JP2010241260A - Controller and control method for hybrid vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To ensure restart of an engine and secure long-time drive in EV mode, in a hybrid vehicle having EV mode where a vehicle travels by a motor instead of the engine, and HV mode where the vehicle travels by both the engine and the motor. <P>SOLUTION: When an SOC becomes smaller than a predetermined value during EV mode (S100: YES), an ECU starts temporary cranking by driving an MG(1), and estimates the maximum friction Tf_max based on the minimum value of the angular acceleration of an MG(1) during the cranking (S200), and calculates an engine start power Pcrank based on the maximum friction Tf_max (S300), and until an allowable battery discharge power Wout becomes smaller than an engine start power Pcrank+threshold value α (S500: NO), continues traveling in EV mode (S700). <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to control of a hybrid vehicle.

  In recent years, a hybrid vehicle that travels by driving force from at least one of an engine and a traveling motor has been put into practical use as part of measures against environmental problems. In such a hybrid vehicle, when the engine is started, the engine is cranked by driving the traveling motor with electric power supplied from a power storage device such as a battery.

  In Japanese Patent Application Laid-Open No. 2008-25375 (Patent Document 1) and Japanese Patent Application Laid-Open No. 2008-25375 (Patent Document 2), in such a hybrid vehicle, the current value of the driving motor and the engine coolant temperature during cranking are described. Based on this, a technique for estimating the friction torque generated by the frictional resistance of the engine or the transaxle is disclosed.

JP 2005-155357 A JP 2008-25375 A JP 2007-261442 A

  By the way, the magnitude of the friction torque described above also varies depending on the crank angle of the engine. However, Patent Documents 1 to 3 described above do not disclose any friction torque calculation method considering fluctuations based on the crank angle of the engine.

  The present invention has been made in order to solve the above-described problems, and an object of the present invention is to use electric traveling in which a vehicle is driven by the power of a rotating electrical machine without using an internal combustion engine, and power of the internal combustion engine and the rotating electrical machine. To provide a control device and a control method capable of ensuring a long electric traveling time while guaranteeing restart of an internal combustion engine in a hybrid vehicle capable of switching to hybrid traveling for traveling the vehicle.

  A control device according to a first aspect of the invention controls a hybrid vehicle including a rotating electrical machine driven by electric power supplied from a power storage device and an internal combustion engine started by the rotating electrical machine. The control device includes an input unit to which information indicating a rotation angle of the rotating electrical machine and information indicating a state of the power storage device are input, and the internal combustion engine is temporarily rotated by the rotating electrical machine when a predetermined condition is satisfied, and the internal combustion engine is rotating. A torque calculation unit that calculates a resistance torque when starting the internal combustion engine based on a change in the rotation angle of the rotating electrical machine, a storage unit that stores the resistance torque calculated by the torque calculation unit, and a state of the power storage device A first power calculation unit that calculates a power value that can be output by the power storage device, and an internal combustion engine until the power value that can be output by the power storage device decreases to a power threshold value corresponding to the resistance torque stored in the storage unit. The hybrid vehicle is driven using the rotating electrical machine without using the engine, and the hybrid vehicle is driven using the internal combustion engine and the rotating electrical machine when the power value that can be output by the power storage device falls to the power threshold value. And a line control unit.

  In the control device according to the second invention, the torque calculation unit detects the minimum value of the rotational angular acceleration of the rotating electrical machine based on the change of the rotational angle, and the maximum value of the resistance torque based on the minimum value of the rotational angular acceleration. Is calculated.

  In the control device according to the third invention, the storage unit stores the minimum value of the rotational angular acceleration detected by the torque calculation unit. The torque calculation unit stops the temporary rotation of the internal combustion engine by the rotating electric machine after the minimum value of the rotation angular acceleration is stored in the storage unit, and the resistance torque is based on the minimum value of the rotation angular acceleration stored in the storage unit. The maximum value of is calculated.

