JP3892611B2 - Control device for hybrid vehicle - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a hybrid vehicle control device that uses an engine and two motors in combination, and more particularly to a hybrid vehicle control device that can switch between a series travel mode and a parallel travel mode in accordance with travel conditions.
[0002]
[Prior art]
In recent years, in vehicles such as automobiles, a hybrid vehicle using both an engine and a motor has been developed from the viewpoint of low pollution and resource saving. This hybrid vehicle is equipped with two motors for power generation and power source. As a result, many technologies for improving the recovery efficiency of motive energy and ensuring the running performance are employed.
[0003]
In such a hybrid vehicle, a motor for power generation is driven by the mechanical output of the engine, and the motor for traveling is driven by the power generation output and the discharge output of the battery, and the vehicle is driven mainly by the mechanical output of the engine. It is known that the vehicle travels and switches between a parallel traveling mode in which a difference in mechanical output of the engine with respect to a required output is compensated by a motor according to an operating condition.
[0004]
For example, JP-A-8-098322 discloses an engine, a generator driven by the mechanical output of the engine, a battery charged by the generator output of the generator, and a motor driven by the discharge output of the battery. A series-parallel composite electric vehicle having connection opening / closing means such as a clutch for opening / closing mechanical connection between a generator and a motor is disclosed.
[0005]
In the above series-parallel composite electric vehicle, parallel running is performed by clutch engagement, and series traveling is performed by clutch release, and when the clutch is engaged, the rotational speed of the generator and the rotational speed of the motor must be matched. Thus, the clutch fastening shock is prevented.
[0006]
[Problems to be solved by the invention]
However, when switching from series running to parallel running, simply changing the generator speed and motor speed to close the clutch will cause torque fluctuations due to the difference in output torque between the engine side and the motor side. In addition, when switching from parallel travel to series travel, simply changing the clutch may cause rotational fluctuations or torque fluctuations.
[0007]
The present invention has been made in view of the above circumstances, and is a hybrid vehicle capable of preventing rotational fluctuation and torque fluctuation at the time of switching between series running and parallel running and realizing smooth running without deteriorating driving feeling. It aims to provide a control device.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, a first motor connected between an output shaft of an engine and a sun gear of a single pinion planetary gear, and a second motor connected to a ring gear of the planetary gear. A lock-up clutch that engages and releases the sun gear and the carrier of the planetary gear, and the planetary gear and the drive wheel that is connected to the planetary gear carrier and can be switched between a plurality of stages or continuously. When the hybrid vehicle is equipped with a power conversion mechanism that performs gear shifting and torque amplification, the lock-up clutch is released. And combining a part of the driving force of the engine and the driving force of the second motor. The series drive mode to drive and the above lock-up clutch Using at least the driving force of the engine A hybrid vehicle control device for switching to a parallel driving mode for driving, wherein the driving torque of the engine is gradually increased at the time of transition from the series driving mode to the parallel driving mode to drive the driving torque in the parallel driving mode. To Furthermore, after controlling the rotational speed command of the first motor, There is provided a means for causing the rotational speed of the first motor to substantially coincide with the input shaft rotational speed of the power conversion mechanism and fastening the lockup clutch.
[0009]
According to a second aspect of the present invention, in the first aspect of the present invention, the engine driving torque is gradually reduced and the engine driving torque is reduced when the parallel driving mode is shifted to the series driving mode. The rotational speed of the second motor when the driving torque of the second motor is gradually increased by the decrease and the driving torque of the engine becomes substantially zero. After controlling the rotational speed command of the first motor, A means for releasing the lock-up clutch is provided.
[0010]
That is, in the first aspect of the invention, the first motor connected between the engine output shaft and the sun gear of the single pinion planetary gear, the second motor connected to the ring gear of the planetary gear, the sun gear of the planetary gear and the carrier And a power conversion mechanism that is connected to a planetary gear carrier and performs gear shifting and torque amplification between the planetary gear and the drive wheel according to a gear ratio that can be switched between a plurality of stages or continuously. Release the lock-up clutch in a hybrid vehicle equipped with , Combining a part of the driving force of the engine and the driving force of the second motor From the series running mode to run , Engage the lock-up clutch Using at least the driving force of the engine When shifting to the parallel driving mode, the engine driving torque is gradually increased to shift to the driving torque in the parallel driving mode. Furthermore, after controlling the rotational speed command of the first motor, The rotational speed of the first motor is substantially matched with the rotational speed of the input shaft of the power conversion mechanism, and the lockup clutch is fastened.
[0011]
In invention of Claim 2, , Pa When shifting from the Larrel travel mode to the series travel mode, the engine drive torque is gradually decreased and the second motor drive torque is gradually increased by the decrease of the engine drive torque to drive the engine. Number of rotations of the second motor when the torque becomes substantially zero After controlling the rotational speed command of the first motor, Release the lock-up clutch.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. 1 to 8 relate to an embodiment of the present invention, FIG. 1 is a flowchart showing a switching determination routine between the series running mode and the parallel running mode, FIG. 2 is a flowchart showing a control routine for the series running mode, and FIG. FIG. 4 is a flowchart showing a control routine for switching from the series running mode to the parallel running mode, FIG. 4 is a flowchart showing a control routine for the parallel running mode, and FIG. 5 is a flowchart showing a control routine for shifting from the parallel running mode to the series running mode. 6 is an explanatory diagram of a driver required torque map, FIG. 7 is an explanatory diagram showing the relationship between the vehicle speed for clutch engagement / disengagement determination and the driver required torque, and FIG. 8 is an explanatory diagram showing the configuration of the drive control system.
