JPWO2014181616A1 - Control device for hybrid vehicle - Google Patents

Abstract

In the present invention, in a control device for a hybrid vehicle that includes an engine and a motor generator and travels while charging the battery with the electric power generated by the motor generator using the engine torque, a request is made when the charge amount of the battery is a predetermined value or more. When the drive torque is less than or equal to the predetermined torque, the power generation torque by the motor generator is increased, and when the required drive torque is greater than the predetermined torque, the power generation torque by the motor generator is decreased.

Description

  The present invention relates to a control apparatus for a hybrid vehicle that can travel while generating power using an engine and a motor generator as a power source.

  As such a hybrid vehicle, conventionally, for example, a vehicle described in Patent Document 1 is known. In this publication, when an engine is driven and power is generated by a motor generator, the power generation amount in a low rotation region with low fuel efficiency is reduced (or stopped), and the power generation amount in a rotation region with high fuel efficiency is increased. A power generation torque characteristic is set. The power generation efficiency is improved by moving the basic power generation torque characteristics in the torque axis direction according to the state of charge of the battery.

JP 2006-341708 A

  However, in the technique described in Patent Document 1, since the basic power generation torque characteristic is moved in the torque direction according to the battery SOC, a constant power generation torque is added when traveling by engine driving force. Even if the engine efficiency is improved, the magnitude of the driving force is generated, so that a highly efficient engine operation cannot be achieved, and it is difficult to sufficiently improve the power generation efficiency.

  An object of the present invention is to provide a control device for a hybrid vehicle capable of improving the power generation efficiency by paying attention to the above-mentioned problem.

  For this purpose, in the present invention, in a control device for a hybrid vehicle that includes an engine and a motor generator and travels while charging the battery with the electric power generated by the motor generator using the engine torque, the charge amount of the battery is a predetermined value. In the above case, the power generation torque by the motor generator is increased when the required drive torque is less than or equal to the predetermined torque, and the power generation torque by the motor generator is decreased when the required drive torque is greater than the predetermined torque.

  Therefore, by increasing the power generation torque when the required drive torque is small and decreasing the power generation torque when the required drive torque is large, an efficient operating point is ensured as the engine operating point even when the required drive torque is small. Can increase engine efficiency.

1 is an overall system diagram illustrating a hybrid vehicle according to a first embodiment. FIG. 3 is a block diagram illustrating a control configuration of the hybrid vehicle according to the first embodiment. 2 is a target driving force map according to the first embodiment. 3 is a flowchart illustrating a power generation torque control process according to the first embodiment. 3 is a power generation amount map showing a relationship of power generation amount with respect to the SOC of the first embodiment. 2 is an operating point map defined by the engine torque and the engine speed of the first embodiment. It is a time chart showing the relationship between the driving torque and the power generation torque when the SOC exceeds a predetermined value.

DESCRIPTION OF SYMBOLS 10 Integrated controller 16 Accelerator opening sensor 17 Vehicle speed sensor 21 Motor rotation speed sensor
AT automatic transmission
CL1 1st clutch
CL2 2nd clutch E engine
MG motor generator
RR, RL drive wheel

[Example 1]
First, the drive system configuration of the hybrid vehicle will be described. FIG. 1 is an overall system diagram showing a hybrid vehicle by rear wheel drive to which the engine start control device of the first embodiment is applied. As shown in FIG. 1, the drive system of the hybrid vehicle in the first embodiment includes an engine E, a first clutch CL1, a motor generator MG, a second clutch CL2, an automatic transmission AT, a propeller shaft PS, It has a differential DF, a left drive shaft DSL, a right drive shaft DSR, a left rear wheel RL (drive wheel), and a right rear wheel RR (drive wheel). FL is the front left wheel and FR is the front right wheel.

  The engine E is, for example, a gasoline engine, and the valve opening degree of the throttle valve and the like are controlled based on a control command from an engine controller 1 described later. The engine output shaft is provided with a flywheel FW.

  The first clutch CL1 is a clutch interposed between the engine E and the motor generator MG, and the control created by the first clutch hydraulic unit 6 based on a control command from the first clutch controller 5 described later. Actuated by hydraulic pressure, and fastening / release including slip fastening is controlled.

