JP5239841B2 - Control device for hybrid vehicle - Google Patents

Description

  The present invention relates to a control device for a hybrid vehicle for fastening a clutch interposed between an engine and a motor when an engine fastening request for adding the engine to a motor power source is requested.

Conventionally, in a hybrid vehicle in which the output torque of the engine is transmitted to the wheels while the clutch is connected, and the output torque of the electric motor is transmitted to the wheels while the clutch is disconnected, the rotation of the clutch on the engine side When the absolute value of the difference between the number and the rotation speed of the clutch on the electric motor side becomes smaller than a predetermined value, the clutch is switched from the disconnected state to the connected state (see, for example, Patent Document 1).
JP 2007-320388

  However, in the conventional hybrid vehicle control device, if there is a difference between the engine-side clutch rotational speed and the motor-side clutch rotational speed, an unexpected behavior of the driver may occur in the vehicle in some cases. There was a problem that there was a possibility of giving a strange feeling to the person.

  The present invention has been made paying attention to the above-mentioned problem. When an engine fastening request for adding an engine to a motor power source is requested, the vehicle has a behavior that obtains a deceleration feeling intended by the driver. An object of the present invention is to provide a control device for a hybrid vehicle capable of reducing the above.

In order to achieve the above object, the hybrid vehicle control device of the present invention has an engine, a motor, a clutch interposed between the engine and the motor, and drive wheels in a drive system, Clutch engagement control means is provided for performing engagement control of the clutch in the released state when an engine engagement request is made to shift from a traveling state using the motor as a power source to a traveling state where the engine is added to the power source.
In this hybrid vehicle control device, when the clutch engagement control means is at the time of an engine engagement request and decelerates using the engine friction after the clutch engagement , the motor rotation The engine rotational speed control is executed with the value obtained by subtracting the target rotational speed difference threshold value from the speed as the target engine rotational speed, and the engine side clutch rotational speed is lower than the motor side clutch rotational speed . The engine speed is switched from the rotational speed control to the torque control, the engine is operated with the required driving force, and the clutch is engaged.

Therefore, in the hybrid vehicle control device of the present invention, when the engine is requested to be engaged and the vehicle is decelerated using the engine friction after the clutch is engaged, the clutch engagement control means determines that there is an engine engagement request. Then, engine speed control is executed with the value obtained by subtracting the target rotational speed difference threshold value from the motor rotational speed as the target engine rotational speed. When the engine-side clutch rotational speed is lower than the motor-side clutch rotational speed, the engine is switched from rotational speed control to torque control, the engine is operated with the required driving force, and the clutch is engaged. Done.
For example, when the engine is decelerated using the engine friction after the clutch is engaged, if the clutch is engaged with the engine-side clutch rotational speed being higher than the motor-side clutch rotational speed, the engine moves the motor in the driving direction. This means that the vehicle is rotated and acceleration behavior unintended by the driver appears in the vehicle. On the other hand, if the clutch is engaged in a state where the engine-side clutch rotational speed is lower than the motor-side clutch rotational speed, the engine will decrease the rotational speed of the motor, and the deceleration behavior intended by the driver will be reduced. Comes out to the vehicle.
As a result, it is possible to reduce the sense of incongruity given to the driver by causing the vehicle to behave in a manner that obtains a deceleration feeling intended by the driver when an engine fastening request is made to add the engine to the motor power source.

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

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

  As shown in FIG. 1, the drive system of the FR hybrid vehicle in the first embodiment includes an engine Eng, a flywheel FW, a first clutch CL1 (clutch), a motor / generator MG (motor), and a second clutch CL2. Automatic transmission AT, propeller shaft PS, differential DF, left drive shaft DSL, right drive shaft DSR, left rear wheel RL (drive wheel), and right rear wheel RR (drive wheel), Have. Note that FL is the left front wheel and FR is the right front wheel.

  The engine Eng is a gasoline engine or a diesel engine, and engine start control, engine stop control, and throttle valve opening control are performed based on an engine control command from the engine controller 1. The engine output shaft is provided with a flywheel FW.

  The first clutch CL1 is a clutch interposed between the engine Eng and the motor / generator MG. The first clutch CL1 is operated by the first clutch hydraulic unit 6 based on a first clutch engagement control command from the first clutch controller 5. Engagement / release is controlled including the half-clutch state by the generated first clutch engagement control hydraulic pressure. As the first clutch CL1, for example, a dry single-plate clutch whose engagement / release is controlled by a hydraulic actuator 14 having a piston 14a is used.