  The control device according to a fourth aspect of the present invention further includes a second power calculation unit that calculates the maximum value of the power value required by the rotating electrical machine when starting the internal combustion engine by the rotating electrical machine based on the maximum value of the resistance torque. . The power threshold value is a value corresponding to the maximum power value required for the rotating electrical machine.

  In the control device according to the fifth aspect of the invention, the control device further includes a second power calculation unit that calculates a power value required by the rotating electrical machine when starting the internal combustion engine by the rotating electrical machine based on the resistance torque. The power threshold value is a value corresponding to the power value required for the rotating electrical machine.

  In the control device according to the sixth aspect of the invention, information related to the travel history of the hybrid vehicle is input to the input unit. The second power calculator reduces the power value required for the rotating electrical machine or the maximum value of the power value required for the rotating electrical machine according to the travel history.

  In the control device according to the seventh aspect of the invention, the rotating electrical machine functions as an electric motor when the internal combustion engine starts to rotate the internal combustion engine, and functions as an electric motor when the hybrid vehicle travels to drive the hybrid vehicle. And a second rotating electrical machine that generates torque for generating the torque.

  A control method according to an eighth aspect of the invention is a control method performed by a hybrid vehicle control device including a rotating electric machine driven by electric power supplied from a power storage device and an internal combustion engine started by the rotating electric machine. Information indicating the rotation angle of the rotating electrical machine and information indicating the state of the power storage device are input to the control device. The control method includes a step of temporarily rotating the internal combustion engine by the rotating electrical machine when a predetermined condition is satisfied, and calculating a resistance torque when starting the internal combustion engine based on a change in the rotation angle of the rotating electrical machine during rotation of the internal combustion engine; Storing the resistance torque calculated in the step of calculating the resistance torque, calculating the power value that can be output by the power storage device based on the state of the power storage device, and storing the power value that can be output by the power storage device The hybrid vehicle is driven using the rotating electrical machine without using the internal combustion engine until the power threshold value corresponding to the resistance torque stored in the step is reduced, and the power value that the power storage device can output is the power threshold. A hybrid vehicle using an internal combustion engine and a rotating electrical machine when the value is reduced to a value.

  According to the present invention, in a hybrid vehicle capable of switching between electric travel for traveling a vehicle using a rotating electrical machine without using an internal combustion engine and hybrid traveling for traveling the vehicle using an internal combustion engine and a rotating electrical machine, The electric travel time can be ensured for a long time while the restart of the engine is guaranteed.

It is a figure which shows the structure of the vehicle by which ECU which is a control apparatus which concerns on the 1st Embodiment of this invention is mounted. It is an alignment chart of a power split mechanism. It is a figure showing the relationship between a crank angle and an engine friction torque. It is a figure which shows the engine friction torque in the piston top dead center vicinity of an engine. It is a functional block diagram of ECU which concerns on the 1st Embodiment of this invention. It is a processing flow figure (the 1) of ECU concerning a 1st embodiment of the present invention. It is a processing flow figure (the 2) of ECU which concerns on a 1st embodiment of the present invention. It is a functional block diagram of ECU which concerns on the 2nd Embodiment of this invention. It is a processing flowchart of ECU which concerns on the 2nd Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same parts are denoted by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

<First Embodiment>
FIG. 1 is a diagram illustrating a structure of a vehicle 10 on which a control device according to the present embodiment is mounted. Vehicle 10 travels with a hybrid vehicle (HV) travel mode that travels with the power of both engine 100 and second motor generator (MG (2)) 300B, and travels with the power of MG (2) 300B while engine 100 is stopped. It is a hybrid vehicle capable of traveling in any one of the electric vehicle (EV) traveling modes. The vehicle 10 is a plug-in vehicle capable of traveling with electric power supplied from an AC power supply 19 provided outside the vehicle.

  The vehicle to which the control device according to the present invention can be applied is not limited to the hybrid vehicle shown in FIG. 1 as long as the vehicle can travel in one of the EV travel mode and the HV travel mode. The hybrid vehicle which has an aspect may be sufficient. Moreover, it is not necessarily a plug-in vehicle.

