JP2017001533A - Vehicle control apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle control apparatus capable of reducing the possibility of deteriorating the life a power storage device in a case where an actual charge amount is controlled on the basis of a target charge amount of the device.SOLUTION: A vehicle control apparatus includes: target setup means for setting a target charge amount of a power storage device; and travel control means for controlling an engine and a second MG on the basis of an actual charge amount of the power storage device and the target charge amount. Further, the travel control means is capable of executing: a first travel mode in which control is performed to supply a battery with regenerative power from the second MG; and a second travel mode in which control is performed so that a regenerative power amount supplied from the second MG to the battery is smaller than in the first travel mode. Further, the target setup means sets a target charge amount larger in the case of a high frequency of executing the second travel mode than in the case of a low frequency.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a vehicle control device used for a hybrid vehicle or the like.

  In recent years, hybrid vehicles have become widespread as vehicles that can travel using electric energy. In this hybrid vehicle, a vehicle capable of executing one deceleration mode from among a plurality of deceleration modes having different decelerations when traveling in an accelerator-off state has been proposed (see Patent Document 1).

  Patent Document 1 describes a small deceleration mode in which the deceleration is smaller than that in the normal deceleration mode, in addition to the normal deceleration mode in which an ordinary deceleration is obtained by regenerative braking (regenerative braking) of the motor generator. In the small deceleration mode, the drive wheels are separated from the power transmission path of the motor generator so that the regenerative braking force by the motor generator is not applied. This makes it easier to drive the vehicle due to inertia, and it is said that good fuel efficiency can be obtained by extending the travel distance while suppressing fuel consumption by the engine. In the low deceleration mode, the regenerative braking force from the motor generator is not applied, so the amount of regenerative power supplied from the motor generator to the power storage device such as a battery is smaller than in the normal deceleration mode.

JP 2007-069787 A

  In a hybrid vehicle, usually, a target charge amount is set with respect to the state of charge (SOC) of the power storage device, and the output of the engine and motor generator and the motor generator are set so that the actual charge amount of the power storage device approaches the target charge amount. Feedback control for adjusting the regenerative power and the like is performed.

  As a result of studies by the present inventor, when such a feedback control is performed, if a travel mode in which the regenerative power amount is made smaller than that in the normal travel mode is frequently executed, the life of the power storage device is reduced as described in detail later. It was found as a new problem that the possibility of.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a vehicle control device that can reduce the possibility of a reduction in the life of the power storage device when the actual charge amount is controlled based on the target charge amount of the power storage device. Is to provide.

  In order to solve the above-described problems, a vehicle control device according to an aspect of the present invention includes an internal combustion engine, a power storage device that can be charged using an output of the internal combustion engine, and a traveling drive that can exchange power between the power storage devices. A vehicle control device used in a vehicle including a motor generator as a source, based on target setting means for setting a target charge amount of the power storage device, based on an actual charge amount of the power storage device and the target charge amount And a travel control means for controlling the internal combustion engine and the motor generator, wherein the travel control means controls the regenerative power to be supplied from the motor generator to the power storage device during travel in an accelerator-off state. And a second travel mode for controlling the regenerative electric energy supplied from the motor generator to the power storage device to be smaller than the first travel mode. Is capable of executing a de, the target setting unit, when the execution frequency of the second traveling mode is high, and sets, as the target charge amount increases as compared with otherwise.

  During execution of the second travel mode, it is difficult to supply sufficient regenerative power to the power storage device by the motor generator, and the actual charge amount of the power storage device is difficult to increase. Therefore, when the second running mode is frequently executed, undershoot is easily performed so that the actual charge amount is lower than the target charge amount when the actual charge amount of the power storage device is controlled to approach the target charge amount. If the vehicle travels while being affected by the undershoot, the actual charge amount is likely to be reduced more than when the execution frequency of the second travel mode is low. As a result, when a large amount of power is consumed during traveling under the influence of undershoot, the possibility that the power storage device is discharged excessively is higher than when the second traveling mode is not frequently executed.

  In this regard, according to this aspect, when the execution frequency of the second traveling mode is high, the target charge amount is set to be larger than that when it is not. Therefore, even if the vehicle travels under the influence of the above-described undershoot, the actual charge amount of the power storage device increases compared to when the same target charge amount is set regardless of whether or not the second travel mode is executed. It becomes easy to become a state. As a result, even when a large amount of power is consumed during traveling under the influence of undershoot, the possibility that the power storage device is excessively discharged can be suppressed, and the possibility of a reduction in the life of the power storage device can be reduced.

  ADVANTAGE OF THE INVENTION According to this invention, when controlling real charge amount based on the target charge amount of an electrical storage apparatus, the vehicle control apparatus which can reduce the possibility of the lifetime reduction of an electrical storage apparatus can be provided.

