JP2012224220A - Drive control device of hybrid vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve fuel consumption performance especially when cold.SOLUTION: A drive control device 30 mounted on an HV vehicle 10 includes: an operation control means 31 which drives an engine 11 at a target operating point Pe* that is the prescribed engine output target and assumes a difference between a requested power Pr* and the target operating point Pe* as an electrical charge and discharge amount of a battery 12 by MG1 and MG2; and an operating point change means 32 that changes the target operating point Pe* of the engine 11 before complete warming-up based on the prescribed change condition.

Description

  The present invention relates to a drive control device for a hybrid vehicle.

  In a hybrid vehicle, intermittent operation in which engine stop and restart are repeated is frequently performed. For this reason, in light urban driving, it takes a long time until the engine is completely warmed up. Generally, an engine is unstable in combustion at a low temperature and has a large amount of friction. Therefore, engine operation control in the cold state is important from the viewpoint of fuel efficiency.

  In view of such a situation, for example, Patent Document 1 discloses that a torque fluctuation of an internal combustion engine is detected by a rotating electric machine when a complete start-up explosion is detected under a low temperature condition. Has disclosed a start control device for a power unit that reduces the amount of power generation during fast idle operation.

  Further, in Patent Document 2, the engine load at the time of low temperature start is reduced to improve the startability, the engine is warmed up, and after the generated torque is increased, the limit of the output current of the generator is released and the battery is released. An output current control device for charging the battery is disclosed. Further, Patent Document 3 discloses a means for calculating a limit time until the actual output of the electric motor reaches the lower limit, and a start time calculation for calculating a time until the prime mover device including the catalyst device can drive the generator. There is disclosed a vehicle comprising means and means for operating a prime mover device when a limit time is less than or equal to a start time.

JP 2000-145497 A JP-A-7-170672 JP-A-9-154204

  By the way, the engine has an output with optimum thermal efficiency. However, the above-mentioned patent document does not disclose operation control in consideration of the thermal efficiency of the engine when cold. The conventional technology, for example, controls the operation of the engine based on the thermal efficiency in a completely warmed-up state, so there is still room for improvement from the viewpoint of improving fuel efficiency during cold weather.

  In addition, in a situation where the engine stop frequency is low, such as when there is a heater request, if the battery is charged a lot during cold and the battery charge rate (SOC: State Of Charge) becomes high, for example, the engine is operated after complete warm-up. It becomes difficult to optimally control the points. That is, it is important from the viewpoint of fuel efficiency improvement to perform engine operation control in cold conditions assuming the engine operating condition.

A drive control apparatus for a hybrid vehicle according to the present invention operates an engine at a target operating point that is a predetermined engine output, and uses the difference between the required power and the target operating point of the engine as a charge / discharge amount of the battery by the rotating electrical machine It has a control means and an operating point changing means for changing a target operating point of the engine before complete warm-up based on a predetermined changing condition.
According to this configuration, it is possible to set an appropriate target operating point from the viewpoint of improving fuel efficiency in consideration of the warm-up state of the engine and the operating state of the engine.

  Further, the operating point changing means preferably changes the target operating point based on the engine temperature so that the lower the temperature, the lower the output side.

The operating point changing means preferably changes the target operating point based on the temperature of the engine so that the thermal efficiency of the engine is maximized at each temperature.
According to this configuration, it is possible to set an appropriate target operating point in consideration of the thermal efficiency of each warm-up state according to the warm-up state of the engine, and the fuel efficiency performance particularly during cold weather is improved. This is based on the fact that the engine output at which the thermal efficiency is optimal differs depending on the warm-up state of the engine.

Further, the operating point changing means can shift the target operating point to the low output side in a predetermined operating state where the engine stop frequency is low.
In the operating state where the engine stop frequency is low, there are usually more charging opportunities and fewer discharging opportunities, but according to the configuration, the charging opportunity is reduced by shifting the target operating point to the low output side, or The amount of charge can be reduced. On the other hand, the discharge opportunity can be increased or the discharge amount can be increased. For this reason, for example, charging more than necessary during the warm-up operation of the engine can be suppressed, and the high charge rate can be suppressed.

The operating point changing means shifts the target operating point to the low output side according to the charging rate when the engine is in a predetermined operating state with a low stop frequency and the battery charging rate exceeds the first threshold. Can do.
According to this configuration, in an operating state where the engine stop frequency is low, by considering the charging rate of the battery, for example, when the charging rate is low, the engine is operated at a target operating point where the thermal efficiency of the engine is maximum. You can drive. On the other hand, when the charging rate is high, the target operating point can be shifted to the low output side according to the charging rate, and for example, the charging amount can be reduced or the discharging amount can be increased.