  Vehicle 10 includes, in addition to engine 100 and MG (2) 300B described above, first motor generator (MG (1)) 300A, power split mechanism 200, speed reducer 14, travel battery 310, inverter 330, boost converter. 320, engine ECU 406, MG_ECU 402, HV_ECU 404, and the like.

  Power split device 200 is constituted by a planetary gear mechanism (planetary gear). Power split device 200 distributes the power generated by engine 100 to MG (1) 300A and output shaft 212 (drive wheel 12 side). The output shaft 212 is connected to the rotation shaft of the MG (2) 300B. In this way, engine 100, MG (1) 300A, MG (2) 300B are connected via power split mechanism 200 including a planetary gear mechanism, so that engine 100, MG (1) 300A, MG ( 2) For example, as shown in FIG. 2, the rotational speed of 300 </ b> B has a relationship of being connected by a straight line in the alignment chart. By using this relationship to control the rotational speed of MG (1) 300A, power split device 200 also functions as a continuously variable transmission.

  The reducer 14 transmits power generated by the power split mechanism 200 and the engine 100, MG (1) 300A, MG (2) 300B to the drive wheels 12, and drives the drive wheels 12 to the engine 100 and MG (1 ) 300A and MG (2) 300B.

  Traveling battery 310 stores electric power for driving MG (1) 300A and MG (2) 300B.

  Inverter 330 performs current control while converting the DC power of traveling battery 310 and the AC power of MG (1) 300A and MG (2) 300B.

  Boost converter 320 performs voltage conversion between battery for traveling 310 and inverter 330.

  Engine ECU 406 controls the operating state of engine 100. MG_ECU 402 controls the charge / discharge states of MG (1) 300A, MG (2) 300B, inverter 330, and traveling battery 310 according to the state of vehicle 10. The HV_ECU 404 controls and controls the engine ECU 406, the MG_ECU 402, and the like so that the vehicle 10 can operate most efficiently.

  Further, the vehicle 10 converts the AC power from the connector 13 for connecting the paddle 15 connected to the AC power source 19 outside the vehicle and the AC power source 19 supplied via the connector 13 into DC power. And the charging device 11 that outputs to the traveling battery 310. Charging device 11 controls the amount of electric power output to traveling battery 310 in accordance with a control signal from HV_ECU 404.

  In FIG. 1, each ECU is configured separately, but may be configured as an ECU in which two or more ECUs are integrated. For example, as shown by a dotted line in FIG. 1, an example is an ECU 400 in which MG_ECU 402, HV_ECU 404, and engine ECU 406 are integrated. In the following description, MG_ECU 402, HV_ECU 404, and engine ECU 406 are described as ECU 400 without being distinguished from each other.

  ECU 400 includes a vehicle speed sensor, an accelerator opening sensor, a throttle opening sensor, an engine rotation speed sensor (all not shown), and the state of battery for traveling 310 (battery voltage value Vb, battery current value Ib, battery temperature THb). Etc.) is input from the monitoring unit 340.

  Further, the ECU 400 is connected to a rotation angle sensor (resolver) 360 that detects the displacement angle θ of the MG (1) 300A and a rotation angle sensor (not shown) that detects the displacement angle of the MG (2) 300B. .

  As described above, ECU 400 causes vehicle 10 to travel in one of the EV travel mode and the HV travel mode. When switching from the EV traveling mode to the HV traveling mode, it is necessary to crank and start engine 100 that has been stopped.

  At the time of cranking, as shown in FIG. 2, ECU 400 drives MG (1) 300A as a motor to generate torque in the forward direction (the direction in which the rotation of engine 100 is increased). Torque in the positive direction of MG (1) 300A is transmitted to the crankshaft of engine 100 through power split mechanism 200. Thereby, engine 100 is cranked. At the time of cranking, the friction torque acts in the negative direction (the direction in which the rotation of the engine 100 is suppressed) due to the frictional resistance of the transaxle including the engine 100 and the power split mechanism 200. Therefore, at the time of cranking, it is necessary to drive MG (1) 300A so that a positive torque larger than the friction torque acts on engine 100.

