JP2010221745A - Vehicle control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To satisfactorily perform reverse travel on a slope in a vehicle having a vehicle control device for distributing power among an engine, a rotary electric machine for power generating, and a rotary electric machine for traveling. <P>SOLUTION: The vehicle control device 40 in a vehicle control system 8 includes: the engine 28; rotary electric machines 24, 26; and a power distributing mechanism 30, and also includes: a gradient acquiring processing section 42 for acquiring a gradient θ of a vehicle; a shift position acquiring processing section 44 for acquiring a shift position; an SOC acquiring processing section 46 for acquiring an SOC value of a power storage device 12; and an SOC threshold changing processing section 50 for changing and setting a charge start SOC value and a charge end SOC value lower than those in a normal state, respectively, when the shift position is in an R range as a reverse travel range and the gradient θ is not smaller than a predetermined gradient threshold value θ<SB>th</SB>. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a vehicle control device, and more particularly to a vehicle control device in a vehicle that distributes power among an engine, a rotating electric machine for power generation, and a rotating electric machine for traveling.

  In a vehicle in which a rotating electrical machine is mounted together with an engine, power is distributed between the engine and the rotating electrical machine. In this case, power distribution according to various operation states of the vehicle is performed in consideration of improvement in fuel consumption of the entire vehicle including the power storage device included in the power supply circuit connected to the rotating electrical machine.

  As a technique related to the present invention, Patent Document 1 discloses, as a control method for a vehicle including an internal combustion engine capable of fixing an output shaft and two electric motors, in addition to an engine abnormality or the like, the shift position is an R for reverse travel. When the position is equal to or greater than a predetermined gradient, and the SOC, which is the remaining capacity of the battery, is equal to or greater than a threshold value, the engine crankshaft is fixed to run on two motors to satisfy the condition for turning on the clutch. When the conditions for turning on the engine are not satisfied, it is stated that the engine and the two electric motors are controlled to travel.

JP 2008-265598 A

  As described in Patent Document 1, there are various vehicle operating states. For example, power distribution including a power storage device is performed in accordance with the state even in a reverse traveling state on a slope.

  In a reverse drive state on a hill, it is desirable that the vehicle has a suitable travel distance if it is a hill with a certain degree of inclination. In such a case, considering that the rotating electrical machine moves backward on a slope, in order to secure an appropriate travel distance with a certain degree of inclination, the power storage device must be charged to such an extent as to satisfy that condition. is required. If the power storage device does not have a sufficient amount of charge, the engine is started and power is generated.

  By the way, when the engine is started to drive the rotating electrical machine for power generation when the reverse operation is performed with the driving force of the traveling rotating electrical machine, the driving force of the traveling rotary electrical machine is The driving force from the engine is distributed and output to the vehicle axle. At this time, it is sufficient that the driving force distribution by the engine assists the driving force of the rotating electric machine for traveling. However, depending on the power distribution mechanism, the driving force distribution of the engine may travel during reverse driving. It is distributed in the opposite direction with respect to the driving force of the rotating electric machine.

  When the power distribution is performed in this way, the engine is started, so that the driving force on the axle becomes small as compared to when the engine is not started.

  An object of the present invention is to provide a vehicle control device that can sufficiently reverse a slope on a vehicle that distributes power among an engine, a rotating electric machine for power generation, and a rotating electric machine for traveling.

  A vehicle control device according to the present invention is a vehicle control device for a vehicle that distributes power among an engine, a rotating electric machine for power generation, and a rotating electric machine for traveling, and obtains the inclination of the vehicle according to the gradient inclination of the road surface. A degree acquisition means, a shift position acquisition means for acquiring a shift position, an SOC acquisition means for acquiring an SOC value that is a state of charge of a rotating electrical storage device, and an SOC value that falls below a predetermined charge start SOC value A charge / discharge control unit that starts the engine and starts forced charging by the rotating electric machine for power generation, and performs control to end forced charging when it rises above a predetermined charge end SOC value, and the shift position is a reverse range, And a changing means for changing the setting of the charge start SOC value to a lower value than in a normal case when the inclination is equal to or greater than a predetermined inclination threshold.

  In the vehicle control device according to the present invention, it is preferable that the changing means further changes the setting of the charge end SOC value to a value lower than that in a normal case.

