JP2021194984A - Hybrid vehicle control device - Google Patents

Abstract

To provide a hybrid vehicle control device capable of increasing fuel efficiency during power generation with an engine.SOLUTION: A hybrid vehicle control device comprises engine power generation implementation determination means (207) which determines whether or not to implement power generation with an engine when an SOC estimated value of a battery (106) is in a range between a predetermined value and an estimated lowest battery SOC, on the basis of a comparison between a fuel consumption rate assuming the implementation of the power generation with the engine using a motor generator (105) and a fuel consumption rate assuming that the power generation with the engine is not implemented. The hybrid vehicle control device is adapted to implement the power generation with the engine using the motor generator (105) when a determination result of the engine power generation implementation determination means (207) is affirmative.SELECTED DRAWING: Figure 2

Description

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

In recent years, hybrid vehicles that obtain power from a plurality of drive sources such as engines and motor generators have become widespread as vehicles that take energy saving and environment into consideration. In a hybrid vehicle, the state of charge (hereinafter abbreviated as "SOC"), which is the remaining electric capacity of the battery, is reduced in a relatively short period of time due to the use of a motor generator, auxiliary equipment, and the like. Therefore, in general, regenerative braking control that converts kinetic energy into electrical energy during deceleration and downhill is performed, or the generator is driven by the power of the engine during acceleration and steady running (hereinafter, "engine power generation"). By controlling (abbreviated as), the battery is supplied with power to be charged, and the SOC is restored.

Here, when the vehicle is driven by the engine alone or by the engine and the motor generator without the need for engine power generation, the engine is controlled at the driving point where the fuel consumption rate becomes small for the purpose of reducing fuel consumption. Is common. On the other hand, when engine power generation is required, the engine is required to have an output for generating the charging power to the battery after securing the vehicle driving force required for acceleration and steady driving. Therefore, the engine cannot be operated at an operating point where the fuel consumption rate is small (the operating point of the engine expressed by the engine torque and the engine rotation speed), and the fuel consumption may deteriorate. Therefore, from the viewpoint of improving fuel efficiency, it is important to control the battery at the operating point where the fuel consumption rate is as low as possible even when the battery is charged by engine power generation.

For example, in the conventional hybrid vehicle control device disclosed in Patent Document 1, stepless speed change is performed so that the operating point has a low fuel consumption rate while satisfying the required engine output when the battery is charged by engine power generation. The engine speed is controlled by changing the gear ratio of the machine, and the engine torque is controlled by fuel control to improve fuel efficiency during engine power generation.

Japanese Unexamined Patent Publication No. 2001-112115

In the technique disclosed in Patent Document 1, in order to control the engine speed so as to be an operating point where the fuel consumption rate is small, a configuration using a continuously variable transmission is required. Since the continuously variable transmission is configured to transmit power by a metal belt, it is said that the transmission efficiency is poor in the high speed region and the fuel consumption when driving the vehicle tends to deteriorate. Therefore, there are many vehicles equipped with a stepped transmission. Since the stepped transmission is a transmission mechanism in which the gear ratio is stepwise (discontinuous), the engine speed is such that the fuel consumption rate is small as in the conventional technique disclosed in Patent Document 1. It is difficult to control the driving point accurately. From the above, in a vehicle having a stepped transmission, it may not be possible to obtain the effect of improving fuel efficiency during engine power generation using the technique disclosed in Patent Document 1.

Here, as disclosed in Patent Document 1, the timing for performing engine power generation is generally set to be when the SOC of the battery falls below a predetermined value. This predetermined SOC value is the minimum amount of power to avoid risks such as battery damage, the power of auxiliary equipment such as air conditioners, and the margin provided as other power to be retained. It is a value that is preset in consideration of the whole such as the amount of electric power.

Since the amount of power required by the auxiliary machine depends on the degree to which the driver uses the auxiliary machine, a large margin as the amount of power for the auxiliary machine tends to be set from the viewpoint of battery protection. There is. Therefore, depending on the usage condition of the auxiliary equipment by the driver, engine power generation may be performed even though there is a margin more than necessary, and engine power generation is not always performed at an appropriate timing. Not at all. This is possible regardless of the mechanism of the transmission.

The present application discloses a technique for solving the above-mentioned problems, and an object of the present application is to provide a control device for a hybrid vehicle that realizes improvement in fuel efficiency during engine power generation.

The hybrid vehicle control device disclosed in the present application is
An engine that operates by burning fuel to generate power, a motor generator that can generate power by being driven by the power of the engine, a battery that charges the power generated by the motor generator, and the battery. A hybrid vehicle control device configured to control a hybrid vehicle equipped with at least one auxiliary device that is powered by and operates from.
A battery SOC estimated value calculation means for estimating the battery SOC, and a battery SOC estimated value calculation means.
A fuel consumption rate calculation means for calculating the fuel consumption rate at the operating point of the engine, and
Auxiliary power consumption calculation means for calculating the consumption of electricity used by the auxiliary machine, and
An SOC minimum remaining capacity calculation means that estimates the minimum SOC of the battery according to the consumption amount calculated by the auxiliary power consumption calculation means.
It is determined whether or not the SOC of the battery estimated by the battery SOC estimated value calculating means is between a preset value and the minimum SOC of the battery estimated by the SOC minimum remaining capacity calculating means. Engine power generation area determination means and
When the result of the determination by the engine power generation area determination means is affirmative, at least the fuel consumption rate of the engine when the engine power generation is assumed and the fuel consumption rate of the engine when the engine power generation is not performed are assumed. An engine power generation implementation determination means for determining whether or not to execute the engine power generation based on a comparison with the fuel consumption rate of the engine.
Equipped with
When the result of the determination of the engine power generation implementation determination means is affirmative, the engine power generation is configured to be executed.
It is characterized by that.

According to the hybrid vehicle control device disclosed in the present application, a hybrid vehicle control device that realizes improvement in fuel efficiency during engine power generation can be obtained.

It is a block diagram which shows the whole vehicle system including the control device of the hybrid vehicle by Embodiment 1 and Embodiment 2. It is a block diagram which shows the structure of the control device of the hybrid vehicle by Embodiment 1. FIG. There is a flowchart showing the operation of the control device of the hybrid vehicle according to the first embodiment. It is explanatory drawing which shows the example of the map for the correction coefficient α calculation in the control device of the hybrid vehicle by Embodiment 1 and Embodiment 2. It is explanatory drawing which shows the structure of the SOC minimum remaining capacity in the control device of the hybrid vehicle by Embodiment 1 and Embodiment 2. It is explanatory drawing which showed the example of the fuel consumption rate map in the control device of the hybrid vehicle by Embodiment 1 and Embodiment 2. It is explanatory drawing which shows the engine shaft torque when the engine power generation is assumed and the engine power generation is assumed. It is explanatory drawing which shows the fuel consumption rate map in the control device of the hybrid vehicle by the comparative example. It is a timing chart explaining an example of the operation of the control device of the hybrid vehicle by Embodiment 1. FIG. It is explanatory drawing which shows the operation of the control device of the hybrid vehicle by Embodiment 1 with the fuel consumption rate map. It is a timing chart explaining another example of the operation of the control device of the hybrid vehicle by Embodiment 1. FIG. It is a block diagram which shows the control device of the hybrid vehicle by Embodiment 2. FIG. It is a flowchart which shows the operation of the control device of the hybrid vehicle by Embodiment 2. FIG. It is explanatory drawing which shows the relationship between the auxiliary machine current consumption amount and auxiliary machine power suppression component torque in the control device of the hybrid vehicle according to Embodiment 2. FIG. It is a timing chart which shows the operation of the control device of the hybrid vehicle by Embodiment 2. It is explanatory drawing which shows the operation of the control device of the hybrid vehicle by Embodiment 2 with the fuel consumption rate map.