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

  The second clutch CL2 is a clutch interposed between the motor / generator MG and the left and right rear wheels RL, RR. Based on the second clutch engagement control command from the AT controller 7, the second clutch hydraulic unit By the control hydraulic pressure created by 8, the engagement / release is controlled including slip engagement and slip release. As the second clutch CL2, for example, a wet multi-plate clutch or a wet multi-plate brake capable of continuously controlling the oil flow rate and hydraulic pressure with a proportional solenoid is used. The first clutch hydraulic unit 6 and the second clutch hydraulic unit 8 are built in an AT hydraulic control valve unit CVU attached to the automatic transmission AT.

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

  The hybrid drive system of the first embodiment includes an electric vehicle travel mode (hereinafter referred to as “EV mode”), a hybrid vehicle travel mode (hereinafter referred to as “HEV mode”), and a CL2 slip engagement travel mode (hereinafter referred to as “ It has a driving mode such as “WSC mode”.

  The “EV mode” is a mode in which the first clutch CL1 is opened and the vehicle travels only with the power of the motor / generator MG. The “HEV mode” is a mode in which the first clutch CL1 is engaged and the vehicle travels in any one of the engine travel mode, the motor assist travel mode, and the travel power generation mode. The “WSC mode” is, for example, a low vehicle speed range including a vehicle stop when starting from “EV mode”, starting from “HEV mode”, or traveling on an uphill road in “HEV mode”. The second clutch CL2 is brought into the slip engagement state, and the clutch transmission capacity is controlled so that the clutch transmission torque passing through the second clutch CL2 becomes the required driving torque determined according to the vehicle state and the driver operation. It is a running mode. “WSC” is an abbreviation for “Wet Start Clutch”.

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

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

  The motor controller 2 inputs information from the resolver 13 that detects the rotor rotational position of the motor / generator MG, a target MG torque command and a target MG rotational speed command from the integrated controller 10, and other necessary information. Then, a command for controlling the motor operating point (Nm, Tm) of the motor / generator MG is output to the inverter 3. The motor controller 2 monitors the battery SOC representing the charge capacity of the battery 4, and this battery SOC information is used as control information for the motor / generator MG and is integrated via the CAN communication line 11. 10 is supplied.

  The first clutch controller 5 inputs sensor information from the first clutch stroke sensor 15 that detects the stroke position of the piston 14a of the hydraulic actuator 14, a target CL1 torque command from the integrated controller 10, and other necessary information. . Then, a command for controlling engagement / disengagement of the first clutch CL1 is output to the first clutch hydraulic unit 6 in the AT hydraulic control valve unit CVU.

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

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

  The integrated controller 10 manages the energy consumption of the entire vehicle and has a function for running the vehicle with the highest efficiency. The integrated controller 10 detects a motor rotation speed Nm, and other sensors and switches 22. Necessary information and the like are input via the CAN communication line 11. The target engine torque command to the engine controller 1, the target MG torque command and the target MG speed command to the motor controller 2, the target CL1 torque command to the first clutch controller 5, the target CL2 torque command to the AT controller 7, and the brake controller 9 Regenerative cooperative control command is output.

  FIG. 2 is a control block diagram illustrating arithmetic processing executed by the integrated controller 10 of the FR hybrid vehicle to which the control device of the first embodiment is applied. FIG. 3 is a diagram illustrating an EV-HEV selection map used when performing a mode selection process in the integrated controller 10 of the FR hybrid vehicle to which the control device of the first embodiment is applied. FIG. 4 is a diagram illustrating a target charge / discharge amount map used when battery charge control is performed by the integrated controller 10 of the FR hybrid vehicle to which the control device of the first embodiment is applied. Hereinafter, based on FIGS. 2-4, the arithmetic processing performed in the integrated controller 10 of Example 1 is demonstrated.

  As shown in FIG. 2, the integrated controller 10 includes a target driving force calculation unit 100, a mode selection unit 200, a target charge / discharge calculation unit 300, and an operating point command unit 400.

  The target driving force calculation unit 100 calculates a target driving force tFoO from the accelerator opening APO and the vehicle speed VSP using the target driving force map.

  The mode selection unit 200 uses the EV-HEV selection map shown in FIG. 3 to select “EV mode” or “HEV mode” as the target travel mode from the accelerator opening APO and the vehicle speed VSP. However, if the battery SOC is equal to or lower than the predetermined value, the “HEV mode” is forcibly set as the target travel mode. Further, when starting from the “EV mode” or “HEV mode”, the “WSC mode” is selected as the target travel mode until the vehicle speed VSP reaches the first set vehicle speed VSP1.

