JP2010188807A - Control device for electric vehicle - Google Patents

Abstract

To provide a control device for an electric vehicle capable of suppressing an increase in temperature of an inverter and a clutch when the motor does not rotate or performs extremely low speed rotation in a motor torque output state in which motor torque is transmitted to a drive wheel.
An integrated controller 17 is configured such that an inverter temperature is set to a preset inverter temperature threshold in a state where motor torque is output from a motor generator MG to the left and right drive wheels LT and RT via a second clutch CL2. If exceeded, an inverter temperature suppression process is executed to increase the slip amount of the second clutch CL2 by increasing the motor rotation speed. On the other hand, if the clutch temperature exceeds a preset clutch temperature threshold, In addition, the control apparatus for the electric vehicle is characterized in that the clutch temperature suppression process is performed to reduce the slip amount of the second clutch CL2 by reducing the motor rotation speed.
[Selection] Figure 1

Description

  The present invention relates to a control device for an electric vehicle provided with an engine and a motor as drive sources, and more particularly to a technique for preventing heating of an inverter during hill hold control.

  Conventionally, it is known to perform hill hold control for keeping a vehicle in a stopped state on an uphill road. When such hill hold control is performed in a vehicle having a motor as a drive source, the inverter is heated because the motor is in a locked state in which the drive force is generated and is not rotated.

  In this case, for example, Japanese Patent Application Laid-Open No. H10-228443 is known which cools the inverter. In this prior art, when the vehicle is in the hill hold state, when the inverter temperature from the temperature sensor is equal to or higher than the limit start temperature at which the load factor of the motor generator for driving the vehicle starts to be limited, the inverter device is cooled. The target flow rate of the cooling water was set to the maximum flow rate, and the water pump circulated cooling water with a flow rate matching the target flow rate through the refrigerant path.

JP 2008-72818 A

  However, the conventional control device for an electric vehicle described above, for example, when the vehicle is stopped by a driver's accelerator operation, such as during hill hold on an uphill road, continues to generate torque in a locked state where the motor does not rotate. There was a possibility that cooling could not be in time for the inverter temperature rise.

  The present invention has been made paying attention to the above problems, and even when the motor continues to be driven in a locked state or extremely low speed rotation state such as a hill hold in which the vehicle is stopped on an uphill road, the temperature of the inverter and the clutch is increased. An object of the present invention is to provide a control device for an electric vehicle capable of suppressing the above.

  In order to achieve the above object, an electric vehicle control apparatus according to the present invention includes a clutch capable of disconnecting the motor side and the drive wheel side in the middle of the driving force transmission path between the motor and the drive wheel. If the inverter temperature detected by the inverter temperature detection means exceeds a preset inverter temperature threshold in a state where the motor torque is transmitted to the drive wheel side via the clutch by driving the motor Inverter temperature suppression processing is executed to increase the clutch slip amount by increasing the motor rotation speed. On the other hand, if the clutch temperature detected by the clutch temperature detection means exceeds a preset clutch temperature threshold, Control means for performing clutch temperature suppression processing for reducing the slip amount of the clutch by reducing the motor rotation speed is provided. And a control device for an electric vehicle.

  In the control apparatus for an electric vehicle according to the present invention, while the drive torque is output by the motor, such as during hill hold control, the motor or inverter generates heat as in the case where the motor rotation speed does not increase compared to the drive torque. In a situation that is likely to occur, when the inverter temperature exceeds the inverter temperature threshold, the control means executes inverter temperature suppression processing.

  By this inverter temperature suppression process, the motor rotation speed is increased, the clutch slip amount is increased, the motor rotation speed is increased, and the heat generation of the inverter can be suppressed.

  On the other hand, when the clutch temperature detected by the clutch temperature detecting means exceeds the clutch temperature threshold by slipping the clutch, the control means executes the clutch temperature suppression process to reduce the motor rotation speed and to slip the clutch. Reduce the amount. As a result, the slip amount of the clutch can be reduced without changing the output rotational speed of the clutch. Since the clutch slip amount is reduced in this way, heat generation of the clutch can be suppressed.

  Thus, according to the present invention, it is possible to provide a control device for an electric vehicle capable of suppressing the temperature rise of the inverter and the clutch during hill hold.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an overall system diagram showing a rear-wheel drive FR hybrid vehicle (an example of a vehicle) to which a control device according to a first embodiment is applied. It is a flowchart which shows the first half part of the flow of the arithmetic processing performed in the integrated controller 17 of FR hybrid vehicle to which the control apparatus of Example 1 was applied. It is a flowchart which shows the latter half part of the flow of the arithmetic processing performed in the integrated controller 17 of FR hybrid vehicle to which the control apparatus of Example 1 was applied. It is a target drive torque characteristic figure which shows an example of the map used for calculating the target drive torque Td ^* in Example 1. FIG. FIG. 3 is a target charge / discharge amount characteristic diagram illustrating an example of a target charge / discharge amount characteristic (motor torque) with respect to a battery charge amount SOC in the first embodiment. Shows a map used from the final second clutch torque capacity command value T _CL2 ^* to compute the second clutch current command value I _cl2 ^* in Example 1, (a) is a clutch hydraulic pressure characteristic diagram for the clutch torque capacity FIG. 6B is a second clutch current command value characteristic diagram with respect to the clutch hydraulic pressure. It is a flowchart which shows the detail of the process which sets 2nd clutch control mode CL2MODE in step S5. It is a flowchart which shows the flow of a calculation process of 2nd clutch input rotation speed target value (omega) _cl2i ^* when performing slip rotation speed control in the 2nd clutch CL. It is an inverter temperature characteristic figure which shows the relationship between a motor rotation speed and inverter temperature. 7 is a basic second clutch input rotation speed target value calculation map used for calculating a basic second clutch input rotation speed target value _{ωcl2i_base} ^* in step S84. 7 is a second clutch input rotation speed correction value calculation map used for correcting the second clutch input rotation speed target value in step S87. It is a flowchart which shows the flow of the process which calculates 1st clutch electric current command value _Icl1 ^* in step S20. 7 is a map showing clutch capacity-stroke characteristics used for calculating a first clutch stroke target value x _sccl1 ^* in step S201. FIG. 5 is a control block diagram showing in detail a calculation process of a first clutch hydraulic pressure command value _Pcl1 in step S202. FIG. 6 is a reaction force (hydraulic pressure) -stroke characteristic diagram of a clutch mechanism portion of a first clutch CL1. It is a block diagram which shows the structure which performs an inverter temperature suppression process. It is a block diagram which shows the structure which performs a clutch temperature suppression process. 3 is a time chart showing an operation example of the first embodiment. 6 is a time chart showing an example of a comparative operation with Example 1. It is a flowchart which shows the first half part of the flow of the inverter temperature suppression process and clutch temperature suppression process of Example 2. It is a flowchart which shows the latter half part of the flow of the inverter temperature suppression process of Example 2, and a clutch temperature suppression process. FIG. 6 is a heat generation characteristic diagram of an inverter 8 in Example 2. It is a time chart which shows the operation example of the inverter temperature suppression process at the time of the hill hold of Example 2. FIG. It is a time chart which shows operation in the case of improving responsiveness at the time of torque capacity reduction of the 2nd clutch CL2 in Step S2004 of Example 2. 6 is a time chart illustrating an operation example of clutch temperature rise suppression processing according to the second embodiment. is there.

    Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  An electric vehicle control apparatus according to an embodiment of the present invention is a clutch that is provided in the middle of a driving force transmission path between a motor (MG) and driving wheels (LT, RT) and that can cut off the motor side and the driving wheel side. (CL2), an inverter (8) for converting power between the motor and the power source, clutch temperature detecting means (16) for detecting the temperature of the clutch (CL2), and detecting the temperature of the inverter (8) An inverter temperature detecting means (14) for detecting the state of the vehicle, and controlling the driving force of the motor based on the vehicle state detected by the vehicle state detecting means, And a control means (17) for controlling an engaged state, wherein the control means (17) drives the motor to drive the driving wheel via the clutch. When the inverter temperature detected by the inverter temperature detecting means (14) exceeds a preset inverter temperature threshold value while the motor torque is being transmitted to the motor torque, the motor rotational speed is increased and the motor temperature is increased. When the inverter temperature suppression process for increasing the slip amount of the clutch (CL2) is performed, and the clutch temperature detected by the clutch temperature detection means (16) exceeds a preset clutch temperature threshold, A control apparatus for an electric vehicle, characterized by executing a clutch temperature suppression process for reducing the motor rotation speed and reducing the slip amount of the clutch (CL2).

  Based on FIGS. 1-19, the control apparatus of the electric vehicle of Example 1 of the best embodiment of this invention is demonstrated.

  FIG. 1 is an overall system diagram showing a rear-wheel drive FR hybrid vehicle (an example of a hybrid vehicle) to which the control device of the first embodiment is applied.

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 according to the first embodiment includes an engine Eng, a first clutch CL1, a motor generator (motor) MG, a second clutch CL2, an automatic transmission AT, a final transmission, and the like. A gear FG, a left drive wheel LT, and a right drive wheel RT are provided.

  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 semi-electric vehicle travel mode (hereinafter referred to as “EV mode”). ) 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 disengaged 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 of a motor cyst traveling mode, a traveling power generation mode, and an engine traveling 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.

  “WSC mode” controls the motor generator MG at the time of P / N → D select start from “HEV mode” or D range start from “EV mode” or “HEV mode”. Then, the slip engagement state of the second clutch CL2 is maintained, and the clutch transmission torque passing through the second clutch CL2 starts while controlling the clutch torque capacity so that the required drive torque determined according to the vehicle state and the driver operation is achieved. Mode. “WSC” is an abbreviation for “Wet Start Clutch”.

  The engine Eng is capable of lean combustion, and the engine torque is controlled to coincide with 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.

  First clutch CL1 is interposed at a position between engine Eng and motor generator MG. As the first clutch CL1, for example, a dry clutch that is normally engaged (normally closed) 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 for 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 there.

The second clutch CL2 is a normally open wet multi-plate clutch or wet multi-plate brake, and generates transmission torque (clutch torque capacity) in accordance with clutch hydraulic pressure (pressing force). The second clutch CL2 passes 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 and RT via the automatic transmission AT and the final gear FG. introduce.
As shown in FIG. 1, the second clutch CL2 is engaged at each gear position of the automatic transmission AT, in addition to setting an independent clutch at a position between the motor generator MG and the automatic transmission AT. A clutch or a brake used as a frictional engagement element may be used. Further, it may be set at a position between the automatic transmission AT and the left and right drive wheels LT, 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 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, an inverter 8, A battery 9, an accelerator sensor 10, a road surface inclination angle sensor 30, an engine speed sensor 11, a transmission oil temperature sensor 12, a stroke sensor 13, an inverter temperature sensor 14, a first clutch oil temperature sensor 15, A second clutch oil temperature sensor 16, an integrated controller 17, a transmission controller 18, a clutch controller 19, an engine controller 20, a motor controller 21, and a battery controller 22 are provided.

  Inverter 8 performs DC / AC conversion and generates a drive current for motor generator MG. Battery 9 stores regenerative energy from motor generator MG via inverter 8.

The integrated controller 17 calculates the target drive torque Td ^* 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 transmitted to the controllers 18-22.

  The transmission controller 18 performs shift control so as to achieve the shift command from the integrated controller 17.

  The clutch controller 19 inputs sensor information from the second clutch input rotational speed sensor 6, the second clutch output rotational speed sensor 7, and the second clutch oil temperature sensor 16, and the first clutch hydraulic pressure command value from the integrated controller 17. And the second clutch hydraulic pressure command value, the solenoid valve current is controlled so as to realize the clutch hydraulic pressure (current) command value.

  The engine controller 20 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 17.

The motor controller 21 controls the motor generator MG so as to achieve the motor torque command value Tm ^* and the motor rotation speed command value (second clutch input rotation speed target value _ωcl2i ^* ) from the integrated controller 17.

  The battery controller 22 manages the state of charge (SOC) of the battery 9 and transmits the information to the integrated controller 17.

  Next, processing contents including the motor temperature suppression processing executed by the integrated controller 17 of the first embodiment will be described using the flowcharts shown in FIGS. 2 and 3. Note that the processing contents shown in both figures are executed at a constant sampling frequency.

In step S1, the battery charge SOC, the shift position of the automatic transmission AT, the input / output rotational speed of the second clutch CL2, the vehicle speed Vsp, the first clutch stroke measurement value _xscl1 , the inverter temperature T _{emp_INV} , the first and second clutches Data indicating the vehicle state such as temperatures T _{emp_cl1} and T _{emp_cl2} is received, and the process proceeds to the next step S2.

  In step S2, the accelerator opening Apo is measured, and the process proceeds to step S3.

In step S3, the target drive torque Td ^* is calculated from the accelerator opening Apo and the vehicle speed Vsp, and the process proceeds to step S4. Although not described in detail, the target drive torque Td ^* can be calculated based on, for example, a map as shown in FIG.

In step S4, the first clutch control mode flag fCL1 is determined and set based on 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. The first clutch control mode flag fCL1 is a mode in which the first clutch CL1 is engaged (fCL1 = 1, set in the HEV mode WSC mode such as when the engine is started), and a mode in which the first clutch CL1 is released (fCL1). = 0 and is set in the EV mode).

  Although detailed description of the setting of the first clutch control mode flag fCL1 is omitted here, for example, in a driving scene where the engine Eng is relatively inefficient such as starting at low acceleration, the EV mode driving is used. The first clutch CL1 is released (fCL1 = 0).

Further, when the battery charge amount SOC is equal to or less than a preset charge amount set value SOCth1, or the target drive torque Td ^* is equal to or greater than the maximum drive torque Td _max during EV mode travel, EV mode travel is difficult. In order to travel in the HEV mode, the first clutch CL1 is semi-engaged or fastened (fCL1 = 1). FIG. 5 shows an example of target charge / discharge amount characteristics (motor torque) with respect to the battery charge amount SOC. As described above, when the battery charge amount SOC is lower than the reference value, the target charge / discharge amount is set low and charged, and when the battery charge amount SOC is high, the target charge / discharge amount is set high and discharged. The
In the first embodiment, when the road surface inclination angle sensor 30 detects an uphill road having a predetermined angle or more, the first clutch CL1 is engaged without stopping the engine Eng even when the vehicle is stopped.

