JP5407328B2 - Control device for hybrid vehicle - Google Patents

Description

  The present invention relates to a control apparatus for a hybrid vehicle that starts an engine using a motor as an engine starter motor during traveling in an electric vehicle traveling mode.

  A conventional hybrid vehicle includes an engine and a motor / generator as power sources, a first clutch capable of changing the transmission torque capacity interposed between the engine and the motor / generator, and a transmission from the motor / generator to the drive wheels. The 2nd clutch which can change transmission torque capacity is inserted in the wheel drive system containing. Then, by stopping the engine, releasing the first clutch and engaging the second clutch, it is possible to select the electric vehicle traveling mode using only the power from the motor / generator, and both the first clutch and the second clutch are engaged. Thus, it is possible to select a hybrid vehicle traveling mode based on power from both the engine and the motor / generator (see, for example, Patent Document 1).

In such a hybrid vehicle, during traveling in the electric vehicle traveling mode, the surplus motor torque obtained by subtracting the traveling motor torque used for traveling from the maximum motor torque that can be output by the motor / generator may be used for other than traveling. The speed change of the transmission is controlled so that the torque is maintained at or above the driving motor torque. Here, the non-traveling motor torque refers to engine cranking torque used for starting the engine to be performed by engaging the first clutch when switching from the electric vehicle traveling mode to the hybrid vehicle traveling mode.
JP 2008-105494 A

  However, in the conventional hybrid vehicle control device, if the target drive torque requested by the driver exceeds the torque obtained by subtracting the non-travel motor torque (= engine cranking torque) from the maximum outputable motor torque, the engine Is started (ignited). Accordingly, since the engine is started at the same time as exceeding the engine cranking torque, there is a problem that the number of engine starts increases.

  The present invention has been made paying attention to the above problem, and provides a control device for a hybrid vehicle capable of suppressing the number of engine starts when there is an engine start request during traveling in the electric vehicle traveling mode. For the purpose.

In order to achieve the above object, a control device for a hybrid vehicle according to the present invention has a first clutch that connects and disconnects an engine and a motor, and requests engine start during traveling in an electric vehicle traveling mode that travels only with the power of the motor. If there is, there is provided engine start control means for connecting the first clutch and starting the engine using the motor as an engine start motor.
In the hybrid vehicle control device, the engine start control means independently sets a cranking request determination threshold value and an engine start request determination threshold value for determining cranking and start timing of the engine, and the vehicle is running in the electric vehicle traveling mode. When the target drive torque of the vehicle becomes greater than the cranking request determination threshold, the first clutch is engaged to crank the engine, and after cranking, the target drive torque is greater than the cranking request determination threshold. in the case is kept below the value above engine start request determination threshold, wherein at first clutch is engaged and quasi electric vehicle travel mode that is driven only by the power of the motor without starting the engine, the The vehicle's target drive torque is When falls below the cranking request determination threshold, return to the first said electric vehicle travel mode by opening the clutch, traveling by the quasi-electric vehicle travel mode, the target driving torque of the vehicle is greater than the engine start request determination threshold Then, the engine is started and the hybrid vehicle running mode is entered .

Therefore, in the hybrid vehicle control device of the present invention, when the target drive torque of the vehicle becomes greater than the cranking request determination threshold during traveling in the electric vehicle traveling mode, the engine start control means engages the first clutch. Then the engine is cranked. In a case where the target drive torque is kept below the engine start request determination threshold value that is larger than the cranking request determination threshold value after engine cranking, the motor is not started but the engine is not started. This is a quasi-electric vehicle traveling mode that travels with only the power of When the target drive torque of the vehicle becomes equal to or lower than the cranking request determination threshold during traveling in the quasi-electric vehicle traveling mode, the first clutch is released to return to the electric vehicle traveling mode. When the target drive torque of the vehicle becomes greater than the engine start request determination threshold during traveling in the semi-electric vehicle traveling mode , the engine is started and the hybrid vehicle traveling mode is entered .
That is, the cranking request determination threshold value and the engine start request determination threshold value that determine the cranking and start timing of the engine are set independently. Therefore, in the case where the motor can achieve the target drive torque independently after cranking the engine, that is, in the case where the target drive torque is kept below the engine start request determination threshold after cranking, the quasi-electric vehicle that does not start the engine The travel mode is set. When the target drive torque falls below the cranking request determination threshold during traveling in the semi-electric vehicle traveling mode, the operation returns to the electric vehicle traveling mode .
As a result, when there is an engine start request during traveling in the electric vehicle traveling mode, the number of engine starts can be suppressed.

  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 illustrating a parallel hybrid vehicle (an example of a hybrid vehicle) to which the control device of the first embodiment is applied. Hereinafter, based on FIG. 1, the structure of a drive system and a control system is demonstrated.

  As shown in FIG. 1, the drive system of the parallel hybrid vehicle of the first embodiment includes an engine Eng, a first clutch CL1, a motor / generator MG, a second clutch CL2, an automatic transmission AT, and a final gear FG. And a left drive wheel LT and a right drive wheel RT.

  The hybrid drive system of the first embodiment includes an electric vehicle travel mode (hereinafter referred to as “EV mode”), a hybrid vehicle travel mode (hereinafter referred to as “HEV mode”), and a quasi-electric vehicle travel mode (hereinafter referred to as “ And a driving torque control start mode (hereinafter referred to as “WSC mode”).

  The “EV mode” is a mode in which the first clutch CL1 is opened and the vehicle travels only with the power of the motor / generator MG. The “HEV mode” is a mode in which the first clutch CL1 is engaged and the vehicle travels in any one of the engine travel mode, the motor assist travel mode, and the travel power generation mode. The “quasi-EV mode” is a mode in which the first clutch CL1 is engaged but the engine Eng is turned off and the vehicle travels only with the power of the motor / generator MG. In the “WSC mode”, when starting from “EV mode” or “HEV mode”, the second clutch CL2 is brought into the slip engagement state, and the clutch transmission torque passing through the second clutch CL2 depends on the vehicle state and the driver's operation. This mode starts while controlling the clutch torque capacity so that the required drive torque is determined. “WSC” is an abbreviation for “Wet Start clutch”.

  The engine Eng is capable of lean combustion, and the engine torque is controlled to match the command value by controlling the intake air amount by the throttle actuator, the fuel injection amount by the injector, and the ignition timing by the spark plug.

  The first clutch CL1 is interposed at a position between the engine Eng and the motor / generator MG. As the first clutch CL1, for example, a dry clutch that is always engaged by an urging force of a diaphragm spring is used, and engagement / semi-engagement / release between the engine Eng and the motor / generator MG is performed. If the first clutch CL1 is in the fully engaged state, motor torque + engine torque is transmitted to the second clutch CL2, and if it is in the released state, only motor torque is transmitted to the second clutch CL2. The half-engagement / release control is performed by stroke control with respect to the hydraulic actuator.

  The motor / generator MG has an AC synchronous motor structure, and performs drive torque control and rotation speed control when starting and running, and recovers vehicle kinetic energy to the battery 9 by regenerative brake control during braking and deceleration. Is.