  However, the friction torque varies according to the crank angle (the rotation angle of the crankshaft of the engine 100). The fluctuation of the friction torque is greatest when the piston of the cylinder of the engine 100 passes through the top dead center, that is, where the piston changes from compression to expansion. As shown in FIG. 3 and FIG. 4, the friction torque has a minimum value (a value on the minimum point that changes from decrease to increase) immediately before the top dead center, and a maximum point (change from increase to decrease) immediately after top dead center. Value on the maximum point). This is because the vector F shown in FIG. 4A is in the direction opposite to the rotation direction of the crankshaft immediately before the top dead center, and the vector F ′ shown in FIG. It can be seen from the same direction as the rotation direction.

  Therefore, at the time of cranking, it is necessary to drive MG (1) 300A so that a positive torque larger than the minimum value of the friction torque acts on engine 100.

  A technical feature of the present embodiment is that ECU 400 takes into account the above-described variation in friction torque, and based on the minimum value of angular acceleration of MG (1) 300A during cranking, the minimum value of friction torque (friction). The maximum absolute value of torque (hereinafter also referred to as “maximum friction”) is accurately estimated, and by switching between EV traveling and HV traveling in consideration of the maximum friction, EV traveling to HV traveling is performed. The EV travel time is as long as possible while guaranteeing restart of the engine 100 at the time of transition.

  FIG. 5 shows a functional block diagram of ECU 400 according to the present embodiment. The ECU 400 includes an input interface 410 to which information indicating detection results of sensors such as a displacement angle θ, a battery voltage value Vb, a battery current value Ib, and a battery temperature THb is input, and various information, programs, threshold values, and maps. , Etc. are stored, and the arithmetic processing unit 420 that performs arithmetic processing based on information from the input interface 410 and the storage unit 430, and the arithmetic processing unit 420 that reads and stores data from the arithmetic processing unit 420 as necessary. And an output interface 440 that outputs the processing result of the arithmetic processing unit 420 to each device.

  The arithmetic processing unit 420 includes a maximum friction calculating unit 421, a starting power calculating unit 422, an SOC calculating unit 423, a Wout calculating unit 424, and a traveling control unit 425.

  Maximum friction calculation unit 421 calculates maximum friction Tf_max based on the minimum value of angular acceleration of MG (1) 300A during cranking.

  Specifically, maximum friction calculation unit 421 first drives MG (1) 300A as a motor when a predetermined condition is satisfied (for example, when a condition that the SOC described later is smaller than a predetermined value is satisfied). The engine 100 is temporarily cranked, the angular acceleration A of the MG (1) 300A is monitored based on the displacement angle θ at the time of cranking, and the friction torque Tf when the angular acceleration A becomes a minimum value is Calculated as the maximum friction Tf_max.

  For calculating the maximum friction Tf_max, an equation of motion of the vehicle when the vehicle is stopped can be used.

That is, the equation of motion of the vehicle at the time of cranking is expressed by the following equation (1).
I ′ × (dω1 / dt) = − Tf × {ρ / (1−ρ)} + T1 (1)
Here, I ′ = I1 + {ρ / (1 + ρ)} ² × Ie. However,
ρ: Planetary gear ratio of power split mechanism 200 I1: MG (1) 300A inertia moment Ie: Engine 100 inertia moment dω1 / dt: MG (1) 300A angular acceleration Tf: Engine 100 or transaxle friction torque T1: Therefore, the output torque of MG (1) 300A when the angular acceleration A is the minimum value and the angular acceleration A when the crank acceleration is the minimum value is the angular acceleration C and the output torque of the MG1 torque Tg, respectively. The friction torque Tf obtained by storing and substituting T1 = Tg and dω1 / dt = C into the above equation (1) may be set as the maximum friction Tf_max. Note that the method of calculating the maximum friction Tf_max is not limited to this.

