JP2010158937A - Device for controlling hybrid vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device for controlling a hybrid vehicle capable of suppressing an electricity circulation ratio, and capable of improving fuel consumption. <P>SOLUTION: The device for controlling the hybrid vehicle includes: a driving force synthesis transmission TM which has a Ravigneaux type planetary gear train PGR configured by connecting an engine E, a first motor generator MG1, a second motor generator MG2 and an output gear OG to rotary elements, respectively. The device for controlling the hybrid vehicle includes: a battery 4 which transmits and receives power to/from the first and second motor generators; and an integrated controller 6 which calculates the charging and discharging power of the battery 4 for obtaining the change gear ratio of the driving force synthesis transmission TM so that an electric loss, to be generated when driving the second motor generator MG2 or the first motor generator MG1 with the generated power of the first motor generator MG1 or the second motor generator MG2, becomes minimum, and which controls the engine E and the first and second motor generators MG1 and MG2 so that the calculated charging and discharging power is set. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a control device for a hybrid vehicle.

  In the conventional hybrid vehicle control device, a part of the engine output is supplied to the first motor generator via a transmission constituted by planetary gears, and the second motor generator is driven by the electric power generated by the first motor generator. It is transmitted to the drive shaft. An example of a technique related to the above description is described in Patent Document 1.

Japanese Patent No. 32020115

  However, in the above prior art, the ratio at which engine power is electrically converted, that is, the electrical circulation ratio, depends on the transmission gear ratio (the ratio between the input rotation speed and the output rotation speed). The efficiency of the machine changes. Here, since the gear ratio is set in accordance with the vehicle speed, even when a desired engine operating point at which the fuel efficiency of the engine is the best is set, the electric circulation ratio increases depending on the vehicle speed, and the electric loss is reduced. There was a problem that the fuel consumption deteriorated due to the increase.

  An object of the present invention is to provide a control device for a hybrid vehicle that can suppress an electric circulation ratio and improve fuel efficiency.

  In order to solve the above problems, in the present invention, the charge / discharge power of a battery that obtains the gear ratio of the differential gear transmission that minimizes the electric loss that occurs when the second motor generator is driven by the generated power of the first motor generator. And the engine and both motor generators are controlled so as to obtain this charge / discharge power.

  Therefore, in the present invention, since the battery is charged and discharged so that the electric loss is minimized, the electric circulation ratio can be suppressed and the fuel efficiency can be improved.

1 is an overall system diagram showing a hybrid vehicle to which an engine operating point control device of Embodiment 1 is applied. It is a collinear diagram showing each driving mode by the Ravigneaux type planetary gear train adopted in the hybrid vehicle to which the engine operating point control device of the first embodiment is applied. It is a figure which shows an example of the driving mode map in the hybrid vehicle to which the engine operating point control apparatus of Example 1 is applied. It is a figure which shows the mode transition path | route between the four driving modes in the hybrid vehicle to which the engine operating point control apparatus of Example 1 is applied. FIG. 6 is a control block diagram for determining an engine operating point in the integrated controller 6 according to the first embodiment of the first embodiment. It is a figure which shows the relationship between the gear ratio of the driving force synthetic | combination transmission TM of Example 1, and an electrical circulation ratio. It is a figure which shows the relationship between the engine speed of Example 1, and an electrical circulation ratio.

  EMBODIMENT OF THE INVENTION Hereinafter, the form for implementing the control apparatus of the hybrid vehicle of this invention is demonstrated based on the Example shown on drawing.

First, the drive system configuration of the hybrid vehicle will be described.
FIG. 1 is an overall system diagram showing a drive system of a hybrid vehicle to which the hybrid vehicle 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 motor generator MG1, a second motor generator MG2, an output gear OG (output member), and a driving force synthesis transmission. (Differential gear transmission) TM.

