JP5350772B2 - Vehicle drive control device and start control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce or release driving force restriction at the start by restriction of clutch transmission torque while protecting clutches. <P>SOLUTION: When the drive controller for a vehicle detects a vehicle start request, the drive controller controls drive torque of a drive source to target start drive torque, and controls a second clutch CL2 constituting a part of a transmission to be slip-engaged. Thereby, the drive torque of the drive source is transmitted to drive wheels through the transmission. At that time, the drive controller performs shift transmission and changes the clutch to be slip-engaged when deciding that a temperature of the second clutch CL2 is a predetermined protection temperature or above. The drive controller suppresses fluctuation of output torque of the transmission. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a vehicle drive control device and a start control method for starting a vehicle with a drive torque of a motor or an engine.

As a conventional start control device, there is a device described in Patent Document 1, for example. This device is configured to connect a motor, a second clutch, and a drive wheel in this order. And if the start from the standby state by a driver | operator's accelerator depression operation is detected, a driving torque will be transmitted to a driving wheel by carrying out sliding engagement of the 2nd clutch. At this time, the clutch facing temperature rise at the time of complete engagement is obtained from the clutch slip amount and the current oil temperature. Then, the target clutch engagement torque of the second clutch is limited to the highest engagement torque that falls within the clutch protection temperature due to this temperature rise. As a result, the second clutch is protected.
JP 2006-315488 A

In the conventional example, the target clutch engagement torque is limited to the highest engagement torque that falls within the clutch protection temperature. This limits the clutch transmission torque. This limitation of the clutch transmission torque is a limitation on the driving at the time of starting.
The present invention has been made in consideration of the above-described points, and an object of the present invention is to reduce or cancel the driving force limitation at the start by limiting the clutch transmission torque while protecting the clutch.

In order to solve the above problems, the present invention detects the vehicle start request, the driving torque of the driving source to control the goals driving torque, the sliding engagement of the first clutch forming part of the transmission By controlling, the drive torque of the drive source is transmitted to the drive wheels via the transmission. At this time, if the temperature of the first clutch is determined to be equal to or higher than the predetermined protection temperature , an up-shift command that is a command to shift up by changing the gear ratio is output regardless of the shift schedule, and among the clutches in the transmission, A clutch after an upshift different from the first clutch is selected, and the upshift is completed by slidingly engaging the selected clutch . Further, in synchronization with the output of the upshift command, the target drive torque is increased in accordance with the change in the output torque of the transmission due to the shift.

According to the present invention, it is possible to protect the clutch from heat generation of the clutch by selecting and changing the clutch to be engaged by sliding according to the clutch temperature.
Further, by selecting and changing the clutch that is slip-engaged according to the state of heat generation of the clutch, it is possible to adjust the time during which the slip is engaged according to the state of heat generation of the clutch. For this reason, it becomes possible to avoid or reduce the limit of the target clutch engagement torque of the clutch that is slidingly engaged.
From the above, it becomes possible to reduce or cancel the driving force limitation at the start by limiting the clutch transmission torque while protecting the clutch.

Next, embodiments of the present invention will be described with reference to the drawings.
In the present embodiment, a hybrid vehicle will be described as an example of the vehicle, but the present invention can also be applied to a vehicle that is driven only by an engine or a motor.
FIG. 1 is a schematic configuration diagram of a rear-wheel drive hybrid vehicle including the braking / driving device of the embodiment.

(Constitution)
First, the configuration of the drive system will be described.
A motor MG and an automatic transmission AT (= transmission T / M) are interposed in the middle of the torque transmission path from the engine E to the left and right rear wheels (drive wheels). The second clutch CL2 constitutes a part of the automatic transmission AT (= transmission T / M). Further, the first clutch CL1 is interposed between the engine E and the motor MG. The automatic transmission AT is connected to drive wheels via a propeller shaft PS, a differential DF, and drive shafts DSL and DSR. Reference symbols FL and FR indicate left and right front wheels as driven wheels.

The engine E is a gasoline engine or a diesel engine. The engine can control the valve opening of the throttle valve and the like based on a control command from an engine controller 1 described later. A flywheel FW is provided on the output shaft of the engine E.
The motor MG is a synchronous motor in which a permanent magnet is embedded in a rotor and a stator coil is wound around a stator, for example. The motor MG can be controlled by applying a three-phase AC generated by the inverter 3 based on a control command from the motor controller 2 described later. The motor MG can also operate as an electric motor that rotates by receiving power supplied from the battery 4 (hereinafter, this state is referred to as “power running”). Further, when the rotor is rotated by an external force, the motor MG can function as a generator that generates an electromotive force at both ends of the stator coil to charge the battery 4 (hereinafter, this operation state is referred to as “ Called "regeneration"). Note that the rotor of the motor MG is connected to the input shaft of the automatic transmission AT via a damper (not shown).

The first clutch CL1 is a hydraulic single-plate clutch interposed between the engine E and the motor MG. The first clutch CL1 is brought into an engaged state or a released state by a control hydraulic pressure generated by the first clutch hydraulic unit 6 based on a control command from a first clutch controller 5 described later. The fastening / opening includes sliding fastening and sliding opening.
The second clutch CL2 is a hydraulic multi-plate clutch. The second clutch CL2 is brought into an engaged state or a released state by a control hydraulic pressure generated by the second clutch hydraulic unit 8 based on a control command from an AT controller 7 described later. The fastening / opening includes sliding fastening and sliding opening.

