JP6651930B2 - Hybrid car - Google Patents

Description

  The present invention relates to a hybrid vehicle, and more particularly, to a hybrid vehicle including an engine, two motors, a planetary gear, a transmission, and a battery.

  2. Description of the Related Art Conventionally, in a method of determining a degree of deterioration of a battery capacity (full charge capacity) of a secondary battery configured as a lithium ion battery, an internal state of the secondary battery is estimated according to a battery model formula, and a charging rate is determined based on the estimation result. And the battery current is estimated, and the degree of deterioration of the battery capacity is determined using an error between the integrated value of the battery current (actual current) measured by the current sensor and the estimated value of the battery current with respect to the estimated charging rate. (For example, see Patent Document 1).

JP 2010-60384 A

  Generally, it is preferable to estimate the degree of deterioration of the full charge capacity of the secondary battery when the absolute value of the battery current is small in order to ensure the accuracy. However, in a hybrid vehicle that runs with power from an engine or a motor while charging and discharging the battery as needed, when the vehicle continues to travel under a high load such as traveling on an uphill road, a state in which the absolute value of the battery current is large continues. In some cases, the opportunity for estimating the degree of deterioration of the full charge capacity of the secondary battery may decrease.

  A main object of the hybrid vehicle of the present invention is to secure an opportunity to estimate the degree of deterioration of the full charge capacity of the battery.

  The hybrid vehicle of the present invention employs the following means to achieve the above-described main object.

The hybrid vehicle of the present invention
The engine,
A first motor;
A transmission connected to a drive shaft connected to the axle;
A planetary gear in which three rotating elements are connected to three axes of an output shaft of the engine, a rotating shaft of the first motor, and an input shaft of the transmission;
A second motor connected to the input shaft;
A battery configured as a lithium ion secondary battery and exchanging power with the first motor and the second motor;
Control means for controlling the engine, the first motor, the second motor, and the transmission such that a required torque required for the drive shaft is output to the drive shaft;
A hybrid vehicle comprising:
When the absolute value of the current of the battery is equal to or less than a predetermined current, a deterioration degree estimating unit that estimates the degree of deterioration of the full charge capacity of the battery,
Prepare,
When the absolute value of the current of the battery is larger than the predetermined current for a predetermined time, the control means may control a required power required for an input shaft of the transmission according to a required torque required for the drive shaft. Is output from the engine and means for controlling the transmission to be downshifted.
That is the gist.

  In the hybrid vehicle of the present invention, when the absolute value of the battery current is equal to or smaller than the predetermined current, the degree of deterioration of the full charge capacity of the battery is estimated. When the absolute value of the battery current is greater than the predetermined current for a predetermined time, the required power required for the input shaft of the transmission according to the required torque required for the drive shaft is output from the engine and Control so that the transmission is downshifted. By outputting the required power required for the input shaft of the transmission from the engine, charging and discharging of the battery can be suppressed to some extent. However, since the response of the engine is generally lower than the response of the motor, it is considered that when the required torque of the drive shaft changes, the torque of the second motor changes and the battery is charged and discharged. By downshifting the transmission, the reduction ratio of the transmission (the number of rotations of the input shaft of the transmission / the number of rotations of the drive shaft) increases, so that the change in the required torque of the drive shaft requires the input shaft of the transmission. It is considered that the change in torque can be reduced, the change in torque (current) of the second motor can be reduced, and the current of the battery can be more reliably reduced to a predetermined current or less. As a result, it is possible to secure an opportunity to estimate the degree of deterioration of the full charge capacity of the battery.

  In the hybrid vehicle according to the present invention, the deterioration degree estimating means may be configured such that a concentration difference variation, which is a variation of the lithium ion concentration difference in the positive electrode active material in the battery, is equal to or less than a predetermined variation, and the absolute value of the battery current is the same. When the current is equal to or less than a predetermined current, the control unit is configured to estimate a degree of deterioration of a full charge capacity of the battery, and the control unit is configured to determine whether the concentration difference variation is larger than the predetermined variation over a second predetermined time, or When the absolute value of the battery current is greater than the predetermined current over the predetermined time, the required power required for the input shaft of the transmission according to the required torque required for the drive shaft is output from the engine. And the transmission may be controlled to be downshifted. Here, the “concentration difference variation” can be estimated based on the amount of change in the battery current per unit time. By performing such control, when the concentration difference variation is larger than a predetermined variation or when the absolute value of the battery current is larger than the predetermined current, the concentration difference variation can be more reliably reduced to a predetermined value or less, or the battery current can be reduced to a predetermined value. It is considered that the current can be more reliably maintained.