  The target charge / discharge calculation unit 300 calculates the target charge / discharge power tP from the battery SOC using the target charge / discharge amount map shown in FIG.

  In the operating point command unit 400, based on input information such as the accelerator opening APO, the target driving force tFoO, the target travel mode, the vehicle speed VSP, the target charge / discharge power tP, etc., the target engine torque is set as the operating point reaching target. And target MG torque, target MG rotation speed, target CL1 torque, and target CL2 torque. Then, the target engine torque command, the target MG torque command, the target MG rotational speed command, the target CL1 torque command, and the target CL2 torque command are output to the controllers 1, 2, 5, and 7 via the CAN communication line 11.

  FIG. 5 is a flowchart showing the flow of the first clutch engagement control process when the engine engagement request is executed by the integrated controller 10 of the first embodiment (clutch engagement control means). Hereinafter, each step of the flowchart of FIG. 5 will be described.

  In step S101, it is determined whether or not there is an engine engagement request for engaging the first clutch CL1 and adding the engine Eng to the motor power source. If YES (engine engagement requested), the process proceeds to step S102, and NO (engine engagement) If no request, go to the end.

In step S102, following the determination that there is an engine fastening request in step S101, engine speed control is executed with the following target value (target engine speed), and the process proceeds to step S103.
・ When requesting positive drive after the engine is engaged (Fig. 6)
⇒ Motor rotation speed + β (where β> 0) = Target engine rotation speed ・ When you want to request negative drive after the engine is engaged (Fig. 7)
⇒Motor rotational speed−β (where β> 0) = target engine rotational speed Here, the target rotational speed difference threshold β is the noise of the engine rotational speed sensor 12 and the motor rotational speed sensor 21 and the stability of rotational speed feedback control. Taking into account communication delays between ECUs and ECUs, etc., experimentally obtain the smallest possible difference in rotational speed so that the difference between the engine rotational speed and motor rotational speed is positive or negative.

In step S103, following execution of the engine speed control in step S102, the engine speed detection value from the engine speed sensor 12 has reached the engagement permission rotation speed in consideration of the engagement permission determination threshold for the target engine rotation speed. In the case of YES (reaching the fastening permission rotational speed), the process proceeds to step S104, and in the case of NO (not reaching the fastening permission rotational speed), the process returns to step S102.
Here, the engagement permission rotation speed is obtained by adding a engagement permission determination threshold value to the target engine rotation speed when a positive drive request is made after the engine is engaged. On the other hand, when it is desired to make a negative drive request after the engine is engaged, it is obtained by subtracting the engagement permission determination threshold value from the target engine speed.

In step S104, following the determination that the engagement-permitted rotational speed has been reached in step S103, or the determination that it has not continued for the set time in step S105, the engine speed detection value from the engine speed sensor 12 is determined. , (Target engine rotational speed-γ) to (target engine rotational speed + γ) to determine whether the value is within the range, if YES (target engine rotational speed ± γ range), proceed to step S105, If NO (outside the target engine speed ± γ range), the process returns to step S102.
Here, the fastening start rotational speed allowable value ± γ is determined in consideration of noise of the engine rotational speed sensor 12 and the motor rotational speed sensor 21 and stability of the rotational speed feedback control.

  In step S105, following the determination in step S104 that the target engine rotational speed is within the range of γ, it is determined whether or not the state where the engagement start engine rotational speed condition is satisfied continues for a set time or longer, and YES (continuous engagement start) If the condition is satisfied, the process proceeds to step S106, and if NO (the engagement start continuation condition is not satisfied), the process returns to step S104.

  In step S106, following the determination that the engagement start continuation condition is satisfied in step S105, or the determination that the clutch rotational speed difference is not sufficiently small in step S108, the engine Eng is operated with the required driving force, and step S107. Proceed to

In step S107, following the engine operation with the required driving force in step S106, the first clutch CL1 is engaged with a torque capacity equivalent to (engine required driving torque + addition torque α), and the process proceeds to step S108.
Here, the additional torque α is determined at the same ratio with respect to the engine required drive torque. The ratio is derived experimentally. For example, if the engine required drive torque after clutch engagement is +100 [Nm] and the ratio is set to [10%], the first clutch CL1 is engaged at 100 + 100 * 10% = 110 [Nm] To do.

  In step S108, following the engagement at the engine required drive torque + α in step S107, it is determined whether or not the clutch rotational speed difference of the first clutch CL1 is sufficiently small, and YES (the clutch rotational speed difference is sufficiently small). If this is the case, the process proceeds to step S109. If NO (the clutch rotational speed difference is not sufficiently small), the process returns to step S107.