The second clutch CL2 is a wet clutch, and generates transmission torque (clutch torque capacity) according to clutch hydraulic pressure (pressing force). The second clutch CL2 transmits the torque output from the engine Eng and the motor / generator MG (when the first clutch CL1 is engaged) to the left and right drive wheels LT, RT via the automatic transmission AT and the final gear FG. Communicate.
As shown in FIG. 1, the second clutch CL2 is engaged at each gear stage of the automatic transmission AT, in addition to setting an independent clutch between the motor / generator MG and the automatic transmission AT. A clutch or brake used as a frictional engagement element may be used. Alternatively, the position may be set between the automatic transmission AT and the left and right drive wheels LT and RT.

  The automatic transmission AT is a machine that obtains stepped gears, and includes a plurality of planetary gears. The clutch and the brake inside the transmission are respectively engaged / released, and the speed is changed by changing the torque transmission path.

  As shown in FIG. 1, the control system of the parallel hybrid vehicle of the first embodiment includes a second clutch input rotational speed sensor 6 (= motor rotational speed sensor), a second clutch output rotational speed sensor 7, and a high voltage inverter 8. A high-voltage battery 9, an accelerator position sensor 10, an engine speed sensor 11, a clutch oil temperature sensor 12, a stroke position sensor 13, an integrated controller 14, a transmission controller 15, a clutch controller 16, An engine controller 17, a motor controller 18, a battery controller 19, and a brake sensor 20 are provided.

  The high voltage inverter 8 performs DC / AC conversion and generates a driving current for the motor / generator MG. The high voltage battery 9 stores regenerative energy from the motor / generator MG via the high voltage inverter 8.

  The integrated controller 14 calculates a target drive torque from the battery state, the accelerator opening, and the vehicle speed (a value synchronized with the transmission output speed). Based on the result, command values for the actuators (motor / generator MG, engine Eng, first clutch CL1, second clutch CL2, automatic transmission AT) are calculated, and the controllers 15, 16, 17, 18, 19 are calculated. Send to.

  The transmission controller 15 performs shift control so as to achieve a shift command from the integrated controller 14.

  The clutch controller 16 inputs sensor information from the second clutch input rotational speed sensor 6, the second clutch output rotational speed sensor 7, and the clutch oil temperature sensor 12, and the first clutch hydraulic pressure command value from the integrated controller 14. The solenoid valve current is controlled so as to realize the clutch hydraulic pressure (current) command value with respect to the second clutch hydraulic pressure command value.

  The engine controller 17 inputs sensor information from the engine speed sensor 11 and performs engine torque control so as to achieve an engine torque command value from the integrated controller 14.

  The motor controller 18 controls the motor / generator MG so as to achieve the motor torque command value and the motor rotation speed command value from the integrated controller 14.

  The battery controller 19 manages the state of charge of the high voltage battery 9 and transmits the information to the integrated controller 14.

  Next, the processing contents of the integrated controller 14 will be described using the flowchart shown in FIG. Note that the processing content shown in FIG. 2 is executed with constant sampling.

In step S1, the vehicle state measured by another controller such as the battery charge amount SOC, the input rotational speed ω _CL2i of the second clutch CL2, the output rotational speed ω _CL2o of the second clutch CL2, the engine rotational speed ω _e , and the vehicle speed Vsp is received. To do.

In step S2, sensor signals such as the accelerator opening Apo, the first clutch stroke x _CL1 , and the brake SW signal Bsw are measured from the sensors 10, 13, and 20, respectively.

In step S3, it is determined whether or not the first clutch CL1 and the second clutch CL2 are engaged.
First, calculated as follows slip flag Fslip _CL1 from the slip rotation speed of the first clutch CL1 (the absolute value of the difference between the engine speed omega _e and a second clutch input rotational speed ω _CL2i).
1) When | ω _e −ω _CL2i | <ω _{slip_CL1_th} continues for a predetermined time
fslip _CL1 = 0 (fastened) (1)
2) | When ω _e −ω _CL2i | ≧ ω _{slip_CL1_th}
fslip _CL1 = 1 (not fastened) (2)
However,
ω _{slip_CL1_th} : a first clutch engagement determination threshold value.
Next, the slip flag fslip _CL2 is calculated from the slip rotation speed of the second clutch CL2 (the absolute value of the difference between the second clutch input rotation speed _ωCL2i and the output rotation speed _ωCL2o ) as follows.
1) | When ω _CL2i −ω _CL2o |> ω _{slip_CL2_th} continues for a predetermined time
fslip _CL2 = 1 (not fastened) (3)
2) | When ω _CL2i −ω _CL2o | ≦ ω _{slip_CL2_th}
fslip _CL2 = 0 (fastened) (4)
However,
ω _{slip_CL2_th} : a second clutch engagement determination threshold value.

In step S4, it is determined whether or not cranking of the engine Eng has been completed.
Cranking completion flag fcrank_fin from slip flag Fslip _CL1 and the engine rotational speed omega _e of the first clutch CL1 is calculated as follows.
1) When fslip _CL1 = 0 and ω _e ≧ ω _{e_idle}
fcrank_fin = 1 (cranking complete) (5)
2) Other than above
fcrank_fin = 0 (cranking is incomplete) (6)
However,
ω _{e_idle} : It is an idle possible determination threshold value.

In step S5, the target drive torque Td ^* is calculated from the accelerator opening Apo and the vehicle speed Vsp. The target drive torque Td ^* is calculated based on, for example, a target drive torque calculation map as shown in FIG.

In step S6, the target travel mode Mode _drive ^* is calculated. Hereinafter, a description will be given with reference to the flowchart shown in FIG.

In step S601, the cranking request determination threshold T _{d_th_A} and the engine start request determination threshold T _{d_th_B} (> T _{d_th_A} ), which are the points of the present _plan, are calculated. First, the cranking request determination threshold T _{d_th_A} is calculated based on the following equation.
T _{d_th_A} = T _{m_max} −T _crank (7)
However,
T _{m_max} : Maximum motor torque
T _crank : Minimum torque required for cranking the engine Eng Based on the map shown in Fig. 5, the engine start request determination threshold T _{d_th_B} is calculated from the change amount ΔApo of the accelerator opening per unit time and the battery charge SOC. To do. If it calculates, it will progress to step S602.
Here, the engine start request determination threshold value T _{d_th_B} is a value that is not less than the cranking request determination threshold value T _{d_th_A and not} more than (T _{m_max} −T _{CL1_on} ) as shown in the map characteristics of FIG. The larger the change amount ΔApo per hour, the smaller the value. Also, the higher the battery charge SOC, the larger the value. T _{CL1_on} is the engagement torque of the first clutch CL1.

In step S602, it is determined from the battery charge amount SOC whether or not the engine should be forcibly started for power generation. If the battery charge SOC is smaller than the predetermined value _{SOC_th_l} , it is determined that the engine should be started, and the process proceeds to step S609. Otherwise, the process proceeds to step S603.

In step S603, it is determined whether or not the previous target driving mode Mode _drive ^* _z1 is 2 (HEV mode). If 2 (HEV mode), the process proceeds to step S606, otherwise the process proceeds to step S604.

