JP5228340B2 - Control device for hybrid vehicle - Google Patents

Description

  The present invention relates to a control device for a hybrid vehicle drive device that obtains drive force from an engine and a motor generator.

Conventionally, in a hybrid vehicle, a technique for reducing a shift shock by rotating feedback control of a motor generator so that an input rotation speed of an automatic transmission becomes a target rotation speed during an inertia phase is disclosed (for example, Patent Documents). 1).
Japanese Patent Laid-Open No. 10-257610

  However, in the above prior art, the actual rotational speed of the motor generator is made to follow the target rotational speed by the rotational feedback control. Therefore, if the torque of the motor generator is smaller than the engine torque, the target rotational speed can be obtained only by the torque of the motor generator. There was a problem that could not follow.

  The present invention has been made paying attention to the above-mentioned problem, and the object of the present invention is to drive a vehicle that ensures follow-up to the target rotational speed even when the torque of the motor generator is smaller than the engine torque. It is to provide a control device for the apparatus.

In order to achieve the above object, in the present invention, a motor generator connected to an engine, a stepped automatic transmission that is connected to the motor generator at an input shaft and achieves a predetermined shift speed by fastening a friction engagement element; In a control apparatus for a hybrid vehicle comprising: a target rotational speed calculating means for calculating a target input shaft rotational speed of the stepped automatic transmission at the time of shifting based on a shift instruction; and an output torque of the motor generator at the time of shifting Feedback control means for performing feedback control so that the rotational speed of the input shaft follows the target input shaft rotational speed, and during the feedback control of the output torque of the motor generator at the time of shifting, the accelerator opening of the engine a substantial torque output side rotation speed of the input shaft to follow the target input shaft rotational speed Feedforward control means for feed-forward control, was to have.

  Therefore, even if the torque of the motor generator is smaller than the engine torque, it is possible to provide a control device for a vehicle drive device that ensures followability to the target rotational speed.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS The best mode for realizing a control device for a vehicle drive device according to the present invention will be described below based on an embodiment shown in the drawings.

[System configuration]
FIG. 1 is a system diagram of the hybrid vehicle of the present application. The hybrid vehicle of the present application includes an engine E, a motor generator MG, a start clutch CL1, an automatic transmission AT, a left rear wheel RL (drive wheel), and a right rear wheel RR (drive wheel). Note that FL is the left front wheel and FR is the right front wheel.

  The engine E is a gasoline engine or a diesel engine, and based on a control command from the engine controller 1, the valve opening of the throttle valve and the like are controlled.

  The start clutch CL1 is interposed between the engine E and the motor generator MG, and is engaged / released by the start clutch hydraulic unit 6 based on a control command from the start clutch controller 5.

  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 rotor that is an output shaft is connected to an input shaft IN of an automatic transmission AT. At the time of driving, it is controlled by the inverter 3 </ b> A of the power control unit 3 based on a control command from the motor controller 2.

  The motor generator MG functions as an electric motor that is driven to rotate by receiving power supplied from the battery 4 (power storage device). Further, when rotating by an external force, it functions as a generator and can charge the battery 4.

  The power control unit 3 includes an inverter 3A, a high voltage circuit 3b, and a DC / DC converter 3c. Inverter 3A is a semiconductor switching element that converts the direct current of battery 4 into a three-phase alternating current and outputs it to motor generator MG, and converts the three-phase alternating current from motor generator MG into a direct current and outputs it to battery 4.

  The high-power circuit 3b is disposed between the battery 4, the inverter 3A, and the DC / DC converter 3c, and interrupts the flow of power by a relay provided therein. The DC / DC converter 3c steps down the voltage of the battery 4 and supplies power to the auxiliary battery 25 (power source for lighting, display, auxiliary equipment, etc.).

  The automatic transmission AT is a stepped transmission that automatically changes the gear position according to the vehicle speed, the accelerator opening, etc., and is connected to the rotor of the motor generator MG via the input shaft IN and via the output shaft OUT. Connect to left and right rear wheels RL, RR.

