JP6229397B2 - Control device for hybrid vehicle - Google Patents

Description

  The present invention relates to a control apparatus for a hybrid vehicle equipped with slip fastening control means for slip fastening a friction fastening element at a downstream position of a motor and traction control means for suppressing wheel spin of a drive wheel.

  Conventionally, in the WSC mode in which the clutch interposed between the motor and the drive wheel is slip-engaged by motor speed control, the target motor speed is set to the upper limit speed obtained by adding a predetermined slip amount to the vehicle speed. A control device for a hybrid vehicle is known (see, for example, Patent Document 1).

JP 2012-86705 A

  However, in the conventional hybrid vehicle control device, the target motor rotational speed is set to the upper limit rotational speed that increases following the increase in the vehicle body speed. For this reason, when traction control (TCS control) intervenes during WSC mode on extremely low μ roads such as icing roads, the target motor speed> actual motor speed, and the motor will try to increase torque by increasing torque. . As a result, there is a problem that if TCS control intervenes during the WSC mode, excessive torque (TCS command torque <actual torque) will occur. On the other hand, if the upper limit rotational speed is set to a low rotational speed so as not to cause excessive torque, there is a problem that the engine may stall.

  The present invention has been made paying attention to the above problem, and provides a hybrid vehicle control device that can achieve excessive torque prevention and engine stall prevention when traction control intervenes during slip engagement control of a friction engagement element. The purpose is to provide.

In order to achieve the above object, the present invention has an engine, a motor, a friction fastening element, and a drive wheel in a drive system.
Slip fastening control means for controlling the rotational speed of the motor to match the target motor rotational speed that secures the slip amount of the frictional engagement element, and slip-engaging the frictional engagement element with a capacity corresponding to the required driving force Is provided.
In this hybrid vehicle control device, when it is detected that wheel spin has occurred in the drive wheel, traction control means for performing traction control to reduce drive torque transmitted from the drive wheel to the road surface and to reduce the amount of wheel spin. Is provided.
When the traction control intervenes during the slip engagement control of the friction engagement element, the slip engagement control means sets the target motor rotation speed to a lower limit rotation speed determined by system requirements while setting the motor to motor rotation speed control. A motor lower limit rotational speed setting unit is included.
Then, the motor lower limit rotational speed setting unit adjusts and sets the lower limit rotational speed determined from the system request to a rotational speed at which the required driving force by the traction control can be output.

Therefore, when the traction control intervenes during the slip engagement control of the friction engagement element, the target motor rotation speed is set to the lower limit rotation speed determined from the system requirements while the motor is set to the motor rotation speed control.
That is, the lower limit rotational speed set as the target motor rotational speed is a rotational speed that keeps the actual motor rotational speed above this rotational speed. For this reason, if traction control intervenes during slip engagement control of the friction engagement element, the target motor rotation speed ≤ the actual motor rotation speed, and the motor does not need to increase its rotation by generating torque, and an extremely low μ road such as an icing road In this case, excessive torque is prevented.
On the other hand, the lower limit rotational speed set as the target motor rotational speed is a rotational speed that suppresses a decrease in the actual motor rotational speed from this rotational speed. For this reason, even if the motor rotational speed is lowered to a rotational speed lower than the system-required lower rotational speed, the lower rotational speed is supported and engine stall is prevented.
As a result, excessive torque prevention and engine stall prevention can be achieved when traction control intervenes during slip engagement control of the friction engagement element.

1 is an overall system diagram illustrating an FF hybrid vehicle to which a control device according to a first embodiment is applied. It is a block diagram which shows the control system system which comprises the control apparatus of Example 1. FIG. 6 is a flowchart illustrating a flow of target drive force / target rotation number calculation processing by a target drive force calculation unit of the hybrid control module according to the first embodiment. 3 is an overall flowchart illustrating a flow of torque distribution calculation processing by a torque distribution calculation unit of the hybrid control module according to the first embodiment. It is a flowchart which shows the flow of the target ENG torque calculation process among torque distribution calculation processes. It is a flowchart which shows the flow of the target MG torque calculation process among torque distribution calculation processes. It is a flowchart which shows the flow of MG lower limit torque calculation processing among torque distribution calculation processing. It is a flowchart which shows the flow of the target MG rotation speed calculation process among torque distribution calculation processes. It is a flowchart which shows the flow of the target CL2 torque calculation process among torque distribution calculation processes. It is a flowchart 1 which shows the flow of a CL2 excessive slip prevention process among the processes accompanying a torque distribution calculation process. It is a flowchart 2 which shows the flow of a CL2 excessive slip prevention process among the processes accompanying a torque distribution calculation process. It is the flowchart 1 which shows the flow of the ENG torque feedback process by WSC at the time of cryogenic temperature among the processes accompanying a torque distribution calculation process. It is the flowchart 2 which shows the flow of the ENG torque feedback process by WSC at the time of cryogenic temperature among the processes accompanying a torque distribution calculation process. When TCS control is intervened during WSC mode, the target MG speed, actual MG speed, wheel speed, vehicle speed, TCS torque down characteristics (a) and TCS of the comparative example when TCS control is not performed 6 is a time chart showing characteristics (b) of target MG rotation speed, actual MG rotation speed, wheel speed, vehicle body speed, TCS torque down, and ENG + MG torque when corresponding control is performed. MG upper limit torque, actual MG torque, MG lower limit torque, target MG rotation speed, ENG rotation speed, WSC target rotation speed, wheel speed, when TCS control is intervened during WSC mode It is a time chart which shows each characteristic of a vehicle body speed and a TCS operation flag.

