JP2008189102A - Control apparatus for hybrid vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control apparatus for a hybrid vehicle that improves an insufficient driving force by shortening an engine start time. <P>SOLUTION: In the control apparatus for a hybrid vehicle that comprises an engine, a motor generator, a battery for supplying power to the motor generator and storing regenerated power from the motor generator, a first clutch for connecting the engine to the motor generator, a second clutch for connecting the motor generator to a transmission, and a control means for controlling the engine, motor generator and first and second clutches, and that controls the first clutch and second clutch to drive the vehicle by either or both of the engine and the motor generator, the control means is configured to ignite the engine for starting the engine when the engine reaches an ignitable rotational angle. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a control device for a hybrid vehicle that obtains driving force from an engine and a motor generator.

  Conventionally, in a hybrid vehicle, an engine and a motor generator are arranged in series, the engine and the motor generator are connected via a first clutch, and the output shaft of the motor generator and the transmission are connected via a second clutch. There is something.

In this hybrid vehicle, when the required driving force is small, such as when starting, the EV mode in which the first clutch is released and only the motor generator is driven is selected, and when the required driving force is large, such as during high speed driving, the first clutch is The HEV mode is selected to obtain the driving force from the engine in addition to the motor generator (see, for example, Patent Document 1).
JP 2000-255285 A

  In the engine-motor generator serial connection type hybrid vehicle as described above, the EV mode is selected when the vehicle is stopped, and the EV mode is changed to the HEV mode when the accelerator is greatly depressed when starting.

At that time, the first clutch is engaged and the engagement force of the second clutch is reduced to transmit the rotation of the motor generator to the engine, and the engine is started. Therefore, the torque generated by the motor generator is divided into torque that rotates the engine via the first clutch and torque that is transmitted to the transmission via the second clutch. The input torque becomes smaller. Therefore, when the engine start time is prolonged and the engine start timing is delayed, there is a problem that the driving force is insufficient during the delay.
In general, when starting an engine by a motor generator in a hybrid vehicle, fuel is injected and the engine is ignited after the engine speed has increased to an engine speed that enables stable torque control by cranking.

  On the other hand, when the torque for rotating the engine is reduced and directed to the transmission to make up for insufficient driving force, the starting torque increases but the engine start time becomes longer. Conversely, if the torque input to the transmission is directed to the engine start in order to advance the engine start time, the driving force decreases.

  The present invention has been made paying attention to the above problems, and an object of the present invention is to provide a control device for a hybrid vehicle in which engine start time is shortened and deficiency in driving force is improved.

  In order to achieve the above object, in the present invention, an engine, a motor generator, a battery that supplies electric power to the motor generator and stores regenerative electric power of the motor generator, and the engine and the motor generator are connected. A first clutch; a second clutch that connects the motor generator and the transmission; and a control unit that controls the engine, the motor generator, and the first and second clutches, the first clutch and the By controlling the second clutch, in the control device for a hybrid vehicle that travels by one or both of the engine and the motor generator, the control means sets the rotation angle at which the engine can be ignited when starting the engine. The engine was ignited when reached.

  Therefore, it is possible to provide a control device for a hybrid vehicle in which the engine start time is shortened and the shortage of driving force is improved by igniting the engine without waiting for the engine speed to increase to a speed at which torque control is possible.

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

[System configuration]
FIG. 1 is a system diagram of the hybrid vehicle of the present application. The hybrid vehicle of the present application includes an engine E, a motor generator MG, first and second clutches CL1 and CL2, an automatic transmission AT, a left rear wheel RL (drive wheel), and a right rear wheel RR (drive wheel). Note that FL is the left front wheel and FR is the right front wheel.

  The engine E is a gasoline engine or a diesel engine, and based on a control command from the engine controller 1, the valve opening of the throttle valve and the like are controlled.

  The first clutch CL <b> 1 is interposed between the engine E and the motor generator MG, and is engaged / released by the first clutch hydraulic unit 6 based on a control command from the first clutch controller 5.

  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 rotor that is an output shaft is connected to an input shaft of automatic transmission AT. In driving, it is controlled by the inverter 3 a of the power control unit 3 based on a control command from the motor controller 2.

  The motor generator MG functions as an electric motor that is driven to rotate by receiving power supplied from the battery 4 (power storage device). Further, when rotating by an external force, it functions as a generator and can charge the battery 4.

  The power control unit 3 includes an inverter 3a, a high voltage circuit 3b, and a DC / DC converter 3c. Inverter 3 a is a semiconductor switching element, and converts the direct current of battery 4 into a three-phase alternating current and outputs it to motor generator MG, and converts the three-phase alternating current from motor generator MG into a direct current and outputs it to battery 4.

