be performed.

Next, the effect will be described.
In the hybrid vehicle control device of the first embodiment, the following effects can be obtained.

(1) An engine Eng, a motor (motor / generator) MG provided in a drive system from the engine Eng to drive wheels (left and right rear wheels) RL, RR for driving the drive wheels RL, RR, and the motor A friction element (second clutch) CL2 that is interposed between MG and the driving wheels RL and RR and connects and disconnects the motor MG and the driving wheels RL and RR, and the friction element CL2 are fastened, and the engine Eng And hybrid vehicle travel mode (HEV travel mode) that travels with the driving force of both the motor MG and slip using the engine that slip-fastens the friction element CL2 and travels with the driving force transmitted through the friction element CL2. A mode switching means (mode selection unit) 100 for switching between a traveling mode (WSC traveling mode) and a change in required driving torque when performing a mode transition from the engine use slip traveling mode to the hybrid vehicle traveling mode. The target drive torque control means (second filter processing unit) 203 that performs torque limit control for limiting a change of the target drive torque (pretreatment target torque), and configured to include a.
For this reason, at the time of the mode transition from the engine use slip traveling mode to the hybrid vehicle traveling mode, it is possible to suppress the increase in the input rotational speed of the friction element.

(2) The target drive torque control means (second filter processing unit) 203 is configured to perform torque control of the motor MG and perform torque limit control.
For this reason, in addition to the effect (1), torque limit control is realized by torque control of the motor MG, and accurate control can be easily performed.

(3) The target drive torque control means (second filter processing unit) 203 controls the friction element CL2 so that the heat generation amount of the friction element CL2 does not exceed the allowable heat generation amount during execution of the torque limit control. It was set as the structure which controls differential rotation.
For this reason, in addition to the effect of (1) or (2), the input / output rotational difference can be smoothly converged while the thermal protection of the friction element CL2 is performed, and the occurrence of vehicle shock can be suppressed.

  Although the hybrid vehicle control device of the present invention has been described based on the first embodiment, the specific configuration is not limited to this embodiment, and the invention according to each claim of the claims is not limited thereto. Design changes and additions are allowed without departing from the gist.

  In the first embodiment, an example is shown in which the change in the target torque before processing is limited by the change rate limit value obtained by the first filter 203a shown in FIG. However, it is also possible to limit the change in the target torque before processing based on the limit torque value obtained by the second filter 203b shown in FIG. Further, the second filter processing unit 203 may have only one of the first filter 203a and the second filter 203b.

  In the first embodiment, an example is shown in which the second clutch CL2 is selected from the friction elements incorporated in the stepped automatic transmission AT. However, the second clutch CL2 may be provided separately from the automatic transmission AT. For example, the second clutch CL2 may be provided separately from the automatic transmission AT between the motor / generator MG and the transmission input shaft. An example in which the second clutch CL2 is provided separately from the automatic transmission AT between the transmission output shaft and the drive wheels is also included.

  In the first embodiment, an example is shown in which a stepped automatic transmission with 7 forward speeds and 1 reverse speed is used as the automatic transmission AT. However, the number of gears is not limited to this, and a continuously variable transmission can be used as long as the second clutch CL2 is provided separately from the automatic transmission AT.

  In the first embodiment, an example in which the first clutch CL1 is used as a mechanism for connecting and disconnecting power transmission between the engine Eng and the motor / generator MG has been described. However, the present invention is not limited to this. For example, a differential gear or a power split device that exhibits a clutch function without using a clutch, such as a planetary gear, may be used.

  In the first embodiment, the control device is applied to a rear-wheel drive hybrid vehicle. However, the control device can also be applied to a front-wheel drive hybrid vehicle. In short, any hybrid vehicle having the HEV travel mode and the WSC travel mode as the travel mode can be applied.

Eng engine
CL1 1st clutch
MG motor / generator (motor)
CL2 2nd clutch (friction element)
AT automatic transmission
RL Left rear wheel (drive wheel)
RR Right rear wheel (drive wheel)
10 Integrated controller
100 Mode selection section (mode switching means)
200 Target drive torque calculator
203 Second filter processing unit (target drive torque control means)
203a first filter
203b Second filter

Claims (2)

Engine,
A motor that is provided in a drive system from the engine to drive wheels and that drives the drive wheels;
A friction element interposed between the motor and the drive wheel, and connecting and disconnecting the motor and the drive wheel;
A hybrid vehicle travel mode in which the friction element is fastened and travels with the driving force of both the engine and the motor, and an engine that is slip-fastened with the friction element and travels with the driving force transmitted through the friction element Mode switching means for switching between slip running modes;
When the mode transition from the engine-use slip running mode to the hybrid vehicle running mode is performed, the torque control of the motor is performed, and the torque limit control is performed to limit the change of the target drive torque with respect to the change of the required drive torque. Target drive torque control means;
A control apparatus for a hybrid vehicle, comprising: In the hybrid vehicle control device according to claim 1,
The target drive torque control means controls the differential rotation in the friction element so that the heat generation amount of the friction element does not exceed an allowable heat generation amount during execution of the torque limit control . Control device.