JP2019127068A - Hybrid vehicle - Google Patents

Abstract

To provide a hybrid vehicle capable of properly reducing or eliminating vibration which is caused by torsion of a torsional damper during backward movement of a vehicle.SOLUTION: A hybrid vehicle 1 determines a motor torque which should be output from a first motor generator 3 based on repulsion corresponding to torsion of a torsional damper 13 which is caused by driving of a second motor generator 4 when the hybrid vehicle moves backward by driving the second motor generator 4 with combustion of an internal combustion engine 2 being stopped, and controls the first motor generator 3 so as to output said motor torque.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a hybrid vehicle provided with an internal combustion engine and two motor generators.

  In the hybrid vehicle, vibration suppression control is performed to suppress the vibration generated in the power transmission system in the electric vehicle mode by the second motor generator. This vibration is generated by torque fluctuations of the drive shaft, and the torque fluctuations appear as fluctuations in the rotational speed of the second motor / generator. In conventional vibration suppression control, fluctuations in the number of revolutions of the second motor / generator are detected, a correction torque is calculated, and the command torque of the second motor / generator is feedback-corrected with the correction torque to suppress vibrations. There is.

  Patent Document 1 describes a hybrid vehicle that switches whether or not to execute such damping control depending on whether regeneration coordination replacement control is being performed to replace the regenerative torque of the second motor generator with the braking force of the hydraulic brake. It is done.

JP, 2014-50130, A

  In the case of a hybrid vehicle in which the internal combustion engine is connected to the power split mechanism via the torsional damper, in the electric vehicle mode, part of the torque of the second motor generator is transmitted to the torsional damper via the power split mechanism to The national damper is twisted. The twist may cause the rotating element of the power split mechanism to which the internal combustion engine is connected to vibrate. The conventional vibration damping control feeds back the rotational speed fluctuation of the second motor / generator, but the influence of torsional damper torsion is not taken into consideration. In addition, since the required torque of the second motor generator often increases when the vehicle starts to move backward, there is no room for the correction torque to be added to the required torque of the second motor generator. There is a possibility that the vibration as a factor cannot be suppressed or eliminated by correcting the command torque of the second motor / generator.

  Therefore, an object of the present invention is to provide a hybrid vehicle that can appropriately suppress or eliminate vibrations caused by torsion of a torsional damper when the vehicle starts moving backward.

  A hybrid vehicle according to an aspect of the present invention includes an internal combustion engine, a first motor / generator, an output unit for transmitting power to drive wheels, a torsional damper, and three rotational elements that are differentially rotatable with respect to each other. The internal combustion engine is connected to any one of the three rotating elements via the torsional damper, the first motor / generator is connected to the other one of the three rotating elements, and A power split mechanism in which the output unit is connected to the remaining one of the three rotating elements, a second motor / generator provided to transmit power to the output unit, and combustion of the internal combustion engine is stopped. And a control device capable of driving the second motor / generator in a state of being started to move backward, and the control device is configured to move the second motor / generator during the backward movement. The motor torque to be output from the first motor generator is determined based on the repulsive force according to the torsion of the torsional damper generated by the drive of the first motor generator, and the first motor generator is output so that the motor torque is output. Control.

FIG. 1 schematically shows an overall configuration of a hybrid vehicle according to an embodiment of the present invention. FIG. 2 is a collinear diagram of the power split mechanism of FIG. 1. The flowchart which showed an example of the control routine. The figure which showed the time change of the rotation speed of the 2nd motor generator at the time of control implementation. The figure which showed the time change of the rotation speed of the 2nd motor generator in the comparative example of control non-implementation.