The automatic transmission AT is a transmission that automatically switches, for example, a stepped gear ratio such as 5th forward reverse 1st speed or 6th forward reverse 1st speed according to vehicle speed, accelerator opening, or the like. FIG. 2 shows a configuration example of the transmission AT. FIG. 2 shows the case of the first speed. FIG. 3 illustrates the case of the second speed control. The clutch indicated as CL2 in FIG. 3 shows an example of a clutch that performs slip engagement control when shifting to the second speed. The clutch that performs the slip engagement control when shifting to the second speed may be a clutch different from the clutch shown in FIG. Two or more clutch candidates for sliding engagement may be selected, and the lower clutch temperature may be selected.
Here, the second clutch CL2 is not newly added as a dedicated clutch, and some frictional engagement elements among a plurality of frictional engagement elements that are engaged at each gear stage of the automatic transmission AT are used. Configure.

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

  The engine controller 1 inputs engine speed information from the engine speed sensor 12. Then, the engine controller 1 outputs a command for controlling the engine operating point (Ne, Te), for example, to a throttle valve actuator (not shown) in accordance with a target engine torque command or the like from the integrated controller 10. Information on the engine speed Ne is supplied to the integrated controller 10 via the CAN communication line 11.

  The motor controller 2 inputs information from the resolver 13 that detects the rotor rotational position of the motor MG. Then, the motor controller 2 outputs a command for controlling the motor operating point (Nm, Tm) of the motor MG to the inverter 3 in accordance with a target motor torque command or the like from the integrated controller 10. The motor controller 2 monitors the battery SOC indicating the state of charge of the battery 4, and the battery SOC information is used as control information for the motor MG and is supplied to the integrated controller 10 via the CAN communication line 11. .

The first clutch controller 5 inputs sensor information from the first clutch oil pressure sensor 14 and the first clutch stroke sensor 15. Then, the first clutch controller 5 outputs a command for controlling the engagement / release of the first clutch CL <b> 1 to the first clutch hydraulic unit 6 in response to the first clutch control command from the integrated controller 10. Information on the first clutch stroke C1S is supplied to the integrated controller 10 via the CAN communication line 11.
The AT controller 7 inputs sensor information from the accelerator opening sensor 16, the vehicle speed sensor 17, and the second clutch hydraulic pressure sensor 18. Then, the AT controller 7 calculates a target shift speed with reference to the shift schedule based on the accelerator opening and the vehicle speed, and performs shift control based on the calculated target shift speed.

  Further, the AT controller 7 gives priority to the second clutch control in the shift control in response to the second clutch control command from the integrated controller 10, and gives a command for controlling the engagement / release of the second clutch CL2 in the AT hydraulic control valve. To the second clutch hydraulic unit 8. Also, at this time, the AT controller 7 gives priority to the shift control by the calculated target shift speed, and issues a command for shifting and engaging some clutches according to a command from a slip engagement processing unit 10H described later. , Output to the clutch hydraulic unit in the AT hydraulic control valve and the above-mentioned sliding engagement. Information on the accelerator opening AP and the vehicle speed VSP is supplied to the integrated controller 10 via the CAN communication line 11.

  The brake controller 9 inputs sensor information from a wheel speed sensor 19 and a brake stroke sensor 20 that detect the wheel speeds of the four wheels. The brake controller 9 calculates a target deceleration P0 based on the stroke amount of the brake pedal and the vehicle speed VSP in a predetermined control cycle. Then, a braking force command value is output to the brake unit of each wheel so that deceleration corresponding to the target deceleration P0 occurs in the vehicle. The brake controller 9 performs regenerative cooperative brake control when, for example, when the brake is depressed, if the regenerative braking force is insufficient with respect to the required braking force obtained from the brake stroke BS. That is, regenerative cooperative brake control is performed based on a regenerative cooperative control command from the integrated controller 10 so that the shortage is compensated by mechanical braking force (hydraulic braking force or motor braking force).

  The integrated controller 10 manages the energy consumption of the entire vehicle and bears a function for running the vehicle with the highest efficiency. The integrated controller 10 detects a motor rotation speed sensor 21 that detects a motor rotation speed Nm, a second clutch output rotation speed sensor 22 that detects a second clutch output rotation speed N2out, and a second clutch engagement torque TCL2. Information from the two-clutch engagement torque sensor 23 is input. Further, the integrated controller 10 inputs information acquired via the CAN communication line 11. Then, the integrated controller 10 executes operation control of the engine E according to a control command to the engine controller 1. The integrated controller 10 performs operation control of the motor MG in response to a control command to the motor controller 2. The integrated controller 10 executes engagement / disengagement control of the first clutch CL <b> 1 according to a control command to the first clutch controller 5. The integrated controller 10 executes the engagement / release control of the second clutch CL <b> 2 according to a control command to the AT controller 7.

Next, the basic operation mode will be described.
If the battery SOC is low while the vehicle is stopped, the engine E is started to generate electric power, and the battery 4 is charged. When the battery SOC is in the normal range, the first clutch CL1 is engaged and the second clutch CL2 is released, and the engine E is stopped.
When the engine starts, the motor MG is rotated according to the accelerator opening AP and the battery SOC state to switch to power running / power generation.

When the motor starts, when the output rotation of the automatic transmission AT becomes negative due to rollback, slip control of the second clutch CL2 is performed, and the rotation of the motor MG is maintained at the positive rotation. Next, the driving force is increased until the vehicle moves forward, and the second clutch CL2 is shifted from slip control to engagement.
Motor running secures motor torque and battery output necessary for starting the engine, and shifts to engine running if insufficient.
To improve fuel economy, motor driving and power generation are charged as a set. In other words, the travelable range is limited to a low load due to restrictions on motor torque and battery output.