Hereinafter, each embodiment will be described with reference to the drawings, but the same or corresponding members and parts in each drawing will be described with the same reference numerals.

Embodiment 1.
Hereinafter, when the SOC of the battery is low, an SOC area is provided in which it is possible to select whether or not to perform engine power generation according to the use of auxiliary equipment and changes in the use thereof, and engine power generation is performed in that area. However, the first embodiment in which the engine power generation is performed only when the fuel consumption rate is estimated to be small will be described with reference to the drawings. FIG. 1 is a configuration diagram showing an entire vehicle system including a control device for a hybrid vehicle according to the first embodiment and the second embodiment described later.

As shown in FIG. 1, the vehicle system including the control device for the hybrid vehicle according to the first embodiment and the second embodiment described later includes an engine 101 operated by combustion of fuel, an electric motor, and a motor generator used as a generator (as shown in FIG. 1). Hereinafter, it is referred to as "MG") 105. The crank pulley 102 of the engine 101 and the pulley 103 of the MG 105 are connected via a belt 104. The power generated by the engine 101 and MG 105 is transmitted to the tire 111 connected to the drive shaft 110 via the transmission 108 and the differential gear 109.

The engine 101 is controlled by an engine control electronic control unit (hereinafter, abbreviated as "engine ECU") 112. The engine ECU 112 is composed of a microprocessor or the like, and performs fuel control of the engine 101 and the like. In the engine ECU 112, the cycle of the crank angle is detected by a rotation sensor (not shown) installed on the engine crank shaft, and the engine rotation speed Ne calculated from the detected cycle of the crank angle is used as a vehicle control electron. It is sent to the control unit (hereinafter, abbreviated as "vehicle ECU") 114.

The MG 105 is connected to the battery 106 via an inverter (not shown). The MG 105 generated electricity by either engine power generation driven by power transmitted from the engine 101 via a belt 104 to generate power, or regenerative braking power generation driven by kinetic energy during deceleration of the vehicle to generate power. Power is supplied to the battery 106. On the other hand, the MG 105 operates as an electric motor by the electric power of the battery 106, and power running operation for driving the vehicle is also performed.

The MG 105 is controlled by the MG control electronic control unit (hereinafter, abbreviated as “MG ECU”) 113. The MG ECU 113 is composed of a microprocessor or the like, and performs drive control, regenerative control, and the like of the MG 105.

The battery 106 is charged by the electric power generated by driving the MG 105 by the power of the engine 101 or the power transmitted from the drive shaft 110 at the time of deceleration of the vehicle, and discharges when the MG 105, the auxiliary machine 107, etc. need to be driven. The battery current sensor 118 connected to the battery 106 detects the current of the battery 106, and the detection signal is taken into the vehicle ECU 114. The current of this battery 106 is used to estimate the SOC. In the first embodiment, the current of the battery 106 is detected by the battery current sensor 118, but a detected value or an estimated value by a measuring method other than the current sensor may be used.

The auxiliary machine 107 is an electrical component other than the MG 105 that uses the electric power of the battery 106, and is, for example, an air conditioner. A current sensor (not shown) is connected to the auxiliary machine 107, and the current consumption of the auxiliary machine 107 detected by the current sensor is an electronic control unit for a vehicle body (hereinafter abbreviated as "ECU for a vehicle body") (FIG. A signal is taken into the vehicle ECU 114 via (not shown). In the first embodiment, the current consumption of the auxiliary machine 107 is detected by the current sensor, but the current consumption is measured by a measurement method other than the current sensor, such as a method of calculating from the current amount of the battery 106 and the current amount of the MG 105. You may do so.

The vehicle ECU 114 includes a CPU that performs arithmetic processing (not shown), a ROM that stores program data and fixed value data (not shown), and a RAM that updates and sequentially rewrites the stored data (not shown). ), And a microcomputer (not shown) having a backup RAM (not shown) that holds the stored data even when the power of the vehicle ECU 114 is turned off, and I / O that inputs and outputs various signals. It consists of an interface (not shown).

Various signals input to the vehicle ECU 114 include signals from the vehicle speed sensor 115, the accelerator position sensor 116, the brake stroke sensor 117, the battery current sensor 118, and the like, and among these signals, the vehicle speed from the vehicle speed sensor 115 is indicated. The signal, the signal indicating the accelerator opening degree from the accelerator position sensor 116, and the signal indicating the brake position from the brake stroke sensor 117 are used as signals for determining the operating state of the vehicle and the vehicle operation request of the driver.

Further, the signal indicating the battery current from the battery current sensor 118 is used for calculating the SOC estimated value SOCe of the battery 106, the power generation torque Teg, and the like. Further, the signal indicating the vehicle speed from the vehicle speed sensor 115 and the signal indicating the accelerator opening degree from the accelerator position sensor 116 are used for calculating the vehicle drive torque Teb. The generated torque Teg and the vehicle drive torque Teb are a part of the torque required for the engine 101, and are configured to send signals related to these to the engine ECU 112 to appropriately control the engine 101. ..

FIG. 2 is a block diagram showing a configuration of a control device for a hybrid vehicle according to the first embodiment, and is stored in the vehicle ECU 114. In FIG. 2, the control device 1000 stored in the vehicle ECU 114 is configured to control the power generation of the MG 105 by the engine 101 at an appropriate timing, and the auxiliary power consumption calculation means 201 and the auxiliary machine current consumption amount. The correction coefficient calculation means 202, the SOC minimum remaining capacity calculation means 203, the SOC estimated value calculation means 204, the engine power generation area determination means 205, the fuel consumption rate calculation means 206, the engine power generation implementation determination means 207, and the engine power generation implementation means 208 are provided. , The programs constituting these means and the fixed value data are stored in the above-mentioned ROM. Further, the initial battery SOC value KSOCi and the auxiliary current consumption amount Hw immediately before the ignition switch is turned off are stored in the backup RAM as the battery SOC value immediately before the ignition switch is turned off.

The auxiliary power consumption calculation means 201 uses the current consumption Iux [A] as the amount of electricity used by the auxiliary machine 107 taken into the vehicle ECU 114 via the vehicle body ECU (not shown above), and the unit time is used. Auxiliary current consumption per unit Hw [Ah] is calculated. A specific calculation method will be described with reference to the flow chart of FIG. 3 described later.

The auxiliary machine current consumption correction coefficient calculation means 202 calculates the auxiliary machine current consumption amount correction coefficient α by using the auxiliary machine current consumption amount Hw [Ah] calculated by the auxiliary machine power consumption calculation means 201. A specific calculation method will be described with reference to the flow chart of FIG. 3 described later.

The SOC minimum remaining capacity calculation means 203 first has the auxiliary machine current consumption amount Hw [Ah] calculated by the auxiliary machine power consumption calculation means 201 and the auxiliary machine current consumption amount calculated by the auxiliary machine current consumption correction coefficient calculation means 202. The correction coefficient α of the above, the preset electric capacity adjustment coefficient Ka for the auxiliary machine, and the preset electric capacity KBw when the battery is fully charged are used to calculate the electric capacity SOCax for the auxiliary machine. Furthermore, using the prohibited area KSOCLim, which has a risk of damage to the preset battery 106, the auxiliary battery electric capacity SOCax, and other preset margins KSOCz, the battery SOC minimum remaining capacity SOCMin. Is calculated. A specific calculation method will be described with reference to the flow chart of FIG. 3 described later.