In step S5, the second clutch control mode CL2MODE is determined and set based on 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, and the process proceeds to step S7. The second clutch control mode CL2MODE determines whether the second clutch CL2 is controlled to be engaged, released, or slipped, and will be described in detail later.

In step S6, the share of the target drive torque Td ^* between the engine Eng and the motor generator MG is determined based on the control modes of the clutches CL1 and CL2 and the vehicle state. That is, the basic engine torque command value _{Te_base} ^* corresponding to the drive torque distribution amount of the engine Eng is determined, and the basic motor torque command value _{Tm_base} ^* corresponding to the drive torque distribution amount of the motor generator MG is determined, step S7. Proceed to Although various methods of torque distribution are conceivable, in this embodiment, the motor generator MG is allocated as much as possible, and the shortage with respect to the target drive torque Td ^* is allocated to the engine Eng.

In step S7, the first clutch input rotation speed target value that is the input rotation speed of each clutch CL1, CL2 from the inverter temperature T _{emp_INV} , each clutch temperature T _{emp_cl1} , T _{emp_cl2} , and the second clutch output shaft rotation speed measured value ω _{cl2o. ωcl1i} ^* and the second clutch input rotational speed target value _ωcl2i ^* are calculated. Details will be described later.

  In step S8, it is determined whether or not the slip rotation speed control of the first clutch CL1 is to be executed. When the slip rotation speed control is performed, the process proceeds to step S9, and when the slip rotation speed control is not performed, the process proceeds to step S11. Here, the execution (ON) condition of the first clutch slip rotation speed control is that the first clutch state determined in step S4 is set to slip or engagement, and the first clutch CL1 and the second clutch CL2 calculated in step S7 are set. Is the same value, and the actual slip rotation speed (first clutch input rotation speed-first clutch output rotation speed) absolute value is equal to or greater than a preset installation value. Otherwise, the slip rotation speed control is turned off and the process proceeds to S11. In addition, when performing the inverter temperature suppression process which is the characteristics of this invention, slip rotation speed control of the 1st clutch CL1 is performed.

In step S9, the engine speed command value _{Te_FB_ON} for speed control is calculated so that the first clutch input rotational speed target value _ωcl1i ^* and the first clutch input rotational speed measured value _ωcl1i match. Although various calculation methods are conceivable, in the first embodiment, calculation is performed according to the following equation (1) based on PI control. The actual calculation is calculated using a recurrence formula obtained by discretization by Tustin approximation or the like.
_{T e_FB_ON = {(K Pe s} + K Ie) / s} (ω clIi * -ω clIi) ·· (1)
Here, K _pe is an engine control proportional gain, _KIe is an engine control integral gain, and s is a differential operator.

In step S10, a first clutch torque capacity command value T _{cl1_FB_ON} for rotation speed control is calculated. Basically, it is set to the same value as the basic engine torque command value T _{e_base} ^* calculated in step S6. Further, correction may be performed by an F / B compensator configured to perform the same processing as in step S9.

In step S11, an internal state variable for calculating the engine speed command value _{Te_FB_ON} for rotation speed control described above is initialized.

In step S12, the clutch torque capacity command value is classified according to whether the rotational speed control is not performed, that is, when the first clutch CL1 is engaged, when the first clutch CL1 is engaged, or when the engaged state → rotational speed control (slip control) is performed. T _{cl1_FB_OFF} is calculated.
(When concluded)
If ^{_{1-a) T clI_z1 * <}} Te * × K safe determined by the following equation (2).
T _{cl1_FB_OFF} = T _{clI_z1} ^* + ΔT _cl1LU (2)
If _{1-b) T} clI_z1 * a ≧ Te ^* × _{K safe} determined by the following equation (3).
T _{cl1_FB_OFF} F = Te ^* × Ksafe (3)
(When opening)
T _{cl1_FB_OFF} = 0 (4)
(When fastening → slipping)
^{_{T cl1_FB_OFF = T clI_z1 * -ΔT cl1slp}} ··· (5)
However, K _safe is the clutch safety factor coefficient (> 1), ΔT _cl1LU is the torque capacity change rate at the time of transition from slip (or release), ΔT _cl1slp is the torque capacity change rate at the time of engagement → slip transition, and T _{clI_z1} ^* is the final The first torque command value is the previous value.

  In step S13, it is determined whether to execute slip rotation speed control (WSC) of the second clutch CL2. In this case, the second clutch control mode CL2MODE set in step S5 is the slip mode (CL2MODE = 2), and the actual slip rotational speed (second clutch input rotational speed−second clutch output rotational speed). If the absolute value is equal to or greater than the set value, the slip rotation speed control is turned on and the process proceeds to step S14. On the other hand, if the second clutch control mode CL2MODE is set to release (CL2MODE = 0) or engaged (CL2MODE = 1), the slip rotation speed control is turned OFF and the process proceeds to step S16. In addition, when performing the inverter temperature suppression process which is the characteristics of this invention, slip rotation speed control of the 2nd clutch CL2 is performed.

In step S14, a rotational speed control motor torque command value _{Tm_FB_ON} is calculated so that the second clutch input rotational speed target value _ωcl2i ^* _matches the second clutch input rotational speed measured value _ωcl2i, and the process proceeds to step S15. . Various calculation methods of the rotational speed control motor torque command value _{Tm_FB_ON} can be considered. In the first embodiment, calculation is performed by PI control based on the following equation (1). In the first embodiment, this calculation is calculated using a recurrence formula obtained by discretization by Tustin approximation or the like.
_{T m_FB_ON = {(K pm S} + K lm) / s} (ω CL2i * -ω CL2i) ··· (6)
In the above equation (1), K _pm is a proportional gain for motor control, and K _lm is an integral gain for motor control.

In step S15, the second clutch torque capacity command value _{Tcl2_FB_ON} for rotation speed control is calculated, and the process proceeds to step S17. The second clutch torque capacity command value T _{cl2_FB_ON} for rotation speed control is basically the same value as the target drive torque Td ^* . Further, correction may be performed by a feedback compensator in the same manner as the first clutch CL1.

In step S16, internal state variables for calculating the above-described rotation speed control motor torque command value _{Tm_FB_ON} and rotation speed control second clutch torque capacity command value _{Tcl2_FB_ON} are initialized, and the process proceeds to step S18.

In step S17, the case where the rotational speed control is not performed, that is, the case where the second clutch CL2 is engaged, the case where the second clutch CL2 is engaged, and the case where the engaged state → the rotational speed control is performed (slip state) are classified. The clutch torque capacity command value _{Tcl2_FB_OFF} is calculated, and the process proceeds to step S18.

Here, the clutch torque capacity command value _{Tcl2_FB_OFF} is the following formulas (7), (8), (9), and (10) when _engaged , when released, and when performing rotational speed control from the engaged state, respectively. )
(When concluded)
<T _{cl2_z1} ^* <Td ^* × K _safe >
T _{cl2_FB_OFF} = T _{cl2_z1} ^* + ΔT _cl2LU (7)
< _{Tcl2_z1} ^* _≧ Td ^* × K _safe >
T _{cl2_FB_OFF} = Td ^* × K _safe (8)
(When releasing)
T _{Cl2_FB_OFF} = 0 (9)
(When fastening → slipping)
^{_{T cl2_FB_OFF = T cl2_Z1 * -ΔT cl2slp}} ··· (10)
However, in the above formulas (7) to (10), ΔT _cl2LU is the torque capacity change rate during slip (or release) → engagement transition, ΔT _cl2slp is the torque capacity change rate during engagement → slip transition, and T _{cl2_Z1} ^* is The final second torque command value is the previous value.