The power generation additional charging is performed by adding the power generation torque to the torque necessary for traveling, aiming at the minimum point of engine fuel consumption. However, power generation is not performed when the battery SOC rises.
To improve the response when the accelerator is depressed, the motor MG assists the engine torque delay.
At the time of brake-on deceleration, a deceleration force corresponding to the driver's brake operation is obtained by regenerative cooperative brake control.
At the time of shifting during engine traveling or motor traveling, the motor MG is regenerated / powered to adjust the rotational speed associated with the shifting during acceleration / deceleration to perform smooth shifting without a torque converter.

  As shown in FIG. 4, the integrated controller 10 includes a drive control unit main body 10A, a target engine torque calculation unit 10B, a target clutch torque calculation unit 10C, a target motor torque calculation unit 10D, and an engine running as a processing unit related to start control. A mode target engine torque calculation unit 10E, an engine travel mode target clutch torque calculation unit 10F, an engine travel mode target motor torque calculation unit 10G, and a slip engagement processing unit 10H are provided.

The processing of the drive control unit main body 10A will be described with reference to FIG.
The drive control unit body 10A is an overall processing unit for hybrid drive control (engine control, motor control, first clutch control, second clutch control).
The drive control unit body 10A executes at a predetermined sampling period. When executed, the drive control unit main body 10A first calculates a target driving force in step S1 based on the battery SOC, the battery input available power, and the accelerator opening.

Next, in step S2, the target shift speed is calculated with reference to the shift schedule based on the vehicle speed and the accelerator opening.
In step S3, the target mode is calculated with reference to the mode map based on the target driving force and vehicle speed calculated in step S1.
Here, as the target mode, there are an “engine running mode” and an “electric motor mode (hereinafter,“ EV mode ”). The “engine running mode” is a mode in which the first clutch CL1 is engaged and the engine E is a main power source. The “EV mode” is a mode in which the first clutch CL1 is released and the motor MG is used as a power source. For example, the “engine running mode” is selected in an area where the target driving force is large.

In step S4, the target engine torque calculation unit 10B calculates the target engine torque based on the target driving force.
In step S5, it is calculated whether the mode transition from the “engine travel mode” to the “EV mode” or the mode transition from the “EV mode” to the “engine travel mode”.
In step S6, the target clutch torque calculation unit 10C calculates the target clutch engagement capacity of the first clutch CL1 and the target clutch engagement capacity of the second clutch CL2.

In step S7, the target driving force transient correction is performed in the transition period in which the target driving force changes.
In step S8, the target motor torque calculation unit 10D calculates the target motor torque of the motor MG.
In step S9, final command values for the engine controller 1, motor controller 2, first clutch controller 5, and AT controller 7 are calculated and returned.

Next, the processing of the target engine torque calculation unit 10B will be described with reference to FIG. The target engine torque calculation unit 10B is a target engine torque calculation process executed in step S4.
First, in step S41, it is determined whether or not the target mode is the engine travel mode. When the target mode is the engine running mode, the process proceeds to step S42. On the other hand, when the target mode is not the engine travel mode, the process proceeds to step S45.

In step S42, it is determined whether or not the current mode is the engine running mode. If the current mode is the engine running mode, the process proceeds to step S43. On the other hand, if the current mode is not the engine running mode, the process proceeds to step S44.
In step S43, the engine driving mode target engine torque calculation unit 10E calculates the target engine torque during the engine driving mode, and returns.

In step S44, the target engine torque at the time of engine start is calculated, and the process returns.
In step S45, it is determined whether or not the current mode is the engine running mode. When the current mode is the engine running mode, the process proceeds to step S46. On the other hand, if the current mode is not the engine running mode, the process proceeds to step S47.
In step S46, the target engine torque at the time of transition to the EV mode is calculated and returned.
In step S47, the calculation of the target engine torque in the EV traveling mode is performed and the process returns.

Next, the processing of the target clutch torque calculation unit 10C will be described with reference to FIG. The target clutch torque calculator 10C is a target clutch torque calculation process executed in step S6.
In step S61, it is determined whether the target mode is the engine travel mode. When the target mode is the engine running mode, the process proceeds to step S62. On the other hand, when the target mode is not the engine running mode, the process proceeds to step S65.
In step S62, it is determined whether or not the current mode is an engine running mode. When the current mode is the engine running mode, the process proceeds to step S63. On the other hand, when the current mode is not the engine running mode, the process proceeds to step S64.

In step S63, the target clutch torque calculation unit for engine driving mode 10F calculates the target clutch torque during the engine driving mode and returns.
In step S64, the target clutch torque at the time of engine start is calculated, and the process returns.
In step S65, it is determined whether or not the current mode is the engine running mode. When the current mode is the engine running mode, the process proceeds to step S66. On the other hand, if the current mode is not the engine running mode, the process proceeds to step S67.
In step S66, the target clutch torque at the time of transition to the EV mode is calculated and returned.
In step S67, the target clutch torque in the EV traveling mode is calculated and returned.