The operating point changing means shifts the target operating point to the high output side according to the charging rate when the engine is in a predetermined operating state with a low stop frequency and the charging rate of the battery is less than the second threshold value. be able to.
According to this configuration, when the charging rate is less than the second threshold value in an operating state where the engine stop frequency is low, the engine can be operated at a higher output to promote charging. For example, the second threshold value is preferably set to a charging rate equal to or lower than the first threshold value, and is set to a range between a lower limit value of the charging rate and a target charging rate.

  In addition, as an operation state in which the engine stop frequency is low, when there is a heater request, when the outside air temperature is a low temperature below a predetermined temperature, when the planned travel route registered in the navigation device is a high load travel route, And the state etc. which combined these can be illustrated.

  According to the hybrid vehicle drive control apparatus of the present invention, the fuel consumption performance is improved particularly in the cold state by controlling the engine operation in consideration of the thermal efficiency according to the warm-up state of the engine.

  Further, according to the drive control device for a hybrid vehicle according to the present invention, by performing engine operation control in the cold state assuming the operation state of the engine, for example, charging is performed more than necessary during the cold state. It can suppress that a rate stops high. For this reason, it becomes easy to optimally control the operating point of the engine after complete warm-up, and the fuel efficiency performance after complete warm-up is improved.

1 is a block diagram illustrating a schematic configuration of a drive control device and a hybrid vehicle according to an embodiment of the present invention. In the drive control apparatus which is embodiment of this invention, it is a figure which shows the relationship between engine thermal efficiency, an engine output, and a target operating point. In the drive control apparatus which is embodiment of this invention, it is a figure which shows the relationship between engine thermal efficiency, an engine output, and a target operating point. In the drive control apparatus which is embodiment of this invention, it is a figure which shows the relationship between engine thermal efficiency, an engine output, and a target operating point. It is a figure which shows a mode that the cooling water temperature of an engine changes according to the driving | running | working state of a hybrid vehicle. It is a map which prescribes | regulates the relationship between SOC and basic charge / discharge amount. It is a flowchart which shows an example of the control by the drive control apparatus which is embodiment of this invention.

Hereinafter, an example of an embodiment of the present invention will be described in detail with reference to the drawings.
First, with reference to FIG. 1, the structure of the drive control apparatus 30 and the hybrid vehicle 10 (henceforth HV vehicle 10) which are embodiment of this invention is demonstrated in detail. In addition to FIG. 1, FIGS. 2 to 6 will be referred to as appropriate.

FIG. 1 is a diagram showing a schematic configuration of an HV vehicle 10 on which a drive control device 30 is mounted.
As shown in FIG. 1, the HV vehicle 10 includes an engine 11 that is a driving power source, a first motor generator (hereinafter referred to as MG1) that mainly functions as a generator, and a first motor that mainly functions as a driving motor. Two motor generators (hereinafter referred to as MG2), a battery 12 capable of supplying power to MG1 and MG2, and the operation of the engine 11, MG1, and MG2 based on the accelerator opening, the vehicle speed, the SOC of the battery 12, etc. And a drive control device 30 to be controlled.

  Further, the HV vehicle 10 includes an engine 11, an MG 1, an MG 2, a power distribution mechanism 13 that distributes power to the engine 11, inverters 14 and 15 that are AC / DC converters, and a drive control device 30. 11, an engine electronic control unit 16 (hereinafter referred to as an engine ECU 16) that controls the operation of the battery, a battery monitoring device 17 that monitors the SOC of the battery 12, and various sensors (not shown) that detect information necessary for vehicle drive control (for example, , An accelerator position sensor and a vehicle speed sensor) are mounted.

  The HV vehicle 10 includes a heater core 18 that uses the cooling water of the engine 11 as a heat medium, a blower motor and switching doors (not shown), a water temperature sensor 19 that detects the cooling water temperature, An outside air temperature sensor 20 for detecting the outside air temperature, a heater switch 21 for turning on / off the heater, and the like are provided.

  The engine 11 is an internal combustion engine that uses gasoline or the like as a fuel. As shown in FIGS. 2 to 4 (a diagram showing the relationship between the thermal efficiency of the engine, the engine output, and the target operating point), the engine having the optimum thermal efficiency. Output exists. In a general engine 11, combustion becomes unstable and friction increases at low temperatures. The engine output at which the thermal efficiency is optimal shifts to a lower output side, that is, a lower load side as the temperature of the engine 11 is lower. The engine 11 is provided with a cooling facility for circulating cooling water. As described above, this cooling water is also used as a heat medium for the interior heating equipment.