FIG. 1 is a configuration diagram illustrating an outline of a configuration of a hybrid vehicle 20 as one embodiment of the present invention. 5 is a flowchart illustrating an example of an estimation routine executed by a battery ECU 52 according to the embodiment.

  Next, an embodiment for carrying out the present invention will be described using an embodiment.

  FIG. 1 is a configuration diagram schematically showing a configuration of a hybrid vehicle 20 as one embodiment of the present invention. As shown, the hybrid vehicle 20 of the embodiment includes an engine 22, a planetary gear 30, motors MG1, MG2, inverters 41, 42, a transmission 60, a battery 50, and a hybrid electronic control unit (hereinafter, referred to as a hybrid electronic control unit). “HVECU”) 70.

  The engine 22 is configured as an internal combustion engine that outputs power using gasoline, light oil, or the like as fuel. The operation of the engine 22 is controlled by an engine electronic control unit (hereinafter, referred to as “engine ECU”) 24.

  Although not shown, the engine ECU 24 is configured as a microprocessor centered on a CPU, and includes, in addition to the CPU, a ROM for storing a processing program, a RAM for temporarily storing data, an input / output port, and a communication port. . Signals from various sensors necessary for controlling the operation of the engine 22, for example, a crank angle θcr from the crank position sensor 23 and the like are input to the engine ECU 24 from an input port. Various control signals for controlling the operation of the engine 22 are output from the engine ECU 24 via output ports. The engine ECU 24 is connected to the HVECU 70 via a communication port. The engine ECU 24 calculates the rotational speed Ne of the engine 22 based on the crank angle θcr from the crank position sensor 23.

  The planetary gear 30 is configured as a single pinion type planetary gear mechanism. The rotor of the motor MG1 is connected to the sun gear of the planetary gear 30. The input shaft 61 of the transmission 60 is connected to the ring gear of the planetary gear 30. The carrier of the planetary gear 30 is connected to the crankshaft 26 of the engine 22 via a damper 28.

  The motor MG1 is configured as, for example, a synchronous generator motor, and the rotor is connected to the sun gear of the planetary gear 30 as described above. The motor MG <b> 2 is configured as, for example, a synchronous generator motor, and the rotor is connected to the input shaft 61 of the transmission 60. Inverters 41 and 42 are used to drive motors MG1 and MG2, and are connected to battery 50 via power line 54. The motors MG1 and MG2 are rotationally driven by a motor electronic control unit (hereinafter, referred to as “motor ECU”) 40 that performs switching control on a plurality of switching elements (not shown) of the inverters 41 and 42.

  Although not shown, the motor ECU 40 is configured as a microprocessor centered on a CPU, and includes, in addition to the CPU, a ROM for storing a processing program, a RAM for temporarily storing data, an input / output port, and a communication port. . The motor ECU 40 receives signals from various sensors necessary to drive and control the motors MG1 and MG2, for example, rotational positions θm1 from rotational position detection sensors 43 and 44 for detecting the rotational positions of the rotors of the motors MG1 and MG2. , Θm2, etc. are input via the input port. From the motor ECU 40, a switching control signal or the like to a switching element (not shown) of the inverters 41 and 42 is output via an output port. The motor ECU 40 is connected to the HVECU 70 via a communication port. The motor ECU 40 calculates the rotational speeds Nm1 and Nm2 of the motors MG1 and MG2 based on the rotational positions θm1 and θm2 of the rotors of the motors MG1 and MG2 from the rotational position detection sensors.

  The transmission 60 is configured as a four-speed transmission, and has an input shaft 61 connected to a ring gear of the planetary gear 30 and a rotor (rotating shaft) of the motor MG2, and driving wheels 38a and 38b via a differential gear 37. An output shaft 62 connected to the connected drive shaft 36, a plurality of planetary gear mechanisms, and a plurality of hydraulically driven frictional engagement elements (clutch, brake) are provided. The transmission 60 transmits power in four stages between the input shaft 61 and the output shaft 62.

  Battery 50 is configured as a lithium ion secondary battery, and is connected to inverters 41 and 42 via power line 54. The battery 50 is managed by a battery electronic control unit (hereinafter, referred to as “battery ECU”) 52.

