JP2008150023A - Powertrain control method for hybrid vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for controlling the power train of a hybrid vehicle that improves fuel economy by driving the vehicle efficiently. <P>SOLUTION: The method for controlling the power train of the hybrid vehicle which comprises an engine, a battery, a first motor generator, a second motor generator, a planetary gear mechanism, and a controller controlling them includes a step for setting candidates for a driving condition of the power train on a plurality of lattice points within a drivable range shown as a function of engine torque and engine speed, and calculating the system efficiency of the power train while using each of the lattice points as a driving point, a step for selecting the driving point at which maximum efficiency is calculated among system efficiencies calculated for the driving points corresponding to the plurality of lattice points, and a step for controlling the engine, the first motor generator, and the second motor generator so that a driving condition satisfies the driving point selected. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a powertrain control method for a hybrid vehicle. More specifically, the present invention relates to an engine in a hybrid vehicle that uses a motor generator that is operated by an electric force with an engine of an internal combustion engine or that generates electric power by driving an engine or by a vehicle deceleration force. The present invention relates to a method for controlling a motor generator. The power train is a power generation engine including an engine, a battery, a motor generator, and a planetary gear mechanism.

Hybrid vehicles can be expected to significantly improve fuel efficiency compared to vehicles equipped with only an engine.
The motor has excellent torque characteristics compared to the engine in the low rotation speed region, and the engine has superior torque characteristics in the relatively medium and high speed regions compared to the motor. The fuel efficiency can be improved by efficiently controlling the vehicle according to the traveling state.

In general, in the control of the power train of a hybrid vehicle, the required torque is determined from the vehicle speed and the accelerator opening, and the required power is determined from the required torque and the vehicle speed.
Since power is the product of the number of revolutions and torque, there are multiple possible operating conditions, such as a point with a large number of revolutions and a small torque, or vice versa, to obtain this required power from the engine. . However, in order to obtain the same power, there are a point with high efficiency and a point with low efficiency from the viewpoint of engine efficiency, so it is desirable to select the point with the highest efficiency. This is because the higher the efficiency, the less energy loss and the better fuel efficiency.

The engine efficiency can be exemplified by a graph in which the engine torque is plotted on the vertical axis, the engine speed is plotted on the horizontal axis, and the torque limit is plotted on a curve in which an isoefficiency curve such as a contour line is drawn. The limit of torque corresponds to the torque when the accelerator is stepped on at the maximum number of revolutions. Further, the region with the highest engine efficiency (top of the mountain) is at a place where the rotational speed is relatively high and the torque is large.
For example, in the vicinity of 3000 to 4000 RPM, the torque is located immediately below the torque limit point. And it shows that engine efficiency becomes low every time it crosses an iso-efficiency curve from the region where engine efficiency is the highest.

The control of the power train in the conventional hybrid vehicle is performed based on the engine efficiency as described above, and is not controlled based on the efficiency considering the entire power train of the hybrid vehicle.
Extra power is generated in the operating state selected by the efficiency of the engine. This extra power is converted into electric power, stored in the battery, and used again to drive the motor. However, even if it is extra power, there is energy loss in the process of conversion or accumulation into electric power and re-conversion to power, so that the efficiency at the time of such reuse decreases.

For example, it is assumed that the operating state in which the engine efficiency α is high and the engine output 3Gkw is output is selected. Here, assuming that 3 GkW is distributed to the power of the wheel and not distributed to the battery, the system efficiency S with 3 GkW as the input amount in the denominator and α × 3 GkW as the output amount in the numerator is equal to the engine efficiency α. equal.
Since 1GkW is enough for the power of the wheel, assuming that 2GkW is distributed to the battery, it combines the loss when storing energy in the battery, the charge / discharge efficiency of the battery, and the loss when using it after discharging from the battery Is approximately 50%, and S is α × (G + 2G × 0.5) / 3G. If G is eliminated from the numerator and denominator, S = (2/3) × α. That is, the efficiency drops to about 2/3.

