WO2011142022A1

WO2011142022A1 - Hybrid vehicle control device and hybrid vehicle

Info

Publication number: WO2011142022A1
Application number: PCT/JP2010/058159
Authority: WO
Inventors: 英輝鎌谷; 国明新美
Original assignee: トヨタ自動車株式会社
Priority date: 2010-05-14
Filing date: 2010-05-14
Publication date: 2011-11-17

Abstract

A control device of a hybrid vehicle includes a memory unit (13), wherein a plurality of maps are stored, said maps having a plurality of operation points recorded therein, said operation points denoting relationships between fuel consumption quantities and accumulator device charge-discharge quantities, said maps being pre-defined on a per requested drive power to the vehicle basis; and a control device (14) that selects one map from the plurality of maps according to the requested drive power, selects one operation point from the plurality of operation points upon the selected map, and controls the engine so as to correspond to the selected operation point.

Description

Hybrid vehicle control device and hybrid vehicle

The present invention relates to a hybrid vehicle control device and a hybrid vehicle, and more particularly to a hybrid vehicle control device equipped with a power storage device, a motor, and an engine.

In recent years, hybrid cars have been regarded as important due to environmental issues. Japanese Unexamined Patent Publication No. 9-98513 (Patent Document 1) is a document related to a charge / discharge control device for a hybrid electric vehicle.

This document discloses a charge / discharge control device for a hybrid electric vehicle that performs charge control for charging a battery by driving a generator with an onboard motor. This charging / discharging control device sets the charging rate at the start of initial charging and the charging rate at the end of initial charging to be lower than the optimum charging range with good charging efficiency. Then, after the initial charging, the charging rate at the start of charging and the charging rate at the end of charging are shifted to charging based on the optimal charging range through an intermediate charging process closer to the optimal charging range than the initial charging.

JP-A-9-98513 JP-A-10-215503

A study example for improving the efficiency of charge / discharge control will be described with reference to FIGS.
FIG. 17 is a diagram showing an example of a basic charge / discharge map of a hybrid vehicle.

Referring to FIG. 17, the horizontal axis indicates the state of charge (SOC: State Of Charge) (%), and the vertical axis indicates the charge / discharge amount (kW). The control device for the hybrid vehicle determines the basic charge / discharge amount based on the SOC. That is, if the current SOC of the battery matches the SOC center, the battery is not charged / discharged. If the current SOC is higher than the SOC center, the control device discharges the battery, and if the current SOC is lower than the SOC center, the control device charges the battery. By executing such control, the SOC of the battery converges near the SOC center.

FIG. 18 is a diagram illustrating an example of a charge / discharge map in consideration of efficiency.
FIG. 18 is referred to when charging is performed. The horizontal axis in FIG. 18 indicates the user requested power, and the vertical axis indicates the amount of charge. The user request power increases or decreases according to, for example, the degree of depression of the accelerator pedal.

FIG. 19 is a diagram for explaining charging in consideration of efficiency.
In FIG. 19, the engine operating line and the engine thermal efficiency contour are superimposed on a plane with the engine speed on the horizontal axis and the engine torque on the vertical axis. The thermal efficiency contour is closer to the center, and the thermal efficiency is better. Referring to FIGS. 18 and 19, the charge amount is increased to the maximum charge amount in the region where the user request power is low. This charging improves the fuel efficiency of the vehicle because the operating point moves on the engine operating line in a direction in which the thermal efficiency is improved.

If the charge amount determined in FIG. 18 is on the charge side as compared with the basic charge / discharge amount determined in FIG. 17, the charge amount determined in FIG. Control is performed.

However, in this study example, the SOC center tends to shift higher, and there is a possibility that the regenerative power during deceleration cannot be recovered. Therefore, this study example has room for further improvement on the discharge side.

An object of the present invention is to provide a hybrid vehicle control device and a hybrid vehicle with improved overall energy efficiency.

In summary, the present invention is a control device for a hybrid vehicle equipped with a power storage device, a motor, and an engine, the fuel consumption amount and the charge / discharge amount to the power storage device determined in advance for each required driving force to the vehicle. A storage unit storing a plurality of maps each storing a plurality of operation points indicating the relationship between the two, and selecting one map from the plurality of maps according to the required driving force, and a plurality of operation points on the selected map And a control device that controls the engine so as to correspond to the selected operating point.

Preferably, the control device has an operation point at which an absolute value of an inclination of a line connected to an operation point when performing EV traveling in which the engine is stopped among a plurality of operation points on the selected map is the largest. Select.