  Although not shown, the battery ECU 52 is configured as a microprocessor centered on a CPU, and includes, in addition to the CPU, a ROM for storing a processing program, a RAM for temporarily storing data, an input / output port, and a communication port. . The battery ECU 52 includes signals from various sensors necessary for managing the battery 50, for example, a voltage Vb from a voltage sensor 51a attached between terminals of the battery 50, and a current sensor attached to an output terminal of the battery 50. The current Ib from 51b is input via the input port. Battery ECU 52 is connected to HVECU 70 via a communication port. The battery ECU 52 calculates the power storage rate SOC based on the integrated value of the current Ib from the current sensor 51b and the voltage Vb.

  Although not shown, the HVECU 70 is configured as a microprocessor centering on a CPU, and includes, in addition to the CPU, a ROM for storing a processing program, a RAM for temporarily storing data, an input / output port, and a communication port. Signals from various sensors are input to the HVECU 70 via input ports. The signals input to the HVECU 70 include, for example, the rotation speed Np of the drive shaft 36 from a rotation speed sensor 69 attached to the drive shaft 36 (the output shaft 62 of the transmission 60), an ignition signal from an ignition switch 80, and a shift. The shift position SP from the position sensor 82 can be exemplified. Further, the accelerator opening Acc from the accelerator pedal position sensor 84, the brake pedal position BP from the brake pedal position sensor 86, the vehicle speed V from the vehicle speed sensor 88, and the like can also be mentioned. From the HVECU 70, a control signal and the like to the transmission 60 are output via an output port. As described above, the HVECU 70 is connected to the engine ECU 24, the motor ECU 40, and the battery ECU 52 via the communication port.

  In the hybrid vehicle 20 according to the embodiment configured as described above, the engine 22 and the motors MG1 and MG2 (hereinafter, referred to as a “hybrid unit”) are shifted so as to travel in a hybrid traveling (HV traveling) mode or an electric traveling (EV traveling) mode. Device 60 is controlled. Here, the HV traveling mode is a mode in which the vehicle travels with the operation of the engine 22, and the EV traveling mode is a mode in which the vehicle travels without the operation of the engine 22. Hereinafter, control of the hybrid unit in the EV running mode, control of the hybrid unit in the HV running mode, and control of the transmission 60 will be described.

  Control of the hybrid unit in the EV running mode will be described. The HVECU 70 first sets the required torque Tout * of the drive shaft 36 based on the accelerator opening Acc and the vehicle speed V. Subsequently, the rotational speed Nm2 of the motor MG2 (the rotational speed of the input shaft 61 of the transmission 60) is divided by the rotational speed Nout of the drive shaft 36 to calculate the reduction ratio Gr of the transmission 60, and the required torque of the drive shaft 36 is calculated. The required torque Tin * required for the input shaft 61 of the transmission 60 is calculated by dividing Tout * by the reduction ratio Gr of the transmission 60. Then, a value 0 is set to the torque command Tm1 * of the motor MG1, the required torque Tin * of the input shaft 61 of the transmission 60 is set to the torque command Tm2 * of the motor MG2, and the set torque command Tm1 of the motor MG1, MG2 is set. *, Tm2 * are transmitted to the motor ECU 40. Motor ECU 40 performs switching control of a plurality of switching elements of inverters 41 and 42 such that motors MG1 and MG2 are driven by torque commands Tm1 * and Tm2 *.