It is a lineblock diagram showing roughly the vehicles for which a vehicle control device is used. It is a block diagram which shows the functional block of ECU. In 1st Embodiment, it is a figure which shows the change of the actual charge amount when a different target charge amount is set in the previous section of the downhill section. In 1st Embodiment, it is a figure which shows the change of the actual charge amount when the execution pattern of free-running driving mode differs. In 1st Embodiment, it is a figure which shows the change of the actual charge amount at the time of setting a different target charge amount according to the execution frequency of free-running travel mode. It is a flowchart which shows the setting method of the target charge amount which concerns on 1st Embodiment. In 2nd Embodiment, it is a figure which shows the change of the actual charge amount when a different target charge amount is set in the front section of a traffic jam section. In 2nd Embodiment, it is a figure which shows the change of the actual charge amount when the execution pattern of free-running driving mode differs. In 2nd Embodiment, it is a figure which shows the change of the actual charge amount at the time of setting different target charge amount according to the execution frequency of free-running travel mode. It is a flowchart which shows the setting method of the target charge amount which concerns on 2nd Embodiment.

[First Embodiment]
FIG. 1 is a configuration diagram schematically illustrating a vehicle 100 in which the vehicle control device 10 according to the first embodiment is used.
The vehicle 100 includes an engine 104 serving as a first traveling drive source, a first motor generator 106 (hereinafter referred to as a first MG 106) that can generate electric power by the output of the engine 104, a battery 108 that can be charged by electric power generation by the first MG 106, a battery A second motor generator 110 (hereinafter referred to as a second MG 110) serving as a second travel drive source capable of exchanging electric power with the power source 108. Here, the travel drive source refers to a power source that mechanically transmits power to the drive wheels 102 of the vehicle 100 to cause the vehicle 100 to travel. Vehicle 100 is a series-parallel hybrid vehicle that travels by driving either one or both of engine 104 and second MG 110.

  The vehicle 100 further includes a vehicle control device 10 that controls the vehicle 100. The vehicle control apparatus 10 is an electronic control unit (ECU) that comprehensively controls the entire drive system such as the engine 104 and the MGs 106 and 110. Hereinafter, the vehicle control device 10 is referred to as an ECU 10.

  The engine 104 is an internal combustion engine such as a gasoline engine or a diesel engine. The engine 104 is controlled by the ECU 10 and outputs power by driving according to the control.

  Each of first MG 106 and second MG 110 is a rotating electrical machine such as a three-phase synchronous rotating electrical machine. In the series-parallel hybrid vehicle, the second MG 110 serves as an electric motor that outputs power by being driven by power supplied from the battery 108 and also serves as a generator that supplies regenerative power to the battery 108. The first MG 106 receives the power transmitted from the engine 104 through a power transmission mechanism 111 described later and generates power.

  The battery 108 is a power storage device serving as a rechargeable DC power source such as a nickel metal hydride battery or a lithium ion battery. A battery sensor (not shown) for detecting the actual charge amount of the battery 108 is connected to the battery 108. The amount of charge of the battery 108 is expressed by a numerical value based on the fully charged state, for example, a ratio (0 to 100%) of the current amount of charge to the full charge capacity. The battery sensor is, for example, a current sensor, detects a charge / discharge current that is a current when the battery 108 is charged or discharged, and outputs the detected value to the ECU 10. The ECU 10 calculates the actual charge amount of the battery 108 by integrating the detected values of the charge / discharge current of the battery 108 output from the battery sensor.

  The engine 104 and the second MG 110 are connected to the drive wheel 102 via the power transmission mechanism 111. The power transmission mechanism 111 divides and transmits the power of the engine 104 at a variable distribution ratio to the first MG 106 and the drive wheel 102, and a power transmission destination from the power split mechanism 112 to the drive wheel 102 side. Output shaft 114, and an axle 118 coupled to output shaft 114 via reduction mechanism 116. The power split mechanism 112 is, for example, a single pinion type planetary gear mechanism. The distribution ratio of power split mechanism 112 is changed according to control by ECU 10. The output shaft 114 is connected to the rotation shaft of the second MG 110, and the axle 118 is connected to the drive wheels 102.

  Vehicle 100 further includes a power conversion device 120 that supplies power supplied from battery 108 to second MG 110 for driving, and supplies power generated by regenerative braking of second MG 110 to battery 108 for charging. The power conversion device 120 is, for example, an inverter device. The power conversion device 120 converts the DC power of the battery 108 into AC power and supplies it to the second MG 110, converts the regenerative AC power generated in the second MG 110 into DC power and supplies it to the battery 108. The power conversion device 120 adjusts the power exchanged between the battery 108 and the second MG 110 under the control of the ECU 10 to control the power output from the second MG 110 or from the second MG 110 to the battery 108. The regenerative power supplied to is controlled. It is noted that power conversion device 120 exhibits the same function with first MG 106.

  The vehicle 100 further includes a navigation device 122 for supporting traveling toward the destination of the host vehicle. Although not shown, the navigation device 122 is a GPS (Global Positioning System) that measures the current location information of the vehicle, a map database that stores map information, a vehicle information and communication system (VICS) (registered trademark), and the like. Is mainly provided with a receiving unit for receiving the information and an operation unit operated to input destination information. The traffic information includes information indicating a traffic jam condition, a traffic jam distance, and the like on a road around the host vehicle.