  The high-power circuit 3b is disposed between the battery 4, the inverter 3a, and the DC / DC converter 3c, and interrupts the flow of power by a relay provided therein. The DC / DC converter 3c steps down the voltage of the battery 4 and supplies power to the auxiliary battery 25 (power source for lighting, display, auxiliary equipment, etc.).

  The second clutch CL2 is a starting clutch of the automatic transmission AT, and is interposed between the motor generator MG and the automatic transmission AT. Engagement / release control is performed by the second clutch hydraulic unit 8 based on a control command from the AT controller 7.

  The automatic transmission AT is a stepped transmission that automatically changes the gear position according to the vehicle speed, accelerator opening, etc., and the input side is connected to the rotor of the motor generator MG via the second clutch CL2, and the output side Are connected to the left and right rear wheels RL, RR.

[Driving mode]
The hybrid vehicle of the present application has two driving modes of EV mode (running only with the driving force of the motor generator MG) and HEV mode (using driving force of the motor generator MG and the engine E) according to the engaged / released state of the first clutch CL1. Have

(EV mode)
When the first clutch CL1 is in the disengaged state, the driving force of the engine E is not transmitted to the automatic transmission AT, and the vehicle is in the EV mode in which only the power of the motor generator MG runs.

(HEV mode)
When the first clutch CL1 is in the engaged state, the driving force of the engine E is transmitted to the automatic transmission AT via the motor generator MG and the second clutch CL2, and the driving force of the engine E is used in addition to the motor generator MG. The HEV mode is set.

  In the HEV mode, the mode is further subdivided according to the magnitude and sign of driving force T (MG) generated by motor generator MG.

(Engine running mode)
If the driving force T (MG) is zero, the engine traveling mode is established in which traveling is performed only by the driving force of the engine E.

(Motor assisted travel mode)
If the driving force T (MG) input from the motor generator MG to the automatic transmission AT is a positive value, the motor assist traveling mode is set in which the driving force of the motor generator MG and the engine E is used in combination.

(Running power generation mode)
The driving force T (MG) input from the motor generator MG to the automatic transmission AT is a negative value, that is, the motor generator MG does not generate torque but is rotated by the engine E or vehicle inertia and consumes external torque. In this case, the motor generator MG functions as a generator. Thereby, the battery 4 is charged.
If the vehicle is in an acceleration state or a constant speed traveling state, motor generator MG is rotated by engine E, and if the vehicle is in a deceleration state, motor generator MG is rotated by vehicle inertia to generate power.

[Control configuration]
The hybrid vehicle of the present application includes an engine controller 1, a motor controller 2, a power control unit 3, a battery 4, an AT controller 7, and an integrated controller 10, which are connected via CAN communication lines 11 that can exchange information.

  The engine speed information from the engine speed sensor 12 is input to the engine controller 1, and the engine operating point (Ne: engine speed, Te: engine torque) is controlled according to the target engine torque command from the integrated controller 10. To do. The engine speed Ne is output to the integrated controller 10 via the CAN communication line 11.

  The motor controller 2 is based on the rotor rotational position of the motor generator MG (detected by the resolver 13), the target motor generator torque command (calculated in the integrated controller 10), and the like, and the motor operating point of the motor generator MG (motor generator rotational speed N, motor A command for controlling the generator torque Tm) is output to the power control unit 3.

  Further, the motor controller 2 monitors the battery SOC indicating the state of charge of the battery 4. The battery SOC is used for control information of the motor generator MG and is supplied to the integrated controller 10 via the CAN communication line 11.

  The AT controller 7 is based on sensor information from the accelerator opening sensor 16, the vehicle speed sensor 17 and the second clutch hydraulic pressure sensor 18, and the second clutch control command from the integrated controller 10, and the engagement / release control command for the second clutch CL2. Is output to the second clutch hydraulic unit 8. Information on the accelerator opening APO and the vehicle speed VSP is supplied to the integrated controller 10 via the CAN communication line 11.

  The integrated controller 10 manages the energy consumption of the entire vehicle and bears a function for running the vehicle with the highest efficiency. Motor speed Nm, second clutch output speed N2out, and second clutch torque TCL2 are input from motor speed sensor 21, second clutch output speed sensor 22, and second clutch torque sensor 23, respectively, and a CAN communication line. The information obtained through 11 is input.

  Based on the input information, the integrated controller 10 outputs commands to the engine controller 1, the motor controller 2, the first clutch controller 5, and the AT controller 7, and the engine E, the motor generator MG, and the first and second clutch CL1, respectively. , CL2 are controlled.

[Start-up time reduction control]
(Main flow)
FIG. 2 is a main flow of engine start time reduction control during hybrid travel. Hereinafter, each step will be described.