  The engine 11 is controlled in operating state including warm-up operation via the engine ECU 16 based on a control command from the drive control device 30. The engine ECU 16 is connected to various sensors (for example, an air flow meter, a crank angle sensor, a throttle position sensor, and an air-fuel ratio sensor) that detect the operating state of the fuel injection valve and the engine 11. The output shaft 22 extending from the engine 11 to the power distribution mechanism 13 is provided with a rotation sensor for detecting the rotation speed of the engine 11, and the detection information is also input to the engine ECU 16. Information detected by the water temperature sensor 19 is also input to the engine ECU 16.

  The engine 11 is provided with a catalytic converter disposed upstream of the exhaust pipe, a sub-muffler disposed downstream of the catalytic converter, a main muffler disposed downstream of the sub-muffler, and the like as exhaust equipment. The catalytic converter is a device that purifies by oxidizing and reducing harmful substances in the exhaust gas, and preferably includes a so-called three-way catalyst that can simultaneously purify HC, CO, and NOx. For example, the sub-muffler is provided with an exhaust heat recovery mechanism that circulates the cooling water of the engine 11 and promotes the rise of the cooling water temperature. Further, the exhaust equipment is provided with, for example, an exhaust gas recirculation (EGR) device that reintroduces a part of the exhaust gas to the intake side.

  In the HV vehicle 10, the interior of the vehicle is heated using the heater core 18 that uses the coolant of the engine 11 as a heat medium. For example, when the heater is requested, the engine 11 is warmed up in order to quickly increase the coolant temperature. Driving is performed. The warm-up operation is also performed when the power of the engine 11 is not required for vehicle travel, such as during low-load travel. For this reason, when there is a heater request, the stop frequency of the engine 11 is reduced. For example, the power of the engine 11 due to the warm-up operation during low-load traveling is exclusively used for power generation by the MG1. Examples of the situation in which the engine 11 is warmed up include cases where the temperature of the catalyst is low, the temperature of the battery 12 is low, or the outside air temperature is low, in addition to the heater request.

  The power distribution mechanism 13 is preferably configured by, for example, a planetary gear mechanism. The power input from the engine 11 to the power distribution mechanism 13 via the output shaft 22 is transmitted to the drive wheels 27 via the speed reducer 25 and the axle 26. Further, part or all of the power of the engine 11 can be transmitted to the MG 1.

  The rotation shaft 23 of the MG 1 is connected to the output shaft 22 of the engine 11 via the power distribution mechanism 13. Alternatively, the output shaft 22 of the engine 11 and the rotation shaft 23 of the MG 1 are configured as a common shaft. The MG 1 functions as a generator driven mainly by the engine 11. MG1 is, for example, a three-phase synchronous rotating electric machine including a rotor made of permanent magnets and a stator including U-phase, V-phase, and W-phase stator coils. The three-phase alternating current generated by the MG 1 is converted into a direct current by the inverter 14 and then charged to the battery 12. Moreover, MG1 functions as a cell motor that starts the engine 11, for example.

  MG2 mainly functions as a traveling motor. As with MG1, MG2 is preferably a three-phase synchronous rotating electrical machine. MG2 is rotationally driven by electric power supplied from battery 12. Specifically, the direct current of the battery 12 is converted into a three-phase alternating current by the inverter 15 and supplied to the MG2. The output of MG2 is transmitted to the drive wheels 27 via the power distribution mechanism 13, the speed reducer 25, and the axle 26 to which the rotary shaft 24 is connected. As a result, the HV vehicle 10 can travel by assisting the engine 11 with MG2 or EV traveling using only MG2 as a power source. MG2 functions as a generator during regenerative braking.

  Battery 12 is a power storage device that mainly supplies power to MG2. A secondary battery such as a nickel cadmium battery, a nickel metal hydride battery, or a lithium ion battery is applied to the battery 12. From the viewpoint of efficient use, prevention of deterioration, and the like, the battery 12 has a management range (for example, 20% to 80%) with a predetermined SOC as an upper and lower limit value, and a target SOC (for example, a charge / discharge standard) 60%) is set.