  The navigation device 122 executes a predetermined search algorithm using the current location information, map information, and destination information acquired using GPS or the like, and determines a planned travel route that is a planned travel route from the current location to the destination. Explore. As the search algorithm, a known algorithm may be used. For example, the search algorithm having the shortest travel distance among a plurality of travel routes from the current location to the destination may be searched.

  The navigation device 122 outputs travel route information, which is information related to the travel route of the host vehicle, to the ECU 10. The travel route information includes information indicating the planned travel route acquired by executing the search algorithm described above. In addition, information indicating the presence / absence and distance of a downhill section on the planned travel route and the presence / absence and distance of a traffic jam section on the planned travel route is included. Here, the downhill section refers to a section having a slope that is downwardly inclined toward the traveling direction of the host vehicle. The presence / absence and distance of the downhill section is obtained by reading the map information from the map database, and the presence / absence and distance of the traffic jam section is obtained by receiving the traffic information.

  Vehicle 100 further includes an accelerator pedal sensor 124 for detecting the operation amount of the accelerator pedal, and a brake pedal sensor 126 for detecting the operation amount of the brake pedal. The accelerator pedal is operated for the driver to input his intention to accelerate, and the brake pedal is operated for the driver to input his intention to decelerate. Each pedal sensor is a position sensor or the like, and the detected value is output to the ECU 10.

  FIG. 2 is a configuration diagram illustrating functional blocks of the ECU 10. The ECU 10 includes a CPU, a memory, and the like. The ECU 10 includes a target setting unit 12, a travel control unit 14, a specific section detection unit 16, and an index value acquisition unit 18.

  The target setting unit 12 sets a target charge amount that is a control target for the charge amount of the battery 108. Details of the target charge amount setting method will be described later.

  The traveling control unit 14 executes an EV mode and an HV mode as the basic traveling mode of the vehicle. In the EV mode, the first MG 106 is not generated using the power of the engine 104, and the vehicle is driven using the second MG 110 as a driving source. In the HV mode, the vehicle is driven using one or both of the engine 104 and the second MG 110 as a driving source. The traveling control unit 14 selects the EV mode on the assumption that a predetermined EV mode start condition is satisfied. The EV mode start condition is, for example, a case where traveling in a low vehicle speed range where the fuel efficiency of the engine 104 is poor is started. The traveling control unit 14 switches to the HV mode when the actual charge amount of the battery 108 reaches an allowable lower limit value described later during execution of the EV mode.

  The travel control unit 14 controls the operation of the engine 104, the first MG 106, and the second MG 110 so that the actual charge amount of the battery 108 is within the allowable range in the HV mode. This allowable range is set in advance as a range having an allowable upper limit value and an allowable lower limit value so that the actual charge amount of the battery 108 falls within the overcharge region and the overdischarge region. The allowable range is for preventing the battery 108 from entering an overcharged state or an overdischarged state due to further progress of charging or discharging.

  When the actual charge amount of the battery 108 reaches the allowable lower limit value, the travel control unit 14 prohibits the discharge of the battery 108 and controls the operation of the engine 104 and the like so as to charge the battery 108. At this time, for example, the traveling control unit 14 generates the first MG 106 with the power of the engine 104 while traveling using the power of the engine 104 until the actual charge amount of the battery 108 exceeds a predetermined threshold value. Forced charging for supplying power to 108 is executed. Further, the traveling control unit 14 controls the operation of the engine 104 and the like so as to prohibit charging of the battery 108 when the actual charging amount of the battery 108 reaches the allowable upper limit value while the vehicle 100 is traveling. At this time, for example, traveling control unit 14 executes EV traveling mode in which traveling is performed by second MG 110 without stopping engine 104 to generate first MG 106.

  In addition, in the HV mode, travel control unit 14 performs feedback control that controls the operation of engine 104, first MG 106, and second MG 110 so that the actual charge amount of battery 108 approaches the target charge amount. For example, when the accelerator pedal is depressed, traveling control unit 14 determines the target output of one or both of engine 104 and second MG 110 so that the actual charge amount of battery 108 approaches the target charge amount. At this time, the target output is determined using a predetermined map or a relational expression based on the required output determined according to the operation amount of the accelerator pedal, the actual charge amount and target charge amount of the battery 108, the vehicle speed of the vehicle, and the like. . The traveling control unit 14 controls one or both of the engine 104 and the second MG 110 so as to obtain the determined target output, thereby bringing the actual charge amount of the battery 108 close to the target charge amount. In the feedback control according to the present embodiment, proportional control is executed so that the absolute value of the target output of the engine 104 or the like increases as the deviation of the target charge amount from the actual charge amount of the battery 108 increases.

  Here, the traveling control unit 14 executes the inertia traveling mode when the accelerator pedal is not depressed (accelerator off state) and the brake pedal is not depressed (brake off state) while the vehicle 100 is traveling. The inertia traveling mode is a mode in which the vehicle 100 is driven by inertia while fuel supply to the engine 104 is stopped. The inertia traveling mode is selected by determining that the driver does not operate the accelerator pedal or the brake pedal and indicates that the driver intends to inertia.