  In step S1, the target driving force of the vehicle is calculated based on the accelerator opening, etc., and the process proceeds to step S2.

  In step S2, the target shift speed is calculated, and the process proceeds to step S3.

  In step S3, a target mode (each mode of EV traveling, HEV traveling, and engine traveling) is calculated, and the process proceeds to step S4.

  In step S4, engine command calculation (start / stop request according to each mode, target rotational speed, target torque, etc.) is performed, and the process proceeds to step S5.

  In step S5, the mode transition states of EV traveling, HEV traveling, and engine traveling are calculated, and the process proceeds to step S6.

  In step S6, the target driving force transient correction of the vehicle is performed, and the process proceeds to step S7.

  In step S7, the target transmission torque of the first clutch CL1 is calculated, and the process proceeds to step S8.

  In step S8, a command value (target rotational speed, target torque, etc.) of motor generator MG is calculated, and the process proceeds to step S9.

  In step S9, the target transmission torque of the second clutch CL2 is calculated, and the control ends.

(Engine command calculation in start time reduction control)
FIG. 3 is a main flow of engine command calculation (FIG. 2: step S4) in engine start time reduction control.

  In step S11, it is determined whether or not the target mode is the engine running mode. If YES, the process proceeds to step S12, and if NO, the process proceeds to step S13.

  In step S12, it is determined whether or not the actual control mode is the engine running mode. If YES, the process proceeds to step S14, and if NO, the process proceeds to step S15.

  In step S13, it is determined whether or not the actual control mode is the engine running mode. If YES, the process proceeds to step S16, and if NO, the process proceeds to step S17.

  In step S14, an engine command calculation during engine running is executed, and the control is terminated.

  In step S15, the engine command calculation during the transition from the EV mode to the HEV mode is executed, and the control is terminated.

  In step S16, an engine command calculation for shifting from the HEV mode to the EV mode is executed, and the control is terminated.

  In step S17, an engine command calculation during EV mode traveling is executed, and the control is terminated.

[Start-up time shortening control (engine command calculation when shifting to EV-HEV mode)]
FIG. 4 is an engine command calculation flow at the time of transition from EV to HEV mode (FIG. 3: step S15). If the engine start timing is delayed, the starting torque during that time will be insufficient. Therefore, in this flow (steps S106 to S113), control for shortening the engine start time is executed, and the engine E is ignited immediately when the engine reaches a rotation angle that can be ignited. To do. As a result, the engine starting time is shortened to improve the start torque shortage.

  In step S101, the fuel cut flag is set to 0, and the process proceeds to step S102.

  In step S102, it is determined whether or not differential rotation of second clutch CL2 ≦ slip determination differential rotation (slip determination threshold). If YES, the process proceeds to step S103, and if NO, the process proceeds to step S106.

  In step S103, the engine start request flag is set to 0, and the process proceeds to step S104.

  In step S104, the engine torque command value is set to 0, and the control is terminated.

  In step S105, the engine idle request = 0 is set and the control is terminated.

In step S106, it is determined whether or not the engine speed is equal to or greater than the engine start speed (one rotation in the present application). If YES, the engine start is completed and the process proceeds to step S107. If NO, the process proceeds to step S103.
In a four-cycle engine, if the engine rotates once or more, all four strokes of intake, compression, expansion, and exhaust are performed, so that the ignition possible rotation angle is reached at the second rotation. Therefore, in this application, it is determined that 1 rotation is equal to the engine ignition possible rotation speed, and that the ignition is possible if the engine rotation speed is 1 rotation or more.

In step S107, it is determined whether or not engine rotational speed ≧ engine all cylinder ignition completion rotational speed (two revolutions in the present application). If YES, the process proceeds to step S111, and if NO, the process proceeds to step S108.
As described above, in the 4-cycle engine, the ignition possible rotation angle is reached at the second rotation, so in this application, 2 rotations = engine all-cylinder ignition completion rotation speed, and if the engine rotation speed is 2 rotations or more, it is determined that ignition is completed.

  The flow of steps S108 → S109 → S110 and steps S111 → S112 → S113 is the same as steps S103 → S104 → S105.

  Thus, by appropriately determining the engine start and ignition timing, unnecessary idle time is reduced, the engine start time is shortened, and the time during which motor generator MG bears friction for engine start is reduced. Even when a large engine torque is generated after the start, there is no problem because it can be absorbed by the slip of the second clutch CL2 and an excessive torque can be prevented from being transmitted to the drive wheels RL and RR.

  Conventionally, since engine torque control is performed at the time of engine start, the engine is ignited for the first time when the engine speed is controlled so that the engine start time tends to be prolonged. In the present application, since ignition is performed immediately at the number of revolutions that can be ignited (second rotation), the engine start time can be shortened compared to the conventional example.

