JP5228810B2 - Control device for hybrid vehicle - Google Patents

Description

  The present invention relates to a control device for a hybrid vehicle that has a first clutch that connects and disconnects an engine and a motor generator and limits motor output torque when the temperature of an inverter exceeds an upper limit temperature.

A conventional hybrid vehicle includes an engine and a motor as a drive source, and the engine is connected to an output shaft of the motor via an engine clutch. Moreover, the hybrid vehicle has a starting clutch in its driving system, and the transmission torque to the driving wheels can be varied by the starting clutch. Furthermore, when starting the engine while the motor alone is running, the electronic control unit (ECU) increases the rotation of the motor while slip-controlling the starting clutch, and when the predetermined rotational speed is reached, (For example, refer to Patent Document 1).
JP 2000-255285 A

  However, in the conventional hybrid vehicle control device, when the vehicle stops (hill hold) due to the driver's accelerator operation on an uphill, the motor does not rotate (locks) and generates torque. In order to continue, the temperature of the inverter connected to the motor and performing the DC / AC conversion will rise. Therefore, when the inverter temperature exceeds the upper limit temperature and the motor output torque is limited, the total drive torque transmitted to the drive wheels is reduced by the reduction of the motor output torque, so that the vehicle stop on the uphill road can be maintained. Therefore, there was a problem that the vehicle slipped down (rolled back).

  The present invention has been made paying attention to the above problems, and can control a hybrid vehicle that can maintain a vehicle stop state without rolling back while suppressing an increase in inverter temperature when the vehicle stops on an uphill road. The purpose is to provide.

In order to achieve the above object, in the present invention, the hybrid drive system has a first clutch that connects and disconnects the engine and the motor generator, and limits the motor output torque when the temperature of the inverter connected to the motor generator exceeds the upper limit temperature. The hybrid vehicle control apparatus includes inverter temperature detection means, motor rotation speed detection means, integrated control means, and first clutch torque capacity control means.
The inverter temperature detecting means detects the temperature of the inverter.
The motor rotation speed detection means detects the rotation speed of the motor generator.
The integrated control means determines a target driving torque based on a driver's operation and a vehicle state, distributes the target driving torque to a basic engine torque command value and a basic motor torque command value, and determines the engine based on each torque distribution ratio. And operating points of the motor generator and the first clutch.
The first clutch torque capacity control means includes an inverter upper limit temperature torque calculation unit that calculates an inverter upper limit temperature torque that suppresses a temperature increase of the inverter based on a motor rotation speed detection value and a temperature characteristic of the inverter measured in advance, and an inverter An inverter margin temperature calculation unit that calculates an inverter margin temperature from the temperature detection value to the inverter upper limit temperature, and a first clutch torque capacity that calculates a first clutch torque capacity lower limit value based on a difference between the target drive torque and the inverter upper limit temperature torque comprising a lower limit value calculating portion, and the first clutch torque capacity limit calculator for calculating the first clutch torque capacity limit of the inverter allowance temperature is to lower the high torque, a.
The first clutch torque capacity control means sets a temperature lower than the inverter upper limit temperature as an upper limit set value, and sets the basic engine torque command value as the first clutch torque when the detected temperature value of the inverter is less than the upper limit set value. When it is determined that the detected temperature value of the inverter is equal to or higher than the upper limit set value as the target capacity value, the value limited by the first clutch capacity lower limit value and the first clutch capacity upper limit value is set as the first clutch torque. set as the capacity target value, it performs control for increasing the torque capacity target value to said first clutch.
The integrated control means performs control to decrease the motor torque distribution ratio by an amount corresponding to an increase in the engine torque distribution ratio transmitted from the engine after passing through the first clutch by torque capacity control of the first clutch.

Therefore, in the hybrid vehicle control apparatus of the present invention, when the temperature lower than the inverter upper limit temperature is set as the upper limit set value and the inverter temperature detection value is less than the upper limit set value in the first clutch torque capacity control means. The basic engine torque command value is set as the first clutch torque capacity target value . When it is determined that the temperature detection value of the inverter is equal to or higher than the upper limit set value, a value limited by the first clutch capacity lower limit value and the first clutch capacity upper limit value is set as the first clutch torque capacity target value , Control is performed to increase the torque capacity target value for the first clutch.
In other words, the engine torque distribution ratio is increased by the control for increasing the torque capacity target value for the first clutch as compared to before the temperature condition of the inverter is established. On the other hand, in the integrated control, control is performed so as not to change the target drive torque, so the motor torque distribution ratio decreases as the engine torque distribution ratio increases. Therefore, when the vehicle stops on an uphill road that continues to generate torque while the motor generator is locked, if the inverter temperature rises above the upper limit value, the motor torque distribution ratio that the motor generator is responsible for decreases. Temperature rise is suppressed. Since the upper limit set value, which is a control start condition, is set to a temperature lower than the inverter upper limit temperature, the first clutch torque capacity control is performed prior to the limitation of the motor output torque. For this reason, before and after the start of the first clutch torque capacity control, the balance between the running resistance torque and the driving torque on the uphill road is maintained as it is, and the vehicle stopped state is maintained without rolling back.
As a result, when the vehicle is stopped on the uphill road, the vehicle stopped state can be maintained without rolling back while suppressing an increase in the inverter temperature.

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

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

  As shown in FIG. 1, the drive system of the FR hybrid vehicle in the first embodiment includes an engine Eng, a flywheel FW, a first clutch CL1, a motor generator MG, a second clutch CL2, and an automatic transmission AT. And a propeller shaft PS, a differential DF, a left drive shaft DSL, a right drive shaft DSR, 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 Eng is a lean-burnable engine such as a gasoline engine or a diesel engine. Based on an engine control command from the engine controller 1, the engine Eng uses an intake air amount by a throttle actuator, a fuel injection amount by an injector, and a spark plug. By controlling the ignition timing, the engine torque is controlled to coincide with the command value. The engine output shaft is provided with a flywheel FW.

  The first clutch CL1 is a dry clutch that is interposed between the engine Eng and the motor generator MG and engages / releases between the engine Eng and the motor generator MG. The first clutch CL1 is engaged including the half-clutch state (hydraulic OFF) by the first clutch control hydraulic pressure generated by the first clutch hydraulic unit 6 based on the first clutch control command from the first clutch controller 5.・ Opening (hydraulic ON) is controlled. If the first clutch CL1 is completely engaged, only the motor torque + engine torque is transmitted to the second clutch CL2.

  The motor generator MG is a synchronous motor generator in which a permanent magnet is embedded in a rotor and a stator coil is wound around a stator, and a three-phase AC generated by an inverter 3 is applied based on a control command from the motor controller 2. It is controlled by doing. The motor generator MG can operate as an electric motor that is driven to rotate by receiving power supplied from the battery 4 (hereinafter, this state is referred to as “powering”), and the rotor rotates energy from the engine Eng or the drive wheel. , The battery 4 can be charged by functioning as a generator that generates electromotive force at both ends of the stator coil (hereinafter, this operation state is referred to as “regeneration”). The rotor of the motor generator MG is connected to the transmission input shaft of the automatic transmission AT via a damper.

  The second clutch CL2 is interposed between the motor generator MG and the left and right rear wheels RL and RR, and generates transmission torque to the left and right rear wheels RL and RR, which are drive wheels, according to clutch hydraulic pressure (pressing force). A wet multi-plate brake or a wet multi-plate clutch. The second clutch CL2 is controlled to be engaged and disengaged including slip engagement and slip release by the control hydraulic pressure generated by the second clutch hydraulic unit 8 based on the second clutch control command from the AT controller 7. The first clutch hydraulic unit 6 and the second clutch hydraulic unit 8 are built in an AT hydraulic control valve unit CVU attached to the automatic transmission AT.

  The automatic transmission AT, for example, is a stepped gear that automatically switches stepped gears such as forward 5 speed / reverse 1 speed and forward 7 speed / reverse 1 speed according to the vehicle speed VSP, accelerator opening APO, etc. It is a transmission. The second clutch CL2 is not newly added as a dedicated clutch, but is optimally arranged in the torque transmission path among a plurality of frictional engagement elements that are engaged at each gear stage of the automatic transmission AT. A clutch or brake is selected. Note that the output shaft of the automatic transmission AT is coupled to the left and right rear wheels RL and RR via a propeller shaft PS, a differential DF, a left drive shaft DSL, and a right drive shaft DSR.