  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 the three-phase AC generated by the inverter 3 is generated based on a control command from a motor controller 2 described later. It is controlled by applying. The motor generator MG can operate as an electric motor that is driven to rotate by receiving power supplied from the battery 4 (hereinafter, this state is referred to as “power running”), or when the rotor is rotated by an external force. Can function as a generator that generates electromotive force at both ends of the stator coil to charge the battery 4 (hereinafter, this operation state is referred to as “regeneration”). Note that the rotor of the motor generator MG is connected to the input shaft of the automatic transmission AT via a damper (not shown).

  The second clutch CL2 is a clutch interposed between the motor generator MG and the left and right rear wheels RL and RR, and is generated by the second clutch hydraulic unit 8 based on a control command from the AT controller 7 described later. The fastening / release including slip fastening is controlled by the control hydraulic pressure.

  The automatic transmission AT is a transmission that automatically switches the stepped gear ratio, such as forward 7 speed, reverse 1 speed, etc. according to the vehicle speed, accelerator opening, etc., and the second clutch CL2 is newly added as a dedicated clutch However, some frictional engagement elements are used among a plurality of frictional engagement elements that are engaged at each gear stage of the automatic transmission AT.

  The output shaft of the automatic transmission AT is connected to the left and right rear wheels RL and RR via a propeller shaft PS, a differential DF, a left drive shaft DSL, and a right drive shaft DSR as vehicle drive shafts. The first clutch CL1 and the second clutch CL2 are, for example, wet multi-plate clutches that can continuously control the oil flow rate and hydraulic pressure with a proportional solenoid.

  This hybrid drive system has three travel modes according to the engaged / released state of the first clutch CL1. The first travel mode is an electric vehicle travel mode (hereinafter abbreviated as “EV travel mode”) as a motor use travel mode that travels using only the power of the motor generator MG as a power source with the first clutch CL1 opened. It is. The second travel mode is an engine use travel mode (hereinafter, abbreviated as “HEV travel mode”) in which the first clutch CL1 is engaged and the engine E is included in the power source. In the third travel mode, the second clutch CL2 is slip-controlled while the first clutch CL1 is engaged, and the engine travel slip travel mode (hereinafter referred to as “WSC travel mode”) is performed while the engine E is included in the power source. ). This mode is a mode in which creep running can be achieved particularly when the battery SOC is low or the engine water temperature is low. Here, the SOC represents the state of charge of the battery. When the SOC is high, the amount of charge of the battery is high, and when the SOC is low, the state of charge of the battery is low. When transitioning from the EV travel mode to the HEV travel mode, the first clutch CL1 is engaged and the engine is started using the torque of the motor generator MG.

  The “HEV travel mode” has three travel modes of “engine travel mode”, “motor assist travel mode”, and “travel power generation mode”. In the “engine running mode”, the drive wheels are moved using only the engine E as a power source. In the “motor-assisted travel mode”, the drive wheels are moved using the engine E and the motor generator MG as power sources. In the “traveling power generation mode”, the motor generator MG is caused to function as a power generator while the drive wheels RR and RL are moved using the engine E as a power source.

  During constant speed operation or acceleration operation, motor generator MG is operated as a generator using the power of engine E. Further, during deceleration operation, the braking energy is regenerated and generated by the motor generator MG and used for charging the battery 4. Further, as a further mode, there is a power generation mode in which the motor generator MG is operated as a generator using the power of the engine E when the vehicle is stopped.

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

  The engine controller 1 inputs the engine speed information from the engine speed sensor 12, and controls the engine operating point (Ne: engine speed, Te: engine torque) according to the target engine torque command from the integrated controller 10, etc. For example, to a throttle valve actuator (not shown). Information such as the engine speed Ne is supplied to the integrated controller 10 via the CAN communication line 11.

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

  The first clutch controller 5 inputs sensor information from the first clutch hydraulic pressure sensor 14 and the first clutch stroke sensor 15, and according to the first clutch control command from the integrated controller 10, the first clutch CL1 is engaged / released. A command to control is output to the first clutch hydraulic unit 6. Information on the first clutch stroke C1S is supplied to the integrated controller 10 via the CAN communication line 11.