The engine E is a gasoline engine or a diesel engine, and the opening degree of the throttle valve and the like are controlled based on a control command from an engine controller 1 described later.
The first motor generator MG1 and the second motor generator MG2 are synchronous motor generators in which a permanent magnet is embedded in a rotor and a stator coil is wound around a stator. Based on a control command from a motor controller 2 described later, an inverter 3 Are controlled independently by applying the three-phase alternating current produced by

  The driving force synthesis transmission TM has a Ravigneaux type planetary gear train PGR (planetary gear train) and a low brake LB. The Ravigneaux planetary gear train PGR includes a first sun gear S1, a first pinion P1, and a first gear. 1 ring gear R1, 2nd sun gear S2, 2nd pinion P2, 2nd ring gear R2, and common carrier PC which supports 1st pinion P1 and 2nd pinion P2 which mutually mesh | engage. . That is, the Ravigneaux type planetary gear PGR has five rotating elements: the first sun gear S1, the first ring gear R1, the second sun gear S2, the second ring gear R2, and the common carrier PC. The connection relationship of the input / output members with respect to these five rotating elements will be described.

  A first motor generator MG1 is connected to the first sun gear S1. The first ring gear R1 is provided so as to be fixed to the case via the low brake LB. A second motor generator MG2 is connected to the second sun gear S2. The engine E is connected to the second ring gear R2 (engine input member) via an engine clutch EC. The output gear OG is directly connected to the common carrier PC. A driving force is transmitted from the output gear OG to the left and right drive tires (drive wheels) via a differential and drive shaft (not shown).

  Due to the above connection relationship, the first motor generator MG1 (first sun gear S1), the engine E (second ring gear R2), the output gear OG (common carrier PC), the low brake LB ( It is possible to introduce a rigid lever model that is arranged in the order of the first ring gear R1) and the second motor generator MG2 (second sun gear S2) and can simply express the dynamic operation of the Ravigneaux planetary gear train PGR.

  Here, the “collinear diagram” is a velocity diagram used in a simple and easy-to-understand method of drawing instead of the method of obtaining by equation when considering the gear ratio of the differential gear. The rotational speed of the rotating element (rotational speed) is taken, each rotating element is taken on the horizontal axis, and the interval between the rotating elements is arranged so as to be a collinear lever ratio based on the gear ratio of the sun gear and ring gear. is there.

  The engine clutch EC and the low brake LB are a multi-plate friction clutch and a multi-plate friction brake that are fastened by hydraulic pressure from a hydraulic control device 5 to be described later. The engine clutch EC is the engine E in the collinear diagram of FIG. In addition, the low brake LB is disposed at a position that coincides with the rotational speed axis of the second ring gear R2 that is the engine input rotating member. The low brake LB is the rotational speed axis (output gear) of the first ring gear R1 on the collinear diagram of FIG. (Position between the rotational speed axis of OG and the rotational speed axis of the second sun gear S2).

Next, the control system of the hybrid vehicle will be described.
As shown in FIG. 1, the control system of the hybrid vehicle in the first embodiment includes an engine controller 1, a motor controller 2, an inverter 3, a battery 4, a hydraulic control device 5, and an integrated controller 6 (control means). An accelerator opening sensor 7, a vehicle speed sensor 8, an engine speed sensor 9, a first motor generator speed sensor 10, a second motor generator speed sensor 11, a second ring gear speed sensor 12, It is comprised.

  The engine controller 1 responds to a target engine torque command or the like from the integrated controller 6 that inputs the accelerator opening APO from the accelerator opening sensor 7 and the engine speed Ne from the engine speed sensor 9. A command for controlling Te) is output to, for example, a throttle valve actuator (not shown).

  The motor controller 2 operates the motor operation of the first motor generator MG1 in response to a target motor generator torque command from the integrated controller 6 that inputs the motor generator rotation speeds N1 and N2 from both the motor generator rotation speed sensors 10 and 11 by the resolver. A command for independently controlling the point (N1, T1) and the motor operating point (N2, T2) of the second motor generator MG2 is output to the inverter 3. The motor controller 2 outputs information on the battery SOC indicating the state of charge of the battery 4 to the integrated controller 6.