[0013]
As shown in FIG. 8, the hybrid vehicle according to the present invention includes an engine 1, a motor A (first motor) that is responsible for starting the engine 1 and generating and assisting power generation, and an output shaft 1 a of the engine 1 via the motor A. Connected planetary gear unit 3, the function of planetary gear unit 3, motor B (second motor) that serves as a driving force source for start and reverse, and collects deceleration energy, and gear shifting and torque amplification And a drive system having a basic configuration of a power conversion mechanism 4 that performs a power conversion function during traveling.
[0014]
Specifically, the planetary gear unit 3 is a single pinion type planetary gear having a sun gear 3a, a carrier 3b that rotatably supports a pinion that meshes with the sun gear 3a, and a ring gear 3c that meshes with the pinion. The sun gear 3a and the carrier 3b A lock-up clutch 2 for fastening and releasing is attached.
[0015]
As the power conversion mechanism 4, a transmission using a combination of gear trains, a transmission using a fluid torque converter, or the like can be used. However, a primary pulley 4b and an output shaft 4c that are supported by the input shaft 4a. It is desirable to employ a belt type continuously variable transmission (CVT) in which a drive belt 4e is wound between the secondary pulley 4d and the secondary pulley 4d. In this embodiment, the power conversion mechanism 4 is hereinafter referred to as a CVT4. Will be described.
[0016]
In other words, in the hybrid vehicle drive system of this embodiment, the planetary gear unit 3 having the lockup clutch 2 interposed between the sun gear 3a and the carrier 3b is disposed between the output shaft 1a of the engine 1 and the input shaft 4a of the CVT 4. The sun gear 3a of the planetary gear unit 3 is coupled to the output shaft 1a of the engine 1 via one motor A, and the carrier 3b is coupled to the input shaft 4a of the CVT 4 as an output stage of power to the ring gear 3c. The other motor B is connected. A differential mechanism 6 is connected to the output shaft 4 c of the CVT 4 via a reduction gear train 5, and a front wheel or rear wheel drive wheel 8 is connected to the differential mechanism 6 via a drive shaft 7.
[0017]
In this case, as described above, the engine 1 and the motor A are coupled to the sun gear 3a of the planetary gear unit 3, and the motor B is coupled to the ring gear 3c to obtain an output from the carrier 3b. Therefore, the two motors A and B can be used for both power generation and driving force supply, and use a relatively small output motor. be able to.
[0018]
Further, the sun gear 3a of the planetary gear unit 3 and the carrier 3b are coupled by the lock-up clutch 2 according to the driving conditions, so that two motors A and B are disposed between the engine 1 and the CVT 4 directly connected to the engine. A drive shaft can be formed, and the drive force can be efficiently transmitted to the CVT 4 or the braking force from the drive wheel 8 side can be used.
[0019]
Regarding the torque transmission of the engine 1 and the motors A and B via the planetary gear unit 3 when the lockup clutch 2 is engaged / released and the flow of electricity by power generation, Japanese Patent Application No. 10- No. 4080.
[0020]
The above drive system is controlled by a control system (hybrid control system) that controls the traveling of a hybrid vehicle in which seven electronic control units (ECUs) are coupled by a multiplex communication system. And a functional circuit controlled by a microcomputer.
[0021]
Specifically, centering on a hybrid ECU (HEV_ECU) 20 that controls the entire system, a motor A controller 21 that controls the drive of the motor A, a motor B controller 22 that controls the drive of the motor B, an engine ECU that controls the engine 1 ( E / G_ECU) 23, a transmission ECU (T / M_ECU) 24 that controls the lockup clutch 2 and CVT 4, and a battery management unit (BAT_MU) 25 that manages the power of the battery 10 are connected to the HEV_ECU 20 via the first multiplex communication line 30. A brake ECU (BRK_ECU) 26 that is coupled and performs brake control is coupled to the HEV_ECU 20 via a second multiplex communication line 31.
[0022]
The HEV_ECU 20 controls the entire hybrid control system. The HEV_ECU 20 is a sensor / switch for detecting the driving operation status of the driver, for example, an accelerator pedal sensor (APS) 11 for detecting a depression amount of an accelerator pedal (not shown), not shown. A brake switch 12 that is turned on when the brake pedal is depressed, a shift range switch 14 for detecting the operation range position of the transmission select mechanism unit 13, and the like are connected.
[0023]
Then, the HEV_ECU 20 calculates the necessary vehicle drive torque based on the signals from the sensors and switches and the data transmitted from the ECUs to determine the torque distribution of the drive system. Send.
[0024]
The HEV_ECU 20 is connected to a display 27 including various meters for displaying the vehicle operating state such as the vehicle speed, the engine speed, and the battery charging state, and a warning lamp for warning the driver when an abnormality occurs. ing. The indicator 27 is also connected to the T / M_ECU 24, and when an abnormality occurs in the HEV_ECU 20, the T / M_ECU 24 performs abnormality control in place of the HEV_ECU 20 and displays an abnormality on the indicator 27.