  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.
The configuration of the FF hybrid vehicle (an example of a hybrid vehicle) to which the control device of the first embodiment is applied is referred to as “overall system configuration”, “control system block configuration”, “target driving force calculation unit configuration and torque distribution calculation unit configuration”. ”,“ Detailed configuration of torque distribution calculation process ”,“ CL2 excessive slip prevention process configuration ”, and“ ENG torque FB process configuration by WSC at cryogenic temperature ”.

[Overall system configuration]
FIG. 1 shows an overall system of an FF hybrid vehicle. Hereinafter, the overall system configuration of the FF hybrid vehicle will be described with reference to FIG.

  As shown in FIG. 1, the drive system of the FF hybrid vehicle includes a starter motor 1, a horizontally mounted engine 2, a first clutch 3 (abbreviated as “CL1”), a motor / generator 4, and a second clutch 5 ( An abbreviation “CL2”) and a belt-type continuously variable transmission 6 (abbreviation “CVT”). The output shaft of the belt type continuously variable transmission 6 is drivingly connected to the left and right front wheels 10R and 10L via a final reduction gear train 7, a differential gear 8, and left and right drive shafts 9R and 9L. The left and right rear wheels 11R and 11L are driven wheels.

  The starter motor 1 is a cranking motor that has a gear that meshes with an engine starting gear provided on a crankshaft of the horizontally mounted engine 2 and that rotates the crankshaft when the engine is started.

  The horizontal engine 2 is an engine disposed in the front room with the crankshaft direction as the vehicle width direction, and includes an electric water pump 12 and a crankshaft rotation sensor 13 that detects reverse rotation of the horizontal engine 2.

  The first clutch 3 is a normally open dry multi-plate friction clutch that is hydraulically interposed between the horizontal engine 2 and the motor / generator 4, and is fully engaged / slip engaged / released by the first clutch oil pressure. Is controlled.

  The motor / generator 4 is a three-phase AC permanent magnet type synchronous motor connected to the transverse engine 2 through a first clutch 3. The motor / generator 4 uses a high-power battery 21 described later as a power source, and an inverter 26 that converts direct current into three-phase alternating current during power running and converts three-phase alternating current into direct current during regeneration is connected to the stator coil. Connected through.

  The second clutch 5 is a wet-type multi-plate friction clutch by hydraulic operation that is interposed between the motor / generator 4 and the left and right front wheels 10R and 10L that are driving wheels. Slip fastening / release is controlled. The second clutch 5 of the first embodiment uses the forward clutch 5a and the reverse brake 5b provided in the forward / reverse switching mechanism of the belt-type continuously variable transmission 6 using planetary gears. That is, the forward clutch 5 a is the second clutch 5 during forward travel, and the reverse brake 5 b is the second clutch 5 during reverse travel.

  The belt-type continuously variable transmission 6 is a transmission that obtains a continuously variable transmission ratio by changing the belt winding diameter by the transmission hydraulic pressure to the primary oil chamber and the secondary oil chamber. The belt type continuously variable transmission 6 includes a main oil pump 14 (mechanical drive), a sub oil pump 15 (motor drive), and a line pressure PL generated by adjusting pump discharge pressure from the main oil pump 14. And a control valve unit (not shown) that generates the first and second clutch hydraulic pressures and the transmission hydraulic pressure with the pressure as the original pressure. The main oil pump 14 is rotationally driven by a motor shaft (= transmission input shaft) of the motor / generator 4. The sub oil pump 15 is mainly used as an auxiliary pump for producing lubricating cooling oil.

  The first clutch 3, the motor / generator 4 and the second clutch 5 constitute a one-motor / two-clutch drive system. The main drive modes of this drive system are “EV mode”, “HEV mode” and “WSC mode”. Is included. The “EV mode” is an electric vehicle mode in which the first clutch 3 is disengaged and the second clutch 5 is engaged and only the motor / generator 4 is used as a drive source. Driving in the “EV mode” is referred to as “EV driving”. . The “HEV mode” is a hybrid vehicle mode in which both the clutches 3 and 5 are engaged and the horizontal engine 2 and the motor / generator 4 are used as driving sources, and traveling in the “HEV mode” is referred to as “HEV traveling”. The “WSC mode” is a CL2 slip engagement mode in which the motor / generator 4 is controlled to rotate the motor and the second clutch 5 is slip-engaged with a capacity corresponding to the required driving force. This "WSC mode" does not have a rotation differential absorption joint like a torque converter in the drive system, so in the starting area after stopping in the "HEV mode", etc. It is selected to absorb the rotational difference between the left and right front wheels 10L, 10R by CL2 slip engagement.