  In addition, the throttle opening is reduced to an opening suitable for starting the engine until the ignition completion is determined. After the ignition is determined, the throttle opening can be quickly increased by increasing the throttle opening to an opening capable of torque control of the engine E. To generate engine torque.

  Due to the generation of the engine torque, the rotation of the engine E is increased by its own torque, and the motor generator torque consumed for increasing the engine rotation is reduced. Therefore, the proportion of the torque generated by motor generator MG that is distributed to the driving force increases, and the torque at the time of engine start is ensured.

[Starting time reduction control (first clutch target transmission torque calculation)]
FIG. 5 is a flow of target transmission torque calculation (FIG. 2: step S7) of the first clutch CL1. In order to make the engine start timing earlier, when the differential rotation of the first clutch CL1 is detected, the fastening force of the first clutch CL1 is increased, and a large torque is transmitted to the engine E so that the engine E can be started easily. (Steps S204 → S205 → S207 → S211).

  Further, since the rotation of the engine E rises autonomously after starting, it is not necessary to increase the rotation speed of the engine E by the torque of the first clutch CL1. Therefore, when the engine speed is detected after the engine E is started, the transmission torque of the first clutch CL1 is maintained as in the previous control (steps S205 → S206), and the increase in the engagement force of the first clutch CL1 is stopped to stop the motor generator. The surplus torque of MG is directed to the driving force via the second clutch CL2.

  In step S201, it is determined whether or not the normal control is being performed (the engine torque is being transmitted with a constant fastening force). If YES, the process proceeds to step S202, and if NO, the process proceeds to step S210.

  In step S202, it is determined whether or not there is an engine start request. If YES, the process proceeds to step S203, and if NO, the process proceeds to step S209.

  In step S203, the control mode of the first clutch CL1 is set to the capacity control mode (mode in which transmission torque is not 0), and the process proceeds to step S204.

  In step S204, it is determined whether or not there is a differential rotation of the first clutch CL1, and if there is a differential rotation, the process proceeds to step S205, and if not, the process proceeds to step S208.

  In step S205, the presence / absence of engine rotation is determined. If there is rotation, the process proceeds to step S206, and if not, the process proceeds to step S207. Since the 4-cycle engine can be started from the second rotation as described above, the engine E is determined to start when the engine speed is detected.

  In step S206, the first clutch torque correction value is maintained as in the previous control, and the process proceeds to step S211.

  In step S207, the first clutch torque correction value is set to the correction value of the previous control + the correction amount, and the process proceeds to step S211.

  In step S208, the first clutch transmission torque = 0, and the process proceeds to step S212.

  In step S209, the control mode of the first clutch CL1 is set to the standby mode (transfer torque = 0), and the process proceeds to step S213.

  In step S210, the control mode of the first clutch CL1 is set to the release mode (transfer torque = 0), and the process proceeds to step S213.

  In step S211, the engine starting torque + the first clutch torque correction value is set as the first clutch target transmission torque, and the control is terminated.

  In step S212, the first clutch target transmission torque is set to the maximum transmittable torque, and the control is terminated.

  In step S213 and step S214, the first clutch target transmission torque = 0 is set and the control is terminated.

[Start-up time reduction control (motor generator target speed calculation)]
FIG. 6 is a flowchart for calculating the target rotational speed of motor generator MG (FIG. 2: step S8). In FIG. 6, motor generator MG is simply referred to as a motor.

  If the engine speed increases and reaches a speed at which engine torque control is possible, the motor generator MG does not need to increase the engine E speed (the engine speed of the engine E is higher than that). To be gained by climbing).

  Therefore, the target rotational speed of motor generator MG may be lower than the engine-controllable rotational speed. Therefore, after the engine is ignited, when the target rotational speed of the motor generator MG exceeds the engine controllable rotational speed (described as the engine lower limit rotational speed in FIG. 6), the target rotational speed of the motor generator MG = the engine torque control is possible. The rotation number is set (steps S306 → S307 → S308).

  Thereby, an unnecessary increase in the rotational speed of motor generator MG at the time of engine start is suppressed. Since it is not necessary to transmit the torque of the motor generator MG to the engine E after the engine is started, the surplus torque of the motor generator MG is directed to the driving force via the second clutch CL2.

  In step S301, it is determined whether or not the current control mode is the engine running mode. If YES, the process proceeds to step S302, and if NO, the process proceeds to step S305.

  In step S302, it is determined whether or not the input shaft rotation speed of the transmission AT> the engine lower limit rotation speed. If YES, the process proceeds to step S304, and if NO, the process proceeds to step S303.