  As shown in FIG. 1, a hybrid vehicle (hereinafter referred to as a vehicle) 1 includes an internal combustion engine 2 and two motor generators 3 and 4. The internal combustion engine 2 and the first motor / generator 3 are connected to a power split mechanism 5 configured as a planetary gear mechanism. The power of the internal combustion engine 2 is split by the power split mechanism 5, one of the split powers is used for power generation by the first motor generator 3, and the remaining power is output from the power split mechanism 5. The first motor / generator 3 often functions as a generator, but functions as an electric motor when used for motoring or the like when starting the internal combustion engine 2. A second motor generator 4 is provided in a power transmission path between the power split mechanism 5 and the drive wheel 7. The second motor generator 4 is used for assisting the power lacking in the internal combustion engine 2 alone, performing the electric vehicle mode, and performing regeneration control that generates electric power when the vehicle is decelerated.

  The internal combustion engine 2 is configured as, for example, an in-line four-cylinder spark ignition type internal combustion engine. The first and second motor generators 3 and 4 are configured as three-phase AC motor generators. A first inverter 11A is electrically connected to the first motor / generator 3, and a second inverter 11B is electrically connected to the second motor / generator 4. Each of the inverters 11A and 11B is electrically connected to an HV battery 12 provided as a power source of each of the motor generators 3 and 4.

  The power split mechanism 5 is configured as a single pinion type planetary gear mechanism. The power split mechanism 5 has a sun gear S of an external gear, a ring gear R of an internal gear coaxially disposed with the sun gear S, and a planet carrier C which holds a pinion P so as to be capable of rotating and revolving. . The pinion P meshes with each of the sun gear S and the ring gear R. The sun gear S, the ring gear R and the planet carrier C are differentially rotatable with each other.

  In this embodiment, the internal combustion engine 2 is connected to the planet carrier C of the power split mechanism 5 via the output shaft 2a, the torsional damper 13 and the input shaft 14, and the first motor / generator 3 is connected to the sun gear S. The drive shaft 17 is connected to the ring gear R via a gear train 15. Therefore, the carrier C, the sun gear S, and the ring gear R of the power split mechanism 5 correspond to an example of three rotating elements according to the above aspect, and the carrier C is an example of any one of the three rotating elements. The sun gear S corresponds to another rotating element of the three rotating elements, the ring gear R corresponds to an example of the remaining one rotating element, and the drive shaft 17 corresponds to an example of the output unit according to the above aspect.

  The gear train 15 includes an output gear 15a provided to rotate integrally with the ring gear R of the power split mechanism 5, and an output driven gear 15b provided on the drive shaft 17 and engaged with the output gear 15a. The power of the second motor generator 4 is transmitted to the drive shaft 17 via the motor drive shaft 18. The motor drive shaft 18 is provided with a motor gear 19 that meshes with the output driven gear 15b. The power of the drive shaft 17 is transmitted to the drive wheel 7 via the drive gear 20 and the differential mechanism 21.

  Control of each part of the vehicle 1 is controlled by an electronic control unit (ECU) 30 configured as a computer. The ECU 30 corresponds to an example of a control device according to the above aspect. The ECU 30 performs various controls on the internal combustion engine 2 and the motor generators 3 and 4 and the like. Various information on the vehicle 1 is input to the ECU 30. For example, to the ECU 30, an output signal of the first resolver 31 that outputs a signal according to the rotation angle of the first motor / generator 3 and a second resolver that outputs a signal according to the rotation angle of the second motor generator 4 An output signal of an accelerator opening degree sensor 33 which outputs a signal corresponding to a depression amount of an accelerator pedal 34, an output signal of a vehicle speed sensor 35 which outputs a signal corresponding to a vehicle speed of the vehicle 1, and an internal combustion engine An output signal of the crank angle sensor 36 which outputs a signal corresponding to a crank angle of 2 is input.

  The ECU 30 calculates the required power required by the driver with reference to the output signal of the accelerator opening sensor 33 and the output signal of the vehicle speed sensor 35, and sets various modes so that the system efficiency for the required power is optimized. The vehicle 1 is controlled while switching. For example, in the operation region where the thermal efficiency of the internal combustion engine 2 decreases, the electric vehicle mode in which the combustion of the internal combustion engine 2 is stopped and the second motor / generator 4 is driven is performed. When the torque is insufficient with the internal combustion engine 2 alone, a hybrid mode is implemented in which the second motor / generator 4 is used together with the internal combustion engine 2 as a driving source for travel.