The SOC estimated value calculation means 204 uses the initial battery SOC value KSOCi, the battery full-charged electric capacity KBw of the battery 106, and the battery current Ibatt detected by the battery current sensor 118 to obtain the SOC estimated value SOCe of the battery 106. calculate. The charging and discharging of the battery 106 involves a complicated chemical reaction, and it is common to estimate the SOC in order to confirm the current state of charge. A specific calculation method will be described with reference to the flow chart of FIG. 3 described later.

The engine power generation area determination means 205 includes a battery SOC minimum remaining capacity SOCMin calculated by the SOC minimum remaining capacity calculating means 203, an SOC estimated value SOCe calculated by the SOC estimated value calculating means 204, and a predetermined SOC value KSOCd. Is used to determine whether or not the area is for engine power generation. A specific region determination method will be described with reference to the flow chart of FIG. 3 described later.

The fuel consumption rate calculation means 206 requires the fuel consumption rate BSFCb when the engine power generation is not executed and the fuel consumption rate BSFCg when the engine power generation is assumed to be the current engine rotation speed Ne. Calculated using a fuel consumption rate (BSFC: Brake Specific Fuel Consumption) map based on the total engine shaft torque Te. A specific calculation method will be described with reference to the flow chart of FIG. 3 described later.

The engine power generation implementation determination means 207 is based on the fuel consumption rate BSFCb calculated by the fuel consumption rate calculation means 206 when the engine power generation is not executed and the fuel consumption rate BSFCg when the engine power generation is assumed to be performed. , Judge whether to carry out engine power generation. A specific determination method will be described with reference to the flow chart of FIG. 3 described later.

The engine power generation implementing means 208 carries out engine power generation when the result determined by the engine power generation executing determining means 207 is affirmative.

Next, in the vehicle system including the control device of the hybrid vehicle shown in FIG. 1, when the SOC of the battery is low, an SOC region is provided in which it is possible to select whether or not to perform engine power generation according to the use of auxiliary equipment. A control for performing engine power generation only when the fuel consumption rate is estimated to be small even if engine power generation is performed in that region will be described with reference to the flowchart of FIG. The operation described below is performed in the vehicle ECU 114 as a subroutine in the main routine having a predetermined time cycle.

FIG. 3 is a flowchart showing the operation of the control device of the hybrid vehicle according to the first embodiment. In FIG. 3, first, in step S300, in order to determine whether initialization is necessary, it is determined whether or not the ignition switch is immediately turned on. If the ignition switch is immediately turned on (YES), the process proceeds to step S301. If the ignition switch is not immediately turned on (NO), the process proceeds to step S302.

When the process proceeds from step S300 to step S301, the initialization process of the control device 1000 of the hybrid vehicle is performed. In the initialization process, "0" is set as an initial value for the value calculated by each means described later, and when the initialization is completed, the subroutine is terminated as it is.

From step S300 to step S302, the auxiliary machine power consumption calculation means 201 calculates the auxiliary machine current consumption amount Hw [Ah] as the amount of electricity by using the auxiliary machine power consumption calculation means 201 using the current consumption current Iaux [A] of the auxiliary machine 107. The auxiliary machine current consumption amount Hw [Ah] is calculated by integrating the auxiliary machine 107 current consumption Iux [A] only for a preset time. In the first embodiment, the preset time is set to 100 [sec]. The calculated auxiliary current consumption amount Hw [Ah] is written in the backup RAM every 100 [sec]. If the ignition switch is turned off and the integration is not performed for 100 [sec] during the calculation of the auxiliary current consumption Hw, the measured value should be converted to around 100 [sec] and used. do.

In the first embodiment, the preset time is set to 100 [sec], but the time is not limited to this, and another time may be provided. For example, the time of one driving cycle (ignition switch is turned on). It may be the time from when the vehicle runs until the ignition switch is turned off).

Next, in step S303, the auxiliary machine current consumption correction coefficient α is obtained by the auxiliary machine current consumption correction coefficient calculation means 202 using the auxiliary machine current consumption amount Hw [Ah] calculated in step S302. The correction coefficient α for the auxiliary current consumption is determined with reference to the map of FIG. 4 according to the deviation (inclination) between the latest value of the auxiliary current consumption Hw [Ah] and the previous value. .. That is, FIG. 4 is an explanatory diagram showing an example of a map for calculating the correction coefficient α in the control device of the hybrid vehicle according to the first embodiment and the second embodiment described later. As shown in FIG. 4, the value of the correction coefficient α increases as the deviation (slope) increases. As a result, when the auxiliary machine current consumption amount Hw [Ah] suddenly changes due to the sudden use of the auxiliary machine 107 by the driver, it is corrected by a large value.

The calculation method of the correction coefficient α is not limited to the deviation (slope) as shown in FIG. 4, and other calculations such that the correction coefficient α becomes larger as the driver's use of auxiliary equipment increases rapidly. The method may be used.

In FIG. 3, when proceeding from step S303 to step S304, first, the auxiliary machine current consumption amount Hw [Ah] calculated in step S302 and the correction coefficient α of the auxiliary machine current consumption amount calculated in step S303 are set in advance. The auxiliary battery electric capacity SOCax is calculated from the following formula (1) by using the auxiliary electric capacity adjustment coefficient Ka and the preset electric capacity KBw when the battery is fully charged.
SOCax [%] = Hw [Ah] x Ka x α / KBw [Ah] x 100 ... Equation (1)

The auxiliary machine electric capacity adjustment coefficient Ka in the equation (1) is a coefficient of how much electric capacity is secured in the battery 106 with respect to the auxiliary machine current consumption amount Hw [Ah], and for example, "1" is It is set. The electric capacity KBw when the battery is fully charged is set to a unique value which is the maximum electric capacity of the battery 106.

In the first embodiment, the correction coefficient α for the auxiliary current consumption in the equation (1) is corrected by multiplying the auxiliary current consumption Hw [Ah], but is limited to this. It may be corrected by adding the correction coefficient α to the auxiliary current consumption amount Hw [Ah].

Next, in step S304, the use-prohibited area KSOCLim at which there is a risk of damage to the preset battery 106, the auxiliary battery electric capacity SOCax calculated by the equation (1), and the preset other margin KSOCz. , The SOC minimum residual capacity SOCMin of the battery is calculated from the following equation (2) by the SOC minimum residual capacity calculation means 203.
SOCMin [%] = KSOCLim [%] + SOCax [%] + KSOCz [%]
… Equation (2)

FIG. 5 is an explanatory diagram showing the configuration of the minimum SOC remaining capacity in the control device of the hybrid vehicle according to the first embodiment and the second embodiment described later, and is the first embodiment represented by the equation (2) and the second embodiment. The SOC minimum remaining capacity in the case of the second embodiment is schematically shown in comparison with the SOC minimum remaining capacity in the comparative example. Generally, the battery 106 has a prohibited area of SOC for avoiding a risk such as damage, and the prohibited area KSOCLim in the formula (2) corresponds to the area. A margin is generally provided so that the SOC does not fall below this prohibited area KSOCLim. In the comparative example shown in FIG. 5, the SOC minimum remaining capacity of the battery is composed of a “prohibited area” and a “other margin” for avoiding risks such as damage, and the “prohibited area” and the “other margin”. Is set as a fixed value of the SOC minimum remaining capacity. Here, the "other margin" in the comparative example includes an estimation error in estimating SOC, a vehicle restart portion, an auxiliary machine drive portion, and the like.