Here, it is assumed that a high value of the engine efficiency α is a, and an output satisfying the power of the wheels can be output with an efficiency b lower than the efficiency a. In this case, if b is larger than (2/3) × a, the engine efficiency is a> b, but in terms of system efficiency S, it can be said that it is more efficient to operate the engine with b. Thus, the control determined only by the engine efficiency may reduce the efficiency of the entire system.
JP 2006-076567 A

  An object of the present invention is to enable control of a power train in consideration of the efficiency of the entire power train system of the hybrid vehicle, not only considering the efficiency of the engine when controlling the power train of the hybrid vehicle. To provide a powertrain control method for a hybrid vehicle that can improve fuel efficiency by more efficient vehicle operation and reduce or eliminate vibrations and noise generated in the powertrain. is there.

  In order to achieve the above object, a powertrain control method for a hybrid vehicle according to the present invention includes a power for a hybrid vehicle comprising an engine, a battery, a first motor generator, a second motor generator, a planetary gear mechanism, and a control device for controlling them. In the method for controlling the train, the operation state candidates to be taken by the powertrain are taken as a plurality of grid points in the operable region indicated by a function of the engine torque and the engine speed, and the grid points are used as the respective operation points. Calculating the system efficiency of the powertrain, selecting an operating point at which maximum efficiency is calculated among the system efficiencies calculated for each operating point corresponding to the plurality of grid points, and the selection The engine and the first motor so that the operation state of the selected operation point is achieved. And controlling Nereta and second motor-generator, characterized in that it comprises a.

  The plurality of grid points are selected by dividing the number of rotations between idling rotation and maximum engine rotation and between 0 and the maximum torque in several places.

  The rotation speed region is divided into several points to several tens of points at equal intervals, and the torque region is divided into several points at equal intervals, and the intersections thereof are selected as the plurality of grid points.

  In addition, in order to calculate the system efficiency at each of a plurality of operating points, and to select the operating point at which the maximum efficiency is calculated among them, the operating points are stored in an array, and the array of each operating point is the operating point. The system efficiency and the multiplex arrangement adapted to indicate whether or not the operating point is within the output limit range of the first motor generator, the second motor generator, and the battery.

  In the calculation of the system efficiency, a calculation result is recorded in advance in the control device, and the calculation result is used.

  The operating point is selected within the output limits of the first motor generator and the second motor generator and the engine, and within the output limit range of charge and discharge of the battery.

  The present invention also relates to a powertrain control method for a hybrid vehicle including at least one engine, a motor generator, and a battery, and a drivable region indicating a candidate of an operating state that should have the powertrain as a function of engine torque and engine speed. Taking a plurality of grid points within the system, calculating the system efficiency of the powertrain using each grid point as each operation point, selecting an operation point at which the highest efficiency is calculated, and selecting the selected operation If the difference between the efficiency of the powertrain system at the point and the efficiency of the powertrain system depending on the current operating state is higher than the expected value, the engine and the motor generator are controlled so that the operating state of the selected operating point is achieved. And the step of performing.

  In calculating the system efficiency of the powertrain, a calculation result is recorded in advance in a control device, and the operation point is selected using the calculation result.

  The candidate for the operation state is selected within the operation limit range of a motor generator, an engine, and a battery constituting the power train.

  The engine and the motor generator are controlled so as to obtain an operation state in which the maximum efficiency is obtained when the motor generator, the engine, and the battery constituting the power train are close to the operation limit range.

  When the amount of operation of the driver, the load speed and load resistance of the power generation engine have changed to a predetermined value or more than when the current operating state is determined, the motor is set so as to obtain the maximum operating efficiency. The generator and the engine are controlled.

According to the present invention, when controlling the powertrain of the hybrid vehicle, the powertrain is controlled in consideration of the efficiency of the entire powertrain system of the hybrid vehicle, not only the efficiency of the engine. The fuel efficiency can be improved by more efficient vehicle operation.
Further, according to the present invention, even when a certain operating point (current operating point) is selected and operated, even if the maximum efficiency point is different in the operable range, the current value exceeds a predetermined value. When the efficiency is not higher than the driving point, by not changing the driving point, the frequency of changing the driving point is reduced as a result, and vibration and noise can be eliminated.