  In the inertial running mode, the regenerative running mode (first running mode) for controlling the regenerative power to be supplied from the second MG 110 to the battery 108 and the regenerative power supplied from the second MG 110 to the battery 108 are substantially zero. And a free-running traveling mode (second traveling mode) to be controlled. In the regenerative travel mode, a predetermined regenerative braking force corresponding to engine braking is applied to the drive wheels 102 by the second MG 110, and regenerative electric power having a magnitude corresponding to the regenerative braking force is supplied to the battery 108. In the free-run travel mode, the regenerative braking force applied to the drive wheels 102 by the second MG 110 is substantially zero. In the free-run travel mode, the regenerative braking force applied to the drive wheels 102 can be reduced as compared with the regenerative travel mode. Therefore, good fuel efficiency can be obtained by extending the travel distance while suppressing fuel consumption by the engine.

  The regenerative travel mode and the free run travel mode are selected according to a predetermined mode selection condition. The mode selection condition is set, for example, as an operation member such as a shift lever or a switch being at a predetermined position. In this case, either the regenerative travel mode or the free-run travel mode is arbitrarily selected by an operation by the driver. In addition to this, the mode selection condition may be determined in association with the travel route on which the vehicle is traveling. In the present embodiment, when the host vehicle is traveling in a horizontal section, the free-run traveling mode is selected to extend the traveling distance by reducing the regenerative braking force by the second MG 110. On the other hand, when the host vehicle is traveling in a downhill section, a regenerative travel mode in which a regenerative braking force corresponding to an engine brake is applied is selected to prevent unintended acceleration by the driver. The mode selection condition is not limited to this, and may be set according to various conditions.

  The specific section detection unit 16 detects a predetermined specific section as a section in which the actual charge amount of the battery 108 may reach the allowable upper limit value or the allowable lower limit value on the planned travel route from the current location of the host vehicle. In the present embodiment, one of the specific sections is a downhill section. The downhill section is designated as a specific section because in the downhill section, the regenerative braking force is generated by the second MG 110 by executing the regenerative travel mode or operating the brake pedal, and the regenerative power is supplied to the battery 108 by the power generation of the second MG 110, This is because the actual charge amount of the battery 108 may reach the allowable upper limit value. The detection of the downhill section is performed using the travel route information acquired from the navigation device 122. For example, it is performed by determining whether or not there is a downward gradient section within a pre-reading distance that is a predetermined distance from the current location on the planned traveling route of the host vehicle.

  The index value acquisition unit 18 acquires an index value representing the execution frequency of the driver's free-run traveling mode. This index value is an index indicating whether or not the execution frequency of the free-run traveling mode is high. The index value is calculated by learning from the driver's past driving history. For example, the number of executions of the free-run traveling mode in a predetermined learning section is measured and stored as a sample value, and an average value of all sample values stored within a predetermined period is calculated as an index value. The learning interval here is an interval set for generating sample values. The learning section according to the present embodiment is predetermined backward from the start position of the downhill section Ia in order to acquire an index value that accurately reflects the driver's habit in the previous section Ib (described later) of the downhill section Ia. Set as a section within the distance.

Next, a method for setting the target charge amount of the battery 108 will be described in detail.
FIG. 3 is a diagram showing a change in the actual charge amount of the battery 108 when there is a downhill section Ia on the travel route of the host vehicle and a different target charge amount is set in the preceding section Ib of the downhill section Ia. 3A shows the relationship between the travel route of the host vehicle and the altitude, and FIG. 3B shows the relationship between the actual charge amount of the battery 108 and the target charge amount on the travel route. In FIG. 3B, the target charge amount is indicated by a bold line, the actual charge amount is indicated by a thin line, and the allowable upper limit SOCmax and the allowable lower limit SOCmin are also shown. In this example, a situation is considered in which regenerative braking force is applied by executing the regenerative travel mode or operating the brake pedal in the downhill section Ia.

  First, in the preceding section Ib of the downhill section Ia, the case where the free-run traveling mode is not executed and the target charge amount of the battery 108 is entered from the set value V0 up to that time into the downhill section Ia. Suppose. Here, the preceding section Ib is a section immediately before the downhill section Ia. The set value V0 is a target charge amount that is set when the vehicle travels in a section Ic immediately before the previous section Ib. In this case, depending on the magnitude of the set value V0, the actual charge amount may reach the allowable upper limit SOCmax early due to the regenerative braking of the second MG 110, and regenerative power may be lost (see range Ra).