In step S604, it is determined whether or not the target drive torque Td ^* is equal to or less than a cranking request determination threshold value _{Td_th_A} . If so, the process proceeds to step S607, otherwise the process proceeds to step S605.

In step S605, it is determined whether or not the target drive torque Td ^* is equal to or less than the engine start request determination threshold value _{Td_th_B} . If so, the process proceeds to step S608, otherwise the process proceeds to step S609.

In step S606, it is determined whether or not the engine Eng should be stopped from the accelerator opening Apo and the battery charge amount SOC. If accelerator opening Apo is 0 (accelerator OFF) and battery charge SOC is SOC _{_th_h} (> SOC _{_th_l} ) or more, it is determined that engine Eng should be stopped, and to step S607, otherwise. move on.

In step S607, 0 (EV mode) is set in the target travel mode Mode _drive ^*, and the process proceeds to step S610.

In step S608, 1 (semi-EV mode) is set in the target travel mode Mode _drive ^*, and the process proceeds to step S610.

In step S609, 2 (HEV mode) is set in the target travel mode Mode _drive ^*, and the process proceeds to step S610.

In step S610, the current target travel mode Mode _drive ^* is substituted into the previous (pre-sampling) target travel mode Mode _drive ^* _z1.

In step S7, the target control mode Mode _CL1 ^* of the first clutch CL1 is calculated. Hereinafter, a description will be given using the flowchart shown in FIG.

In step S701, it is determined whether or not the target travel mode Mode _drive ^* is 0 (EV mode). If it is 0, the process proceeds to step S703. Otherwise, the process proceeds to step S702.

In step S702, it is determined whether or not the first clutch CL1 should be engaged. If the slip rotation speed of the first clutch CL1 is equal to or less than a predetermined value ω _{slip_CL1_th2} (> ω _{slip_CL1_th} ), it is determined that the first clutch CL1 should be engaged, and the process proceeds to step S704, otherwise the process proceeds to step S705.

In step S703, 0 (release mode) is set to the target control mode Mode _CL1 ^* of the first clutch CL1.

In step S704, 2 (engagement mode) is set to the target control mode Mode _CL1 ^* of the first clutch CL1.

In step S705, 1 (slip mode) is set to the target control mode Mode _CL1 ^* of the first clutch CL1.

In step S8, the target control mode Mode _CL2 ^* of the second clutch CL2 is calculated. Hereinafter, a description will be given using the flowchart shown in FIG.

In step S801, it is determined whether or not the target travel mode Mode _drive ^* is 0 (EV mode). If it is 0, the process proceeds to step S802. Otherwise, the process proceeds to step S803.

In step S802, it is determined whether or not the second clutch CL2 should be engaged. If the vehicle speed Vsp is equal to or less than the predetermined value _{Vsp_th} or the target drive torque Td ^* is equal to or less than 0, it is determined that the engagement should be performed, and the process proceeds to step S807, otherwise the process proceeds to step S808.

  In step S803, it is determined whether cranking of the engine Eng is completed. If fcrank_fin = 1, it is determined that cranking is complete, and the process proceeds to step S804. Otherwise, the process proceeds to step S808.

In step S804, it is determined whether or not the vehicle speed Vsp is equal to or higher than the lockup possible vehicle speed _{Vsp_th_lu} . If it is _{Vsp_th_lu} or more, the process proceeds to step S805, and otherwise, the process proceeds to step S806.

In step S805, it is determined whether or not the second clutch CL2 should be engaged. If the slip rotation speed of the second clutch CL2 is equal to or less than the predetermined value ω _{slip_CL2_th2} (> ω _{slip_CL2_th} ), it is determined that it should be _engaged, and the process proceeds to step S807, otherwise the process proceeds to step S808.

In step S806, it is determined whether or not the second clutch CL2 should be released. If the target drive torque Td ^* is 0 or less, it is determined that the target drive torque Td ^* should be released, and the process proceeds to step S809. Otherwise, the process proceeds to step S808.

In step S807, 2 (engagement mode) is set to the target control mode Mode _CL2 ^* of the second clutch CL2.

In step S808, 1 (slip mode) is set to the target control mode Mode _CL2 ^* of the second clutch CL2.

In step S809, 0 (disengagement mode) is set to the target control mode Mode _CL2 ^* of the second clutch CL2.

In step S9, a gear position command value SHIFT ^* is calculated from the accelerator opening Apo and the vehicle speed Vsp. The shift speed command value SHIFT ^* is calculated based on, for example, a shift speed command value calculation map as shown in FIG.

In step S10, the engine torque command value Te ^* is calculated as follows based on the target travel mode, the target drive torque Td ^* , and the engine speed. Various calculation methods can be considered for the engine torque command value. In this embodiment, the motor torque is used as much as possible, and the engine torque is set to supplement the shortage with respect to the target drive torque.
1) EV mode
Te ^* = 0 (8)
2) In quasi-EV mode
Te ^* = 0 (9)
3) HEV mode ω _e <ω _{e_fire}
Te ^* = 0 (10)
When ω _e ≧ ω _{e_fire}
Te ^* = Td ^* −T _{m_max} (11)
However,
ω _{e_fire} : An engine start possibility determination threshold value.

In step S11, a motor torque command value Tm ^* is calculated. Hereinafter, a description will be given using the flowchart shown in FIG.

In step S1101, it is determined whether or not the target control mode Mode _CL2 ^{* of} the second clutch CL2 is 2 (engaged mode). If it is 2, the process proceeds to step S1102, otherwise the process proceeds to step S1103.

In step S1102, it is determined whether the motor / generator MG should control the slip rotation speed. If the slip flag fslip _CL2 is 1 (not fastened), the motor / generator MG determines that the slip rotation speed should be controlled, and the process proceeds to step S1103. Otherwise, the process proceeds to step S1106.

In step S1103, the target rotational speed value ω _CL2i ^* of the motor / generator MG is calculated from the target travel mode Mode _drive ^*, the output rotational speed ω _CL2o of the second clutch CL2, and the accelerator opening Apo.
First, the slip rotation speed target value ω _{CL2_slp} ^* of the second clutch CL2 is calculated based on the following.
1) When Mode _drive ^* = 0 (EV mode) ω _{CL2_slp} ^* = ω _{CL2_slp_EV} (12)
However,
ω _{CL2_slp_EV} : slip rotation speed for EV mode (fixed value comprehensively determined from the durability of the second clutch CL2 and motor rotation speed control performance)
2) When Mode _drive ^* ≠ 0 (except EV mode) and fcrank_fin = 1 (cranking complete) ω _{CL2_slp} ^* = f _{CL2_slp_CL1OP} (ω ₀ , Apo) (13)
Here, f _{CL2_slp_CL1OP} () is a function having the second clutch output rotational speed measurement value ω ₀ and the accelerator opening Apo as inputs. Actually, for example, the map is set as shown in FIG. By doing in this way, desired lockup rotation speed (output rotation speed from which a slip becomes 0) can be set according to an accelerator opening.
3) When Mode _drive ^* ≠ 0 (except EV mode) and fcrank_fin = 0 (cranking incomplete) ω _{CL2_slp} ^* = f _{CL2_slp_CL1OP} (ω ₀ , Apo) + f _{CL2_Δωslp} (T _{m_crank} ) (14)
Here, f _{CL2_Δωslp} () is a function for calculating the slip rotation speed increase amount for cranking, and cranking distribution motor torque T _{m_crank} (maximum output possible motor torque T _{m_max} and second clutch torque capacity command value T _{CL2_base} ^* difference) as input. Actually, for example, by using a map as shown in FIG. 10 (b), when the cranking distribution motor torque decreases, the target second clutch slip rotation speed is increased (increase the increase amount). To do. As a result, the disturbance from the first clutch CL1 cannot be completely canceled, and sudden engagement can be prevented even if the rotational speed decreases, and as a result, cranking can be performed without causing acceleration fluctuations.
Next, from the slip rotation speed target value ω _{CL2_slp} ^* and the output rotation speed ω _CL2o of the second clutch CL2,
ω _CL2i ^* = ω _{CL2_slp} ^* + ω _o (15)
The basic input rotational speed target value ω _CL2i ^* is calculated using the following equation.