  The AT controller 7 inputs sensor information from the accelerator opening sensor 16, the vehicle speed sensor 17, the second clutch hydraulic pressure sensor 18, and an inhibitor switch that outputs a signal corresponding to the position of the shift lever operated by the driver. 10 is output to the second clutch hydraulic unit 8 in the AT hydraulic control valve in response to the second clutch control command from 10. Information on the accelerator pedal opening APO, the vehicle speed VSP, and the inhibitor switch is supplied to the integrated controller 10 via the CAN communication line 11.

  The brake controller 9 inputs sensor information from a wheel speed sensor 19 and a brake stroke sensor 20 that detect the wheel speeds of the four wheels. For example, when the brake is depressed, braking is performed with respect to the required braking force obtained from the brake stroke BS. When the braking force alone is insufficient, the regenerative cooperative brake control is performed based on the regenerative cooperative control command from the integrated controller 10 so that the shortage is supplemented by the mechanical braking force (braking force by the friction brake).

  The integrated controller 10 manages the energy consumption of the entire vehicle and has a function for running the vehicle with the highest efficiency. The integrated controller 10 detects the motor rotational speed Nm, and the second clutch output rotational speed N2out. A second clutch output speed sensor 22 for detecting the second clutch, a second clutch torque sensor 23 for detecting the second clutch transmission torque capacity TCL2, a brake hydraulic pressure sensor 24, and a temperature sensor 10a for detecting the temperature of the second clutch CL2. The information from the G sensor 10b for detecting the longitudinal acceleration and the information obtained through the CAN communication line 11 are input. The integrated controller 10 also controls the operation of the engine E according to the control command to the engine controller 1, the operation control of the motor generator MG based on the control command to the motor controller 2, and the first control command to the first clutch controller 5. Engagement / release control of the clutch CL1 and engagement / release control of the second clutch CL2 by a control command to the AT controller 7 are performed.

  Below, the control calculated by the integrated controller 10 of Example 1 is demonstrated using the block diagram shown in FIG. For example, this calculation is performed by the integrated controller 10 every control cycle of 10 msec. The integrated controller 10 includes a target driving force calculation unit 100, a mode selection unit 200, a target charge / discharge calculation unit 300, an operating point command unit 400, and a shift control unit 500.

  The target driving force calculation unit 100 calculates a target driving force tFoO from the accelerator pedal opening APO and the vehicle speed VSP using the target driving force map shown in FIG. The mode selection unit 200 selects a travel mode based on a vehicle speed and an accelerator pedal opening from a shift diagram having a mode region provided in advance. The mode area includes an EV travel mode, a WSC travel mode, and an HEV travel mode, and the target mode is calculated from the accelerator pedal opening APO and the vehicle speed VSP. However, even if the EV travel mode is selected, if the battery SOC is equal to or lower than the predetermined value, the “HEV travel mode” or the “WSC travel mode” is forcibly set as the target mode. Target charge / discharge calculation section 300 calculates target charge / discharge power tP from battery SOC using a preset target charge / discharge amount map. Further, the power generation torque is controlled according to the battery SOC. Details will be described later.

The operating point command unit 400 uses the accelerator pedal opening APO, the target driving force tFoO, the target mode, the vehicle speed VSP, and the target charging / discharging power tP as a target for reaching the operating point, as a transient target engine torque. And a target motor generator torque, a target second clutch engagement capacity, a target gear position of the automatic transmission AT, and a first clutch solenoid current command which is a transmission torque capacity command of the first clutch CL1. In addition, the operating point command unit 400 is provided with an engine start control unit 401 that engages the first clutch CL1 and starts the engine E when transitioning from the EV travel mode to the HEV travel mode.
The shift control unit 500 drives and controls the solenoid valve in the automatic transmission AT so as to achieve the target second clutch engagement capacity and the target shift speed according to the shift schedule set in the shift diagram described above.

FIG. 4 is a flowchart illustrating a power generation torque control process according to the first embodiment. Here, a process of controlling the power generation torque in accordance with the SOC when the vehicle is traveling in the HEV travel mode while generating power with the motor generator MG by the driving force of the engine E is shown.
In step S1, the engine speed is read.
In step S2, the SOC that is the remaining battery capacity is read.