In step S109, following the determination that the clutch rotational speed difference is sufficiently small in step S108, the first clutch CL1 is added to the engine required drive torque, the torque α and the engagement margin torque are completely engaged, and the process proceeds to the end.
Here, the engagement margin torque is set as a torque that maintains the fully engaged state without slipping the first clutch CL1 even if the engine Eng and the motor / generator MG have torque fluctuations.

Next, the operation will be described.
The functions of the hybrid vehicle control device of the first embodiment are as follows: “Overview / problems of the prior art”, “First clutch engagement control operation when requesting positive drive after engine engagement”, “Negative drive after engine engagement” The description will be divided into “first clutch engagement control action”.

[Overview / problems of conventional technology]
In a system having an engine, a motor, and a clutch between them, in JP 2007-320388 A, when a request for switching the clutch from a disconnected state to a connected state occurs, the rotational speed of the engine-side rotating element of the clutch is set to the motor side. The engine output torque is controlled in accordance with the rotational speed difference between them so as to approach the rotational speed of the rotating elements. The engine output torque is changed stepwise according to the range of the rotational speed difference. A technique is described in which, when the rotational speeds of both rotary elements become substantially the same, supply of pressure oil from the hydraulic device to the clutch is started so that the clutch is switched from the disconnected state to the connected state.

  However, when it is desired to drive the engine positively after the engine is engaged, if the clutch is engaged with the engine rotational speed being smaller than the motor rotational speed, the load torque applied to the engine shaft is switched, and a shock is transmitted from the engine mount, or the motor When the shaft and the drive wheel are directly connected via a gear, torque in the direction opposite to the required drive force may be transmitted on the drive shaft.

  On the other hand, Japanese Patent Laid-Open No. 2000-23311 describes a technique for starting the engagement of a clutch when the engine speed exceeds the motor speed. However, the control at the time of deceleration request is not discussed. If the engine speed exceeds the motor speed at the time of deceleration request, a positive driving force may be output to the drive shaft against the user's intention.

  In order to eliminate the torque step, it is preferable to tighten after eliminating the rotational speed difference as much as possible, but considering the fact that the engine and motor speed sensors are generally different and the communication delay between the ECUs taken into account, the speed difference is completely different. It is assumed that it is practically difficult to control at 0.

[First clutch engagement control action when requesting positive drive after engine engagement]
FIG. 8 is a time chart showing characteristics of the engine rotational speed, the motor rotational speed, the clutch torque, the engine torque, and the engine load torque when a positive drive request is made after the engine is engaged in the first embodiment. Hereinafter, based on FIG. 5 and FIG. 8, the first clutch engagement control action when a positive drive request is desired after the engine is engaged will be described.

  When there is an engine fastening request and it is desired to request a positive drive after the engine is fastened, the process proceeds from step S101 to step S102 to step S103 in the flowchart of FIG. 5, where the engine speed detection value is the fastening start permission speed in step S103. In step S102, engine rotational speed control is executed with the motor rotational speed + β (where β> 0) as the target engine rotational speed.

  If it is determined in step S103 that the engine speed detection value has reached the engagement start permission speed, the process proceeds from step S103 to step S104 to step S105, and the engine speed detection value is set to the target engine speed ± γ. It is determined whether or not the state existing in the range continues for a set time or longer. If it is determined in step S104 that the detected engine speed value is outside the range of the target engine speed ± γ, the process returns to step S102 and engine speed control is executed again.

  When the engine rotation speed continuation condition, which is the engagement start condition, is satisfied, the process proceeds from step S105 to step S106 → step S107 → step S108. In step S108, it is determined that the clutch rotation speed difference of the first clutch CL1 is sufficiently small. In step S106, the engine Eng is operated with the required driving force, and in step S107, the first clutch CL1 is engaged in an amount corresponding to (engine required driving torque + addition torque α).

  If it is determined in step S108 that the clutch rotational speed difference of the first clutch CL1 is sufficiently small, the process proceeds from step S108 to step S109. In step S109, the first clutch CL1 is added to the engine required drive torque. Fully tightened with α and fastening margin torque.

  That is, when it is desired to request a positive drive after the engine is engaged, if there is an engine engagement request at time t1 in FIG. 8, the detected engine speed reaches the engagement start permission speed from time t1 (time t2), and further the target engine The engine speed control is executed until time t3 when the set time elapses in a state where the rotational speed is within the range of ± γ. That is, the engine torque is kept low by an amount that gradually decreases the engine speed.