[Driving mode]
The hybrid vehicle of the present application has two driving modes, EV mode (running only with the driving force of the motor generator MG) and HEV mode (using driving force of the motor generator MG and the engine E) according to the engagement / release state of the start clutch CL1. Have.

(EV mode)
When the starting clutch CL1 is in the released state, the driving force of the engine E is not transmitted to the automatic transmission AT, and the vehicle enters an EV mode in which only the power of the motor generator MG runs.

(HEV mode)
When the starting clutch CL1 is in the engaged state, the driving force of the engine E is transmitted to the automatic transmission AT via the motor generator MG and the starting clutch CL1, and the HEV mode uses the driving force of the engine E in addition to the motor generator MG. It becomes.

  In the HEV mode, the mode is further subdivided according to the magnitude and sign of driving force T (MG) generated by motor generator MG.

(Engine driving mode)
If the driving force T (MG) is zero, the engine traveling mode is established in which traveling is performed only by the driving force of the engine E.

(Motor assisted travel mode)
If the driving force T (MG) input from the motor generator MG to the automatic transmission AT is a positive value, the motor assist traveling mode is set in which the driving force of the motor generator MG and the engine E is used in combination.

(Running power generation mode)
The driving force T (MG) input from the motor generator MG to the automatic transmission AT is a negative value, that is, the motor generator MG does not generate torque but is rotated by the engine E or vehicle inertia and consumes external torque. In this case, the motor generator MG functions as a generator. Thereby, the battery 4 is charged.
If the vehicle is in an acceleration state or a constant speed traveling state, motor generator MG is rotated by engine E, and if the vehicle is in a deceleration state, motor generator MG is rotated by vehicle inertia to generate power.

[Control configuration]
The hybrid vehicle of the present application includes an engine controller 1, a motor controller 2, a power control unit 3, a battery 4, an AT controller 7, and an integrated controller 10.

  The engine speed information from the engine speed sensor 12 is input to the engine controller 1, and the engine operating point (Ne: engine speed, Te: engine torque) is controlled according to the target engine torque command from the integrated controller 10. To do. The engine speed Ne is output to the integrated controller 10 via the CAN communication line 11.

  The motor controller 2 is based on the rotor rotational position of the motor generator MG (detected by the resolver 13), the target motor generator torque command (calculated in the integrated controller 10), and the like, and the motor operating point of the motor generator MG (motor generator rotational speed N, motor A command for controlling the generator torque Tm) is output to the power control unit 3.

  Further, the motor controller 2 monitors the battery SOC indicating the state of charge of the battery 4. The battery SOC is used for control information of the motor generator MG and is supplied to the integrated controller 10 via the CAN communication line 11.

  The AT controller 7 controls the motor generator MG and the left and right sides based on sensor information from the accelerator opening sensor 16, the vehicle speed sensor 17 and the hydraulic sensor 18 provided in the automatic transmission AT, and the second clutch control command from the integrated controller 10. An engagement / release control command for the second clutch CL2 (a friction engagement element in the automatic transmission AT) interposed between the rear wheels RL and RR is output to the automatic transmission AT. Information on the accelerator opening APO and the vehicle speed VSP is supplied to the integrated controller 10 via the CAN communication line 11.

  The integrated controller 10 manages the energy consumption of the entire vehicle and bears a function for running the vehicle with the highest efficiency. A motor rotation speed Nm, a second clutch output rotation speed N2ouT, and a second clutch engagement torque TCL2 are input from the motor rotation speed sensor 21, the second clutch output rotation speed sensor 22, and the second clutch engagement torque sensor 23, respectively. Information obtained via the communication line 11 is input.

  Based on these input information, the integrated controller 10 outputs commands to the engine controller 1, the motor controller 2, the starting clutch controller 5, and the AT controller 7, and the engine E, the motor generator MG, the starting clutch CL1, and the automatic transmission AT, respectively. The second clutch CL2, which is the inner frictional engagement element, is controlled.