  In step S303, the target engine speed is read from the map, and the process proceeds to step S309.

  In step S304, the target motor speed is set to the transmission input shaft speed, and the process proceeds to step S309. Since the input shaft rotational speed of the automatic transmission AT exceeds the engine lower limit rotational speed, if the rotational speed of the motor generator MG = the automatic transmission AT input shaft rotational speed, the rotational speed sufficient for starting the engine is maintained. The rotation of the automatic transmission AT can also be maintained.

  In step S305, target motor rotation speed = transmission input shaft rotation speed + second clutch slip rotation speed is set, and the process proceeds to step S306.

  In step S306, it is determined whether or not engine speed ≧ engine all-cylinder ignition completion rotation speed. If YES, the process proceeds to step S307, and if NO, the process proceeds to step S309.

  In step S307, it is determined whether or not the target motor rotational speed ≧ the engine lower limit rotational speed. If YES, the process proceeds to step S308, and if NO, the process proceeds to step S309.

In step S308, the target motor rotational speed is set to the engine lower limit rotational speed (the engine torque controllable rotational speed), and the process proceeds to step S309.
Possible engine torque controllable speeds include the minimum idle speed (about 550 rpm), the required speed of the hydraulic pump (about 1000 rpm), and the engine mount and the engine itself within the resonance region (about 400 rpm). However, in this application, since the second clutch CL2 is slipped when the engine is started, the second clutch CL2 is set to the lowest possible rotational speed so as to maintain the slip.
The lower the target motor rotation speed, the easier the differential rotation of the first clutch CL1 converges to zero. Therefore, by setting the target motor rotation speed low, the time required to complete the engagement of the first clutch CL1 is shortened. Of the torque generated by MG, the torque distributed to the first clutch CL1 is directed to the second clutch CL2 to ensure the driving force.
Further, the engine torque is transmitted to the second clutch CL2 by engaging the first clutch CL1, thereby further securing the driving force.
Note that the engine lower limit rotational speed is set to 100 rpm (rotations / minute) at the time of starting (the input shaft rotational speed of the automatic transmission AT = 0). This is because if the speed is 100 rpm, the slip of the second clutch CL2 can be maintained even when starting.

  In step S309, a proportional portion of the target motor speed is calculated, and the process proceeds to step S310.

  In step S310, the integral of the target motor speed is calculated, and the process proceeds to step S311.

  In step S311, the sum of the proportional portion and the integral portion of the target motor rotational speed is taken as the target motor rotational speed, and the control is terminated.

[Starting time reduction control (second clutch target transmission torque calculation)]
FIG. 7 is a main flow of the second clutch target transmission torque calculation (FIG. 3: step S9).
Steps S21 to S23 are the same as steps S11 to S13 of FIG.

  In step S24, the second clutch target transmission torque calculation is executed while the engine is running, and the control is terminated.

  In step S25, the second clutch target transmission torque calculation is executed during the transition from the EV mode to the HEV mode, and the control is terminated.

  In step S26, the second clutch target transmission torque calculation is executed when shifting from the HEV mode to the EV mode, and the control is terminated.

  In step S27, the second clutch target transmission torque calculation is executed during EV mode traveling, and the control is terminated.

[Starting time reduction control (2nd clutch target transmission torque calculation at engine start)]
FIG. 8 is a target transmission torque calculation flow (FIG. 7: step S25) of the second clutch CL2 when the engine is started.

  At the time of start-up, the initial explosion torque of the engine E is absorbed by slipping the second clutch CL2, but if the input torque from the motor generator MG to the second clutch CL2 is insufficient, the input torque to the second clutch CL2 becomes weak. Therefore, the slip state of the second clutch CL2 cannot be maintained, and the initial explosion torque is transmitted to the transmission, and the driving force may change suddenly.

  That is, when the fastening force of the second clutch CL2 is increased in accordance with the driver's required driving force, the second clutch CL2 can maintain the slip state if the generated torque of the motor generator MG is larger than the required driving force. If the torque generated by the motor generator MG is small, the fastening force of the second clutch CL2 is increased, and the second clutch CL2 cannot maintain the slip state.

  Therefore, in this embodiment, when the required driving force exceeds the output possible torque of the motor generator MG, the fastening force of the second clutch CL2 is limited, and the transmission torque of the second clutch CL2 = the output possible torque of the motor generator MG. (Step S414). As a result, the slip state of the second clutch CL2 is secured, and the shock at the time of the first engine explosion is absorbed.

  On the other hand, if the requested driving force is smaller than the output possible torque of motor generator MG, second clutch CL2 can maintain the slip state, and thus the requested driving force is directly used as the target transmission torque of second clutch CL2 (step S413). ). Note that the engine E is started when the engine speed is detected (see FIG. 4: steps S106, S107, etc.).