[0025]
On the other hand, the motor A controller 21 includes an inverter for driving the motor A. Basically, the constant rotation speed of the motor A is determined by a servo ON / OFF command or a rotation speed command transmitted from the HEV_ECU 20 by multiplex communication. Take control. Further, the motor A controller 21 sends the HEV_ECU 20 the torque, rotation speed, current value, and the like of the motor A with feedback, and further transmits data such as a torque limit request and a voltage value.
[0026]
The motor B controller 22 includes an inverter for driving the motor B. Basically, a servo ON / OFF (including forward rotation and reverse rotation) command and a torque command (power running) transmitted from the HEV_ECU 20 through multiplex communication. , Regeneration), constant torque control of the motor B is performed. Further, the motor B controller 22 feeds back and transmits the torque, rotation speed, current value, and the like of the motor B to the HEV_ECU 20, and further transmits data such as a voltage value.
[0027]
The E / G_ECU 23 basically controls the torque of the engine 1, and includes control commands such as positive and negative torque commands, fuel cut commands, air conditioner ON / OFF permission commands, etc. transmitted from the HEV_ECU 20 by multiplex communication, Not shown based on torque feedback data, vehicle speed, shift range position by shift range switch 14, accelerator fully open data or accelerator fully closed data by APS11 signal, brake switch 12 ON / OFF state, brake operating state including ABS, etc. It controls fuel injection amount from the injector, throttle opening by ETC (electric throttle valve), power correction learning of auxiliary equipment such as A / C (air conditioner), fuel cut and the like.
[0028]
In addition, the E / G_ECU 23 instructs the HEV_ECU 20 to execute the control torque value of the engine 1, the fuel cut, the full opening increase correction for the fuel injection amount, the ON / OFF state of the air conditioner, and the throttle valve fully closed data by an idle switch (not shown). Are fed back to the HEV_ECU 20 and transmitted, and a warm-up request for the engine 1 is transmitted.
[0029]
The T / M_ECU 24 controls the CVT 4 target primary pulley rotational speed, CVT input torque instruction, control command such as a lock-up request transmitted from the HEV_ECU 20 by multiplex communication, and the E / G rotational speed, accelerator opening, shift range switch 14. The lock-up clutch 2 is engaged and disengaged based on information such as the shift range position by the brake switch 12, the ON / OFF state of the brake switch 12, the air conditioner switching permission, the brake operation state including ABS, and the throttle valve fully closed data of the engine 1 by the idle switch The release is controlled and the gear ratio of the CVT 4 is controlled.
[0030]
Further, the T / M_ECU 24 feeds back to the HEV_ECU 20 data such as the vehicle speed, the input limiting torque, the primary pulley rotational speed and the secondary pulley rotational speed of the CVT 4, the lockup completion, and the shift state corresponding to the shift range switch 14. Along with the transmission, an E / G rotation speed increase request, a low temperature start request, etc. for increasing the oil amount of the CVT 4 are transmitted.
[0031]
The BAT_MU 25 is a so-called power management unit, and performs various controls for managing the battery 10, that is, charge / discharge control of the battery 10, fan control, external charge control, etc., and the remaining capacity, voltage, and current limit of the battery 10 Data such as values and data indicating that external charging is in progress are transmitted to the HEV_ECU 20 by multiplex communication. When external charging is performed, the contactor 9 is switched to disconnect the battery 10 from the motor A controller 21 and the motor B controller 22.
[0032]
The BRK_ECU 26 calculates a necessary braking force based on information such as a regenerative possible amount and regenerative torque feedback transmitted from the HEV_ECU 20 through multiplex communication, and controls the hydraulic pressure of the brake system. The BRK_ECU 20 Command (torque command), vehicle speed, hydraulic pressure, brake operation state including ABS, etc. are fed back and transmitted.
[0033]
When viewed from the transmission input shaft (4a), the traveling mode of the hybrid vehicle controlled by the above hybrid control system can be roughly divided into the following three basic modes. The state transition is repeated.
[0034]
(1) Series (series & parallel) travel modes
When the required driving force or the vehicle speed is small, the lock-up clutch 2 is released, the motor 1 is driven as a generator by the engine 1, and the motor B travels mainly. At this time, part of the driving force of the engine 1 is input to the sun gear 3a of the planetary gear unit 3, and is combined with the driving force of the motor B of the ring gear 3c and output from the carrier 3b.
[0035]
(2) Parallel travel mode
When the required driving force or vehicle speed is large, the lockup clutch 2 is engaged to couple the sun gear 3a and the carrier 3b of the planetary gear unit 3, and the driving force of the motor B is added to the driving force of the engine 1 from the ring gear 3c. It outputs from 3b, and it drive | works using the torque of both the engine 1 alone or the engine 1 and the motor B.
[0036]
(3) Braking force regeneration mode
During deceleration, the braking force is regenerated by the motor B in cooperation with the brake control. That is, the brake torque corresponding to the depression amount of the brake pedal is shared by the regenerative torque by the motor B and the braking torque by the brake mechanism to perform regenerative braking.
[0037]
Hereinafter, the switching determination process of each travel mode by the HEV_ECU 20 and the transition control between the travels will be described with reference to the flowcharts of FIGS.