[Configuration of automatic transmission]
FIG. 2 is a skeleton diagram of the automatic transmission AT. The automatic transmission AT has front, mid, and rear planetary gears G1, G2, and G3 as rotating elements. Each planetary gear G1, G2, G3 has sun gears S1, S2, S3, carriers PC1, PC2, PC3, and ring gears R1, R2, R3 as rotating elements, respectively.

  Note that IN is the motor generator MG only, or an input shaft to which rotational driving torque is input from the engine E and the motor generator MG via a damper, and OUT is the left and right rear wheels RL, RR after passing through the automatic transmission AT. This is an output shaft that outputs a rotational drive torque to the shaft.

  As an engagement element that determines the shift speed of the fifth forward speed and the first reverse speed, the input clutch C1, the high & low reverse clutch C2, the direct clutch C3, the reverse brake B1, the front brake B2, the low coast brake B3, the forward A brake B4, a first one-way clutch F1, a third one-way clutch F2, and a forward one-way clutch F3 are provided.

  The input clutch C1 connects the front ring gear R1 to the input shaft IN when released, and connects the front ring gear R1 and the mid ring gear R2 to the input shaft IN when engaged. High & low reverse clutch C2 connects mid sun gear S2 and rear sun gear S3 when engaged. The direct clutch C3 connects the rear sun gear S3 and the rear carrier PC3 when engaged.

  The reverse brake B1 fixes the rear carrier PC3 to the transmission case TC by fastening. The front brake B2 fixes the front sun gear S1 to the transmission case TC by fastening. The low coast brake B3 fixes the mid sun gear S2 to the transmission case TC by fastening. Forward brake B4 fixes mid sun gear S2 to transmission case TC by fastening.

  The first one-way clutch F1 is free to rotate in the forward rotation direction (= the same rotation direction as the engine E) of the rear sun gear S3 with respect to the mid sun gear S2, and fixes reverse rotation. The third one-way clutch F2 frees the forward rotation direction of the front sun gear S1 and fixes the reverse rotation. The forward one-way clutch F3 frees the forward rotation direction of the mid sun gear S2 and fixes the reverse rotation.

  The output shaft OUT is directly connected to the mid carrier PC2. The front carrier PC1 and the rear ring gear R3 are directly connected by the first member M1. Mid ring gear R2 and rear carrier PC3 are directly connected by second member M2.

[Inertia phase area control block]
FIG. 3 is a control block diagram of the engine E and the motor generator MG executed in the integrated controller 10 in the inertia phase region of the automatic transmission AT.

  The torque control / rotation control determination unit 110 determines whether to perform torque control or rotation speed control based on a shift instruction from the driver, and outputs a determination result.

  The target rotation generation unit 120 calculates the target input shaft speed of the automatic transmission AT based on the determination result, and the rotation feedback control unit 130 calculates the output torque of the motor generator MG based on the target input shaft speed.

  An FF (feed forward) torque generation unit 140 calculates an engine torque based on the determination result, and a clutch hydraulic pressure control unit 150 during rotation control calculates an engagement torque of the second clutch CL2, which is a friction engagement element in the automatic transmission AT. .

  FIG. 4 is a map of engine required torque and FF (feed forward) output in the FF torque generator 140. This map is provided for each shift type (shift such as 2-3 upshift), and appropriately sets the FF output of the engine torque.

[Inertia phase torque control processing]
FIG. 5 is a flowchart showing a flow of torque control processing of the engine and the motor generator in the inertia phase.

  When the torque of the motor generator is smaller than the engine torque, the target rotational speed cannot be followed only by the torque of the motor generator.

  In this embodiment, even in such a case, the engine torque is reduced by feedforward control, a rough torque profile is created by the engine torque, and feedback control is performed by the motor generator torque. This provides a control device for a vehicle drive device that ensures follow-up to the target input shaft speed of the transmission AT. Hereinafter, each step will be described.