  The FR hybrid vehicle of the first embodiment is referred to as an electric vehicle travel mode (hereinafter referred to as “EV mode”) and a hybrid vehicle travel mode (hereinafter referred to as “HEV mode”) according to the engagement / release state of the first clutch CL1. ) Two driving modes. The “EV mode” is a mode in which the first clutch CL1 is released and the vehicle runs 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 is driven by the power of the engine Eng and the motor generator MG.

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

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

  The motor controller 2 inputs information from the resolver 13 that detects the rotor rotational position of the motor generator MG, the target MG torque command and target MG rotation speed command from the integrated controller 10, and other necessary information. Then, a command for controlling the motor operating point (Nm, Tm) of motor generator MG is output to inverter 3 (high voltage inverter). The battery 4 (high voltage battery) connected to the inverter 3 is monitored by a battery controller (not shown) for the battery charge SOC indicating the charge capacity of the battery 4. The information 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 first clutch controller 5 inputs sensor information from the first clutch stroke sensor 15 that detects the stroke position of the piston 14a of the hydraulic actuator 14, a target CL1 torque command from the integrated controller 10, and other necessary information. . Then, a command for controlling engagement / disengagement of the first clutch CL1 is output to the first clutch hydraulic unit 6 in the AT hydraulic control valve unit CVU.

  The AT controller 7 inputs information from an accelerator opening sensor 16, a vehicle speed sensor 17, an inhibitor switch 18, and the like. Then, when driving with the D range selected, a control command for obtaining the searched gear position is searched for the optimum gear position based on the position where the operating point determined by the accelerator opening APO and the vehicle speed VSP exists on the shift map. Output to AT hydraulic control valve unit CVU. The shift map is a map in which an upshift line and a downshift line are written according to the accelerator opening and the vehicle speed. In addition to the above automatic shift control, when a target CL2 torque command is input from the integrated controller 10, a command for controlling the engagement / release of the second clutch CL2 is sent to the second clutch hydraulic unit 8 in the AT hydraulic control valve unit CVU. The second clutch control to output is performed.

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

  The integrated controller 10 manages the energy consumption of the entire vehicle and has a function for running the vehicle with the highest efficiency. A motor rotation speed sensor 21 (motor rotation speed detection means) that detects the motor rotation speed Nm, First clutch temperature sensor 22 (first clutch temperature detection means), second clutch input rotation speed sensor 23 (second clutch input rotation speed detection means), second clutch output rotation speed sensor 24 (second clutch output rotation speed detection) Means), necessary information from the second clutch temperature sensor 25 (second clutch temperature detection means), the inverter temperature sensor 26 (inverter temperature detection means), and the like, and information via the CAN communication line 11. The target engine torque command to the engine controller 1, the target MG torque command and the target MG speed command to the motor controller 2, the target CL1 torque command to the first clutch controller 5, the target CL2 torque command to the AT controller 7, and the brake controller 9 Regenerative cooperative control command is output.

  FIG. 2 is a flowchart showing an integrated control process executed by the integrated controller 10 of the FR hybrid vehicle to which the control device of the first embodiment is applied (integrated control means). Note that the processing content shown in FIG. 2 is executed with constant sampling. Hereinafter, each step will be described.

In step S1, the vehicle state measured by another controller such as the battery charge SOC, the shift position of the transmission, the accelerator opening APO, the vehicle speed VSP, the first clutch stroke x _scl1, etc. is received, and the process proceeds to step S2.

  In step S2, necessary information such as the input / output rotational speed of the first clutch CL1, the input / output rotational speed of the second clutch CL2, the inverter temperature, the first clutch temperature, and the second clutch temperature is measured, and the process proceeds to step S3.

In step S3, a target drive torque Td ^* is calculated from the accelerator opening APO and the vehicle speed VSP. Here, although details of calculation of the target drive torque Td ^* are omitted, for example, the calculation is performed based on a target drive torque calculation map using the accelerator opening APO and the vehicle speed VSP as parameters as shown in FIG. That is, when the vehicle stops on the uphill road, the vehicle speed VSP is zero, but the target drive torque Td ^* is calculated by depressing the accelerator pedal to keep the vehicle stopped.

In step S4, the first clutch control mode flag fCL1 (engagement = engine start / release = engine stop) is set from the vehicle state such as the battery charge amount SOC, the target drive torque Td ^*, and the vehicle speed VSP, and the process proceeds to step S5.
Although the details are omitted here, the first clutch CL1 is released (fCL1 = 0) because, for example, the motor alone (EV mode) travels in a traveling scene where the engine efficiency is relatively poor, such as starting at low acceleration. . In addition, during sudden acceleration, when the battery charge SOC is lower than the upper limit set value SOC _th1 or when the vehicle speed VSP is higher than the upper limit set value VSP _th1 , it is difficult to drive with the “EV mode” selected. The first clutch CL1 is slipped or engaged (fCL1 = 1) in order to shift to the “HEV mode” in which the motor generator MG runs. The slip / fastening determination will be described later.

In step S5, the second clutch control mode CL2MODE (engaged, released, slip) is set from the vehicle state such as the battery charge SOC, the target drive torque Td ^* , the first clutch control mode flag fCL1, and the vehicle speed VSP, and the process proceeds to step S6. move on. Details will be described later.

In step S6, the target drive torque Td ^* calculated in step S3 is changed to the basic engine torque command value _{Te_base} ^* and the basic motor torque command value _{Tm_base} ^* based on the control mode and vehicle state of each clutch CL1, CL2. Allocate and proceed to step S7.
Various methods can be considered for the distribution method, but the details are omitted.

In step S7, the torque capacity target value T _cl1 ^* of each of the clutches CL1 and CL2 during rotation speed control, which will be described later, from the inverter temperature T _{emp_INV} , each clutch temperature T _{emp_cl1} , T _{emp_cl2} and the second clutch output rotation speed measured value ω _cl2o , T _cl2 ^* , input rotation speed target values ω _cl1i ^* , ω _{cl2 i} ^* are calculated, and the process proceeds to step S8. Detailed description will be given later.

In step S8, it is determined whether or not the slip rotation speed control of the first clutch CL1 is to be executed. The first clutch control mode state determined in step S4 is set to slip or engagement, and the input shaft speed target values ω _cl1i ^* and ω _cl2i ^* of the first clutch CL1 and the second clutch CL2 calculated in step S7 are set. If the absolute value of the actual slip rotation speed (input shaft-output shaft) is not less than the specified value, the slip rotation speed control is turned ON and the operation proceeds to step S9. Otherwise, the slip rotation speed control is turned OFF. To step S11.

In step S9, following the determination that the first clutch slip rotation speed control is ON in step S8, the first clutch input rotation speed target value ω _cl1i ^* and the first clutch input rotation speed measurement value ω _cl1i are matched. The engine torque command value _{Te_FB_ON} for number control is calculated, and the process proceeds to step S10.
Here, various calculation (control) methods can be considered. For example, calculation is performed based on the following formula (PI control). The actual calculation is calculated using a recurrence formula obtained by discretization by Tustin approximation or the like. The arithmetic expression is
T _{e_FB_ON} = {(K _Pe · s + K _Ie ) / s} {ω _cl1i ^* −ω _cl1i } (1)
And
However,
K _Pe : Proportional gain for engine control
K _Ie : integral gain for engine control s: differential operator

In step S10, a first clutch torque capacity command value _{Tcl1_FB_ON} for rotational speed control is calculated, and the process proceeds to step S13.
Basically, it is set to the same value as the first clutch torque capacity target value _Tcl1 ^* calculated in step S7. Further, correction may be performed by an F / B compensator configured in the same manner as in step S9.

In step S11, following the determination that the first clutch slip rotational speed control is OFF in step S8, the internal state variable for calculating the engine torque command value _{Te_FB_ON} for rotational speed control described above is initialized, and the process _proceeds to step S12. move on.

In step S12, when the first clutch slip rotational speed control is not performed, that is, the clutch torque capacity command value until the first clutch CL1 is engaged / released or from the engaged state to the slip rotational speed control (slip state). _{Tcl1_FB_OFF} is calculated, and the process proceeds to step S13. The arithmetic expression is
1) When fastening
1-1) If T _{cl1_z1} ^* <T _e ^* × K _safe
T _{cl1_FB_OFF} = T _{cl1_z1} ^* + ΔT _cl1LU (2)
1-2) If T _{cl1_z1} ^* ≧ T _e ^* × K _safe
T _{cl1_FB_OFF} = T _e ^* × K _safe (3)
2) When opening
T _{cl1_FB_OFF} = 0 (4)
3) When fastening → slipping
T _{cl1_FB_OFF} = T _{cl1_z1} ^* −ΔT _cl1slp (5)
And
However,
K _safe : Clutch safety factor (> 1)
ΔT _cl1LU : Slip (or release) → torque capacity change rate at the transition to fastening ΔT _cl1slp : Torque capacity change rate at the time of fastening → slip transition
T _{cl1_z1} ^* : The last value of the final first torque command value.