  Control of the hybrid unit in the HV running mode will be described. The HVECU 70 first determines the required torque Tout * of the drive shaft 36 (the output shaft 62 of the transmission 60), the reduction ratio Gr of the transmission 60, and the required torque Tin * of the input shaft 61 of the transmission 60, as described above. Set. Subsequently, the required power input to the input shaft 61 of the transmission 60 by multiplying the required torque Tin * of the input shaft 61 of the transmission 60 by the rotation speed Nm2 of the motor MG2 (the rotation speed of the input shaft 61 of the transmission 60). The required power required for the engine 22 is calculated by calculating Pin * and subtracting the required charge / discharge power Pb * (positive value when discharging from the battery 50) based on the storage rate SOC of the battery 50 from the calculated required power Pin *. Calculate Pe *. Then, the target rotation speed Ne * and the target torque Te * of the engine 22 are set using the required power Pe * and the operation line of the engine 22 (for example, the fuel consumption operation line). Subsequently, as shown in the following equation (1), the torque command Tm1 * of the motor MG1 is set by the rotation speed feedback control for setting the rotation speed Ne of the engine 22 to the target rotation speed Ne *. In the equation (1), “ρ” is a reduction ratio of the planetary gear 30 (the number of teeth of the sun gear / the number of teeth of the ring gear), “kp” is a gain of a proportional term, and “ki” is a gain of an integral term. . Then, as shown in Expression (2), when the motor MG1 is driven by the torque command Tm1 *, the torque (−Tm1 * / ρ) output from the motor MG1 and acting on the drive shaft 36 via the planetary gear 30 is represented by: The torque command Tm2 * of the motor MG2 is calculated by subtracting the required torque Tin * of the input shaft 61 of the transmission 60. Then, it transmits the target rotation speed Ne * and the target torque Te * of the engine 22 to the engine ECU 24 and transmits the torque commands Tm1 * and Tm2 * of the motors MG1 and MG2 to the motor ECU 40. The engine ECU 24 performs intake air amount control, fuel injection control, ignition control, and the like of the engine 22 so that the engine 22 is operated based on the target rotation speed Ne * and the target torque Te *. Motor ECU 40 performs switching control of a plurality of switching elements of inverters 41 and 42 such that motors MG1 and MG2 are driven by torque commands Tm1 * and Tm2 *.

Tm1 * =-ρ ・ Te * / (1 + ρ) + kp ・ (Ne * -Ne) + ki ・ ∫ (Ne * -Ne) dt (1)
Tm2 * = Tin * + Tm1 * / ρ (2)

  Control of the transmission 60 will be described. The HVECU 70 basically sets the normal speed Gsno based on the accelerator opening Acc and the vehicle speed V, sets the normal speed Gsno to the target speed Gs *, and sets the speed Gs of the transmission 60 to Gsno. The transmission 60 is controlled so as to reach the target shift speed Gs *.

  Next, an operation of the hybrid vehicle 20 according to the embodiment configured as described above, particularly, an operation when estimating the degree of deterioration Ds of the full charge capacity Sfull of the battery 50 will be described. FIG. 2 is a flowchart illustrating an example of an estimation routine executed by the battery ECU 52 according to the embodiment. This routine is repeatedly executed.

  When the estimation routine of FIG. 2 is executed, the battery ECU 52 first determines the current Ib of the battery 50, the charge rate SOC of the battery 50, and the concentration difference variation as the variation of the lithium ion concentration difference in the positive electrode active material in the battery 50. Data such as θ is input (step S100). Here, the value detected by the current sensor 51b is input as the current Ib of the battery 50. As the charge ratio SOC of the battery 50, a value calculated based on the integrated value of the current Ib and the voltage Vb is input. As the density difference variation θ, a value estimated based on the variation per unit time of the current Ib of the battery 50 in a predetermined time (for example, 500 msec, 800 msec, 1000 msec, etc.) is input. In the embodiment, when the current fluctuation rate Ri, which is the ratio of the fluctuation amount per unit time of the current Ib of the battery 50 to the current Ib, is small, the density difference variation θ is estimated to be smaller than when the current fluctuation rate Ri is large. .

  When the data is input in this way, it is determined whether the storage rate SOC of the battery 50 is within a predetermined high region or within a predetermined low region (step S105). Here, the predetermined high area may be, for example, an area of 70% to 80%. The predetermined low region can be, for example, a region of 30% to 40%. When the state of charge SOC of the battery 50 is neither within the predetermined high region nor within the predetermined high region, this routine is terminated as it is.

  When the storage rate SOC of the battery 50 is within the predetermined high range or the predetermined low range in step S105, the density difference variation θ is compared with the threshold value θref (step S110). Here, the threshold value θref is a threshold value used for determining whether or not the concentration difference variation θ is small enough to be suitable for estimating the degree of deterioration Ds of the full charge capacity Sfull of the battery 50. A value corresponding to the density difference variation θ when the rate Ri is a predetermined change rate (for example, 3%, 5%, 7%, etc.) can be used.

  If the concentration difference variation θ is equal to or smaller than the threshold value θref in step S110, it is determined that the concentration difference variation θ is small enough to be suitable for estimating the degree of deterioration Ds of the full charge capacity Sfull of the battery 50, and the absolute value of the current Ib of the battery 50 is determined. The value is compared with a threshold value Ibref (step S120). Here, the threshold value Ibref is a threshold value used to determine whether the absolute value of the current Ib of the battery 50 is small enough to be suitable for estimating the degree of deterioration Ds of the full charge capacity Sfull of the battery 50, For example, 9A, 10A, 11A and the like can be used.