  When the engagement start time t3 is reached, the engine torque is restored to the required drive torque, and the clutch torque applied to the first clutch CL1 is added to the engine required drive torque and added to the torque α. By this control, the engine rotational speed having a value higher than the motor rotational speed gradually falls from the target engine rotational speed range and converges to the motor rotational speed. The gradient dw / dt of the engine speed at this time approximates a value obtained by dividing the additional torque α by the engine inertia I.

  Then, when the clutch rotational speed difference becomes sufficiently small at time t4, the clutch torque to the first clutch CL1 is set to the torque required by adding the engine demanded drive torque and the engagement margin torque, and the first clutch CL1 is turned on. Fully conclude.

As described above, in the first embodiment, when it is desired to request a positive drive after the engine is engaged, the first clutch CL1 is engaged in a state where the engine rotational speed exceeds the motor rotational speed.
For example, if the engine-side clutch rotation speed is lower than the motor-side clutch rotation speed when the engine is to be driven positively after the engine is engaged, the engine-side clutch that has been driven to rotate by the engine is rotated by the motor. As a result, the sign of the load torque applied to the shaft of the engine is reversed. In this way, if the load torque applied to the engine shaft is reversed, the engine side clutch runs idle for the amount of backlash from the engine to the engine side clutch, and a shock occurs when the backlash disappears. .
In contrast, in the first embodiment, the first clutch CL1 is engaged in a state where the engine rotational speed exceeds the motor rotational speed. Therefore, after the clutch is engaged, the engine-side clutch may be rotationally driven by the motor / generator MG. The direction of the load torque applied to the engine shaft does not reverse before and after the fastening, and the shock transmitted to the engine mount and the drive shaft at the time of fastening is reduced.

In the first embodiment, even if it is determined that the detected value of the engine speed has reached the engagement start permission speed, the condition that the engine engine speed is within the target engine speed ± γ range continues for a set time or longer. As a result, the engagement of the first clutch CL1 is started.
That is, both the engine Eng and the motor / generator MG vary in rotational speed due to sensor noise and feedback control. Even if this fluctuation occurs, the engine rotational speed and the motor rotational speed are not reversed. A predetermined range is defined.
For this reason, when accelerating using the driving force from the engine Eng after the clutch is engaged, even if there is variation due to sensor noise or control, the engine-side clutch speed is the same as the motor-side clutch speed. It is possible to prevent the clutch from being engaged in a higher state.

In the first embodiment, when the engagement start condition is satisfied, the engine Eng is switched from the rotational speed control to the torque control, and the first clutch CL1 is output with a torque capacity equivalent to the engine required drive torque added to the torque α. I am doing so.
Therefore, by adding the additional torque α to the engine required drive torque, this additional torque α becomes the engine load torque, and the engine rotational speed converges with a gentle downward gradient with respect to the motor rotational speed. Suppressing the occurrence of the driver does not give the driver a sense of incongruity.

In the first embodiment, when the rotational speed difference of the first clutch CL1 (= the difference between the engine rotational speed and the motor rotational speed) becomes sufficiently small, the addition torque α and the engagement margin torque are added to the engine required drive torque. The first clutch CL1 is completely engaged.
Therefore, when the first clutch CL1 is completely engaged, there is no occurrence of a shock unlike when the large rotational speed difference of the first clutch CL1 is made zero at a stretch, and the first clutch CL1 can be smoothly shifted to complete engagement. .

[First clutch engagement control when negative drive is desired after engine engagement]
FIG. 9 is a time chart showing characteristics of the engine rotation speed, the motor rotation speed, the clutch torque, the engine torque, and the engine load torque when it is desired to perform negative driving after the engine is engaged in the first embodiment. FIG. 10 is a time chart showing characteristics of the engine rotation speed, the motor rotation speed, the clutch torque, the engine torque, and the engine load torque when the tool torque is requested after the engine is engaged in the comparative example. Hereinafter, based on FIGS. 5, 9, and 10, the first clutch engagement control operation when negative driving is desired after the engine is engaged will be described.

  When there is an engine fastening request and it is desired to perform negative driving after the engine is fastened, the process proceeds from step S101 to step S102 to step S103 in the flowchart of FIG. 5, where the engine speed detection value becomes the fastening start permission speed in step S103. Until it reaches, in step S102, engine speed control is performed with the motor rotational speed −β (where β> 0) as the target engine rotational speed.