  In step S13, it is determined whether or not the slip rotation speed control of the second clutch CL2 is to be executed. If the second clutch control mode state determined in step S5 is set to slip, and the actual slip rotation speed (input shaft-output shaft) absolute value exceeds a predetermined value, the slip rotation speed control is turned ON. If it is set to release or engagement in step S14, the slip rotation speed control is turned OFF and the process proceeds to step S16.

In step S14, following the determination that the second clutch slip rotational speed control is ON in step S13, the second clutch input rotational speed target value ω _cl2i ^* and the second clutch input rotational speed measured value ω _cl2i are matched. The number control motor torque command value T _{m_FB_ON} is calculated, and the process proceeds to step S15.
Here, various calculation (control) methods are conceivable. For example, similar to step S9, calculation is performed based on the following equation (PI control). The actual calculation is calculated using a recurrence formula obtained by discretization by Tustin approximation or the like. The calculation formula is
T _{m_FB_ON} = {(K _Pm · s + K _Im ) / s} {ω _cl2i ^* −ω _cl2i } (6)
And
However,
K _Pm : Proportional gain for motor control
K _Im : integral gain for motor control.

In step S15, the second clutch torque capacity command value _{Tcl2_FB_ON} for controlling the rotational speed is calculated, and the process proceeds to step S18.
Basically, it is set to the same value as the second clutch torque capacity target value T _cl2 ^* calculated in step S7. Further, as with the first clutch, correction may be performed by an F / B compensator.

In step S16, following the determination of the second clutch slip rotation speed control OFF in step S13, the internal state variable for calculating the motor torque command value T _{m_FB_ON} for rotation speed control described above is initialized, and the process _proceeds to step S17. move on.

In step S17, when the second clutch slip rotational speed control is not performed, that is, the clutch torque capacity command value T until the second clutch CL2 is engaged / released or engaged from the engaged state to the rotational speed control (slip state). _{Calculate cl2_FB_OFF} and proceed to step S18. The arithmetic expression is
4) When fastening
1-1) If T _{cl2_z1} ^* <T _d ^* × K _safe
T _{cl2_FB_OFF} = T _{cl2_z1} ^* + ΔT _cl2LU (7)
1-2) If T _{cl2_z1} ^* ≧ T _d ^* × K _safe
T _{cl2_FB_OFF} = T _d ^* × K _safe (8)
5) When opening
T _{cl2_FB_OFF} = 0 (9)
6) When fastening → slipping
T _{cl2_FB_OFF} = T _{cl2_z1} ^* −ΔT _cl2slp (10)
And
However,
ΔT _cl2LU : Slip (or release) → Torque capacity change rate at the time of fastening transition ΔT _cl2slp : Torque capacity change rate at the time of fastening → slip transition
T _{cl2_z1} ^* : Last value of the last second torque command value.

In step S18, a final first clutch torque capacity command value _Tcl1 ^* is determined based on the following conditions, and the process proceeds to step S19. The determinant is
1) When the first clutch CL1 is under rotation speed control
^{_{T cl1 * = T cl1_FB_ON (11}} )
2) When the first clutch CL1 is stopped
^{_{T cl1 * = T cl1_FB_OFF (12}} )
And

In step S19, a final second clutch torque capacity command value _Tcl2 ^* is determined based on the following conditions, and the process proceeds to step S20. The determinant is
1) When the second clutch CL2 is under rotation speed control
T _cl2 ^* = T _{cl2_FB_ON} (13)
2) When the second clutch CL2 is stopped
T _cl2 ^* = T _{cl2_FB_OFF} (14)
And

In step S20, a current command value I _cl1 ^* to the solenoid valve for controlling the hydraulic pressure applied to the first clutch CL1 is calculated from the first clutch torque capacity command value T _cl1 ^*, and the process proceeds to step S21. A detailed calculation method will be described later.

In step S21, a current command value I _cl2 ^* to the solenoid valve that controls the hydraulic pressure applied to the second clutch CL2 is _calculated from the second clutch torque capacity command value T _cl2 ^* . Actually, it is calculated using a second clutch torque capacity-hydraulic pressure conversion map shown in FIG. 4 and a clutch torque hydraulic pressure-current conversion map shown in FIG. 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 S22, final motor torque command value Tm ^* is determined based on the following conditions, and the process proceeds to step S23. The determinant is
1) When the second clutch CL2 is under rotation speed control
Tm ^* = T _{m_FB_ON} (15)
2) When the second clutch CL2 is stopped
Tm ^* = T _{m_base} ^* (16)
And

In step S23, final engine torque command value Te ^* is determined based on the following conditions, and the process proceeds to step S24. The determinant is
1) When 1st clutch CL1 is under rotation speed control
Te ^* = _{Te_FB_ON} (17)
2) When the first clutch CL1 is stopped
Te ^* = _{Te_base} ^* (18)
And

  In step S24, the calculated command value is transmitted to each control controller 1, 2, 5, 7, 9.

  FIG. 6 is a flowchart showing a setting process (step S5 in FIG. 2) of the second clutch control mode CL2MODE executed by the integrated controller 10 of the FR hybrid vehicle to which the control device of the first embodiment is applied. The second clutch control mode CL2MODE is set from the vehicle state such as the battery charge amount SOC, the target drive torque Td *, the first clutch control mode flag fCL1, and the vehicle speed VSP. Hereinafter, each step of the flowchart shown in FIG. 6 will be described.

  In step S51, the first clutch control mode flag fCL1 is determined. If the first clutch control mode flag fCL1 is engaged (engine start) (fCL1 = 1), the process proceeds to step S55, and if it is the release mode (engine stop) (fCL1 = 0), the process proceeds to step S52.

  In step S52, following the determination that the first clutch control mode flag fCL1 is the disengagement mode in step S51, it is determined whether or not the vehicle speed VSP is zero (stopped). If it is stopped (VSP = 0), the process proceeds to step S53. Otherwise, the process proceeds to step S54.

  In step S53, following the determination that the vehicle speed VSP is zero (stopped) in step S52, the second clutch control mode is set to the engagement mode (CL2MODE = 1) and the process proceeds to the end.

  In step S54, following the determination that the vehicle speed VSP is not zero in step S52, the second clutch control mode is set to the slip mode (CL2MODE = 2), and the process proceeds to the end.

  In step S55, following the determination that the first clutch control mode flag fCL1 is the engagement mode in step S51, it is determined whether or not the vehicle speed VSP is higher than a predetermined value Vth1 (for example, the lowest vehicle speed at which the engine can be started). . If it is low, the process proceeds to step S56, and if it is high, the process proceeds to step S58.

In step S56, following the determination that the vehicle speed VSP is lower than the predetermined value Vth1 in step S55, the sign of the target drive torque Td ^* is determined. If the value is positive, the process proceeds to step S54. If the value is negative, the process proceeds to step S54. Proceed to S57.

In step S57, following the determination that the sign of the target drive torque Td ^* in step S56 is a negative value, the second clutch control mode is set to the disengagement mode (CL2MODE = 0), and the process proceeds to the end.

  In step S58, following the determination that the vehicle speed VSP in step S55 is greater than or equal to the predetermined value Vth1, it is determined whether or not the previous second clutch control mode CL2MODE_z1 is the engagement mode. In the case of the fastening mode (CL2MODE_z1 = 1), the process proceeds to step S53, and in other cases (CL2MODE_z1 = 0), the process proceeds to step S59.

In step S59, following the determination that the previous second clutch control mode CL2MODE_z1 is not the engagement mode in step S58, the engine speed measurement value ω _e , the second clutch slip rotation speed measurement value ω _cl2slp , and the slip rotation speed are calculated. From the threshold value _ωcl2slpth , when the following condition is satisfied, the process proceeds to step S54, where slip is started or continued. When the condition is not satisfied, the process proceeds to step S53, where the slip is terminated and a transition is made to the engagement mode. The slip continuation condition is
ω _e ≠ ω _cl2i (CL1 open or slip), or ω _cl2slp > ω _cl2slpth
And

Next, a method of calculating the first clutch torque capacity target value T _CL1 ^* and the second clutch torque capacity target value T _CL2 ^* during the slip rotation speed control will be described. As shown in FIG. 1, the second clutch CL2 transmits the combined torque of the motor generator MG and the engine Eng, that is, the driving torque, so that the torque capacity target value is the above-described target driving torque Td ^* .