The inverter 3 is connected to the stator coils of the first motor generator MG1 and the second motor generator MG2, and generates an independent three-phase alternating current according to a command from the motor controller 2. The inverter 3 is connected to a battery 4 that is discharged during power running and charged during regeneration.
The hydraulic control device 5 receives a hydraulic command from the integrated controller 6 and performs engagement hydraulic pressure control and release hydraulic pressure control of the engine clutch EC and the low brake LB. The engagement hydraulic pressure control and the release hydraulic pressure control include a half-clutch control based on a slip engagement control and a slip release control.

  The integrated controller 6 includes an accelerator opening APO from the accelerator opening sensor 7, a vehicle speed VSP from the vehicle speed sensor 8, an engine speed Ne from the engine speed sensor 9, and a first motor generator speed sensor 10. Information such as the first motor generator rotational speed N1, the second motor generator rotational speed N2 from the second motor generator rotational speed sensor 11, and the second ring gear input rotational speed ωin from the second ring gear rotational speed sensor 12 Input and perform predetermined arithmetic processing. Then, a control command is output to the engine controller 1, the motor controller 2, and the hydraulic control device 5 according to the calculation processing result.

  The integrated controller 6 and the engine controller 1 and the integrated controller 6 and the motor controller 2 are connected by bidirectional communication lines 14 and 15 for information exchange, respectively.

Next, the travel mode of the hybrid vehicle will be described.
The travel modes in the hybrid vehicle of the first embodiment include an electric vehicle continuously variable transmission mode (hereinafter referred to as “EV mode”), an electric vehicle fixed transmission mode (hereinafter referred to as “EV-LB mode”), and a hybrid. It has a vehicle fixed speed change mode (hereinafter referred to as “LB mode”) and a hybrid vehicle continuously variable speed change mode (hereinafter referred to as “E-iVT mode”).

  “EV mode” is a continuously variable transmission mode that runs with only two motor generators MG1 and MG2, as shown in the collinear diagram of FIG. 2 (a). Engine E is stopped and engine clutch EC is released. is there.

  The “EV-LB mode” is a fixed speed change mode in which only the two motor generators MG1 and MG2 run with the low brake LB engaged, as shown in the collinear diagram of FIG. Is stopped and the engine clutch EC is released. Since the reduction ratio from the first motor generator MG1 to the output Output and the reduction ratio from the second motor generator MG2 to the output Output are large, this is a mode in which a large driving force is generated.

  As shown in the collinear diagram of FIG. 2 (c), the “LB mode” is a fixed speed change mode in which the engine E and the motor generators MG1 and MG2 run while the low brake LB is engaged. And the engine clutch EC is concluded. This is a mode in which the driving force is large because the reduction ratio from engine E and motor generators MG1, MG2 to output Output is large.

  “E-iVT mode” is a continuously variable transmission mode that runs on engine E and motor generators MG1 and MG2, as shown in the nomograph of FIG. 2 (d). Engine E is operated and engine clutch EC is engaged. It is.

  Then, the mode transition control of the four travel modes is performed by the integrated controller 6. That is, the integrated controller 6 has a driving mode map in which four driving modes as shown in FIG. 3 are allocated in advance in a three-dimensional space by the required driving force Fdrv obtained from the accelerator opening APO and the like, the vehicle speed VSP, and the battery SOC. When the vehicle is stopped or running, the driving mode map is searched based on the detected values of the required driving force Fdrv, vehicle speed VSP, and battery SOC, and the vehicle operating point and battery charging determined by the required driving force Fdrv and vehicle speed VSP. The optimum driving mode is selected according to the amount. FIG. 3 is an example of a travel mode map that is represented in two dimensions by the required driving force Fdrv and the vehicle speed VSP by cutting out the three-dimensional travel mode map at a value with a sufficient capacity range of the battery SOC.

  When the mode transition is performed between the “EV mode” and the “EV-LB mode” by selecting the travel mode map, the low brake LB is engaged / released as shown in FIG. When mode transition is performed between the “E-iVT mode” and the “LB mode”, the low brake LB is engaged / released as shown in FIG. Further, when mode transition is performed between the “EV mode” and the “E-iVT mode”, the engagement / release of the engine clutch EC and the start / stop of the engine E are performed as shown in FIG. When mode transition is performed between the “EV-LB mode” and the “LB mode”, the engagement / release of the engine clutch EC and the start / stop of the engine E are performed as shown in FIG.