As a countermeasure, the target setting unit 12 sets a target charge amount by prefetching a change in the actual charge amount of the battery 108 in the downhill section Ia. Specifically, the specific section detection unit 16 described above detects whether or not there is a downhill section Ia within the look-ahead distance on the planned travel route of the host vehicle. When it is detected that there is a downhill section Ia within the read-ahead distance, the target setting unit 12 does not cause regenerative power to be lost in the downhill section Ia as the target charge amount in the previous section Ib of the downhill section Ia. Then, a first correction value V1 is set by subtracting a predetermined amount α from the setting value V0. A thin line L _{V1 | FRoff} indicates a change in the actual charge amount when the first correction value V1 is set. By setting the first correction value V1 lower than the set value V0, it is possible to enter the downhill section Ia with the actual charge amount lowered (see the range Rb). As a result, in the downhill section Ia, the amount of regenerative power supplied by the second MG 110 can be increased, and the loss of regenerative power can be suppressed.

Next, it is assumed that the free-run traveling mode is executed and not executed in the previous section Ib. FIG. 4 is a diagram showing changes in the actual charge amount in these cases. Thin lines _{L V1 | FRoff} is thin line _{L V1} in FIG. 3 _| Like the _FRoff, shows a case where the free-run traveling mode is not executed. A thin line L _{V1 | FRon} indicates a case where the free-run traveling mode is executed at the position P in FIG. In this figure, it is assumed that the same first correction value V1 is set as the target charge amount in the previous section Ib regardless of whether or not the free-run travel mode is executed.

  During execution of the free-running driving mode, the regenerative braking force by the second MG 110 is reduced compared to executing the regenerative driving mode or when the brake pedal is depressed, and it becomes difficult to supply sufficient regenerative power to the battery 108. The actual charge amount of the battery 108 is difficult to increase. Therefore, when the free-run travel mode is frequently executed in the previous section Ib, when feedback control is performed so that the actual charge amount of the battery 108 is close to the target charge amount, the actual charge amount is less than the target charge amount. Shooting is easy (see range Rc). If the vehicle travels in the downhill section Ia and the rear section Id while being affected by the undershoot, the actual charge amount is more likely to decrease than when the free-run traveling mode is not frequently executed. As a result, when the power of the battery 108 is largely consumed for some reason during the traveling of the rear section Id under the influence of the undershoot, the battery is run more frequently than when the free-run traveling mode is not executed frequently. The possibility that 108 will be discharged excessively increases (see range Rd). In particular, when the free-run travel mode is frequently executed in the front section Ib, it is highly likely that the driver prefers to execute the free-run travel mode frequently in the rear section Id. The possibility of discharge is further increased. Here, “the battery 108 is discharged excessively” means that the actual charge amount of the battery 108 reaches the allowable lower limit SOCmin in the present embodiment.

As a countermeasure, the target setting unit 12 sets a different target charge amount according to the execution frequency of the free-run travel mode. FIG. 5 is a diagram for explaining this concept. Thin lines _{L V1 | Fron} is thin line _{L V1} in FIG. 4 _| shows a change in the actual amount of charge in _Fron and similar conditions, or without the execution of the free-run drive mode in the previous section Ib, front section Ib Shows the change when the same first correction value V1 is set as the target charge amount. On the other hand, the thin line L _{V2 | FRon} is a second correction value V2 that is larger than the first correction value V1 as the target charge amount of the previous section Ib when frequent execution of the free-run traveling mode in the previous section Ib is predicted. Changes in the actual charge amount when is set.

  If the free-running travel mode is frequently executed in the previous section Ib, if the second correction value V2 larger than the first correction value V1 is predicted and the same target is set, the same target can be obtained. It is possible to enter the downhill section Ia with a higher actual charge amount than when the charge amount (V1) is set (see range Re). As a result, even if the vehicle travels in the downhill section Ia and the rear section Id while being affected by the above-described undershoot, the same target charge amount is set regardless of whether or not the free-run traveling mode is executed. The actual charge amount of the battery 108 tends to increase. As a result, the possibility of excessive discharge of the battery 108 can be suppressed even when the power of the battery 108 is largely consumed during the travel of the rear section Id under the influence of the undershoot (see range Rf). The possibility of a decrease in the life of the battery 108 can be reduced.

  As described above, if frequent execution of the free-run traveling mode in the previous section Ib is predicted, if the second correction value V2 larger than the first correction value V1 set as the target charge amount can be set otherwise, the second correction value V2 can be set. The possibility of a decrease in the life of the battery 108 can be reduced. Therefore, the vehicle control device 10 makes a determination using an index value that represents the frequency of execution of the free-run travel mode by the driver in order to predict whether or not the free-run travel mode is frequently executed in the previous section Ib. . This determination is performed using a reference value set in advance as a reference for determining whether or not the execution frequency of the free-running travel mode is high, and the index value acquired by the index value acquisition unit 18. When the index value is the number of executions of the free-run travel mode in the learning section, the reference value is determined as the number of executions in the learning section being a predetermined number (for example, three times).