  With the above-described configuration, the vehicle control device changes the setting of the charge start SOC value to a lower value than in a normal case when the shift position is in the reverse range and the gradient is equal to or greater than a predetermined gradient threshold. As a result, the start timing of the engine performed for charging the power storage device can be delayed, and the driving force distribution timing to the axle by the engine start can be delayed to extend the traveling distance of the reverse travel on the slope.

  Further, in the vehicle control device, the changing means further changes the setting of the charging end SOC value to a value lower than that in a normal case, so that the forced charging period can be prevented from becoming unnecessarily long.

It is a figure explaining the composition of the vehicle control system to which the vehicle control device of the embodiment concerning the present invention is applied. It is a figure explaining the relationship between SOC value at the time of a reverse slope drive, and a travel continuation distance. In embodiment which concerns on this invention, it is a figure explaining the influence by engine starting in the case of reverse slope. In embodiment which concerns on this invention, it is a collinear diagram for demonstrating the influence by engine starting in the case of reverse slope. It is a flowchart which shows the procedure of the vehicle control in embodiment which concerns on this invention. It is a figure explaining the mode of the setting of the SOC threshold value in FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following, a vehicle in which the engine and the two rotating electrical machines perform power distribution by the power distribution mechanism will be described as an object of the vehicle control system, but the specific configuration is an example, and other components are added. You may do. For example, a speed reduction mechanism may be further provided in the power distribution mechanism. Further, with respect to the power supply circuit connected to the rotating electrical machine, a system main relay, a DC / DC converter, or the like may be added to the configuration described.

  Below, the same code | symbol is attached | subjected to the same element in all the drawings, and the overlapping description is abbreviate | omitted. In the description in the text, the symbols described before are used as necessary.

  FIG. 1 is a diagram showing a configuration of a vehicle control system 8 for a vehicle on which an engine and a rotating electrical machine are mounted. Here, a situation is shown in which the vehicle 6 moves backward on the road surface 4 of the slope with a slope θ, that is, climbs the slope while going backward.

  The vehicle control system 8 includes a drive block 10 for driving the vehicle 6 and a vehicle control device 40 that controls the operation of the components of the drive block as a whole.

  The drive block 10 is roughly divided into a power supply circuit including the power storage device 12, two rotating electrical machines 24 and 26 connected thereto, an engine 28, and power distribution between the rotating electrical machines 24 and 26 and the engine 28. And a power distribution mechanism 30 that outputs a driving force to the axle 32.

  The power supply circuit including the power storage device 12 is a circuit connected to the rotating electrical machines 24 and 26 and supplies power to the rotating electrical machines 24 and 26 when they function as drive motors, or the rotating electrical machines 24 and 26 generate power. When functioning as a battery, it has a function of receiving regenerative power and charging the power storage device 12. The power supply circuit includes a power storage device 12 that is a secondary battery, a smoothing capacitor 14 on the power storage device 12 side, a voltage converter 16, a smoothing capacitor 18 on the inverters 20 and 22 side, and inverters 20 and 22. Is done.

  As the power storage device 12, for example, a lithium ion assembled battery or a nickel hydride assembled battery having a terminal voltage of about 200 V, a capacitor, or the like can be used.

  The voltage converter 16 is a circuit having a function of boosting the voltage on the power storage device 12 side to, for example, about 650 V using the energy storage action of the reactor. The voltage converter 16 has a bidirectional function, and when the electric power from the inverters 20 and 22 side is supplied as charging power to the power storage device 12 side, the high voltage on the inverters 20 and 22 side is a voltage suitable for the power storage device 12. It also has the effect of reducing the pressure.

  The smoothing capacitor 14 on the power storage device 12 side and the smoothing capacitor 18 on the inverters 20 and 22 side have a function of suppressing and smoothing fluctuations in voltage and current on each side.

  The inverters 20 and 22 are circuits that perform power conversion between AC power and DC power. Inverters 20 and 22 are configured to include a plurality of switching elements that operate under the control of vehicle control device 40. One of the two inverter circuits is an MG1 inverter for operating the first rotating electrical machine (MG1) 24, and the other is an MG2 inverter for operating the second rotating electrical machine (MG2) 26.