Preferably, the control device limits a range of operation points to be selected from among a plurality of operation points on the selected map based on the state of the vehicle.

More preferably, the state of the vehicle includes either the state of charge of the power storage device or the temperature of the power storage device.

More preferably, when the state of charge of the power storage device exceeds the first threshold value, the control device is set to 1 from an operating point included in a limited area so as to limit the amount of charge to the power storage device on the map. Select one operating point.

More preferably, when the state of charge of the power storage device falls below the second threshold value, the control device is configured to 1 from an operating point included in a limited area so as to limit a discharge amount from the power storage device on the map. Select one operating point.

More preferably, when the temperature of the power storage device exceeds a threshold value, the control device is included in an area limited to limit both a charge amount to the power storage device and a discharge amount from the power storage device on the map. One operating point is selected from the operating points to be operated.

More preferably, the state of the vehicle includes a vehicle speed of the vehicle.
More preferably, when the vehicle speed of the vehicle exceeds a threshold value, the control device selects one operating point from operating points included in a limited area so as to limit the amount of charge to the power storage device on the map. select.

More preferably, the state of the vehicle includes a charge / discharge integrated time of the power storage device from the initial state.
Preferably, the control device recognizes the driving pattern of the driver, and changes the operating point selected according to the driving pattern recognized from the plurality of operating points on the selected map.

In another aspect, the present invention is a hybrid vehicle equipped with any one of the above hybrid vehicle control devices.

According to the present invention, the efficiency of the hybrid vehicle is further improved and the fuel consumption is improved.

It is a figure which shows the main structures of the hybrid vehicle 1 of this Embodiment. It is the figure which showed the peripheral device related with the functional block of the control apparatus of FIG. 2 is a diagram illustrating a general configuration when a computer 100 is used as a control device 14. FIG. It is a flowchart for demonstrating the control performed with the control apparatus 14 of FIG. FIG. 6 is a diagram illustrating an example of an fc-Pb map. It is a figure for demonstrating the setting of the operating point at the time of virtual EV driving | running | working. It is the figure which showed the relationship between the inclination d and the parameter K. FIG. It is a figure for demonstrating selection of the operating point of step S32. 6 is a map in which the allowable discharge amount POUT and the allowable charge amount PIN are entered in the map of FIG. 5 and lines LA1 and LA2 are drawn. It is the figure which showed the example of a process which changes the allowable charging / discharging amount when SOC exceeds a threshold value. It is the figure which showed the example of a process which changes the allowable charging / discharging amount when SOC is less than a threshold value. It is the figure which showed the example of a process which changes the allowable charging / discharging amount when battery temperature exceeds a threshold value. It is the figure which showed the example of a process which changes the allowable charging / discharging amount when a vehicle speed exceeds a threshold value. It is a figure for demonstrating the temporary increase of the allowable charging / discharging amount in step S43. It is a figure for demonstrating a 1st modification. It is a figure for demonstrating the 2nd modification. It is the figure which showed an example of the basic charging / discharging map of a hybrid vehicle. It is the figure which showed an example of the charging / discharging map which considered efficiency. It is a figure for demonstrating the charge which considered efficiency.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof will not be repeated.

[Embodiment 1]
FIG. 1 is a diagram illustrating a main configuration of a hybrid vehicle 1 according to the present embodiment. The hybrid vehicle 1 is a vehicle that uses both an engine and a motor for traveling.

Referring to FIG. 1, hybrid vehicle 1 includes

front wheels

20R and 20L,

rear wheels

22R and 22L, an engine 2, a planetary gear 16, a differential gear 18, and gears 4 and 6.

The hybrid vehicle 1 further includes a high voltage battery BAT arranged at the rear of the vehicle, a boost unit 32 that boosts DC power output from the high voltage battery BAT, and an inverter 36 that transfers DC power between the boost unit 32, Motor generator MG1 coupled to engine 2 via planetary gear 16 and mainly generating electric power, and motor generator MG2 whose rotating shaft is connected to planetary gear 16 are included. Inverter 36 is connected to motor generators MG <b> 1 and MG <b> 2 and performs conversion between AC power and DC power from booster unit 32.

The planetary gear 16 has first to third rotating shafts. The first rotation shaft is connected to engine 2, the second rotation shaft is connected to motor generator MG1, and the third rotation shaft is connected to motor generator MG2.