  When the absolute value of the current Ib of the battery 50 is equal to or smaller than the threshold value Ibref in step S120, it is determined that the absolute value of the current Ib of the battery 50 is small enough to be suitable for estimating the degree of deterioration Ds of the full charge capacity Sfull of the battery 50. Then, the degree of deterioration Ds of the full charge capacity Sfull of the battery 50 is estimated (calculated) (step S130).

  As shown in the following equation (3), the process in step S130 includes an integrated current value Ibsum [Ah] which is an integrated value of the current Ib of the battery 50, a high power storage ratio SOCH [%], and a low power storage ratio SOCL [%]. Is used to calculate the full charge capacity Sfull [Ah] of the battery 50, and as shown in equation (4), divide this full charge capacity Sfull by the full charge capacity Sfullset in the initial state (at the time of factory shipment or replacement, etc.). Then, the degree of degradation Ds of the full charge capacity Sfull of the battery 50 is calculated to calculate the degree of deterioration. The smaller the value of the degree of deterioration Ds of the full charge capacity Sfull of the battery 50 thus estimated, the more the deterioration of the battery 50 is advanced.

Sfull = Ibsum ・ 100 / (SOCH-SOCL) (3)
Ds = Sfull / Sfullset (4)

  Here, the high power storage rate SOCH is the battery 50 when the power storage rate SOC of the battery 50 is within a predetermined high range, the concentration difference variation θ is equal to or less than the threshold value θref, and the absolute value of the current Ib of the battery 50 is equal to or less than the threshold value Ibref. Of the battery 50 estimated based on the voltage Vb of the battery 50. The low charge rate SOCL is the voltage Vb of the battery 50 when the charge rate SOC of the battery 50 is within a predetermined low range, the concentration difference variation θ is equal to or less than the threshold value θref, and the absolute value of the current Ib of the battery 50 is equal to or less than the threshold value Ibref. Is the power storage ratio SOC estimated based on

  When the power storage rate SOC of the battery 50 is within the predetermined high range in step S105 during the current execution of this routine, in the process of step S130, first, the high power storage rate SOCH is estimated based on the voltage Vb of the battery 50. Subsequently, the high power storage rate SOCH, the latest low power storage rate SOCL estimated up to that time, and the integrated value of the current Ib from the time when the latest low power storage rate SOCL is estimated to the time when this routine is executed this time. The deterioration degree Ds of the full charge capacity Sfull of the battery 50 is estimated using the integrated current value Ibsum. Then, the degree of deterioration Ds of the full charge capacity Sfull of the battery 50 is calculated by dividing the full charge capacity Sfull by the full charge capacity Sfullset in the initial state.

  Further, when the power storage ratio SOC of the battery 50 is within the predetermined low range in step S105 during the current execution of this routine, in the process of step S130, first, the low power storage ratio SOCL is estimated based on the voltage Vb of the battery 50. I do. Subsequently, the low power storage rate SOCL, the latest high power storage rate SOCH estimated up to that time, and the integrated value of the current Ib from the time when the latest high power storage rate SOCH is estimated to the time when this routine is executed this time are The deterioration degree Ds of the full charge capacity Sfull of the battery 50 is estimated using the integrated current value Ibsum. Then, the degree of deterioration Ds of the full charge capacity Sfull of the battery 50 is calculated by dividing the full charge capacity Sfull by the full charge capacity Sfullset in the initial state.

  After estimating the degree of deterioration Ds of the full charge capacity Sfull of the battery 50 in this way, a value 1 is set to the estimation completion flag F1 (step S140). On the other hand, when the absolute value of the current Ib of the battery 50 is larger than the threshold value Ibref in step S120, the absolute value of the current Ib of the battery 50 is not suitable for estimating the degree of deterioration Ds of the full charge capacity Sfull of the battery 50. It is determined that it is not small, and the degree of deterioration Ds of the full charge capacity Sfull of the battery 50 is not estimated, and the value 0 is set to the estimation completion flag F1 (step S150). Here, the estimation completion flag F1 is a flag indicating whether or not the degree of deterioration Ds of the full charge capacity Sfull of the battery 50 has been estimated at the time of this execution of this routine.