  The SOC control of the battery 12 is executed by the drive control device 30. For example, the drive control device 30 acquires the SOC information from the battery monitoring device 17 and controls the operations of the MG1, MG2, and the engine 11 so that the battery 12 is not overcharged or overdischarged. The battery monitoring device 17 monitors the state of the battery 12 including the SOC using, for example, a voltmeter, an ammeter, a thermometer, or the like. The SOC can be calculated based on the integrated value of the charge / discharge current.

  The inverters 14 and 15 are AC / DC converters as described above. For example, the inverter 14 has a function of charging the battery 12 by converting an alternating current generated by the MG 1 into a direct current by ON / OFF operation of the semiconductor switching element under the control of the drive control device 30. Further, the inverter 14 has a function of converting the direct current of the battery 12 into an alternating current and supplying the alternating current to the MG 1 in order to generate a generator torque corresponding to the required power generation amount. For example, the inverter 15 has a function of converting a direct current of the battery 12 into an alternating current and supplying the alternating current to the MG 2 under the control of the drive control device 30.

  The drive control device 30 is a device that controls the driving force of the HV vehicle 10, and can be configured as a so-called hybrid ECU or a part thereof. The drive control device 30 integrally controls the operations of the MG1, MG2, and the engine 11 based on information and signals from each sensor and each ECU. The drive control device 30 and each ECU are configured by a microcomputer including a CPU, an input / output port, a memory, and the like, and each function of the drive control device 30 can be realized by executing software.

The drive control device 30 operates the engine 11 at a target operating point Pe ^*, which is a predetermined engine output, and sets the difference between the required power Pr ^* and the target operating point Pe ^* as the charge / discharge amount of the battery 12 by MG1 and MG2. Operation control means 31 is provided. It is preferable that the operation control means 31 operates the engine 11 at the target operating point Pe ^* in a range where the SOC of the battery 12 does not exceed the upper and lower limit values.

As will be described in detail later, when the target operating point Pe ^* is changed by the operating point changing unit 32 before the engine is completely warmed up, that is, when it is cold, the operation control unit 31 uses the engine at the changed target operating point Pe ^* . 11 is driven. Hereinafter, required by, called modified target operating point Pe ^* and the corrected target operating point Pe ^*, referred to as a further change corrected target operating point Pe ^* with additional correction target operating point Pe ^*.

For example, the target operating point Pe ^* is set to an engine output at which the thermal efficiency of the engine 11 is maximized when the engine 11 is completely warmed up. The required power Pr ^* is, for example, power (vehicle required power) obtained by adding the basic charge / discharge amount derived from the SOC to the travel required power derived from the accelerator opening and the vehicle speed.

The operation control means 31 acquires data necessary for vehicle drive control such as accelerator opening, vehicle speed, battery 12 SOC, battery 12 temperature and input / output restrictions set from the SOC, and sets the operation mode. While setting, it controls the operating state of the engine 11 and MG1 and MG2. The operation modes, for example, in a range where the SOC of the battery 12 does not exceed the upper limit value, and operating the engine 11 at the target operating point Pe ^*, the difference between the target operating point Pe ^* and the power demand of the vehicle Pr ^* MG1 , Normal operation mode for charging / discharging the battery 12 by MG2, forced charge mode selected when SOC falls below the lower limit, forced discharge mode selected when SOC exceeds the upper limit, engine 11 is stopped There is an EV traveling mode in which power is supplied only from MG2.

  The operation control means 31 can set the basic charge / discharge amount based on the SOC. The basic charge / discharge amount is set such that the SOC acquired from the battery monitoring device 17 approaches a predetermined target SOC (for example, 60%). It is preferable that the operation control unit 31 sets the basic charge / discharge amount from the SOC using a map that defines the relationship between the SOC and the basic charge / discharge amount illustrated in FIG. 6. In this map, for example, the basic charge / discharge amount at the target SOC is set to 0, and the basic charge / discharge amount increases as the distance from the target SOC increases. In a region exceeding the upper and lower limit values of the SOC, a certain basic charge / discharge amount is defined.

  Further, the operation control means 31 can set the charge / discharge upper and lower limit amounts based on the SOC and the vehicle speed. The charge / discharge upper / lower limit amount is set, for example, so as to suppress the charge amount in the high vehicle speed region more than the low vehicle speed region and suppress the discharge amount in the low vehicle speed region more than in the high vehicle speed region. For example, the charge / discharge upper / lower limit amount can be set from the SOC and the vehicle speed using a map that defines the relationship among the SOC, the vehicle speed, and the charge / discharge upper / lower limit amount.