The gear 4 is attached to the third rotating shaft, and the gear 4 drives the gear 6 to transmit power to the differential gear 18. The differential gear 18 transmits the power received from the gear 6 to the

front wheels

20R and 20L, and transmits the rotational force of the

front wheels

20R and 20L to the third rotating shaft of the planetary gear via the gears 6 and 4.

Planetary gear 16 plays a role of dividing power between engine 2 and motor generators MG1 and MG2. That is, if the rotation of two of the three rotation shafts of the planetary gear 16 is determined, the rotation of the remaining one rotation shaft is forcibly determined. Accordingly, the vehicle speed is controlled by controlling the power generation amount of the motor generator MG1 and driving the motor generator MG2 while operating the engine 2 in the most efficient region, thereby realizing an overall energy efficient vehicle. Yes.

It should be noted that a reduction gear that decelerates the rotation of motor generator MG2 and transmits it to planetary gear 16 may be provided, or a transmission gear that can change the reduction ratio of the reduction gear may be provided.

The high voltage battery BAT which is a DC power source includes a secondary battery such as nickel metal hydride or lithium ion, for example, and supplies DC power to the boosting unit 32 and is charged by DC power from the boosting unit 32.

The boost unit 32 boosts the DC voltage received from the high voltage battery BAT and supplies the boosted DC voltage to the inverter 36. Inverter 36 converts the supplied DC voltage into AC voltage, and drives and controls motor generator MG1 when the engine is started. Further, after the engine is started, AC power generated by motor generator MG1 is converted into DC by inverter 36, and converted to a voltage suitable for charging high voltage battery BAT by boosting unit 32, and high voltage battery BAT is charged.

Further, the inverter 36 drives the motor generator MG2. Motor generator MG2 assists engine 2 to drive

front wheels

20R and 20L. During braking, the motor generator performs a regenerative operation and converts the rotational energy of the wheels into electric energy. The obtained electrical energy is returned to the high voltage battery BAT via the inverter 36 and the boost unit 32. The high-voltage battery BAT is an assembled battery and includes a plurality of battery units B0 to Bn connected in series. System

main relays

28 and 30 are provided between the boost unit 32 and the high voltage battery BAT, and the high voltage is cut off when the vehicle is not in operation.

Hybrid vehicle 1 further includes a control device 14 and a storage unit 13. The control device 14 refers to the map stored in the storage unit 13 and determines the engine 2, the inverter 36, the boosting unit 32, and the system main relay 28 in accordance with the driver's instructions and outputs from various sensors attached to the vehicle. , 30 are controlled.

FIG. 2 is a diagram showing functional blocks of the control device 14 of FIG. 1 and related peripheral devices. The control device 14 can be realized by software or hardware.

Referring to FIG. 2, control device 14 includes a hybrid control unit 62, a battery control unit 66, and an engine control unit 68.

The battery control unit 66 calculates the high voltage battery BAT obtained by integrating the charge / discharge current of the high voltage battery BAT based on the battery current detected by the current sensor 48, the temperature sensor 49, and the voltage sensor 50, the battery temperature, and the battery voltage. The state of charge SOC is transmitted to the hybrid control unit 62.

The engine control unit 68 performs throttle control of the engine 2, detects the engine rotation speed Ne of the engine 2, and transmits it to the hybrid control unit 62.

The hybrid control unit 62 calculates an output (required power) requested by the driver based on the output signal Acc of the accelerator position sensor 42 and the vehicle speed V detected by the vehicle speed sensor. The hybrid control unit 62 calculates necessary driving force (total power) in consideration of the state of charge SOC of the high-voltage battery BAT in addition to the driver's required power, and the rotational speed required for the engine and the power required for the engine. Are further calculated. At that time, the hybrid control unit 62 refers to the map stored in the storage unit 13.

The hybrid control unit 62 transmits the required rotation speed and the required power to the engine control unit 68, and causes the engine control unit 68 to perform throttle control of the engine 2.

Hybrid control unit 62 calculates driver required torque according to the running state, causes inverter 36 to drive motor generator MG2, and causes motor generator MG1 to generate power as necessary.

The driving force of the engine 2 is distributed to a part that directly drives the wheel and a part that drives the motor generator MG1. The sum of the driving force of motor generator MG2 and the direct driving amount of the engine is the driving force of the vehicle.

Furthermore, this vehicle is provided with an EV priority switch 46. When the driver presses the EV priority switch 46, the operation of the engine is limited. As a result, the vehicle stops with the engine stopped in principle, and travels only with the driving force of motor generator MG2. The driver can press the EV priority switch 46 as necessary to reduce noise in a densely populated residential area in the middle of the night or early morning, or to reduce exhaust gas in an indoor parking lot or garage.