  Next, the value of the current adjustment flag F2 is checked (step S160). Here, the current adjustment flag F2 is a flag indicating whether or not the HVECU 70 has been instructed to execute a process of setting the absolute value of the current Ib of the battery 50 to be equal to or smaller than the threshold value Ibref (hereinafter, referred to as “current adjustment process”). It is.

  When the value of the current adjustment flag F2 is 0 in step S160, it is determined that the HVECU 70 has not been instructed to execute the current adjustment process, and the value of the estimation completion flag F1 is checked (step S170). When the estimation completion flag F1 has a value of 1, it is determined that the degree of deterioration Ds of the full charge capacity Sfull of the battery 50 has been estimated at the time of this execution of this routine, and the current adjustment process is not instructed to the HVECU 70. The value 0 is set to the adjustment flag F2 (step S180), and this routine ends.

  If the estimation completion flag F1 is 0 in step S170, it is determined that the deterioration degree Ds of the full charge capacity Sfull of the battery 50 has not been estimated at the time of this execution of this routine, and the estimation completion flag F1 is set to 0. The continuation time is compared with a predetermined time T1 (step S190). Here, the predetermined time T1 is an allowable range of time during which the degree of deterioration Ds of the full charge capacity Sfull of the battery 50 is not estimated, and for example, 400 seconds, 500 seconds, 600 seconds, or the like can be used.

  In step S190, when the continuation time when the estimation completion flag F1 is 0 is shorter than the predetermined time T1, the time during which the degree of deterioration Ds of the full charge capacity Sfull of the battery 50 is not estimated does not continue so long (allowable range). ), The current adjustment flag F2 is set to a value of 0 (step S180) without instructing the HVECU 70 to execute the current adjustment process, and the routine ends.

  In step S190, when the continuation time when the estimation completion flag F1 is 0 is equal to or longer than the predetermined time T1, the time during which the degree of deterioration Ds of the full charge capacity Sfull of the battery 50 is not estimated has continued to some extent (exceeding the allowable range) ), And instructs the HVECU 70 to execute the current adjustment process, specifically, the power adjustment process and the lowest speed process (step S200), and sets a value 1 to the current adjustment flag F2 (step S210). This routine ends. Here, the power adjustment process is a process of adjusting the required power Pe * of the engine 22, and the lowest speed process is a process of setting the speed Gs of the transmission 60 to the lowest speed.

  The HVECU 70 starts the execution of the power adjustment processing and the lowest speed processing when receiving the instructions. In the power adjustment process, instead of setting the required power Pe *, the target rotation speed Ne *, the target torque Te *, and the torque commands Tm1 * and Tm2 * of the motors MG1 and MG2 as described above, the battery 50 is used. Irrespective of the power storage ratio SOC, the required power Pe * is set by setting the required charge / discharge power Pb * to 0 (the required power Pin * is set to the required power Pe *), and the engine 22 is operated based on the required power Pe *. , A target rotation speed Ne *, a target torque Te *, and torque commands Tm1 *, Tm2 * of the motors MG1, MG2. In the lowest speed process, the lowest speed is set as the target speed Gs * instead of setting the normal speed Gsno as the target speed Gs *. That is, when the normal shift speed Gsno is not the lowest shift speed, the shift speed Gs of the transmission 60 is downshifted to the lowest shift speed when the lowest shift speed command is received from the battery ECU 52.

  By setting the required power Pin * of the input shaft 61 of the transmission 60 to the required power Pe *, the charging and discharging of the battery 50 can be suppressed to some extent. However, in general, the responsiveness of the engine 22 is lower than the responsiveness of the motors MG1 and MG2. Therefore, when the required torque Tout * of the drive shaft 36 changes, the torque command Tm2 * of the motor MG2 changes and the battery 50 Is considered to be performed. In consideration of this, by downshifting the transmission 60 to the lowest speed, the reduction ratio Gr (Nm2 / Nout) of the transmission 60 increases, so that the transmission with respect to the change in the required torque Tout * of the drive shaft 36 is changed. 60, the change in the required torque Tin * of the input shaft 61 of the motor 60 can be reduced, the change in the torque Tm2 (current) of the motor MG2 can be reduced, and the current Ib of the battery 50 can be more reliably kept below the threshold value Ibref. It is thought that it is possible.