In step S1104, the motor torque command value Tm ^* when the second clutch CL2 is engaged is controlled.
1) When Mode _drive ^* = 0 (EV mode)
Tm ^* = Td ^* (16)
2) When Mode _drive ^* = 1 (semi-EV mode)
Tm ^* = Td ^* + T _{CL1_on} (17)
However,
T _{CL1_on} : Engine friction torque (preset)
3) When Mode _drive ^* = 2 (HEV mode)
Tm ^* = Td ^* + T _{CL1_on} −T _e ^* (18)
Calculation is performed as described above.

In step S1105, the motor torque command value Tm ^* for slip control is calculated so that the input rotation speed target value ω _CL2i ^{* of} the second clutch CL2 matches the input rotation speed ω _CL2i . There are various calculation (control) methods. For example, calculation is performed based on the following expression using PI control. The actual calculation is performed using a recurrence formula obtained by discretization by Tustin approximation or the like.
_{^{Tm * = {(K Pm s}} + K Im) / s} · (ω CL2i * -ω CL2i) (19)
However,
K _Pm : Proportional gain for motor control
K _Im : Motor control integral gain s: Differential operator.

In step S1106, a motor torque command value Tm ^* for slip transition control is calculated based on the following equation.

Tm ^* = T _{m_z1} ^* + ΔT _{m_slp} (20)
However,
T _{m_z1} ^* : Previous value of motor torque command value ΔT _{m_slp} : Torque capacity change rate at transition from engagement to slip (Set larger as accelerator opening Apo is larger)
It is.

In step S12, the first clutch torque capacity command value T _CL1 ^* is calculated as follows.
1) When Mode _CL1 ^* = 0 (open mode)
T _CL1 ^* = 0 (21)
2) When Mode _CL1 ^* = 1 (slip mode)
T _CL1 ^* = T _crank (22)
3) When Mode _CL1 ^* = 2 (fastening mode)
T _CL1 ^* = T _{CL1_max} (23)
However,
T _{CL1_max} : The first clutch maximum torque capacity.

In step S13, the second clutch torque capacity command value T _CL2 ^* is calculated as follows. This will be described below with reference to the flowchart shown in FIG.

In step S1301, it is determined whether or not the target control mode Mode _CL2 ^{* of} the second clutch CL2 is 2 (engaged mode). If it is 2, the process proceeds to step S1304. Otherwise, the process proceeds to step S1302.

In step S1302, it is determined whether or not the target control mode Mode _CL2 ^{* of} the second clutch CL2 is 1 (slip mode). If it is 1, the process proceeds to step S1303. Otherwise, the process proceeds to step S1308.

In step S1303, it is determined whether the second clutch CL2 is slipping. If the slip flag fslip _CL2 is 1 (non-engaged), it is determined that the vehicle is slipping, and the process proceeds to step S1304. Otherwise, the process proceeds to step S1307.

In step S1304, the basic second clutch torque capacity command value T _{CL2_base} ^* is calculated as follows.
1) When fcrank_fin = 0 (cranking is not complete)
T _{CL2_base} ^* = min (T _{d_th_A} , Td ^* ) (24)
However,
min (A, B): Outputs the smaller value of A and B
T _{d_th_A} : _Cranking request judgment threshold
2) When fcrank_fin = 1 (cranking complete)
T _{CL2_base} ^* = Td ^* (25)
And

In step S1305, the second clutch torque capacity command value T _CL2 ^* for engagement control is calculated based on the following equation.
i) When T _{CL2_z1} ^* <T _{CL2_max}
T _CL2 ^* = T _{CL2_z1} ^* + ΔT _{CL2_LU} (26)
ii) When T _{CL2_z1} ^* ≧ T _{CL2_max}
T _CL2 ^* = T _{CL2_max} (27)
However,
T _{CL2_max} : Second clutch maximum torque capacity ΔT _{CL2_LU} : Rate of torque capacity change at the transition from slip to engagement
T _{CL2_z1} ^* : The previous value of the second clutch torque capacity command value.

In step S1306, a second clutch torque capacity command value T _CL2 ^* for slip control is calculated. Hereinafter, the second clutch control system shown in FIG. 12 will be described. This control system is designed with a two-degree-of-freedom control method consisting of feedforward (F / F) compensation and feedback (F / B) compensation. Various design methods can be considered for the F / B compensator, but this time PI control is an example.
First, based on the phase compensation filter G _FF (s) shown in the following equation, phase compensation is applied to the basic second clutch torque capacity command value T _{CL2_base} ^*, and the F / F torque capacity command value T _{CL2_FF} of the second clutch CL2 is _obtained . Calculate. The actual calculation is performed using a recurrence formula obtained by discretization by Tustin approximation or the like.
T _{CL2_FF} / T _{CL2_base} ^* = G _FF (s) = (τ _CL2 · s + 1) / (τ _{CL2_ref} · s + 1) (28)
However,
τ _CL2 : Second clutch model time constant τ _{CL2_ref} : _Reference response time constant for second clutch control.

Next, according to the target travel mode Mode _drive ^* , the second clutch torque capacity target value T _{CL2_t} is set as _follows :
1) When Mode _drive ^* = 0 (EV mode)
T _{CL2_t} = T _{CL2_base} ^* (29)
2) When Mode _drive ^* ≠ 0 (except EV mode) and fcrank_fin = 1 (cranking complete)
T _{CL2_t} = T _{CL2_base} ^* + T _{CL1_on} −Te ^* (30)
3) When Mode _drive ^* ≠ 0 (except EV mode) and fcrank_fin = 0 (cranking incomplete)
T _{CL2_t} = T _CL1 ^* + T _{CL2_base} ^* (31)
It calculates by the formula of

Supplementary explanation: The second clutch torque capacity target value _{TCL2_t} represents the torque output by the motor torque during slip control in an ideal state. The F / B compensator corrects the torque capacity of the second clutch so that _{TCL2_t} and the motor torque command value during slip control (substantially the same value as the actual motor torque) match in a steady state.