Next, a method for determining the engine operating point (Ne, Te) of the first embodiment will be described.
FIG. 5 is a control block diagram for determining the engine operating point in the integrated controller 6 of the first embodiment.

The target drive power calculation unit (target drive power calculation means) 31 calculates a target drive power according to the accelerator opening APO and the vehicle speed VSP by searching a predetermined map from the accelerator opening APO and the vehicle speed VSP. .
The basic charge / discharge power calculation unit 32 outputs a basic charge / discharge power P0 corresponding to the battery SOC by searching a predetermined table from the battery SOC. The basic charging / discharging power P0 has a characteristic that the lower the battery SOC, the larger the charging side, and the higher the battery SOC, the larger the discharging side.

The shift candidate calculation unit 33 includes n small calculation units 34 corresponding to n target transmission ratio candidates that minimize the electric loss of the driving force combining transmission TM, and a basic calculation unit 35.
Each small computing unit 34 has a required charge / discharge power computing unit 34a and a system efficiency computing unit 34b.
The necessary charge / discharge power calculation unit 34a obtains a corresponding target gear ratio candidate (target gear ratio 1 to target gear ratio n) based on the target drive power output from the target drive power calculation unit 31 and the vehicle speed VSP. The required charge / discharge power Pn of the battery 4 is calculated.

In the system efficiency calculation unit 34b, based on the target drive power output from the target drive power calculation unit 31, the required charge / discharge power Pn output from the required charge / discharge power calculation unit 34a, and the vehicle speed VSP, The operation and efficiency of the first motor generator MG1 and the second motor generator MG2 are predicted, and the system efficiency En is output from each efficiency with reference to the following equation.
System efficiency En = Engine efficiency x 1st motor generator efficiency x 2nd motor generator efficiency x Battery efficiency

  The basic calculation unit 35 includes a basic system efficiency calculation unit 35b. In the basic system efficiency calculation unit 35b, the target drive power output from the target drive power calculation unit 31 and the basic charge / discharge power calculation unit 32 are output. Based on the basic charge / discharge power P0 and the vehicle speed VSP, the basic system efficiency E0 corresponding to the battery SOC is output.

  The charge / discharge power determination unit 36 employs the charge / discharge power Px that has the highest system efficiency among the necessary charge / discharge powers P1 to Pn output from each of the necessary charge / discharge power calculation units 34a. At this time, charging / discharging power exceeding the maximum charging / discharging power | Pmax |, which is an allowable maximum value of charging / discharging power, is not adopted. When the battery SOC is out of the predetermined range, the basic charge / discharge power P0 corresponding to the battery SOC is employed as the charge / discharge power Px in order to prevent overcharging / discharging of the battery 4.

The basic charge / discharge power calculation unit 32, the shift candidate calculation unit 33, and the charge / discharge power determination unit 36 constitute charge / discharge power calculation means of the first embodiment.
The adder 37 adds the target drive power output from the target drive power calculator 31 and the charge / discharge power Px output from the charge / discharge power determination unit 36 to calculate the engine required power.

  The engine operation / stop determination unit 38 determines whether to operate or stop the engine E based on the engine required power. That is, when the engine required power exceeds the activation determination threshold value α, it is determined that the engine E is operated. On the other hand, when the engine required power is smaller than the stop determination threshold β, it is determined that the engine E is stopped. Here, the start determination threshold value α and the stop determination threshold value β are values determined by requests such as fuel consumption and drivability. The engine operation / stop determination unit 38 outputs an engine ON / OFF signal according to the determination result.

The engine speed calculation unit 39 calculates an engine speed for obtaining the engine required power by searching a predetermined map from the engine required power.
The operating point determining unit 40 determines an engine operating point (Ne, Te) based on the engine required power output from the adding unit 37 and the engine speed output from the engine speed calculating unit 39, and the engine A control command corresponding to the operating point (Ne, Te) is output to the engine controller 1. When an engine OFF signal is output from the engine operation / stop determination unit 38, the operating point determination unit 40 outputs a fuel cut signal to the engine controller 1.