  The regenerative cooperative brake unit 16 shown in FIG. 1 is a device that controls the total braking torque in accordance with the regenerative operation in principle when the brake is operated. The regenerative cooperative brake unit 16 includes a brake pedal, a negative pressure booster that uses the intake negative pressure of the horizontally placed engine 2, and a master cylinder. Then, during the brake operation, cooperative control for the regenerative / hydraulic pressure is performed such that the amount of subtraction of the regenerative braking force from the required braking force based on the pedal operation amount is shared by the hydraulic braking force.

  As shown in FIG. 1, the power system of the FF hybrid vehicle includes a high-power battery 21 as a motor / generator power source and a 12V battery 22 as a 12V system load power source.

  The high-power battery 21 is a secondary battery mounted as a power source for the motor / generator 4. For example, a lithium ion battery in which a cell module constituted by a large number of cells is set in a battery pack case is used. The high-power battery 21 has a built-in junction box in which relay circuits for supplying / cutting off / distributing high-power are integrated, and further includes a cooling fan unit 24 having a battery cooling function, a battery charging capacity (battery SOC) and a battery. And a lithium battery controller 86 for monitoring the temperature.

  The high-power battery 21 and the motor / generator 4 are connected via a DC harness 25, an inverter 26, and an AC harness 27. The inverter 26 is provided with a motor controller 83 that performs power running / regenerative control. That is, the inverter 26 converts a direct current from the DC harness 25 into a three-phase alternating current to the AC harness 27 during power running for driving the motor / generator 4 by discharging the high-power battery 21. Further, the three-phase alternating current from the AC harness 27 is converted into a direct current to the DC harness 25 during regeneration in which the high-power battery 21 is charged by power generation by the motor / generator 4.

  The 12V battery 22 is a secondary battery mounted as a power source for a 12V system load that is an auxiliary machine, and for example, a lead battery mounted in an engine car or the like is used. The high voltage battery 21 and the 12V battery 22 are connected via a DC branch harness 25 ′, a DC / DC converter 37, and a battery harness 38. The DC / DC converter 37 converts a voltage of several hundred volts from the high-power battery 21 into 12V, and the charge amount of the 12V battery 22 is controlled by controlling the DC / DC converter 37 by the hybrid control module 81. The configuration is to be managed.

  As shown in FIG. 1, the control system of the FF hybrid vehicle includes a hybrid control module 81 (abbreviation: “HCM”) as an integrated control unit that has a function of appropriately managing energy consumption of the entire vehicle. Control means connected to the hybrid control module 81 include an engine control module 82 (abbreviation: “ECM”), a motor controller 83 (abbreviation: “MC”), and a CVT control unit 84 (abbreviation: “CVTCU”). VDC / TCS control unit 85 (abbreviation: “VDC / TCSCU”) and lithium battery controller 86 (abbreviation: “LBC”). These control means including the hybrid control module 81 are connected via a CAN communication line 90 (CAN is an abbreviation for “Controller Area Network”) so that bidirectional information can be exchanged.

  The hybrid control module 81 performs various controls based on input information from each control means, an ignition switch 91, an accelerator opening sensor 92, a vehicle speed sensor 93, and the like. The engine control module 82 performs fuel injection control, ignition control, fuel cut control, and the like of the horizontally placed engine 2. The motor controller 83 performs power running control, regeneration control, and the like of the motor generator 4 by the inverter 26. The CVT control unit 84 performs engagement hydraulic pressure control of the first clutch 3, engagement hydraulic pressure control of the second clutch 5, shift hydraulic pressure control of the belt type continuously variable transmission 6, and the like. The lithium battery controller 86 manages the battery SOC, battery temperature, and the like of the high-power battery 21.

  The VDC / TCS control unit 85 is a control means that exhibits a VDC function and a TCS function that improve vehicle stability by brake control and engine / motor output control. The VDC function is a function that suppresses the side slip by brake control and engine / motor output control independent of each wheel when the sensor detects the side slip state of the vehicle. When the wheel speed sensor detects that wheel spin has occurred on the left and right front wheels 10L, 10R, which are driving wheels, the TCS function increases the brake fluid pressure of the wheel spin generation wheel and controls engine / motor output to decrease. This is a function to reduce the wheel spin amount.

[Control system block configuration]
FIG. 2 shows a control system system. Hereinafter, the block configuration of the control system system will be described with reference to FIG.

  As shown in FIG. 2, the control system system includes a hybrid control module 81, an engine control module 82, a motor controller 83, a CVT control unit 84, a VDC / TCS control unit 85, a lithium battery controller 86, It has.