Next, the target motor torque processing unit will be described with reference to FIG. The target motor torque processing unit is a target motor torque calculation process executed in step S8.
Step S81 determines whether or not the target mode is the engine travel mode. When the target mode is the engine running mode, the process proceeds to step S82. On the other hand, when the target mode is not the engine travel mode, the process proceeds to step S85.
In step S82, it is determined whether or not the current mode is an engine running mode. When the current mode is the engine running mode, the process proceeds to step S83. On the other hand, if the current mode is not the engine running mode, the process proceeds to step S84.

In step S83, the engine driving mode target motor torque calculation unit 10G calculates the target motor torque in the engine driving mode, and returns.
In step S84, the target motor torque at the time of starting the engine is calculated and returned.
In step S85, it is determined whether or not the current mode is the engine running mode. When the current mode is the engine running mode, the process proceeds to step S86. If the current mode is not the engine running mode, the process proceeds to step S87.
In step S86, the target motor torque at the time of transition to the EV mode is calculated and returned.
In step S87, the target motor torque in the EV travel mode is calculated and returned.

Next, the processing of the engine running mode target engine torque calculation unit 10E will be described with reference to FIG. The engine travel mode target engine torque calculation unit 10E is a target engine torque calculation process in the engine travel mode executed in step S43.
In step S43-1, it is determined whether or not the conditions of vehicle speed ≦ determination threshold, required driving force ≦ 0, and accelerator opening> 0 are satisfied. If the condition is satisfied, the process proceeds to step S43-3. If the condition is not satisfied, the process proceeds to step S43-2.

  That is, when the vehicle is stopped without the required driving force (vehicle speed ≦ determination threshold, required driving force ≦ 0) by determining whether the three conditions of the vehicle speed condition, the required driving force condition, and the accelerator opening condition are satisfied, A situation where the vehicle is on standby while generating an engine torque due to an accelerator opening degree> 0) is observed. The “required driving force” can be obtained from the sum of the driving force that can be generated by the target engine speed determined by the accelerator opening and the braking force that is generated by depressing the brake. Further, the selection determination of the N range position may be performed by the inhibitor switch 24 instead of the determination that the vehicle speed ≦ the determination threshold and the required driving force ≦ 0. In this case, when the N range position is selected and the accelerator opening degree> 0, the process proceeds to step S43-3, and when the N → D selection or the N → R selection with the accelerator opening degree> 0 remains, the step S43- Move to 2.

In step S43-2, the target engine torque in the normal engine travel mode is calculated. For example, the target engine torque is calculated in consideration of the motor torque with respect to the driving force request according to the accelerator opening, and then returned.
In step S43-3, the set rotational speed corresponding to the accelerator opening is set as the target engine rotational speed, and the process proceeds to step S43-4.

In step S43-4, battery-inputtable power (battery SOC maximum value-battery SOC detection value) is set as regenerative battery power, and the process proceeds to step S43-5.
In step S43-5, the value obtained by the equation (regenerative battery power ÷ target engine speed × motor efficiency) is set as the battery inputable torque, and the process proceeds to step S43-6.

In step S43-6, the target engine speed engine torque is set using the target engine speed-accelerator opening degree table, and the process proceeds to step S43-7.
In step S43-7, it is determined whether or not the battery input possible torque obtained in step S43-5 is less than the target rotational speed engine torque obtained in step S43-6. If the condition is satisfied, the process proceeds to step S43-8. If the condition is not satisfied, the process proceeds to step S43-9.
In step S43-8, the battery input allowable torque is substituted for the target engine torque, and the process returns.
In step S43-9, the target engine speed is substituted for the target engine torque, and the process returns.

Next, the process of the engine travel mode target clutch torque calculator 10F will be described with reference to FIG. The engine travel mode target clutch torque calculation unit 10F is a target clutch torque calculation process in the engine travel mode executed in step S63.
In step S63-1, it is determined whether or not the conditions of vehicle speed ≦ determination threshold, required driving force ≦ 0, and accelerator opening> 0 are satisfied. If the condition is satisfied, the process proceeds to step S63-2. If the condition is not satisfied, the process proceeds to step S63-3. Similar to step S43-1, the selection of the N range position may be performed by the inhibitor switch 24 instead of the determination that the vehicle speed ≦ the determination threshold and the required driving force ≦ 0.

In step S63-2, 0 [Nm] (disengagement of the second clutch CL2) is substituted for the target second clutch engagement torque, and the process returns.
In step S63-3, it is determined whether or not a clutch slip process is being performed in the transmission AT. Here, the determination is made based on whether or not the vehicle speed is equal to or lower than the clutch L / U vehicle speed. When the vehicle speed is equal to or lower than the clutch L / U vehicle speed, it is determined that the clutch slip process is being performed, and the process proceeds to step S63-4. If the clutch slip process is not being performed, the process proceeds to step S63-9.

In step S63-4, the set rotational speed corresponding to the accelerator opening is set as the target engine rotational speed, and the process proceeds to step S63-5.
Here, the target engine speed is a speed corresponding to the accelerator opening, which is set within a range in which the motor torque can be regenerated depending on the battery input state. Further, the target engine speed is a speed that does not fall below the idle speed due to a decrease in the engine speed due to the engagement of the second clutch CL2.

In step S63-5, the second clutch engagement torque is calculated with reference to the map based on the target engine speed. And the calculated 2nd clutch fastening torque is set as a target 2nd clutch fastening torque, and it transfers to step S63-6.
In step S63-6, the slip fastening processing unit 10H calculates the slip fastening processing of the transmission AT and returns.
In step S63-9, the calculation of the target second clutch engagement torque during normal engine running is performed, and the process proceeds to the end.