  Hereinafter, a configuration of a power train and a control method thereof in a hybrid vehicle according to the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a configuration diagram of a powertrain of a hybrid vehicle according to the present invention.
The power train 100 includes an engine 1, a planetary gear mechanism 15 including a carrier 2, a planetary gear 3, a sun gear 4, and a ring gear 5, a first motor generator 6 and a second motor generator 7 that serve both as an electric motor and a generator, The inverters 8 and 9, the battery 10, the differential gear 12, and the axle 14 are controlled by the control device 16, and the generated power is transmitted to the tire 13.

The output of the engine 1 is connected to the carrier 2 of the planetary gear mechanism 15 via a crankshaft. The inverters 8 and 9 are devices that convert the direct current of the battery 10 into the alternating current of the first motor generator 6 and the second motor generator 7.
The first motor generator 6 connected to the sun gear 5 is shown as MG1, and the second motor generator 7 connected to the ring gear 5 is shown as MG2. The shaft of the ring gear 5 can transmit power to the axle 14 via the chain 11.

FIG. 2 is a graph showing the relationship between the operating point and efficiency of the engine used in the present invention. The vertical axis represents the engine torque, and the horizontal axis represents the engine speed. The curve plotted at the top represents the maximum engine torque 20 with respect to the rotational speed of the engine 1.
The engine 1 is operated in a region below the maximum engine torque 20. The equiefficiency lines 31, 32, and 33 with the same engine efficiency indicate that the efficiency decreases as going outward, and the inside of the region indicated by the isoefficiency line 31 has the highest operating efficiency as the engine.

The operation point 30 is an intersection divided in a grid pattern. The engine 1 can be operated in a plurality of operation states determined from the operation point 30. The limit low speed 21 of the engine 1 is located on the left side of the graph of FIG. It is desirable to operate at an engine speed greater than the limit low speed speed 21.
The control device 16 calculates the system efficiency of the powertrain at the vehicle speed and load at that time for the operation point 30 that is a combination of the engine speed and the engine torque at a constant cycle, and the operation with the highest system efficiency is performed. Identify points. Then, the engine 1, the first motor generator 6, and the second motor generator 7 are controlled so that the engine is in the operating state at the operating point. The control of the first motor generator 6 and the second motor generator 7 may include inverters 8 and 9. Further, the motor generator may be either AC or DC.

ここで、ＭＧ１、ＭＧ２は共に発電機として動作し、その出力がバッテリに蓄えられる場合である。Ｗｅ、Ｗｍｇ１、Ｗｍｇ２は、それぞれ遊星歯車機構１５の出力軸、ＭＧ１、ＭＧ２に分配されるエンジンの電力を単位とする出力である。αは運転ポイントにおけるエンジン効率で、βはＭＧ１、ＭＧ２のエネルギー変換効率で、γはバッテリの効率を表す。Ｗｍｇ１またはＷｍｇ２にβが２回乗じられているのは、エンジンの出力が最終的な動力になるには、ＭＧ１またはＭＧ２の出力はバッテリへの取り込み時と取り出し時の２回通過するからである。 Next, the hybrid system efficiency S is defined as follows.

Here, MG1 and MG2 both operate as generators and the output is stored in the battery. We, Wmg1, and Wmg2 are outputs in units of electric power of the engine distributed to the output shaft of the planetary gear mechanism 15, MG1, and MG2, respectively. α is the engine efficiency at the operating point, β is the energy conversion efficiency of MG1 and MG2, and γ represents the efficiency of the battery. The reason why β is multiplied twice by Wmg1 or Wmg2 is that the output of MG1 or MG2 passes twice at the time of taking in the battery and at the time of taking it out for the engine output to become the final power.