  The starting power calculation unit 422 calculates a maximum value (hereinafter also referred to as “engine starting power”) Prank of power (electric power) necessary for cranking the engine 100 based on the maximum friction Tf_max. For example, the start power calculation unit 422 calculates a product of a predetermined target cranking rotation speed and the maximum friction Tf_max as the engine start power Pcrank.

  The SOC calculation unit 423 calculates a battery charge state value (a value indicating the charge state of the traveling battery 310) SOC (State Of Charge) based on the integrated value of the battery voltage value Vb and the battery current value Ib.

  Wout calculation unit 424 calculates battery allowable discharge power (upper limit value of power that can be discharged from traveling battery 310) Wout based on battery charge state value SOC, battery temperature THb, and the like.

  The traveling control unit 425 sets a value obtained by subtracting the engine start power Pcrank from the battery allowable discharge power Wout to the EV traveling maximum power Pev_max, and the EV traveling maximum power Pev_max becomes lower than a predetermined threshold value α. Until EVout mode is continued (that is, until Wout <Pcrank + α), EV driving maximum power Pev_max is lower than a predetermined threshold value α (that is, Wout <Pcrank + α). Then, the EV travel mode is switched to the HV travel mode.

  The threshold value α can be set by adaptation or the like. For example, when the threshold value α is set to 0 kw, the traveling control unit 425 continues the EV traveling until Wout <Prank, and switches from EV traveling to HV traveling when Wout <Pcrank. become.

  The functions described above may be realized by software or hardware.

  6 and 7 are flowcharts of the ECU 400 when the above-described functions are realized by software. These processes are repeated at a predetermined cycle time.

  FIG. 6 shows a processing flow performed by ECU 400 during traveling in the EV traveling mode. As shown in FIG. 6, at step (hereinafter, step is abbreviated as S) 100, ECU 400 determines whether or not the SOC is smaller than a predetermined value. This determination is to determine whether or not sufficient electric power for EV traveling is stored in the traveling battery 310. If a positive determination is made in this process (YES in S100), the process proceeds to S200, assuming that the maximum friction Tf_max needs to be calculated. If not (NO in S100), the process proceeds to S800.

  In S200, ECU 400 performs processing for estimating maximum friction Tf_max. Details of this processing are shown in FIG.

  In S300, ECU 400 calculates engine start power Prank based on maximum friction Tf_max. For example, as described above, ECU 400 calculates a product of a predetermined target cranking rotation speed and maximum friction Tf_max as engine starting power Pcrank.

  In S400, ECU 400 calculates a value obtained by subtracting engine start power Pcrank from battery allowable discharge power Wout as maximum EV travelable power Pev_max.

  In S500, ECU 400 determines whether EV travelable maximum power Pev_max is lower than threshold value α (that is, whether Wout <Pcrank + α). If a positive determination is made in this process (YES in S500), the process proceeds to S600. If not (NO in S500), the process proceeds to S700.

  In S600, ECU 400 causes vehicle 10 to travel in the HV travel mode. That is, switching from EV traveling to HV traveling is performed.

  In S700, ECU 400 continues traveling in the EV traveling mode. After the process of S700, the process is returned to S500, and the determination as to whether or not the EV traveling maximum power Pev_max is lower than the threshold value α is repeated.

In S800, ECU 400 continues traveling in the EV traveling mode.
The details of the maximum friction Tf_max estimation process (the process of S200 of FIG. 6) will be described with reference to FIG.

  In S202, ECU 400 determines whether or not maximum friction Tf_max needs to be calculated. This determination may be made based on whether or not the SOC is smaller than a predetermined value, for example, as in S100 of FIG. If a positive determination is made in this process (YES in S202), the process proceeds to S204. Otherwise (NO in S202), this process ends.

  In S204, ECU 400 drives MG (1) 300A as a motor and starts temporary cranking of engine 100.