Next, the process of the slip fastening process part 10H is demonstrated with reference to FIG. The slip engagement processing unit 10H calculates the slip engagement processing of the transmission AT in Step S63-5.
First, in step S100, it is determined whether or not the second clutch CL2 is being slipped at the first speed. When the slip process of the second clutch CL2 is being performed, the process proceeds to step S120. When the slip process of the second clutch CL2 is not in progress, the process proceeds to step S210.

In step S120, the heat generation amount (Q1) of the second clutch CL2 is estimated by calculation. Then, the process proceeds to step S130.
The calorific value (Q1) of the second clutch CL2 is obtained by the following equation.
Q1 = Tc × ω × Δt
However,
Tc: Transmission torque of second clutch CL2 (clutch end)
ω: slip rotation of second clutch CL2 (clutch end)
Δt: 2π / 60 (seconds)
It is.

Further, the clutch transmission torque can be obtained by the following equation.
Clutch transmission torque
= {(Input shaft torque to transmission AT)-(Friction torque of transmission AT)}
X Torque sharing ratio Here, the torque sharing ratio is the ratio of the torque applied to the target clutch itself to the torque of the input shaft.

Further, the slip rotation of the clutch can be obtained by the following equation.
Clutch slip rotation
= {(Input shaft rotation of transmission AT)-(output shaft rotation of transmission AT) × (gear ratio)}
X Rotational speed ratio Here, the rotational speed ratio is the reciprocal of the torque sharing ratio.

In step S130, it is determined whether or not the heat generation amount (Q1) of the second clutch CL2 is larger than a predetermined heat generation amount Q1L. When the heat generation amount (Q1) of the second clutch CL2 is larger than the predetermined heat generation amount Q1L, the process proceeds to step S140. When the heat generation amount (Q1) of the second clutch CL2 is equal to or less than the predetermined heat generation amount Q1L, the second clutch CL2 returns. The predetermined temperature Q1L is set to a temperature slightly lower than the temperature at which clutch burn-in may occur, for example.
In step S140, an upshift command is output. Specifically, a shift command to the second speed is output.

In step S150, the clutch to be slipped after the shift is selected. A clutch that is fastened at the second speed and is different from the second clutch CL2 is selected as a clutch that is fastened by sliding (see FIG. 3).
In step S160, an additional torque ΔTin of the gear ratio difference due to the shift is calculated with respect to the input torque of the transmission AT so that the output torque of the transmission AT becomes constant during the shift.
ΔTin = ((Tin × Gz) − (Tin × Gn)) / Gn
Here, ΔTin: Additional torque during upshifting Tin: Input torque torque of transmission AT Gz gear ratio before shifting Gn: gear ratio after shifting.

In step S170, a gear shift command to the second speed is output to the AT controller 7 in a state where the slip target clutch is in the sliding engagement.
In step S180, the clutch temperature Q2 of the clutch to be slipped is calculated by the following equation.
Q2 = Tc × ω × Δt

  In step S190, it is determined whether or not the clutch temperature Q2 of the current slip target clutch is higher than a predetermined temperature Q2L. When the clutch temperature Q2 of the current slip target clutch is higher than the predetermined temperature Q2L, the process proceeds to step S200. When the clutch temperature Q2 of the current slip target clutch is equal to or lower than the predetermined temperature Q2L, the clutch is restored. The predetermined temperature Q2L is set to a temperature slightly lower than a temperature at which clutch burn-in may occur, for example. The predetermined temperature Q2L does not have to be the same temperature as the predetermined temperature Q1L. Also, the temperature at which clutch burnout may occur varies depending on the clutch configuration.

In step S190, a command for switching the slip target clutch to another engagement clutch in the same gear stage is output to the AT controller 7, and the process returns.
On the other hand, when it is determined that the slip processing is not performed in the second clutch CL2, and the process proceeds to step S210, the heat release amount Q1C of the second clutch CL2 is calculated, and the process proceeds to step S220. The heat release amount Q1C of the second clutch CL2 may be estimated by the time after the slip clutch in the second clutch CL2 is stopped.

In step S220, it is determined whether or not the heat release amount Q1C of the second clutch CL2 is smaller than a predetermined temperature Q1L. When the heat dissipation amount Q1C of the second clutch CL2 is smaller than the predetermined temperature Q1L, the process proceeds to step S240. If the heat dissipation amount Q1C of the second clutch CL2 is equal to or higher than the predetermined temperature Q1L, the process proceeds to step S230.
In step S230, the clutch engagement torque of the slip target clutch at the second speed is calculated and set with reference to the map based on the target engine speed. Then, the process proceeds to step S180.
In step S240, a shift command for lowering the shift stage is output. Specifically, a shift command from the second speed to the first speed is output.
In step S240, the additional torque ΔTin is set to zero and the process returns.

Next, the processing of the engine running mode target motor torque calculation unit 10G will be described with reference to FIG.
This is a calculation process of the target motor torque during the engine running mode executed in step S83.
In step S83-1, it is determined whether or not the conditions of vehicle speed ≦ determination threshold, required driving force ≦ 0, and accelerator opening> 0 are satisfied. If the condition is satisfied, the process proceeds to step S83-2. If the condition is not satisfied, the process proceeds to step S83-5. Similar to step S43-1, the selection of the N range position may be performed by the inhibitor switch 24 instead of the determination that the vehicle speed ≦ the determination threshold and the required driving force ≦ 0.