  The hybrid control module 81 includes a target driving force calculation unit 81a and a torque distribution calculation unit 81b. The target driving force calculation unit 81a calculates the target driving force and the target rotational speed, outputs the target driving force to the torque distribution calculation unit 81b, and outputs the target rotational speed to the CVT control unit 84. In the torque distribution calculation unit 81b, the target driving force is input from the target driving force calculation unit 81a, and various value calculation processes described later are performed.

  The engine control module 82 receives the ENG torque command value calculated by the torque distribution calculation unit 81b, and outputs a control command to the fuel injection actuator of the horizontally mounted engine 2 so that the ENG torque becomes the command value. .

  The motor controller 83 inputs the MG torque command value (or MG rotation speed command value), the MG upper limit torque, and the MG lower limit torque calculated by the torque distribution calculation unit 81b, so that these command values and torque are satisfied. A control command is output to the inverter 26 of the motor / generator 4.

  The CVT control unit 84 inputs the target rotational speed calculated by the target driving force calculation unit 81a, determines the gear ratio by the target gear ratio calculation unit 84a, and becomes the determined gear ratio (= transmission ratio). A primary hydraulic control command and a secondary hydraulic control command are output to the control valve of the belt type continuously variable transmission 6. Further, the CL2 torque command value calculated by the torque distribution calculation unit 81b is input, and the CL1 hydraulic control command is output to the control valve of the second clutch 5 so that the CL2 torque becomes the command value.

  The VDC / TCS control unit 85 outputs a torque down request to the hybrid control module 81 during TCS control. Further, the estimated torque value calculated by the torque distribution calculation unit 81b is input, and an output torque reduction command and a brake fluid pressure increase command to the engine / motor are output so that the drive torque becomes the estimated value.

  The lithium battery controller 86 outputs information on the battery SOC and the power limit value to the hybrid control module 81 during TCS control.

[Target driving force calculation unit configuration and torque distribution calculation unit configuration]
FIG. 3 shows a flow of target driving force / target rotation number calculation processing by the target driving force calculation unit, and FIG. 4 shows a flow of torque distribution calculation processing by the torque distribution calculation unit. Hereinafter, based on FIG.3 and FIG.4, each step showing a target drive force calculating part structure and a torque distribution calculating part structure is demonstrated.

  The target driving force / target rotational speed calculation process by the target driving force calculation unit 81a will be described. In step S1, it is determined whether or not a TCS operation is present. If YES (TCS operation is present), the process proceeds to step S3. If NO (TCS operation is not present), the process proceeds to step S2. In step S2, following the determination that the TCS operation is not performed in step S1, the target driving force is set to a driver-requested driving force calculated based on the accelerator opening, and the process proceeds to step S4. In step S3, following the determination in step S1 that the TCS operation is present, the target driving force is calculated as a driver-requested driving force calculated based on the accelerator opening and a TCS-requested torque-down driving force calculated based on the wheel spin amount. Of these, the smaller driving force is selected, and the process proceeds to step S4. In step S4, following the calculation of the target driving force in step S2 or step S3, the target rotational speed of the motor / generator 4 that obtains the target driving force is calculated and output to the CVT control unit 84 as information for determining the gear ratio. Go to the end.

  The torque distribution calculation process by the torque distribution calculation unit 81b will be described. In step S5, the target ENG torque is calculated (FIG. 5), and the process proceeds to step S6. In step S6, the target MG torque is calculated (FIG. 6), and the process proceeds to step S7. In step S7, the MG lower limit torque is calculated (FIG. 7), and the process proceeds to step S8. In step S8, the target MG speed is calculated (FIG. 8), and the process proceeds to step S9. In step S9, the target CL2 torque is calculated (FIG. 9), and the process proceeds to the end.

[Detailed configuration of torque distribution calculation processing]
5 shows the flow of the target ENG torque calculation process, FIG. 6 shows the flow of the target MG torque calculation process, FIG. 7 shows the flow of the MG lower limit torque calculation process, and FIG. 8 shows the target MG rotation speed. The flow of the calculation process is shown, and FIG. 9 shows the flow of the target CL2 torque calculation process. Hereinafter, each step representing the detailed configuration of the torque distribution calculation process will be described with reference to FIGS.

The target ENG torque is calculated according to the flowchart of FIG. That is, in step S51,
Target ENG torque = target driving force + power generation torque + correction (inertia, etc.)
This is calculated using the following formula.

The target MG torque is calculated by the flowchart shown in FIG. In step S61, it is determined whether or not the motor / generator 4 is performing torque control. If YES (during motor torque control), the process proceeds to step S63. If NO (during motor rotation speed control), the process proceeds to step S62. In step S62, following the determination that the motor rotation speed control is being performed in step S61, it is determined whether or not TCS control is being performed. If YES (TCS control is in progress), the process proceeds to step S63. If NO (TCS is not being controlled), the process proceeds to the end. In step S63, following the determination that motor torque control is being performed in step S61 or TCS control is being performed in step S62, the target MG torque is
Calculate with the formula of target MG torque = target driving force (input torque equivalent) −ENG torque estimated value, and proceed to the end.