However, if the engine is stopped for a long time, the battery may become insufficiently charged or the necessary power may not be obtained. 1) The EV priority switch 46 is turned off. 2) The state of charge SOC of the battery Is reduced below a predetermined value, 3) if any of the conditions that the vehicle speed exceeds a predetermined value (engine start threshold) or 4) the accelerator opening exceeds a specified value, the EV priority switch 46 The on state is released.

The control device 14 described above with reference to FIG. 2 can also be realized by software using a computer.

FIG. 3 is a diagram showing a general configuration when the computer 100 is used as the control device 14.

Referring to FIG. 3, the computer 100 includes a CPU 180, an A / D converter 181, a ROM 182, a RAM 183, and an interface unit 184.

The A / D converter 181 converts analog signals AIN such as outputs from various sensors into digital signals and outputs them to the CPU 180. The CPU 180 is connected to the ROM 182, the RAM 183, and the interface unit 184 via a bus 186 such as a data bus or an address bus to exchange data.

The ROM 182 stores data such as a program executed by the CPU 180 and a map to be referred to. The RAM 183 is a work area when the CPU 180 performs data processing, for example, and temporarily stores data such as various variables.

The interface unit 184 communicates with, for example, another ECU (Electric Control Unit), inputs rewrite data when using an electrically rewritable flash memory or the like as the ROM 182, a memory card or a CD Reading data signal SIG from a computer-readable recording medium such as ROM.

Note that the CPU 180 transmits and receives the data input signal DIN and the data output signal DOUT from the input / output port.

The control device 14 is not limited to such a configuration, and may be realized by including a plurality of CPUs. Further, each of the hybrid control unit 62, the battery control unit 66, and the engine control unit 68 of FIG. 2 may have a configuration as shown in FIG.

FIG. 4 is a flowchart for explaining the control executed by the control device 14 of FIG.

Referring to FIG. 4, when the process is first started, in step S1, control device 14 reads a corresponding fc-Pb map (described later in FIG. 5) based on the required driving force. The fc-Pb map is stored in the storage unit 13 in advance. For example, when a computer is used as the control device, the fc-Pb map is stored in the ROM 182 or the RAM 183 shown in FIG.

FIG. 5 is a diagram showing an example of the fc-Pb map.
Referring to FIG. 5, the horizontal axis represents the fuel consumption fc [g / s], and the vertical axis represents the charge / discharge power Pb [kW] of the battery BAT. The charge / discharge power Pb has a sign (+) when the battery BAT is discharged and a sign (−) when the battery BAT is charged. The operating points P1 to P8 are shown on the map as to what the battery charge / discharge power Pb will be if the fuel consumption fc is consumed in order to achieve a certain required driving force. These operating points are adapted to obtain appropriate system efficiency. By performing steady running and measuring, the data of these operating points can be obtained in advance by experiments.

The operating point P1 of fc = 0 is an operating point in the case of EV traveling in which traveling is performed only by the motor with the engine stopped. The operating point P5 of Pb = 0 is an operating point when traveling with only engine power. It is assumed that the fuel consumption amount fc = f at the operating point P5. Further, at the operating points P2 to P5 where the fuel consumption amount fc is smaller than f, the required driving force cannot be realized only by the engine power, so it is necessary to assist with the motor, and the battery BAT is discharged. Conversely, at the operating points P6 to P8 where the fuel consumption amount fc is larger than f, the engine power is surplus with respect to the required driving force, so that the surplus power is used to generate power by turning the generator, and the generated power is sent to the battery BAT. Charging is performed.

The line L1 connecting the operating points P1 to P8 is a fuel-cell output line when realizing a certain value of required driving force. A map with such fuel-cell output lines drawn is determined in advance for each required driving force.

Referring to FIG. 4 again, when the reading of the fc-Pb map corresponding to the required driving force is completed in step S1, the process proceeds to step S2. In step S2, it is determined whether EV traveling is possible. This determination is determined by, for example, the required power determined by the accelerator pedal position and the vehicle speed. For example, the vehicle is set so that the engine starts when the required power is larger than a predetermined value. This vehicle setting may include various conditions.

After step S2, the search criteria determination process of step S3 is executed, and the search range of step S4 is determined following step S3. Step S3 includes the processes of steps S31 to S33, and step S4 includes the processes of steps S41 to S43.