  Here, the output possible torque of the motor generator MG depends on the power supplied from the battery 4, and if the output of the battery 4 decreases, the output of the motor generator MG also decreases in conjunction. Further, if (rated) maximum output of motor generator MG> (rated) maximum output of battery 4, motor generator MG cannot originally generate the maximum output.

  Therefore, the current output value of the battery 4 is compared with the design maximum output of the motor generator MG (the rated maximum output in this application), and the larger side is set to the EV mode maximum torque (steps S408, S409, S410). .

  In step S401, it is determined whether or not the differential rotation of the first clutch CL1 ≦ 0 (whether the engine speed is larger). If YES, the process proceeds to step S402, and if NO, the process proceeds to step S407.

  In step S402, it is determined whether engine rotational speed> input shaft rotational speed of automatic transmission AT. If YES, the process is shifted to step S403 because the engine travel mode is selected. If NO, the process proceeds to step S407 because the EV mode or the EV mode is being shifted to the engine travel mode.

  In step S403, the correction amount is added to the previous value of the second clutch torque correction value corresponding to the engine torque in the engine running mode, the second clutch torque correction value is gradually increased, and the process proceeds to step S404.

  In step S404, second clutch target transmission torque = second clutch torque correction value current value + required driving force (determined from the accelerator opening etc.), and the process proceeds to step S405.

  In step S405, it is determined whether or not second clutch differential rotation ≧ slip determination differential rotation (threshold value). If YES, the control is terminated as slip continuation of the second clutch CL2, and if NO, the process proceeds to step S406. .

  In step S406, the second clutch CL2 is in a non-slip state, the actual control mode is set to the HEV mode (the engine E and the motor generator MG are used together), and the control is terminated.

  In step S407, the power that can be output from the battery 4 is converted into the output torque that can be generated when the motor generator MG is supplied (torque that can be battery output), and the process proceeds to step S408.

  In step S408, it is determined whether the battery output possible torque calculated in step S407 and the motor generator maximum power running torque when the supply power is unlimited (the rated maximum torque in FIG. 8) are large or small. If the battery output possible torque is smaller, the process proceeds to step S409, and if not, the process proceeds to step S410.

  In step S409, the maximum torque in the EV mode = battery output possible torque−engine starting torque, and the process proceeds to step S411.

  In step S410, the maximum torque in the EV mode = motor generator MG rated maximum torque−engine starting torque, and the process proceeds to step S411.

  In step S411, it is determined whether or not the maximum torque in the EV mode> the target driving force (see FIG. 2: step S1). If YES, the process proceeds to step S412. If NO, the process proceeds to step S413.

  In step S412, it is determined whether engine speed> startable speed (rotation speed at which engine autonomous rotation is possible). If YES, the process proceeds to step S413, and if NO, the process proceeds to step S414.

  In step S413, the second clutch target transmission torque basic torque is set to the target driving force, and the process proceeds to step S415.

  In step S414, the second clutch target transmission torque basic torque is set to the maximum torque in the EV mode, and the process proceeds to step S415.

  In step S415, it is determined whether or not second clutch differential rotation> slip determination differential rotation (threshold). If YES, the process proceeds to step S416, and if NO, the process proceeds to step S417.

  In step S416, the second clutch CL2 is in the slip continuation state, the second clutch torque correction value previous value + (target differential rotation−actual differential rotation) × slip correction coefficient = second clutch torque correction value current value, and the process proceeds to step S417. Transition.

  In step S417, second clutch target transmission torque = second clutch torque correction value current value + target driving force is set, and the control is terminated.

[Change over time in EV mode-EHV mode transition in start time reduction control]
9 and 10 are time charts at the time of transition from EV to HEV mode. FIG. 9 shows the present application, and FIG. 10 shows a comparative example (an example in which the start time reduction control of the present application is not performed).

(Time t1)
At time t1, the EV mode (driven only by the torque of the motor generator MG) is set, and the output torque of the motor generator MG is the maximum value. In both the present application and the comparative example, the target driving force, the torque of the motor generator MG, and the vehicle speed rise based on the driver's request.

(Time t2)
At time t2, the travel mode is switched to the engine travel mode, and the second clutch target transmission torque decreases to ensure slip.

(Time t3)
At time t3, the accelerator opening becomes constant, and the target driving force reaches a peak value.
In the present application, in order to make the engine start timing earlier, when the differential rotation of the first clutch CL1 (when the differential rotation exceeds a certain value) is detected, the engagement force of the first clutch CL1 is increased. As a result, a large torque is transmitted to the engine E to make it easy to start the engine E (steps S204 → S205 → S207 → S211).
On the other hand, since such control is not performed in the comparative example, the transmission torque of the first clutch CL1 has not yet risen.