  When the first rotating electrical machine (MG1) 24 is caused to function as a generator, the MG1 inverter converts AC three-phase regenerative power from the first rotating electrical machine (MG1) 24 into DC power, and charging current is charged to the power storage device side. As an AC / DC converter function. Further, the MG2 inverter 22 for operating the second rotating electrical machine (MG2) 26 converts the DC power from the power storage device side into AC three-phase driving power when the vehicle is in power running, and the second rotating electrical machine (MG2). ) When the vehicle is braked, the AC three-phase regenerative power from the second rotating electrical machine (MG2) 26 is converted into DC power, and the charging current is charged to the power storage device side. And an AC / DC conversion function supplied as

  As described above, the drive source of the vehicle 6 includes the first rotary electric machine (MG1) 24 and the second rotary electric machine (MG2) 26 using the engine 28 and the power storage device 12 as power sources.

  The engine 28 is an internal combustion engine having a plurality of cylinders, and constitutes a drive source for the vehicle together with the first rotating electrical machine 24 and the second rotating electrical machine 26. The engine 28 drives the axle 32, which is the drive shaft of the vehicle, via the power distribution mechanism 30 and the like, and has the function of causing the vehicle to travel and causing the first rotating electrical machine 24 to be used as a generator to generate power, The power storage device 12 has a function of charging.

  The two rotating electrical machines 24 and 26 are motor generators (MG) mounted on the vehicle, and basically have the same configuration, and both function as motors when electric power is supplied from the power storage device 12. The three-phase synchronous rotating electric machine can function as a generator when driven by the engine 28 or when the vehicle is braked.

  As the division of roles of the two rotating electric machines 24 and 26, the first rotating electric machine (MG1) 24 can be mainly used as a rotating electric machine for power generation, and the second rotating electric machine (MG2) 26 can be used as a rotating electric machine for traveling. . Thus, the first rotating electrical machine (MG1) 24 is driven by the engine 28 and used as a generator, and the generated electric power is transferred to the power storage device 12 via the MG1 inverter 20 and the voltage converter 16. Used as supply. The second rotating electrical machine (MG2) 26 is used for vehicle travel, and receives AC power supplied from the power storage device 12 during powering and is converted via the voltage converter 16 and the MG2 inverter 22. Functions as a motor to drive the axle 32 which is a drive shaft of the vehicle, functions as a generator at the time of braking, collects regenerative energy, and supplies it to the power storage device 12 via the MG2 inverter 22 and the voltage converter 16 And can.

  The power distribution mechanism 30 has a function of distributing power among the engine 28, the first rotating electrical machine 24, and the second rotating electrical machine 26, and a planetary mechanism can be used. In the example of FIG. 1, two planetary mechanisms are used.

  In the first planetary mechanism, the first planetary mechanism is provided between the engine 28 and the first rotating electrical machine 24, the output shaft of the first rotating electrical machine 24 is connected to the sun gear (S1), and the planetary gears. The output shaft of the engine 28 is connected to the gear carrier (C1). The ring gear (R1) is connected to the axle 32 together with the ring gear (R2) of the next second planetary mechanism.

  In the second planetary mechanism, the output shaft of the second rotating electrical machine 26 is connected to the sun gear (S2), and the carrier (C2) of the planetary gear is set at a fixed position. As described above, the ring gear (R2) is connected to the axle 32 in common with the ring gear (R1) of the first planetary mechanism. The operation of the power distribution mechanism 30 will be described in detail later.

  In FIG. 1, the inclination sensor 34 provided in the vehicle 6 has a function of detecting the inclination θ of the vehicle corresponding to the gradient inclination of the road surface. The detected inclination θ is transmitted to the vehicle control device 40 through an appropriate signal line. For example, an appropriate accelerometer can be used as the inclination sensor 34.

  The shift position detector 36 provided in the vehicle 6 has a function of detecting a shift position that is a shift position of the shift lever. In particular, here, the shift lever has a function of transmitting information regarding whether or not the shift lever is in the R range which is the reverse range to the vehicle control device 40 via an appropriate signal line.