If it is determined in step S2 that EV travel is possible, the process of step S32 is directly executed. If it is determined that EV travel is impossible, the process proceeds to step S32 after the process of step S31 is performed. .

In step S31, a line having a predetermined slope d passing through the operating point when the engine is traveling alone is drawn on the map, and the point where the fuel consumption fc = 0 (intersection with the vertical axis) is the operating point during virtual EV traveling. Set as.

FIG. 6 is a diagram for describing setting of operating points during virtual EV traveling.
Referring to FIGS. 4 and 6, with respect to the point of fc = f (the operating point for single traveling), the straight line with the inclination d1 is the line LB1, and the straight line with the inclination d2 is the line LB2. The inclinations d1 and d2 are inclinations selected according to the driving pattern of the driver. As a parameter for evaluating the running pattern, for example, a ratio of energy recovered by regeneration and energy consumed by EV running can be used.

FIG. 7 is a diagram showing the relationship between the slope d and the parameter K.
Referring to FIG. 7, the vertical axis indicates the absolute value of the slope d (because the lines LB1 and LB2 on the map of FIG. 6 are negative slope lines). The horizontal axis in FIG. 7 shows the ratio between the regenerative energy and the energy consumed by the EV travel (displayed as regenerative / EV in FIG. 7, hereinafter referred to as the regenerative / EV ratio).

For example, a driver who tends to change the amount of depression of the accelerator pedal quickly (a driver who has a rapid acceleration tendency) immediately exceeds the threshold value of the required driving force for starting the engine, and therefore tends to have less EV travel. . Such a driver has a low regeneration / EV ratio because the rate at which the regenerative energy is consumed by EV traveling is reduced.

Conversely, drivers who tend to depress the accelerator pedal slowly (drivers that do not accelerate suddenly) have a longer EV travel period. Such a driver increases the rate at which the regenerative energy is consumed by EV travel, and thus the regenerative / EV ratio decreases.

Thus, the regenerative energy and the energy consumed by EV traveling are observed for a predetermined period, and integrated to calculate the regenerative / EV ratio. As shown in FIG. 7, when the regeneration / EV ratio increases to K1 to K4, the absolute value of the slope d correspondingly increases to d1 to d4.

Referring to FIG. 6 again, when the slope selected by the driving pattern of the driver is d1, line LB1 (y = −d1 * (x−f): ordinate with the operating point of fc = f as the base point Pb is y, and the horizontal axis fc is x). The virtual EV traveling operation point PEV1 can be determined by the line LB1. This operating point PEV1 is an operating point determined corresponding to a driver who efficiently performs EV traveling.

If the slope selected by the driving pattern of the driver is d2, the line LB2 (y = −d2 * (x−f): where fc = f is the base point, where y is the vertical axis Pb and horizontal The axis fc is x). The virtual EV traveling operation point PEV2 can be determined by the line LB2. This operating point PEV2 is an operating point that is determined corresponding to a driver who is less efficient in performing EV traveling than the driver corresponding to the operating point PEV1.

Referring to FIG. 4 again, when EV traveling is possible in step S2, there is an operating point of fc = 0, and even if EV traveling is impossible in step S2, virtual EV traveling is performed by the process of step S31. An operating point is determined. Thereafter, the process of step S32 is executed.

In step S32, the operating point at the time of EV traveling on the map and other points are connected and the point with the largest inclination (the point with the large absolute value of the negative inclination) is selected and recorded.

FIG. 8 is a diagram for explaining the selection of the operating point in step S32.
Referring to FIG. 8, a line connecting an operating point during EV traveling and an operating point during engine traveling alone is defined as line LA. These two operating points are two basic operating points when the required driving force corresponding to this map is given.

Then, when considering a straight line connecting other operating points with the operating point at the time of EV traveling as a base point, a line with a negative slope steeper than the line LA (a line where the absolute value of the slope d is larger than the line LA) ) Exist. The operating point on the line where the negative slope is steeper than LA is an operating point that can efficiently charge the fuel consumption increased with respect to the operating point of the single engine operation.

In the case of FIG. 8, the operating point PS exists on the line LA1 where the negative slope is steeper than the line LA. Therefore, it is preferable to operate the hybrid system at the operating point PS as long as the SOC of the battery still has room to charge. Therefore, in principle, when the required driving force corresponding to the map of FIG. 8 is requested, either the EV travel operation point or the operation point PS is selected.