  Also, for example, when MG2 is operated as an electric motor and QkW power is output to the shaft on which the chain 11 is applied, the item [Wmg2 × β × β × γ] has an output that has passed through MG2 and MG1. Assuming QkW, it is calculated by [Q × (1 / β) × (1 / β) × β × β]. At this time, if the MG1 is operated as a generator, the item [Wmg1 × β × β × γ] supplies QkW to the MG2, so the energy obtained by subtracting that amount goes to the battery 10, and that energy is used separately. Is calculated using [{Wmg1-Q × (1 / β) × (1 / β)} × β × β × γ].

FIG. 3 is a graph showing the relationship between the operating point of the engine used in the present invention and the efficiency, and shows the operable region. The region shown in gray in FIG. 3 is the operable region (within the output limit). In other words, the left side of this region is partitioned by the limit low speed 21 of the engine 1. That is, it is desirable that the engine speed be larger than this.
The lower side of this region is partitioned by the minimum torque 23 of MG2. The motor generator 7 operates as an electric motor, and a certain torque or more is required to transmit power to the axle, and the engine torque of the engine 1 is preferably larger than this.
The upper side of this region is partitioned by the torque characteristic value 22 of MG1. When the motor generator 6 MG1 operates as a generator, the torque of the MG1 gradually decreases when the crankshaft of the engine 1 rotates at a high speed. Reference numeral 24 represents engine torque requested by the driver. Further, the battery charge limit 25 and the discharge limit 26 are indicated by dotted lines.

In FIG. 3, when the operable region is not grasped, an operation point 30a with high operation efficiency is selected. When the operable region is not taken into account, after obtaining the operation point 30a, when the torque is not so much required, the torque is simply reduced and the operation point 30b is selected. However, when the operable region is known, all the operation points 30b and 30c are considered.
Here, when the hybrid stem efficiency is calculated and compared at each point of 30b and 30c according to Equation 1, the operating point 30c is higher than the operating point 30b, and thus the operating point 30c is selected. The fact that the hybrid stem efficiency of the operating point 30c is higher than that of the operating point 30b indicates that the engine efficiency α is high, and MG1 and MG2 are constant at the two operating points 30b and 30c. By doing so, it can be easily confirmed by Equation 1.

4 and 5 are energy balance diagrams of the powertrain. When the driving point is evaluated based on the hybrid system efficiency, it is possible to perform driving with better fuel efficiency than the driving state determined only by the efficiency of the engine 1. As shown in FIG. 3, in general, it is desirable that the engine be operated in a region having a large engine speed and a large engine torque.
FIG. 4 is an energy balance diagram of a powertrain in an operating state selected using only engine efficiency. As shown in FIG. 4, here, the highest efficiency point of the engine 1 was selected based only on the engine efficiency, and the operation point (p1) at which an output of 150 kw was obtained was selected. Here, it is assumed that the engine efficiency (ratio of shaft output to fuel heat value) α is 30%. At this time, the energy transmitted to the MG 1 via the planetary gear mechanism 15 is set to 1/3 of the output of the engine 1, 1/3 to the MG 2, and 1/3 to the axle 14, and 50 kW is distributed respectively. .

  The efficiency β as the generator and motor of MG1 and MG2 is 70%. In that case, the outputs of MG1 and MG2 are each 35 kW (= 50 kW × 0.7). In this case, since the battery 10 is charged by two of MG1 and MG2, the supplied power is 70 kW. The efficiency γ of the battery 10 is 90%. The electric power stored in the battery 10 is consumed when the first motor generator 6 and the second motor generator 7 are used as electric motors, and is converted into mechanical force again with an efficiency β of 70%. In this case, the battery 10 can be regarded as having produced mechanical power of 44.1 kW (= 70 kW × 0.9 × 0.7).

The operating point p1 is selected only from the engine efficiency β. For comparison, when the system efficiency S is calculated by Equation 1, S (p1) = 18.82% is obtained. Here, the engine output of 150 kW is distributed to We, Wmg1, and Wmg2 by 50 kW, α is 30%, β is 70%, and γ is 90%.
In FIG. 4, if MG2 is controlled as an electric motor, the output to axle 14 will be higher than the required value. Therefore, MG2 and inverter 9 are controlled so as to be a generator. In this way, when only the engine efficiency α is considered, there is a case where it is far from the required axle output value, and the difference is stored in the battery and used separately. However, the utilization efficiency hs is as low as 49% (= 70% × 70%) because it passes through the motor generator twice. In the selection based only on the engine efficiency α, for example, an operating point where the engine output is as low as 63 kW and the engine efficiency α is as low as 25% is not selected.