On the other hand, in the case of the first embodiment and the second embodiment, as shown in the formula (2) and FIG. 5, the SOC minimum remaining capacity is "prohibited area KSOCLim [%]" and "other margin KSOCz". It is composed of "[%]" and "auxiliary drive component SOCax [%]", and "use prohibited area KSOCLim [%]" and "other margin KSOCz" are set as fixed values, and "auxiliary machine drive component SOCax [%]". %] ”Is the area that changes depending on the driver. Here, the “auxiliary drive component SOCax [%]” corresponds to the accessory drive component in the fixed value “other margin” in the comparative example. The “other margin KSOCz [%]” in the first and second embodiments includes an estimation error in estimating the SOC, a restart of the vehicle, and the like. In FIG. 5, the auxiliary battery electric capacity SOCax calculated by the equation (1) is referred to as “auxiliary drive component SOCax [%]”.

Next, in step S305 of FIG. 3, the current SOC estimated value calculation means 204 uses the battery current Ibatt detected by the battery current sensor 118 and KSOCi, which is the initial SOC value stored in the backup RAM. The SOC estimated value SOCe is calculated in order to grasp the charge state of the battery 106. The SOC estimated value SOCe integrates the battery current Ibatt over time, and calculates how much current is currently stored with respect to the electric capacity KBw when the battery is fully charged from the following equation (3).
SOCe [%] = KSOCi [%]
+ ∫ (Ibatt [A] dt) / KBw [Ah] / 3600 × 100
… Equation (3)

The SOC estimated value SOCe calculated by the equation (3) is stored in the backup RAM when the ignition switch is turned off. The equation (3) is an example of the SOC estimated value calculation method, and may be calculated using other well-known techniques.

In step S306, the engine power generation area determination means 205 uses the battery SOC minimum remaining capacity SOCMin calculated in step S304, the SOC estimated value SOCe calculated in step S305, and the predetermined SOC value KSOCd stored in the ROM. Judgment is made by. Specifically, the engine power generation area determination means 205 determines whether or not [battery SOC minimum remaining capacity SOCMini <SOC estimated value SOCe <KSOCd] is satisfied, and if it is satisfied (YES), the engine. It is determined that the area is power generation, the engine power generation area determination flag FJde is set to "1", the process proceeds to step S308, and if it is not satisfied (NO), the engine power generation area determination flag FJde is set to "0". Then, the process proceeds to step S307.

Here, in the first embodiment, the predetermined SOC value KSOCd stored in the ROM is set as a threshold value for carrying out engine power generation in the conventional control. In the conventional control, the engine power generation is controlled while [SOC estimated value SOCe <KSOCd] is established. Further, the SOC value KSOCd used in the first embodiment is provided with a hysteresis according to the increase / decrease of the SOC, and the SOC estimated value SOCe is compared with the SOC value KSOCd when the SOC estimated value SOCe is decreasing. The SOC value KSOCd when is increasing is set to a slightly larger value. By providing hysteresis in the threshold value in this way, it is possible to avoid a state in which engine power generation must be performed again immediately after engine power generation is completed.

As a result of the determination in step S306, the engine power generation area determination flag FJde becomes "0", and when the process proceeds to step S307, in step S307, whether or not the SOC estimated value SOCe is equal to or less than the battery SOC minimum remaining capacity SOC Min. If the judgment is made and [Battery SOC minimum remaining capacity SOCMin ≥ SOC estimated value SOCe] (YES), it is judged that the minimum battery capacity has not been secured and it is necessary to immediately perform engine power generation, and the engine is used. The power generation execution permission flag FGen is set to "1" and the process proceeds to step S311.

As a result of the determination in step S307, when [Battery SOC minimum remaining capacity SOCMin ≧ SOC estimated value SOCe] is not established (NO), it is determined that engine power generation is unnecessary because it is in the state of [SOC estimated value SOCe ≧ KSOCd]. Then, the engine power generation execution permission flag FGen is set to "0", the total engine shaft torque Te1 for the vehicle drive described later is output as the total engine shaft torque Te from the vehicle ECU 114 to the engine ECU 112, and the subroutine is terminated. The engine ECU 112 controls the engine 101 so that the total engine shaft torque Te1 becomes the total engine shaft torque Te.

On the other hand, as a result of the determination in step S306, the engine power generation area determination flag FJde becomes "1", and the process proceeds to step S308. The fuel consumption rate BSFCb is calculated by the consumption rate calculation means 206 when it is assumed that the engine power generation has not been performed at the current operation point. As for the engine shaft total torque Te1 when calculating the fuel consumption rate BSFCb when it is assumed that the engine power generation has not been implemented, the torque of the vehicle drive component torque Teb becomes the engine shaft total torque Te1 as it is, as shown in the following equation (4). ..
Te1 = Teb ... Equation (4)

Here, the vehicle drive torque Teb is the torque of the engine shaft required to drive the vehicle in response to the driver's accelerator operation, and is, for example, a preset map according to the current vehicle speed and accelerator opening degree. It is calculated by. Next, from the total engine shaft torque Te1 calculated by the equation (4) and the engine rotation speed Ne, the fuel consumption rate BSFCb when it is assumed that the engine power generation is not implemented is calculated by using a preset fuel consumption rate map. It is calculated by the following formula (5).
BSFCb [g / kWh] = MAP (Ne [rpm], Te1 [Nm]) ... Equation (5)

The fuel consumption rate map used in the formula (5) is shown in FIG. That is, FIG. 6 is an explanatory diagram showing an example of a fuel consumption rate map in the control device of the hybrid vehicle according to the first embodiment and the second embodiment described later. In the fuel consumption rate map shown in FIG. 6, the horizontal axis represents the engine rotation speed Ne and the vertical axis represents the total engine shaft torque Te, and the fuel consumption rate is shown by contour lines. The map shown in FIG. 6 shows that the more the contour lines are in the center, the smaller the fuel consumption rate and the better the fuel consumption, and the more the contour lines are on the outside, the larger the fuel consumption rate and the worse the fuel consumption. .. The fuel consumption rate map shown by the contour lines shows the characteristics of the engine 101, and the characteristics of the engine are measured in advance by actual machine tests, simulations, etc. and set as a map.

Next, in step S309 of FIG. 3, it is assumed that engine power generation is performed at the current operating point by the fuel consumption rate calculation means 206 using the engine rotation speed Ne and the engine shaft total torque Te in the same procedure as in step S308. Calculate the fuel consumption rate BSFCg at that time. As shown in the following equation (6), the total engine shaft torque Te2 used to obtain the fuel consumption rate BSFCg when assuming the implementation of engine power generation at the current operating point is the engine power generation torque Teg and the vehicle drive component. The torque obtained by adding the torque Teb is used.
Te2 = Teg + Teb ... Equation (6)

FIG. 7 is an explanatory diagram showing the engine shaft torque when it is assumed that the engine power generation is not performed and when the engine power generation is assumed, and the equations (4) and (6) are schematically shown in the figure. It is a representation. As shown in FIG. 7, the total engine shaft torque Te1 when it is assumed that the engine power generation has not been performed, that is, the total engine shaft torque Te is the same torque as the vehicle drive torque Teb, whereas the engine power generation is assumed. In this case, the total engine shaft torque Te2, that is, the total engine shaft torque Te, is obtained by adding the engine power generation torque Teg to the vehicle drive torque Teb.