FIG. 7 is a flowchart showing a calculation process (step S7 in FIG. 2) of the first clutch torque capacity target value T _CL1 ^* executed by the integrated controller 10 of the FR hybrid vehicle to which the control device of the first embodiment is applied. Yes (first clutch torque capacity control means). Hereinafter, each step will be described.

In step S711, calculates the difference (margin _temperature) T emp_mag_INV from the inverter temperature measurement value T _{Emp_INV} to inverter upper limit temperature, the process proceeds to step S712.

In step S712, calculates the difference (margin _temperature) T emp_mag_cl1 from the first clutch temperature measurement value T _{Emp_cl1} to the upper limit temperature of the first clutch CL1, the process proceeds to step S713.

In step S713, when the previous time is less than the upper limit set value _{Temp_INV_maxth} and the inverter temperature measured value _{Temp_INV} is increasing, it is determined whether the inverter temperature measured value _{Temp_INV} is greater than or equal to the upper limit set value _{Temp_INV_maxth} . To step S714 in the case of more than the upper limit set value _T emp_INV_maxth, if it is less than the upper limit set value T _{Emp_INV_maxth} proceeds to step S718.
Further, when the previous time exceeds the lower limit set value _{Temp_INV_minth} and the inverter temperature measured value _{Temp_INV} is decreasing, it is determined whether the inverter temperature measured value _{Temp_INV} is equal to or lower than the lower limit set value _{Temp_INV_minth} . If the lower limit set value _{Temp_INV_minth is} less than or equal to step S718, the process proceeds to step S718. If the lower limit set value _{Temp_INV_minth} is exceeded, the process proceeds to step S714.
Here, the upper limit set value _{Temp_INV_maxth} is set to a temperature lower than the inverter upper limit temperature, and a _margin is provided with _respect to the upper limit temperature, so that even when the target drive torque Td ^* further increases, it is possible to cope with it. Further, the lower limit set value _{Temp_INV_minth} is set to a temperature lower than the upper limit set value _{Temp_INV_maxth} to ensure an inverter temperature suppression time.

In step S714, _until the inverter temperature measurement value _{Temp_INV} in step S713 is determined to be _{equal to} or higher than the upper limit setting value _{Temp_INV_maxth} until it is determined to be equal to or lower than the lower limit setting value _{Temp_INV_minth} , Motor) Rotational speed measurement value ω _cl2i is input, inverter upper limit temperature torque T _{INV_MAX} is calculated from the temperature characteristics of the inverter measured in advance (FIG. 8), and the process proceeds to step S715.

In step S715, the first clutch torque capacity lower limit T _{CL1_MIN} is calculated from the target drive torque Td ^* and the inverter upper limit temperature torque T _{INV_MAX} , and the process proceeds to step S716. The arithmetic expression is
T _{CL1_MIN} = Td ^* −T _{INV_MAX}
It is.
However, the lower limit of the first clutch torque capacity lower limit value _{TCL1_MIN} is zero.

In step S716, the first clutch torque capacity upper limit value _{TCL1_MAX} is calculated from the inverter margin temperature _{Temp_mag_INV} using the first clutch torque capacity upper limit value calculation map shown in FIG. 9, and the process proceeds to step S717.

In step S717, the first clutch torque capacity target value T _CL1 ^* is calculated from the first clutch margin temperature _{Temp_mag_cl1,} and the process proceeds to the end. Actually, the calculation is performed based on the first clutch torque capacity target value calculation map limited by the upper and lower limits of the first clutch torque capacity as shown in FIG.

In step S718, it is determined that the inverter temperature measurement value _{Temp_INV} in step S713 is less than the upper limit setting value _{Temp_INV_maxth} (start condition is not satisfied), or the inverter temperature measurement value _{Temp_INV} is _{equal to} or greater than the lower limit setting value _{Temp_INV_minth Next} , the first clutch torque capacity upper limit value T _{CL1_MAX} is _set to the basic engine torque command value _{Te_base} ^* and the lower limit value is set to 0, and the first clutch torque capacity target value T is determined in the same manner as in step S717. Calculate _CL1 ^* and go to the end.

Next, details of a calculation method of the first clutch input rotation speed target value ω _cl1i ^* and the second clutch input rotation speed target value ω _cl2i ^* will be described.
First, a method for setting the first clutch input rotational speed target value ω _cl1i ^* will be described.
Since the input side of the first clutch CL1 is directly connected to the engine Eng as shown in FIG. 1, it is necessary to set at least a rotation speed at which the engine Eng does not stall, and the lower differential rotation is the first. The amount of heat generated by one clutch CL1 is reduced. Accordingly, the first clutch input rotational speed target value ω _cl1i ^* is set to the higher one of the minimum rotational speed ω _{e — MIN at} which the engine Eng does not stall and the second clutch input rotational speed measured value ω _cl2i .

FIG. 11 is a flowchart showing a calculation process (step S7 in FIG. 2) of the second clutch input rotation speed target value ω _cl2i ^* , which is executed by the integrated controller 10 of the FR hybrid vehicle to which the control device of the first embodiment is applied. (Second clutch input rotation speed control means). Hereinafter, each step of the flowchart will be described.

In step S721, differences (margin temperatures) T _{emp_mag_cl1} and T _{emp_mag_cl2} from the first and second clutch temperature measured values T _{emp_cl} and T _{emp_cl2} to the upper limit temperatures of the clutches CL1 and CL2 are calculated, and the process proceeds to step S722.

In step S722, the first clutch input shaft rotational speed measured value ω _cl1i is set as the upper limit value, the second clutch output shaft rotational speed measured value ω _cl2o is set as the lower limit value, and the basic second clutch input rotational speed target value ω _{cl2i_base} ^* is calculated. The process proceeds to step S723. Actually, the calculation is performed based on the basic second clutch input rotational speed target value calculation map shown in FIG. 12 from the deviation ΔT _{emp_mag_cl} (= T _{emp_mag_cl2} −T _{emp_mag_cl1} ) of each clutch margin temperature.

In step S723, calculates the difference (margin _temperature) T emp_mag_INV from the inverter temperature measurement value T _{Emp_INV} to the upper limit temperature, the process proceeds to step S724.

In step S724, when the inverter margin temperature _{Temp_mag_INV} is zero, the second clutch input rotational speed target value ω _cl2i ^* is equal to or higher than the unlocked rotational speed ω _{UN_LOCK} (a value at which the inverter temperature does not increase even if the rotational speed is increased further). The correction is made so that Actually, the final second clutch input rotational speed target value ω _cl2i ^* is calculated based on the following conditions. The arithmetic expression is
1) ω _{cl2i_base} ^* ≧ ω _{UN_LOCK}
ω _cl2i ^* = ω _{cl2i_base} ^*
2) ω _{cl2i_base} ^* <ω _{UN_LOCK}
ω _cl2i ^* = ω _{cl2i_base} ^* + ω _{cl2i_HOSEI}
And
However, ω _{cl2i_HOSEI} is a second clutch input rotation speed correction value, and is calculated based on, for example, a second clutch input rotation speed correction value map shown in FIG.

Next, a calculation method of the solenoid valve current command value I _cl1 ^* for controlling the hydraulic pressure of the first clutch CL1 will be described. FIG. 14 is a flowchart showing a first clutch current command value calculation process (step S20 in FIG. 2) executed by the integrated controller 10 of the FR hybrid vehicle to which the control device of the first embodiment is applied. Hereinafter, each step will be described.

In step S161, the first clutch torque capacity command value T _cl1 ^*, previously acquired first clutch torque capacity - using the map created (FIG. 15) by the stroke characteristic, calculates a first clutch stroke command value x _SCL1 ^* Then, the process proceeds to step S162.

In step S162, from the first clutch stroke command value x _SCL1 ^* and the stroke measured value, calculated based on the following a hydraulic pressure command value P _cl1 ^*, the process proceeds to step S163. In the first embodiment, a two-degree-of-freedom control method is adopted as in the above-described second clutch rotational speed control (FIG. 16).

First, from the first clutch stroke command value x _scl1 ^* , an F / F using a phase compensation filter consisting of the inverse system of the reference response transmission characteristic as shown in the following equation and the control target transmission characteristic after hydraulic pressure correction described later is used. _Calculate hydraulic pressure command value _{Pcl1_FF} . The arithmetic expression is
(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} }
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} )
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
It becomes.
However,
K _{Pgain_cl1} : Proportional gain
K _{Igain_cl1} : Integral gain
K _{Dgain_cl1} : Differential gain. Finally, by adding the F / F hydraulic pressure command value P _{Cl1_FF} and F / B pressure command value P _{Cl1_FB,} the hydraulic pressure command value P _cl1 ^*.