In step S18, the final first clutch torque capacity command value _Tcl1 ^* is determined based on the following conditions, and the process proceeds to the next step S19. In determining the final first clutch torque capacity command value T _cl1 ^* , when the engine is not starting, it is determined based on the following equation (11), and when the engine is starting, the following equation (12 ).
^{_{T cl1 * = T cl1_crank_OFF ··· (}} 11)
^{_{T cl1 * = T cl_crank_ON ··· (}} 12)
In step S19, the final second clutch torque capacity command value _Tcl2 ^* is determined, and the process proceeds to step S20. In determining the final second clutch torque capacity command value T _cl2 ^* , when the slip rotation speed control is being performed, the following expression (13) is obtained. When the slip rotation speed control is stopped, the following expression (14 )
T _cl2 ^* = T _{cl2_FB_ON} (13)
T _cl2 ^* = T _{cl2_FB_OFF} (14)
In step S20, the first clutch current command value I _cl1 ^* to the solenoid valve that controls the engagement hydraulic pressure of the first clutch CL1 is calculated from the final first clutch torque capacity command value T _cl1 ^* . A detailed calculation method of the first clutch current command value I _cl1 ^* will be described later.

In step S21, the second clutch current command value I _cl2 ^* to the solenoid valve that controls the hydraulic pressure applied to the second clutch CL2 is _calculated from the final second clutch torque capacity command value T _cl2 ^* . The calculation of the second clutch current command value I _cl2 ^* is performed based on a map shown in FIG. 6 created based on previously acquired characteristics. 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, a motor torque command value Tm ^* is determined, and the process proceeds to step S23. In determining the motor torque command value Tm ^* , when the second clutch CL2 is under rotational speed control, it is determined based on the following equation (15), and when the second clutch CL2 rotational speed control is stopped: , Based on the following equation (16).
Tm ^* = _{Tm_FB_ON} (15)
Tm ^* = _{Tm_base} (16)
In step S23, final engine torque command value Te ^* is determined, and the process proceeds to step S24. In determining the final engine torque command value Te ^* , when the first clutch CL1 is under rotation control, it is determined based on the following equation (17), and when the first clutch CL1 is under rotation control stop: Is determined based on the following equation (18).
Te ^* = _{Te_FB_ON} (17)
Te ^* = _{Te_base} ^* (18)
In step S24, the second clutch current command value _I obtained in step S20 to S23 _cl2 ^*, first clutch current command value _{I cl1} ^*, the motor torque command value Tm ^*, the final engine torque command value Te ^* of each controller 18 To ~ 22. Thus, the flow of processing executed in one sampling cycle in the integrated controller 17 is completed.

(Details of setting method of second clutch control mode CL2MODE)
Next, details of the setting method of the second clutch control mode CL2MODE in step S5 will be described. 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. The details will be described below with reference to the flowchart shown in FIG.

  In S51, the first clutch control mode flag fCL1 is determined. If the first clutch control mode flag fCL1 is in the release mode (fCL1 = 0 and the engine is stopped), the process proceeds to step S52, and the engagement mode (fCL1 = 1 is set). In the case of (engine start), the process proceeds to S55.

  In S52, it is determined whether or not the vehicle speed Vsp is zero (stop). If the vehicle speed Vsp is stopped, the process proceeds to step S53, and otherwise, the process proceeds to step S54.

  In S53, the second clutch control mode CL2MODE is set to the engagement mode (CL2MODE = 1), and one process is completed. In S54, the second clutch control mode CL2MODE is set to the slip mode (CL2MODE = 2), and one process is completed.

  In S55, it is determined whether or not the vehicle speed Vsp is higher than a preset value Vth1 (for example, the lowest vehicle speed at which the engine Eng can be started). If the vehicle speed Vsp is lower than the preset value Vth1, the process proceeds to step S56. If it is also higher, the process proceeds to step S58.

In step S56, 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 S57.

  In step S57, the second clutch control mode CL2MODE is set to the release mode (CL2MODE = 0), and one process is completed.

  In step S58, it is determined whether or not the previous second clutch control mode CL2MODE is the engagement mode (CL2MODE = 1). If the engagement mode is the engagement mode, the process proceeds to step S53. Otherwise, the process proceeds to step S59.

In step S59, it is determined whether or not the engine speed measurement value _ωe and the second clutch slip rotation speed measurement value _ωcl2slp satisfy the following slip continuation conditions. If so, the process proceeds to step S54 to start or continue slipping. If the slip continuation condition is not satisfied, the process proceeds to step S53 to end the slip and shift to the fastening mode. Here, the case where the slip continuation condition is satisfied is a case where _ωe ≠ _ωcl2i (that is, the first clutch CL1 is released or slipped) or _ωcl2slp > _ωcl2slpth is satisfied.

Next, details of the calculation method of the input rotation speed target values ω _cl1i ^* and ω _cl2i ^* of the clutches CL1 and CL2 in step S7 will be described.
(Calculation method of first clutch input rotational speed target value ω _cl1i ^* )
First, a method for calculating the first clutch input rotational speed target value _ωcl1i ^* will be described.
As shown in FIG. 1, since the input side of the first clutch CL1 is directly connected to the engine Eng, it is necessary to set at least a rotational speed at which the engine Eng does not stall, and the lower one of the first clutch CL1 The calorific value becomes smaller. Therefore, the first clutch input rotational speed target value _ωcl1i ^* is set to a higher value of the lowest rotational speed _{ωe_MIN at} which the engine does not stall and the second clutch input rotational speed target value _ωcl2i ^* .

(Calculation method of second clutch input rotational speed target value _ωcl2i ^* )
Next, the flow of the calculation process of the second clutch input rotation speed target value _ωcl2i ^* when the slip rotation speed control is performed in the second clutch CL will be described based on the flowchart of FIG.

In step S81, a first clutch margin temperature T _{emp_mag_cl1} and a second clutch margin temperature T _{emp_mag_cl2} which are differences from the first clutch temperature T _{emp_cl1} and the second clutch temperature T _{emp_cl2} to the upper limit temperatures of the clutches CL1 and CL2 are calculated.

At step S82, the inverter temperature _{T Emp_INV} may determine whether preset inverter temperature threshold value _{T Emp_INV_th} above, the process proceeds to step S83 at the inverter temperature threshold value _{T Emp_INV_th} or more, the process proceeds to step S85 below the inverter temperature threshold value _{T Emp_INV_th} . Note that the inverter temperature threshold value T _{emp_INV_th} is equal to or lower than the inverter upper limit temperature and has a margin with respect to the upper limit value, so that even when the target drive torque Td ^* further increases, the inverter temperature threshold value T _{emp_INV_th} can be dealt with.