  In step S101, it is determined whether or not the phase has shifted to the inertia phase. If YES, the flow proceeds to step S102, and if NO, the control is terminated.

  In step S102, the motor generator MG is controlled to rotate, and the process proceeds to step S103.

  In step S103, the change rate of the target input shaft speed is set to the first ramp gradient α, and the process proceeds to step S104.

  In step S104, engine torque feed-forward control is performed, and the engine torque is reduced in accordance with the shift type, and the process proceeds to step S104.

In step S105, it is determined whether or not the actual value of the target input shaft rotational speed> the initial target rotational speed. If YES, step S105 is repeated, and if NO, the process proceeds to step S106.
This initial target rotational speed is a threshold value for switching the rate of change of the target input shaft rotational speed, and is set larger by a certain differential rotational speed (target switching determination differential rotational speed) than the final value of the target input shaft rotational speed. .
Therefore, when the actual value of the target input shaft rotational speed is less than the initial target rotational speed, the differential rotation between the actual value of the target input shaft rotational speed and the final value is equal to or less than the target switching determination differential rotation.

  In step S106, the target input shaft speed is set to a constant value, and the process proceeds to step S107.

In step S107, it is determined whether or not the actual input shaft rotational speed> the torque return determination threshold value. If YES, step S107 is repeated, and if NO, the process proceeds to step S108.
This torque return determination threshold value is a threshold value for determining whether or not to return the engine torque to the accelerator opening, and is larger by a certain differential rotation (torque return determination differential rotation) than the final value of the target input shaft rotation speed. Is set.
Therefore, when the actual value of the input shaft speed falls below the torque return determination threshold, the differential rotation between the actual value of the actual input shaft speed and the final value is equal to or less than the torque return determination threshold.
The torque return determination threshold is set to be larger than the initial target rotational speed in step S105.

  In step S108, the engine torque feed-forward control is ended, the engine torque is returned to the accelerator opening degree, and the process proceeds to step S109.

  In step S109, it is determined whether or not the elapsed time after the actual input shaft speed reaches the target input shaft speed is equal to or greater than the target switching determination time. If YES, the process proceeds to step S110. If NO, the process proceeds to step S110. S109 is repeated.

  In step S110, the change rate of the target input shaft speed is set to the second ramp gradient β, and the process proceeds to step S111.

  In step S111, it is determined whether or not the actual input shaft speed = the final value of the target input shaft speed. If YES, the control is terminated, and if NO, step S111 is repeated.

[Change in torque control during inertia phase over time]
FIG. 6 is a time chart of torque control of the engine and the motor generator in the inertia phase.

(Time t1)
At time t1, the phase shifts to the inertia phase, and the control of the motor generator MG shifts from the torque control to the rotation speed control. Thereafter, the engagement torque of the second clutch CL2 (the friction engagement element in the automatic transmission AT) is kept constant until time t7.
Further, the target input shaft rotational speed change rate becomes the first ramp gradient α, and the target input shaft rotational speed decreases at a constant rate.
Furthermore, feed forward of engine torque is started, the map is referred to according to the shift type (see FIG. 4), and the engine torque and motor generator torque are also reduced.

(Time t2)
At time t2, the actual value of the target input shaft rotational speed becomes equal to or less than the initial target rotational speed, and the target input shaft rotational speed becomes a constant value.
In order to make it easier for the driver to sense the shift response, it is better that the rotation rate change rate at the initial stage of the inertia phase is larger, and in order to reduce the shift shock, it is better that the rotation rate change rate at the completion of the inertia phase is smaller.
Therefore, by setting the change rate of the target input shaft rotational speed to decrease with time, both shift response and shock reduction are achieved.

(Time t3)
At time t3, the difference between the final value of the target input shaft speed and the actual input shaft speed becomes equal to or less than the torque return determination differential speed, and the engine torque feedforward control ends. As a result, the engine torque returns to the value corresponding to the accelerator opening.
By considering the engine torque response delay and setting the engine torque return timing earlier, it is possible to avoid undershooting the actual rotational speed of the transmission input shaft IN with respect to the final target rotational speed.