  This determination is made by determining whether the index value is less than or equal to the reference value. The case where the index value is equal to or less than the reference value is a case where it is determined that the execution frequency of the free-run traveling mode is not high. That is, it is a case where the execution frequency of the free-running travel mode is low or the free-running travel mode is not executed. On the other hand, the case where the index value exceeds the reference value is a case where it is determined that the execution frequency of the free-run traveling mode is high. If the execution frequency of the free-running driving mode is not high, it can be predicted that the free-running driving mode is not frequently or not executed in the previous section Ib. Therefore, the target setting unit 12 increases the supply amount of the regenerative power. The first correction value V1 is set as the target charge amount. On the other hand, when the execution frequency of the free-running travel mode is high, it can be predicted that the free-running travel mode is frequently executed in the previous section Ib. Therefore, in order to reduce the possibility of a decrease in the life of the battery 108, the first correction value V1 A larger second correction value V2 is set. Note that the second correction value V2 is the set value up to that time so as to suppress the actual charge amount of the battery 108 from reaching the allowable upper limit value early in the downhill section Ia, similarly to the first correction value V1. It is set as a value subtracted from V0.

  The first correction value V1 is set by subtracting a first predetermined amount α (for example, 5%) from the set value V0, and the second correction value V2 is obtained by subtracting the first predetermined amount α from the set value V0. A value obtained by adding the second predetermined amount β (for example, 3%) is set. These predetermined amounts α and β may be defined as fixed values or variable values.

FIG. 6 is a flowchart showing a target charge amount setting method according to the first embodiment.
Based on the travel route information acquired from the navigation device 122, the specific section detection unit 16 is within the read-ahead distance in the planned travel route of the host vehicle, and the actual charge amount of the battery 108 may reach the allowable upper limit value. The downhill section Ia is detected as the specific section (S10). When the downhill section Ia is not detected within the look-ahead distance (N in S10), the target setting unit 12 considers that there is no need to change from the target charge amount, and maintains the target charge amount with the previous set value V0. (S12).

  When the downhill section Ia is detected within the read-ahead distance (Y in S10), the index value acquisition unit 18 predicts whether or not the free-run travel mode is frequently executed in the previous section Ib. A value is acquired, and it is determined whether or not the acquired index value exceeds a reference value (S14). When acquiring the index value, the index value acquisition unit 18 may acquire the index value by reading the index value stored in advance in the storage unit or by calculating the index value at the timing of executing step S14. May be.

  When the index value is equal to or less than the reference value (N in S14), that is, when it is determined that the execution frequency of the free-running travel mode is not high, the target setting unit 12 sets the target charge of the preceding section Ib of the downhill section Ia. For the amount, a first correction value V1 subtracted from the previous set value V0 is set (S16). On the other hand, when the index value exceeds the reference value (Y in S14), that is, when it is determined that the execution frequency of the free-running travel mode is high, the target setting unit 12 sets the target charge amount for the previous section Ib. The second correction value V2 that is higher than the first correction value V1 is set (S18).

  According to the vehicle control device 10 described above, when the actual charge amount is controlled based on the target charge amount of the battery 108, the possibility of a decrease in the life of the battery 108 can be reduced. In particular, when the target charge amount is set by pre-reading the change in the actual charge amount of the battery 108, there is a possibility that the actual charge amount of the battery 108 will reach the allowable lower limit SOCmin in the rear section Id of the downhill section Ia. It can be suppressed. Therefore, better fuel efficiency can be obtained by preventing the forced charging of the battery 108 from being frequently performed under conditions where the fuel efficiency of the engine 104 is poor.

[Second Embodiment]
FIG. 7 is a diagram illustrating a change in the actual charge amount when the traffic route of the host vehicle has a traffic congestion section Ie and a different target charge amount is set in the previous section Ib of the traffic congestion section Ie. In this example, consider a situation in which the EV mode is executed due to being forced to travel in a low vehicle speed range in the traffic jam section Ie.

  First, a case is assumed in which the free-run travel mode is not executed in the previous section Ib of the traffic jam section Ie and the target charge amount of the battery 108 is entered into the traffic jam section Ie without changing from the set value V0 so far. . In this case, depending on the magnitude of the set value V0, the actual charge amount reaches the allowable lower limit SOCmin early by EV traveling (see range Rh), and the forced charging of the battery 108 is a low vehicle speed range where the fuel efficiency of the engine 104 is poor. There is a possibility that the fuel consumption will be reduced.

As a countermeasure, the target setting unit 12 sets a target charge amount by prefetching a change in the actual charge amount of the battery 108 in the traffic jam section Ie. Specifically, the specific section detection unit 16 detects whether or not there is a traffic jam section Ie within the look-ahead distance on the planned travel route of the host vehicle. When it is detected that there is a traffic jam section Ie within the look-ahead distance, the target setting unit 12 sets the set value V0 as the target charge amount in the previous section Ib of the traffic jam section Ie so as not to cause forced charging in the traffic jam section Ie. Is set to a first correction value V1. A thin line L _{V1 | FRoff} indicates a change in the actual charge amount when the first correction value V1 is set. By setting the first correction value V1 higher than the set value V0, it is possible to enter the traffic congestion section Ie with the actual charge amount increased (see the range Ri). As a result, it is possible to prevent the actual charge amount from reaching the allowable lower limit SOCmin due to the EV traveling in the traffic jam section Ie.