In step S83-2, it is determined whether the battery input possible torque is equal to or less than the target engine torque. If the condition is satisfied, the process proceeds to step S83-3. If the condition is not satisfied, the process proceeds to step S83-4.
In step S83-3, the torque for maintaining the target engine speed by PI feedback control within the range of the battery inputtable torque is set as the target motor torque (regenerative torque) and returned.

In step S83-4, the torque for maintaining the target engine speed by PI feedback control within the range of the target engine torque is set as the target motor torque (regenerative torque) and returned.
In step S83-5, it is determined whether clutch slip control is being performed in the transmission AT. When the clutch slip control is being performed, the process proceeds to step S83-6. If the clutch slip control is not being performed, the process proceeds to step S83-7.

In step S83-6, a positive torque obtained by the equation {target rotational speed engine torque− (target second clutch engagement torque + slip torque)} is set as the target motor torque, and the process proceeds to step S83-7.
That is, as the target motor torque when the second clutch CL2 is in the slip engagement state, the input torque to the second clutch CL2 that can be expressed by the difference from the target rotational speed engine torque is (target second clutch engagement torque + slip amount). Torque).

In step S83-7, the target motor torque is increased and corrected by an additional torque ΔTin. This suppresses fluctuations in the output torque of the transmission AT due to gear shifting. Thereafter, the target motor torque is set as a negative target motor torque obtained by reversing the sign of the target motor torque.
In step S83-8, the torque obtained by the equation (the amount of driving force−the amount of transmission of the first clutch CL1) is set as the target motor torque, and the process returns.
That is, the target motor torque is set so that the sum of the engine torque and the motor torque transmitted via the first clutch CL1 matches the driving force.

(Action / Operation)
[When the accelerator is depressed]
The N-range standby control is performed while generating engine torque by the driver's accelerator depressing operation. At this time, the engine torque control is processed in the order of step S43-1, step S43-3, step S43-4, step S43-5, and step S43-6. At this time, in step S43-3, the set rotational speed corresponding to the accelerator opening is set as the target engine rotational speed. In step S43-4, regenerative battery power is set. In step S43-5, the battery input possible torque is set based on the target engine speed and the regenerative battery power. In step S43-6, a target engine speed engine torque is set based on the target engine speed and the accelerator opening. If battery input rotational speed torque <target rotational speed engine torque, the process proceeds to step S43-8, and the battery input rotational speed torque is set as the target engine torque. On the other hand, if battery input rotational speed torque ≧ target rotational speed engine torque, the process proceeds to step S43-9, and the target rotational speed engine torque is set as the target engine torque.

At this time, when the accelerator is depressed and the N-range is standby, the clutch calculation processing unit executes the process from step S63-1 to step S63-2. At this time, in step S63-2, the target second clutch engagement torque is set to 0 [Nm]. That is, the 2nd clutch CL2 is made into an open state.
Of the controls when the accelerator is depressed and the N range is standby, in the motor torque control, when battery input rotational speed torque ≦ target engine torque, step S83-1 → step S83-2 → step S83-3 in the process of FIG. 3 is executed. At this time, in step S83-3, the torque for maintaining the target engine speed by PI feedback control within the range of the battery input possible torque is set as the target motor torque. On the other hand, when battery input rotational speed torque> target engine torque, in the process of FIG. 8, the process is executed from step S83-1 to step S83-2 to step S83-4. At this time, in step S83-4, the torque for maintaining the target engine speed by PI feedback control within the range of the target engine torque is set as the target motor torque.

  As described above, the target engine torque is set to the target engine speed for obtaining the target engine speed corresponding to the accelerator opening when the accelerator is depressed in the N range standby mode. Further, the target second clutch engagement torque is set to zero. Also, control is performed to set the target motor torque to a torque that maintains the target engine speed. For this reason, the engine / motor torque when the shift position is N is a negative motor torque with respect to the positive engine torque. That is, drive energy from the engine E can be recovered as battery power by the regenerative operation of the motor MG.

When the shift position is N, the engine speed is kept constant by motor torque control that maintains the target engine speed according to the accelerator opening. Further, the differential rotation of the second clutch CL2 appears as a difference between the rotational speed decelerated by the gear train upstream of the second clutch CL2 in the automatic transmission AT and the output rotational speed (= 0).
Here, the clutch torque capacity when the shift position is N is that the first clutch CL1 is in a completely engaged state and the second clutch CL2 is in an released state. The driving force when the shift position is N is maintained at zero.

Therefore, when the shift position before starting is N, the input torque to the second clutch CL2, which is the difference between the engine torque and the motor torque, can be waited for power-on starting while maintaining almost zero. In addition, the motor torque control that maintains the target engine speed according to the accelerator opening degree keeps the engine / motor speed constant, so that the differential rotation of the second clutch CL2 also keeps the constant speed and power-on start. Can wait.
Further, since the battery input possible torque based on the electric power that can be inputted to the battery 4 connected to the motor MG is set as a limit value and the target engine torque and the target motor torque are set, the battery 4 is charged as much as possible. While performing, overcharge can be reliably prevented.

[Control at start of start]
Next, the start control by N → D selection will be described.
The engine torque control is executed from step S43-1 to step S43-2. At this time, in step S43-2, the target engine torque is set in consideration of the motor torque in response to the driving force request corresponding to the accelerator opening.
In the slip clutch control, the process is executed in the order of step S63-1, step S63-3, step S63-4, and step S63-5. At this time, in step S63-4, the set rotational speed corresponding to the accelerator opening is set as the target engine rotational speed. In step S63-5, the clutch torque set on the map according to the target engine speed is set as the target second clutch engagement torque.