FIG. 8 is an explanatory diagram showing a fuel consumption rate map in the control device of the hybrid vehicle according to the comparative example. In the comparative example, the fuel consumption rate at the operation point P1 when the implementation of engine power generation is assumed and the engine power generation are shown. It shows the difference from the fuel consumption rate at the operation point P2 when it is assumed that it has not been implemented. The vertical axis, horizontal axis, and contour lines in FIG. 8 are the same as those in FIG. 6 described above. As shown in FIG. 8, the fuel consumption rate at the operation point P1 when the engine power generation is assumed is the engine power generation torque Teg, as compared with the fuel consumption rate at the operation point P2 when the engine power generation is not executed. Is added to increase the total engine shaft torque Te, and it can be seen that the fuel consumption rate increases accordingly. In the control according to the comparative example, the fuel consumption rate may increase depending on the operating point at which the engine power generation is performed, and in that case, the fuel consumption tends to deteriorate.

Next, in step S309 of FIG. 3, from the total engine shaft torque Te2 calculated by the formula (6) and the engine rotation speed Ne, the fuel consumption when it is assumed that the engine power generation is carried out by using the following formula (7). Calculate the rate BSFCg.
BSFCg [g / kWh] = MAP (Ne [rpm], Te2 [Nm]) ... Equation (7)

From step S309 to step S310, in step S310, the fuel consumption rate BSFCb calculated in step S308 assuming that the engine power generation has not been performed and the fuel consumption rate calculated in step S309 assuming the execution of engine power generation are assumed. Whether or not [fuel consumption rate BSFCg when engine power generation is assumed <fuel consumption rate BSFCb when engine power generation is not performed] is satisfied by the engine power generation implementation determination means 207 using BSFCg. Make a judgment. As a result of the determination in step S310, if [fuel consumption rate BSFCg assuming the implementation of engine power generation <fuel consumption rate BSFCb assuming the non-execution of engine power generation] is satisfied (YES), the execution condition of the engine power generation is satisfied. Assuming that it is established, the engine power generation execution permission flag FGen is set to "1" and the process proceeds to step S311.

On the other hand, if [fuel consumption rate BSFCg when engine power generation is assumed to be performed <fuel consumption rate BSFCb when engine power generation is not to be performed] is not established in the determination in step S310 (NO), engine power generation Assuming that the implementation judgment is unsuccessful, the engine power generation execution permission flag FGen is set to "0", the total engine shaft torque Te1 for the vehicle drive is output as the total engine shaft torque Te from the vehicle ECU 114 to the engine ECU 112, and a subroutine is used. To finish.

In step S311, the engine power generation execution permission flag FGen is set to "1" by the determination in step S310 or step S307, and the total engine shaft torque Te2 including the torque for the engine power generation is set as the total engine shaft torque Te for the vehicle. The engine 101 is controlled by outputting the output from the engine 114 to the engine ECU 112. Further, the vehicle ECU 114 outputs the engine power generation torque Teg to the MG ECU 113, and the MG 105 is controlled so as to generate the power for the engine power generation torque Teg in the MG ECU 113. As a result, engine power generation is performed and the battery 106 is charged. After step S311 the subroutine is terminated.

Next, an example of the operation of the control device of the hybrid vehicle according to the first embodiment described above will be described using a timing chart. FIG. 9 is a timing chart illustrating the operation of the control device of the hybrid vehicle according to the first embodiment. In FIG. 9, (A) is the vehicle speed, (B) is the engine speed Ne, (C) is the total engine shaft torque Te, (D) is the SOC estimated value SOCe, (E) is the fuel consumption rate, and (F) is. Fuel consumption, (G) is fuel consumption, (H) is an engine power generation area determination flag FJde, (I) is an engine power generation execution permission flag FGen, and the horizontal axis shows time. The broken line in FIG. 9 shows the operation of the comparative example with respect to the first embodiment.

As shown in FIG. 9, if the MG 105 is driven and the auxiliary machine 107 is used while the vehicle speed of (A) is accelerating, the SOC estimated value SOCe of (D) gradually decreases with the passage of time. At the timing T1, the SOC estimated value SOCe of (D) becomes equal to or less than the predetermined SOC value KSOCd, so that "1" is set in the engine power generation area determination flag FJde of (H). In the control according to the comparative example, at this timing T1, the engine power generation execution permission flag FGen of (I) becomes "1" as shown by the broken line, the engine power generation is started, the battery 106 is charged, and the SOC estimation of (D) is performed. The value SOC increases as shown by D1. Since the engine power generation at this time is the engine power generation at the operating point where the fuel consumption rate is relatively large, the fuel consumption in (F) becomes large as shown by F1, and the fuel consumption rate in (E) is E1. It deteriorates as shown, and the fuel consumption of (G) deteriorates as shown by G1. At this time, in the comparative example, the total engine shaft torque Te of (C) is increased by the engine power generation torque Teg as shown by C1.

On the other hand, in the case of the first embodiment, as described above, the fuel consumption rate when the engine power generation is assumed is compared with the fuel consumption rate when the engine power generation is assumed, and the engine power generation is not carried out. Since it is determined that the fuel consumption rate is small (good fuel consumption) when assumed, the SOC estimated value SOCe of (D) becomes equal to or less than the predetermined SOC value KSOCd at timing T1, and the engine of (H) Even if "1" is set in the power generation area determination flag FJde, engine power generation is not performed from timing T1 to timing T2. Therefore, the SOC estimated value SOCe in (D) continues to decrease due to the use of the auxiliary machine 107, but it does not fall below the battery SOC minimum remaining capacity SOCMin calculated according to the use of the auxiliary machine 107, so that the engine It doesn't matter if you don't generate electricity.

Next, at the timing T2, as described above, in the first embodiment, it is determined that the fuel consumption rate when the engine power generation is assumed is smaller than the fuel consumption rate when the engine power generation is not performed. , The engine power generation execution determination is established, and "1" is set as shown by the solid line in the engine power generation execution permission flag FGen of (I). When the engine power generation execution permission flag FGen of (I) becomes "1", engine power generation is started. As a result, the battery 106 is charged and the SOC estimated value SOCe of (D) increases as shown by D2. Since the engine power generation at this operation point is the power generation at the operation point where the fuel consumption rate is small as shown by E2 in the fuel consumption rate of (E), the fuel consumption amount of (F) is shown by F2. As described above, it is less than F1 in the above-mentioned comparative example, and the fuel consumption of (G) does not deteriorate as in G1 of the comparative example as shown in G2. In the first embodiment, the total engine shaft torque Te of (C) increases by the engine power generation torque Teg as shown by C2 at the timing T2.

Further, as described above, engine power generation is performed until the estimated SOC value SOCe reaches a value obtained by adding the hysteresis amount to the predetermined SOC value KSOCd. Therefore, in the comparative example, at the timing T11, the engine power generation execution permission flag of (I) becomes “0”, and the engine power generation ends. On the other hand, in the first embodiment, at the timing T3, the engine power generation execution permission flag of (I) becomes "0", and the engine power generation ends.

Here, the difference in operation during engine power generation between the comparative example and the control by the control device of the hybrid vehicle according to the first embodiment will be described using a fuel consumption rate map. FIG. 10 is an explanatory diagram showing the operation of the control device of the hybrid vehicle according to the first embodiment on a fuel consumption rate map. FIG. 10 shows an engine operating point superimposed on a fuel consumption rate map. In the control of the comparative example shown by the broken line in FIG. 10, as described above, since the engine power generation is performed immediately when the engine power generation is required, the fuel for the engine power generation is required, and the operation in the first embodiment shown by the solid line is required. Engine power generation is performed at operating point B, which has a fuel consumption rate higher than the fuel consumption rate at point A, and fuel efficiency is deteriorated.

On the other hand, in the control according to the first embodiment, the fuel consumption rate BSFCg when the engine power generation is assumed to be carried out and the fuel consumption rate BSFCb when the engine power generation is not carried out satisfy the relationship of [BSFCg <BSFCb]. When it is determined that the engine power is generated, the engine power is generated at the operation point D, which has a fuel consumption rate smaller than the fuel consumption rate at the operation point C in the comparative example shown by the broken line, and the engine power generation is performed at the time of engine power generation. The fuel consumption will be improved.