  When this routine is executed next time, if the absolute value of the current Ib of the battery 50 is equal to or smaller than the threshold value Ibref in step S120, the degree of deterioration Ds of the full charge capacity Sfull of the battery 50 is estimated (step S130), and the estimation completion flag is set. A value is set to F1 (step S140). In this manner, an opportunity to estimate the degree of deterioration Ds of the full charge capacity Sfull of the battery 50 can be secured. When the absolute value of the current Ib of the battery 50 is larger than the threshold value Ibref in Step S120, the value 0 is set in the estimation completion flag F1 without estimating the degree of deterioration Ds of the full charge capacity Sfull of the battery 50 (Step S150). ).

  If the current adjustment flag F2 is equal to 1 in step S160, the value of the estimation completion flag F1 is checked (step S220). When the estimation completion flag F1 has a value of 0, it is determined that the deterioration degree Ds of the full charge capacity Sfull of the battery 50 has not been estimated at the time of this execution of this routine, and this routine ends.

  When the estimation completion flag F1 is equal to 1 in step S220, it is determined that the degree of deterioration Ds of the full charge capacity Sfull of the battery 50 has been estimated during the current execution of this routine, and the current adjustment processing, specifically, the power adjustment processing In addition, the HVECU 70 is instructed to terminate the execution of the lowest speed process (step S230), the value 0 is set to the current adjustment flag F2 (step S240), and the routine ends. HVECU 70 terminates the execution of the power adjustment process and the lowest speed process upon receiving an instruction to terminate the execution.

  When the concentration variation θ is larger than the threshold value θref in step S110, it is determined that the concentration difference variation θ is not small enough to be suitable for estimating the degree of deterioration Ds of the full charge capacity Sfull of the battery 50, and the concentration variation θ is set to the threshold value θref. The continuation time in the state larger than the predetermined time is compared with the predetermined time T2 (step S250). Here, the predetermined time T2 is an allowable range of the continuous time in a state where the density variation θ is larger than the threshold value θref, and for example, 400 sec, 500 sec, 600 sec can be used.

  In step S250, when the continuation time in the state where the density variation θ is larger than the threshold value θref is shorter than the predetermined time T2, it is determined that this state does not continue so long (within the allowable range), and the present routine ends. I do.

  In step S250, when the continuation time in the state where the density variation θ is larger than the threshold value θref is equal to or longer than the predetermined time T2, it is determined that this state has continued to some extent (exceeded the allowable range), and the above-described processing in step S200 is performed. Similarly, the HVECU 70 is instructed to execute the current adjustment process, specifically, the power adjustment process and the lowest speed process (step S260).

  Then, by performing the power adjustment process and the lowest speed process by the HVECU 70, the density difference variation θ can be more reliably set to the threshold value θref or less (and the current Ib of the battery 50 is set to the threshold value Ibref or less) for the same reason as described above. It is considered possible. In consideration of this, the density difference variation θ is input (step S270), and the process waits until the density difference variation θ becomes equal to or less than the threshold value θref (step S280). When the density difference variation θ becomes equal to or smaller than the threshold value θref, the HVECU 70 is instructed to terminate the execution of the current adjustment process, specifically, the power adjustment process and the lowest speed process, as in the process of step S230 (step S230). S290), this routine ends. In this manner, when the density difference variation θ is larger than the threshold value θref, the density difference variation θ can be set to the threshold value θref or less.

  In the hybrid vehicle 20 of the embodiment described above, when the absolute value of the current Ib of the battery 50 is equal to or smaller than the threshold value Ibref, the deterioration degree Ds of the full charge capacity Sfull of the battery 50 is estimated. When the absolute value of the current Ib of the battery 50 is larger than the threshold value Ibref for a predetermined time T1, the required power Pin * of the input shaft 61 of the transmission 60 is output from the engine 22 and the required torque Tin * is input. The engine 22 and the motors MG1 and MG2 are controlled so as to be output to the shaft 61, and the transmission 60 is controlled such that the transmission 60 is downshifted to the lowest speed. Thereby, it is considered that the current Ib of the battery 50 can be more reliably maintained at the predetermined current Ibref or less. As a result, it is possible to secure an opportunity to estimate the degree of deterioration Ds of the full charge capacity Sfull of the battery 50.