[0038]
FIG. 1 is a routine for determining whether to switch between the series travel mode and the parallel travel mode. First, in step S51, the current vehicle speed V, the primary pulley rotation speed Np of the CVT 4, and the engagement / release state of the lockup clutch 2 are as follows. When input from the T / M_ECU 24 by multiplex communication, in step S52, the accelerator opening Acc is calculated based on the signal from the APS 11, and the shift range position is calculated based on the signal from the shift range switch 14.
[0039]
In the following step S53, based on the accelerator opening degree Acc and the primary pulley rotation speed Np, the following is shown depending on whether the shift range position belongs to the travel (forward travel) range, neutral or parking range, or reverse range. In addition, for each range, a driver request torque Tdrv that is an input torque of the CVT 4 is calculated. This driver required torque Tdrv is the output torque of the power stage calculated in consideration of the power distribution by the planetary gear 3, the remaining battery capacity, etc., and a complicated calculation that takes into account the effects of torque conversion loss etc. in the CVT 4 The required drive torque of the vehicle can be represented by a simple process without performing it.
[0040]
(A) Travel (forward travel) range
The driver request torque Tdrv is calculated by taking the accelerator opening Acc reflecting the driver's operation amount and the rotation speed of the carrier 3b of the planetary gear 3 reflecting the output state of the engine 1 and the motors A and B, that is, the primary pulley rotation speed Np of the CVT4. The function fa (Acc, Np) as a parameter can be indicated. Specifically, a value obtained by simulation or experiment in advance using the accelerator opening Acc and the primary pulley rotation speed Np as parameters is stored in a map. The driver request torque Tdrv is calculated with reference to this map.
[0041]
(B) Neutral or parking range
In the neutral or parking range, it is considered that there is no active drive torque request, and the driver request torque is set to Tdrv = 0.
[0042]
(C) Reverse range
In the reverse range, the driver request torque Tdrv is basically the same as that in the travel (forward travel) range, but since the traveling direction is reverse, the driver request torque Tdrv is given a minus sign − Let it be fa (Acc, Np).
[0043]
FIG. 6 shows a map fa of the driver request torque Tdrv using the accelerator opening Acc and the primary pulley rotation speed Np as parameters, and as the accelerator opening Acc increases, the value of the driver request torque Tdrv increases. At the opening, the lower the primary pulley rotation speed Np, the greater the driver request torque Tdrv.
[0044]
After calculating the driver request torque Tdrv as described above, the process proceeds to step S54, and a clutch release determination vehicle speed V1of for determining the release of the lockup clutch 2 is calculated by comparison with the current vehicle speed V. The vehicle speed V1of takes into account the effect of CVT4 and its gear ratio, and when shifting from the parallel travel mode to the series travel mode, the fuel efficiency of the engine 1 and the efficiency of the motors A and B are optimal in accordance with the driver required torque Tdrv. Is determined as a vehicle speed for determination by a function f1of (Tdrv) using the driver required torque Tdrv as a parameter. Specifically, values obtained by simulation or experiment in advance are stored in a table and calculated with reference to this table.
[0045]
Next, in step S55, a clutch engagement determination vehicle speed V1on for determining engagement of the lockup clutch 2 is calculated by comparison with the current vehicle speed V. Similarly, the clutch engagement determination vehicle speed V1on takes into account the effects of the CVT4 and its gear ratio, and the fuel efficiency efficiency of the engine 1 corresponding to the driver required torque Tdrv when shifting from the series travel mode to the parallel travel mode. The region in which the efficiency of the motors A and B is optimal is determined, and is determined as the vehicle speed for determination by the function f1on (Tdrv) using the driver required torque Tdrv as a parameter. Specifically, values obtained by simulation or experiment in advance are stored in a table and calculated with reference to this table.
[0046]
As shown in FIG. 7, the clutch disengagement determination vehicle speed V1of and the clutch engagement determination vehicle speed V1on are set such that the determination vehicle speed decreases as the driver request torque Tdrv increases, and the vehicle travels in the series travel mode. During this time, it is possible to shift to the parallel driving mode at a vehicle speed that optimizes the fuel efficiency of the vehicle while reflecting the driver's intention to accelerate, while reflecting the driver's intention to decelerate while driving in the parallel driving mode. However, it is possible to shift to the series travel mode at a vehicle speed at which the fuel efficiency of the vehicle is optimal. Further, at the same driver request torque Tdrv, the hysteresis is set to have a hysteresis of V1of <V1on, thereby preventing hunting during clutch release / engagement.
[0047]
Next, the process proceeds to step S56, where the current vehicle speed V is compared with the clutch engagement determination vehicle speed V1on. If V ≧ V1on, the process proceeds to step S57 to indicate that the condition for switching from the series travel mode to the parallel travel mode is satisfied. Therefore, the parallel travel condition establishment flag FLAG1 is set (FLAG1 ← 1), and the parallel → series transition control completion flag FLAG3 is cleared to indicate that the transition control from the parallel travel mode to the series travel mode is not performed. (FLAG3 ← 0), the process proceeds to step S60.