  In S206, ECU 400 detects displacement angle θ of MG (1) 300A based on the signal from resolver 360.

  In S208, ECU 400 calculates angular velocity ω of MG (1) 300A based on displacement angle θ. For example, the ECU 400 calculates the angular velocity ω by subtracting the displacement angle θ of the previous cycle from the displacement angle θ of the current cycle detected in S206 and dividing the subtracted value by the cycle time.

  In S210, ECU 400 calculates angular acceleration A based on angular velocity ω. For example, ECU 400 calculates angular acceleration A by subtracting angular velocity ω of the previous cycle from angular velocity ω of the previous cycle calculated in S208 and dividing the subtracted value by the cycle time.

  In S212, ECU 400 determines whether angular acceleration A of the current cycle is smaller than angular acceleration B of the previous cycle, and whether the absolute value of the difference between angular acceleration A and angular acceleration B is smaller than a predetermined value. . This determination is to determine whether or not the angular acceleration A of the current cycle is a minimum value. If a positive determination is made in this process (YES in S212), the process proceeds to S214. If not (NO in S212), the process proceeds to S222.

  In S214, ECU 400 calculates the output torque of MG (1) 300A in the current cycle (that is, when angular acceleration A becomes the minimum value) based on the control signal to MG (1) 300A, etc. The torque Tg is stored in the storage unit 430.

  In S216, ECU 400 stores angular acceleration A (that is, the minimum value of angular acceleration A) of the current cycle in storage unit 430 as angular acceleration C.

  In S218, ECU 400 stops MG (1) 300A and ends temporary cranking of engine 100.

  In S220, ECU 400 calculates maximum friction Tf_max from angular acceleration C and MG1 torque TgC stored in storage unit 430. Note that, as described above, the equation of motion of the vehicle may be used to calculate the maximum friction Tf_max. Further, the calculated maximum friction Tf_max is stored in the storage unit 430 in the present process.

  In S222, ECU 400 stores angular acceleration A of the current cycle as angular acceleration B of the previous cycle. The angular acceleration B stored in this process is used for the process of S212 in the next cycle.

  An operation of ECU 400 that is the control device according to the present embodiment based on the above-described structure and flowchart will be described.

  ECU 400 predicts that switching to HV travel mode will be performed in the near future if the SOC decreases below a predetermined value while traveling in EV travel mode of vehicle 10 (YES in S100, YES in S202). The maximum friction Tf_max is estimated (S200).

  That is, ECU 400 starts temporary cranking by MG (1) 300A (204), and from the detected value of displacement angle θ of MG (1) 300A during this cranking, angular acceleration A of MG (1) 300A is detected. Is determined to be a minimum value (S206, S208, S210, S212).

  ECU 400 stores the output torque of MG (1) 300A and the minimum value of angular acceleration A when angular acceleration A reaches the minimum value (YES in S212) as MG1 torque Tg and angular acceleration C, respectively. (S214, S216) After finishing the temporary cranking (S218), the maximum friction Tf_max is calculated from the angular acceleration C and the MG1 torque TgC.

  In this way, when it is predicted that switching to the HV travel mode will be performed in the near future, ECU 400 drives MG (1) 300A as a motor to perform cranking temporarily, and during this cranking. The friction torque when the angular acceleration A of MG (1) 300A becomes a minimum value is calculated as the maximum friction Tf_max. For this reason, the maximum friction Tf_max is a highly accurate value in consideration of actual friction torque fluctuations.

  Then, ECU 400 calculates engine start power Pcrank based on maximum friction Tf_max calculated accurately as described above (S300), and until battery allowable discharge power Wout is lower than engine start power Pcrank + threshold value α. (NO in S500), the travel in the EV travel mode is continued (S700), and when the battery allowable discharge power Wout is lower than the engine start power Prank + threshold α (YES in S500), the EV travel mode Is switched to the HV running mode (S700). Therefore, the engine starting power Prank is set to a value higher than the actual maximum friction in advance in order to guarantee the restart of the engine 100, for example, while ensuring the restart of the engine 100 at the time of switching from the EV running mode to the HV running mode. Compared with the set case, the EV traveling time can be secured longer, so that the fuel consumption can be improved.