Further, the operation control means 31 can set the required power Pr ^* based on the accelerator opening and the vehicle speed. For example, using the required torque setting map, the required travel torque is derived from the accelerator opening and the vehicle speed, and the required travel power is derived by multiplying the rotational speed of the output shaft connected from the power distribution mechanism 13 to the axle 26. Then, the required power Pr ^* is calculated by adding the basic charge / discharge amount to the required travel power.

As described above, the operation control unit 31 operates the engine 11 at the target operating point Pe ^* in a range where the SOC of the battery 12 does not exceed the upper and lower limit values. For example, as shown in FIGS. 2 and 3, when the required power Pr ^* is smaller than the target operating point Pe ^* of the engine 11, the battery 12 is charged by converting the excess output by MG 1. On the other hand, as shown in FIG. 4, when the vehicle required power Pr ^* is larger than the target operating point Pe ^* of the engine 11, the insufficient output is assisted by MG2. That is, the battery 12 is discharged. That is, since the difference between the required power Pr ^* and the target operating point Pe ^* is the charge / discharge amount, the operation control means 31 can calculate the charge / discharge amount based on the required power Pr ^* . It is preferable that the operation control means 31 performs an upper / lower limit guard process so that the calculated value of the charge / discharge amount does not exceed the charge / discharge upper / lower limit amount.

The drive control device 30 includes operating point changing means 32 that changes the target operating point Pe ^* of the engine 11 before complete warm-up based on a predetermined changing condition.

As shown in FIG. 2, the operating point changing unit 32 preferably changes the target operating point Pe ^* of the engine 11 before complete warm-up based on the temperature of the engine 11. Note that T1, T2, and T3 in FIG. 2 are the temperatures of the engine 11, and T1 <T2 <T3. That is, in the present embodiment, it is preferable that the target operating point Pe ^* is not a constant value before and after the complete warm-up, but is a variable value that changes according to the warm-up state of the engine 11. . As a result, even if the required power Pr ^* is the same, the charge / discharge amount varies depending on the warm-up level.

  The temperature of the engine 11 may be determined based on, for example, the temperature of exhaust gas or the temperature of engine oil, but is preferably determined based on the coolant temperature of the engine 11. The operating point changing means 32 can acquire detection information of the water temperature sensor 19 via the engine ECU 16, for example. Below, it demonstrates as what determines the temperature of the engine 11 based on a cooling water temperature.

The operating point changing unit 32 preferably changes the target operating point Pe ^* based on the cooling water temperature so that the lower the cooling water temperature is, the lower the output side is. In other words, full Danki sets the corrected target operating point Pe ^* before the low-load side than the target operating point Pe ^* in a fully warmed-up state ^{(e.g., Pe * (T2) <Pe} * (T3)), the cooling water It is preferable to shift the corrected target operating point Pe ^* to the low load side as the temperature decreases (for example, Pe ^* (T1) <Pe ^* (T2)). As a result, the lower the cooling water temperature, the smaller the charge amount or the greater the discharge amount.

The operating point changing means 32 preferably changes the target operating point Pe ^* so that the thermal efficiency of the engine 11 is maximized in each warm-up state. As described above, since the engine output at which the thermal efficiency is maximized differs depending on the warm-up state of the engine 11, the operating point changing unit 32 sets the corrected target operating point Pe ^* to the engine output at which the thermal efficiency is maximized at each warm-up state. The target operating point Pe ^* is changed so as to be set. Thereby, even when the warm-up state of the engine 11 is different, the engine 11 can be operated under a condition with high thermal efficiency, and the fuel efficiency performance is improved particularly during cold weather.

In the example shown in FIG. 2, the engine output at which the thermal efficiency becomes maximum shifts to the low load side as the temperature of the engine 11 is lower. Therefore, when the target operating point Pe ^* is changed so that the thermal efficiency of the engine 11 is maximized in each warm-up state, the corrected target operating point Pe ^* is shifted to the low load side as the cooling water temperature is lower. On the other hand, when the engine output at which the thermal efficiency is maximized is shifted to the high load side as the cooling water temperature is lower, the target operating point is set so that the corrected target operating point Pe ^* is shifted to the higher output side as the cooling water temperature is lower. Pe ^* may be changed. As such an engine 11, for example, an engine using engine oil whose friction is low on the low temperature side can be exemplified.

Furthermore, it is preferable that the operating point changing means 32 shifts the target operating point Pe ^* to the low output side in a predetermined operating state where the stop frequency of the engine 11 is low.