Note that a similar operation point search is performed in FIG. When the EV efficiency is good, that is, when the virtual EV traveling operation point PEV1 is selected, the line LB1S having a more negative slope than the line LB1 is determined and the operation point PS1 is selected. When the EV efficiency is low, that is, when the virtual EV traveling operation point PEV2 is selected, the line LB2S having a more negative slope than the line LB2 is determined and the operation point PS2 is selected. That is, the operating point PS1 is an optimum efficiency point when the EV efficiency is good, and the operating point PS2 is an optimum efficiency point when the EV efficiency is bad.

Referring again to FIG. 4, when the operating point PS of FIG. 8 is recorded in step S32, the process proceeds to step S33. In step S33, an allowable charge / discharge amount determined by battery constraints is set as a basic search range for searching the map. Here, a value that can protect the life of the battery is set even if this charge / discharge is permanently repeated.

FIG. 9 is a map in which the allowable discharge amount POUT and the allowable charge amount PIN are entered in the map of FIG. 5 and lines LA1 and LA2 are drawn.

Referring to FIG. 9, allowable discharge amount POUT and allowable charge amount PIN are allowable charge / discharge amounts determined by battery constraints, and are values set in step S33. The range between the allowable discharge amount POUT and the allowable charge amount PIN is the operating point search range. In FIG. 9, there are five operating points in the search range. The operating point on line LA2 has low efficiency, and the operating point on line LA1 has high efficiency. The line LA1 is an operating point at which the coefficient a of the linear equation y = ax + b is maximum in the negative direction. In this case, the operating point PS is selected as the optimal operating point unless the search range is changed in a later process.

Referring to FIG. 4 again, after the process of step S33, the search range determination process of step S4 is executed. First, in step S41, it is determined whether or not it is necessary to change the allowable charge / discharge amount set in step S33 from the vehicle speed, SOC, and battery temperature.

This determination can be made, for example, based on whether any of vehicle speed, SOC, and battery temperature exceeds or falls below a corresponding threshold value.

If it is determined in step S41 that the allowable charge / discharge amount needs to be changed, the process proceeds to step S42, and the process of changing the allowable charge / discharge amount is performed.

An example of processing for changing the allowable charge / discharge amount will be described with reference to FIGS.
FIG. 10 is a diagram illustrating a processing example of changing the allowable charge / discharge amount when the SOC exceeds the threshold value.

Referring to FIG. 10, when the SOC of the battery exceeds the upper threshold value, the battery does not have much room for charging (free capacity). Therefore, the allowable charge amount is changed from PIN to PINX. As a result, the operating point at which charging is performed is excluded from the operating point search range on the map.

FIG. 11 is a diagram showing an example of processing for changing the allowable charge / discharge amount when the SOC falls below the threshold value.

Referring to FIG. 11, when the SOC of the battery exceeds the lower threshold, discharging from the battery may cause overdischarge. Therefore, the allowable discharge amount is changed from POUT to POUTX. As a result, the operating point where the discharge is performed is excluded from the operating point search range on the map.

By performing charge / discharge control as shown in FIG. 10 and FIG. 11, it is possible to avoid an uneven convergence of the SOC center and to realize optimum charge / discharge.

FIG. 12 is a diagram showing a processing example of changing the allowable charge / discharge amount when the battery temperature exceeds the threshold value.

Referring to FIG. 12, when the battery temperature exceeds a threshold value, if the battery is charged / discharged too much, the temperature rises too much and the life of the battery is deteriorated. Therefore, the allowable charge amount is changed from PIN to PINZ, and the allowable discharge amount is changed from POUT to POUTZ. That is, the search range of the operating point is narrowed toward the zero charge / discharge line. As a result, it is possible to achieve optimum charge / discharge while avoiding an excessive temperature rise due to charge / discharge.

FIG. 13 is a diagram showing a processing example of changing the allowable charge / discharge amount when the vehicle speed exceeds the threshold value.

Referring to FIG. 13, when vehicle speed V exceeds a threshold value (during high speed driving), it is predicted that regenerative energy accompanying a large deceleration can be recovered in the future. For this reason, when traveling at a high vehicle speed, the search range is moved to the discharge side. That is, the allowable charge amount is changed from PIN to PINY. As a result, the operating point where charging is performed is excluded from the operating point search range on the map, and the operating point is selected from the operating point where discharging is performed.

By doing so, it is possible to prevent the SOC from converging higher during high-speed steady driving or the like. As a result, it is possible to prevent the regenerative power from being lost, so that the fuel efficiency improvement performance can be fully exhibited. Moreover, in order to predict the generation | occurrence | production of future regenerative electric power and to use a battery efficiently, the convergence property of SOC in various driving patterns can be improved more than before.