  If it is determined in step S103 that the engine speed detection value has reached the engagement start permission speed, the process proceeds from step S103 to step S104 to step S105, and the engine speed detection value is set to the target engine speed ± γ. It is determined whether or not the state existing in the range continues for a set time or longer. If it is determined in step S104 that the detected engine speed value is outside the range of the target engine speed ± γ, the process returns to step S102 and engine speed control is executed again.

  When the engine rotation speed continuation condition, which is the engagement start condition, is satisfied, the process proceeds from step S105 to step S106 → step S107 → step S108. In step S108, it is determined that the clutch rotation speed difference of the first clutch CL1 is sufficiently small. In step S106, the engine Eng is operated with the required driving force, and in step S107, the first clutch CL1 is engaged in an amount corresponding to (engine required driving torque + addition torque α).

  If it is determined in step S108 that the clutch rotational speed difference of the first clutch CL1 is sufficiently small, the process proceeds from step S108 to step S109. In step S109, the first clutch CL1 is added to the engine required drive torque. Fully tightened with α and fastening margin torque.

  That is, when it is desired to perform negative driving after the engine is engaged, if there is an engine engagement request at time t1 in FIG. 9, the detected engine speed reaches the engagement start permission speed from time t1 (time t2), and further, the target engine rotation The engine speed control is executed until time t3 when the set time elapses in a state where the speed is within the range of ± γ. That is, the negative engine torque is increased by an amount that gradually increases the engine speed.

  Then, when the engagement start time t3 is reached, the negative engine torque is restored to the required drive torque, and the clutch torque to the first clutch CL1 is the engine required drive torque (the amount of torque that has moved the negative torque to the positive side). ) Is added to the torque α to obtain the torque. By this control, the engine rotational speed having a value lower than the motor rotational speed gradually increases from the target engine rotational speed region and converges to the motor rotational speed. The gradient dw / dt of the engine speed at this time approximates a value obtained by dividing the additional torque α by the engine inertia I.

  Then, when the clutch rotational speed difference becomes sufficiently small at time t4, the clutch torque to the first clutch CL1 is set to the torque required by adding the engine demanded drive torque and the engagement margin torque, and the first clutch CL1 is turned on. Fully conclude.

As described above, in Example 1, when it is desired to request deceleration using engine friction after the engine is engaged, the first clutch CL1 is engaged in a state where the engine rotation speed is lower than the motor rotation speed.
For example, if you want to request negative torque after the engine is engaged, if the engine clutch speed is higher than the motor clutch speed, the engine will rotate the motor in the driving direction. As shown in the engine load torque characteristic of 10, the sign of the load torque applied to the engine shaft is reversed. Thus, when the load torque applied to the shaft of the engine is reversed in the positive and negative directions (A portion in FIG. 10), the shock is transmitted to the engine mount, and if the motor is connected to the drive shaft, the shock is also applied to the drive shaft. It will be transmitted. Furthermore, when the motor is rotated in the driving direction by the engine, a feeling of acceleration is produced, which not only impairs the feeling of deceleration, but also makes the driver feel uncomfortable.
On the other hand, in the first embodiment, the first clutch CL1 is engaged in a state where the engine rotation speed is lower than the motor rotation speed. Therefore, after the clutch is engaged, the motor / generator MG is driven to rotate in the driving direction by the engine Eng. As shown in the engine load torque characteristics of FIG. 9, the direction of the load torque applied to the engine shaft does not reverse before and after the fastening, and the shock transmitted to the engine mount and the drive shaft during the fastening is reduced. A feeling of deceleration can be obtained by rotating the motor / generator MG in the braking direction by Eng.

In the first embodiment, even if it is determined that the detected value of the engine speed has reached the engagement start permission speed, the condition that the engine engine speed is within the target engine speed ± γ range continues for a set time or longer. As a result, the engagement of the first clutch CL1 is started.
That is, both the engine Eng and the motor / generator MG vary in rotational speed due to sensor noise and feedback control. Even if this fluctuation occurs, the engine rotational speed and the motor rotational speed are not reversed. A predetermined range is defined.
For this reason, when the engine Eng friction is decelerated after the clutch is engaged, the engine-side clutch speed is higher than the motor-side clutch speed, even if there are variations due to sensor noise or control. In this state, the clutch can be prevented from being engaged.