[0048]
If V <V1on in step S56, the process branches to step S58 to compare the current vehicle speed V with the clutch release determination vehicle speed V1of. If V> V1of, that is, if the current vehicle speed V is between the clutch engagement determination vehicle speed V1on and the clutch release determination vehicle speed V1of (V1on>V> V1of), step S60 is performed to maintain the current travel mode. When V ≦ V1of, the parallel travel condition satisfaction flag FLAG1 is cleared (FLAG1 ← 0) to indicate that the condition for switching from the parallel travel mode to the series travel mode is satisfied in step S59. In order to indicate that the transition control to the parallel travel mode is not yet performed, the series → parallel transition control completion flag FLAG2 is cleared (FLAG2 ← 0), and the process proceeds to step S60.
[0049]
Next, in step S60, the value of the parallel travel condition establishment flag FLAG1 is referred to. When FLAG1 = 1 and the condition for switching from the series travel mode to the parallel travel mode is satisfied, in step S61, the series → Referring to the value of the parallel transition control completion flag FLAG2, it is checked whether or not the transition control from the series travel mode to the parallel travel mode has been completed.
[0050]
As a result, in step S61, if FLAG2 = 0 and the transition control from the series travel mode to the parallel travel mode is not completed, the transition from the series travel mode to the parallel travel mode by the transition control routine of FIG. 3 is performed in step S62. When the control is executed and FLAG2 = 1 and the transition control from the series travel mode to the parallel travel mode is already completed, the parallel travel control by the control routine of FIG. 4 is performed in step S63.
[0051]
On the other hand, if the result of referring to the parallel travel condition establishment flag FLAG1 in step S60 is FLAG1 = 0 and the switching condition from the parallel travel mode to the series travel mode is satisfied, the process proceeds from step S60 to step S64, where → Refer to the value of series transition control completion flag FLAG3.
[0052]
If FLAG3 = 0 and the transition control from the parallel travel mode to the series travel mode is not completed, the transition control from the parallel travel mode to the series travel mode by the transition control routine of FIG. If FLAG3 = 1 and the transition control from the parallel travel mode to the series travel mode has already been completed, the series travel control by the control routine of FIG. 2 is performed in step S66.
[0053]
Next, with regard to the control of each travel mode determined by the above travel mode switching determination and the transition control between each travel mode, from the series travel mode, the transition control from the series travel to the parallel travel mode, the parallel travel control, and the parallel travel This will be described in the order of the shift control to the series running.
[0054]
In the series travel mode, in the control routine shown in FIG. 2, first, in step S101, when a rotational speed command for operating the motor A at a constant speed at a predetermined rotational speed is given to the motor A controller 21 by multiplex communication, in step S102, Driver requested torque Tdrv is calculated based on accelerator opening Acc and primary pulley rotation speed Np of CVT4.
[0055]
Next, the process proceeds to step S103, where the driver requested torque Tdrv is calculated by using the planetary gear ratio of the planetary gear unit 3 (planetary ratio: constant K) and the torque Tr on the ring gear side calculated by the following equations (1) and (2) and the sun gear. To the torque Ts on the side.
Tr = Tdrv × (1-K) / K (1)
Ts = Tdrv × K (2)
[0056]
In the subsequent step S104, the required power Wb of the motor B connected to the ring gear 3c is calculated from the rotation speed of the motor B and the torque Tr on the ring gear side, and in step S105, a predetermined charging power Wa is obtained from the remaining capacity of the battery 10. calculate. In step S106, a torque Tbat for power generation is calculated from the required power Wb of the motor B, the charging power Wa of the battery 10, and the rotation speed of the motor A. In step S107, the following equation (3) is obtained. Further, the driving torque Teg of the engine 1 is calculated by adding the sun gear side torque Ts and the power generation torque Tbat.
Teg = Ts + Tbat (3)
[0057]
Thereafter, the process proceeds to step S108, where it is determined whether or not the drive torque Teg calculated in step S107 described above can be output from the engine 1 from the generated power of the motor A and the output characteristics of the engine 1, and it is difficult to output the drive torque Teg. In this case, the rotational speed of the motor A is changed, a new rotational speed command is given to the motor A controller 21, and the power generation torque Tbat is calculated again from the necessary power Wb of the motor B, the charging power Wa of the battery 10, and the rotational speed of the motor A. And the driving torque Teg of the engine 1 is calculated by adding the power generation torque Tbat and the sun gear side torque Ts.
[0058]
In step S109, the torque Tr on the ring gear side is set as the torque of the motor B, and a torque command is given to the motor B controller 22 by multiplex communication. In step S110, a torque command of the drive torque Teg is given to the E / G_ECU 23 by multiplex communication. Proceed to
[0059]
In step S111, the travel by the motor B is controlled by the feedback value of the vehicle driving torque calculated based on the feedback values from the motor A controller 21, the motor B controller 22, and the E / G_ECU 23, and the routine is exited.
[0060]
That is, in the HEV_ECU 20, the reaction force (Tb) of the torque of the motor B based on the torque feedback value Ta ′ for power generation of the motor A received from the motor A controller 21 and the torque feedback value Tb ′ of the motor B received from the motor B controller 22 '× K (1-K)) is added and fed back to the E / G_ECU 23. In the E / G_ECU 23, the torque command value Teg from the HEV_ECU 20 and the feedback value (Ta' + Tb '× K / (1-K)) And the engine 1 is controlled.