As described above, in step S42 in FIG. 4, the search range is changed by changing the allowable charge / discharge amount as shown in FIGS.

On the other hand, if it is determined in step S41 in FIG. 4 that it is not necessary to change the allowable charge / discharge amount in terms of vehicle speed, battery SOC, and battery temperature, the process proceeds to step S43. In step S43, if the operating point recorded in step S32 is equal to or greater than the allowable charge / discharge amount of step S33, the allowable charge / discharge amount is temporarily increased. This temporary increase is executed in a range where the increasing continuous time does not exceed a predetermined value.

FIG. 14 is a diagram for explaining a temporary increase in the allowable charge / discharge amount in step S43.

Referring to FIGS. 4 and 14, for example, when the operating point indicating the charge / discharge amount with the optimum efficiency recorded in step S33 is outside the search range, and there is no restriction on the search range due to the battery or vehicle speed (in step S41). NO) allows the search range to be temporarily extended when the continuous charge / discharge time outside the search range is equal to or shorter than a predetermined time (for example, t seconds). That is, the search range is extended only for a short time.

Then, the extended range may include an operating point that is the optimal amount of charge. By doing in this way, the charge / discharge amount whose efficiency improved compared with the past can be implement | achieved, without deteriorating battery life.

[Modification 1]
FIG. 15 is a diagram for explaining the first modification.

In FIG. 8, the efficiency line LA is drawn around the operating point during EV traveling, but the center point of the efficiency line may be the operating point during engine traveling alone as shown in FIG. In this case, the efficiency is better when the slope is gentle on the discharge side, and the efficiency is better when the slope is steep on the charge side.

However, regarding this concept, it is necessary to newly define which is more efficient for charging and discharging.

[Modification 2]
FIG. 16 is a diagram for explaining a second modification.

FIG. 16 illustrates a concept that does not have the center point of rotation of the efficiency line. The efficiency line y = ax + b is used to gradually increase b from negative, and the first point that intersects among several operating points in the search range is determined as the optimum point. With this concept, it is possible to determine engine start / stop from a single map as shown in FIG. However, since new power consumption occurs in starting / stopping the engine, if the EV travel point on the map is selected as it is, there is a high possibility that the entire system is not optimal, and the EV travel point needs to be corrected.

Finally, this embodiment will be summarized using the drawings again. Referring to FIGS. 1 and 2, the hybrid vehicle control device disclosed in the present embodiment is a hybrid vehicle control device including battery BAT, motor generators MG <b> 1 and MG <b> 2, and engine 2. The hybrid vehicle control device has a map shown in FIG. 5 in which a plurality of operating points, each of which represents a relationship between the fuel consumption amount and the charge / discharge amount to the power storage device, each predetermined for each required driving force to the vehicle are recorded. A plurality of storage units 13 and a single map selected from a plurality of maps according to the required driving force, and a single operating point selected from a plurality of operating points on the selected map. And a control device 14 that controls the engine so as to correspond to (PS of FIG. 9, PS1, PS2, etc. of FIG. 6).

Preferably, control device 14 has a line connected to an operating point (PEV1, PEV2, etc. in FIG. 6) when performing EV traveling in which the engine is stopped from among a plurality of operating points on the selected map. The operating point at which the absolute value of the slope d is the largest is selected.

Preferably, as described with reference to FIGS. 10 to 13, the control device 14 limits the range of operation points to be selected from a plurality of operation points on the selected map based on the state of the vehicle.

More preferably, as described with reference to FIGS. 10 to 12, the state of the vehicle includes either the state of charge SOC of the battery BAT or the temperature of the battery BAT.

More preferably, as shown in FIG. 10, when the state of charge SOC of battery BAT exceeds the first threshold value, control device 14 is limited to limit the amount of charge to the power storage device on the map. One operation point is selected from the operation points included in the region (the search range in FIG. 10).

More preferably, as shown in FIG. 11, control device 14 is limited to limit the amount of discharge from the power storage device in the map when the state of charge SOC of battery BAT falls below the second threshold value. One operation point is selected from the operation points included in the region (search range in FIG. 11).

More preferably, as shown in FIG. 12, when temperature T of battery BAT exceeds a threshold value, control device 14 limits both the charge amount to the power storage device and the discharge amount from the power storage device in the map. One operation point is selected from the operation points included in the limited region (the search range in FIG. 12).