The MG lower limit torque is calculated by the flowchart shown in FIG. In step S71, it is determined whether or not the motor / generator 4 is under rotation speed control. If YES (during motor rotation speed control), the process proceeds to step S72. If NO (during motor torque control), the process proceeds to the end. In step S72, following the determination that the motor rotation speed control is being performed in step S71, it is determined whether or not TCS control is being performed. If YES (during TCS control), the process proceeds to step S74. If NO (during TCS non-control), the process proceeds to step S73. In step S73, following the determination that TCS is not being controlled in step S72, the MG lower limit torque is calculated based on the maximum value determined by the limit of the input power of the high-power battery 21 and the battery SOC, and the process proceeds to the end. In step S74, following the determination that TCS control is being performed in step S72, the MG lower limit torque is set to the target MG torque (torque calculated in step S63 in FIG. 6), and the process proceeds to the end.
Here, the torque calculated in step S74 is set to the torque equivalent to the required torque in TCS control, that is, the torque obtained by subtracting the estimated engine torque value from the TCS required torque down driving force (= target MG torque during TCS control). (Motor lower limit torque setting section).

The target MG rotation speed is calculated by the flowchart shown in FIG. In step S81, it is determined whether or not the motor / generator 4 is under rotation speed control (CL2 is slipping). If YES (during motor rotation speed control), the process proceeds to step S82. If NO (during motor torque control), the process proceeds to the end. In step S82, it is determined whether or not TCS control is being performed following the determination that motor speed control is being performed in step S81. If YES (TCS controlled), the process proceeds to step S84. If NO (TCS not controlled), the process proceeds to step S83. In step S83, following the determination that TCS is not being controlled in step S82, the target MG speed is set to
Calculate using the formula of target MG speed = transmission output speed (OUTREV) × gear ratio + CL2 slip amount and proceed to the end. In step S84, following the determination that TCS control is being performed in step S82, the target MG rotational speed is set to the lower limit rotational speed (= the lower limit value of the target MG rotational speed) determined from the system request, and the process proceeds to the end.

Here, the target MG rotation speed calculated in step S83 will be described in detail.
・ Idle speed ・ CL1 damper protection speed (resonance frequency)
・ Lowest engine stall speed ・ CL2 slip maintaining speed (OUTREV x gear ratio + CL2 slip)
Of the four rotation speeds, the maximum rotation speed is used.
The lower limit rotational speed calculated in step S84 (motor lower limit rotational speed setting unit) will be described in detail.
・ Idle speed ・ CL1 damper protection speed (resonance frequency)
・ An engine stall lower limit rotational speed ・ Rotational speed at which the required driving force can be obtained by TCS control Among the above four rotational speeds, the rotational speed is higher than the maximum rotational speed.
Note that the rotational speed at which the required driving force by the TCS control can be output is set to a higher rotational speed (variable value) as the required driving force is larger, and is set to a higher rotational speed (variable value) as the battery output is restricted. That is, the lower limit rotational speed may be in the rotational speed range between the actual MG rotational speed and the target MG rotational speed lower limit. However, since the second clutch 5 generates more heat as the differential rotation increases, an upper limit is provided so as not to cause excessive slip.

The target CL2 torque is calculated by the flowchart shown in FIG. In step S91, it is determined whether or not the motor / generator 4 is under torque control (during CL2 L / U). If YES (during motor torque control), the process proceeds to step S93. If NO (during motor speed control), the process proceeds to step S92. In step S92, following the determination that the motor rotation speed control is being performed in step S91, the target CL2 torque is advanced to the end as the target drive torque. In step S93, following the determination that the motor torque control is being performed in step S91, the target CL2 torque is set to
Calculate the target CL2 torque = target drive force (input torque equivalent) + L / U margin and proceed to the end.

[CL2 overslip prevention treatment configuration]
10 and 11 show the flow of the CL2 overslip prevention process. Hereinafter, based on FIG.10 and FIG.11, each step showing CL2 excessive slip prevention process structure is demonstrated.
By preventing the target value of the engine torque F / B at the time of engine boost from being referred to the target MG speed (= lower limit speed) that has been reduced due to TCS control intervention, unnecessary engine speed up is prevented. Torque down is not activated for. That is, when the second clutch 5 has overslipted, the process proceeds from step S101 to step S102 in FIG. 10, and in step S102, the ENG torque down amount (= CL2 slip amount × gain) is obtained, and the horizontal engine 2 is set. Torque down to prevent CL2 overslip. Then, during the TCS control, the process proceeds from step S103 to step S105 in FIG. 11. In step S105, the CL2 slip amount is set to a target rotation speed equivalent value at the time of TCS-OFF (= actual MG rotation speed−target MG rotation speed). And the lower limit rotational speed decreased due to the TCS control intervention is not referred to. During TCS non-control, the process proceeds from step S103 to step S104 in FIG. 11, and in step S104, the CL2 slip amount is set as the target MG rotation speed.