  In step S3, the target engine efficiency is set based on the SOC. FIG. 5 is a power generation amount map showing the relationship of the power generation amount Pb to the SOC. When the SOC is less than the predetermined value SOC1, a certain large amount of power generation is required. On the other hand, when the SOC is equal to or greater than the predetermined value SOC1, the power generation amount Pb is set to be smaller as the SOC is larger in order to satisfy the energy management requirements. To improve energy efficiency. FIG. 6 is an operating point map defined by the engine torque and the engine speed. In the map, apart from the high-efficiency operation line in which the engine operating point is normally set, a target engine efficiency line corresponding to the SOC is set, and the efficiency is set to decrease as the SOC increases. In other words, the target engine efficiency line is set such that the engine efficiency decreases as the power generation amount Pb is suppressed.

In step S4, a target engine torque Tet, which is a point where the target engine equiefficiency line and the current engine speed intersect, is determined.
In step S5, the required drive torque Ted necessary for traveling is read based on the driver's request.
In step S6, it is determined whether or not the required drive torque Ted is larger than the target engine torque Tet. If larger, the process proceeds to step S7, and if Ted ≦ Tet, the process proceeds to step S8.
In step S7, the power generation torque Teg is set to zero. That is, all the engine torque is transmitted to the drive wheels. Specifically, as shown in the map of FIG. 6, when the requested drive torque is larger than the target engine torque, the requested drive torque Ted is output as the engine torque without generating power.
In step S8, a difference (= Tet−Ted) between the target engine torque and the required drive torque Ted is set as the power generation torque Teg of the motor generator MG. Specifically, as shown in the map of FIG. 6, when the required drive torque Ted is smaller than the target engine torque, the target engine torque Tet and the drive torque Ted are output while outputting the drive torque Ted to the drive wheels. The motor generator MG is generated based on the difference.
In step S9, the motor generator MG is commanded with a power generation torque Ted.

  FIG. 7 is a time chart showing the relationship between the driving torque and the power generation torque when the SOC exceeds a predetermined value. The upper time chart in FIG. 7 is a comparative example in which the power generation torque according to the SOC is simply added to the drive torque, and the lower time chart in FIG. 7 is the case where the power generation control of the first embodiment is performed. It is a time chart. The solid line in FIG. 7 represents the engine torque, the alternate long and short dash line represents the drive torque, and the space between the engine torque and the drive torque represents the power generation torque Ted.

  As shown in the comparative example, since the predetermined SOC1 was exceeded at time t0, when the power generation amount Pb is suppressed, the controlled power generation torque is controlled by being added to the drive torque. In this case, when the driving torque is small, the engine torque is also low, and therefore, there is a problem that the engine operating point comes in a region where the engine efficiency is poor.

On the other hand, in the first embodiment, after time t0, the target engine efficiency is set as the engine operating point, the operation is continued in a region where the engine torque is not so low, and the requested driving torque is output within the range. In addition, overall engine efficiency can be improved by setting the power generation torque Teg to the difference between the target engine torque and the required drive torque Ted.
Further, as shown at time t1, when the required drive torque Ted is larger than the target engine torque Tet, the power generation amount Pb is set to 0, and the drive torque Ted required as the engine torque is output as the engine torque. When the necessary drive torque Ted becomes smaller than the target engine torque Tet at time t2, the power generation amount Pb is set again as the power generation torque Teg to the difference between the target engine torque and the necessary drive torque Ted. As a result, by setting the power generation torque to 0, all of the engine torque can be utilized as the drive torque, and the engine efficiency can be improved.

As described above, the effects listed below are obtained in the first embodiment.
(1) In a control apparatus for a hybrid vehicle that includes an engine E and a motor generator MG and travels while charging the battery 4 with electric power generated by the motor generator MG using engine torque.
When SOC (battery charge) is SOC1 (predetermined value) or more, when the required drive torque Ted is less than the target engine torque Tet (predetermined torque), the power generation torque Teg by the motor generator MG is increased, and the required drive torque Ted is When the torque is larger than the predetermined torque, the power generation torque Teg by the motor generator is reduced (power generation torque control means).
Therefore, when the required drive torque Ted is small, the power generation torque Teg is increased.When the required drive torque Ted is large, the power generation torque Teg is decreased. A good operating point can be secured and the engine efficiency can be increased.

(2) The target engine torque Tet (predetermined torque) is a torque defined by a preset target engine equiefficiency line and the current engine speed, and when the required drive torque Ted is less than or equal to the target engine torque Tet The engine torque is increased to the target engine torque Tet, and the power generation torque Teg by the motor generator MG is set as a differential torque between the target engine torque Tet and the required drive torque Ted.
Therefore, the engine efficiency can be increased by controlling the power generation torque Teg along the preset engine efficiency.