  FIG. 5 is an energy balance diagram of the powertrain in the operating state selected using the hybrid system efficiency S according to the present invention. An energy balance diagram of the powertrain at an operating point (p2) where the engine output is as low as 63 kW and the engine efficiency α is 25% is shown. At this operation point (p2), MG1 is controlled as a generator, and MG2 is controlled as an electric motor. In that case, 21 kW (= 63 kW × 1/3) of the output 63 kW of the engine 1 is distributed to MG1, and the remaining 42 kW (= 63 kW × 2/3) is distributed to the output of the ring gear 5 of the planetary gear mechanism 15. And When MG2 is operated as an electric motor, an output of 8 kW is obtained. In that case, the axle 14 can obtain 50 kW (= 42 kW + 8 kW), which is the same as in FIG.

Here, the output of MG1 is 14.7 kW (= 21 kW × 0.7) multiplied by 70%, which is the efficiency β of MG1. Note that 11.43 kW (= 8 kW / 0.7) is required to move the MG2 as an electric motor, and if this is consumed from the output of the MG2, the battery 10 has 3.3 kW (= 14.7 kW-11). .43 kW) of charging power will be supplied. In this case, the system efficiency S is calculated as S = 20.66%.
Specifically, S (p2) = 1/100 × 0.25 × [42 kW + 8 kW × (1 / 0.7) × (1 / 0.7) × 0.7 × 0.7 + {21 kW−8 kW × ( 1 / 0.7) × (1 / 0.7)} × 0.7 × 0.7 × 0.9] / 63 kW.

In this way, despite the fact that the engine efficiency is not optimal, S (p1) <S (p2) is satisfied, so that the driving efficiency is improved. Since S (p1) is 18.82% and S (p2) is 20.66%, the efficiency is 9.78% (= (20.66-18.82) based on S (p1). ) /18.82×100%). That is, even if the powertrain components are the same, it is possible to expect an improvement in fuel consumption of about 10% by control.
In this embodiment, MG2 is used not as a generator but as a motor, and the efficiency is improved by suppressing the amount of charge to the battery. In addition, the efficiency can be improved by reducing the amount of power generation by lowering the operating speed of the MG1. If the power generation amount is suppressed too much, the engine will be used at a point where the engine efficiency is too bad, and the system efficiency will be reduced.

FIG. 6 is a control flowchart of the control device 16. The operation points as operation candidates are equally spaced on the plane of the engine speed and engine torque, 30 points at 200 rpm intervals from 500 rpm to 6000 rpm in the rotation speed direction, and 20 Nm from 0 Nm to 200 Nm in the torque direction. Take 10 points at intervals.
A 30 × 10 element candidate operation point information matrix OPM having information corresponding to each of the 30 candidate points × 10 candidate operation points is defined as follows.
The i-th element OPMij in the rotational speed direction and the j-th element in the torque direction are: OPMij = [OPMij1, OPMij2] = [efficiency at the ij point, whether the ij point is within the output limits of the MG1, MG2, and battery] did.

As shown in FIG. 6, it is determined in S11 whether or not the operating point is within the drivable range. If it is within the drivable range, the hybrid system efficiency is calculated in S13, and the efficiency higher than the efficiency calculated previously in S14. If it is determined, the operation point is stored in OPMIJ1 as the highest efficiency so far in S15.
Therefore, all the operation points are confirmed, and the one stored in OPMIJ is the most efficient operation point. As described above, as shown in FIG. 6, the method of searching for the highest system efficiency among all the operating points is repeated by repeating S11 to S15 while increasing j to 10 by S16 and S22, and S17 and S17. The method of repeating S11 to S15 while increasing i to 30 by S21 was used.