Next, based on the second clutch _reference model G _{CL2_REF} (s) shown in the following equation, the second clutch torque capacity reference value T _{CL2_ref} is
(T _{CL2_ref} / T _{CL2_t} ) = G _{CL2_REF} (s) = 1 / (T _{CL2_ref} · s + 1) (32)
It calculates by the formula of

Next, from the second clutch torque capacity reference value T _{CL2_ref} and the motor torque command value Tm ^* for rotational speed control described above, the F / B torque capacity command value T _{CL2_FB} of the second clutch CL2 is _calculated based on the following equation:
T _{CL2_FB} = {(K _PCL2 s + K _ICL2 ) / s} x (T _{CL2_ref} -Tm ^* ) (33)
However,
K _PCL2 : Proportional gain for second clutch control
K _ICL2 : Calculated using the integral gain for second clutch control.

  Further, by considering the torque (inert torque) generated by the change in the input rotational speed as in the following equation, the torque capacity can be accurately controlled even when the input rotational speed is changing.

T _{CL2_FB} = {(K _PCL2 s + K _ICL2 ) / s} x (T _{CL2_ref} −Tm ^* _{−Tine_est} ) (34)
Here, _{Tine_est} is an inertia torque estimation value, for example, the input rotational speed change amount (differential value) is multiplied by an inertia moment around the input shaft (variable depending on whether the first clutch is engaged or not engaged). Ask.
Then, the F / F torque capacity command value T _{CL2_FF} and the F / B torque capacity command value T _{CL2_FB} of the second clutch CL2 are added to calculate a final second clutch capacity command value T _CL2 ^* for slip control.

In step S1307, the second clutch torque capacity command value T _CL2 ^* for slip transition control is calculated based on the following equation.

T _CL2 ^* = T _{CL2_z1} ^* −ΔT _{CL2_slp} (35)
However,
T _{CL2_z1} ^* : Previous value ΔT _{CL2_slp of} the second clutch torque capacity command value: Torque capacity change rate at the time of engagement → slip transition.

In step S1308, the second clutch torque capacity command value T _CL2 ^* for release control is
T _CL2 ^* = 0 (36)
Calculate based on the following formula.

In step S14, a current command value I _CL1 ^* to the solenoid valve that controls the hydraulic pressure applied to the first clutch CL1 is calculated from the first clutch torque capacity command value T _CL1 ^* . Hereinafter, a description will be given using the flowchart shown in FIG.

In step S1401, the first clutch stroke target value x _CL1 ^* is calculated from the first clutch torque capacity command value T _CL1 ^* using a map (FIG. 14) created based on the clutch torque capacity-stroke characteristic acquired in advance.

In step S1402, the hydraulic pressure command value P _CL1 ^* is calculated from the stroke command value x _CL1 ^* and the measured stroke value based on the following. In the present embodiment, a two-degree-of-freedom control method is employed (FIG. 15), similar to the control of the second clutch CL2 (see FIG. 12).
First, from the stroke command value, the F / F hydraulic pressure command value P _{CL1_FF} is _calculated using a phase compensation filter consisting of the inverse system of the reference response transfer characteristic as shown in the following formula and the control target transfer characteristic after hydraulic pressure correction described later. Calculate.
(P _{CL1_FF} ) / (x _sCL1 ^* ) = G _{CL1_FF} (s) = {(Ms ² + Cs + K _{CL1_ref} ) ω ² _{CL1_ref} } / {s ² + 2ζ _{CL1_ref} ω _{CL1_ref} s + ω ² _{CL1_ref} } (37)
It becomes.
However,
C: First clutch mechanism viscosity coefficient
K _{CL1_ref} : Spring constant to be controlled after hydraulic pressure correction ζ _{CL1_ref} : First clutch reference response damping coefficient ω _{CL1_ref} : First clutch reference response natural frequency
M: clutch mass.

Next, the stroke reference value x _{sCL1_ref} is calculated from the first clutch stroke command value x _sCL1 ^* using a filter representing the reference response transmission characteristic as shown in the following equation. The arithmetic expression is
(x _{sCL1_ref} ) / (x _sCL1 ^* ) = G _{CL1_ref} (s) = (ω ² _{CL1_ref} ) / (s ² + 2ζ _{CL1_ref} ω _{CL1_ref} s + ω ² _{CL1_ref} ) (38)
It becomes.

Then, from the deviation x _{SCL1_err} stroke reference value x _{SCL1_ref} and the stroke measured value x _SCL1, it calculates the F / B pressure command value P _{CL1_FB} based on the following equation. The arithmetic expression is
(P _{CL1_FB} ) / (x _{sCL1_err} ) = G _{CL1_FB} (s) = (K _{Pgain_CL1} s + K _{Igain_CL1} + K _{Dgain_CL1} s ² ) / s (39)
It becomes.
However,
K _{Pgain_CL1} : Proportional gain
K _{Igain_CL1} : Integral gain
K _{Dgain_CL1} : Differential gain. Finally, the F / F hydraulic pressure command value P _{CL1_FF} and the F / B hydraulic pressure command value P _{CL1_FB} are added to _obtain a hydraulic pressure command value P _CL1 ^* .

In step S1403, the hydraulic pressure command value is corrected so that the inclination of the reaction force (hydraulic pressure) -stroke characteristic of the clutch mechanism (the spring characteristic of the diaphragm spring) becomes a characteristic desired by the designer. Hereinafter, a detailed method will be described.
From the _difference between the first clutch hydraulic pressure estimated value P _{CL1_est} calculated using the map created based on the characteristics shown in FIG. 14 from the stroke measurement value x _sCL1 and the reaction force reference value P _{CL1_ref} calculated using the standard spring characteristics, The hydraulic pressure correction value P _{CL1_hosei} is calculated.

P _{CL1_hosei} = P _{CL1_ref} −P _{CL1_est} = K _ref・ x _sCL1 −f _xCL1-p (x _sCL1 ) (40)
However,
f _xCL1-p (): A function indicating the hydraulic pressure-stroke characteristic.
The final hydraulic pressure command value P _{CL1_com} is calculated from the hydraulic pressure correction value P _{CL1_hosei} calculated as described above and the hydraulic pressure command value P _CL1 ^* .

P _{CL1_com} = P _CL1 ^* −P _{CL1_hosei} (41)
It calculates by the formula of

In step S1404, the current command value I _CL1 ^* is calculated from the final hydraulic pressure command value P _{CL1_com} using a map (see FIG. 16B) created based on previously acquired characteristics, as in the second clutch CL2 described later. .

In step S15, a current command value I _CL2 ^* to the solenoid valve for controlling the hydraulic pressure applied to the second clutch CL2 is calculated from the second clutch torque capacity command value T _CL2 ^* . Actually, the calculation is performed using a map (FIGS. 16A and 16B) created based on characteristics acquired in advance. Thereby, even when the clutch torque capacity has a non-linear characteristic with respect to the hydraulic pressure or current, the control target can be regarded as linear, and thus the linear control theory as described above can be applied.