[Configuration of ENG torque FB processing by WSC at cryogenic temperature]
12 and 13 show the flow of ENG torque FB processing by WSC at cryogenic temperature. Hereinafter, based on FIG. 12 and FIG. 13, each step representing the ENG torque FB processing configuration by WSC at cryogenic temperature will be described.

ENG Torque FB at cryogenic temperature realizes TCS required torque while preventing engine stall due to rotation reduction by performing only support to prevent rotation reduction while watching the lower limit rotation speed at the time of TCS control intervention I can do it. That is, if TCS control intervenes during CL2 slip at an extremely low temperature, the process proceeds from step S121 to step S122 to step S124 in FIG. 12. In step S124, ENG torque FB is performed only on the torque-up side (0 Nm or more). Limit). If the TCS is not controlled during CL2 slip at an extremely low temperature, the process proceeds from step S121 to step S122 to step S123 in FIG. 12, and in step S123, ENG torque FB is performed. Then, during CL2 slip at an extremely low temperature, the process proceeds from step S125 to step S126 in FIG. 13, and in step S126, the ENG torque FB amount is
ENG torque FB amount = (actual ENG rotational speed−target rotational speed) × gain is calculated.

Next, the operation will be described.
The operation of the control device for the FF hybrid vehicle according to the first embodiment will be described separately in [Problem when TCS control intervenes during WSC mode] and [TCS-compatible control operation during WSC mode].

[Issues when TCS control intervenes in WSC mode]
FIG. 14A shows each characteristic when TCS control is not performed when TCS control intervenes at time t1 in the WSC mode. In this case, the target MG speed is
Target MG speed = primary speed + slip amount. Therefore, if TCS control intervenes at time t1, the relationship of target MG rotation speed> actual MG rotation speed (= ENG / MG rotation speed) is established, so the motor / generator tries to increase the rotation by generating torque. To do. On the other hand, in the state where CL2 friction μ where wheel spin occurs> road surface μ, the rotation speed on the output side (drive wheel side) of the second clutch CL2 increases and the second clutch CL2 is engaged for a while from the time t1. (Actual MG speed = wheel speed).
Therefore, originally, as indicated by the dotted line characteristic of the arrow A in FIG. 14 (a), the second clutch CL2 slips and the wheel speed is desired to converge with good response from the start of the TCS control. The convergence of the wheel spin (wheel speed) of the drive wheel is delayed from the start of the operation.

  In view of this, a comparative example in which an upper limit is set for the target MG rotation speed for the purpose of wheel spin convergence of the drive wheel is used. FIG. 14B shows each characteristic when the TCS control of the comparative example is performed when the TCS control intervenes at time t1 during the WSC mode. In the case of this comparative example, the increase in wheel speed is suppressed by the upper limit of the target MG rotation speed, so that the wheel spin of the drive wheel converges with good response and the vehicle behavior is stabilized early. However, as shown in the torque characteristics surrounded by arrow B in FIG. 14 (b), from time t1 to time t2, ENG + MG torque exceeds TCS torque down, and from time t2 to time t3, ENG + MG against TCS torque down. There is a torque difference between the two so that the torque is lower. Thus, when the TCS control intervenes during the WSC mode, there is a problem that the torque accuracy with respect to the TCS torque request is low during the motor rotation speed control.

[Control action for TCS in WSC mode]
As described above, when TCS control intervenes during the WSC mode, there is a request to increase the torque accuracy with respect to the TCS torque request during motor rotation speed control. Hereinafter, based on FIG. 7, FIG. 8, and FIG. 15, the TCS correspondence control action in the WSC mode reflecting this will be described.

As TCS compatible control in WSC mode,
(a) The target MG rotational speed is set to the lower limit rotational speed determined from the system requirements while performing the MG rotational speed control.
(b) The MG lower limit torque that can be used during MG rotation speed control is determined as being equivalent to the TCS required torque.
Was to be implemented.
With regard to (a) above, when the motor / generator 4 is under rotational speed control and TCS control, the process proceeds from step S81 to step S82 to step S84 in the flowchart of FIG. In step S74, the target MG rotation speed is set to the lower limit rotation speed determined from the system request.
With regard to (b) above, when the motor / generator 4 is under rotational speed control and TCS control, the process proceeds from step S71 to step S72 to step S74 in the flowchart of FIG. In step S74, the MG lower limit torque is set to the torque equivalent to the required torque in the TCS control, that is, the torque obtained by subtracting the estimated engine torque value from the TCS required torque down driving force.