On the other hand, OPMij2 determines whether or not the operation point (i, j) to be currently calculated is within the output limits of the engine, MG1, MG2, and battery. In the other case, the array element is stored with a value of 0, and this is determined in S14.
As described above, when the operation point having the highest system efficiency among all the operation points is found, the control device 16 operates the engine 1, the first motor generator 6 and the second motor generator 7 at the selected operation point. By performing the control as described above, the power train of the hybrid vehicle is driven in a more efficient driving state.

The control device 16 is constituted by a microprocessor having a ROM and a RAM, and for example, a control program stored in the ROM can be stored in the RAM and executed. The calculation result of the hybrid system efficiency at each operation point that takes time can be stored in the ROM in advance, and the processing speed can be increased.
On the other hand, when the powertrain is operated using the control method as described above and the operation point is determined by selecting the highest efficiency point, vibrations or abnormal noise due to frequent fluctuations in the rotational speed occur. There are things to do.
In other words, if the highest efficiency point indicates a point where the rotational speed has greatly deviated due to a slight change in operating conditions, vibration or noise may occur due to vibration between multiple points with different efficiency. is there.

When the above-mentioned vibration or abnormal noise is a concern, a powertrain control method for a hybrid vehicle according to the present invention presented as a solution to this will be described with reference to FIGS.
As shown in FIG. 7, in the present invention, the efficiency of each operation candidate point is calculated (S101), and if the operation point at which the maximum efficiency is obtained is selected (S102), the current operation point is the component operation of the powertrain. It is determined whether the limit is approached (S103).
For example, if the engine speed is lower than the engine speed at which engine output is disabled and deviates from a predetermined engine speed, it is determined that the engine is close.
Next, if the current operation point is close to the operation limit of each component of the powertrain, the efficiency of the current operation point is calculated (S104), and if not, the operation state is changed to the maximum efficiency point (S105). .

Next, when the efficiency of the current operating point is calculated, the difference between the maximum efficiency point efficiency in the operating state and the operating efficiency in the current operating state is determined from a predetermined value by the estimation function of the maximum efficiency operating state of the power train. If it is higher (S016), the current driving point is estimated (S107).
That is, the motor generator and the engine are controlled so as to obtain an operation state in which the highest efficiency is obtained.
On the other hand, the highest efficiency point is selected according to the rank. That is, as shown in FIG. 10, when there are a plurality of driving regions having high efficiency apart, a small change in the vehicle speed, the torque required by the driver, or the rotation speed of the engine or motor generator is detected, and the current driving is detected. If a point that is more efficient than a point appears, that point is selected immediately.

Therefore, the operating point is frequently changed, and the engine speed and torque fluctuate to generate vibration and noise.
Therefore, if the control method of the present invention is applied, the current operating point is maintained with a slight difference in efficiency, and the frequency of changing the operating point is reduced. Therefore, the occurrence of vibration and abnormal noise can be reduced.
In addition, if a certain component is close to the operation limit, generally, the operation efficiency of the component is significantly reduced. Therefore, when the control method of the present invention is applied, the current operating point is mostly not the highest efficiency point, and since the frequency of reaching the operating limit is not high, it is exceptional when approaching the operating limit. If the operating point is changed to the highest efficiency point, the operating efficiency of the engine can be improved without deteriorating vibration and noise.
In addition, when there is a change in the driver's operation and load, the sensitivity of the sense of discomfort to sound or vibration is low. It can be expected to improve the driving efficiency without generating it.

  The powertrain control method according to the present invention is suitable for a hybrid vehicle in which further improvement in fuel consumption is desired.