(Time t4)
At time t4, the actual input shaft speed reaches the target input shaft speed. At substantially the same time, the motor generator torque returns to the accelerator opening equivalent value.

(Time t5)
The time after the actual input shaft rotational speed reaches the target input shaft rotational speed at time t5 (the elapsed time from time t4) has passed the target switching determination time, and the target input shaft rotational speed decreases with the second ramp gradient β. To do. At time t2, the target input shaft speed is a constant value, and it can be determined that the slip state of the second clutch CL2 is sufficiently secured if a certain time has elapsed after the actual input shaft speed reaches the target input shaft speed. It is.
Therefore, by maintaining the target input rotation speed for a predetermined time, it is possible to avoid undershooting the actual input shaft rotation speed with respect to the target input shaft rotation speed. As a result, it is possible to prevent the relative rotation of the second clutch CL2 from becoming zero due to the undershoot and the slip control from being disabled.
The second ramp gradient β is set to be smaller than the first ramp gradient α between times t1 and t2. For this reason, the change rate of the target input shaft rotational speed is set so as to decrease with time, and it is possible to further improve the sensitivity of the shift response and reduce the shift shock.

(Time t6)
At time t6, the actual input shaft speed = the final value of the target input shaft speed.

(Time t7)
At time t7, the inertia phase ends, the second clutch CL2 is completely engaged, and the motor generator MG shifts from the rotational speed control to the torque control.

[Effect of Example 1]
(1) A vehicle drive including an engine E (first drive source), a motor generator MG (second drive source), and a stepped automatic transmission AT that achieves a predetermined shift stage by fastening a friction engagement element. In the control device of the apparatus, a target rotational speed generation unit 120 (target rotational speed calculation means) that calculates a target input shaft rotational speed of the automatic transmission AT at the time of shifting based on a driver's requested driving force, and an engine at the time of shifting A feedforward torque generator 140 that feedforward-controls the output torque of E based on the target input shaft rotational speed, and feedback control of the output torque of the motor generator MG at the time of gear shifting, thereby enabling the input shaft rotation of the automatic transmission AT. The feedback control unit 130 controls the number so as to follow the target input shaft rotation speed.

  Thus, even when the torque of the motor generator is smaller than the engine torque, a rough torque profile is created based on the engine torque, and feedback control is performed with the motor generator torque, so that the target input shaft rotation speed of the transmission AT is achieved. It is possible to provide a control device for a vehicle drive device that ensures the following ability.

  (2) When calculating the target input shaft speed, the target speed generator 120 sets the change rate of the target input shaft speed to decrease with time.

  In order to make it easier for the driver to sense the shift response, it is better that the rotation rate change rate at the initial stage of the inertia phase is larger, and in order to reduce the shift shock, it is better that the rotation rate change rate at the completion of the inertia phase is smaller. Therefore, by setting the change rate of the target input shaft rotational speed to decrease with time, it is possible to achieve both improvement in the sensitivity of the shift response and reduction of the shift shock.

  (3) The target rotational speed generation unit 120 changes the target input shaft rotational speed with the first ramp gradient α until the initial target rotational speed that is higher than the final target rotational speed at the completion of the shift, and the target input shaft rotational speed is initially set. When the target rotational speed is reached, the target input rotational speed is maintained for a predetermined time, and then the target input shaft rotational speed is changed to the final target rotational speed with the second ramp gradient β.

  By maintaining the target input speed for a predetermined time, the actual input shaft speed is prevented from undershooting the target input shaft speed, and the undershoot causes the relative rotation of the second clutch CL2 to become zero and slips. It is possible to prevent an uncontrollable state.

  (4) The target rotational speed generation unit 120 sets the initial target rotational speed according to the shift type. Thereby, the initial target rotational speed can be appropriately set according to the shift type.

  (5) The feedforward torque generation unit 140 ends the feedforward control when the input shaft rotational speed of the automatic transmission AT and the final target rotational speed become a predetermined rotational speed difference.