  In the hybrid vehicle 20 of the embodiment, when the concentration difference variation θ is equal to or less than the threshold value θref and the absolute value of the current Ib of the battery 50 is equal to or less than the threshold value Ibref (steps S110 and S120), the degree of deterioration of the full charge capacity Sfull of the battery 50 is reduced. Ds was estimated. However, when the absolute value of the current Ib of the battery 50 is equal to or smaller than the threshold value Ibref without considering the concentration difference variation θ (without performing the processing of step S110), the degree of deterioration Ds of the full charge capacity Sfull of the battery 50 is reduced. May be estimated.

  In the hybrid vehicle 20 of the embodiment, when the absolute value of the current Ib of the battery 50 is larger than the threshold value Ibref for a predetermined time T1, the transmission 60 is downshifted to the lowest speed. However, if the absolute value of the current Ib of the battery 50 is lower than the shift speed Gs when the absolute value of the current Ib has become larger than the threshold value Ibref for a predetermined time T1, it is assumed that the gear shifts to a shift speed other than the lowest shift speed. Is also good. In this case, the gear may be downshifted to a speed corresponding to the state of charge SOC of the battery 50, the battery temperature Tb, or the like.

  In the hybrid vehicle 20 of the embodiment, the transmission 60 uses a four-speed transmission. However, a three-stage transmission, a five-stage transmission, a six-stage transmission, or the like may be used.

  The correspondence between the main elements of the embodiment and the main elements of the invention described in the section of "Means for Solving the Problems" will be described. In the embodiment, the engine 22 corresponds to the “engine”, the motor MG1 corresponds to the “first motor”, the planetary gear 30 corresponds to the “planetary gear”, the motor MG2 corresponds to the “second motor”, and the battery 50 Corresponds to a “battery”, the HVECU 70, the engine ECU 24, and the motor ECU 40 correspond to a “control unit”, and the battery ECU 52 corresponds to a “deterioration degree estimating unit”.

  The correspondence between the main elements of the embodiment and the main elements of the invention described in the section of the means for solving the problem is as follows. This is merely an example for specifically describing a mode for carrying out the invention, and thus does not limit the elements of the invention described in the section of “Means for Solving the Problems”. That is, the interpretation of the invention described in the section of the means for solving the problem should be interpreted based on the description of the section, and the embodiment is not limited to the invention described in the section of the means for solving the problem. This is only a specific example.

  As described above, the embodiments for carrying out the present invention have been described using the embodiments. However, the present invention is not limited to these embodiments at all, and various forms may be provided without departing from the gist of the present invention. Of course, it can be implemented.

  INDUSTRIAL APPLICABILITY The present invention is applicable to a hybrid vehicle manufacturing industry and the like.

  Reference Signs List 20 hybrid vehicle, 22 engine, 23 crank position sensor, 24 engine electronic control unit (engine ECU), 26 crankshaft, 28 damper, 30 planetary gear, 29 transmission case, 36 drive shaft, 37 differential gear, 38a, 38b drive wheel , 40 motor electronic control unit (motor ECU), 41, 42 inverter, 43, 44 rotation position sensor, 50 battery, 51a voltage sensor, 51b current sensor, 52 battery electronic control unit (battery ECU), 54 power line, 60 transmission, 61 input shaft, 62 output shaft, 69 speed sensor, 70 hybrid electronic control unit (HVECU), 80 ignition switch, 82 shift position sensor, 84 accelerator pedal position sensor, 86 brake pedal position sensor, 88 vehicle speed sensor, MG1, MG2 motors.

Claims (1)

The engine,
A first motor;
A transmission connected to a drive shaft connected to the axle;
A planetary gear in which three rotating elements are connected to three axes of an output shaft of the engine, a rotating shaft of the first motor, and an input shaft of the transmission;
A second motor connected to the input shaft;
A battery configured as a lithium ion secondary battery and exchanging power with the first motor and the second motor;
Control means for controlling the engine, the first motor, the second motor, and the transmission such that a required torque required for the drive shaft is output to the drive shaft;
A hybrid vehicle comprising:
When the absolute value of the current of the battery is equal to or less than a predetermined current, a deterioration degree estimating unit that estimates the degree of deterioration of the full charge capacity of the battery,
Prepare,
When the absolute value of the current of the battery is larger than the predetermined current for a predetermined time, the control means may control a required power required for an input shaft of the transmission according to a required torque required for the drive shaft. Is output from the engine and means for controlling the transmission to be downshifted so that the current of the battery is equal to or less than the predetermined current .
Hybrid car.

Images