<Second Embodiment>
Hereinafter, a control device according to a second embodiment of the present invention will be described. The control device according to the present embodiment is obtained by adding a function of correcting (decreasing) the engine start power Pcrank according to the travel history of the vehicle to the control device according to the first embodiment. . Other functions are the same as those in the first embodiment. Therefore, detailed description here will not be repeated for the same functional block diagram and flowchart as those of the control device of the first embodiment.

  FIG. 8 shows a functional block diagram of ECU 400 according to the present embodiment. In the functional blocks shown in FIG. 8, the same functions as those shown in FIG. 5 are given the same numbers. Therefore, detailed description thereof will not be repeated here.

  The friction reduction amount prediction unit 426 calculates a friction torque reduction amount (friction reduction amount) ΔTf caused by a temperature increase (decrease in the viscosity of the lubricating oil) of the engine 100, the power split mechanism 200, and the like due to traveling. Calculation based on time, vehicle speed, output torque, engine coolant temperature, and history of lubricating oil temperature of engine 100 and power split mechanism 200).

  Then, the starting power calculation unit 428 calculates the engine starting power Prank based on a value obtained by subtracting the friction reduction amount ΔTf from the maximum friction Tf_max. Therefore, the engine start power Prank is reduced by a value corresponding to the friction reduction amount ΔTf.

  FIG. 9 is a flowchart of ECU 400 when the above-described functions are realized by software. In the flowchart shown in FIG. 9, the same steps as those in the flowchart shown in FIG. 6 are given the same step numbers. The processing is the same for them. Therefore, detailed description thereof will not be repeated here.

  In S1210, ECU 400 calculates a friction reduction amount ΔTf based on the travel history of the vehicle. ECU 400 calculates friction reduction amount ΔTf based on the history of travel time, vehicle speed, output torque, engine cooling water temperature, lubricating oil temperature of engine 100 and power split mechanism 200, etc. after calculation of maximum friction Tf_max, for example. To do.

  In S1220, ECU 400 calculates a correction value obtained by subtracting friction reduction amount ΔTf from maximum friction Tf_max.

  In S1300, ECU 400 calculates engine start power Prank based on a correction value obtained by subtracting friction reduction amount ΔTf from maximum friction Tf_max.

  In S1700, ECU 400 continues traveling in the EV traveling mode. After the process of S1700, the process returns to S1210.

  As described above, the ECU 400 according to the present embodiment increases the temperature (lubrication) of the engine 100, the power split mechanism 200, and the like due to traveling even after the maximum friction Tf_max is calculated in the maximum friction Tf_max estimation process (the process of S200). A reduction amount ΔTf of the friction torque caused by the oil viscosity reduction) is calculated based on the travel history of the vehicle (S1210), and the engine starting power Pcrank is reduced by a value corresponding to the friction reduction amount ΔTf (S1220, S1300). Therefore, it is possible to ensure a longer EV traveling time while guaranteeing restart of engine 100 when switching from the EV traveling mode to the HV traveling mode.

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

  DESCRIPTION OF SYMBOLS 10 Vehicle, 11 Charging device, 12 Drive wheel, 13 Connector, 14 Reducer, 15 Paddle, 19 AC power supply, 100 Engine, 200 Power split mechanism, 212 Output shaft, 310 Driving battery, 320 Boost converter, 330 Inverter, 340 Monitoring unit, 360 resolver, 400 ECU, 402 MG_ECU, 404 HV_ECU, 406 engine ECU, 410 input interface, 420 arithmetic processing unit, 421 maximum friction calculation unit, 422, 428 starting power calculation unit, 423 SOC calculation unit, 424 Wout calculation , 425 travel control unit, 426 friction reduction amount prediction unit, 430 storage unit, 440 output interface.