  In step S <b> 16, the calculated command value is transmitted to each control controller 15, 16, 17, 18.

Next, the operation will be described.
First, the “problem of engine start control in the comparative example” will be described, and then the operation in the hybrid vehicle control device of the first embodiment will be referred to as “engine start count suppression action” and “engine start count corresponding to accelerator operation”. The description will be divided into “suppression action” and “engine start frequency suppression action corresponding to the battery charge amount”.

[Problems of engine start control in comparative example]
FIG. 17 shows the accelerator opening, target drive torque, motor rotational speed, CL2 output rotational speed, engine rotational speed, engine speed when the engine transitions from "EV mode" to "HEV mode" in the comparative example. It is a time chart which shows each characteristic of the 2nd clutch torque capacity, the 1st clutch torque capacity, motor torque, and engine torque. Hereinafter, the engine start control operation will be described with reference to FIG.

  As in the first embodiment, the hybrid vehicle according to the comparative example has an automatic transmission including an engine, an engine starting clutch (first clutch), a motor / generator, and a clutch (second clutch) capable of controlling driving force. Is a system in which machines are arranged in order. In this system, the motor torque during travel in “EV mode” is limited to the difference between the maximum motor torque (maximum torque that the motor can output) and cranking torque (torque required to increase engine rotation). By leaving a margin for the cranking torque in the motor torque, the driving torque loss due to the cranking is prevented during traveling in the “EV mode”.

  However, the engine start control in this comparative example is a series of control of cranking and engine start (ignition). For this reason, when the target drive torque (set from the accelerator opening and the vehicle speed) becomes larger than the difference between the maximum motor torque and the cranking torque (FIG. 17: at time t1), the motor torque is left with a margin for the cranking torque. become unable. Therefore, cranking is started while leaving a margin for the cranking torque in the motor torque (FIG. 17: at time t3), and the engine starts whenever the engine speed rises above the engine startable speed. (FIG. 17: time t4).

  As a result, during traveling in the “EV mode”, based on the engine cranking request (FIG. 17: time t1), the slip determination of the second clutch (FIG. 17: time t2) and cranking start (FIG. 17). : After time t3), the engine starts whenever the engine speed rises above the engine startable speed (FIG. 17: at time t4), and the first clutch is fully engaged (FIG. 17: time t5). ), Mode transition to “HEV mode”. For this reason, the number of engine starts increases. And when starting the engine, fuel is used much as a measure against NOx, so the more the engine is started, the worse the fuel consumption.

[Engine start frequency suppression action (point 1)]
FIG. 18 is a condition comparison diagram showing the cranking start condition with respect to the target drive torque in the comparative example, the cranking start condition with respect to the target drive torque in Example 1, and the engine start condition. FIG. 19 shows the accelerator opening, target drive torque, motor rotational speed, CL2 output rotational speed, engine rotational speed when the mode is changed from “EV mode” to “quasi-EV mode” in the first embodiment. It is a time chart which shows each characteristic of number, 2nd clutch torque capacity, 1st clutch torque capacity, motor torque, and engine torque. Hereinafter, the operation for suppressing the number of engine starts will be described with reference to FIGS.

A case will be described in which a cranking request is issued at time t1 ′ in FIG. 19 when the target drive torque Td ^* is increased by the accelerator depressing operation during traveling in the “EV mode”.

In this case, while the target drive torque Td ^* is _{equal to} or less than the cranking request determination threshold T _{d_th_A} , in the flowchart of FIG. 4, the process proceeds from step S601 to step S602 → step S603 → step S604 → step S607. _drive ^* is set to Mode _drive ^* = 0 (EV mode). In the flowchart of FIG. 6, the first clutch CL1 proceeds from step S701 to step S703, and the target control mode Mode _CL1 ^* is set to Mode _CL1 ^* = 0 (disengagement mode). In the flowchart shown in FIG. 7, the second clutch CL2 proceeds from step S801 to step S802 to step S808, and the target control mode Mode _CL2 ^* is set to Mode _CL2 ^* = 1 (slip mode). The motor / generator MG proceeds from step S1101 to step S1102 to step S1106 in the flowchart of FIG. 9, and the motor torque command value for slip transition control is calculated.

  Next, when the slip of the second clutch CL2 is determined at time t2 ′ in FIG. 19, the flow proceeds from step S1101 to step S1102 to step S1103 to step S1105 in the flowchart in FIG. A torque command value is calculated. That is, the second clutch CL2 is brought into a slip engagement state in advance so as to prevent a shock associated with cranking or starting of the engine Eng.

Next, when the target drive torque Td ^* exceeds the cranking request determination threshold value _{Td_th_A} at time t3 ′ in FIG. 19, in the flowchart in FIG. 4, step S601 → step S602 → step S603 → step S604 → step S605 → step S608. , The target travel mode Mode _drive ^* is set to Mode _drive ^* = 1 (semi-EV mode). The first clutch CL1 proceeds from step S701 to step S702 to step S705 in the flowchart of FIG. 6, and the target control mode Mode _CL1 ^* is set to Mode _CL1 ^* = 1 (slip mode). In the flowchart shown in FIG. 7, the second clutch CL2 proceeds from step S801 to step S803 to step S808, and until the target control mode Mode _CL2 ^* completes cranking of the engine Eng, Mode _CL2 ^* = 1 (slip Mode). That is, cranking of the engine Eng is started at time t3 ′ by the slip engagement of the first clutch CL1.

After that, when the target drive torque Td * does not exceed the engine start request determination threshold value Td_th_B and the individual travel using only the motor / generator MG is possible after the cranking, step S601 → The process proceeds from step S602 to step S603 to step S604 to step S605 to step S608, and the target travel mode Modedrive * remains set to Modedrive * = 1 (semi-EV mode). When the first clutch engagement condition is satisfied, the first clutch CL1 proceeds from step S701 to step S702 to step S704 in the flowchart of FIG. 6, and the target control mode ModeCL1 * is set to ModeCL1 * = 2 (engagement mode). Is done. By the engagement control of the first clutch CL1, the first clutch CL1 is completely engaged at time t5 ′ in FIG. 19, and the “quasi-EV mode” is shifted from during cranking.

Thereafter, when the second clutch engagement condition is satisfied, the second clutch CL2 proceeds to step S801 → step S803 → step S804 → step S805 → step S807 in the flowchart shown in FIG. 7, and the target control mode Mode _CL2 ^* is Mode _CL2 ^* = 2 (engaged mode) is switched, and at time t6 in FIG. 19, the mode shifts to the “quasi-EV mode” in which the first clutch CL1 and the second clutch CL2 are completely engaged.

On the other hand, when the target drive torque Td ^* exceeds the cranking request determination threshold T _{d_th_A} and exceeds the engine start request determination threshold T _{d_th_B} (> T _{d_th_A} ), step S601 → step S602 → step S603 in the flowchart of FIG. The process proceeds from step S604 to step S605 to step S609, the target travel mode Mode _drive ^* is switched to Mode _drive ^* = 2 (HEV mode), and the engine Eng is started as in the comparative example.