  The SOC calculation unit 38 connected to the power storage device 12 has a function of calculating the SOC value, which is the state of charge of the power storage device 12, from time to time so that the power storage device 12 is not overcharged or overdischarged. Specifically, the current charge amount with respect to the charge capacity of the power storage device 12 is calculated based on the power that enters and exits the power storage device 12 via the voltage converter 16 and the inverters 20 and 22. The SOC value can be indicated by a remaining charge amount that is a ratio of the current charge amount to the charge capacity. The calculated SOC value is transmitted to the vehicle control device 40 via an appropriate signal line.

  The vehicle control device 40 has a function of controlling the operation of each element as a whole. For example, a function for controlling the operation of the engine 28, a function for controlling the operation of the two rotating electric machines 24 and 26, a function for controlling the operation of the voltage converter 16 and the inverters 20 and 22, and an operation of the power distribution mechanism 30 are controlled. A function, a function of controlling charge / discharge of the power storage device 12, and the like.

  Such a vehicle control device 40 can be configured by a control device suitable for mounting a vehicle, for example, a vehicle-mounted computer. Although the vehicle control device 40 can be configured by a single computer, the functions can be shared by a plurality of computers in consideration that the required processing speed varies depending on each component. For example, the function of controlling the operation of the engine 28 is shared by an engine electrical control unit (ECU), and the function of controlling the operations of the two rotating electrical machines 24 and 26 is shared by the MG-ECU. 16, the function of controlling the operation of the inverters 20 and 22 is PCU (Power Control Unit), charging and discharging of the power storage device 12 is shared by the battery ECU, and the whole including these and the power distribution mechanism 30 is controlled by the integrated ECU, etc. It can also be configured.

In FIG. 1, the vehicle control device 40 has, among these functions, a control function that makes the drive sufficiently, particularly when the vehicle 6 is in a reverse drive on a slope. For this purpose, an inclination acquisition processing unit 42 that acquires the inclination θ of the vehicle according to the slope gradient of the road surface, a shift position acquisition processing unit 44 that acquires the shift position, and an SOC value that is the state of charge of the power storage device 12 are acquired. And the SOC acquisition processing unit 46 to start, when the SOC value falls below a predetermined charging start SOC value, the engine is started and forced charging by the rotating electric machine for power generation starts, and when the SOC value rises above the predetermined charging end SOC value The charge / discharge control processing unit 48 that performs control to end the charging, and the charge start SOC value when the shift position is the R range that is the reverse range and the gradient θ is equal to or greater than a predetermined gradient threshold θ _th An SOC threshold value change processing unit 50 is configured to change the setting of the charge end SOC value to a value lower than the normal case.

  These functions can be realized by executing software, and specifically, can be realized by executing the SOC setting part in the vehicle control program. Some of these functions may be realized by hardware.

  The operation of the above configuration, particularly each function of the vehicle control device 40 will be described in detail below. First, the state when the vehicle 6 is in the reverse travel state on the slope will be described with reference to FIGS. 2 to 4, and then the drive will be sufficient when the vehicle 6 is in the reverse travel state on the slope with reference to FIGS. The control function will be described.

FIG. 2 is a diagram for explaining the relationship between the SOC value and the travel distance when the vehicle 6 moves backward on the slope by the second rotating electrical machine 26. In FIG. 2, the horizontal axis represents the SOC value, the vertical axis represents the travel distance, and here, the slope is shown as a parameter. The traveling distance in this case is a traveling distance indicating how long the hill can be climbed with the SOC value at that time in the R range. The travel distance L ₀ is set according to the target specification of the vehicle. As shown in FIG. 2, the SOC value, which is the remaining charge amount of the power storage device 12 for achieving the target specification L ₀ , becomes a larger value as the gradient increases.

In other words, the greater the slope gradient of the hill, the shorter the travel duration if the SOC value is the same. If the travel duration is the target specification L ₀ , the greater the slope θ, the greater the required SOC value. Value. The vehicle control device 40 refers to the characteristic diagram as shown in FIG. 2 and, when the inclination θ is given, obtains the SOC value necessary to achieve the travel duration L ₀ and compares it with the current SOC value.