[0061]
Then, the difference between the torque feedback value Teg ′ of the engine 1 and the torque feedback value Ta ′ of the motor A is added to the torque feedback value Tb ′ of the motor B to obtain the feedback value of the driver required torque, and the feedback of the driver required torque Based on the value (Tb ′ + Teg′−Ta ′), traveling control by the motor B is performed.
[0062]
As a result, in the low-load series traveling mode with a small required driving force, the power consumption of the battery 10 driven by the motor B can be supplemented while the reaction force of the motor B is supported by the engine 1 and the motor A. Constant torque traveling can be ensured.
[0063]
Next, transition control when switching from the series travel mode to the parallel travel mode will be described.
[0064]
The transition from the series travel mode to the parallel travel mode is performed by the transition control routine of FIG. 2. Before the lockup clutch 2 is engaged, the engine torque is gradually increased in advance to approach the driver request torque, and then the motor The rotation speed of A and the primary pulley rotation speed which is the input shaft rotation speed of the CVT 4 are matched, and the lockup clutch 2 is engaged.
[0065]
Specifically, first, in order to match the rotation speed Na of the motor A with the primary pulley rotation speed Np fed back from the T / M_ECU 24 in step S201, a rotation speed command is given to the motor A controller 21 by multiplex communication, and step S202. Thus, the actual rotational speed Nar of the motor A is detected from the rotational speed data fed back from the motor A controller 21.
[0066]
Next, the process proceeds to step S203, in which a predetermined value Tk is added to the current drive torque Teg to bring the drive torque Teg of the engine 1 closer to the driver required torque Tdrv during parallel running from the state of power generation torque or torque 0. The drive torque Teg is calculated (Teg ← Teg + Tk), and a torque command value of the drive torque Teg is given to the E / G_ECU 23 by multiplex communication in step S204.
[0067]
Thereafter, in step S205, it is checked whether or not the absolute value | Tdrv−Teg | of the difference between the driver request torque Tdrv and the engine drive torque Teg has become equal to or less than the set value Kt. As a result, | Tdrv−Teg |> Kt Sometimes the routine is exited and the process of increasing the engine command torque by a predetermined value Tk is continued. When | Tdrv−Teg | ≦ Kt, the routine proceeds to step S206, where the primary pulley rotational speed Np and the actual rotational speed Nar of the motor A are reached. It is checked whether or not the absolute value | Np−Nar |
[0068]
The set value Kn defines an allowable range in which the rotation speed of the motor A and the primary pulley rotation speed of the CVT 4 can be regarded as substantially matching. If | Np−Nar |> Kn in step S206, the routine is exited. The process of making the rotation of the motor A coincide with the rotation of the primary pulley by the rotation number command (Na = Np) to the motor A controller 21 is continued. At this time, the output torque of the motor A becomes negative by the control for increasing the driving torque of the engine 1 and the rotational speed control of the motor A to the primary pulley rotational speed Np.
[0069]
In step S206, when | Np−Nar | ≦ Kn and the actual rotational speed Nar of the motor A substantially coincides with the primary pulley rotational speed Np, the process proceeds to step S207, and the lock-up clutch is transmitted to the T / M_ECU 24 by multiplex communication. 2 is given, and in step S209, the series → parallel shift control completion flag FLAG2 is set and the routine is exited.
[0070]
As described above, when shifting from the series travel mode to the parallel travel mode, the drive torque of the engine 1 is gradually increased in advance to become the driver required torque in the parallel travel mode, and then the lockup clutch 2 is engaged. Since the clutch is engaged after the rotational speed of the motor A is substantially matched to the primary pulley rotational speed of the CVT 4 that is directly connected, the controllability of the rotational speed control for the motor A is improved, and rotational fluctuation and torque fluctuation are reduced. Not only can the clutch be engaged smoothly with a minimum, but the torque of the engine 1 does not need to be switched in a short time immediately after the clutch is engaged from the power generation torque in the series running or from the torque 0 state to the driver required torque. For this reason, the engine torque response delay is large relative to the motor torque. The shock caused by specific insufficient torque and torque excess can be avoided in advance.
[0071]
When the drive torque of the engine 1 is switched to the driver request torque immediately after the clutch is engaged, first, the output torque of the engine 1 is temporarily set to 0 immediately before the clutch is engaged, and the output torque of the engine 1 is changed from 0 immediately after the clutch is engaged. Since the output torque of the motor B must be switched from the driver request torque to 0 at the same time as switching to the driver request torque, the torque responsiveness between the two is different and the controllability is not necessarily good.
[0072]
On the other hand, in the present invention, at the time of transition from the series travel mode to the parallel travel mode, the drive torque of the engine 1 is gradually increased so as to become the driver required torque in the parallel travel mode, and then the rotational speed of the motor A Since the clutch is engaged after substantially matching the rotation speed of the pulley with the primary pulley, it is possible to exchange torque between the motors immediately after the lockup clutch 2 is engaged, and the controllability can be improved.