As shown in FIGS. 3 and 4, the operating point changing means 32, the corrected target operating point Pe ^* at each cooling water temperature, after changing the target operating point Pe ^* as thermal efficiency of the engine 11 becomes the maximum Furthermore, it is more preferable to change the corrected target operating point Pe ^* assuming the operating condition of the engine 11. On the other hand, the operating point changing means 32 does not change the target operating point Pe ^* based on, for example, the coolant temperature of the engine 11 and the operating state of the HV vehicle 10 is an operating state in which the stop frequency of the engine 11 is low. As a condition, the target operating point Pe ^* may be changed.

The predetermined operation state in which the stop frequency of the engine 11 is low includes a state in which the stop frequency of the engine 11 is likely to be low. As the predetermined operation state, for example, when there is a heater request, when the outside air temperature is a low temperature below a predetermined temperature, when the planned travel route registered in the navigation device 28 is a preset high load travel route, A case where a plurality of these conditions are combined can be exemplified. For example, the operating point changing unit 32 stores these states as a predetermined operating state in which the stop frequency of the engine 11 is low, and determines that the operating state of the HV vehicle 10 is a pre-stored operating state. The target operating point Pe ^* can be changed.

For example, when there is a heater request, the operating point changing unit 32 further shifts the corrected target operating point Pe ^* to the low output side. The operating point changing means 32 can acquire the ON operation signal of the heater switch 21 and change the corrected target operating point Pe ^* when the signal is acquired. Alternatively, the operating point changing means 32 outputs the corrected target operating point Pe ^* at a lower output when the outside air temperature is a low temperature below the predetermined temperature, or when there is a heater request and the outside air temperature is below the predetermined temperature. Shift to the side. The operating point changing means 32 can acquire the outside air temperature from the outside air temperature sensor 20, compare the outside air temperature with a predetermined temperature, and change the corrected target operating point Pe ^* when the outside air temperature <the predetermined temperature. .

  The predetermined temperature can be set, for example, to a temperature (for example, 10 ° C.) determined in advance as a temperature at which a heater request is assumed. Alternatively, it is also possible to store the outside air temperature at which the frequency with which the user makes a heater request is stored, and set the temperature to a predetermined temperature. When the outside air temperature is low, the engine 11 is not easily warmed up, and the engine 11 is likely to be cooled again even once it is completely warmed up. For this reason, the frequency of warm-up operation is increased, and in particular, the frequency of stopping the engine 11 is likely to be decreased.

Further, the operating point changing means 32 outputs the corrected target operating point Pe ^* even lower when, for example, there is a heater request and the scheduled traveling route registered in the navigation device 28 is a preset high-load traveling route. Shift to the side. The operating point changing means 32 can acquire the operation signal of the heater switch 21 and the registration information of the planned travel route of the navigation device 28 and determine whether or not to change the corrected target operating point Pe ^* . Examples of the high-load traveling route include an expressway that is supposed to travel at a high speed and an uphill road with a large gradient.

For example, when there is a heater request, the operating point changing unit 32 is configured to set the target operating point Pe ^* to a low output side by a predetermined amount corresponding to the operating state, for example, in an operating state where the stop frequency of the engine 11 is low. Can be shifted. More preferably, in the operating state where the stop frequency of the engine 11 is low, the shift amount of the target operating point Pe ^* is changed in consideration of the SOC of the battery 12.

For example, when there is a heater request, the operating point changing unit 32 is in a predetermined operating state where the stop frequency of the engine 11 is low, and when the SOC of the battery 12 exceeds the first threshold, the target operating point is set according to the SOC. Shift Pe ^* to the low output side. The first threshold value is preferably set between the target SOC and the lower limit value (for example, 20% to 60%), and can be the same value (for example, 60%) as the target SOC. The operating point changing means 32 can increase the shift amount of the target operating point Pe ^* as the SOC increases when the SOC exceeds the first threshold. For example, the target operating point Pe ^* can be changed using a map that defines the SOC and the shift amount.

On the other hand, the operating point changing means 32 is in a predetermined operating state where the stop frequency of the engine 11 is low, for example, when there is a heater request, and when the SOC of the battery 12 is less than the second threshold value, according to the SOC. The target operating point Pe ^* can be shifted to the high output side. The second threshold value is preferably set between the target SOC and the lower limit value (for example, 20% to 60%), similarly to the first threshold value. The second threshold value can be set in the vicinity of the lower limit value from the viewpoint of suppressing the charging opportunity before complete warm-up. Alternatively, the first threshold value and the second threshold value may be set to the same value.