If the current SOC value is higher than the SOC value required to achieve L ₀ , the electric power is supplied from the power storage device 12 to the second rotating electrical machine 26 as it is, and the backward running of the slope is executed with the driving force of the second rotating electrical machine 26. Let Conversely, when the current SOC value is lower than the SOC value necessary to achieve L ₀ , the engine 28 is started to supply the electric power generated by the first rotating electrical machine 24 to the power storage device 12 and the required SOC. The remaining charge amount is increased to the value.

FIG. 3 is a diagram for explaining the influence of the engine starting when going backward on a slope. The horizontal axis in FIG. 3 is the gradient slope of the road surface 4, which is actually the same as the slope θ that is the detection value of the slope sensor 34 of the vehicle 6. The vertical axis represents the driving force required when climbing the hill on the axle 32. In FIG. 3, the broken line represents the starting driving force 60 required to start climbing that is necessary when the vehicle 6 climbs from a state of stopping on a slope. The solid line is the driving force 62 required for climbing during cruising required when the vehicle 6 is already climbing on a slope and the climbing state is maintained and the climbing is continued. As shown in FIG. 3, if it is the same θ, the driving force 60 required for climbing when starting is the driving force 62 required for climbing when driving
Bigger than.

Driving force of the setting of the second rotary electric machine 26 refers the target specifications of continuous travel distance L ₀ described in FIG 2, and a slope theta ₀ at that time, the driving force of the second rotary electric machine 26 only To achieve this goal. That is, in FIG. 3, the driving force of the second rotating electrical machine 26 is set so as to satisfy the required starting driving force 60 when θ = θ ₀ . In FIG. 3, the driving force at that time is shown as MG2 in the frame. The premise at this time is that sufficient electric power is supplied from the power storage device 12 to the second rotating electrical machine 26.

In FIG. 2, if the current SOC value of the power storage device 12 is lower than the SOC (θ ₀ ), which is the SOC value necessary to achieve the slope θ ₀ and the travel distance L ₀ , as described above. Then, the engine 28 starts. Therefore, the driving force by the second rotating electrical machine 26 and the driving force by which the driving force of the engine 28 is distributed to the ring (R1) by the first planetary mechanism are output to the axle 32.

  At that time, in the power distribution mechanism 30 configured as shown in FIG. 1, the driving force distributed to the ring (R1) by the engine 28 reduces the driving force output to the ring (R2) by the second rotating electrical machine 26. Acts as follows. In FIG. 3, the driving force of the MG2 engine is indicated by a frame, but the value is lower than the driving force of MG2 of the previous frame.

  FIG. 4 is a diagram for explaining the situation using a nomograph. The upper part of FIG. 4 is an alignment chart when the axle 32 is driven only by the driving force of the second rotating electrical machine 26 with the engine 28 not operating, and the lower part further shows the state in the upper part. FIG. 4 is a nomograph when the engine 28 is started and the first rotating electrical machine 24 is generated. In the alignment chart, the vertical axis represents the number of rotations, and the horizontal axis represents the elements of the power distribution mechanism 30 arranged at intervals according to the gear ratio of the respective gears.

  In FIG. 4, the sun gear (S1), the carrier (C2), and the ring (R1) of the first planetary mechanism and the ring (R2), the carrier (C2), and the sun gear (S2) of the second planetary mechanism are in this order. It is shown that they are arranged on the horizontal axis. As described above, R1 and R2 are connected to the axle 32 in common. Since the common shaft on the axle 32 side is called a propeller shaft (P), this is shown in FIG. 4 as P = R1 = R2.

  FIG. 4 is a schematic diagram, and the elements are not arranged on the horizontal axis at the actual gear ratio. As is well known, in such a collinear diagram, the rotational speed relationship between a plurality of elements becomes a straight line when the rotational speed positions of these elements are connected.

  The upper part of FIG. 4 is a collinear diagram when the engine 28 is not started. Here, since the carrier (C2) is in the fixed position in the second planetary mechanism, the relationship between the rotation speed of the second rotating electrical machine 26 of the sun gear (S2) and the rotation speed of the ring (R2) is expressed by the carrier ( When the rotation speed of C2) is 0, the sun gear (S2), the carrier (C2), and the ring (R2) are in a straight line.