  In this slip clutch control, when the clutch to be slipped remains the second clutch (see FIG. 2), the clutch temperature of the second clutch CL2 is estimated in step S120. When the clutch temperature of the second clutch CL2 is equal to or higher than the predetermined temperature, the upshift is performed to the second speed regardless of the shift schedule in the processes of step S130 and step S140 (see FIG. 3). Further, one of the clutches to be engaged at the second speed is controlled to be slipped. At this time, the second clutch CL2 is in a completely engaged state or in a completely released state, so that it dissipates heat and cools by lubricating the lubricating oil. As a result, clutch wear due to an increase in the amount of heat generated by the second clutch CL2 can be suppressed.

  In addition, when the clutch temperature of the second clutch CL2 of the clutch that is in the slip engagement at the second speed becomes equal to or higher than the predetermined temperature by the processing in steps S180 to S200, the clutch that is engaged in the slip engagement in the current gear position (second speed). Change (replace). As a result, it is possible to suppress the wear of the clutch due to the increase in the amount of heat generated with respect to the clutch that is currently engaged in sliding engagement.

Further, even if the upshift is performed, if it is determined that the temperature of the second clutch CL2 has been cooled by heat dissipation, the speed is shifted down to the first speed to return to the initial slip clutch process.
At this time, the motor torque control executes processing from step S83-1 to step S83-5 to step S83-6 to step S83-7. At this time, in step S83-6, the target motor torque is set so that the input torque to the second clutch CL2 expressed by the difference from the target rotational speed engine torque becomes (target second clutch engagement torque + slip torque). Set. Furthermore, when the gear is shifted up to the second speed regardless of the shift schedule, the target motor torque is corrected to be increased by an amount corresponding to the additional torque ΔTin. This suppresses fluctuations in the output torque of the transmission AT due to shifting.

In FIG. 10, the example of a time chart about the clutch protection at the time of start processing is shown.
As described above, from the detection of the start of the start by the N → D selection to the end of the start control, the target engine torque is changed to a torque that satisfies the driving force request while considering the motor torque while appropriately changing the gear position. Set. Further, the target second clutch engagement torque is a second clutch engagement torque that maintains the target engine speed according to the accelerator opening. Further, the target motor torque is controlled so that the input torque to the second clutch CL2 becomes a torque obtained by adding the amount of torque transmitted by the target second clutch engagement torque and the slip amount torque of the second clutch CL2. At this time, the target motor torque is corrected according to the shift of the transmission AT.

Here, the engine and the motor constitute a drive source. The second clutch CL2 constitutes the first clutch.
The engine travel mode target engine torque calculation unit 10E, the engine travel mode target clutch torque calculation unit 10F, and the engine travel mode target motor torque calculation unit 10G constitute start control means.
Steps S120 and S180 constitute clutch temperature estimating means. Steps S130 to S170 and S200 constitute clutch changing means. Step S83-7 constitutes a target drive torque correction unit.

(Effect of this embodiment)
(1) Upon detecting a vehicle start request, the start control means controls the drive torque of the drive source to the target drive torque for start, and slides and engages the first clutch that constitutes a part of the transmission AT. By controlling to, the drive torque of the drive source is transmitted to the drive wheels. Clutch temperature estimating means estimates the temperature of the first clutch. When the clutch change means determines that the clutch temperature estimated by the clutch temperature estimation means is equal to or higher than a predetermined protection temperature, the clutch change means changes the clutch that is slip-engaged.

By changing the clutch forcibly slidingly engaged, it is possible to prevent wear of the clutch due to an increase in the amount of heat generated and extend the life of the clutch to be slipped engaged.
In addition, since the slip engagement time of the clutch that is slip-engaged can be set freely, the limit of the clutch transmission torque is small or not.
As a result, it is possible to reduce or cancel the driving force limitation at the start due to the limitation of the clutch transmission torque while protecting the clutch.

(2) The clutch changing means is a command for changing a gear ratio, and a gear change command for slidingly engaging a clutch different from the first clutch among the clutches to be engaged at the changed gear stage is used for the transmission. By outputting to the AT, the clutch for sliding engagement is changed. The target drive torque correction means is a correction torque corresponding to a change in the output torque of the transmission AT due to the shift in synchronization with the output of the shift command by the clutch changing means, and the output of the transmission AT by the shift. The target drive torque of the drive source is corrected in the direction in which the change in the value becomes smaller.

  By forcibly shifting regardless of the shift schedule, the clutch that has been slip-engaged is in a fully engaged state or a fully released state. The clutch that has been slip-engaged is cooled by oil lubrication of the transmission AT. For this reason, the wear of the clutch due to an increase in the amount of heat generation can be prevented, and the life can be extended. Moreover, it becomes possible to change reliably the clutch engaged by sliding by shifting.

Further, when changing the clutch to be engaged, the output torque of the transmission AT decreases if the input torque of the transmission AT is the same due to the forced upshift. On the other hand, the gear ratio difference torque is added to the target driving torque at the time of shifting so as not to generate a driving force step.
As a result, even if the gear ratio is changed by shifting, fluctuations in the output torque of the transmission AT can be suppressed. As a result, it is possible to suppress a sense of discomfort due to fluctuations in the output torque of the transmission AT. For example, a decrease in output torque of the transmission AT causes a stagnation of acceleration unintended by the driver, but since this can be prevented, a sense of discomfort to the driver can be reduced.