  By considering the engine torque response delay and setting the engine torque return timing early, it is possible to avoid undershooting the actual rotational speed of the transmission input shaft IN with respect to the final target rotational speed.

(6) The feedforward torque generation unit 140 sets the output torque of the engine E according to the shift type.
(7) The feedforward torque generation unit 140 sets the output torque of the engine E according to the change rate of the target input shaft rotational speed.
(8) The feedforward torque generator 140 sets the output torque of the engine E according to the driver's request for driving force.

  In (6), (7), and (8), the engine torque can be appropriately set according to each parameter.

(Other examples)
As mentioned above, although the control apparatus of the vehicle drive device of this invention has been demonstrated based on the Example, it is not restricted to this Example 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 of the present application, the target input shaft rotational speed of the transmission AT is reduced by the first ramp gradient, and after the actual input shaft rotational speed reaches the initial target rotational speed, the target rotational speed is maintained at a constant value, Although it is reduced by the ramp gradient, the target input shaft rotational speed may be reduced by the second ramp slope immediately after reaching the initial target rotational speed without maintaining a constant value.

  Further, in the first embodiment of the present invention, the control at the time of upshift is shown, but the followability to the target input shaft speed of the transmission AT can be ensured by performing the same control even at the downshift.

It is a system diagram of this application hybrid vehicle. It is a skeleton figure of automatic transmission AT. 2 is a control block diagram of an engine E and a motor generator MG executed in the integrated controller 10. FIG. 5 is a map of engine required torque and FF output in an FF torque generation unit 140. It is a flowchart which shows the flow of the torque control process of an engine and a motor generator in an inertia phase. It is a time chart of torque control of an engine and a motor generator in an inertia phase.

Explanation of symbols

E Engine CL1 Start clutch MG Motor generator AT Automatic transmission 1 Engine controller 2 Motor controller 3 Power control unit 4 Battery 6 Start clutch hydraulic unit 7 AT controller 10 Integrated controller

Claims (5)

A motor generator connected to the engine;
A stepped automatic transmission that is connected to the motor generator at an input shaft and achieves a predetermined shift stage by fastening a friction engagement element;
In a hybrid vehicle control device comprising:
Target rotational speed calculation means for calculating a target input shaft rotational speed of the stepped automatic transmission at the time of shifting based on a shift instruction;
Feedback control means for feedback-controlling the output torque of the motor generator at the time of shifting so that the rotational speed of the input shaft follows the target input shaft rotational speed;
During feedback control of the output torque of the motor generator at the time of shifting, the output torque corresponding to the accelerator opening of the engine is feedforward controlled so that the rotational speed of the input shaft follows the target input shaft rotational speed. Feedforward control means;
A control apparatus for a hybrid vehicle, comprising: In the hybrid vehicle control device according to claim 1,
The control apparatus for a hybrid vehicle , wherein the target rotational speed calculation means sets the change rate of the target input shaft rotational speed to decrease with time when calculating the target input shaft rotational speed. In the hybrid vehicle control device according to claim 2,
The target rotational speed calculation means includes
The target input shaft rotational speed is changed with a first ramp gradient up to an initial target rotational speed having a predetermined rotational speed difference with respect to a final target rotational speed at the completion of shifting of the target input shaft rotational speed,
When the target input shaft rotational speed reaches the initial target rotational speed, after maintaining the target input rotational speed for a predetermined time, the target input shaft rotational speed is changed to the final target rotational speed with a second ramp gradient. A control apparatus for a hybrid vehicle characterized by the above. The hybrid vehicle control device according to any one of claims 1 to 3,
The feedforward control means terminates the feedforward control when the input shaft rotational speed of the stepped automatic transmission and the final target rotational speed become a predetermined rotational speed difference.
A hybrid vehicle control device. In the hybrid vehicle control device according to any one of claims 1 to 4,
The feedforward control means sets the output torque of the engine according to a shift type.
A hybrid vehicle control device.

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