  In step S163, the hydraulic pressure command value is corrected so that the slope 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.

First, as shown in the upper part of FIG. 17, each stroke (operating point) and the origin are connected by a straight line. Then, as shown in the lower part of FIG. 17, the slope of each straight line is modeled (mapped) as a spring constant.
Thus to the spring constant and norms spring constant K _ref of the control target K _p obtained in calculates the final hydraulic pressure command value P _{Cl1_com} based on the following equation, the process proceeds to step S164. The arithmetic expression is
P _{cl1_com} = (K _p / K _ref ) ・ P _cl1 ^*
It becomes.

In step S164, the current command value I _cl1 ^* is calculated from the final hydraulic pressure command value P _{cl1_com} using a map (see FIG. 5) created based on the previously acquired characteristics, as with the second clutch CL2.

Next, the operation will be described.
First, “problem in comparative example control at the time of hill hold” will be described, and then the operation in the control device for the FR hybrid vehicle of the first embodiment will be described as “integrated control during slip rotation speed control of both clutches”. The description will be divided into “target value calculation operation”, “inverter overheat suppression control operation during hill hold”, and “overheat suppression control operation of the inverter and the first clutch during hill hold”.

[Problems with comparative example control during hill hold]
FIG. 18 is a time chart showing an example of a simulation result of the rotational speed, clutch torque capacity, engine / motor torque, driving torque, and temperature in the comparative example control during hill hold. In this simulation, a stop state is maintained (hill hold) by matching the driving torque with the running resistance by the driver's accelerator operation from 1.0 [sec] in the gradient where the running resistance of 100 Nm is generated.

  The comparative example has a first clutch and a second clutch between the engine and the motor generator, and between the motor generator and the transmission, respectively, and controls the clutch according to each traveling condition ( This is a system that switches between HEV mode and EV mode. In this comparative example, the fuel efficiency is improved by starting in the “EV mode” in which only the motor generator is used as the power source, particularly under conditions where the engine efficiency is low such as starting.

  However, in the comparative example, as shown in FIG. 18, when the state such as the vehicle stop (hill hold) by the driver's accelerator operation continues on the uphill road, the motor generator generates torque in a non-rotating (locked) state. In order to continue, there was a problem that the output torque was limited by the rise of the inverter temperature, and the vehicle slipped (rollback) and the engine could not be started.

  Incidentally, as shown in the temperature characteristics of FIG. 18, when the inverter reaches the upper limit temperature about 2.5 [sec] after the vehicle stops on the uphill road, the engine / motor torque characteristics and the drive torque characteristics of FIG. In addition, the motor torque is limited from the time when the inverter temperature reaches the upper limit temperature, and the drive torque (output torque) decreases with this limitation. When the driving torque decreases, the running resistance torque received from the uphill road exceeds the driving torque, and as shown in the rotational speed characteristics of FIG. 18, the vehicle cannot hold the stopped state, and the vehicle slips due to the reverse vehicle speed. A fall (rollback) occurs.

[Target value calculation by integrated control during slip rotation speed control of both clutches]
The target value calculation operation by the integrated control during the slip rotation speed control of both clutches CL1 and CL2 will be described based on the flowchart of FIG.

  When the first clutch CL1 and the second clutch CL2 are under slip rotational speed control, in the flowchart of FIG. 2, step S1, step S2, step S3, step S4, step S5, step S6, step S7, step S8, step S9 → Step S10 → Step S13 → Step S14 → Step S15 → Step S18 → Step S19 → Step S20 → Step S21 → Step S22 → Step S23 → Step S24

That is, in step S6, the target drive torque Td ^* calculated based on the accelerator opening APO and the vehicle speed VSP is distributed to the basic engine torque command value _{Te_base} ^* and the basic motor torque command value _{Tm_base} ^* . In step S7, from the inverter temperature T _{emp_INV} , the first clutch temperature T _{emp_cl1} , the second clutch temperature T _{emp_cl2,} and the second clutch output rotation speed measured value ω _cl2o , the first clutch torque capacity target value during the slip rotation speed control. and T _cl1 ^*, the second clutch torque capacity target value T _cl2 ^*, a first clutch input rotational speed target value _ω cl1i ^*, the second clutch input rotational speed target value _ω cl2i ^* is calculated. In step S9, the engine torque command value _{Te_FB_ON} is calculated. In step S10, the first clutch torque capacity command value _{Tcl1_FB_ON} for controlling the rotational speed (basically the first clutch torque capacity target value calculated in step S7). Equivalent to T _cl1 ^* ). In step S14, a motor torque command value T _{m_FB_ON} for rotation speed control is calculated. In step S15, the second clutch torque capacity command value T _{cl2_FB_ON} for rotation speed control (basically the second torque calculated in step S7). Clutch torque capacity target value T _cl2 ^* ) is calculated.

As described above, each target value is
· First clutch torque capacity target value T _cl1 ^*: Flowchart second clutch torque capacity target value shown in FIG. ^{_{7 T cl2 *: T cl2 *}} = Td * ( the target driving torque)
・ First clutch input rotational speed target value ω _cl1i ^* : The _{higher of the} minimum rotational speed ω _{e_MIN} and the second clutch input rotational speed measured value ω _cl2i at which the engine Eng does not stall ・ The second clutch input rotational speed target value ω _cl2i ^* : Flowchart shown in FIG. 11-Engine torque command value _{Te_FB_ON} : Value at which the first clutch input rotational speed target value _ωcl1i ^* matches the first clutch input rotational speed measured value _ωcl1i -Motor torque command value _{Tm_FB_ON} : Second The clutch input rotational speed target value ω _cl2i ^* and the second clutch input rotational speed measured value ω _cl2i are calculated based on a matching value.

[Inverter overheat suppression control action during hill hold]
FIG. 19 is a time chart showing an example of a simulation result of the rotational speed, clutch torque capacity, engine / motor torque, driving torque, and temperature in the inverter overheat suppression control in the first embodiment during hill hold. Similar to the comparative example, this simulation maintains the stop state by matching the driving torque and the running resistance by the driver's accelerator operation from 1.0 [sec] in the slope where the running resistance of 100 Nm is generated (hill hold) I am trying to let you.

For example, when the temperature of the inverter 3 is stable at a low temperature and the inverter temperature measurement value _{Temp_INV} is less than the upper limit setting value _{Temp_INV_maxth} , in the flowchart of FIG. 7, go to step S711 → step S712 → step S713 → step S718. The flow going forward is repeated.
That is, in step S711, the difference from the inverter temperature measurement value T _{Emp_INV} to inverter upper limit temperature (room _temperature) T emp_mag_INV is calculated, in step S712, the first clutch temperature measurement value T _{Emp_cl1} to the upper limit temperature of the first clutch CL1 Difference (margin temperature) _{Temp_mag_cl1} is calculated. Then, based on the determination that the inverter temperature measurement value T _{Emp_INV} in step S713 is less than the upper limit set value T _{Emp_INV_th,} in step S718, the first clutch torque capacity limit T _{CL1_MAX} the basic engine torque command value _T e_base ^* The first clutch torque capacity lower limit T _{CL1_MIN} is _set to 0, and the first clutch torque capacity target value T _CL1 ^* is calculated from the first clutch margin temperature _{Temp_mag_cl1} .

For example, when the temperature of the inverter 3 rises when the vehicle stops on an uphill road, and the inverter temperature measurement value _{Temp_INV} becomes a temperature _{equal to} or higher than the upper limit set value _{Temp_INV_maxth} , in the flowchart of FIG. 7, step S711 → step S712 → The process proceeds from step S713 to step S714 to step S715 to step S716 to step S717. Then, even if the inverter temperature measurement value _{Temp_INV} decreases, until it is determined that the lower limit set value _{Temp_INV_minth is not} more than the lower limit set value _{Temp_INV_minth} , in the flowchart of FIG. 7, step S711 → step S712 → step S713 → step S714 → step S715 → step S716 → The flow of proceeding to step S717 is repeated.