Therefore, the torque corresponding to the driving force of the propeller shaft (P) connected to the axle 32 is calculated from the torque _TMG2 of the second rotating electrical machine 26 in the sun gear (S2) and the gear ratio in the first planetary mechanism. is is shown in FIG. 4 as a T _R (MG2). The driving force corresponding to T _R (MG2) is transmitted to the axle 32 as the output of the propeller shaft (P).

The lower part of FIG. 4 shows a case where the engine 28 is started and the first rotating electrical machine 24 is driven on the assumption that the target travel duration L ₀ cannot be achieved with the inclination θ ₀ as described in FIG. FIG. Here, a torque T _E to the output of the engine 28, depending on the gear ratio of the first planetary mechanism, the first rotating electric machine 24 of the sun gear (S1), is distributed to the ring (R2). Here again, in the sun gear (S1), the operation of the first rotating electrical machine 24 is performed so that the power generation torque T _MG1 corresponding to the distributed torque T _S (E) is generated so that the _nomogram is linear. Be controlled.

As shown in the lower part of FIG. 4, the direction of the torque T _R (E) distributed to the ring (R1) is opposite to that of the torque T _R (MG2) output to the previous ring (R2). From this, the torque in the propeller shaft (P) connecting the ring (R1) and the ring (R2) in common is a value smaller than the torque T _R (MG2). That is, when the engine 28 is started for power generation by the first rotating electrical machine 24, only a torque smaller than the torque output to the propeller shaft (P) when not starting is output. That is, the driving force on the axle 32 is reduced.

  As described above, it has been described that the vehicle 6 is in the backward traveling state on the hill, in particular, that when the engine 28 is started for power generation by the first rotating electrical machine 24, the driving force in the axle 32 is reduced. A control function for sufficiently driving the vehicle 6 when the vehicle 6 is in a reverse drive on a hill will be described using FIGS.

  FIG. 5 is a flowchart showing an overall procedure of vehicle control including backward traveling on a slope. Each procedure corresponds to each processing procedure of the SOC setting part of the vehicle control program.

  First, the shift position SP, the inclination θ of the vehicle 6, and the SOC value are acquired (S10). This step is executed by the functions of the shift position acquisition processing unit 44, the inclination acquisition processing unit 42, and the SOC acquisition processing unit 46 of the vehicle control device 40. Specifically, each data transmitted from the shift position detector 36, the inclination sensor 34, and the SOC calculator 38 is acquired.

  It is determined whether or not the data of the acquired shift position SP is in the R range (S12). The R range is a shift position set by the user when the vehicle 6 moves backward. If the determination in S12 is not affirmed, the process returns to S10, and the shift position SP is acquired again after an appropriate sampling time.

If the determination is affirmative in S12, it is determined whether or not the inclination θ is a predetermined inclination threshold θ _th (S14). The inclination threshold value _θth is set based on the specification of the vehicle 6 and the like. For example, θ _th can be set to about 10 to 15 degrees.

  When the determination in S14 is negative, it is determined that the vehicle is in the reverse travel state, and the SOC threshold for forced charging is set as a normal range (S16). The SOC threshold value related to forced charging includes a charging start threshold value and a charging end threshold value. The charge start threshold value is a charge start SOC value when the engine 28 is started and forced charging by the generator rotating electrical machine is started when the SOC value falls below a predetermined charge start SOC value. The charging end threshold is a charging end SOC value when the forced charging is ended when the SOC value rises above a predetermined charging end SOC value.

  The use of a threshold whose threshold value related to forced charging is set in the normal range means that normal driving, that is, including forward driving and the like, the charging start threshold value and the charging end threshold value which are set in advance in the vehicle 6 as standard are used. It is. As a normal range of the SOC threshold value, for example, the charge start threshold value can be 40%, the charge end threshold value can be 50%, and the like. Of course, other ranges may be used as the normal range of the SOC threshold depending on the specifications of the vehicle 6 and the like.

  If the determination in step S14 is affirmative, the degree of inclination is in a reverse drive state, so the SOC threshold value related to forced charging is set to a lower range than the normal range (S18). This setting is exceptional and temporary because the range of the SOC threshold is changed when the determination in S14 is affirmative. This step is executed by the function of the SOC threshold value change processing unit 50 of the vehicle control device 40.