It is a block diagram of the powertrain of the hybrid vehicle by this invention. It is a graph which shows the relationship between the operating point of the engine used by this invention, and efficiency. It is a graph which shows a driving | operation possible area | region in the graph showing the relationship between the operating point of an engine used by this invention, and efficiency. FIG. 4 is an energy balance diagram of a powertrain in an operating state selected using only engine efficiency. It is an energy balance figure of the powertrain in the operation state selected using hybrid system efficiency S. It is a control flowchart of a control apparatus. 3 is a flowchart illustrating a powertrain control method for a hybrid vehicle according to the present invention. It is a graph which shows the case where the efficiency of a present driving point and the highest efficiency point approximates, when not changing an operating point. When changing an operation point, it is a graph which shows the case where the efficiency difference of a present operation point and the highest efficiency point is large. It is a graph which shows driving | operation efficiency when the driving | operation area | region which has high efficiency exists apart.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Engine 2 Carrier 3 Planetary gear 4 Sun gear 5 Ring gear 6 1st motor generator 7 2nd motor generator 8, 9 Inverter 10 Battery 11 Chain 12 Differential gear 13 Tire 14 Axle 15 Planetary gear mechanism 16 Control apparatus 100 Power train

Claims (11)

In a method for controlling a power train of a hybrid vehicle comprising an engine, a battery, a first motor generator, a second motor generator, a planetary gear mechanism, and a control device for controlling them,
The driving state candidates to be taken by the power train are taken as a plurality of grid points within the operable range indicated by a function of the engine torque and the engine speed, and the system efficiency of the power train is determined by using the grid points as the respective operating points. The stage of calculating,
Selecting an operating point at which the highest efficiency is calculated among the system efficiencies calculated for each operating point corresponding to the plurality of grid points;
Controlling the engine, the first motor generator and the second motor generator so as to be in the operating state of the selected operating point;
A powertrain control method for a hybrid vehicle, comprising:   2. The hybrid according to claim 1, wherein the plurality of grid points are selected by dividing the number of rotations between idling rotation and engine maximum rotation and between torque 0 and maximum torque in several places. A vehicle powertrain control method.   3. The rotation speed region is divided into several points to several tens of points at equal intervals, the torque region is divided into several points at equal intervals, and the intersections thereof are selected as the plurality of grid points. Powertrain control method for hybrid vehicles. In order to calculate the system efficiency at multiple operating points, and select the operating point where the highest efficiency is calculated,
The operation points are stored in an array, and the array of each operation point indicates the system efficiency at that operation point and whether the operation point is within the output limits of the first motor generator, the second motor generator, and the battery. 4. The powertrain control method for a hybrid vehicle according to claim 3, wherein the power train control method is a multiple arrangement that indicates whether or not.   2. The hybrid vehicle powertrain control method according to claim 1, wherein the calculation of the system efficiency is performed by previously recording a calculation result in the control device and using the calculation result.   2. The hybrid vehicle according to claim 1, wherein the operation point is selected within an output limit of the first motor generator and the second motor generator and the engine, and within an output limit range of charge and discharge of the battery. Powertrain control method. In a powertrain control method for a hybrid vehicle including at least one engine, a motor generator, and a battery,
The driving state candidates that should have the powertrain are taken as a plurality of grid points within the operable range indicated by a function of the engine torque and the engine speed, and the system efficiency of the powertrain is calculated using each grid point as each driving point. And selecting the operating point where the highest efficiency is calculated,
If the difference between the efficiency of the powertrain system at the selected operating point and the efficiency of the powertrain system according to the current operating state is higher than a predetermined value, the engine is set to the operating state at the selected operating point. And controlling the motor generator,
A powertrain control method for a hybrid vehicle, comprising:   The power efficiency of the hybrid vehicle according to claim 7, wherein the calculation of the system efficiency of the power train records a calculation result in a control device in advance and selects the driving point using the calculation result. Train control method.   8. The hybrid vehicle powertrain control method according to claim 7, wherein the driving state candidates are selected within a driving limit range of a motor generator, an engine, and a battery constituting the powertrain.   The engine and the motor generator are controlled so as to obtain an operation state in which the highest efficiency is obtained when the motor generator, the engine, and the battery constituting the power train are close to the operation limit range. A power train control method for a hybrid vehicle according to claim 9.   When the amount of operation of the driver, the load speed and load resistance of the power generation engine have changed to a predetermined value or more than when the current operating state is determined, the motor is set so as to obtain the maximum operating efficiency. 8. The method for controlling a powertrain of a hybrid vehicle according to claim 7, wherein the generator and the engine are controlled.

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