For example, when there is a heater request, the operating point changing unit 32 changes the target operating point Pe ^* with the target SOC as a boundary. Specifically, when there is a heater request, when the SOC exceeds the target SOC, the target operating point Pe ^* is shifted to the low output side based on the SOC, and there is a heater request, and the SOC is less than the target SOC Next, the target operating point Pe ^* is shifted to the high output side based on the SOC.

In the example shown in FIGS. 3 and 4 (the case where the cooling water temperature is T2 is illustrated), the first threshold value is set to a value larger than the second threshold value. For example, when there is a heater request and the SOC is a high SOC exceeding the first threshold value, the corrected target operating point Pe ^* is further shifted to the low load side, and the corrected target operating point Pe ^* > the additional corrected target operating point Pe ^*. It becomes. On the other hand, when the SOC is a low SOC lower than the second threshold value, the corrected target operating point Pe ^* is shifted to the high load side, and the corrected target operating point Pe ^* <the additional corrected target operating point Pe ^* . When the SOC is not less than the second threshold and not more than the first threshold, the corrected target operating point Pe ^* is not changed. As a result, compared with the case where the SOC is equal to or higher than the second threshold value and equal to or lower than the first threshold value, the charge amount at the high SOC decreases, and the charge amount at the low SOC increases. On the other hand, compared with the case where the SOC is not less than the second threshold value and not more than the first threshold value, the discharge amount at high SOC increases and the discharge amount at low SOC decreases.

Next, an example of control by the drive control device 30 will be described with reference to FIG.
FIG. 7 shows an operation state in which the SOC is in a range not exceeding the upper and lower limit values and the normal operation mode is selected. In other words, this is an operation state in which the power of the engine 11 is required for traveling of the HV vehicle 10, and the engine 11 is operated at the target operating point Pe ^* .

  First, the basic charge / discharge amount is set from the SOC (S10). The basic charge / discharge amount can be set using a map illustrated in FIG. 6 based on the SOC acquired from the battery monitoring device 17. This procedure is executed by the function of the operation control means 31.

  Subsequently, a charge / discharge upper and lower limit amount is set from the SOC and the vehicle speed (S11). The charge / discharge upper / lower limit amount can be set using a map that defines the relationship between the SOC, the vehicle speed, and the charge / discharge upper / lower limit amount based on the vehicle speed obtained from the SOC and the vehicle speed sensor, and is used for upper / lower limit guard processing. Is done. This procedure is executed by the function of the operation control means 31.

Subsequently, a target operating point Pe ^* is calculated based on the coolant temperature of the engine 11 (S12). That is, the target operating point Pe ^* is changed according to the coolant temperature of the engine 11. As described above, the target operating point Pe ^* is changed using the map that defines the relationship between the cooling water temperature and the target operating point Pe ^* so that the thermal efficiency of the engine 11 is maximized under each cooling water temperature condition. The This procedure is executed by the function of the operating point changing means 32.

Subsequently, the charge / discharge amount is calculated based on the required power Pr ^* (S13). The required power Pr ^* is calculated by adding the basic charge / discharge amount to the travel required power derived based on the accelerator opening and the vehicle speed. The charge / discharge amount is obtained by subtracting the required power Pr ^* from the target operating point Pe ^*. Is calculated by This procedure is executed by the function of the operation control means 31.

  Subsequently, it is determined whether or not there is a heater request (S14). The presence or absence of a heater request can be determined by the presence or absence of an ON operation signal for the heater switch 21. This procedure is executed by the function of the operating point changing means 32. In addition to the heater request, the operating point changing unit 32 can determine whether or not the operating state of the HV vehicle 10 is an operating state in which the stop frequency of the engine 11 is low or likely to be low.

When it is determined in S14 that there is a heater request, it is determined whether or not the engine 11 is completely warmed up (S15). On the other hand, when it is determined in S14 that there is no heater request, the target operating point Pe ^* changed in S12 is maintained and the calculated value of the charge / discharge amount is not changed, so the process proceeds to the upper / lower limit guard process (S18). This procedure is executed by the function of the operating point changing means 32.

When it is determined in S15 that the engine is not completely warmed up, the SOC is determined (S16). On the other hand, when it is determined in S15 that the engine is completely warmed up, the changed target operating point Pe ^* is maintained and the calculated value of the charge / discharge amount is not changed, so the process proceeds to the upper / lower limit guard process (S18). In this procedure, the SOC acquired from the battery monitoring device 17 is compared with two threshold values to determine whether or not the SOC is greater than or equal to a second threshold value and less than or equal to a first threshold value. This procedure is executed by the function of the operating point changing means 32.