  The integrated controller 6 is configured such that the motor operating point (N1, T1) of the first motor generator MG1 and the motor operating point (N2, T2) of the second motor generator MG2 that can obtain the gear ratio and the engine operating point (Ne, Te). ) And control commands corresponding to these motor operating points (N1, T1) and (N2, T2) are output to the motor controller 2.

Next, the operation will be described.
As in the drive system shown in FIG. 1, in a drive system having two motor generators MG1 and MG2 and one or more planetary gears as a power distribution function, , Part of the output is also referred to as power.) A part of the planetary gear (Ravigno type planetary gear train PGR) is distributed to one of the motor generators MG1 and MG2, and the electric power converted by the regenerative operation of the one motor generator is The power is supplied to the other motor generator via the battery 4, and the power by the power running operation of the motor generator is transmitted to the output gear OG.

  At this time, the ratio at which the engine power is electrically converted, that is, the electrical circulation ratio, depends on the ratio between the input rotation speed and the output rotation speed of the driving force synthesis transmission TM, that is, the gear ratio, so the driving force depends on the gear ratio. The efficiency of the composite transmission TM changes.

  FIG. 6 is a diagram showing the relationship between the transmission ratio and the electrical circulation ratio of the driving force synthesis transmission TM of the first embodiment, and shows a curve indicating the characteristics of MG1 power / engine power [%] and MG2 power / engine power. The curve indicating the characteristics of [%] has a plurality of antinodes and nodes, and shows a characteristic that vibrates between the engine power release side and the engine power absorption side according to the speed change ratio, with respect to the horizontal axis (speed change ratio). It becomes a substantially contrasting shape. The number of nodes and antinodes varies depending on the structure of the driving force synthesizing transmission TM (number of planetary gears, etc.). In FIG. 6, the electric loss of the driving force combining transmission TM increases as the width (distance) of both curves at a certain gear ratio increases.

  Here, when the gear ratio is varied by the vehicle speed VSP, as shown in FIG. 7, a desired engine operation line (engine best fuel consumption operation line) that optimizes the fuel efficiency of the engine E is set. However, since the electric circulation ratio is increased by the vehicle speed VSP, the system efficiency of the entire vehicle is deteriorated.

  On the other hand, in the integrated controller 6 of the first embodiment, necessary charge / discharge powers for obtaining a plurality of transmission gear ratios (nodes a, b, c) in FIG. Of these, the required charge / discharge power with the highest system efficiency is used as the charge / discharge power, and the engine E and the motor generators MG1, MG2 are controlled to achieve this charge / discharge power.

  That is, the engine operating point is set so that the gear ratio is set so that the electric loss is minimized and the system efficiency of the entire vehicle is the highest, and the charge / discharge power of the battery 4 necessary to obtain the gear ratio is obtained. Since the motor operating point is determined, the system efficiency of the entire vehicle can be improved.

The effects of the engine operating point control device for the hybrid vehicle of the first embodiment are listed below.
(1) Control of a hybrid vehicle having a driving force synthesizing transmission TM having a Ravigneaux type planetary gear train PGR in which the engine E, the first motor generator MG1, the second motor generator MG2 and the output gear OG are respectively connected to rotating elements. In the apparatus, when the second motor generator MG2 or the first motor generator MG1 is driven by the battery 4 that exchanges power with the first and second motor generators, and the electric power generated by the first motor generator MG1 or the second motor generator MG2. Charge / discharge power calculation means (basic charge / discharge power calculation unit 32, shift candidate calculation unit 33 and charge / discharge) for calculating the charge / discharge power of the battery 4 to obtain the gear ratio of the driving force synthesizing transmission TM that minimizes the electric loss occurring The power determination unit 36) and the engine E and the first and second motor generators MG1 and MG2 are controlled so as to obtain charge / discharge power. And an integrated controller 6. Thereby, charging / discharging of the battery is performed so that the electric loss is minimized, so that the electric circulation ratio can be suppressed and fuel consumption can be improved.