Claims (8)

A control device for a hybrid vehicle, comprising: a rotating electrical machine driven by electric power supplied from a power storage device; and an internal combustion engine started by the rotating electrical machine,
An input unit for inputting information indicating a rotation angle of the rotating electrical machine and information indicating a state of the power storage device;
Torque for calculating a resistance torque when the internal combustion engine is temporarily rotated by the rotating electrical machine when a predetermined condition is satisfied, and the internal combustion engine is started based on a change in the rotational angle of the rotating electrical machine during rotation of the internal combustion engine A calculation unit;
A storage unit for storing the resistance torque calculated by the torque calculation unit;
A first power calculation unit that calculates a power value that can be output by the power storage device based on a state of the power storage device;
Until the electric power value that can be output by the power storage device falls to the electric power threshold value corresponding to the resistance torque stored in the storage unit, the hybrid electric vehicle is used without using the internal combustion engine. And a travel control unit that causes the hybrid vehicle to travel using the internal combustion engine and the rotating electrical machine when a power value that can be output from the power storage device decreases to the power threshold value. Control device.   The torque calculation unit detects a minimum value of rotation angular acceleration of the rotating electrical machine based on the change in the rotation angle, and calculates a maximum value of the resistance torque based on the minimum value of the rotation angular acceleration. The hybrid vehicle control device according to claim 1. The storage unit stores a minimum value of the rotational angular acceleration detected by the torque calculation unit,
The torque calculation unit stops temporary rotation of the internal combustion engine by the rotating electrical machine after the minimum value of the rotation angular acceleration is stored in the storage unit, and the torque calculation unit stores the rotation angular acceleration stored in the storage unit. The hybrid vehicle control device according to claim 2, wherein the maximum value of the resistance torque is calculated based on a local minimum value. The control device further includes a second power calculation unit that calculates a maximum value of a power value required by the rotating electrical machine when starting the internal combustion engine by the rotating electrical machine based on the maximum value of the resistance torque,
The hybrid vehicle control device according to claim 2, wherein the power threshold is a value corresponding to a maximum value of a power value required for the rotating electrical machine. The control device further includes a second power calculation unit that calculates a power value required for the rotating electrical machine when starting the internal combustion engine by the rotating electrical machine based on the resistance torque,
The control apparatus for a hybrid vehicle according to claim 1, wherein the power threshold value is a value corresponding to a power value required for the rotating electrical machine. Information related to the travel history of the hybrid vehicle is input to the input unit,
6. The hybrid according to claim 4, wherein the second power calculation unit reduces a power value required for the rotating electrical machine or a maximum value of the power value required for the rotating electrical machine according to the traveling history. Vehicle control device.   The rotating electrical machine functions as an electric motor when the internal combustion engine is started to rotate the internal combustion engine, and generates torque for driving the hybrid vehicle by functioning as an electric motor when the hybrid vehicle is running. The control device for a hybrid vehicle according to claim 1, further comprising: A control method performed by a control device for a hybrid vehicle including a rotating electrical machine driven by electric power supplied from a power storage device and an internal combustion engine started by the rotating electrical machine, the control device including the rotating electrical machine Information indicating the rotation angle of the battery and information indicating the state of the power storage device are input,
The control method is:
A step of temporarily rotating the internal combustion engine by the rotating electrical machine when a predetermined condition is satisfied, and calculating a resistance torque when starting the internal combustion engine based on a change in a rotational angle of the rotating electrical machine during rotation of the internal combustion engine; When,
Storing the resistance torque calculated in the step of calculating the resistance torque;
Calculating a power value that the power storage device can output based on the state of the power storage device;
Until the electric power value that can be output by the power storage device falls to the electric power threshold value corresponding to the resistance torque stored in the storing step, the hybrid vehicle is used by using the rotating electrical machine without using the internal combustion engine. And driving the hybrid vehicle using the internal combustion engine and the rotating electrical machine when the power value that can be output from the power storage device drops to the power threshold value. Method.

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