In the first embodiment, when the engagement start condition is satisfied, the engine Eng is switched from the rotational speed control to the torque control, and the first clutch CL1 is output with a torque capacity equivalent to the engine required drive torque added to the torque α. I am doing so.
Therefore, by adding the additional torque α to the engine required drive torque, this additional torque α becomes the engine load torque, and the engine rotational speed converges with a gentle rising gradient with respect to the motor rotational speed. Suppressing the occurrence of the driver does not give the driver a sense of incongruity. The other actions are the same as the first clutch fastening control action when it is desired to request a positive drive after the engine is fastened.

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

  (1) The drive system includes an engine Eng, a motor (motor / generator MG), a clutch (first clutch CL1) interposed between the engine Eng and the motor, and drive wheels (left and right rear wheels RL, RR), and a clutch engagement control for performing the engagement control of the clutch in an open state at the time of an engine engagement request for transition from a traveling state using the motor as a power source to a traveling state in which the engine Eng is added to the power source In the control device for a hybrid vehicle (FR hybrid vehicle) provided with the means, the clutch engagement control means (FIG. 5) is at the time of engine engagement request and decelerates using the friction of the engine Eng after clutch engagement. The clutch is engaged in a state where the engine-side clutch rotational speed is lower than the motor-side clutch rotational speed. For this reason, at the time of the engine fastening request | requirement which adds an engine to a motor motive power source, the behavior which obtains the driver | operator's intention of the deceleration feeling is produced in a vehicle, and reduction of the uncomfortable feeling given to a driver | operator can be aimed at.

  (2) The clutch engagement control means (FIG. 5) is an engine engagement request, and when the vehicle is driven by the driving force of the engine Eng after engagement of the clutch, the engine-side clutch rotation speed is the motor-side clutch rotation speed. The clutch (first clutch CL1) is engaged at a higher rotational speed. For this reason, at the time of the engine fastening request | requirement which adds an engine to a motor power source, the behavior which obtains the driver | operator's intended acceleration feeling is produced in a vehicle, and the discomfort given to a driver | operator can be reduced.

  (3) When the clutch engagement control means (FIG. 5) keeps the difference between the engine-side clutch rotational speed and the motor-side clutch rotational speed within a set rotational speed difference range for a set time or more, Engagement of (first clutch CL1) is started. For this reason, when the clutch (first clutch CL1) is started in response to the engine engagement request, even if there is a variation due to sensor noise or feedback control, the set engine rotation speed and the motor clutch rotation speed are set. Difference can be ensured.

  (4) The clutch engagement control means (FIG. 5) operates the engine Eng with the required drive torque when the engagement start condition of the clutch (first clutch CL1) is satisfied, and adds the torque to the engine required drive torque. Engagement of the clutch is started at a torque capacity equivalent to α. For this reason, the engine-side clutch rotational speed can be converged to the motor-side clutch rotational speed without occurrence of a shock with a smooth gradient of the rotational speed.

  (5) When the clutch rotational speed difference becomes sufficiently small after the clutch engagement control means (FIG. 5) has started the engagement of the clutch at a torque capacity equivalent to the engine required drive torque plus the additional torque α, the engine The clutch (first clutch CL1) is completely engaged at a torque capacity equivalent to the required drive torque plus the torque α and the engagement margin torque. For this reason, it is possible to meet the engine fastening request for adding the engine Eng to the motor power source while suppressing the fastening shock of the clutch (first clutch CL1).

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

  In the first embodiment, the input side of the first clutch CL1 is directly connected to the engine Eng, the output side is directly connected to the motor / generator MG, the engine-side clutch rotational speed matches the engine rotational speed, and the motor-side clutch rotational speed is An example that matches the motor rotation speed is shown. However, the input side of the first clutch CL1 may be indirectly connected to the engine Eng, or the output side may be indirectly connected to the motor / generator MG. That is, the engine-side clutch rotational speed means the rotational speed of the clutch member connected to the engine side, and the motor-side clutch rotational speed means the rotational speed of the clutch member connected to the motor side.