  (2) The charge / discharge power calculation means calculates the charge / discharge power to obtain the gear ratio with the highest system efficiency of the entire vehicle including the engine efficiency, so that the engine fuel efficiency, motor generator power running efficiency and regenerative efficiency, battery charge / discharge It is possible to improve the system efficiency of the entire vehicle considering the discharge efficiency and the like.

  (3) A target drive power calculation unit 31 that calculates a target drive power corresponding to the accelerator opening APO is provided, and the integrated controller 6 has an engine power that is the sum of the charge / discharge power and the target drive power. Control E. As a result, it is possible to minimize the electric loss while achieving the required driving power of the driver.

  (4) When the battery SOC is out of the predetermined range, the charge / discharge power calculation means sets the charge / discharge power to a value corresponding to the battery SOC, so that overdischarge and overcharge of the battery 4 can be prevented. Improvements can be made.

(Other examples)
As mentioned above, although the control apparatus of the hybrid vehicle of this invention was demonstrated based on the Example, about a specific structure, it is not restricted to these Examples, The invention which concerns on each claim of a claim Design changes and additions are allowed without departing from the gist.

  In the first embodiment, the drive system configuration including the differential gear transmission having the Ravigneaux type planetary gear train has been described. However, the present invention transmits power to the engine, the first motor generator, the second motor generator, and the drive wheels. The output member to be applied can be applied to a drive system configuration provided with a differential gear transmission having a planetary gear train connected to each rotating element, and the same effects as those of the first embodiment can be obtained.

E engine
MG1 1st motor generator
MG2 Second motor generator
OG output gear (output member)
TM Driving force transmission (differential gear transmission)
PGR Ravigneaux type planetary gear train (planetary gear train)
EC engine clutch
LB Low brake 1 Engine controller 2 Motor controller 3 Inverter 4 Battery 5 Hydraulic control device 6 Integrated controller (control means)
7 Accelerator opening sensor 8 Vehicle speed sensor 9 Engine rotation speed sensor 10 First motor generator rotation speed sensor 11 Second motor generator rotation speed sensor 12 Second ring gear rotation speed sensor 31 Target drive power calculation section (target drive power calculation means)
32 Basic charge / discharge power calculation unit (charge / discharge power calculation means)
33 Shift candidate calculation unit (charge / discharge power calculation means)
34 Small calculation unit 34a Required charge / discharge power calculation unit 34b System efficiency calculation unit 35 Basic calculation unit 35b Basic system efficiency calculation unit 36 Charge / discharge power determination unit (charge / discharge power calculation means)
37 Adder 38 Engine operation / stop determination unit 39 Engine speed calculator 40 Operating point determination unit

Claims (4)

In a hybrid vehicle control device including a differential gear transmission having a planetary gear train in which an output member for transmitting power to an engine, a first motor generator, a second motor generator, and a driving wheel is connected to a rotating element,
A battery that exchanges power with both motor generators;
Charge / discharge power calculation for calculating the charge / discharge power of the battery to obtain the gear ratio of the differential gear transmission that minimizes the electric loss that occurs when the second motor generator is driven by the generated power of the first motor generator. Means,
Control means for controlling the engine and both motor generators to achieve the charge / discharge power;
A control apparatus for a hybrid vehicle, comprising: In the hybrid vehicle control device according to claim 1,
The control apparatus for a hybrid vehicle, wherein the charge / discharge power calculation means calculates charge / discharge power for obtaining a gear ratio with the highest system efficiency of the entire vehicle including engine efficiency. In the hybrid vehicle control device according to claim 1 or 2,
Provided with a target drive power calculating means for calculating a target drive power according to the accelerator opening,
The control device of the hybrid vehicle, wherein the control means controls the engine so as to obtain an engine required power that is a sum of the charge / discharge power and the target drive power. In the hybrid vehicle control device according to claim 1 or 2,
The control device for a hybrid vehicle, wherein the charge / discharge power calculation means sets the charge / discharge power to a value corresponding to the battery SOC when the battery SOC is out of a predetermined range.

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