In step S83, the inverter upper limit temperature rotational speed ω _{TINV_MAX} is calculated from the previous motor command value T _{m_z1} ^* based on the inverter temperature characteristics shown in FIG. 9 set in advance as a map.

In step S84, the smaller one of the inverter upper limit temperature rotational speed ω _{TINV_MAX} and 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. Actually, calculation is performed based on the basic second clutch input rotation speed target value calculation map shown in FIG. 10 from the deviation (= T _{emp_mag_cl2} −T _{emp_mag_cl1} ) of the clutch margin temperatures T _{emp_mag_cl1} and T _{emp_mag_cl2} . As shown in the basic second clutch input rotational speed target value calculation map, the basic second clutch input rotational speed target value ω _{cl2i_base} ^* decreases as the second clutch margin temperature T _{emp_mag_cl2} decreases. It is set to approach the state.

In step S85, the lower limit value in step S84 is set to the second clutch output shaft rotational speed measured value _ωcl2o, and the basic second clutch input rotational speed target value _{ωcl2i_base} ^* is calculated by the same method.

In step S86, an inverter margin temperature T _{emp_mag_INV} that is a difference from the inverter temperature T _{emp_INV} to the upper limit temperature is calculated.
In step S87, when the inverter margin temperature T _{emp_mag_INV} is zero, the second clutch input rotational speed target value ω _cl2i ^* is the non-locking rotational speed (a value at which the inverter temperature does not decrease even if the rotational speed is further increased) ω _{UN_LOCK} Correction is performed so as to be as described above. Actually, the final second clutch input rotational speed target value ω _cl2i ^* is calculated based on the following conditions a) and b).
a) 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}
However, ω _{cl2i_hosei} is a second clutch input rotation speed correction value, and is calculated from the inverter margin temperature T _{emp_mag_INV} based on, for example, the map shown in FIG. As shown in this map, the second clutch input rotation speed correction value ω _{cl2i_hosei} has a characteristic that it increases as the inverter margin temperature T _{emp_mag_INV} decreases, that is, the motor rotation speed increases.

Next, a calculation method of the first clutch current command value I _cl1 ^* , which is the process performed in step S20, will be described based on FIG.

In step S201, the final first clutch torque capacity command value _{T cl1} ^*, clutch torque capacity previously acquired - first calculating a clutch stroke target value _{x SCL1} ^* using a map shown in FIG. 13 created by the stroke characteristic.

In step S202, the first clutch oil pressure command value _{P cl1} from the first clutch stroke target value _{x SCL1} ^* a first clutch stroke measurement value _{x SCL1} Prefecture, calculates. The details of calculating the first clutch hydraulic pressure command value _Pcl1 will be described later.

In step S203, the first clutch hydraulic pressure command value P _cl1 ^{* is} set so that the slope of the reaction force (hydraulic pressure) -stroke characteristic (the spring characteristic of the diaphragm spring) shown in FIG. Correct. Details of this correction will also be described later.

In step S204, the first clutch current command value _Icl1 ^* is calculated from the final hydraulic pressure command value _{Pcl1_com} using the map shown in FIG. 6B created based on the previously acquired characteristics.

Next, details of the calculation of the first clutch hydraulic pressure command value _Pcl1 in step S202 will be described. In the first embodiment, the two-degree-of-freedom control method shown in the first clutch stroke control system block diagram of FIG. 14 is adopted as in the second clutch rotation speed control described above.
First, from the first clutch stroke target value x _scl1 ^* , using a phase compensation filter consisting of a reverse system of a reference response transmission characteristic as shown in the following equation (19) and a controlled object transmission characteristic after hydraulic pressure correction described later. The feedforward hydraulic pressure command value _{Pcl1_FF} is calculated.
P _{cl1_FF} / x _sccl1 ^* = G _{cl1_FF} (s)
= (Ms ² + Cs + K _ref ) ω ² _ref / (s ² + 2ζ _ref ω _ref s + ω ² _ref ) (19)
In the above equation (19), C is the first clutch mechanism viscosity coefficient, K _ref is the spring constant to be controlled after hydraulic pressure correction, ζ _ref is the first clutch reference response damping coefficient, and ω _ref is the first clutch reference response. The natural frequency, M, is the clutch mass.

Then, the first clutch stroke target value _{x SCL1} ^*, calculates a first clutch stroke reference value _{x Scl1_ref} with a filter representing the nominal response transfer characteristic as shown in the following equation (20).
x _{sccl1_ref} / x _sccl1 ^* = G _{ref_cl1} (s)
= Ω ² _ref / s ² + 2ζ _ref ω _ref · s + ω ² _ref (20)
Then, the first clutch stroke reference value _{x Scl1_ref} and deviation _{x Scl1_err} of the first clutch stroke measurement value _{x SCL1,} calculates a feedback pressure command value _{P Cl1_FB} based on the following equation (21).
P _{cl1_FB} / x _{sccl1_err} = G _{FB_cl1} (s)
= (K _{Pgain_cl1} · s + K _{Igain_cl1} + K _{Dgain_cl1} · s ² ) / s (21)
However, K _{Pgain_cl1} is a proportional gain, K _{Igaincl_cl1} is an integral gain, and K _{Dgain_cl1} is a differential gain.

Finally, by adding the feedforward hydraulic pressure command value _{P Cl1_FF} and the feedback hydraulic pressure command value _{P Cl1_FB,} the first clutch oil pressure command value _{P cl1} ^*.

Next, details of the correction of the first clutch oil pressure command value P _cl1 ^* in step S203 will be described.
As this correction, in the first embodiment, any one of the following first correction method and second correction method is used.
First, the first correction method will be described. This correction is based on a map showing the relationship between the first clutch stroke measurement value _xscl1 and the first clutch hydraulic pressure estimated value _{Pcl1_est} created based on the characteristics shown in FIG. A first clutch hydraulic pressure estimated value P _{cl1_est} is _obtained from the first clutch stroke measurement value x _sccl1 . Further, a reaction force reference value P _{cl1_ref} calculated using the reference spring characteristic is obtained. Then, from the difference between the first clutch oil pressure estimate _{P Cl1_est} and the reaction force reference value _{P Cl1_ref} using equation (22) below, calculates the oil pressure correction value _{P cl1_hosei.}
P _{cl1_hosei} = P _{cl1_ref} −P _{cl1_est}
= K _ref · x _sccl1 -f _xsccl1-P (x _sccl1 ) (22)
However, f _xscl1-P () is a function indicating the hydraulic pressure-stroke characteristic.

Further, the hydraulic pressure correction value P _{cl1_hosei} may be calculated by _obtaining a spring constant Kp approximating the slope of the spring reaction force characteristic shown in FIG. 13 and using the following equation (23).
P _{cl1_hosei} = P _{cl1_ref} −P _{cl1_est}
= K _ref · x _sccl1 -K _p · x _sccl1 (23)
It should be noted that the correction value for each stroke may be calculated in advance using the above equation (23) and may be used as a map.