  In the electric vehicle mode, the power of the second motor generator 4 is transmitted to the drive wheel 7 through the motor gear 19, the output driven gear 15b, the drive gear 20 and the differential mechanism 21, and the vehicle 1 can travel. On the other hand, part of the power of the second motor / generator 4 is transmitted to the power split mechanism 5 via the motor gear 19 and the gear train 15. Then, the power transmitted to the power split mechanism 5 is transmitted to the first motor generator 4 via the sun gear S, and is also transmitted to the output shaft 2 a of the internal combustion engine 2 via the carrier C, the input shaft 14 and the torsional damper 13. It is transmitted. As a result, the first motor / generator 4 rotates and the output shaft 2a of the internal combustion engine 2 that has stopped combustion rotates.

  When the vehicle 1 starts to move backward in the electric vehicle mode, vibrations may occur in the power transmission path for transmitting the power of the second motor / generator 4 because of the low rotation and high torque conditions. When the vibration occurs, the average torque actually transmitted to the drive wheels 7 with respect to the command torque required for the vehicle 1 decreases, and the rise of the vehicle speed deteriorates accordingly. Although this vibration occurs due to various factors, it has been found that the repulsive force according to the torsional damper 13 generated by the power of the second motor / generator 4 is one of the factors. As shown in the nomogram of FIG. 2, the repulsive force Tdmp generated by the torsional damper 13 twisting causes the torque fluctuation of the input shaft 14. Then, the repulsive force Tdmp is transmitted to the ring gear R of the power split mechanism 5 to generate a torque fluctuation of the drive shaft 17 to which the ring gear R and the second motor / generator 4 are connected. These torque fluctuations generate the vibration. In this embodiment, as shown in FIG. 2, the first motor generator 4 outputs the motor torque Tg for canceling the above-mentioned repulsive force Tdmp to suppress the vibration caused by the torsion of the torsional damper 13. Or eliminate.

  For example, the above control can be realized by the ECU 30 executing the control routine shown in FIG. The program of the control routine of FIG. 3 is held by the ECU 30, and is read out and executed when the electric vehicle mode is implemented.

  In step S1, the ECU 30 determines the success or failure of the control execution condition. In the present embodiment, as the control execution condition, for example, it is set that the vehicle 1 is moving backward and the high torque state in which the required torque to the second motor generator 4 exceeds a predetermined value. It should be noted that the time of reverse start includes a transitional period from when the vehicle 1 starts moving to the vehicle speed required by the driver, for example, a time of 4 to 5 seconds from when the vehicle 1 starts moving is assumed as a time of reverse start It is done. The high torque state includes the maximum torque state corresponding to the output limit of the second motor generator 4. Whether the predetermined value for determining the high torque state has enough margin to suppress the vibration caused by the torsion of the torsional damper 13 by the conventional damping control that corrects the motor torque of the second motor generator 4 or not It is decided on the basis of Therefore, when there is a margin, the vibration can be suppressed by the conventional damping control by the second motor generator 4, for example.

  The ECU 30 refers to a signal from the vehicle speed sensor 35 and refers to a signal from a shift position sensor (not shown) to determine whether or not the vehicle 1 is moving backward. Further, the ECU 30 calculates the required torque for the second motor / generator 4 based on the signal from the accelerator opening sensor 33, and determines whether or not the required torque is in a high torque state exceeding a predetermined value. If the control execution condition is satisfied, the process proceeds to step S2, and if not, the subsequent process is skipped and the current routine is terminated.

  In step S <b> 2, the ECU 30 estimates the angular velocity of the input shaft 14 based on the rotational speed of the first motor / generator 3 and the rotational speed of the second motor / generator 4. The rotational speed of the first motor / generator 3 is acquired based on the signal of the first resolver 31, and the rotational speed of the second motor / generator 4 is acquired based on the signal of the second resolver 32. And ECU30 calculates the angular velocity Nip of the input shaft 14 based on the following formula | equation 1, for example.