Next, it is assumed that the free-run traveling mode is executed and not executed in the previous section Ib. FIG. 8 is a diagram showing changes in the actual charge amount in these cases. A thin line L _{V1 | FRoff} indicates a case where the free-run traveling mode is not executed, like the thin line _{V1 | FRoff of} FIG. A thin line L _{V1 | FRon} indicates a case where the free-run traveling mode is executed at the position P in FIG. In this figure, it is assumed that the same first correction value V1 is set as the target charge amount in the previous section Ib regardless of whether or not the free-run travel mode is executed.

  For the same reason as in the first embodiment, when the free-run traveling mode is frequently executed in the previous section Ib, when the feedback control is performed so that the actual charge amount of the battery 108 approaches the target charge amount, the actual charge amount is It becomes easy to undershoot to fall below the target charge amount (see range Rj). If the vehicle travels in the traffic jam section Ie while being affected by the undershoot, the actual charge amount is more likely to decrease than when the free-run travel mode is not frequently executed. As a result, in the middle of traveling in the traffic jam section Ie under the influence of the undershoot, there is an increased possibility that the battery 108 is excessively discharged when the power of the battery 108 is largely consumed by EV traveling ( Range Rk).

As a countermeasure, the target setting unit 12 sets a different target charge amount according to the execution frequency of the free-running travel mode, as in the first embodiment. FIG. 9 is a diagram for explaining this concept. Thin lines _{L V1 | Fron} is thin line _{L V1} in FIG. 8 _| shows the change of the actual amount of charge under the same conditions as _Fron, regardless of the frequency of execution of the free-run drive mode in the previous section Ib, before the section Ib A change when the same first correction value V1 is set as the target charge amount is shown. On the other hand, the thin line L _{V2 | FRon} is a second correction value V2 that is larger than the first correction value V1 as the target charge amount of the previous section Ib when frequent execution of the free-run traveling mode in the previous section Ib is predicted. Changes in the actual charge amount when is set.

  When the free-running travel mode is frequently executed in the previous section Ib, as in the first embodiment, if this is predicted and the second correction value V2 larger than the first correction value V1 is set, the execution is executed. It is possible to enter the traffic jam section Ie with a higher actual charge amount than when setting the same target charge amount (V1) regardless of whether or not there is (see range Rl). As a result, even if the vehicle travels in the traffic jam section Ie while being affected by the above-described undershoot, the actual performance of the battery 108 is greater than when the same target charge amount is set regardless of whether or not the free-run travel mode is executed. It becomes easy to be in the state where the amount of charge increased. As a result, the possibility of excessive discharge of the battery 108 can be suppressed even when the power of the battery 108 is largely consumed during traveling in the traffic jam section Ie under the influence of the undershoot (see range Rm). The possibility of a decrease in the life of the battery 108 can be reduced.

  As described above, as in the first embodiment, when frequent execution of the free-run traveling mode in the previous section Ib is predicted, the first correction value V1 that is set as the target charge amount otherwise is set. If the 2 correction value V2 can be set, the possibility that the life of the battery 108 may be reduced can be reduced. Therefore, in order to predict whether or not the free-run travel mode is executed in the previous section Ib, the vehicle control device 10 uses an index value indicating the frequency of execution of the driver's free-run travel mode as in the first embodiment. Make the judgment used.

  Since most of the determination is the same as in the first embodiment, only the difference will be described. When the above-described index value is equal to or less than the reference value, that is, when it is determined that the execution frequency of the free-running travel mode is not high, it can be predicted that the free-running travel mode is not frequently or not executed in the previous section Ib. Therefore, the target setting unit 12 sets the first correction value V1 as the target charge amount of the previous section Ib in order to suppress a large change from the set value V0 of the target charge amount in the previous section Ib. On the other hand, when the index value exceeds the reference value, that is, when it is determined that the execution frequency of the free-running driving mode is high, it can be predicted that the free-running driving mode is frequently executed in the previous section Ib. In order to reduce the possibility of a decrease in the service life, a second correction value V2 larger than the first correction value V1 is set. Note that the second correction value V2 is the set value V0 up to that time so as to suppress the actual charge amount of the battery 108 from reaching the allowable lower limit early in the traffic jam section Ie, similarly to the first correction value V1. It is set as a value added more.

  The first correction value V1 is set to a value obtained by adding a first predetermined amount γ (for example, 5%) to the set value V0, and the second correction value V2 is obtained by adding the first predetermined value γ to the set value V0. A value obtained by adding the second predetermined amount δ (for example, 3%) is set. These predetermined amounts γ and δ may be determined as fixed values or variable values.

FIG. 10 is a flowchart showing a target charge amount setting method according to the second embodiment.
Based on the travel route information acquired from the navigation device 122, the specific section detection unit 16 is within the read-ahead distance in the planned travel route of the host vehicle, and the actual charge amount of the battery 108 may reach the allowable lower limit value. A traffic jam section Ie is detected as a specific section (S30). When the traffic jam section Ie is not detected within the pre-read distance (N in S30), the target setting unit 12 considers that there is no need to change the target charge amount, and maintains the target charge amount with the previous set value V0. (S32).