The engine power generation started from the timing T2 in FIG. 9 is continued until the timing T3 at which the SOC estimated value SOCe of (D) reaches the KSOCd to which the hysteresis is added, and if the KSOCd to which the hysteresis is added is reached, ( "0" is set in the engine power generation area determination flag FJde of H) and the engine power generation execution permission flag FGen of (I), and the engine power generation ends. As described above, when the SOC of the battery 106 is low, an SOC area is provided in which it is possible to select whether or not to perform engine power generation according to the use of the auxiliary machine 107, and engine power generation is performed when the fuel consumption rate is low. By implementing the above, it is possible to improve the fuel consumption at the time of engine power generation.

The timing chart of FIG. 9 shows a case where the amount of the auxiliary machine 107 used is relatively small and the change in the amount of the auxiliary machine 107 used is small, that is, the case where the correction coefficient of the auxiliary machine current consumption is small. It is a timing chart when the battery SOC minimum remaining capacity SOC Min is a relatively low value.

FIG. 11 is a timing chart illustrating another example of the operation of the control device of the hybrid vehicle according to the first embodiment, in which the auxiliary machine current consumption is corrected when the usage amount of the auxiliary machine 107 suddenly changes. The coefficient shows the operation when the battery SOC minimum remaining capacity SOCMin is high. In FIG. 11, (A) is the vehicle speed, (B) is the engine rotation speed Ne, (C) is the total engine shaft torque Te, (D) is the SOC estimated value SOCe, (E) is the fuel consumption rate, and (F) is. Fuel consumption, (G) is fuel consumption, (H) is an engine power generation area determination flag FJde, (I) is an engine power generation execution permission flag FGen, and the horizontal axis shows time. The broken line in FIG. 11 shows the operation of the comparative example with respect to the first embodiment.

In FIG. 11, since the use of the auxiliary machine 107 increased sharply immediately before the operation shown in FIG. 11, the correction coefficient α became large, and the value of the battery SOC minimum remaining capacity SOCMin described in (D) was compared with the case of FIG. It is a large value. Therefore, the area of SOC in which it is possible to select whether or not to carry out engine power generation is narrowing.

As shown in FIG. 11, if the MG 105 is driven and the auxiliary machine 107 is used while the vehicle speed of (A) is accelerating, the SOC estimated value SOCe of (D) gradually decreases with the passage of time. At the timing T1, the SOC estimated value SOCe of (D) becomes equal to or less than the predetermined SOC value KSOCd, so that "1" is set in the engine power generation area determination flag FJde of (H). In the control according to the comparative example, at this timing T1, the engine power generation execution permission flag FGen of (I) becomes "1" as shown by the broken line, the engine power generation is started, the battery 106 is charged, and the SOC estimation of (D) is performed. The value SOC increases as shown by D1. Since the engine power generation at this time is the engine power generation at the operating point where the fuel consumption rate is relatively large, the fuel consumption in (F) becomes large as shown by F1, and the fuel consumption rate in (E) is E1. It deteriorates as shown, and the fuel consumption of (G) deteriorates as shown by G1. In this comparative example, the total engine shaft torque Te of (C) increases by the engine power generation torque Teg as shown by C1.

On the other hand, in the control according to the first embodiment, the engine power generation area determination flag FJde of (H) is "1" between the timing T1 and the timing T21, but it is determined that the engine power generation is not performed. Therefore, the engine power generation execution permission flag FGen of (I) is "0", and in the case of the first embodiment, the engine power generation is not carried out.

However, at the timing T21, the SOC estimated value SOCe of (D) becomes equal to or less than the battery SOC minimum remaining capacity SOCMin (SOCMin ≧ SOCE), and the minimum battery capacity cannot be secured. Therefore, the engine of (I) The power generation permission flag FGen is set to "1" and engine power generation is immediately performed. When the use of the auxiliary machine 107 increases rapidly in this way, the minimum capacity that must be secured in the battery 106 must also be increased. Therefore, in the first embodiment, the use of the auxiliary machine 107 increases. Therefore, when the SOC estimated value SOCe falls below the changed battery SOC minimum remaining capacity SOCMin, the engine power generation is controlled to be performed immediately.

As described above, since the use of the auxiliary machine 107 increased sharply immediately before the operation shown in FIG. 11, the correction coefficient α became large, and the value of the battery SOC minimum remaining capacity SOCMin became larger than that in the case of FIG. Since the SOC area in which it is possible to select whether or not to perform engine power generation is narrowing, engine power generation is performed at timing T21 earlier than timing T2 in FIG.

When the engine power generation is performed at the timing T21, the battery 106 is charged and the SOC estimated value SOCe of (D) increases as shown by D2. Until timing T2, the fuel consumption rate of (E) temporarily increases as shown by E2, but when timing T2 is reached, power is generated at an operating point where the fuel consumption rate is small as shown by E2. , The fuel consumption of (F) is also reduced, and the fuel consumption of (G) does not deteriorate significantly as shown in G2 as in the comparative example G1. In the first embodiment, the total engine shaft torque Te of (C) increases by the engine power generation torque Teg as shown by C2 at the timing T21.

Further, as described above, engine power generation is performed until the estimated SOC value SOCe reaches a value obtained by adding the hysteresis amount to the predetermined SOC value KSOCd. Therefore, in the comparative example, at the timing T11, the engine power generation execution permission flag of (I) becomes “0”, and the engine power generation ends. On the other hand, in the first embodiment, at the timing T3, the engine power generation execution permission flag of (I) becomes "0", and the engine power generation ends.

As described above, according to the control device of the hybrid vehicle according to the first embodiment, when the SOC of the battery 106 is lowered, whether or not to use the auxiliary machine 107 and to generate engine power according to the change thereof. By providing a selectable SOC area and performing engine power generation when the fuel consumption rate is small, it is possible to improve fuel efficiency while reliably securing the SOC that must be secured at the minimum in the battery 106.

Embodiment 2.
Next, the control device for the hybrid vehicle according to the second embodiment will be described. In the second embodiment described below, when the SOC of the battery is low, the area of the SOC in which it is possible to select whether or not to perform engine power generation according to the use of the auxiliary machine and the change in the usage state of the auxiliary machine is provided. In that area, engine power generation is performed when the fuel consumption rate of engine power generation is estimated to be small when the use of auxiliary equipment is suppressed, and control is performed so that auxiliary equipment is also suppressed. .. In the following description, the parts different from those in the first embodiment will be mainly described.

FIG. 12 is a block diagram showing a control device for a hybrid vehicle according to a second embodiment, and is stored in a vehicle ECU 114 (see FIG. 1). The hybrid vehicle control device 1000 stored in the vehicle ECU 114 is configured to control the power generation of the MG 105 by the engine 101 at an appropriate timing, and is configured to control the auxiliary power consumption calculation means 201 and the auxiliary machine current consumption correction coefficient. Calculation means 202, SOC minimum remaining capacity calculation means 203, SOC estimated value calculation means 204, engine power generation area determination means 205, fuel consumption rate calculation means 206, engine power generation implementation determination means 207, engine power generation implementation means 208, auxiliary power suppression The minute torque calculation means 209 and the auxiliary machine suppression implementing means 210 are provided, and the programs and fixed value data constituting these means are stored in the ROM. Further, the initial battery SOC value KSOCi and the auxiliary current consumption amount Hw immediately before the ignition switch is turned off are stored in the backup RAM as the battery SOC value immediately before the ignition switch is turned off.