  FIG. 6 shows how the SOC threshold range is changed. In FIG. 6, (a) is the SOC threshold value in the normal state, and the hatched range corresponds to the normal range. Here, as described above, the charging start threshold is 40%, and the charging end threshold is 50%. (B) is the SOC threshold value that was positively determined in S14 and changed in S18, and the hatched range is the decrease range. Here, an example in which the normal range is reduced by 5% is shown as the reduction range. That is, the charging start threshold is 35% and the charging end threshold is 45%.

  Of course, the lowering range may be determined by other settings. For example, the charging start threshold value may be lowered by 10% from the normal case, and the charging end threshold value may be the same as in the normal case. Preferably, the value between the charge start threshold value and the charge end threshold value is the same as that in the normal range, and the whole may be appropriately reduced. As a result, when the vehicle is going backward on the slope, the reduction in the driving force on the axle 32 caused by the start of the engine 28 can be delayed to achieve the target travel distance, and the additional charge of the same percentage as usual even when the forced charge starts. The charging can be terminated when the operation is performed, which can contribute to an improvement in fuel consumption.

  Returning to FIG. 5 again, when the SOC threshold value is set in one of the ranges in S16 and S18, the current SOC value is compared with the set SOC threshold value. First, it is determined whether or not the current SOC value is less than the SOC threshold value for starting charging (S20). If the determination is affirmative, forced charging is started (S22). Specifically, the engine 28 starts and the first rotating electrical machine 24 starts generating power.

  If the determination is negative in S20, it is next determined whether or not the current SOC value exceeds the SOC threshold value for termination of charging (S24). If the determination is affirmative, forced charging is terminated (S26). Specifically, the engine 28 is stopped and the power generation of the first rotating electrical machine 24 is finished. When the determination is negative, the first rotating electrical machine 24 is driven by the engine 28 to generate electric power, and the power storage device 12 is just being charged.

  In this way, the set SOC threshold value is compared with the current SOC value, and charging / discharging regarding power storage device 12 is controlled. These steps are executed by the function of the charge / discharge control processing unit 48 of the vehicle control device 40 based on the current SOC value calculated by the SOC calculation unit 38.

  Therefore, with the above-described configuration, when the vehicle 6 is in a reverse slope state and the slope is equal to or greater than a predetermined gradient slope, the SOC threshold is set lower than the normal one, so that the axle by starting the engine 28 is set. By delaying the decrease in the driving force at 32, the target traveling distance can be achieved in the backward traveling on the slope.

  The vehicle control device according to the present invention can be used for drive control of a vehicle equipped with an engine and a rotating electrical machine.

  4 road surface, 6 vehicle, 8 vehicle control system, 10 drive block, 12 power storage device, 14, 18 smoothing capacitor, 16 voltage converter, 20, 22 inverter, 24, 26 rotating electrical machine, 28 engine, 30 power distribution mechanism, 32 Axle, 34 Inclination sensor, 36 Shift position detection unit, 38 SOC calculation unit, 40 Vehicle control device, 42 Inclination acquisition processing unit, 44 Shift position acquisition processing unit, 46 SOC acquisition processing unit, 48 Charge / discharge control processing unit, 50 threshold change processing unit, 60 driving force required for climbing when starting, 62 driving force required for climbing when driving.

Claims (2)

A vehicle control device for a vehicle that distributes power among an engine, a rotating electric machine for power generation, and a rotating electric machine for traveling,
Shift position acquisition means for acquiring a shift position;
SOC acquisition means for acquiring the SOC value, which is the state of charge of the rotating electrical storage device,
When the SOC value falls below a predetermined charge start SOC value, the engine is started and forced charging by the rotating electric machine for power generation is started. When the SOC value rises above a predetermined charge end SOC value, charging is controlled to end the forced charge. A discharge controller;
Inclination degree acquisition means for acquiring the inclination degree of the vehicle according to the gradient inclination of the road surface;
A changing means for setting and changing the charging start SOC value to a lower value than in a normal case when the shift position is in the reverse range and the inclination is equal to or greater than a predetermined inclination threshold;
A vehicle control device comprising: The vehicle control device according to claim 1,
The changing means further changes the setting of the charge termination SOC value to a value lower than that in a normal case.

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