Nip = ρ / (1 + ρ) · Ng + 1 (1 + ρ) · i · Nm ...... 1
Where Ng: rotational speed of the first motor generator 3, Nm: rotational speed of the second motor generator 4, ρ: number of teeth of sun gear S / number of teeth of ring gear R, i: second motor generator 4 To the output gear 15a.

  In step S3, the ECU 30 estimates the torsional amount of the torsional damper 13 based on the angular velocity of the input shaft 14 and the angular velocity of the output shaft 2a of the internal combustion engine 2. The angular velocity of the output shaft 2 a is obtained based on the signal of the crank angle sensor 36. Then, the ECU 30 calculates the amount of twist Wdmp of the torsional damper 13 based on, for example, the following equation 2.

Wdmp = (Nip−Ncrnk) / 60 / (2π) · Ts 2
Here, Ncrnk: angular velocity of the output shaft 2a, Ts: control cycle.

  In step S4, the ECU 30 estimates the repulsive force of the torsional damper 13 based on the amount of twist. The ECU 30 calculates the repulsive force Tdmp of the torsional damper 13 based on the following formula 3, for example.

Tdmp = Wdmp · Kdmp ...... 3
Here, Kdmp is a coefficient of elasticity of the torsional damper 13.

  In step S5, the ECU 30 estimates the inertial force of the first motor / generator 3 based on the amount of change in the rotational speed of the first motor / generator 3 per unit time. The ECU 30 calculates, for example, the inertia force Tginer of the first motor generator 3 based on the following equation 4.

Tginer = (ΔNg / Ts) · Ig 4
Here, Ig is an inertia coefficient of the first motor / generator 3, and ΔNg is a change amount of the rotation speed of the first motor / generator 3 per unit time.

  In step S6, the ECU 30 determines the motor torque to be output by the first motor generator 3 based on the repulsive force of the torsional damper 13 acquired in step S4 and the inertial force of the first motor generator 3 acquired in step S5. Do. The ECU 30 calculates the motor torque Tg based on, for example, the following equation 5.

      Tg = ρ / (1 + ρ) · Tdmp−Tginer ...... 5

  In step S7, the ECU 30 controls the first motor generator 3 so that the motor torque determined in step S6 is output. Then, the process returns to step S1.

(Effect of this embodiment)
According to the present embodiment, by causing the first motor generator 3 to output the motor torque Tg determined in step S6 of FIG. 3, the repulsive force Tdmp of the torsional damper 13 is canceled as shown in FIG. Thereby, the vibration caused by the torsion of the torsional damper 13 can be suppressed or eliminated. As apparent from FIGS. 4A and 4B, the rotational speed fluctuation of the second motor / generator 4 in the comparative example was remarkable, but the rotational speed of the second motor / generator 4 was achieved by carrying out the control of this embodiment. It can be understood that the fluctuation is suppressed and the vibration caused by the torsion of the torsional damper 13 is suppressed by the control of this embodiment. In FIGS. 4A and 4B, since the vehicle 1 is moved backward on a slope where the front of the vehicle is inclined downward, the vehicle 1 is lowered to the front side of the vehicle at the start. Therefore, the rotational speed of the second motor generator 4 has a positive value in the range of about 0 to 1.5 seconds at the beginning of the reverse start.

  Further, the control of this embodiment is performed in the high torque state, which is a requirement for establishing the control execution condition, in step S1 of FIG. 3, and when the required torque for the second motor / generator 4 is smaller than the high torque state. Damping control by the first motor generator 3 is not performed. For this reason, when vibration can be suppressed by vibration suppression control by the second motor / generator 4, for example, vibration can be suppressed by executing conventional vibration suppression control. Therefore, the power consumption of the first motor / generator 4 can be reduced as compared with the case where the vibration control by the first motor / generator 3 is performed regardless of the magnitude of the required torque for the second motor / generator 4.