That is, _until it is determined that the inverter temperature measurement value _{Temp_INV} in step S713 is _{equal to} or higher than the upper limit setting value _{Temp_INV_th until} it is determined that the inverter temperature measurement value _{Temp_INV_th} is lower than the lower limit setting value _{Temp_INV_minth} , Using the clutch input shaft (motor) rotational speed measurement value ω _cl2i as an input, the inverter upper limit temperature torque T _{INV_MAX} is calculated from the temperature characteristics of the inverter measured in advance (FIG. 8). In step S715, the first clutch torque capacity lower limit value _{TCL1_MIN} is calculated from the target drive torque Td ^* and the inverter upper limit temperature torque _{TINV_MAX} . In step S716, the first clutch torque capacity upper limit value _{TCL1_MAX} is calculated from the inverter margin temperature _{Temp_mag_INV} using the first clutch torque capacity upper limit value calculation map shown in FIG. In step S717, the first clutch torque capacity target value T _CL1 ^* limited by the first clutch torque capacity upper and lower limit values T _{CL1_MIN} and T _{CL1_MAX} is calculated from the first clutch margin temperature _{Temp_mag_cl1} (FIG. 10). .

As described above, in the first embodiment, when the temperature condition that the temperature lower than the inverter upper limit temperature is the upper limit set value _{Temp_INV_th} and the inverter temperature measurement value _{Temp_INV of} the inverter 3 is _{equal to} or higher than the upper limit set value _{Temp_INV_maxth} is satisfied. Control for increasing the first clutch torque capacity target value T _CL1 ^* for the first clutch CL1 is performed. By performing the increase control of the first clutch torque capacity, the engine torque distribution ratio transmitted from the engine Eng through the first clutch CL1 is increased compared to before the temperature condition of the inverter 3 is established. On the other hand, in the integrated control, control is performed so as not to change the target drive torque Td ^*. Therefore, the motor torque distribution ratio decreases as the engine torque distribution ratio increases.

Therefore, when the vehicle stops on an uphill road where the motor generator MG continues to generate torque while the motor generator MG is locked, if the inverter temperature rises above the upper limit set value _{Temp_INV_maxth} , the motor torque distribution ratio that the motor generator MG is responsible for decreases. Therefore, the temperature rise of the inverter 3 is suppressed. Since the upper limit set value _{Temp_INV_maxth} is lower than the inverter upper limit temperature, the first clutch torque capacity control for suppressing overheating of the inverter 3 is performed prior to the limitation of the motor output torque. For this reason, before and after the start of the first clutch torque capacity control, the balance between the running resistance torque and the driving torque on the uphill road is maintained as it is, and the vehicle stopped state is maintained without rolling back.

In Example 1, the temperature lower than the upper limit set value T _{Emp_INV_maxth} the lower limit set value T _{Emp_INV_minth,} inverter temperature measurement value T _{Emp_INV} inverter 3 is lower by increasing the torque capacity target value of the first clutch CL1 When it is determined that the set value _{Temp_INV_minth} or less, control is performed to decrease the target torque capacity value for the first clutch CL1. Since the return control for returning the increased first clutch torque capacity to the original is performed, the first clutch temperature that has increased due to the increase in the torque capacity of the first clutch CL1 decreases, and the torque capacity decreases due to the return control. The temperature of the clutch CL1 can be lowered, and the deterioration of the first clutch CL1 is prevented.

  The above operation will be described with reference to the flowchart shown in FIG. 19. When the inverter temperature reaches or exceeds the upper limit set value when the elapsed time from the vehicle stop on the uphill road reaches 3.0 [sec], the first clutch torque capacity is increased. By doing so, the distribution to the motor torque decreases, and as a result, the inverter temperature decreases. As a result, the output of motor generator MG is not limited, and the vehicle stop state can be maintained without rolling back.

  Also, when the temperature of the first clutch CL1 rises due to the increase in the torque capacity of the first clutch CL1, and the inverter temperature reaches the lower limit set value when the elapsed time from the vehicle stop is around 5.0 [sec], the torque capacity decreases this time. Therefore, the temperature of the first clutch CL1 can be lowered, and the deterioration of the first clutch CL1 can be prevented.

  Further, when the inverter temperature reaches the upper limit set value or more again in the vicinity where the elapsed time from the vehicle stop on the uphill road becomes 7.0 [sec], the motor torque is increased by increasing the first clutch torque capacity as described above. Allocation to decreases. Further, when the inverter temperature reaches the lower limit set value when the elapsed time from the vehicle stop is around 9.0 [sec], the torque capacity decreases this time as described above.

[Overheat suppression control action of inverter and first clutch during hill hold]
FIG. 20 is a time chart showing an example of a simulation result of the rotation speed, clutch torque capacity, engine / motor torque, driving torque, and temperature in the overheat suppression control of the inverter 3 and the first clutch CL1 in the first embodiment at the time of hill hold. It is a chart. Similar to the comparative example, this simulation maintains the stop state by matching the driving torque and the running resistance by the driver's accelerator operation from 1.0 [sec] in the slope where the running resistance of 100 Nm is generated (hill hold) I am trying to let you.

  For example, when the vehicle stops on an uphill road, the increase control of the first clutch torque capacity is executed, so that the temperature of the inverter 3 has a marginal temperature with respect to the inverter upper limit temperature. However, when the temperature of the first clutch CL1 rises due to the increase in torque capacity and the margin becomes smaller than the first clutch upper limit temperature, the second clutch CL2 has margin for the second clutch upper limit temperature. On the condition, in the flowchart of FIG. 11, the flow from step S721 → step S722 → step S723 → step S724 is repeated.

That is, in step S721, differences (margin temperatures) T _{emp_mag_cl1} and T _{emp_mag_cl2} from the first and second clutch temperature measured values T _{emp_cl} and T _{emp_cl2} to the upper limit temperatures of the clutches CL1 and CL2 are calculated. In step S722, the first clutch input shaft rotational speed measurement value ω _cl1i is the upper limit value, the second clutch output shaft rotational speed measurement value ω _cl2o is the lower limit value, and each clutch margin temperature deviation ΔT _{emp_mag_cl} (= T _{emp_mag_cl2} −T _{emp_mag_cl1} ), The basic second clutch input rotational speed target value ω _{cl2i_base} ^* is calculated. In step S723, the difference from the inverter temperature measurement value T _{Emp_INV} to the upper limit temperature (room _temperature) T emp_mag_INV is calculated. In step S724, when the inverter margin temperature _{Temp_mag_INV} is zero, the second clutch input rotational speed target value ω _cl2i ^* is the non-locking rotational speed ω _{UN_LOCK} (a value at which the inverter temperature does not increase even if the rotational speed is further increased). Correction is performed so as to be the above.

As described above, in the first embodiment, the first _generator input shaft rotational speed measurement value ω _cl1i is the upper limit value, and the second clutch output shaft rotational speed measurement value ω _cl2o is the lower limit value. Then, control is performed to increase the second clutch input rotational speed target value ω _cl2i ^* for the second clutch CL2. By the control for increasing the second clutch input rotation speed, the differential rotation (slip rotation speed) of the first clutch CL1 is reduced, and the temperature of the first clutch CL1 can be lowered. In other words, by controlling both the torque capacity of the first clutch CL1 and the slip rotational speed, the inverter temperature (heat generation amount) and the first clutch temperature (heat generation amount) are compared with only the torque capacity control of the first clutch CL1. Can be set freely. Therefore, for example, even when the temperature of both the inverter 3 and the first clutch CL1 rises, the slip of the first clutch L1 is controlled by the rotational speed control of the motor generator MG while the motor torque is reduced by the increase control of the first clutch torque capacity. By reducing the rotational speed, the inverter temperature and the first clutch temperature can be lowered simultaneously.

  The above operation will be described with reference to the flowchart shown in FIG. 20. When the first clutch temperature rises while the inverter temperature is being lowered, in the vicinity where the elapsed time from the vehicle stop on the uphill road becomes 8.0 [sec]. Reduces the slip rotation speed of the first clutch CL1 by increasing the second clutch input rotation speed, thereby lowering the temperature of the first clutch CL1 together with the inverter temperature as shown in the temperature characteristic of FIG. Can do. When the vehicle stops on the uphill road, the second clutch input speed is increased to increase the slip speed of the second clutch CL2 and the temperature of the second clutch CL2 rises. When the temperature rises, control is performed to reduce the second clutch input rotational speed.