Based on the hydraulic pressure correction value P _{cl1_hosei} calculated as described above and the first clutch hydraulic pressure command value P _cl1 ^* , a final hydraulic pressure command value P _{cl1_com} is calculated based on the following equation (24).
^{_{P cl1_com = P cl1 * -P cl1_hosei}} ··· (24)
Next, the second correction method will be described.
First, as shown in FIG. 15, the slope of a straight line connecting the origins for each stroke (operating point) is converted into a spring constant and modeled (map).
The final hydraulic pressure command value P _{cl1_com} is calculated from the spring constant of the control object Kp thus obtained and the reference spring characteristic K _ref based on the following equation (25).
P _{cl1_com} = (Kp / K _ref ) P _cl1 ^* (25)
Next, the configuration for executing the inverter temperature suppression process and the clutch temperature suppression process in the integrated controller 17 will be briefly described with reference to the block diagrams of FIGS. 16 and 17.

As shown in FIG. 16, a clutch input rotational speed target value is calculated as a configuration for calculating the rotational speed control motor torque command value T _{m_FB_ON} and the rotational speed control engine torque command value _{Te_FB_ON} in executing the inverter temperature suppression process. Calculation means 161, motor torque command value calculation means 162, and engine torque command value calculation means 163 are provided.

The clutch input rotational speed target value calculating means 161 is configured to input the first clutch based on inputs from the second clutch output rotational speed sensor 7, the second clutch oil temperature sensor 16, the inverter temperature sensor 14, and the first clutch oil temperature sensor 15. An input rotational speed target value _ωcl1i ^* and a second clutch input rotational speed target value _ωcl2i ^* are calculated. That is, it is a part that executes the process of step S7.

The motor torque command value calculating means 162 calculates a motor torque command value T _{m_FB_ON} for rotation speed control based on the second clutch input rotation speed target value ω _cl2i ^* , and is a part for executing the process of step S14. . The rotational speed control motor torque command value _{Tm_FB_ON} is output to the motor controller 21.

The engine torque command value calculation means 163 calculates a rotation speed control engine torque command value _{Te_FB_ON} based on the first clutch input rotation speed target value _ωcl1i ^* , and is a part that executes the process of step S9. The engine speed command value _{Te_FB_ON} for rotation speed control is output to the engine controller 20.

Further, in executing the inverter temperature suppression process, as shown in FIG. 17, a clutch for calculating the second clutch torque capacity command value _{Tcl2_FB_ON} for rotation speed control and the first clutch torque capacity command value _{Tcl1_FB_ON} for rotation speed control. Torque capacity command means 171 is provided.

The clutch torque capacity command means 171 is a part that executes the processing of steps S10 and S15. As described above, the second clutch torque capacity command value for rotation speed control T _{cl2_FB_ON} is the vehicle state in the first embodiment. It is set to the same value as the target drive torque Td ^* calculated based on the driver operation amount. Also, the first clutch torque capacity command value _{Tcl1_FB_ON} for rotational speed control is set to the same value as the basic engine torque command value _{Te_base} ^* calculated based on the target drive torque Td ^* in step S6.

Next, the operation of the first embodiment will be described with reference to FIGS.
FIG. 18 shows an operation example of the first embodiment, and FIG. 19 corresponds to the prior art that does not execute the slip control of the second clutch CL2 based on the inverter temperature and the clutch temperature shown in FIG. 8 in the first embodiment. An operation example of the comparative example is shown. In both operation examples shown in FIGS. 18 and 19, the vehicle stops at a gradient at which a running resistance of 100 Nm is generated, and thereafter, the driving torque and the running resistance are matched by the driver's accelerator operation from the time t01 and t11 in the figure. The example which tried to hold | maintain a stop state (hill hold) is shown.

  Here, in the comparative example of FIG. 19, when the vehicle stops (t00), the engine Eng is stopped and the first clutch CL1 is released. The output torque of the motor generator MG rises and the clutch torque capacity of the second clutch CL2 increases from the time t01 when the driver performs the accelerator operation and starts to execute the hill hold. It is transmitted to LT and RT.

  At the time of this hill hold execution, torque is output from motor generator MG, but the vehicle is maintained in a stopped state, second clutch CL2 is locked, and the second clutch rotational speed is maintained at 0 rad / s.

  In such a locked state, the temperature of the inverter 8 rises as shown in the figure, and at the time indicated by t02 in the figure, torque limitation due to the inverter overtemperature is applied, and the output of the motor generator MG falls. For this reason, after that, after the time t03, the rotation speed of the second clutch CL2 decreases from 0 rad / s, and the vehicle rolls back.

On the other hand, in the operation example of the first embodiment shown in FIG. 18, when the vehicle is stopped (t00), the engine Eng is not stopped and is set to a rotation speed at which the stall does not occur based on the process of step S59. Further, second clutch input rotation speed target value ω _cl2i ^* , which is the rotation speed of motor generator MG, is also set based on the processing in step S87. From the time t00 to the time t11, the vehicle is stopped by the driver's brake operation, and at this time, both the clutches CL1 and CL2 are in a released state.

  Then, from the time t11 when the driver performs the accelerator operation and the hill hold is started, both clutch capacities are raised, and the vehicle is maintained in a stopped state with the torque output via the second clutch CL2. Since the motor generator MG is in the locked state from the start time t11 of this hill hold, the temperature of the inverter 8 starts to rise.

Then, when the inverter temperature T _{emp_INV} becomes _{equal to} or higher than the inverter temperature threshold T _{emp_INV_th} , the second clutch input rotation speed target value ω _cl2i ^* corresponding to the inverter margin temperature T _{emp_mag_INV} becoming 0 based on the process of step S87 ^. Is increased (execution of inverter temperature suppression processing). Accordingly, the rotational speed of motor generator MG is increased, the slip amount of second clutch CL2 is increased, and inverter temperature T _{emp_INV} is decreased. Therefore, after t12, motor generator MG is in an unlocked state.

On the other hand, the second clutch temperature T _{emp_cl2} starts to increase in order to cause the second clutch CL2 to slip from the time t12.

Thereafter, when the second clutch temperature T _{emp_cl2} rises and reaches the second clutch upper limit value T _{emp_cl2th} , the second clutch input rotation speed is based on the process of step S84, that is, according to the decrease in the second clutch margin temperature T _{emp_mag_cl2.} Target value _ωcl2i ^* is decreased (execution of clutch temperature suppression process). Therefore, at t13, the rotation speed of the motor generator MG is decreased, and the second clutch CL2 returns to the locked state without slipping. In the example shown in FIG. 18, the torque of motor generator MG is temporarily reduced to a negative level at which power is generated by the driving force of engine Eng.

Therefore, the temperature of the second clutch CL2 decreases, while the temperature of the inverter 8 starts increasing again. Thus, in the first embodiment, the inverter temperature T _{emp_INV} is lower than the upper limit value, does not exceed the inverter temperature threshold value T _{emp_INV_th} and reaches the upper limit value, and the second clutch temperature T _{emp_cl2} exceeds the upper limit value. There is no. Therefore, it is possible to suppress the occurrence of the problem that the inverter temperature rises and the output torque of the motor generator decreases to cause rollback.

As described above, the first embodiment has the following effects.
a) When driving torque is output by the motor generator MG at the time of hill hold or the like and the vehicle is stopped, if the inverter temperature T _{emp_INV} exceeds the inverter temperature threshold T _{emp_INV_th} , an inverter temperature suppression process is executed, While increasing the rotation speed of the generator MG, the second clutch CL2 was slipped to maintain the output rotation speed of the second clutch CL2 at 0 rad / s.