The auxiliary power suppression component torque calculation means 209 calculates the auxiliary machine power suppression component torque Theh using the auxiliary machine power consumption current amount Hw [Ah] calculated by the auxiliary machine power consumption calculation means 201. A specific calculation method will be described with reference to the flow chart of FIG. 13 described later. The auxiliary equipment suppression implementing means 210 implements auxiliary equipment suppression according to the result determined by the engine power generation implementation determining means 207. Other means are as described in FIG.

FIG. 13 is a flowchart showing the operation of the control device of the hybrid vehicle according to the second embodiment, and shows the control of the control device 1000 shown in FIG. 12 with respect to the hybrid vehicle configured as shown in FIG. In FIG. 13, steps S400 to S410 correspond to steps S300 to S310 in FIG. 3 described above, and are the same as the control in the corresponding step of FIG. 3, so the description thereof will be omitted.

As a result of the determination in step S410, [fuel consumption rate BSFCg when assuming the implementation of engine power generation <fuel consumption rate BSFCb when assuming the implementation of engine power generation] was not satisfied, and the execution determination of engine power generation was unsuccessful. In the case (NO), the process proceeds to step S411, and the auxiliary power suppression component torque Teh is calculated by the auxiliary machine power suppression component torque calculation means 209 using the auxiliary machine power consumption current consumption Hw [Ah] calculated in step S402.

FIG. 14 is an explanatory diagram showing the relationship between the auxiliary machine current consumption amount and the auxiliary machine power suppression component torque in the control device of the hybrid vehicle according to the second embodiment. In step S411, the auxiliary machine power suppression component torque calculation means 209 calculates the auxiliary machine power suppression component torque Teh according to the auxiliary machine power consumption suppression amount Hw [Ah] based on the characteristics shown in FIG. As shown in FIG. 14, the larger the auxiliary machine current consumption amount Hw [Ah] is, the smaller the auxiliary machine power suppression torque Teh is.

In the second embodiment, the torque Teh for the auxiliary machine power suppression is calculated according to the auxiliary machine current consumption amount Hw [Ah], but the present invention is not limited to this, and the torque is calculated back from the fuel consumption rate map. Therefore, it may be calculated by another method such as calculating the torque Teh for the auxiliary power suppression so as to always take an operating point where the fuel consumption rate is small.

Next, in step S412 of FIG. 13, it is assumed that the engine power generation torque is suppressed at the current operation point by the fuel consumption rate calculation means 206 using the engine rotation speed Ne and the engine shaft total torque Te. The fuel consumption rate BSFCh at that time is calculated. As shown in the following equation (8), the total engine shaft torque Te3 when calculating the fuel consumption rate BSFCh when it is assumed that the engine power generation torque is suppressed and the engine power generation is performed is the engine power generation torque Teg and the vehicle. The total engine shaft torque Te3 is obtained by subtracting the auxiliary power suppression torque Teh calculated in step S411 from the torque obtained by adding the drive torque Teb.
Te3 = Teg + Teb-Teh ... Equation (8)

Using the following formula (9) from the total engine shaft torque Te3 calculated by the formula (8) and the engine rotation speed Ne, the fuel consumption rate BSFCh when it is assumed that the engine power generation torque is suppressed and the engine power generation is performed. Is calculated.
BSFCh [g / kWh] = MAP (Ne [rpm], Te3 [Nm]) ... Equation (9)

Next, in step S413, the fuel consumption rate BSFCb calculated in step S408 assuming that engine power generation has not been executed and the fuel when engine power generation is assumed to be performed by suppressing the amount of engine power generation torque calculated in step S412. Using the consumption rate BSFCh, the engine power generation implementation determination means 207 [fuel consumption rate when it is assumed that the engine power generation is suppressed by suppressing the engine power generation torque, and <fuel when the engine power generation is not performed. It is determined whether or not the consumption rate BSFCb] is satisfied.

As a result of the determination in step S413, when [BSFCh <BSFCb] is established (YES), it is assumed that the auxiliary equipment suppression engine power generation implementation determination is established, and the auxiliary equipment suppression engine power generation execution permission flag FGenh and the engine power generation implementation permission are established. "1" is set to the flag FGen, and the process proceeds to step S414. On the other hand, if [BSFCh <BSFCb] is not established as a result of the determination in step S413 (NO), it is considered that the execution determination of the auxiliary machine suppression engine power generation is not established, and the auxiliary machine suppression engine power generation execution permission flag FGenh and the engine "0" is set to the power generation execution permission flag FGen, and the subroutine is terminated.

From step S413 to step S414, since the auxiliary equipment suppression engine power generation execution permission flag FGenh is set to "1" in step S413, the auxiliary equipment suppression implementation means 210 suppresses the auxiliary equipment power consumption. The suppressed auxiliary power consumption is calculated based on the auxiliary power suppression torque Theh calculated in step S410. In the second embodiment, the power consumption of the auxiliary machine 107 is suppressed, but the use of the auxiliary machine 107 may be stopped.

In step S415, when the engine power generation execution permission flag FGen is set to "1" by step S410, step S407 or step S413, engine power generation is performed by the engine power generation executing means 208. At that time, the value of the total engine shaft torque Te is output from the vehicle ECU 114 to the engine ECU 112, and the engine 101 is controlled so as to be the engine shaft total torque Te in the engine ECU 112.

Further, the value of the engine power generation torque Teg ([Teg-Teh] when the auxiliary machine suppression engine power generation execution permission flag FGenh is "1") is output from the vehicle ECU 114 to the MG ECU 113, and the request is made by the MG ECU 113. The MG 105 is controlled to generate electric power corresponding to the torque generated by the engine. As a result, engine power generation is performed and the battery 106 is charged. After step S415, the subroutine is terminated.

Next, an example of the operation in the case of the second embodiment described above will be described using a timing chart. FIG. 15 is a timing chart illustrating the operation of the control device of the hybrid vehicle according to the second embodiment. In FIG. 15, (A) is the vehicle speed, (B) is the engine speed Ne, (C) is the total engine shaft torque Te, (D) is the SOC estimated value SOCe, (E) is the fuel consumption rate, and (F) is. Fuel consumption, (G) is fuel efficiency, (H) is an engine power generation area determination flag FJde, (I) is an engine power generation execution permission flag FGen, and (J) is an auxiliary machine suppression engine power generation execution permission flag FGenh. The horizontal axis shows time. The broken line in FIG. 11 shows the operation in the case of the first embodiment.

In FIG. 15, similarly to FIG. 9, the engine power generation region determination is started when the SOC estimated value SOCe falls below the predetermined SOC value KSOCd as in the timing T1 of FIG. The engine power generation area determination flag FJde is set to "1". Next, when the timing T2 is reached, in the second embodiment, as described above, [fuel consumption rate when it is assumed that the engine power generation is suppressed by suppressing the engine power generation torque BSFCh <fuel consumption when it is assumed that the engine power generation is not performed. Rate BSFCb] is determined, and "1" is set in (J) the auxiliary machine suppression engine power generation execution permission flag FGenh and (I) the engine power generation execution permission flag FGen, and the operation of the auxiliary machine 107 is suppressed. After that, start engine power generation.

As described above, in the second embodiment, by suppressing the operation of the auxiliary machine 107 at the start of engine power generation, the engine power generation torque is suppressed by the amount of the auxiliary machine suppression as shown by C3 in the total engine shaft torque Te of (C). The engine is generated. On the other hand, in the case of the above-described first embodiment, the engine power generation is carried out at the timing T3, and the total engine shaft torque Te at that time is shown in C4, and the case of the second embodiment is shown. It will be larger than C3. As described above, in the second embodiment, it is possible to generate power at the operating point where the fuel consumption rate is smaller than that in the first embodiment, the fuel consumption is smaller than that in the first embodiment, and the fuel consumption at the time of engine power generation is further improved. Can be improved.