(Modification)
Although the said form determines the motor torque which should be output from the 1st motor generator 3 based on said Formulas 1-5, it is an example. For example, the motor to be output to the first motor generator 3 corresponding to the operating condition (respective rotational speeds of the first motor generator 3 and the second motor generator 4) at the time of backward start of the vehicle 1 by actual machine test or simulation. A database such as a map specifying torques is created and stored in the ECU 30, and the motor torque corresponding to the current driving state of the vehicle 1 can be changed to a mode in which the motor torque is determined by searching the database.

  In the above embodiment, the control execution condition includes a high torque state in which the required torque for the second motor / generator 3 is higher than a predetermined value. For example, the first motor may be used when the vehicle starts moving backward regardless of the magnitude of the required torque. -It can change into the form which implements damping control by the generator 3. FIG.

  The form or the modification is an example in which the motor torque to be output from the first motor / generator 3 is determined so that the repulsive force according to the torsional damper 13 is twisted. For example, although the repulsive force according to the torsion of the torsional damper 13 is not completely canceled out, it should be output from the first motor generator 3 based on the repulsive force so that at least the repulsive force is reduced. It can also be changed to a mode for determining the motor torque. Thereby, the vibration caused by the torsion of the torsional damper 13 can be suppressed. The vibrations may be suppressed or eliminated by canceling or reducing the repulsive force by the motor torque of the first motor / generator according to the above-described form or a modification thereof.

  Aspects of the present invention derived from each of the above-described embodiments and modifications will be described below.

  A hybrid vehicle according to an aspect of the present invention includes an internal combustion engine (2), a first motor / generator (3), an output unit (17) for transmitting power to drive wheels (7), and a torsional damper. (13) and three rotating elements (S, C, R) that can rotate differentially with each other, and the internal combustion engine is connected to any one of the three rotating elements (C) via the torsional damper. Power that is connected, the first motor / generator is connected to the other one of the three rotating elements (S), and the output unit is connected to the other one of the three rotating elements (R) A split mechanism (5), a second motor / generator (4) provided to transmit power to the output unit, and driving the second motor / generator in a state where combustion of the internal combustion engine is stopped. Control device that can start backward (30), wherein the control device controls the first motor generator based on a repulsive force according to the torsion of the torsion damper generated by the drive of the second motor generator at the time of reverse start. The motor torque to be output is determined, and the first motor generator is controlled to output the motor torque. In addition, although the referential mark which concerns on the said form was attached in parentheses, it is not the meaning limited to said each form.

  According to the hybrid vehicle of this aspect, the motor torque to be output from the first motor generator is determined based on the repulsive force corresponding to the torsion of the torsional damper at the time of reverse start, and the motor torque is determined by the first motor generator. Output from Since the motor torque to be output from the first motor generator is determined based on the repulsive force according to the torsion of the torsional damper, suppressing or eliminating the vibration caused by the torsion of the torsional damper Can.

DESCRIPTION OF SYMBOLS 1 Hybrid vehicle 2 Internal combustion engine 3 1st motor generator 4 Second motor generator 5 Power split mechanism 13 Torsional damper 17 Drive shaft (output part)
30 ECU (control device)
C Planet Carrier R Ring Gear S Sun Gear

Claims (1)

An internal combustion engine;
A first motor generator,
An output for transmitting power to the drive wheels;
Torsion damper,
The internal combustion engine is connected to any one of the three rotating elements via the torsional damper, and the other one of the three rotating elements is connected to the one of the three rotating elements. A power split mechanism in which a first motor generator is connected and the output is connected to one of the remaining three rotating elements;
A second motor generator provided to be able to transmit power to the output unit;
And a control device capable of driving the second motor / generator to make a reverse start when the combustion of the internal combustion engine is stopped.
The control device determines a motor torque to be output from the first motor / generator based on a repulsive force according to torsion of the torsional damper generated by driving the second motor / generator at the time of the backward start. And a hybrid vehicle that controls the first motor generator so that the motor torque is output.

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