  Therefore, the heat generation of the inverter 8 can be suppressed, and the occurrence of rollback due to the heat generation can be suppressed.

b) When the inverter temperature suppression process is executed, when the second clutch temperature T _{emp_cl2} reaches the second clutch upper limit value T _{emp_cl2th} , the clutch temperature suppression process is executed to reduce the torque of the motor generator MG, The second clutch CL2 is returned to the engaged state.
Therefore, as in a) above, while suppressing the inverter temperature T _{emp_INV} , the second clutch CL2 to be slipped is suppressed from generating heat, and the durability of the second clutch CL2 is reduced, and rollback due to excessive slip is caused. Can be suppressed.

c) When executing the inverter temperature suppression process, the inverter upper limit temperature rotation speed ω _{TINV_MAX} , which is the rotation speed at which the inverter temperature does not become an _{overtemperature,} is calculated from the motor torque, and the second clutch input rotation speed target value ω _cl2i ^* is _calculated as the inverter upper limit temperature. The rotational speed is controlled to be _{equal to} or higher than ω _{TINV_MAX} .
Therefore, the inverter temperature _{T Emp_INV,} while keeping below the inverter temperature threshold value _{T Emp_INV_th,} it is possible to reduce the heating value of the second clutch CL2.

d) When stopping on the uphill road, the engine Eng is maintained in the driving state, the first clutch CL1 is engaged, and the driving force of the engine Eng is also output to the left and right driving wheels LT, RT. For this reason, at the time of hill hold, the output torque of the motor generator MG may be smaller than the conventional one, and the amount of heat generated when the locked state is established is reduced.
In addition, it is not necessary to start the engine at the time of the subsequent start, and all of the output torque of the motor generator MG can be used for acceleration of the vehicle. In addition, the output torque of the engine Eng can also be accelerated if necessary. It is possible to obtain a high acceleration feeling.

(Other examples)
Other embodiments will be described below. Since these other embodiments are modifications of the first embodiment, only the differences will be described, and the configuration common to the first embodiment or the other embodiments will be described. The description is omitted by giving a common reference numeral.

  In the second embodiment, the inverter temperature suppression process is different from the first embodiment. Therefore, first, the flow of the inverter temperature suppression process will be described based on the flowcharts of FIGS.

  In step S2001, it is determined whether or not the motor generator MG is in the locked state. If the motor generator MG is in the locked state, the process proceeds to step S2002. If the motor generator MG is in the unlocked state, one process is terminated.

In step S2002, it is determined whether or not the inverter temperature T _{emp_INV} is _{equal to} or higher than a preset inverter temperature threshold T _{emp_INV_th} . If it exceeds, the process proceeds to step S2003, and if not, the process proceeds to step S2015.

In step S2003, after the inverter temperature T _{emp_INV} exceeds the inverter temperature threshold value T _{emp_INV_th} in step S2002, it is further determined whether or not a preset lock avoidance operation necessity determination time tth has elapsed. In step S2004, if the time has not elapsed, one process is terminated.

The inverter temperature threshold T _{emp_INV_th} used in step S2002 is set lower than the upper limit temperature of the inverter 8. That is, when the heat generation characteristic of the inverter 8 has a characteristic as shown in FIG. 22 and has a time constant X that rises to the upper limit value, the temperature ΔTj at the time before the lock avoidance operation necessity determination time tth is expressed as the inverter temperature threshold value. T _{emp_INV_th} is set.

  In step S2004, a command to decrease the torque capacity of the second clutch CL2 is output, and a command to increase the output of the motor torque output by the motor generator MG is issued, and the process proceeds to step S2005.

  In step S2005, it is determined whether or not the motor torque output command value exceeds a preset engine start determination value. If it exceeds, the process proceeds to step S2012. If not, the process proceeds to step S2006. The engine start determination value is set to a value slightly smaller than the value obtained by subtracting the torque required for engine start from the maximum output of motor torque, and the engine can be started while maintaining the hill hold state. It is a limit value.

  In step S2006, it is determined whether or not the rotation of the motor generator MG has been detected. When rotation is detected, the process proceeds to step S2007. When rotation is not detected, the process returns to step S2004, and further, the torque capacity source of the second clutch CL2; Increase motor torque.

In step S2007, the torque capacity of the second clutch CL2 is maintained, the rotational speed of the motor generator MG is controlled to the unlocked target rotational speed, and the process proceeds to step S2008.
A method of calculating the target input rotational speed ω _mt that is the rotational speed of the motor generator MG at this time will be described.
This target input rotational speed ω _mt is a clutch temperature rise preventing rotational speed ω _{cl_temp} that is a rotational speed capable of preventing the temperature increase of the second clutch CL2 obtained from the torque capacity of the second clutch CL2 and the output rotational speed, and the motor is not locked. It is set according to the rotational speed ω _{m_LOCKOFF} .

Here, when ω _{cl_temp} ≧ ω _{m_LOCKOFF} , ω _mt ≧ ω _{cl_temp} is set.
On the other _hand, ω cl_temp <For _ω m_LOCKOFF, according to the second clutch temperature _{T emp_cl2,} the case of less than the second clutch temperature _{T Emp_cl2} is preset clutch over-temperature threshold value _{T emp_th,} and _{ω mt} ≧ ω cl_temp. When the second clutch temperature T _{emp_cl2} is _{equal to} or higher than the _preset clutch overtemperature threshold T _{emp_th} , ω _mt ≦ ω _{cl_temp} is set.

In step S2008, the torque capacity of the second clutch CL2 is variably controlled according to the required drive torque, and the process proceeds to step S2009.
In step S2009, as in step S2005, it is determined whether or not the motor torque output command value exceeds the engine start determination value. If it exceeds, the process proceeds to step S2012, and if not, the process proceeds to step S2010.

  In step S2010, it is determined whether or not the output rotation exceeds the motor rotation speed Nm. If it exceeds, the process proceeds to step S2011. If not, the process returns to step S2008. In step S2011, the inverter temperature suppression process is terminated, the normal control is resumed, and one process is terminated.

In step S2012, the motor rotation speed command value (second clutch input rotation speed target value _ωcl2i ^* ) is increased to a rotation speed at which the engine can be started, an engine start request command is output, and the process proceeds to step S2013.

  In step S2013, it is determined whether the engine start is completed. If completed, the process proceeds to step S2014. If not completed, the determination in step S2013 is repeated. In step S2014, the inverter temperature suppression process is terminated, the normal control is resumed, and one process is terminated.

In step S2015, when the second clutch temperature T _{emp_cl2 of} the second clutch CL2 exceeds the clutch temperature threshold value, the process proceeds to step S2016, and if it is less than the clutch temperature threshold value, one process is terminated.

  In step S2016, the clutch capacity of the second clutch CL2 is increased and the motor torque is reduced.

  In the second embodiment, in the determination of the first clutch control mode in step S4 described in the first embodiment, when stopping, the engine Eng is stopped regardless of whether it is an uphill road or not, unlike the first embodiment. The first clutch CL1 is released and the EV mode is controlled.