(Time t4)
At time t4, the first clutch transmission torque of the comparative example rises, and the rotational speed of the motor generator MG suddenly rises to start the engine E. On the other hand, in this application, since the rotation speed of the motor generator MG is substantially the same as the rotation speed of the automatic transmission AT (see step S304), the rotation speed of the motor generator MG is kept low, and the torque is increased.

(Time t5)
The engine speed rises at time t5.

(Time t6)
At time t6, engine rotation is detected, and in the present application, the engagement force of the first clutch CL1 increases (steps S204 → S205 → S207 → S211), and a large torque is transmitted to the engine E. As a result, the engine speed increases following the speed of motor generator MG.
On the other hand, in the comparative example, the fastening force of the first clutch CL1 does not increase, so the torque input to the engine E does not increase. For this reason, the increase in the engine speed is greatly delayed with respect to the motor generator MG.

(Time t7)
At time t7, in the present application, the engine E is ignited and the engine torque increases rapidly. At substantially the same time, the actual value of the first clutch transmission torque catches up with the target value, and the differential rotation of the first clutch CL1 becomes zero.
In the present application, since the engine speed increases following the motor generator MG speed at time t6, the engine ignition timing is also advanced. Accordingly, in order to increase the second clutch transmission torque (steps S401 → S402 → S403 → S404), the driving force increases.
On the other hand, in the comparative example, since the engine speed remains low at the time t6, the engine E has not yet ignited and no torque is generated.

(Time t8)
At time t8, the torque of the engine E that has already been ignited exceeds the maximum torque of the motor generator MG, and the actual driving force catches up with the target driving force.
On the other hand, in the comparative example, the engine E is ignited at this time, and the torque increases. Since the engine ignition timing is delayed, the increase in driving force is delayed as compared with the present application, and the actual driving force is greatly delayed with respect to the target driving force.

[Effect of the embodiment of the present application]
(1) Engine E, motor generator MG, battery that supplies electric power to motor generator MG, and stores regenerative electric power of motor generator MG, and first clutch CL1 that connects engine E and motor generator MG A second clutch CL2 for connecting the motor generator MG and the automatic transmission AT, an engine E, the motor generator MG, and an integrated controller 10 (control means) for controlling the first and second clutch CL2. By controlling the clutch CL1 and the second clutch CL2, in a control device for a hybrid vehicle that travels by one or both of the engine E and the motor generator MG,
When starting the engine E, the integrated controller 10 ignites the engine E when the engine E reaches a rotation angle at which ignition is possible (steps S106 to S113).

  As a result, the engine E can be immediately ignited at a rotation angle at which the engine E can be ignited, and the engine start time can be shortened to improve the start torque shortage.

  (2) The integrated controller 10 increases the throttle opening when the engine E reaches a speed at which ignition is possible.

  As a result, engine torque is generated promptly after the completion of ignition, and the engine E is rotated by its own torque, and the motor generator torque consumed for increasing the engine rotation is reduced. Therefore, the proportion of the torque generated by motor generator MG allocated to the driving force increases, and the torque at the time of engine start can be ensured.

  (3) When the integrated controller 10 detects the differential rotation of the first clutch CL1 at the start of the engine E, the integrated controller 10 increases the engagement force of the first clutch CL1 (steps S204 → S205 → S207 → S211).

  Thereby, when the differential rotation of the first clutch CL1 is detected, the fastening force of the first clutch CL1 is increased, and a large torque is transmitted to the engine E so that the engine E can be easily started.

  (4) When the differential rotation of the first clutch CL1 is detected after the engine E is started and the rotation of the engine E is detected, the integrated controller 10 stops the increase in the engagement force of the first clutch CL1 ( Step S205 → S206).

  As a result, when the engine speed after start is detected, the transmission torque of the first clutch CL1 is maintained as previously controlled (steps S205 → S206), and the surplus torque of the motor generator MG is driven via the second clutch CL2. Driving force can be secured by turning to force.

  (5) When the target rotational speed of the motor generator MG exceeds the torque controllable speed of the engine E after ignition of the engine E, the integrated controller 10 sets the target rotational speed of the motor generator MG to the torque controllable speed of the engine E. The number is set to a number (steps S306 → S307 → S308).

  As a result, it is possible to suppress an unnecessary increase in the rotational speed of the motor generator MG at the time of starting the engine, and to secure the driving force by turning the surplus torque of the motor generator MG to the driving force via the second clutch CL2. it can.

  (6) The torque controllable engine speed of the engine E is the lower limit value of the engine speed range in which the slip of the second clutch CL2 can be maintained.