If it is determined in S16 that the SOC is not greater than or equal to the second threshold value and less than or equal to the first threshold value, that is, if the SOC exceeds the first threshold value or the SOC is less than the second threshold value, the target operating point Pe ^{* is set} to the SOC. The calculated value of the charge / discharge amount is corrected by changing it accordingly (S17). This procedure is executed by the function of the operating point changing means 32.

  Finally, an upper / lower limit guard process is performed so that the charge / discharge amount does not exceed the charge / discharge upper / lower limit amount set in S11 (S18).

As described above, the drive controller 30 operates the engine 11 at the target operating point Pe ^*, the required power Pr ^* and the charge-discharge amount of the battery 12 by the MG1, MG2 difference between the target operating point Pe ^* The operation control means 31 and the operating point changing means 32 for changing the target operating point Pe ^* of the engine 11 before complete warm-up based on a predetermined changing condition.

For example, the operating point changing unit 32 changes the target operating point Pe ^* based on the temperature of the engine 11 so that the thermal efficiency of the engine 11 is maximized at each temperature. Thereby, the target operating point Pe ^* in consideration of the thermal efficiency in each warm-up state can be set, and the engine 11 can be operated more efficiently. Therefore, the fuel consumption performance is improved particularly during cold weather.

The operating point changing unit 32 changes the target operating point Pe ^* according to the SOC in consideration of the SOC in an operating state where the stop frequency of the engine 11 is low, for example, when there is a heater request. Thereby, in the operating state where the stop frequency of the engine 11 is low, for example, the target operating point Pe ^* can be shifted to the low output side to reduce the charging opportunity or the charging amount. On the other hand, the discharge opportunity can be increased or the discharge amount can be increased. At this time, the engine 11 can be operated at the engine output at which the thermal efficiency is maximized in a state where there is a low possibility that the SOC will remain high, such as when the SOC is low.

  The design of the above embodiment can be changed within a range that does not impair the object of the present invention.

  DESCRIPTION OF SYMBOLS 10 Hybrid vehicle (HV vehicle), MG1 1st motor generator, MG2 2nd motor generator, 11 Engine, 12 Battery, 13 Power distribution mechanism, 14, 15 Inverter, 16 Engine electronic control unit (Engine ECU), 17 Battery monitoring device , 18 Heater core, 19 Water temperature sensor, 20 Outside air temperature sensor, 21 Heater switch, 22 Output shaft, 23, 24 Rotating shaft, 25 Reducer, 26 Axle, 27 Drive wheel, 28 Navigation device, 30 Drive control device, 31 Driving Control means, 32 operating point changing means.

Claims (8)

An operation control means for operating the engine at a target operating point which is a predetermined engine output, and setting a difference between the required power and the target operating point of the engine as a charge / discharge amount of the battery by the rotating electrical machine;
Operating point changing means for changing the target operating point of the engine before complete warm-up based on a predetermined change condition;
A drive control apparatus for a hybrid vehicle, comprising: In the hybrid vehicle drive control device according to claim 1,
The operating point changing means changes the target operating point based on the temperature of the engine so as to shift to a lower output side as the temperature is lower. In the hybrid vehicle drive control device according to claim 1 or 2,
The operating point changing means changes the target operating point based on the temperature of the engine so that the thermal efficiency of the engine is maximized at each temperature. In the hybrid vehicle drive control device according to any one of claims 1 to 3,
The operating point changing means shifts the target operating point to a low output side in a predetermined operating state where the engine stop frequency is low. In the hybrid vehicle drive control device according to any one of claims 1 to 3,
The operating point changing means shifts the target operating point to the low output side according to the charging rate when the engine is in a predetermined operating state with a low stop frequency and the charging rate of the battery exceeds the first threshold value. A drive control apparatus for a hybrid vehicle. In the hybrid vehicle drive control device according to claim 5,
The operating point changing means shifts the target operating point to the high output side according to the charging rate when the charging rate of the battery is less than the second threshold value. In the hybrid vehicle drive control device according to any one of claims 4 to 6,
The operating point changing means sets a predetermined operating state in which the engine stop frequency is low when at least one of the case where there is a heater request and the outside air temperature is equal to or lower than a predetermined temperature. apparatus. In the hybrid vehicle drive control device according to any one of claims 4 to 6,
The operating point changing means sets a predetermined driving state in which the engine stop frequency is low when the planned driving route registered in the navigation device is a preset high-load driving route. Control device.

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