[0073]
That is, in the parallel running control routine of FIG. 4, when the lock-up clutch 2 is engaged and the mode is shifted from the series running mode, first, in step S301, a torque 0 command for setting the torque of the motor A to 0 is transmitted by multiplex communication to the motor A. This is given to the controller 21. In this case, immediately after the transition from the series travel mode to the parallel travel mode, that is, immediately after the lock-up clutch 2 is engaged, the torque of the motor B is simultaneously applied to the motor B controller 22 as the driving torque (driver required torque during the series travel). ) To give a torque command to make the torque zero once.
[0074]
As described above, in the transition control from the series travel mode to the parallel travel mode, the drive torque of the engine 1 is gradually increased to the driver request torque so that the rotational speed of the motor A substantially matches the primary rotational speed. Therefore, the motor A and the motor B are controlled with the torque 0 immediately after the shift to the parallel running, that is, immediately after the lockup clutch 2 is engaged, so that the negative output torque of the motor A can be reduced to the motor B. By controlling the torque to zero, it is absorbed through the planetary gear, and torque exchange between motors having the same torque response can be performed. Thereby, while reducing the shock at the time of clutch fastening, the durability of the clutch can be improved and the size of the clutch can be reduced.
[0075]
In the parallel travel mode, the lockup clutch 2 is engaged to couple the sun gear 3a of the planetary gear unit 3 and the carrier 3b, and the driving force of the motor B from the ring gear 3c is added to the driving force of the engine 1 from the sun gear 3a. Thus, since the output torque of the engine 1 and the motor B is transmitted as it is to the drive wheel side as it is output from the carrier 3b, the rotational speed of the motor A must be matched as much as possible, and control is difficult. In this case, if the motor A is kept in the rotational speed control in the series travel mode, the driving torque is absorbed by the motor A. On the other hand, if the rotational speed control of the motor A is stopped, the engine 1 and the motor B are caused by iron loss. Output torque is reduced.
[0076]
In any case, since it is difficult to control the vehicle drive torque in the parallel travel mode if the motor A remains in the rotational speed control in the series travel mode, the motor A controller that controls the rotational speed of the motor A in the parallel travel mode. By giving a torque 0 command to 21, the motor A is weakened by a field weakening or the like, and the torque of the engine 1 and the output torque of the motor B are input to the CVT 4 without loss.
[0077]
Then, after the motor A is operated at a torque of 0, the process proceeds to step S302, where the driver required torque Tdrv is calculated based on the accelerator opening Acc and the primary pulley rotation speed Np. Check if it is above. As a result, if the remaining capacity of the battery 10 is smaller than the predetermined value, a predetermined torque command is given to the E / G_ECU 23 by multiplex communication so that only the engine 1 runs according to the throttle opening in step S304. The process proceeds to S310.
[0078]
On the other hand, if the remaining capacity of the battery 10 is greater than or equal to the predetermined value in step S303, the process proceeds from step S303 to step S305, and the engine maximum output torque Tegmax is calculated from the throttle opening of the engine 1 and the primary pulley rotation speed Np of CVT4. To do. In step S306, a difference ΔT between the driver request torque Tdrv and the engine maximum output torque Tegmax is calculated (ΔT = Tdrv−Tegmax), and in step S307, the difference ΔT is set as the driving torque Tb of the motor B (Tb = ΔT).
[0079]
That is, in the parallel travel mode, when the driver required torque Tdrv is larger than the maximum output torque Tegmax determined from the equal throttle opening curve of the engine 1, the motor B assists the corresponding torque by (Tdrv− Tegmax) is the driving torque of the motor B.
[0080]
Thereafter, in step S308, a torque command for the engine maximum output torque Tegmax is given to the E / G_ECU 23 by multiplex communication. In step S309, a torque command for the drive torque Tb is given to the motor B controller 22 by multiplex communication. In step S310, the motor B controller The running control is performed using a value (Tb ′ + Teg ′) obtained by adding the torque feedback value Tb ′ of the motor B received from the motor 22 and the torque feedback value Teg ′ of the engine 1 received from the E / G_ECU 23 as a feedback value of the vehicle driving torque. , Exit the routine.
[0081]
In this parallel travel mode, torque distribution between the engine 1 and the motor B is determined, and travel by only the engine 1 or assist travel in which the engine 1 is assisted by the motor B is performed, but the motor A is changed from rotational speed control to torque control. The output torque of the engine 1 and the motor B can be transmitted to the drive wheel side without loss with simple commands and limited constant torque control without switching in earnest, and the drive torque can be easily controlled. .
[0082]
Next, the transition from the parallel travel mode to the series travel mode is performed by the transition control routine of FIG. In this routine, the torque of the engine 1 is gradually reduced and the corresponding torque is output from the motor B. When the torque of the engine 1 becomes zero, the torque 0 command of the motor A is canceled and the motor 1 The rotation speed of A is matched with the rotation speed of the motor B, and the lockup clutch 2 is released.
[0083]
That is, first, in step S401, a torque command of a torque value Teg (Teg = Teg−Teg / n) obtained by reducing the engine driving torque Teg by a predetermined ratio n is given to the E / G_ECU 23 by multiplex communication, and then step S401 is performed. In S402, the decrease Teg / n of the engine driving torque is added to the current driving torque Tb of the motor B to obtain a new driving torque Tb of the motor B (Tb + Tb / n), and a torque command for the new driving torque Tb. Is given to the motor B controller 22 by multiplex communication.