The lower the target motor rotation speed, the easier the differential rotation of the first clutch CL1 converges to zero. Therefore, by setting the target motor rotation speed low, the time required to complete the engagement of the first clutch CL1 is shortened. Of the torque generated by MG, the torque distributed to the first clutch CL1 can be directed to the second clutch CL2 to ensure the driving force.
Further, the engine torque can be transmitted to the second clutch CL2 by engaging the first clutch CL1, and the driving force can be further ensured.

  (7) When the driver's required driving force exceeds the torque that can be output from the motor generator MG, the integrated controller 10 limits the engaging force of the second clutch CL2, and uses the transmission torque of the second clutch CL2 as the motor generator MG. The output possible torque is set to be (step S414).

  Thereby, even when the engine is started, the slip state of the second clutch CL2 can be secured, and the shock at the time of the first engine explosion can be absorbed.

  (8) When the driver's required driving force falls below the outputtable torque of the motor generator MG, the integrated controller 10 determines the transmission torque of the second clutch CL2 as the required driving force (step S413).

  In this case, since the second clutch CL2 can maintain the slip state, the required driving force can be directly used as the target transmission torque of the second clutch CL2 to ensure the driving force.

  As mentioned above, although the control apparatus of the hybrid vehicle of this invention has been demonstrated based on the Example, about a specific structure, it is not restricted to this Example, The summary of the invention which concerns on each claim of a claim As long as they do not deviate, design changes and additions are permitted.

It is a system diagram of this application hybrid vehicle. It is a main flow of engine start time reduction control. It is a main flow of engine command calculation (FIG. 2: step S4). It is an engine command calculation flow at the time of transition from EV to HEV mode (FIG. 3: step S15). It is a flow of target transmission torque calculation (FIG. 2: step S7) of the first clutch CL1. It is a target rotation speed calculation (FIG. 2: step S8) flow of the motor generator MG. It is a main flow (FIG. 3: step S9) of a 2nd clutch target transmission torque calculation. It is a target transmission torque calculation flow (FIG. 7: step S25) of the 2nd clutch CL2 at the time of engine starting. It is a time chart at the time of EV-> HEV mode transition in this application. It is a time chart at the time of EV-> HEV mode transfer in a comparative example (example which does not perform start time reduction control of the present application).

Explanation of symbols

E engine CL1 first clutch MG motor generator CL2 second clutch AT automatic transmission 1 engine controller 2 motor controller 3 power control unit 4 battery 6 first clutch hydraulic unit 7 AT controller 8 second clutch hydraulic unit 10 integrated controller

Claims (8)

Engine,
A motor generator;
A battery for supplying electric power to the motor generator and storing regenerative electric power of the motor generator;
A first clutch connecting the engine and the motor generator;
A second clutch connecting the motor generator and the transmission;
Control means for controlling the engine, the motor generator, and the first and second clutches,
By controlling the first clutch and the second clutch, a control device for a hybrid vehicle that travels by one or both of the engine and the motor generator,
The control device ignites the engine when the engine is started, when the engine reaches a rotation angle at which the engine can be ignited. In the hybrid vehicle control device according to claim 1,
The control device for a hybrid vehicle, wherein the control means expands a throttle opening when the engine reaches a revolving speed at which ignition is possible. In the hybrid vehicle control device according to claim 1 or 2,
The control device for a hybrid vehicle, wherein when the differential rotation of the first clutch is detected when the engine is started, the control means increases the fastening force of the first clutch. In the hybrid vehicle control device according to claim 3,
The hybrid vehicle is characterized in that the control means stops the increase in the engagement force of the first clutch when the differential rotation of the first clutch is detected after the engine is started and the rotation of the engine is detected. Control device. In the hybrid vehicle control device according to any one of claims 1 to 4,
When the target rotational speed of the motor generator exceeds the torque controllable speed of the engine after ignition of the engine, the control means sets the target rotational speed of the motor generator to the engine torque controllable speed. A control apparatus for a hybrid vehicle characterized by the above. In the hybrid vehicle control device according to claim 5,
The engine-controllable engine speed is a lower limit value of an engine speed range in which the slip of the second clutch can be maintained. The hybrid vehicle control device according to any one of claims 1 to 6,
The control means limits the fastening force of the second clutch when the driver's required driving force exceeds the output torque of the motor generator, and the transmission torque of the second clutch is set to the output torque of the motor generator. A control device for a hybrid vehicle, characterized in that The hybrid vehicle control device according to any one of claims 1 to 6,
The control device for a hybrid vehicle, wherein when the driver's required driving force falls below an outputable torque of the motor generator, the transmission torque of the second clutch is used as the required driving force.

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