(3) When it is estimated that the clutch temperature of the clutch engaged in slip engagement is equal to or higher than a predetermined temperature, the clutch engaged in slip engagement is changed while maintaining the same gear position.
For example, a plurality of clutches are engaged at the gear position after the normal upshift. For this reason, even if the amount of heat generated by one clutch exceeds the threshold value for preventing clutch burn-in, the clutch that generates heat is cooled by oil lubrication of the transmission AT by switching to another clutch as necessary, and the same gear Can prevent clutch wear.

(4) A transmission AT is interposed in the torque transmission path from the engine to the drive wheel, and a motor is interposed in the torque transmission path between the engine and the transmission AT, and the engine and the motor are connected to the drive source. To do. The target drive torque correction means corrects the target drive torque of the motor.
By correcting the target drive torque of the motor, fluctuations in the output torque of the transmission AT with respect to the shift can be suppressed with good response.

(Modification)
(1) In the said embodiment, the case where the engine and the motor comprised the drive source was illustrated. Even when starting with only the torque of the motor or the torque of the engine, any configuration can be applied as long as the clutch is controlled by sliding engagement.
(2) In the above embodiment, the case of shifting to the second speed when changing the slip engagement clutch is illustrated, but the shifting process may be performed to the third speed or more. Further, the sliding engagement clutch may be changed during the first speed.

1 is an overall system diagram showing a rear-wheel drive hybrid vehicle according to an embodiment of the present invention. It is a figure which shows the structural example of the transmission (1st speed) which concerns on embodiment based on this invention. It is a figure which shows the structural example of the transmission (2nd speed) which concerns on embodiment based on this invention. It is a figure which shows the process in connection with the process of the drive control which concerns on embodiment based on this invention. It is a figure which shows the process of the drive control part main body which concerns on embodiment based on this invention. It is a figure which shows the process of the target engine torque calculating part which concerns on embodiment based on this invention. It is a figure which shows the process of the target clutch torque calculating part which concerns on embodiment based on this invention. It is a figure explaining the process of the target motor torque calculating part which concerns on embodiment based on this invention. It is a figure explaining the process of the target engine torque calculating part for engine driving modes which concerns on embodiment based on this invention. It is a figure explaining the process of the target clutch torque calculating part for engine driving modes which concerns on embodiment based on this invention. It is a figure explaining the process of the slip fastening process part which concerns on embodiment based on this invention. It is a figure explaining the process of the motor torque calculation part for engine driving modes which concerns on embodiment based on this invention. It is an example of the time chart which concerns on embodiment based on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Engine controller 2 Motor controller 5 Clutch controller 7 AT controller 10 Integrated controller 10A Drive control part main body 10B Target engine torque calculating part 10C Target clutch torque calculating part 10D Target motor torque calculating part 10E Target engine torque calculating part 10F for engine driving modes Driving mode target clutch torque calculation unit 10G Engine driving mode target motor torque calculation unit 10H Engagement processing unit 16 Acceleration opening sensor 17 Vehicle speed sensor AT Transmission CL1 First clutch CL2 Second clutch E Engine MG Motor Q1C Heat dissipation Q1L Predetermined Temperature Q2 Clutch temperature Q2L Predetermined temperature ΔTin Additional torque

Claims (4)

A drive control device for a vehicle capable of transmitting drive torque from a drive source to drive wheels via a transmission,
Upon detecting a start request of the vehicle, to control the drive torque of the drive source to the goals driving torque, by controlling the first clutch forming part of the transmission to the sliding engagement of the drive source Start control means for transmitting drive torque to the drive wheels;
Clutch temperature estimating means for estimating the temperature of the first clutch;
When it is determined that the clutch temperature estimated by the clutch temperature estimating means is equal to or higher than a predetermined temperature during the control of the drive torque of the drive source to the target drive torque, a command to shift up by changing the gear ratio is used regardless of the shift schedule. outputs certain upshift command, among the above within the transmission clutch, clutches that selects a clutch after different upshift to the above first clutch, and terminates the upshift in Rukoto to slip concluded the selected clutch Change means,
Synchronously with the output of the up-shift command by the clutch changing means, there is provided target drive torque correcting means for increasing the target drive torque in accordance with a change in the output torque of the transmission due to a shift. A vehicle drive control device. When it is estimated that the clutch temperature of the clutch engaged by sliding after the clutch changing means has changed from the first clutch by selection from the first clutch, it is determined that the clutch is engaged at the same shift stage. The vehicle drive control device according to claim 1, wherein a clutch to be switched is switched . A transmission is interposed in the torque transmission path from the engine to the drive wheels, a motor is interposed in the torque transmission path between the engine and the transmission, and the engine and motor are used as the driving source.
2. The braking / driving control apparatus for a vehicle according to claim 1 , wherein the target drive torque correcting means corrects the target drive torque of the motor. Upon detecting a vehicle start request, the driving torque of the driving source to control the goals driving torque, the first clutch forming part of the transmission by controlling the slipping engagement, the driving torque of the drive source transmitted to the drive wheels via the transmission,
While controlling the drive torque of the drive source to the target drive torque, if it is determined that the temperature of the first clutch is equal to or higher than a predetermined protection temperature, it is an instruction to change the gear ratio and shift up regardless of the shift schedule Output a shift command, select a clutch after an upshift different from the first clutch among the clutches in the transmission, and end the upshift by sliding and fastening the selected clutch ;
A vehicle start control method, wherein the target drive torque is increased in accordance with a change in output torque of the transmission due to a shift in synchronization with outputting the upshift command .

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