Next, the operation of the second embodiment will be described based on the time chart of FIG.
In the figure, it is assumed that hill hold is started at time t00 and the temperature of the inverter 8 starts to rise. Immediately before t21, the inverter temperature T _{emp_INV} becomes _{equal to} or higher than the inverter temperature threshold T _{emp_INV_th} , and the lock avoidance operation necessity determination time tth has elapsed (steps S2001 → S2002 → S2003), and at the time t21, the step S2004 is performed. Based on this process, the motor torque is increased and the torque capacity of the second clutch CL2 is decreased. As a result, the torque output and the clutch transmission torque (clutch capacity) gradually approach each other.

  As a result, the clutch capacity is held at time t22 when the motor rotation speed Nm occurs (steps S2006 → S2007). Note that the transmission torque at this time is X [Nm], and at this time, the drive shaft torque is also X [Nm].

Furthermore, by the process of step S2007, the motor generator MG is raised toward the target input rotational speed ω _mt by the rotational speed control. Then, after time t23 when the target input rotational speed ω _{mt is} reached, the clutch capacity is controlled according to the required driving force based on the processing in step S2008 to generate the driving force.

  Thus, when motor generator MG rotates, heat generation of inverter 8 is suppressed, and a temperature rise is suppressed.

Furthermore, in the example shown in this time chart, for example, when the driving force is generated according to the required driving force based on the processing in step S2008 after the time point t23 due to a large road surface inclination or the like, t24 At this point, the motor torque output command value exceeds the engine start determination value. In this case, since the engine Eng cannot be started if the motor torque further increases, the motor rotation speed Nm is increased to an engine startable rotation speed (for example, 1000 rpm) based on the processing in step S2012.
As a result, the engine Eng is started (t25), and thereafter, the engine torque is used as the driving force.

  Therefore, there is no problem that the motor torque becomes too high and the engine cannot be started, and the motor generator MG alone can suppress the occurrence of rollback even when the road surface slope is difficult to hill hold. And at the time of start, it is possible to start smoothly according to the driver's request without causing rollback.

  Next, a process for increasing the responsiveness as necessary when the torque capacity of the second clutch CL2 is reduced in step S2004 will be described based on the time chart of FIG.

  Also in this time chart, it is assumed that the inverter temperature suppression process is started at time t31. Thereby, similarly to the time chart of FIG. 23, the motor torque is increased until the motor generator rotation occurs. At this time, if the torque capacity Tt at the time t31 and the motor torque are more than the set value, the torque capacity is reduced to near the motor torque (for example, about motor torque +10 Nm). (T32), the torque capacity is gradually reduced until a slip (increase in the motor speed) is detected (t33).

  Therefore, it is possible to shorten the time until motor generator MG is in the non-fixed state (slip state), and to suppress the temperature rise of inverter 8 during that time.

Next, an operation example when the temperature of the second clutch CL2 rises will be described based on the time chart of FIG.
In this case, when the vehicle stops at time t00, the engine Eng is stopped and both the clutches CL1 and CL2 are released.

  Next, at time t41, the driver performs an accelerator operation, the second clutch CL2 is engaged, and the driver performs an operation for forming a hill hold state. As a result, when the second clutch temperature rises and exceeds the clutch temperature threshold, the clutch capacity of the second clutch CL2 is increased and the motor torque is reduced (at time t42) based on the processing in step S2016. .

  Therefore, the temperature of the second clutch CL2 is lowered.

  As mentioned above, although the control apparatus of the electric vehicle of this invention has been demonstrated based on Example 1 and Example 2, it is not restricted to these Examples about a concrete structure, Each of Claims Design changes and additions are permitted without departing from the scope of the claimed invention.

  For example, in the first and second embodiments, the automatic transmission AT is interposed between the motor generator MG and the drive wheels (LT, RT). However, such a transmission may not be interposed. . Alternatively, when a transmission is interposed, a manual transmission, a mechanical automatic transmission, or the like may be used.

  In the first and second embodiments, the motor generator MG capable of regeneration is shown as the motor. However, the present invention is not limited to this, and a motor capable of only power running may be used.

  Further, in the first and second embodiments, the first clutch CL1 is provided and the drive transmission path between the engine Eng and the motor generator MG can be connected / disconnected, but the first clutch CL1 is not provided. The engine Eng and the motor generator MG may be always coupled.

  Moreover, in Example 1, 2, although the hill hold time was shown as an operation example, it is not limited to this, An inverter temperature suppression process and a clutch temperature suppression process are applied also when performing low-speed climbing etc. be able to.

  In the first and second embodiments, the FR hybrid vehicle is shown, but it can also be applied to a front-wheel drive or four-wheel drive type hybrid vehicle. Alternatively, in the first and second embodiments, a so-called hybrid vehicle including the engine Eng and the motor generator MG as the drive source is shown, but the present invention can also be applied to an electric vehicle including only the motor or the motor generator as the drive source. .

6 Second clutch input rotation speed sensor (vehicle state detection means)
7 Second clutch output rotational speed sensor (vehicle state detection means)
8 Inverter 9 Battery (Power supply)
10 Accelerator sensor (vehicle state detection means)
11 Engine speed sensor (vehicle state detection means)
12 Transmission oil temperature sensor (vehicle state detection means)
13 Stroke sensor (vehicle state detection means)
14 Inverter temperature sensor (Inverter temperature detection means)
15 1st clutch oil temperature sensor (vehicle state detection means)
16 Second clutch oil temperature sensor (clutch temperature detecting means)
17 Integrated controller (control means)
30 Road surface inclination angle sensor (vehicle state detection means)
CL2 Second clutch (clutch)
LT Left drive wheel RT Right drive wheel MG Motor generator (motor)
T _{emp_cl2} Second clutch temperature T _{emp_INV} Inverter temperature T _{emp_INV_th} Inverter temperature threshold T _{emp_th} Clutch over temperature threshold

Claims (2)

A clutch provided in the middle of the driving force transmission path between the motor and the driving wheel, and capable of disconnecting the motor side and the driving wheel side;
An inverter that performs power conversion between the motor and a power source;
Vehicle state detection means for detecting the state of the vehicle, including clutch temperature detection means for detecting the temperature of the clutch and inverter temperature detection means for detecting the temperature of the inverter;
Control means for controlling the driving force of the motor based on the vehicle state detected by the vehicle state detection means, and for controlling the engagement state of the clutch;
An electric vehicle control device comprising:
The control means is configured such that an inverter temperature detected by the inverter temperature detection means is a preset inverter temperature threshold value in a state where the motor torque is transmitted to the drive wheel side via the clutch by driving the motor. Is exceeded, an inverter temperature suppression process is performed to increase the slip amount of the clutch by increasing the motor rotation speed, while the clutch temperature detected by the clutch temperature detection means is a preset clutch temperature. When the temperature threshold value is exceeded, the control apparatus for the electric vehicle is characterized in that a clutch temperature suppression process is executed to reduce the slip amount by reducing the motor rotation speed.   The control means calculates an inverter upper limit temperature rotation speed, which is a rotation speed at which the inverter temperature does not become an overtemperature, from the motor torque during the execution of the inverter temperature suppression process, and calculates the clutch input rotation speed target value as the inverter upper limit temperature rotation speed. The control apparatus for an electric vehicle according to claim 1, wherein the control is performed to be more than a few.

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