As described above, in the engine start control according to the first embodiment, as shown in FIG. 18, the first drive torque Td ^* is first when the cranking request determination threshold value T _{d_th_A} (hereinafter _{referred to} as the predetermined value A) becomes larger. The clutch CL1 is slip-engaged and cranked, and after cranking, the engine is started (ignited) when the target drive torque Td ^* becomes larger than the engine start request determination threshold T _{d_th_B} (hereinafter _{referred to} as a predetermined value B). I have to.
In this way, by setting the engine Eng cranking and start timing independently, the motor / generator MG can independently achieve the target drive torque Td ^* after cranking (at time t3 ′ in FIG. 19). Since the engine is not started, the number of engine Eng starts can be suppressed. In other words, even when a large amount of fuel is used to prevent NOx when starting the engine, the number of engine starts is reduced, so that deterioration of fuel consumption can be suppressed.

In the engine start control of the first embodiment, as shown in FIG. 18, a predetermined value A as a cranking request determination threshold is set to 0 <A ≦ (difference between maximum motor torque and cranking torque).
Therefore, the cranking timing of the engine Eng is the same as that of the comparative example as shown in FIG. 18, and when it is determined that the motor / generator MG cannot travel alone, the comparative example and Similarly, since the engine Eng is started and shifted to the “HEV mode” and travels with the engine Eng and the motor / generator MG, the drivability is not impaired. Further, compared with the case where the predetermined value A is set to 0 (when the engine Eng is always rotated), the loss for rotating the engine Eng is reduced.

In the engine start control of the first embodiment, as shown in FIG. 18, a predetermined value B as an engine start request determination threshold is set to A <B <(difference between maximum motor torque and engine friction torque). Here, the “engine friction torque” is a torque required to rotate the engine Eng at a constant rotation, and is a value smaller than the cranking torque.
If the target drive torque is equal to or greater than the maximum EV possible torque (difference between the maximum motor torque and the engine friction torque), the time until the target drive torque exceeds the predetermined value B and reaches the maximum EV possible torque is greater than the engine start time. If it is short, there is a possibility that the target drive torque cannot be realized because the engine start is not in time immediately after the maximum EV possible torque.
On the other hand, by setting the predetermined value B to A <B <(difference between the maximum motor torque and the engine friction torque), the engine start is completed before reaching the maximum motor torque (= EV possible maximum torque). A driving torque Td ^* can be realized.

[An engine start frequency suppression action corresponding to accelerator operation (point 2)]
FIG. 20 is a condition comparison diagram showing the cranking start condition and engine start condition for the target drive torque at point 1 of the first embodiment and the cranking start condition and engine start condition for the target drive torque at point 2 of the first embodiment. It is. Hereinafter, the engine start frequency suppression action corresponding to the accelerator operation will be described with reference to FIG.

  In the engine start control of the first embodiment, as shown in FIG. 5, the smaller the accelerator opening change amount ΔApo, the larger the predetermined value B, in other words, the predetermined value B is set to the difference between the maximum motor torque and the engine friction torque. I try to get closer.

  As described above, if the target drive torque is equal to or greater than the EV possible maximum torque (difference between the maximum motor torque and the engine friction torque), the time until the target drive torque exceeds the predetermined value B and reaches the EV possible maximum torque is set. If it is shorter than the engine start time, there is a possibility that the target drive torque cannot be realized because the engine start is not in time immediately after it becomes larger than the maximum EV possible torque.

On the other hand, in the first embodiment, when the accelerator opening change amount ΔApo is large, the predetermined value B is set to a value smaller than the EV possible maximum torque with a margin, thereby ensuring the engine start time, thereby achieving the target drive torque Td ^*. Can be realized. Further, when the accelerator opening change amount ΔApo is small, as shown in FIG. 20, the number of engine starts can be further suppressed by reducing the margin (increasing the predetermined value B).

[An engine start number suppression action corresponding to the battery charge (point 3)]
FIG. 21 is a condition comparison diagram showing the cranking start condition and engine start condition for the target drive torque at point 1 of the first embodiment and the cranking start condition and engine start condition for the target drive torque at point 3 of the first embodiment. It is. Hereinafter, the engine start frequency suppression action corresponding to the battery charge amount will be described with reference to FIG.

  In the engine start control according to the first embodiment, as shown in FIG. 5, the lower the battery charge SOC, the smaller the predetermined value B, in other words, the closer to the predetermined value A.

  For example, if the battery charge SOC decreases to such an extent that the engine does not start for a long time and the EV mode cannot be operated, the engine is forcibly started regardless of the accelerator operation for power generation. If the engine is started at the same timing, the driver may feel uncomfortable because it does not match the feeling of accelerator operation.

On the other hand, in the first embodiment, the engine is started after the target drive torque Td ^* reaches the predetermined value B even if the battery charge amount SOC decreases. In other words, the engine is started after the target drive torque Td ^* is increased by the accelerator ON operation. Thus, as the battery charge SOC is on the lower side, the engine can be started at an early timing to enter the power generation mode, and the engine is started in accordance with the driver's accelerator operation as much as possible. It is possible to suppress the engine starting that does not match the feeling of an accelerator operation.

Next, the effect will be described.
In the control device for the parallel hybrid vehicle of the first embodiment, the effects listed below can be obtained.

(1) According to an electric vehicle traveling mode ("EV mode") having a first clutch CL1 for connecting / disconnecting the engine Eng and the motor (motor / generator MG) and traveling only with the power of the motor (motor / generator MG) When there is an engine start request during traveling, a parallel hybrid vehicle (FR) having engine start control means for connecting the first clutch CL1 and starting the engine Eng using the motor (motor / generator MG) as an engine start motor. In the control device for the hybrid vehicle), the engine start control means (FIG. 2) engages the first clutch CL1 when the target drive torque Td ^* of the vehicle _becomes larger than the cranking request determination threshold value _{Td_th_A.} Eng was cranking and large target driving torque Td ^* is than the cranking request determination threshold T _{D_th_A} after cranking When larger than engine start request determination threshold T _{D_th_B} a have value, starting the engine Eng. For this reason, when there is an engine start request during traveling in the “EV mode”, the number of engine starts can be suppressed.

(2) The engine start control means (FIG. 2) sets the cranking request determination threshold T _{d_th_A} to a value from 0 to the difference between the maximum motor torque and the cranking torque. Therefore, the cranking start timing is the same as in the comparative example, and when the target drive torque Td ^* is large, the drivability is not impaired by promptly shifting to the “HEV mode”. In addition, it is possible to keep the engine loss low without constantly rotating the engine Eng.

(3) The engine start control means (FIG. 2) sets the engine start request determination threshold T _{d_th_B} to a value _larger than the cranking request determination threshold T _{d_th_A} and smaller than the difference between the maximum motor torque and the engine friction torque. . Therefore, the engine start can be completed before reaching the maximum motor torque, and the target drive torque Td ^* can be realized.

(4) The engine start control means (FIG. 2) is _configured to increase the engine start request determination threshold T _{d_th_B} as the accelerator opening change amount ΔApo is smaller, and to approach the difference between the maximum motor torque and the engine friction torque. . Therefore, it is possible to secure the engine start time when the accelerator opening change amount ΔApo is large and to suppress the engine start frequency when the accelerator opening change amount ΔApo is small.