Here, the difference in operation during engine power generation between the second embodiment and the comparative example with respect to the second embodiment will be described. FIG. 16 is an explanatory diagram showing the operation of the control device of the hybrid vehicle according to the second embodiment with a fuel consumption rate map. In FIG. 16, the vertical axis represents the total engine shaft torque Te, and the horizontal axis represents the engine speed. In the comparative example shown by the broken line in FIG. 16, since the engine power generation is performed immediately when the engine power generation is required, the engine power generation is performed at the operating point where the fuel consumption rate is relatively large, and the fuel consumption is deteriorated.

On the other hand, in the second embodiment, when [fuel consumption rate BSFCg when engine power generation is assumed <fuel consumption rate BSFCb when engine power generation is not implemented] is not established, [engine power generation torque is suppressed. Fuel consumption rate when engine power generation is assumed BSFCh <Fuel consumption rate BSFCb when engine power generation is not implemented] is used to suppress engine power generation torque to generate engine power, as shown by arrow X. Compared to the comparative example, the torque can be reduced by the amount limited by the auxiliary equipment to generate engine power, and further improvement in fuel efficiency can be achieved. In addition, in FIG. 16, the chain line Y shows the case where the above-mentioned torque suppression according to the second embodiment is not performed.

According to the hybrid vehicle control device according to the first and second embodiments described above, when the SOC of the battery is low, it is possible to select whether or not to perform engine power generation according to the use of auxiliary equipment. Since the engine power generation is performed only when the fuel consumption rate is estimated to be small even if the engine power generation is performed in the area, the fuel efficiency at the time of engine power generation can be improved. .. In addition, by correcting the SOC area where it is possible to select whether or not to generate engine power according to changes in the use of auxiliary equipment, fuel efficiency is ensured while ensuring the minimum SOC that must be secured for the battery. Can be improved. Furthermore, within the SOC area where it is possible to select whether or not to perform engine power generation, engine power generation is performed and supplemented when the fuel consumption rate of engine power generation is estimated to be small when the use of auxiliary equipment is suppressed. By suppressing the aircraft, it is possible to create a state in which the fuel consumption rate of engine power generation is reduced and improve fuel efficiency while not significantly affecting the use of auxiliary equipment by the driver.

Although the present application describes various exemplary embodiments, the various features, embodiments, and functions described in one or more embodiments are limited to the application of the particular embodiment. It can be applied to embodiments alone or in various combinations. Therefore, innumerable variations not exemplified are envisioned within the scope of the techniques disclosed in the present application. For example, it is assumed that at least one component is modified, added or omitted, and further, at least one component is extracted and combined with the components of other embodiments.

101 engine, 102 crank pulley, 103 pulley, 104 belt, 105 motor generator, 106 battery, 107 auxiliary equipment, 108 transmission, 109 differential gear, 110 drive shaft, 111 tires, 112 engine ECU, 113 MG ECU, 114 vehicle ECU, 115 vehicle speed sensor, 116 accelerator position sensor, 117 brake stroke sensor, 118 battery current sensor, 201 auxiliary power consumption calculation means, 202 auxiliary current consumption correction coefficient calculation means, 203 SOC minimum remaining capacity calculation means, 204 SOC estimated value calculation means, 205 engine power generation area determination means, 206 fuel consumption rate calculation means, 207 engine power generation implementation determination means, 208 engine power generation implementation means, 209 auxiliary power suppression torque calculation means, 210 auxiliary machine suppression implementation means

The hybrid vehicle control device disclosed in the present application is
An engine that operates by burning fuel to generate power, a motor generator that can generate power by being driven by the power of the engine, a battery that charges the power generated by the motor generator, and the battery. A hybrid vehicle control device configured to control a hybrid vehicle equipped with at least one auxiliary device that is powered by and operates from.
A battery SOC estimated value calculation means for estimating the battery SOC, and a battery SOC estimated value calculation means.
A fuel consumption rate calculation means for calculating the fuel consumption rate at the operating point of the engine, and
Auxiliary power consumption calculation means for calculating the consumption of electricity used by the auxiliary machine during a preset time when the engine is operating, and
An SOC minimum remaining capacity calculation means that estimates the minimum SOC of the battery according to the consumption amount calculated by the auxiliary power consumption calculation means.
It is determined whether or not the SOC of the battery estimated by the battery SOC estimated value calculating means is between a preset value and the minimum SOC of the battery estimated by the SOC minimum remaining capacity calculating means. Engine power generation area determination means and
When the result of the determination by the engine power generation area determination means is affirmative, at least the fuel consumption rate of the engine when the engine power generation is assumed and the fuel consumption rate of the engine when the engine power generation is not performed are assumed. An engine power generation implementation determination means for determining whether or not to execute the engine power generation based on a comparison with the fuel consumption rate of the engine.
Equipped with
When the result of the determination of the engine power generation implementation determination means is affirmative, the engine power generation is configured to be executed.
It is characterized by that.

Claims (3)

An engine that operates by burning fuel to generate power, a motor generator that can generate power by being driven by the power of the engine, a battery that charges the power generated by the motor generator, and the battery. A hybrid vehicle control device configured to control a hybrid vehicle equipped with at least one auxiliary device that is powered by and operates from.
A battery SOC estimated value calculation means for estimating the battery SOC, and a battery SOC estimated value calculation means.
A fuel consumption rate calculation means for calculating the fuel consumption rate at the operating point of the engine, and
Auxiliary power consumption calculation means for calculating the consumption of electricity used by the auxiliary machine, and
An SOC minimum remaining capacity calculation means that estimates the minimum SOC of the battery according to the consumption amount calculated by the auxiliary power consumption calculation means.
It is determined whether or not the SOC of the battery estimated by the battery SOC estimated value calculating means is between a preset value and the minimum SOC of the battery estimated by the SOC minimum remaining capacity calculating means. Engine power generation area determination means and
When the result of the determination by the engine power generation area determination means is affirmative, at least the fuel consumption rate of the engine when the engine power generation is assumed and the fuel consumption rate of the engine when the engine power generation is not performed are assumed. An engine power generation implementation determination means for determining whether or not to execute the engine power generation based on a comparison with the fuel consumption rate of the engine.
Equipped with
When the result of the determination of the engine power generation implementation determination means is affirmative, the engine power generation is configured to be executed.
A hybrid vehicle control device characterized by this. The control device is
A correction coefficient that detects that the consumption of electricity used by the auxiliary machine has changed and corrects the minimum SOC of the battery estimated by the SOC minimum remaining capacity calculation means according to the detected change in consumption. Auxiliary current consumption correction coefficient calculation means,
Have,
The control device for a hybrid vehicle according to claim 1. The control device is
Auxiliary power suppression torque calculation means for calculating engine power generation torque for suppressing the amount of electricity used by the auxiliary machine according to the amount of electricity consumed by the auxiliary machine.
Equipped with
When it is assumed that the fuel consumption rate when the engine power generation is not executed is smaller than the fuel consumption rate when the engine power generation is assumed and the engine power generation torque is suppressed by the engine power generation execution determination means. When it is determined that the fuel consumption rate of the engine is smaller than the fuel consumption rate when it is assumed that the engine power generation has not been performed, the engine power generation is performed and the amount of electricity used by the auxiliary machine is suppressed.
The control device for a hybrid vehicle according to claim 1 or 2.

Images