More preferably, as shown in FIG. 13, the state of the vehicle includes the vehicle speed.
More preferably, as shown in FIG. 13, when the vehicle speed V of the vehicle exceeds a threshold value, the control device 14 is within an area limited to limit the amount of charge to the power storage device on the map (see FIG. 13). One operation point is selected from the operation points included in the 13 search ranges.

More preferably, the state of the vehicle includes a continuous charge / discharge time of the battery BAT. That is, the allowable charge / discharge amount may be temporarily expanded as shown in FIG. 14 within a range where the continuous charge / discharge time does not exceed the predetermined time.

More preferably, as described with reference to changing the virtual EV traveling operation point in FIG. 6, the control device 14 recognizes the traveling pattern of the driver and travels recognized from a plurality of operating points on the selected map. The operating point to be selected is changed according to the pattern.

Note that the control methods disclosed in the above embodiments can be executed by software using a computer. A program for causing a computer to execute this control method is read from a recording medium (ROM, CD-ROM, memory card, etc.) recorded in a computer-readable manner into a computer in a vehicle control device or provided through a communication line. You may do it.

The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

1 hybrid vehicle, 2 engine, 4, 6 gear, 13 storage unit, 14 control device, 16 planetary gear, 18 differential gear, 20R, 20L front wheel, 22R, 22L rear wheel, 28, 30 system main relay, 32 booster unit, 36 Inverter, 42 accelerator position sensor, 46 priority switch, 48 current sensor, 49 temperature sensor, 50 voltage sensor, 62 hybrid control unit, 66 battery control unit, 68 engine control unit, 100 computer, 181 converter, 182 ROM, 183 RAM , 184 interface unit, 186 bus, B0-Bn battery unit, BAT battery, BAT high voltage battery, MG1, MG2 motor generator.

Claims

A control device for a hybrid vehicle including a power storage device (BAT), a motor (MG1, MG2), and an engine (2),
A storage unit storing a plurality of maps each storing a plurality of operating points indicating a relationship between a fuel consumption amount and a charge / discharge amount to the power storage device (BAT), which is predetermined for each required driving force to the vehicle (13)
One map is selected from the plurality of maps according to the required driving force, and one operation point is selected from the plurality of operation points on the selected map so as to correspond to the selected operation point. A control device for a hybrid vehicle, including a control device (14) for controlling the engine.
The control device (14) has an absolute value of an inclination of a line connected to an operating point when performing EV traveling in which the engine (2) is stopped from a plurality of operating points on the selected map. The control apparatus for a hybrid vehicle according to claim 1, wherein an operating point at which the maximum value is selected is selected.
The hybrid according to claim 1, wherein the control device (14) limits a range of operation points to be selected from a plurality of operation points on the selected map based on a state of the vehicle. Vehicle control device.
4. The control apparatus for a hybrid vehicle according to claim 3, wherein the state of the vehicle includes one of a charged state of the power storage device (BAT) and a temperature of the power storage device (BAT).
The control device (14) is limited to limit the amount of charge to the power storage device (BAT) in the map when the state of charge of the power storage device (BAT) exceeds a first threshold value. The hybrid vehicle control device according to claim 4, wherein one operating point is selected from operating points included in the region.
The control device (14) is limited to limit the amount of discharge from the power storage device (BAT) in the map when the state of charge of the power storage device (BAT) falls below a second threshold value. The hybrid vehicle control device according to claim 4, wherein one operating point is selected from operating points included in the region.
When the temperature of the power storage device (BAT) exceeds a threshold value, the control device (14) determines the amount of charge to the power storage device (BAT) and the discharge from the power storage device (BAT) in the map. The hybrid vehicle control device according to claim 4, wherein one operating point is selected from operating points included in a limited region so as to limit both amounts.
4. The hybrid vehicle control device according to claim 3, wherein the state of the vehicle includes a vehicle speed of the vehicle.
When the vehicle speed of the vehicle exceeds a threshold value, the control device (14) includes an operating point included in a region limited to limit the amount of charge to the power storage device (BAT) in the map. The control apparatus of the hybrid vehicle of Claim 8 which selects one operating point from these.
4. The control apparatus for a hybrid vehicle according to claim 3, wherein the state of the vehicle includes a continuous charge / discharge time of the power storage device (BAT).
The said control apparatus (14) recognizes a driver | operator's driving | running | working pattern, and changes the operating point selected according to the driving | running | working pattern recognized from these operating points on the selected map. 11. The hybrid vehicle control device according to any one of items 10 to 10.
A hybrid vehicle equipped with the hybrid vehicle control device according to claim 11.