  In the first embodiment, the application example to the FR hybrid vehicle in which the first clutch is interposed between the engine and the motor / generator and the second clutch is interposed between the motor / generator and the driving wheel is shown. However, the second clutch can also be applied to a hybrid vehicle that is set independently between the motor / generator and the transmission or between the transmission and the drive wheels. Furthermore, the present invention can be applied to various types of hybrid vehicles provided with a clutch called an engine clutch between the engine and the motor. In short, a hybrid vehicle that has an engine, a motor, a clutch interposed between the engine and the motor, and a drive wheel in the drive system, and that controls the engagement of the opened clutch when the engine is requested to be engaged. Can be applied.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an overall system diagram showing an FR hybrid vehicle (an example of a vehicle) by rear wheel drive to which a hybrid vehicle control device of Embodiment 1 is applied. It is a control block diagram which shows the arithmetic processing performed in the integrated controller 10 of the FR hybrid vehicle to which the control apparatus of Example 1 was applied. It is a figure which shows the EV-HEV selection map used when performing the mode selection process with the integrated controller 10 of the FR hybrid vehicle to which the control apparatus of Example 1 is applied. It is a figure which shows the target charging / discharging amount map used when performing a battery charging / discharging process with the integrated controller 10 of the FR hybrid vehicle to which the control apparatus of Example 1 was applied. It is a flowchart which shows the flow of the 1st clutch fastening control process at the time of the engine fastening request | requirement performed in the integrated controller 10 of Example 1. FIG. It is explanatory drawing which shows the setting of the target rotational speed difference threshold value + β used in the first clutch engagement control when an engine engagement request is made and a positive drive request is made after the engine is engaged. It is explanatory drawing which shows the setting of the target rotational speed difference threshold value -β used in the first clutch engagement control when an engine engagement request is made and negative driving is desired after the engine is engaged. 3 is a time chart showing characteristics of an engine speed, a motor speed, a clutch torque, an engine torque, and an engine load torque when a positive drive request is made after the engine is engaged in the first embodiment. 3 is a time chart showing characteristics of an engine speed, a motor speed, a clutch torque, an engine torque, and an engine load torque when negative driving is desired after the engine is engaged in the first embodiment. It is a time chart which shows each characteristic of engine rotation speed, motor rotation speed, clutch torque, engine torque, and engine load torque at the time of connecting from forward rotation when a component torque is requested after engine tightening in a comparative example.

Explanation of symbols

Eng engine
MG motor / generator (motor)
CL1 1st clutch (clutch)
CL2 2nd clutch
RL Left rear wheel (drive wheel)
RR Right rear wheel (drive wheel)
DESCRIPTION OF SYMBOLS 1 Engine controller 2 Motor controller 3 Inverter 4 Battery 5 1st clutch controller 6 1st clutch hydraulic unit 7 AT controller 8 2nd clutch hydraulic unit 9 Brake controller 10 Integrated controller 12 Engine rotational speed sensor 21 Motor rotational speed sensor

Claims (5)

The drive system includes an engine, a motor, a clutch interposed between the engine and the motor, and a drive wheel.
A hybrid vehicle control device comprising clutch engagement control means for performing engagement control of the clutch in an open state when an engine engagement request is made to shift from a traveling state using the motor as a power source to a traveling state where the engine is added to the power source. In
The clutch fastening control means is configured to set a target rotational speed difference threshold value from the motor rotational speed when it is determined that the engine fastening request is present when the engine fastening request is made and the engine friction is reduced after the clutch is engaged. The engine speed control is executed with the subtracted value as the target engine speed, and the engine is switched from the speed control to the torque control when the engine-side clutch speed is lower than the motor-side clutch speed. A control apparatus for a hybrid vehicle , wherein the engine is operated with a required driving force and the clutch is engaged. In the hybrid vehicle control device according to claim 1,
The clutch fastening control means adds a target rotational speed difference threshold value from the motor rotational speed when it is determined that there is an engine fastening request when the engine is driven by the driving force of the engine after the clutch is requested. The engine rotational speed control is executed with the value as the target engine rotational speed, and the engine is switched from rotational speed control to torque control when the engine-side clutch rotational speed is higher than the motor-side clutch rotational speed. A control apparatus for a hybrid vehicle , wherein the engine is operated with a required driving force and the clutch is engaged. In the hybrid vehicle control device according to claim 1 or 2,
The clutch engagement control means, as a condition that has continued the state where the difference in clutch rotational speed of the clutch rotational speed and the motor side of the engine side is kept in the set rotation speed difference range setting time or longer, the clutch The hybrid vehicle control device is characterized in that the fastening of the vehicle is started. In the hybrid vehicle control device according to claim 3,
When the clutch engagement start condition is satisfied, the clutch engagement control unit operates the engine with the required drive torque, and starts engagement of the clutch with a torque capacity equivalent to the engine required drive torque added to the torque. A hybrid vehicle control device. In the hybrid vehicle control device according to claim 4,
When the clutch rotational speed difference becomes sufficiently small after the clutch engagement control means starts engaging the clutch with a torque capacity equivalent to the engine requested drive torque plus the added torque, the clutch engagement control means is engaged with the engine requested drive torque. A control apparatus for a hybrid vehicle, wherein the clutch is completely engaged at a torque capacity equivalent to a margin torque.

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