FIG. 15 shows each characteristic in the case where the TCS control of the first embodiment is performed when the TCS control intervenes during the WSC mode.
First, at time t1 to time t4 during the TCS control intervention, the target MG rotation speed is set to the lower limit rotation speed determined from the system request, and the MG lower limit torque is set to be equivalent to the request torque in TCS control. Therefore, it is in the MG rotation speed control state, and the actual MG rotation speed ≧ the target MG rotation speed is satisfied, and the rotation speed fluctuation of the actual MG rotation speed exceeding the lower limit rotation speed is allowed. For this reason, the actual MG torque is in line with the MG lower limit torque. Specifically, in the range of actual MG rotation speed> target MG rotation speed (t1 to t2, t3 to t4), the actual MG torque hits the MG lower limit torque, but the actual MG rotation speed = target MG rotation speed area (t2 to t3) ), Actual MG torque slightly exceeds MG lower limit torque.

  Since the MG lower limit torque is set to be equivalent to the required torque in the TCS control, the TCS required torque can be realized by the actual MG torque generated along the MG lower limit torque. Furthermore, even if the actual MG rotational speed is about to fall below the system-required lower limit rotational speed, the actual MG rotational speed is supported by the lower limit rotational speed, so that engine stall can be avoided. That is, it is possible to achieve both the avoidance of engine stall due to excessive reduction of the actual MG rotation speed and the realization of the TCS required torque.

In the first embodiment, when TCS control intervenes during slip engagement control of the second clutch 5, the motor / generator 4 is set to MG rotation speed control, and the target MG rotation speed is set to the lower limit rotation speed determined by the system requirement. It was adopted.
That is, the lower limit rotational speed set as the target MG rotational speed is a rotational speed that maintains the actual MG rotational speed above this rotational speed. For this reason, if TCS control intervenes during the WSC mode based on the slip engagement control of the second clutch 5, the target MG rotation speed ≤ the actual MG rotation speed is satisfied, and the motor / generator 4 does not have to increase the rotation by generating torque, and the icing Excessive torque is prevented even on extremely low μ roads such as roads.
On the other hand, the lower limit rotational speed set as the target MG rotational speed is a rotational speed that suppresses a decrease in the actual MG rotational speed from this rotational speed. For this reason, even if the actual MG rotation speed decreases to a rotation speed lower than the system-required lower limit rotation speed, the lower limit rotation speed serves as a support, and engine stall is prevented.
As a result, when TCS control intervenes during slip engagement control of the second clutch 5, it is possible to achieve excessive torque prevention and engine stall prevention.

In the first embodiment, a configuration is adopted in which the lower limit rotational speed determined from the system requirements is adjusted and set to the rotational speed at which the required driving force can be obtained by TCS control.
For example, if the actual MG rotation speed is too low in the wheel speed rotation convergence region indicated by arrow C in FIG. 15, there is a problem that the driving force for climbing the uphill road is insufficient.
On the other hand, as shown by the arrow D in FIG. 15, the lower limit rotational speed is adjusted to a rotational speed at which the required driving force can be obtained by TCS control, thereby suppressing a decrease in the actual MG rotational speed that causes insufficient driving force. Therefore, it is possible to secure a driving force for climbing uphill.

In the first embodiment, the rotational speed at which the required driving force can be output is set to a higher rotational speed as the required driving power is larger, and is set to a higher rotational speed as the output from the high-power battery 21 that is the power source of the motor / generator 4 is restricted. The configuration to adopt was adopted.
That is, by setting a higher rotational speed as the required driving force is larger, an appropriate lower limit rotational speed corresponding to the traveling load can be set. Further, by setting the rotation speed so high that the output from the high-power battery 21 that is the power source of the motor / generator 4 is limited, it is possible to set an appropriate lower-limit rotation speed corresponding to the actual MG torque that can be output from the high-power battery 21.
Therefore, it is possible to set an appropriate lower limit rotational speed corresponding to the travel load and the actual MG torque that can be output.

Next, the effect will be described.
In the control apparatus for the FF hybrid vehicle according to the first embodiment, the effects listed below can be obtained.

(1) The drive system has an engine (horizontal engine 2), a motor (motor / generator 4), a friction engagement element (second clutch 5), and drive wheels (left and right front wheels 10L, 10R). ,
The rotational speed of the motor (motor / generator 4) is controlled to be the rotational speed of the motor that matches the target motor rotational speed that secures the slip amount of the frictional engagement element (second clutch 5). 5) In a hybrid vehicle control device comprising slip fastening control means (hybrid control module 81) for slip fastening with a capacity equivalent to the required driving force,
When it is detected that wheel spin has occurred on the drive wheels (left and right front wheels 10L and 10R), the traction reduces the drive torque transmitted from the drive wheels (left and right front wheels 10L and 10R) to the road surface, thereby reducing the amount of wheel spin. Provide traction control means (VDC / TCS control unit 85) to control,
When the traction control intervenes during slip engagement control of the friction engagement element (second clutch 5), the slip engagement control means (hybrid control module 81) sets the motor (motor / generator 4) to motor rotation speed control. On the other hand, a motor lower limit rotational speed setting unit (FIG. 8) is provided for setting the target motor rotational speed to a lower limit rotational speed determined from system requirements.
For this reason, when traction control (TCS control) intervenes during slip engagement control (in the WSC mode) of the friction engagement element (second clutch 5), it is possible to achieve excessive torque prevention and engine stall prevention.