[0084]
Then, in step S403, it is checked whether or not the engine drive torque Teg has become 0. As a result, if Teg ≠ 0, the routine exits from step S403 and the torque of the engine 1 is decreased by a predetermined amount to reduce the torque of the motor B. The process of increasing the predetermined amount is repeated.
[0085]
After that, when the engine drive torque Teg becomes 0 in step S403, the process proceeds to step S404 to detect the rotational speed Nb of the motor B, and in step S405, the torque 0 command for the motor A to the motor A controller 21 is canceled and the motor A Is sent to the motor A controller 21 in order to set the rotation speed Na to the same rotation speed Nb as that of the motor B. In step S406, a command to release the lockup clutch 2 is given to the T / M_ECU 24 by multiplex communication. In step S407, the parallel → series shift control completion flag FLAG3 is set, and the routine is exited.
[0086]
That is, in the transition from the parallel traveling mode to the series traveling mode, the torque of the engine 1 is gradually brought close to 0 before releasing the lockup clutch 2 by combining the rotational speed of the motor A and the rotational speed of the motor B. Since the corresponding torque is output from the motor B, it is possible to shift from the parallel travel mode to the series travel mode without causing rotational fluctuation or torque fluctuation, and it is possible to prevent deterioration in driving feeling. .
[0087]
【The invention's effect】
As described above, according to the first aspect of the present invention, the lockup clutch is released. , Combining a part of the driving force of the engine and the driving force of the second motor From the series running mode to run , Engage the lock-up clutch Using at least the driving force of the engine When shifting to the parallel driving mode, the engine driving torque is gradually increased to shift to the driving torque in the parallel driving mode. Furthermore, after controlling the rotational speed command of the first motor, Since the lockup clutch is engaged by substantially matching the rotation speed of the first motor with the input shaft rotation speed of the power conversion mechanism, rotational fluctuations and torque fluctuations associated with engagement / release of the lockup clutch are minimized. Not only can the clutch be engaged smoothly, but it is not necessary to switch the engine torque to the torque in the parallel running mode in a short time immediately after the clutch is engaged. A shock due to a transient lack of torque or excessive torque can be avoided in advance.
[0088]
In the second aspect of the invention, the transition from the series travel mode to the parallel travel mode is performed in the same manner as in the first aspect of the invention, and when the parallel travel mode is shifted to the series travel mode, the engine drive torque , And the second motor drive torque is gradually increased by an amount corresponding to the decrease in the engine drive torque, and the rotational speed of the second motor when the engine drive torque becomes substantially zero. After controlling the rotational speed command of the first motor, Since the lock-up clutch is released, a shock can be prevented in both cases of locking and releasing the lock-up clutch, driving feeling can be further improved, and smooth running can be realized.
[Brief description of the drawings]
FIG. 1 is a flowchart showing a switching determination routine between a series travel mode and a parallel travel mode.
FIG. 2 is a flowchart showing a control routine in a series travel mode.
FIG. 3 is a flowchart showing a transition control routine from a series travel mode to a parallel travel mode.
FIG. 4 is a flowchart showing a control routine in a parallel travel mode.
FIG. 5 is a flowchart showing a transition control routine from a parallel travel mode to a series travel mode.
FIG. 6 is an explanatory diagram of a driver request torque map
FIG. 7 is an explanatory diagram showing a relationship between a vehicle speed for clutch engagement / disengagement determination and a driver requested torque.
FIG. 8 is an explanatory diagram showing the configuration of a drive control system
[Explanation of symbols]
1 ... Engine
2 ... Lock-up clutch
3 ... Planetary gear unit (single pinion type planetary gear)
3a Sun gear
3b ... Career
3c ... Ring gear
4 ... Belt type continuously variable transmission (power conversion mechanism)
A ... 1st motor
B ... Second motor
20 ... HEV_ECU

Claims (2)

A first motor connected between the output shaft of the engine and the sun gear of the single pinion planetary gear, a second motor connected to the ring gear of the planetary gear, and a lockup for fastening and releasing the sun gear and the carrier of the planetary gear. A hybrid vehicle including a clutch and a power conversion mechanism that is connected to the planetary gear carrier and performs gear shifting and torque amplification between the planetary gear and the drive wheel in accordance with a gear ratio that can be switched between a plurality of stages or continuously. A traveling mode is a series traveling mode in which the lockup clutch is released and a part of the driving force of the engine and the driving force of the second motor are combined, and the lockup clutch is engaged, and at least switching to a parallel running mode in which the vehicle travels using the driving force of the engine A control apparatus for a hybrid vehicle changing,
When shifting from the series travel mode to the parallel travel mode, the engine drive torque is gradually increased to shift to the drive torque in the parallel travel mode , and the first motor is subjected to rotational speed command control. in the rotational speed of the first motor substantially match with the input shaft rotating speed of the power conversion mechanism, the hybrid vehicle control apparatus characterized by comprising a means for engagement of the lock-up clutch. At the time of transition from the parallel traveling mode to the series traveling mode, the engine driving torque is gradually decreased and the driving torque of the second motor is gradually increased by the decrease of the engine driving torque. Means for releasing the lockup clutch after controlling the rotational speed command of the first motor with the rotational speed of the second motor when the driving torque of the engine becomes substantially zero. The hybrid vehicle control device according to claim 1.

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