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

(1) A hybrid vehicle having a first clutch CL1 for connecting / disconnecting the engine Eng and the motor generator MG in the hybrid drive system, and limiting the motor output torque when the temperature of the inverter 3 connected to the motor generator MG exceeds the upper limit temperature. (FR hybrid vehicle) control device, inverter temperature detection means (inverter temperature sensor 26) for detecting the temperature of the inverter 3, and target drive based on driver operation (accelerator opening APO) and vehicle state (vehicle speed VSP) Torque Td ^* is determined, and this target drive torque Td ^* is divided into a target engine torque transmitted after passing through the first clutch CL1 and a target motor torque output from the motor generator MG, and based on each torque distribution ratio, An integrated controller that controls the operating points of the engine Eng, the motor generator MG, and the first clutch CL1. (Integrated controller 10, FIG. 2) and a temperature lower than the inverter upper limit temperature and the upper limit set value T _{Emp_INV_maxth,} the temperature detection value of the inverter 3 is determined to be the upper limit set value T _{Emp_INV_maxth} above, the First clutch torque capacity control means (FIG. 7) for performing control to increase the torque capacity target value for the first clutch CL1. For this reason, when the vehicle is stopped on the uphill road, the vehicle stopped state can be maintained without rolling back while suppressing an increase in the inverter temperature.

(2) The first clutch torque capacity control means (FIG. 7) sets the temperature lower than the upper limit set value _{Temp_INV_maxth} as the lower limit set value _{Temp_INV_minth,} and increases the torque capacity target value for the first clutch CL1. When it is determined that the temperature detection value of the inverter 3 has become equal to or lower than the lower limit set value _{Temp_INV_minth} , control is performed to decrease the target torque capacity value for the first clutch CL1. For this reason, a rise in the first clutch temperature accompanying an increase in the target torque capacity value for the first clutch CL1 is suppressed, and overheating deterioration of the first clutch CL1 can be prevented.

(3) Motor rotation number detection means (motor rotation number sensor 21) for detecting the rotation speed of the motor generator MG is provided, and the first clutch torque capacity control means (FIG. 7) measures the detected value of the motor rotation number in advance. Based on the temperature characteristics of the inverter 3 (FIG. 8), an inverter upper limit temperature torque calculation unit (step S714) for calculating an inverter upper limit temperature torque T _{INV_MAX} that suppresses the temperature rise of the inverter 3, and the target drive torque Td ^* wherein a first clutch torque capacity lower limit calculating section by the difference of the inverter upper limit temperature torque T _{INV_MAX} calculates the first clutch torque capacity lower limit value T _{CL1_MIN} (steps S715). For this reason, the temperature increase of the inverter 3 can be reliably suppressed by the increase control of the torque capacity target value to the first clutch CL1.

(4) The first clutch torque capacity control means (FIG. 7) includes an inverter margin temperature calculating unit (step S711) for calculating an inverter margin temperature _{Temp_mag_INV} from the inverter temperature detection value to the inverter upper limit temperature, and the inverter margin temperature. A first clutch torque capacity upper limit calculating unit (step S716) that calculates a first clutch torque capacity upper limit _{TCL1_MAX} that increases the torque as T _{emp_mag_INV} is lower. For this reason, the lower the inverter margin temperature _{Temp_mag_INV} , the higher the engine torque distribution, and accordingly, the lower the motor torque distribution, the higher the temperature of the inverter 3 can be suppressed with good response.

(5) First clutch temperature detection means (first clutch temperature sensor 22) for detecting the temperature of the first clutch CL1 is provided, and the first clutch torque capacity control means (FIG. 7) is provided with a first clutch temperature detection value. To a first clutch margin temperature _{Temp_mag_cl1} from the first clutch upper limit temperature to the first clutch margin temperature _{Temp_mag_cl1} , and a first clutch torque that increases as the first clutch margin temperature _{Temp_mag_cl1} increases. A first clutch torque capacity target value calculation unit (step S717) for calculating the capacity target value _Tcl1 ^* . Therefore, as referred to the first clutch allowance temperature T _{Emp_mag_cl1} is set high high as the engine torque distribution, the first clutch torque capacity increase control in accordance with the temperature increase margin in the range of the first clutch allowance temperature T _{Emp_mag_cl1} By doing so, the temperature rise of the inverter 3 can be suppressed with good response while preventing overheating of the first clutch CL1.

  (6) A first clutch input having a second clutch CL2 for connecting / disconnecting the motor generator MG and the driving wheels (left and right rear wheels RL, RR) in the hybrid drive system, and detecting an input rotational speed of the first clutch CL1. Rotational speed detection means (engine rotational speed sensor 12), second clutch output rotational speed detection means (second clutch output rotational speed sensor 24) for detecting the output rotational speed of the second clutch CL2, and the first clutch input A second control is performed to increase the target rotational speed input value to the second clutch CL2 by controlling the rotational speed of the motor generator MG with the rotational speed detection value as the upper limit value and the second clutch output rotational speed as the lower limit value. 2 clutch input rotation speed control means (FIG. 11). For this reason, the slip rotation speed of the first clutch CL1 is reduced, and the temperature of the first clutch CL1 can be lowered. Then, by controlling both the torque capacity and the slip rotation speed of the first clutch CL1, the inverter temperature (heat generation amount) and the first clutch temperature (heat generation amount) can be freely set. As a result, for example, Even when the temperature of both the inverter 3 and the first clutch CL1 rises, the inverter temperature and the first clutch temperature can be lowered simultaneously.

(7) First clutch temperature detecting means (first clutch temperature sensor 22) for detecting the temperature of the first clutch CL1, and second clutch temperature detecting means (second clutch temperature for detecting the temperature of the second clutch CL2). The second clutch input rotation speed control means (FIG. 11) is provided with a first clutch margin temperature _{Temp_mag_cl1} from the first clutch temperature detection value to the first clutch upper limit temperature and the second clutch temperature detection value. clutch allowance temperature calculator for calculating the second clutch allowance temperature T _{Emp_mag_cl2} until the second clutch limit temperature (step S721), the second clutch allowance temperature T _{Emp_mag_cl2} said first deviation [Delta] T _{Emp_mag_cl} clutch allowance temperature T _{Emp_mag_cl1} is A second clutch input rotation speed target value calculation unit (step S722) that performs control to increase the input rotation speed target value to the second clutch CL2 as the value increases. . For this reason, by monitoring the temperature rise allowance of both clutches CL1 and CL2, the temperature rise of the first clutch CL1 can be lowered with better response as the temperature rise allowance of the second clutch CL2 is larger.

(8) Inverter temperature detection means (inverter temperature sensor 26) for detecting the temperature of the inverter 3 is provided, and the second clutch input rotation speed control means (FIG. 11) is an inverter from the inverter temperature detection value to the inverter upper limit temperature. Inverter margin temperature calculation unit (step S723) that calculates margin temperature _{Temp_mag_INV} , and when the inverter margin temperature _{Temp_mag_INV} is small, the second clutch input rotational speed target value ω _cl2i ^* can be increased even if the rotational speed is increased further. A second clutch input rotation speed target value correction unit (step S724) that corrects the temperature to be _{equal to} or higher than the non-lock rotation speed ω _{UN_LOCK at which the} temperature does not rise. For this reason, when the inverter 3 is in a high temperature state, the temperature of the first clutch CL1 can be lowered with good response while suppressing the temperature rise of the inverter 3.

  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, the first clutch temperature sensor 22 is used as the first clutch temperature detection means, the second clutch temperature sensor 25 is used as the second clutch temperature detection means, and the inverter temperature sensor 26 is used as the inverter temperature detection means. However, a means for detecting or calculating the first clutch heat generation amount, the second clutch heat generation amount, or the inverter heat generation amount may be used.

  In the first embodiment, as the first clutch torque capacity control means, the example is shown in which the inverter is returned from the torque capacity increase control when the inverter temperature reaches the lower limit set value. For example, after the time of a predetermined timer value has elapsed, An example of returning from the increase control is also possible.