(2) The motor lower limit rotational speed setting unit (FIG. 8) adjusts and sets the lower limit rotational speed determined from the system request to a rotational speed at which the required driving force can be generated by the traction control.
For this reason, in addition to the effect of (1), a decrease in the actual motor speed (actual MG speed) that causes insufficient driving force is suppressed, and driving force to drive through high load roads such as uphill roads is secured. can do.

(3) The motor lower limit rotational speed setting unit (FIG. 8) sets the rotational speed at which the required driving force can be output to a higher rotational speed as the required driving force increases, and the motor (motor / generator 4) power supply. The number of revolutions is set so high that the output from the battery (high-power battery 21) is limited.
For this reason, in addition to the effect of (1) or (2), it is possible to set an appropriate lower limit rotational speed corresponding to the running load and the actual motor torque that can be output (actual MG torque).

(4) When the traction control intervenes during the slip engagement control of the friction engagement element, the slip engagement control means (hybrid control module 81) controls the motor (motor / generator 4) while controlling the motor rotation speed. A motor lower limit torque setting unit (FIG. 7) that determines a motor lower limit torque that can be used during the rotation speed control as an equivalent to the required torque in the traction control.
For this reason, in addition to the effects (1) to (3), it is possible to achieve both avoidance of engine stall due to excessive reduction in the actual motor rotation speed (actual MG rotation speed) and realization of the TCS required torque.

  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, as the motor lower limit rotation speed setting unit, an example is shown in which the lower limit rotation speed determined from the system request is adjusted and set to the rotation speed at which the required driving force can be obtained by TCS control. However, the motor lower limit rotational speed setting unit may be an example in which the lower limit rotational speed is a fixed value determined from system requirements.

  In Example 1, the preferable example which has both a motor lower limit rotation speed setting part (FIG. 8) and a motor lower limit torque setting part (FIG. 7) as a slip fastening control means was shown. However, the slip fastening control means may be an example having only the motor lower limit rotational speed setting unit.

  In Example 1, the example which applies the control apparatus of this invention to FF hybrid vehicle was shown. However, the control device of the present invention can be applied not only to FF hybrid vehicles but also to FR hybrid vehicles and 4WD hybrid vehicles. In short, any hybrid vehicle having an engine, a motor, a frictional engagement element, and drive wheels in the drive system can be applied.

1 Starter motor 2 Horizontal engine (engine)
3 First clutch 4 Motor / generator (motor)
5 Second clutch (friction engagement element)
6 Belt type continuously variable transmission 10R, 10L Left and right front wheels (drive wheels)
11R, 11L Left and right rear wheels 21 High-power battery (battery)
22 12V battery 81 hybrid control module (slip fastening control means)
85 VDC / TCS control unit (traction control means)

Claims (3)

The drive system has an engine, a motor, a friction engagement element, and a drive wheel,
Slip fastening control means for controlling the rotational speed of the motor to match the target motor rotational speed that secures the slip amount of the frictional engagement element, and slip-engaging the frictional engagement element with a capacity corresponding to the required driving force In a hybrid vehicle control device comprising:
When it is detected that wheel spin has occurred in the drive wheel, a traction control means is provided for performing traction control for reducing the drive torque transmitted from the drive wheel to the road surface and reducing the amount of wheel spin,
When the traction control intervenes during the slip engagement control of the friction engagement element, the slip engagement control means sets the target motor rotation speed to a lower limit rotation speed determined by system requirements while setting the motor to motor rotation speed control. have a motor limit rotation speed setting unit,
The motor lower limit rotational speed setting unit adjusts and sets the lower limit rotational speed determined from a system request to a rotational speed at which a required driving force can be generated by the traction control . In the hybrid vehicle control device according to claim 1 ,
The motor lower limit rotational speed setting unit sets the rotational speed at which the required driving force can be output to a higher rotational speed as the required driving power is larger, and can output as the output from the battery that is a power source of the motor is restricted. A control apparatus for a hybrid vehicle, characterized in that it is set to a rotational speed corresponding to an actual motor torque . In the hybrid vehicle control device according to claim 1 or 2 ,
When the traction control intervenes during the slip engagement control of the friction engagement element, the slip engagement control means sets the motor lower limit torque that can be used during the motor rotation speed control while setting the motor to the motor rotation speed control. A control apparatus for a hybrid vehicle, comprising: a motor lower limit torque setting unit that is determined as equivalent to a required torque in control.