  (3) The target engine iso-efficiency line is set to lower engine efficiency as the SOC increases. Therefore, it is possible to improve energy efficiency in consideration of necessary power and power generation efficiency of the entire vehicle.

  (4) When the required drive torque Ted is larger than the predetermined torque, the power generation torque by the motor generator MG is set to zero. Therefore, the engine torque can be fully utilized as the drive torque, and the engine efficiency can be improved.

[0002]
In a hybrid vehicle control device that travels while charging the battery with the electric power generated by the motor generator using engine torque, the target engine efficiency line is set and set so that the engine efficiency decreases as the battery charge increases. The target engine torque is set based on the target engine iso-efficiency line and the current engine speed. If the requested drive torque based on the driver's request is less than or equal to the target engine torque, the engine torque is set as the target engine torque, If the drive torque is greater than the target engine torque, the engine torque is the required drive torque. If the required drive torque is less than or equal to the target engine torque, the power generation torque by the motor generator is the differential torque between the target engine torque and the required drive torque. Torque is the target engine torque If Ri is greater, the power generation torque to zero.
Effects of the Invention [0007]
Therefore, even when the required drive torque is small, it is possible to continue the operation in the region where the engine torque is not so low and to secure a relatively efficient operating point as the operating point of the engine. Energy efficiency can be improved.
BRIEF DESCRIPTION OF THE DRAWINGS [0008]
FIG. 1 is an overall system diagram showing a hybrid vehicle according to a first embodiment.
FIG. 2 is a block diagram showing a control configuration of the hybrid vehicle of the first embodiment.
FIG. 3 is a target driving force map according to the first embodiment.
FIG. 4 is a flowchart showing a power generation torque control process according to the first embodiment.
FIG. 5 is a power generation amount map showing the relationship of the power generation amount to the SOC of the first embodiment.
FIG. 6 is an operating point map defined by the engine torque and engine speed of the first embodiment.
FIG. 7 is a time chart showing the relationship between drive torque and power generation torque when SOC exceeds a predetermined value.
Explanation of symbols [0009]
DESCRIPTION OF SYMBOLS 10 Integrated controller 16 Accelerator opening degree sensor 17 Vehicle speed sensor 21 Motor rotation speed sensor AT Automatic transmission CL1 1st clutch

For this purpose, in the present invention, in a control device for a hybrid vehicle that includes an engine and a motor generator and travels while charging the battery with the electric power generated by the motor generator using the engine torque, the larger the charge amount of the battery, A target engine iso-efficiency line is set so that the engine efficiency is lowered, a target engine torque is set based on the set target engine iso-efficiency line and the current engine speed, and a required drive torque based on the driver's request Is the target engine torque, the engine torque is the required engine torque when the required drive torque is greater than the target engine torque, and the motor generator generates power when the required drive torque is less than the target engine torque. Torque is required with target engine torque The difference torque between the drive torque, the required drive torque is higher than the target engine torque is the generator torque to zero.

Claims (4)

In a control apparatus for a hybrid vehicle that includes an engine and a motor generator and travels while charging the battery with electric power generated by the motor generator using engine torque,
When the charge amount of the battery is greater than or equal to a predetermined value, the power generation torque by the motor generator is increased when the required drive torque is less than the predetermined torque, and the power generation torque by the motor generator is decreased when the required drive torque is greater than the predetermined torque A control device for a hybrid vehicle, comprising: a power generation torque control means for causing the power generation torque to be controlled. In the hybrid vehicle control device according to claim 1,
The predetermined torque is a target engine torque defined by a preset target engine isoefficiency line and the current engine speed. When the required drive torque is equal to or less than the predetermined torque, the engine torque is increased to the predetermined torque. And a power generation torque generated by the motor generator as a differential torque between the target engine torque and the required drive torque. In the hybrid vehicle control device according to claim 2,
The control device for a hybrid vehicle, wherein the power generation torque control means sets the target engine efficiency line to a lower engine efficiency as the charge amount of the battery is larger. In the hybrid vehicle control device according to any one of claims 1 to 3,
The power generation torque control means sets the power generation torque generated by the motor generator to 0 when the required drive torque is greater than a predetermined torque.

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