  When the traffic jam section Ie is detected within the pre-read distance (Y in S30), the index value acquisition unit 18 acquires the index value in order to predict whether or not the free-run travel mode is frequently executed in the previous section Ib. Then, it is determined whether or not the acquired index value exceeds the reference value (S34). Unlike the first embodiment, the index value acquisition unit 18 acquires an index value that accurately reflects the driver's habit in the previous section Ib of the traffic jam section Ie, so that the index value acquisition section 18 moves backward from the start position of the traffic jam section Ie. An index value is calculated using a section within a predetermined distance as a learning section.

  When the index value is equal to or less than the reference value (N in S34), that is, when it is determined that the execution frequency of the free-running travel mode is not high, the target setting unit 12 sets the target charge amount of the previous section Ib of the traffic jam section Ie. Is set to the first correction value V1 added from the previous setting value V0 (S36). On the other hand, when the index value exceeds the reference value (Y in S34), that is, when it is determined that the execution frequency of the free-running driving mode is high, the target setting unit 12 sets the target charging of the previous section Ib of the traffic jam section Ie. The amount is added from the set value V0 so far, and the second correction value V2 higher than the first correction value V0 is set (S38).

  According to the vehicle control device 10 described above, when the actual charge amount is controlled based on the target charge amount of the battery 108, the possibility of a decrease in the life of the battery 108 can be reduced. In particular, when the target charge amount is set by pre-reading the change in the actual charge amount of the battery 108, the possibility that the actual charge amount of the battery 108 reaches the allowable lower limit SOCmin in the traffic jam section Ie can be suppressed. Therefore, better fuel efficiency can be obtained by preventing the forced charging of the battery 108 from being frequently performed under conditions where the fuel efficiency of the engine 104 is poor.

  In the above, this invention was demonstrated based on the Example. The embodiments are merely examples, and it will be understood by those skilled in the art that various modifications can be made to the combination of each component and each processing process, and such modifications are within the scope of the present invention.

  Although the vehicle 100 has been described as a series-parallel hybrid vehicle, it may be a hybrid vehicle of another type such as a series type or a parallel type. Although the battery 108 has been described as an example of the power storage device, the power storage device may be a capacitor or the like.

  The free-run travel mode has been described as an example of the second travel mode in which the regenerative power supplied from the second MG 110 to the battery 108 is controlled to be smaller than the regenerative travel mode (first travel mode). In the second traveling mode, it is sufficient that the amount of regenerative power supplied from the second MG 110 to the battery 108 is smaller than that in the regenerative traveling mode, and the second traveling mode may not be controlled to be substantially zero.

  Although the index value has been described as an example in which the number of executions of the free-running travel mode in the predetermined learning section is a sample value, the execution distance of the free-running travel mode in the predetermined learning section may be used as the sample value. . In addition, the index value is stored as a measurement value of the number of executions and execution distance of the free-run travel mode in the period from when the ignition is turned on to the present, and the value obtained by dividing the measurement value by the total travel distance during the same period is used. May be.

  Further, the example in which the above-described prefetch distance (see S10 in FIG. 5, S30 in FIG. 8, and the like) is a fixed value has been described, but the difference value between the first correction value V1 or the second correction value V2 with respect to the set value V0 is large. It is good also as a variable value which changes according to length. For example, the larger the difference value between the first correction value V1 or the second correction value V2 with respect to the set value V0, the longer it takes for the actual charge amount of the battery 108 to approach the correction values V1 and V2. Therefore, by setting the size of the prefetch distance according to the difference value so that the prefetch distance increases as the difference value increases, the actual charge amount of the battery 108 is brought close to the target charge amount in a specific section. It becomes easier to enter the start position.

DESCRIPTION OF SYMBOLS 10 ... Vehicle control apparatus, 12 ... Travel control part, 14 ... Target setting part, 16 ... Specific area detection part, 18 ... Index value acquisition part, 100 ... Vehicle, 102 ... Drive wheel, 104 ... Engine (internal combustion engine), 106 ... 1st MG (generator), 108 ... Battery (power storage device), 110 ... 2nd MG (electric motor).

Claims (1)

A vehicle control device used in a vehicle, comprising: an internal combustion engine; a power storage device that can be charged using an output of the internal combustion engine; and a motor generator that serves as a travel drive source capable of exchanging power with the power storage device. There,
Target setting means for setting a target charge amount of the power storage device;
Travel control means for controlling the internal combustion engine and the motor generator based on the actual charge amount of the power storage device and the target charge amount; and
The travel control means includes a first travel mode for controlling regenerative power to be supplied from the motor generator to the power storage device during travel in an accelerator-off state, and a regenerative power supplied from the motor generator to the power storage device. A second traveling mode for controlling the electric energy to be smaller than the first traveling mode, and
The target setting means sets the target charge amount to be larger when the execution frequency of the second traveling mode is high than when it is not.

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