  In the first embodiment, the application example to the FR hybrid vehicle having the second clutch in the drive system is shown. However, the FR hybrid vehicle or FF having only the first clutch (engine clutch) without having the second clutch in the drive system. The present invention can also be applied to a hybrid vehicle control device. In the first embodiment, an example in which the frictional engagement element built in the automatic transmission is used as the second clutch is shown. However, the hybrid drive system is provided with an independent second clutch at the upstream position or the downstream position of the transmission. It can also be applied to vehicles.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an overall system diagram illustrating a parallel-type FR hybrid vehicle (an example of a hybrid vehicle) by rear wheel drive to which a control device according to a first embodiment is applied. It is a flowchart which shows the integrated control process performed in the integrated controller 10 of the FR hybrid vehicle to which the control apparatus of Example 1 was applied. It is a figure which shows an example of the target drive torque calculation map which calculates a target drive torque by using the accelerator opening APO and the vehicle speed VSP as parameters. It is a figure which shows an example of a 2nd clutch torque capacity-hydraulic pressure conversion map. It is a figure which shows an example of a 2nd clutch torque oil pressure-current conversion map. It is a flowchart which shows the setting process (step S5 of FIG. 2) of 2nd clutch control mode CL2MODE performed with the integrated controller 10 of FR hybrid vehicle to which the control apparatus of Example 1 was applied. It is a flowchart which shows the calculation process (step S7 of FIG. 2) of 1st clutch torque capacity target value _TCL1 ^* performed with the integrated controller 10 of the FR hybrid vehicle to which the control apparatus of Example 1 was applied. It is an inverter temperature characteristic figure which shows the relationship of the inverter upper limit temperature torque with respect to the 2nd clutch input rotation speed. It is a 1st clutch torque capacity upper limit calculation map which shows the relationship of the 1st clutch torque capacity upper limit with respect to inverter margin temperature. It is a 1st clutch torque capacity target value calculation map which shows the relationship of the 1st clutch torque capacity target value with respect to 1st clutch margin temperature. It is a flowchart which shows the calculation process (step S7 of FIG. 2) of 2nd clutch input rotation speed target value (omega) _cl2i ^* performed with the integrated controller 10 of the FR hybrid vehicle to which the control apparatus of Example 1 was applied. It is a basic 2nd clutch input rotation speed target value calculation map which shows the relation of the basic 2nd clutch input rotation speed target value with respect to the deviation of each clutch margin temperature. It is a 2nd clutch input rotation speed correction value calculation map which shows the relationship of the 2nd clutch input rotation speed correction value with respect to inverter margin temperature. It is a flowchart which shows the 1st clutch electric current command value calculation process (step S20 of FIG. 2) performed in the integrated controller 10 of FR hybrid vehicle to which the control apparatus of Example 1 was applied. It is a figure which shows an example of the relationship characteristic of the clutch torque capacity | capacitance of a 1st clutch, a clutch stroke, and a diaphragm spring reaction force. It is a block diagram which shows a 1st clutch stroke control system. It is a figure which shows an example of modeling (map) of the reaction force-stroke characteristic created from the diaphragm spring reaction force characteristic with respect to a clutch stroke. It is a time chart which shows an example of the simulation result of the rotation speed, clutch torque capacity, engine / motor torque, drive torque, and temperature in comparative example control at the time of hill hold. It is a time chart which shows an example of the simulation result of the rotation speed, the clutch torque capacity, the engine / motor torque, the driving torque, and the temperature in the inverter overheat suppression control in the first embodiment at the time of hill hold. It is a time chart which shows an example of the simulation result of the rotation speed, clutch torque capacity, engine / motor torque, drive torque, and temperature in the overheat suppression control of the inverter 3 and the first clutch CL1 in the first embodiment at the time of hill hold.

Explanation of symbols

Eng engine
FW flywheel
CL1 1st clutch
MG motor generator
CL2 2nd clutch
AT automatic transmission
PS propeller shaft
DF differential
DSL left drive shaft
DSR right drive shaft
RL Left rear wheel (drive wheel)
RR Right rear wheel (drive wheel)
1 engine controller 2 motor controller 3 inverter 4 battery 5 first clutch controller 6 first clutch hydraulic unit 7 AT controller 8 second clutch hydraulic unit 9 brake controller 10 integrated controller 11 CAN communication line 12 engine speed sensor (first clutch input) Rotation speed detection means)
13 resolver 14 hydraulic actuator 14a piston 15 first clutch stroke sensor 16 accelerator opening sensor 17 vehicle speed sensor 18 inhibitor switch 19 wheel speed sensor 20 brake switch sensor 21 motor rotation speed sensor (motor rotation speed detection means)
22 1st clutch temperature sensor (1st clutch temperature detection means)
23 Second clutch input rotational speed sensor (second clutch input rotational speed detection means)
24 Second clutch output rotational speed sensor (second clutch output rotational speed detection means)
25 Second clutch temperature sensor (second clutch temperature detecting means)
26 Inverter temperature sensor (Inverter temperature detection means)

Claims (6)

In a hybrid vehicle control apparatus having a first clutch for intermittently connecting an engine and a motor generator in a hybrid drive system, and limiting a motor output torque when a temperature of an inverter connected to the motor generator exceeds an upper limit temperature,
Inverter temperature detecting means for detecting the temperature of the inverter;
Motor rotation number detecting means for detecting the rotation number of the motor generator;
A target drive torque is determined based on a driver's operation and a vehicle state, and the target drive torque is distributed to a basic engine torque command value and a basic motor torque command value, and the engine, the motor generator, and the Integrated control means for controlling each operating point of the first clutch;
An inverter upper limit temperature torque calculation unit for calculating an inverter upper limit temperature torque that suppresses temperature increase of the inverter based on a motor rotation speed detection value and a temperature characteristic of the inverter measured in advance, and an inverter from the inverter temperature detection value to the inverter upper limit temperature An inverter margin temperature calculation unit for calculating a margin temperature; a first clutch torque capacity lower limit value calculation unit for calculating a first clutch torque capacity lower limit value based on a difference between the target drive torque and the inverter upper limit temperature torque; and the inverter margin temperature comprising a first clutch torque capacity limit calculator for calculating the first clutch torque capacity upper limit value is to lower the high torque, and first clutch torque capacity control means having a a,
The first clutch torque capacity control means sets a temperature lower than the inverter upper limit temperature as an upper limit set value, and sets the basic engine torque command value as the first clutch torque when the detected temperature value of the inverter is less than the upper limit set value. When it is determined that the detected temperature value of the inverter is equal to or higher than the upper limit set value as the target capacity value, the value limited by the first clutch capacity lower limit value and the first clutch capacity upper limit value is set as the first clutch torque. set as the capacity target value, it performs control for increasing the torque capacity target value to the first clutch,
The integrated control means performs control to decrease the motor torque distribution ratio by an amount corresponding to an increase in the engine torque distribution ratio transmitted from the engine after passing through the first clutch by torque capacity control of the first clutch. A control device for a hybrid vehicle. In the hybrid vehicle control device according to claim 1,
The first clutch torque capacity control means sets a temperature lower than the upper limit set value as a lower limit set value, and increases a torque capacity target value for the first clutch so that the detected temperature value of the inverter becomes lower than the lower limit set value. When it is determined that the torque capacity has been reached, control is performed to decrease the target torque capacity value for the first clutch. In the hybrid vehicle control device according to claim 1 or 2 ,
Providing a first clutch temperature detecting means for detecting the temperature of the first clutch;
The first clutch torque capacity control means includes a first clutch margin temperature calculating unit that calculates a first clutch margin temperature from a first clutch temperature detection value to a first clutch upper limit temperature, and a higher first clutch margin temperature. A control apparatus for a hybrid vehicle, comprising: a first clutch torque capacity target value calculation unit that calculates a first clutch torque capacity target value for high torque. In the control apparatus of the hybrid vehicle described in any one of Claim 1- Claim 3 ,
The hybrid drive system has a second clutch for intermittently connecting the motor generator and the drive wheel,
First clutch input rotational speed detection means for detecting an input rotational speed of the first clutch;
Second clutch output rotational speed detection means for detecting the output rotational speed of the second clutch;
Control for increasing the target rotational speed input value to the second clutch by controlling the rotational speed of the motor generator with the first clutch input rotational speed detection value as an upper limit value and the second clutch output rotational speed as a lower limit value Second clutch input rotational speed control means for performing
A control apparatus for a hybrid vehicle, comprising: In the hybrid vehicle control device according to claim 4 ,
First clutch temperature detecting means for detecting the temperature of the first clutch;
A second clutch temperature detecting means for detecting the temperature of the second clutch is provided;
The second clutch input rotational speed control means includes a first clutch margin temperature from the first clutch temperature detection value to the first clutch upper limit temperature and a second clutch margin temperature from the second clutch temperature detection value to the second clutch upper limit temperature. And a second clutch input that performs control to increase the target rotational speed target value to the second clutch as the deviation between the second clutch margin temperature and the first clutch margin temperature increases. A control device for a hybrid vehicle, comprising: a target rotation speed calculation unit. In the hybrid vehicle control device according to claim 4 or 5 ,
Inverter temperature detection means for detecting the temperature of the inverter is provided,
The second clutch input rotation speed control means includes an inverter margin temperature calculation section for calculating an inverter margin temperature from the inverter temperature detection value to the inverter upper limit temperature, and, when the inverter margin temperature is small, a second clutch input rotation speed target value. And a second clutch input rotational speed target value correction unit that corrects the rotational speed so that the inverter temperature does not increase even when the rotational speed is further increased. .

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