(5) The engine start control means (FIG. 2) sets the engine start request determination threshold T _{d_th_B} to be smaller and closer to the cranking request determination threshold T _{d_th_A} as the battery charge SOC is lower. For this reason, when the battery charge amount SOC is low, it is possible to enter the power generation mode at an early stage, and it is possible to achieve engine start that matches the feeling of accelerator operation.

  As mentioned above, although the control apparatus of the hybrid vehicle of this invention was demonstrated based on Example 1, it is not restricted to this Example 1 about a concrete structure, The invention which concerns on each claim of a claim Design changes and additions are permitted without departing from the gist of the present invention.

  In the first embodiment, a parallel hybrid vehicle having a first clutch that connects / disconnects an engine and a motor / generator and a second clutch that combines power of the engine and at least one motor / generator and transmits the combined power to an output shaft. An applied example is shown. However, the control device of the present invention can be applied to any hybrid vehicle having a first clutch that connects and disconnects the engine and the motor.

1 is an overall system diagram illustrating a parallel hybrid vehicle (an example of a hybrid vehicle) to which a control device according to a first embodiment is applied. 3 is a flowchart showing a flow of hybrid drive integrated control processing including engine start control processing executed by the integrated controller of the first embodiment. It is a figure which shows the target drive torque calculation map used in the integrated control process of Example 1. FIG. It is a detailed flowchart in target driving mode calculation step S6 among the integrated control processing of Example 1. FIG. It is a figure which shows the engine start request | requirement threshold value calculation map used in the integrated control process of Example 1. FIG. It is a detailed flowchart in 1st clutch target control mode calculation step S7 among the integrated control processing of Example 1. FIG. It is a detailed flowchart in target driving mode calculation step S6 among the integrated control processing of Example 1. FIG. It is a figure which shows the gear position command value calculation map used in the integrated control process of Example 1. FIG. It is a detailed flowchart in motor torque command value calculation step S11 among the integrated control processing of Example 1. FIG. It is a calculation map figure used by the integrated control processing of Example 1, (a) shows an example of the map which calculates the target slip rotation speed in HEV mode, (b) shows the target slip rotation speed (increase in cranking). An example of a map for calculating (minute) is shown. It is a detailed flowchart in 2nd clutch torque capacity command value calculating step S11 among the integrated control processing of Example 1. FIG. It is a block diagram which shows the 2nd clutch control system applied in the integrated control process of Example 1. FIG. It is a detailed flowchart in 1st clutch electric current command value calculating step S14 among the integrated control processes of Example 1. FIG. It is a figure which shows the 1st clutch torque capacity-stroke characteristic used in the integrated control process of Example 1. FIG. It is a block diagram which shows the 1st clutch stroke control system applied in the integrated control process of Example 1. FIG. It is a conversion map figure used in the integrated control processing of Example 1, (a) shows an example of the 2nd clutch torque capacity-hydraulic pressure conversion map, (b) shows an example of the 2nd clutch torque oil pressure-current conversion map. Indicates. In the comparative example, accelerator opening, target drive torque, motor speed, CL2 output speed, engine speed, second clutch torque when the mode is changed from "EV mode" to "HEV mode" after engine startup It is a time chart which shows each characteristic of capacity, the 1st clutch torque capacity, motor torque, and engine torque. FIG. 6 is a condition comparison diagram showing a cranking start condition with respect to a target drive torque in a comparative example, a cranking start condition with respect to a target drive torque in Example 1, and an engine start condition. In the first embodiment, the accelerator opening, the target drive torque, the motor speed, the CL2 output speed, the engine speed, the second speed when the mode is changed from the “EV mode” to the “quasi-EV mode” after passing the cranking. It is a time chart which shows each characteristic of clutch torque capacity, 1st clutch torque capacity, motor torque, and engine torque. FIG. 6 is a condition comparison diagram showing a cranking start condition and an engine start condition with respect to a target drive torque at a point 1 in Example 1 and a cranking start condition and an engine start condition with respect to a target drive torque at a point 2 in Example 1; FIG. 6 is a condition comparison diagram showing a cranking start condition and an engine start condition with respect to a target drive torque at a point 1 of Example 1 and a cranking start condition and an engine start condition with respect to a target drive torque at a point 3 of Example 1.

Explanation of symbols

Eng engine
CL1 1st clutch
MG motor / generator (motor)
CL2 2nd clutch
AT automatic transmission
FG final gear
LT Left drive wheel
RT Right drive wheel 6 Second clutch input rotational speed sensor 7 Second clutch output rotational speed sensor 8 High voltage inverter 9 High voltage battery 10 Accelerator position sensor 11 Engine rotational speed sensor 12 Clutch oil temperature sensor 13 Stroke position sensor 14 Integrated controller 15 Transmission controller 16 Clutch controller 17 Engine controller 18 Motor controller 19 Battery controller 20 Brake sensor

Claims (5)

A first clutch for intermittently connecting the engine and the motor;
An engine start control means is provided for connecting the first clutch and starting the engine using the motor as an engine start motor when there is an engine start request during traveling in an electric vehicle traveling mode that travels only with the power of the motor. In a control device for a hybrid vehicle,
The engine start control means independently sets a cranking request determination threshold value and an engine start request determination threshold value that determine the cranking and start timing of the engine,
During traveling in the electric vehicle traveling mode, when the target driving torque of the vehicle becomes larger than the cranking request determination threshold, the first clutch is engaged to crank the engine, and the target driving torque is determined after cranking. in the case it is kept below the a cranking request determination threshold value greater than the engine start request determination threshold, wherein at first clutch is engaged is driven only by the power of the motor without starting the engine Quasi-electric vehicle driving mode,
During driving in the quasi-electric vehicle driving mode, when the target driving torque of the vehicle is equal to or lower than the cranking request determination threshold, the first clutch is released to return to the electric vehicle driving mode,
The hybrid vehicle control device is characterized by starting the engine and shifting to a hybrid vehicle travel mode when a target drive torque of the vehicle becomes larger than the engine start request determination threshold during traveling in the quasi-electric vehicle travel mode. . In the hybrid vehicle control device according to claim 1,
The engine start control means sets the cranking request determination threshold value from 0 to a value equal to or less than a difference between the maximum motor torque and the cranking torque. In the hybrid vehicle control device according to claim 1 or 2,
The engine start control means sets the engine start request determination threshold to a value larger than the cranking request determination threshold and smaller than the difference between the maximum motor torque and the engine friction torque. In the control apparatus of the hybrid vehicle described in any one of Claims 1-3,
The engine start control means is configured to increase the engine start request determination threshold value as the accelerator opening change amount is smaller, and to approach the difference between the maximum motor torque and the engine friction torque. . In the hybrid vehicle control device according to claim 3 or 4,
The control device for a hybrid vehicle, wherein the engine start control means is configured to set the engine start request determination threshold value to be smaller and closer to the cranking request determination threshold value as the battery charge amount is lower.

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